Bulletin Vol 24 No.3 Jun 2011

AMOS

AustralianMeteorological & OceanographicSociety

Bulletin of the Australian Meteorological & Oceanographic Society Vol 24, No.3, June 2011 ISSN 1035-6576

Contents — Volume 24 No. 3 June 2011

ISSN 1035-6576

Editorial...........................................................................................................................................................................53 President’s Column ........................................................................................................................................................53 News...............................................................................................................................................................................55 Conference Reports.........................................................................................................................................................56 News from the Centres...................................................................................................................................................60 Articles............................................................................................................................................................................62 M. Tomczak — Bird-assisted construction of wind roses......................................................................................................62 G. Readfearn — Climate scientist rappers reveal why they did it.........................................................................................67 D.White — Highest 24-hour rainfall ever measured in an Australian capital city...............................................................68

Meet a Member..............................................................................................................................................................72 Significant Mesoscale Oceanography............................................................................................................................72 Charts from the Past with Blair Trewin...........................................................................................................................75 Calendar..........................................................................................................................................................................76

ISSN 1035-6576 Cover picture: A silver gull flies past a fragmented circumhorizontal arc (or ice halo) in Williamstown, Melbourne. To see how these birds can help take meteorological observations, turn to page 62.

Image: Paul Randall (wingsonwire.com). Paul is a bird-watcher and photographer from Melbourne. His photos have been selected for use by the South Australia Museum and Museum Victoria. He also runs private workshops on bird photgraphy in the Melbourne area, which can be arranged through his website.

Image reproduced with kind permission.

Unless specifically stated to the contrary, views expressed in the Bulletin are the personal views of the authors, and do not represent the views of the Society or any other organisation or institution to which the author(s) may be affiliated.

Printed on 100% recycled paper.

Editorial

Communication validation The science of communicating climate change science gets bigger and bigger with every conference and every new finding about the alterations of the atmosphere. It is not enough to simply understand the science now.

Scientists are also expected — nay required — to help others understand, and share their findings with the world outside the ivory tower.

Sharing the science is not only as important as it has ever been, but the method of sharing is now much more complex than just a poster/presentation/paper combo. There are more online options for discussion and dissemination of information than ever before, and more and more opportunities for scientists to get involved in the education system and wider community. Heck, now we can even rap about our science!

Using plain language, clear graphics and accurate analogies, science can be made available to all. But of course, we know this. The recent increase in the number of seminars, books, workshops and dedicated conference sessions shows that the importance of communication is becoming a more natural part of the scientific system.

Now recent work from the National Climate Change Adaptation Research Facility (NCCARF) at Griffith University suggests that this focus on communication is paying off.

Over 3000 people from across Australia were interviewed about their opinions on climate change between June and July last year. Around 74% of those surveyed believed that the climate is changing and when asked about the causes of a changing climate, 90% of the participants agreed

that humans were at least partly to blame. The study also looked at how people answered a range of questions, and determined that less than 6% of those surveyed were serious climate change deniers. The same study was also undertaken in Great Britain, with very similar results.

These numbers are in stark contrast to the picture painted by many media outlets, claiming that Australia is still undecided on the topic of climate change. If you listened to Alan Jones’s interview with David Karoly late last month (or saw the associated Media Watch piece on the ABC), you might even think that the odds are the other way around.

This year the survey will be conducted again in both countries. In Australia’s case, it will provide a unique “natural laboratory” to see how the floods of early 2011 and the current political debate on a carbon price will influence people’s opinions on the existence and causes of climate change.

All of this is encouraging news, but it does not mean that we can afford to relax on the communication front. Now more than ever is the time to show the consistency of the science and help Australia understand the nature of this “diabolical problem”.

Linden Ashcroft Further information: www.nccarf.edu.au/public_risk_perceptions www.abc.net.au/mediawatch/transcripts/s3230989.htm

President’s Column

Climate change and the weather Whenever there is an outbreak of extreme weather — the Brisbane flood, the severe tornadoes in the USA, Tropical Cyclone Yasi, the Russian heat wave last year — people ask: “Is this due to climate change?” We respond with well-rehearsed answers: “No single extreme weather event can be attributed to global warming” or “No, the flooding is the result of the very strong La Niña event”. Of course we cannot usually rule out the possibility that the extreme weather is more extreme than in the past because of global warming, and for certain types of extremes (especially heat waves, and perhaps short-duration intense precipitation events) the prospect is for more frequent, or more extreme, events as the world warms. But generally the link between extreme weather events (the sort that lead to Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 53

disasters) and global warming remains problematic – with one exception. The exception is that improving the skill and use of weather forecasts, on time-scales from a few hours to the seasonal, might well be the most effective and efficient type of climate change adaptation available to us.

How can weather forecasts help us adapt to climate change? Well, if there is a prospect of more intense short-duration rainfall events, the sort that cause serious flash floods, then improving the technology we use to monitor and predict the movement of the intense storm cells observed on radar will provide the means to make better, and more timely, flash flood forecasts. So, even if the flash floods worsen with global warming, better use

of these technology forecasts would offset some of the consequences of the flooding. On a longer time-scale, the forecasters’ ability to predict areas with likely heavy daily rainfalls expected over the next few days has improved dramatically in recent decades and can be expected to continue to improve. These improved forecasts could be better integrated into riverine flood forecasts, and the operation of dams. Again, if these heavy rainfall events become more intense because of global warming, the improvement of the weather forecasts and their better use in flood mitigation would offset some of the deleterious effects. Even seasonal forecasts, in those regions and times of year for which these are feasible, can be exploited to reduce the impact of climate extremes such as La Niña events, perhaps by revising dam operation procedures when the next season is expected to be wetter than normal, or providing very early warning to operators of infrastructure likely to be damaged by extensive flooding.

And of course weather forecasts up to a week or more in advance have improved dramatically in recent years.

Already, many cities in Australia and overseas have been taking advantage of the improved temperature forecasts, by developing long-lead time (up to several days ahead) heat-wave alerts. These systems already save lives. As the number and intensity of heat waves increases these alerts will save more lives, and allow better use of resources such as ambulances.

Adoption of weather forecasting as a central plank in efforts to adapt to climate change has many advantages over other possible adaptations: 1. It is relatively easy (compared to many other types of adaptation), because it builds on already existing systems, namely national meteorological services.

2. It is cheap, primarily because it takes advantage of the existing systems, and builds on improving the forecasts and their uptake across communities.

3. It is targeted to the most dangerous aspects of climate change: the possible changes in extremes, i.e. those things that lead to disasters.

4. It is a “no regrets” adaptation — improved weather forecasts and better integration of these into decisionmaking, especially in disasters, would save lives and reduce damage now and into the future, even if the climate did not change.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 54

5. It doesn’t require “top down” action to enforce adaptation – simply improving the forecasts and publicising their improved skill will lead to their increased use in decision-making.

6. It doesn’t require major changes in the ways that people go about their activities. Many activities now employ weather forecasts in making decisions, so this adaptation is simply about increasing their use.

7. It doesn’t require huge investments in infrastructure (with the attendant risks of waste). Modest government investments in technology to allow continuous improvement in monitoring and forecast systems is all that is required.

8. It works even in situations where we have low confidence in projections of future climate change – we don’t need to predict if a specific extreme will become more frequent, in order to use weather forecasts as an adaptation tool. If, for instance, heat waves become more common then heat alerts based on weather forecasts would be issued more frequently.

The focus of questions such as “Will the weather become more extreme in the future” avoids the uncomfortable truth that we do a less-than-optimal job in avoiding the damage and deaths already caused by extreme weather.

In some cases this is because of a false perception that weather forecasts are not sufficiently accurate to use in disaster risk management. While this was a reasonable assumption in the past, rapid developments in weather forecasting, based on greatly improved prediction models and monitoring, mean that it is time for decision-makers to rethink whether or not modern weather forecasts should be integrated into their risk management. This will save lives and reduce damage now. But it will also help us cope with any worsening of extreme weather, as the climate changes.

Improving weather forecasts, and ensuring more extensive use of the forecasts in decision-making is the simplest, cheapest, best-targeted adaptation to offset the detrimental consequences of climate change. And if by some miracle the climate does not change, then all we have done is save lives and reduce the current costs of disasters – not such a bad thing.

Neville Nicholls

News

CSIRO launches climate change book Explaining climate change to the wider community is the aim of a new book launched by CSIRO at the April GREENHOUSE 2011 conference in Cairns.

we are currently •

Climate Change: Science and Solutions for Australia has been written for government, business and the public to help explain the many issues associated with climate change in Australia.

Energy saving technologies, demand reduction and distributed power generation will help to lower national carbon emissions

•

“This publication draws on the latest peer-reviewed literature contributed by thousands of researchers in Australia and internationally,” said CSIRO Chief Executive Dr Megan Clark at the launch.

Agriculture and forestry hold great potential for mitigating greenhouse gas emissions through afforestation, soil-carbon management, and better management of livestock and cropping emissions

•

Action within the next decade to lower greenhouse gas emissions will reduce the probability and severity of climate change impacts.

“It seeks to provide a bridge from the peer-reviewed scientific literature to a broader audience of society, while providing the depth of science that this complex issue demands and deserves.”

The book highlights the importance of climate change as a matter of significant economic, environmental and social concern in Australia and provides the latest information on international climate change science and potential responses.

The book can be downloaded for free from the CSIRO website, and has been widely distributed since its launch.

To download, visit: www.csiro.au/resources/Climate-Change-Book.

It is clearly laid out with chapters dedicated to climate change science, future scenarios and impacts, the pros and cons of adaptation, and mitigation. Some of the key findings discussed are: •

Evidence from many different sources shows human activities are contributing to the Earth’s changing climate

•

Some of the impacts of climate change on Australia are already apparent

•

We are committed to some degree of climate change as a result of past greenhouse gas emissions, so we will need to adapt on a far more extensive scale than

CSIRO Chief Executive Megan Clark launches Climate change: Science and Solutions for Australia.

“Well – the Bureau always gets the forecasts wrong anyway...how hard can it be?”

Sound familiar? AMOS gives you the chance to put your forecasting skills to the test in our annual Weather Tipping Competition.

It works like your office footy tipping competition but instead of winners, we want your predictions of minimum temperature, maximum temperature and rainfall. Locations change week-by-week — are you a better player at home or on the road? Among the players are some new recruits and seasoned campaigners, but can you beat the Bureau?

Entry is free and there are prizes at the end for the best-and-fairest. The competition is running throughout the footy season — all are welcome to play. Join up anytime and see how good at the forecasting game you really are! http://tipping.amos.org.au Or follow the link off the AMOS Home page Note: After nine rounds, the Bureau of Meteorology forecasts are ranked 13 out of 38 on the weather tipping ladder — Ed. Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 55

Conference Reports

First Ever NCL Workshops held in Australia April 2011 Mark Collier1 and Jason Evans2 CSIRO Marine and Atmospheric Research 2University of New South Wales Climate Change Research Centre

1

Recently two official National Center for Atmospheric Research (NCAR) Computing Language (NCL) workshops were held in Australia: the first in Melbourne (18–21 April), hosted by Mark Collier of CSIRO, and the second in Sydney (27–29 April), hosted by Jason Evans of UNSW. NCL is an analysis and plotting computer language that has become hugely popular in earth sciences world.

We were fortunate to have three leading NCL developers and trainers and long term employees of NCAR for each of the workshops: Dennis Shea, Mary Haley and Dave Brown. All three have a great knowledge of NCL and an enthusiastic approach to teaching, which has made them in strong demand. They have given workshops in South Korea, Turkey, Germany and Switzerland, as well as across the USA. There were 54 participants in the Australian workshops (see Table 1, Figures 1 and 2) who came from as far away as Darwin and Hobart.

The idea to hold a workshop began in May 2010 and organising the funding, selecting a group of participants and arranging a suitable venue and computing environment kept the organisers busy right up until the

week before each workshop. Mary Haley, the project leader of NCL was particularly excited about an Australia workshop as her parents had an exciting visit to Australia in the 1970s and it was a personal dream to make it herself.

It is expected that these workshops will create a groundswell in numbers of people using NCL in Australia in the future, and have a long-term positive impact on the quality and quantity of output by our scientific teams. It is also hoped that now there is a significantly large group of users in Australia, a community approach to using and developing tools based on NCL will occur. A wiki for local users has been developed and a separate page on the official NCL web page for Australian applications is planned. The workshop was a great opportunity for those people who could never find the time, motivation or the right learning environment to make a start with the language.

For the Melbourne workshop, a special thanks to Judy Jenkinson from the National Computing Infrastructure National Facility (NCI NF) for her tremendous help arranging workshop accounts and Mark Bervanakis from the Bureau of Meteorology for arranging a laboratory at

Figure 1. Melbourne NCL workshop participants, the Bureau of Meteorology Training Centre, Docklands.

Back row: Mai Nguyen, Vivian Huang, Mohar Chatttopadhyay, Hanh Nguyen, Lauren Stevens, Kim Nguyen, Andy Cottrill, Dragana Zovko Rajak, Dennis Shea (NCAR), Mary Haley (NCAR), Yuelong Miao, middle row: Arnold Sullivan, Tony Rafter, Petteri Uotila, John Allen, Matt Wheeler.

Front row: Tim Pugh, Greg Kociuba, Stacey Dravitzki, Dave Brown (NCAR), Tess Parker, Holger Wolff, Dörte Jakob, Pandora Hope, Tim Hume, Janice Bathols, Sarah Perkins, Mark Collier. Absent from photo: Stacey Osbrough, Maxwell Gonzalez.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 56

Table 1. NCL workshop participants with their principal affiliations.

Melbourne

Affiliation

Sydney

Affiliation

John Allen

Uni. Melb.

Simon Borlace

CSIRO

Janice Bathols

CSIRO

Kat Bormann

UNSW

Mohar Chattopadhyay

CSIRO

Irene Boyer-Souchet

UNSW

Mark Collier

CSIRO

Rebecca Buchholz

Wollongong Uni.

Andrew Cottrill

BoM

Claire Carouge

UNSW

Stacey Dravitzki

CSIRO

Ella Castillo

Katestone Environmental

Greg Kociuba

BoM

Hamish Clarke

UNSW

Maxwell Gonzalez

BoM

Laura Davies

Monash Uni.

Vivian Huang

Monash Uni.

Markus Donat

UNSW

Tim Hume

BoM

Ali Ershadi

UNSW

Pandora Hope

BoM

David Fuchs

UNSW

Dörte Jakob

BoM

Agata Imielska

BoM

Yuelong Miao

BoM

Fei Ji

NSW Dep. Of Premier and Cabinet

Hahn Nguyen

BoM

Edward King

CSIRO

Mai Nguyen

Monash Uni.

Yi Liu

UNSW

Kim Nguyen

CSIRO

Ian Macadam

UNSW

Stacey Osbrough

CSIRO

Penny Maher

UNSW

Tess Parker

Monash Uni.

Katrin Meissner

UNSW

Tim Pugh

BoM

Xianhong Meng

UNSW

Sarah Perkins

CSIRO

Simon Metcalf

Rural Fire Service

Tony Rafter

CSIRO

Matt Paget

CSIRO

Arnold Sullivan

CSIRO

Surendra Rauniyar

Uni.Melb.

Lauren Stevens

CSIRO

Seyed Shahrokhi

UNSW

Petteri Uotila

CSIRO

Ken Suber

CSIRO

Matthew Wheeler

BoM

Ben Sung

UNSW

Holger Wolff

CSIRO

Qinglong You

UNSW

Dragana Zovko Rajak

Uni. Melb.

Yifei Zhu

UNSW

the Bureau of Meteorology Training Centre (BMTC) in Docklands. Julie Siedses (CSIRO) assisted with numerous pre-workshop needs and the morning and afternoon teas during the workshop. Tony Hirst (CAWCR/CSIRO) coordinated the high-level planning of the workshop. For the Sydney workshop, a special thanks to Martin Thomson and Duncan Smith for preparing the computer laboratory.

Funding for the workshops were made available by the Centre of Excellence for Climate System Science and by the CSIRO Climate and Atmosphere Theme and Climate Adaptation Flagship, and the Centre for Australian Weather and Climate Research (CAWCR) .

A wiki has been created for an Australian Community of NCL Users and Contributors (see address below).

It is expected to be a relatively low-bandwidth page for Australians using and contributing to NCL tools specifically for Australian oriented earth sciences. It will: 1. be a starting point for people interested in using NCL Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 57

2. show examples of how NCL is being applied to solve Australian science problems, sometimes in a “bleeding edge” way 3. be a point of contact and exchange between Australian NCL users and contributors 4. allow for the fruitful exchange of ideas, data and scripts related to NCL and occasionally report back to the NCL developers in the USA. Please contact Mark Collier (mark.collier@csiro.au) if you would like further information including how to join the wiki. Partners external to CSIRO are encouraged to participate.

For further information: wiki.csiro.au/confluence/display/AustralianCommunityof NCLusersANDcontributors/Home www.ncl.ucar.edu

Figure 2. Sydney NCL workshop participants, UNSW. Back row: Jason Evans, Dave Brown (NCAR), David Fuchs, Ken Suber, Edward King, Matt Paget, Claire Carouge, Fei Ji, Yi Liu, Seyed Shahrokhi, middle row: Simon Borlace, Ben Sung, Ian Macadam, Agata Imielska, Kat Bormann, Penny Maher, Rebecca Buchholz, Yifei Zhu, Xianhong Meng, Qinglong You. Front row: Ali Ershadi, Surendra Rauniyar, Ella Castillo, Dennis Shea (NCAR), Mary Haley (NCAR), Laura Davies, Simon Metcalf, Hamish Clarke, Katrin Meissner, Markus Donat. Absent from photo: Irene Boyer-Souchet

GREENHOUSE 2011 4 – 8 April 2011, Cairns Kathy Pullman Comminucations Advisor, Australian Climate Change Science Program The sixth GREENHOUSE conference was held at the Cairns Convention Centre in April. Leading scientists from Australia and around the world presented the latest climate change developments to conference delegates.

The conference explored various climate change themes including trends, modelling, projections, observations, adaptation, communication, and policy and economic implications. It attracted: •

More than 470 delegates

•

29 keynote speakers/panellists

•

Almost 150 presentations

•

11 exhibits

•

60 parallel presentations

•

More than 90 climate science posters

•

Participants from 26 overseas countries

•

Significant sponsor support from nine organisations.

Some leaders’ key messages: •

Robust science is important for understanding and communicating effectively and accurately — The

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 58

Hon. Greg Combet, Minister for Climate Change and Energy Efficiency •

We need to be custodians of our planet as our country’s indigenous people are — Dr Megan Clark, CEO CSIRO

•

Everyone has the right to make up their own minds, but not the data — Dr Greg Ayers, Bureau of Meteorology

Prof Ross Garnaut, The University of Melbourne said: •

When we look at the science, there is very little doubt that there is a human footprint in the planet’s warming

•

It is crucial that we ground discussion in the mainstream science

•

We should be part of the global solution, not the global problem

•

We can’t do it alone.

Communicating to the community The conference confirmed that there is consensus about the cause of climate change among scientists but not the community. Leaders encouraged open and

factual discussion based on mainstream science. They also emphasised, as did other presenters, the need to communicate clearly and simply. Many acknowledged the difficulty of doing so with such complex subject matter that affects us all.

Media interest There were 19 representatives from key media and more than 60 climate change articles published in the print and electronic media during the conference. Conference Twitter followers quadrupled and within a few days there were almost 150 followers, including Kevin Rudd, the media, and other researchers.

Conclusion While consensus on the causes of climate change is yet to be reached outside the science community, we need to continue doing world-class science. We must continue to show how human activities have affected and are affecting our climate, what changes we have seen already, and what changes we can expect to see in the future.

Despite the avalanche of misinformation and lack of consensus, research has shown that there are still many people who want to support effective climate change action.

The science presented at GREENHOUSE 2011 will help decision makers, climate scientists, social scientists, industry representatives, and policy makers shape how we adapt to climate change and how we can reduce the impact of our activities on the Earth.

Prof Ross Garnaut addresses attendees at GREENHOUSE 2011

Many PowerPoint presentations from the conference can be downloaded at www.greenhouse2011.com/presentations.

Competition announcement: Student Essay Prize Deadline 5 September AMOS is seeking review essays on any topic of atmospheric or oceanographic science for the 2011 Student Essay Competition.

Entries are invited from current undergraduate university students (up to but not including Masters level).

Prize: $300 (Honourable mentions, $100)

Word limit: 5000

Target audience: Readers of the AMOS Bulletin

Deadline: Monday 5 September, 2011

Why not adapt your literature review or turn that assignment you have slaved over into an entry? You will give yourself a chance at winning $300 and of having a publication and prize to add to your CV. Finalists’ essays will also be published in the AMOS Bulletin.

Entries should be supplied via email as a pdf or in a format readable by Open Office, and accompanied by the entrant’s contact address, university enrolment and a declaration that the essay is the student’s own work.

Past copies of the AMOS Bulletin may be downloaded from: www.amos.org.au/publications.

For more information, visit: www.amos.org.au/education or email Philip Riley at p.riley@bom.gov.au.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 59

News from the Centres

Public Forum: Southeast Queensland’s future weather and climate Johanna Speirs AMOS Brisbane Centre

Floods, cyclones and severe storms have devastated much of Queensland in the space of a few short months and many people are now questioning whether this is a result of climate change or natural climate variability. To address some of these questions, the AMOS Brisbane Centre held a one day forum on 12 April 2011, titled “Southeast Queensland’s Future Weather and Climate: What it Means for Industry, Government and the Community”. The forum was held at the Queensland Museum and brought together experts in southeastern Queensland weather, climate, air quality and coastal processes to present talks for a broad audience of environmental managers, engineers, students and other members of the community. Talks were followed by a moderated panel discussion on how emerging weather and ocean trends might constrain landuse planning and air quality in southeast Queensland.

Topics of the presentations: Welcome Address — Honourable Kate Jones, Queensland Government Minister for Environment and Resource Management (Figure 1) Thunderstorms: Expected Trends — Bruce Gunn,

Figure 1. The Honourable Kate Jones providing the welcome address.

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Bureau of Meteorology Climate Variability: Implications for Southeast Queensland — Associate Professor Hamish McGowan, The University of Queensland (Figure 2) Tropical Cyclones: A real threat to Southest Queensland?

— Jeff Callaghan, The Bureau of Meteorology (Ret.) Southeast Queensland Metropolis: Its emissions and Weather — Robin Ormerod, PAEHolmes Pty Ltd Southeast Queensland susceptible to erosion and inundation? — Associate Professor Ian Goodwin, Macquarie University This forum was hosted by the Australian Meteorological & Oceanographic Society (Brisbane Regional Centre) with additional support from the Climate Research Group, School of Geography, Planning and Environmental Management, University of Queensland and Katestone Environmental Pty Ltd. PDF copies of the presentations are available from the AMOS website and www.gpem.uq.edu.au/crg-amosforum.

Figure 2. AMOS Brisbane Chair and Associate Professor Hamish McGowan from the University of Queensland.

ACT Branch news Clem Davis

Secretary/Treasurer, AMOC ACT Centre The ACT branch held its Annual General Meeting and dinner at Vivaldi’s restaurant at the ANU on 22 March 2011 and twenty three people attended (19 members, two spouses, guest speaker and 2010 student prize winner).

As well as the usual reports and electing a new committee, the 2010 student prize winner (Shirley Qin) was presented with her prize and a certificate (see Figure 1).

The new committee for ACT Branch is: • • • • • •

Margi Bohm (President) (University of Canberra/ CSIRO) Clem Davis (Sec/Treasurer) Annette Hirsch (CSIRO) Bob Cechet (Geoscience Australia) Robin Robertson (ADFA) Gavin O’Brien (Southside Weather)

3. Continuing to hold 3 to 4 themed members meetings for the year 4. Encouraging more student memberships and having a greater involvement with the community 5. Reorganising our AGM in line with the new AMOS rules. This will mean that we will hold another AGM at the end of the year, probably along with a Christmas function.

Our guest speaker, Dr Matthew Brookhouse from ANU, provided a very interesting talk on dendrochronolgy (i.e. tree rings and climate) with regard to Australia and the pitfalls involved.

Margi spoke about the centre’s plans for this year which include: 1. Updating the website 2. Running a one day workshop on global warming during National Science Week

Figure 2. 2011 Committee: Annette Hirsch, Margi Bohm,Clem Davis, Bob Cechet, Gavin O’Brien and Robin Robertson.

Figure 1. Margi presenting Shirley with student prize.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 61

Figure 3. Clem and guest speaker Dr Matt Brookhouse.

2011 Pearman Lecture Damien Irving

AMOS Melbourne Centre The Pearman Cup is an annual event hosted at CSIRO Marine and Atmospheric Research (CMAR) in Aspendale.

Staff from the meteorological and oceanographic research divisions of CSIRO, Bureau of Meteorology, Monash University and the University of Melbourne come together to enjoy a keynote lecture, followed by a beach volleyball tournament. Named in honour of Graeme Pearman, a former Chief of CSIRO Atmospheric Research, the Cup was first held in 2005.

In recent years, the number of people staying on after the lecture has been dwindling, which has detracted from the social aspect of the evening. The regular lunchtime volleyball players at CSIRO claim that this drop in numbers is due to the dominance of the CSIRO team, however other more impartial AMOS members suggest that beach volleyball isn’t a sport that many people are confident in playing. As such, the post-lecture volleyball tournament was replaced this year with social drinks and nibbles in the CMAR cafeteria.

The 2011 Pearman Lecure itself was delivered by Professor

Ian Simmonds, who spoke on the topic of recent observed changes in the climate of the polar regions. Throughout a long and distinguished career, Professor Simmonds has published extensively on the climate of the Antarctic and Arctic regions, including a recent article in Nature on the mechanisms underlying the recent Arctic temperature amplification (Screen and Simmonds, 2010). The lecture was very well attended, with approximately 30 to 40 people staying afterwards to further discuss the polar climate and to catch up with colleagues.

While the AMOS Melbourne Centre was very pleased with the increased social aspect of this year’s event, we are open to reviving the volleyball tournament next year, if there is sufficient interest from each research institution.

Reference Screen, J.A. and Simmonds, I. 2010. The central role of diminishing sea ice in recent Arctic temperature amplification. Nature, 464, 1334–1337. doi: 10.1038/ nature09051.

Articles

Bird-assisted construction of wind roses Matthias Tomczak

School of the Environment, Flinders University, Adelaide Address for correspondence: matthias.tomzak@flinders.edu.au Abstract A method to use data collected from resting places of birds for the improvement of wind statistics is described.

An example of its application is presented. Various shortcomings are discussed, with suggestions for improvement of the method.

Introduction Wind roses are a convenient means to present wind observations over an extended period in a concise and informative manner (Ahrens, 2002). Their most common use is in the construction of airport runways (Horonjeff et al., 2010). They have also been used to document pollution in urban areas (McKendry, 1993) and more recently in the assessment of potential sites for wind energy (Al-Abbadi, 2005). Wind roses can be built from continuous records or from datasets that contain observations only for certain observation times, e.g. 9 am and 3 pm. However, their use is restricted to locations where observations are available. This limits the area coverage of wind roses for the characterisation of prevailing wind conditions to the density of the observational station network.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 62

This paper shows that under certain conditions wind roses can be generated at no cost through the combination of favourable building characteristics and helpful behaviour of endemic fauna.

Method The observations reported here come from the jetty in Brighton, a suburb of Adelaide, South Australia, on St. Vincent Gulf.

The old Brighton jetty was a wooden structure set somewhat low against mean sea level. During winter storms high waves regularly caused planks to be lifted from the jetty and float away. In 1993 council engineers placed beams along the sides of the jetty on top of the planks to keep them in place, apparently unaware of the well documented effect of the vertical force of breaking waves (Defoe, 1719, among others gives a clear account, and von Boguslawski and Krümmel, 1887, report that the vertical force of breaking waves can be several orders of magnitude larger than their horizontal force). As a result, the first winter storm of 1994 lifted entire sections from the jetty, which then floated away. Figure 1 shows the jetty

Figure 1. Brighton jetty during the winter storm of 1994.

Figure 2. The new Brighton jetty. Its orientation in space is indicated.

during the storm; one section has already floated away along the coast, a second one is just being removed.

surface and the jetty orientation provide ideal conditions for bird-assisted wind roses.

The demise of Brighton’s major seaside attraction led to the closure of several cafés and restaurants in Jetty Road and to a general decline of the local economy, until a mobile phone provider offered to subsidise the construction of a new jetty, if it could include a mobile phone tower for recreational boat traffic in the Gulf. The new structure, which led to rapid recovery of business on Jetty Road, is of concrete construction and stands about 1 m higher above mean sea level than the old jetty. In the context of this paper the major improvement is the addition of a row of lamp posts on the southern side of the jetty (Figure 2).

The combination of the posts, the uniform concrete jetty

The shape of the lamp posts, which presumably was selected for aesthetic reasons, makes the posts ideal resting places for the many seabirds that frequent the Brighton shoreline.

Silver gulls (Chroicocephalus novaehollandiae) are the predominant users of the posts, but little cormorants, various terns, and other sea birds have also been observed to rest on them. The resting position of all birds in environments exposed to strong wind is determined by the aerodynamic requirement to reduce body drag to a minimum (Bartholomew, 1943), which means that birds resting on the lamp posts face into the wind (Figure 3).

As a consequence, given the prevailing south-westerly

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 63

winds and the orientation of the jetty, which points nearly exactly west (Figure 2), any droppings released from the resting birds land on the jetty. The exact position of impact is determined by wind speed and direction. This forms the basis of the bird-assisted wind rose technique.

An essential condition for the generation of bird-assisted wind roses is good contrast between the observational markers and the canvas. Piscivorous birds produce nearly exclusively white markers of high nitrogen and phosphorus content or “guano�, a result of their diet (Breuning-Madsen et al., 2010). Although the concrete deck of Brighton jetty is not black it is of uniform colour and provides a sufficiently dark canvas to create an acceptable contrast.

 3. A Pacific gull (Larus pacificus), a rare collaborator of the birdFigure assisted wind rose project, in sampling position.

Results This section demonstrates the new wind rose generation method with some examples from October 2010. Figure 4 shows a wind rose generated during fairly steady southwesterly wind conditions. Some data points along the railing indicate weaker westerly winds before the onset of the sea breeze, which leads to an increase in wind speed and the turning of the wind direction towards south-west.

The effect is more pronounced in Figure 5, which displays a situation with three dominant wind directions and highlights the progressive development of the sea breeze and freshening of the wind in colour.

For quantitative statistical studies it is important to discount small markers produced by spattering at the moment of impact of the original marker. Errors produced by spattering affect both wind direction and wind strength estimates. Figure 6 shows a wind rose from a period when the wind shifted from westerly to south-easterly as a high pressure system passed south of the Gulf. Many of the small markers have to be discarded as false measurements. They can be eliminated through the use of pattern recognition Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 64

software (Fukunawa, 1990) if a minimum marker size is set as a detection threshold.

Discussion The examples of bird-assisted wind roses presented in the previous section demonstrate the potential of the new method of wind rose construction. Several issues have to be addressed before the method can be considered faultless.

They can be separated into limitations of the design that cannot be overcome, and limitations of accuracy that could be addressed through further development of the method.

One clear limitation of the method results from the positioning of the lamp posts. Figure 7 shows wind roses from Adelaide airport, located 8 km to the north of Brighton jetty and within 2 km of the coast. Although the prevailing winds are from the southern sectors, winds with a northerly component are not uncommon. To include northerly winds in the generation of bird-assisted wind roses would require the relocation of the lamp posts to the centre of the jetty, a change unlikely to be acceptable to the council for reasons of pedestrian safety. In any case, it is doubtful whether relocation of the posts would lead to much improvement, since most observations of northerly winds are related to the land-sea breeze cycle and occur at night, when the birds return to their roosts and the birdassisted wind rose system is not operational.

Another limitation of the method is imposed by the width of the jetty, which limits the range of wind speeds accessible to measurement. Figure 8 shows a wind rose from 30 October 2010 after a storm produced by the passage of a front. While the birds were actively producing markers during the event, some of the markers were not recorded on the jetty surface but ended up on the beach. Note that even most markers close to the railing are true records of wind speed and not the result of spattering. Widening the jetty could of course increase the measurable wind speed range, but the cost would be significant.

Other limiting factors, some bird related, others related to the behaviour of the general public, could be addressed at less expense. Both affect the continuous sampling

Figure 4. A wind rose generated during steady south-westerly wind.

Figure 5. A wind rose generated during pronounced sea breeze conditions.

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Figure 6. A wind rose generated during conditions of variable winds.

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Figure 7. Wind roses for Adelaide airport, based on the 24 months 1999-2000 (EPA SA, 2004).

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 65

References Ahrens, C.D., 2002. Meteorology Today: An Introduction to Weather, Climate, and the Environment, 7th ed. Brooks/ Cole, Pacific Grove CA, 624 pp.

Al-Abbadi, N. M., 2005. Wind energy resource assessment for five locations in Saudi Arabia. Renewable Energy, 30, 1489–1499.

Bartholomew, G.A. Jr., 1943. Contests of Double-Crested Cormorants for Perching Sites. The Condor, 45, 186–195.

Boguslawski, G. von and Krümmel, O., 1887. Handbuch der Ozeanographie vol. II. J. Engelhorn, Stuttgart, 766 pp.

Figure 8. A wind rose produced under very strong wind conditions.

of the evolving wind conditions, which requires the uninterrupted presence of sampling birds on the same lamp posts. Pedestrian traffic often causes birds to leave their posts or change posts to gain more distance from people. While the birds usually return to their original perching location, any temporary change of location results in gaps in the record and reduces the statistical significance of the wind roses (see Figures 5 and 6 for examples).

To avoid observation gaps, the public could be instructed to walk close to the northern railing. Should this not result in sufficient distance from the birds and the birds continue to be alarmed by pedestrians and driven from their posts, the jetty could be closed to pedestrian traffic. Even such far-reaching action would not guarantee the elimination of sampling gaps, because birds have been observed to come and go at their leisure. A systematic bird training program would be required to guarantee continuous sampling.

Bird training techniques involve dispensing food as reward for training success (see for example Terrace, 1963). In the case of Brighton jetty the necessary food supply could be secured by recruiting some of the people fishing on the jetty as volunteers, supervised by a bird behaviourist.

Offering fish in return for continuous marking would also guarantee the birds’ ability to produce markers over extended periods.

In summary, it has been shown that in regions of infrequent rainfall exposed coastal structures with high perching facilities can be used to produce wind rose data at negligible expense, by taking advantage of the markings produced by bird droppings.

Acknowledgements My thanks go to R. W. Sheldon and R. Kerr, whose study of monster numbers in Loch Ness (Sheldon and Kerr, 1972) encouraged me to apply the scientific methods of oceanography to other problems of daily life, and to Chris Tomczak for her encouragement during this research.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 66

Breuning-Madsen, H., Ehlers-Koch, C., Gregersen, J., and Lund Løjtnant, C., 2010. Influence of perennial colonies of piscivorous birds on soil nutrient contents in a temperate humid climate. Geografisk Tidsskrift Danish J. Geogr, 110, 25–35.

Defoe, D.,1719. Robinson Crusoe. W. Taylor, London, 320 pp.

EPA SA, 2004., Meteorological Data Files for the Ausplume Air Dispersion Model. Environment Protection Authority of SA, Ref No 20030765RA1B (unpublished manuscript), 42 pp.

Fukunawa, K.,1990. Introduction to Statistical Pattern Recognition, 2nd ed. Academic Press, San Diego CA, 592 pp.

Horonjeff, R., McKelvey, F.X., Sproule, W.J. and Young, S.B., 2010. Planning and Design of Airports, 5th ed.

McGraw-Hill, New York, 688 pp.

McKendry, I., 1993. Ground-level ozone in Montreal, Canada. Atmospheric Environment. Part B. Urban Atmosphere, 27, 93–103.

Sheldon, R.W. and Kerr, R., 1972. The population density of monsters in Loch Ness. Limnol. Oceanogr. 17, 796–798.

Terrace, H.S., 1963. Errorless transfer of a discrimination across two continua. J. Exp. Anal. Behav. 6, 223–232.

Climate scientist rappers reveal why they did it Graham Readfearn WHEN asked about the key climate change issues, IPCC lead author Professor Roger Jones echoed the concerns of colleagues by saying: “Feedback is like climate change on crack. Denialists deny this in your dreams, Coz climate change means greater extremes.”

“S*** won’t be the norm,” added others.

If only all interviews on climate change could be this colourful, this frank and this… well… lyrical?

In May, Australian ABC show Hungry Beast screened an original rap video staring nine actual climate scientists, complete with “mutha f******”, a slammin’ gangsta baseline

The group of scientists were approached to take part by Ilic, who has been behind several successful viral satirical videos for community advocacy group GetUp and other campaigns.

Jason Evans, of the University of New South Wales Climate Change Research Centre, says the offer to take part was hard to refuse, given he is a “closet rap fan” from way back.

Finally allowed to release his inner Beastie Boy, Evans, who researches past and future impacts of climate change at regional levels, slams the first line “yo….we’re climate scientists.. and there’s no denying this: Climate Change is REEEEALL.” He’s also had his fair share of engagement with climate sceptics, although none quite like this. “You can’t be a researcher in this business for long without having to have exchanges with sceptics or deniers,” he says. “But then it also doesn’t take long for you to realise you are wasting your time,” he adds. Evans used to reply to sceptics with copies of peer-reviewed research, but these days he sees little point.

“They have made their mind up so it’s pointless engaging and, anyway, all my work is publicly available. This was really a much more fun and light-hearted way to get that message across.”

A still from the “I’m a Climate Scientist” video (Source: Hungry Beast) and scores of peer-reviewed science papers and decades of research to back it up.

Since the original rap was posted on YouTube and other blogs, the video has been viewed more than 155,000 times and reposted on sites in the UK, Australia and the USA, including the Huffington Post, one of the world’s most popular blog sites.

For a viral online clip which features neither Justin Beiber, Charlie Sheen, Osama Bin Laden or the unlikely and hilarious antics of domesticated cats, this is a remarkable return.

Hungry Beast presenter, comedian Dan Ilic, co-creator of the clip, told me he had “basically blackmailed” the climate scientists into taking part by threatening to “burn a pile of 100 spare tyres” if they didn’t do it.

“I was actually very surprised they agreed but some thanks goes to my producer for helping to get it over the line,” he adds. To write the lyrics, Ilic consulted the group to ask what the key issues were on climate change. “They told me that it’s real and it’s happening. They talked about how climate feedbacks are an extraordinary thing,” he says.

“When permafrost melts there’s a stack of methane that’s released which just adds exponentially to the problem”, hence the lyric “Feedback is like climate change on crack” .

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 67

Evans says that the hardest bit to rap was the line “Denialists deny this in your dreams, Coz climate change means greater extremes, S*** won’t be the norm, Heatwaves bigger badder storms”. But then he revealed that after he and colleagues spent an hour and half recording the audio for the track, their voices were not used in the end.

“That may tell you something about our actual rapping ability. We were just the pretty face on the front… but we are working on our first album,” he added, worryingly.

Dr Ailie Gallant, a University of Melbourne researcher in climate change and climate variability, says she took part because it “highlighted the issue of unqualified opinions on climate science by politicians, economists etc. in the media”. She also thought it was funny.

There were others who didn’t think it quite so hilarious.

After undergoing a collective sense of humour bypass, climate sceptic bloggers including Tim Blair, Andrew Bolt, Anthony Watts and Steve McIntyre all grumbled disapprovingly.

“I’m not perturbed by those who deride it — it’s just satire,” says Dr Gallant. “Contrary to popular opinion, not all climate scientists are serious old men in lab coats; we are real people and we do have a sense of humour. In saying that, I think the job of satirical humour is to make people laugh, but then to make people think. I hope Hungry Beast’s rap makes people think about the importance of

considering who is presenting opinions on the science of climate change in the media.”

smoking simply because they are “too hard for people to contemplate”. The second category is “offensive” denial.

Victoria University’s Professor Roger Jones, the elder statesman in the video who also finds time to be a lead author for the IPCC, agreed to take part in the gansta rap smash even though he says his “guilty pleasure is actually metal”.

“Offensive denial shows someone’s blind self interest where they’re willing to invest time and money as the tobacco industry has and certain people are now doing, to delay decision making and confuse the evidence. For a while, the scientific community has been left behind.

“I did it because I knew it was going to be fun,” he says, adding that he also decided to do it because he realised that most other senior professors his age would probably have said no.

“The video was always going to be offensive at some level.

I take my offense at offensive denial. A bit of profanity I don’t really give a rats about. Those are just social mores.

“This has been a real topic in the science community more recently — why do people believe certain things. It is increasingly clear to the scientific community that the so-called rational form of decision making is only utilised by some people, some of the time.”

Professor Jones says he generally splits forms of denial into two different categories. One is “defensive” where people deny the evidence of the risks of burning fossil fuels or

“One of the best ways to learn about hornets is to poke the nest. In a way, this is a bit like that.”

This article was originally published on Graham’s blog www.readfearn.com on May 13, 2011. It has been reproduced with kind permission.

To see the Hungry Beast video, which stars a number of AMOS members, visit http://youtu.be/H7wdKg8rYL0.

Highest 24-hour rainfall ever measured in an Australian capital city Don White

Weatherwatch (Aust) Address for correspondence: donwhite@weatherwatch.net.au The highest ever 24-hour rainfall in an Australian major city occurred at South Head (the Hornby Light, as it was then called), Sydney with 20.41 inches (518.4 mm) on Tuesday 15 October 1844. The rain actually fell in the 24 hours ending 8.30 am on Wednesday, 16 October 1844 but the observations at the time were based on the day of the event:

no daily total exceeded 76 mm. However, this type of variation between Dural and South Head is possible from the descriptions of the weather at the time. Their monthly total was 228.6 and annual total 987.8 mm.

This site reported until 1918 but there are only 30 complete years — and October 1844 was the second wettest October in that time.

During the week, a total of 606.8 mm of rain fell (see Table 1). For the month of October, 627 mm were recorded —more than double that in any other October in the last 150 years (Bureau of Meteorology, 2011). In the year of 1844, South Head recorded 1795 mm; data from this station extends from March 1840 to December 1854 and in 1867 and 1868 and during all those years, the site averaged 1246 mm annually. This is comparable with Sydney’s average annual rainfall up to today.

Since 1844, the heaviest daily falls in the Sydney region have been 386.3 mm at Pitt Town (in the far northwest suburbs) on 28 May 1889; 383 mm at Turramurra on 28 March 1942 and 340 mm at Sydney Botanical Gardens on 6 August 1986. The highest daily fall in any other capital city has been 475.8 mm at Enoggera Reservoir (Brisbane) on 26 January 1974 and 465.1 mm in Brisbane City on 21 January 1887.

Only two other sites in New South Wales were reporting meteorological data in 1844: 1. Port Macquarie on the NSW mid north coast. In 1844, Port Macquarie had 1642 mm. In October, just 17.5 mm were recorded at Port Macquarie. Only 5.8 mm fell in the week to 14th and just 0.3 mm for the rest of the month.

2. Dural School — 19 km northwest of Sydney Town.

In the week to 17 October 1844, 208.3 mm fell but Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 68

On 29 April 1841, there was a report of 20.12 inches (511 mm) in 24 hours at South Head. The only additional information I have tracked down on this event stated: “The extraordinary quantity of rain which fell on 29 April 1841 occurred when the wind shifted so frequently in squalls between E.N.E. and E.S.E. it was impossible to ascertain their relative proportions.” (Sydney Morning Herald, 24 May 1842).

In an endeavour to put together the type of weather pattern that was responsible for such a deluge in October 1844, the weather data for the period from the 9th to the

18th was looked (see Table 1 and 2) as well as the observers’ description of the weather conditions over the same period (Table 3).

The information available on the instrumentation used at South Head at that time comes from a quoted report by the observer that was published in the Sydney Morning Herald on 4 May 1845 (Page 3): “The rain gauge is cylindrical 6 inches (15 cms) in diameter, having a funnel lid with sides 2 inches (5 cms) deep, then decreasing to a tabular hole of half an inches (1.25 cms) in diameter to prevent as much possible evaporation and other decrease or extraneous augmentation. It is placed on the ground in a perfectly open situation.”

A further report in the Sydney Morning Herald on Friday 18 October 1844 states:

“We do not recollect such tempestuous weather as we experienced from Tuesday morning to Wednesday morning, having occurred during our, by no means short residence in the colony. The violence of the wind and the torrents of driving rain reminded us of the weather which occasionally rages in England but was by no means in character with the mild south. But not satisfied with our own recollection, we spoke to the ‘oldest inhabitant’ (We take Joshua Allcott of the Supreme Court to have a fair claim to that title) and he did not recollect such a day as Tuesday. The ‘slop built’ houses of Sydney suffered very much. The rain actually drove through the walls and very few of the roofs were water tight. The amount of damage thus done on a small way was considerable, but we have not heard of any serious accidents. On Wednesday afternoon the weather moderated and yesterday was a mild, drying day.”

Table 1. Weather observations from South Head, New South Wales from Wednesday 9 to Friday 18 October, 1844. Conversions used: 1 inch (mercury) = 33.864 hectapascals (pressure), 1.00 inches = 25.4 mm (rainfall), °F to °C: C = 5(F-32)/9 (temperature).

Date

Barometer

Wed 9

Detatched thermometer 2100

Wet therm.

0830

1430

sunset

0830

1430

sunset

2100

1430

Rain

Winds

1011.5

1010.8

1010.5 1010.8 21.1

22.8

17.8

16.7

20.0

-

NNW, NNE, N

Thu 10 1010.8

1010.8

1010.5 1015.6 22.2

26.7

19.4

18.3

20.6

0.8

N, N by W, NNW, N

Fri 11

1011.2

1011.2

1011.2 1012.2 22.2

24.4

14.4

15.0

21.1

18.6

N, S

Sat 12

1013.5

1013.5

1013.2 1012.9 17.2

16.7

16.1

15.0

15.0

10.4

S, SSE, S by E, SE by S, S

Sun 13

1012.5

1006.4

1005.4 1006.1 15.6

16.7

13.9

13.9

15.6

23.6

SSW,S by W,S,SSE,S

by W

Mon14 1008.5

1010.2

1009.8 1010.5 13.3

13.9

13.9

13.9

13.9

8.6

S by W, S,S by E,S, SE

by S

Tue 15

1010.2

1006.1

1004.4 1005.8 13.9

12.2

12.2

11.1

11.1

518.4 Vide Infra (see below)

Wed16 1006.8

1009.8

1010.8 1012.2 11.7

12.8

12.2

11.1

12.8

26.4

S by W, S

Thu 17 1012.2

1011.5

1011.2 1011.2 13.3

15.0

12.8

11.7

13.9

-

SW by W, SE, ESE

Fri 18

1014.9

1015.2 1016.9 16.6

17.8

18.3

14.4

15.6

-

SE, NW, SE

1015.2

Table 2. Notes during the gale of 15 October, 1844. Conversions used as the same as Table 1.

Hour

Barometer

Detached Thermometer Rain fallen

Cumulative Rain

Wind

0830

1010.2

13.9

SE; S

1430

1006.1

12.2

S by E; SSE; S by E

1500

1006.1

12.2

88.4

1700

1005.1

12.2

137.2

Sunset

1004.4

12.2

S; SSW; SW by S 225.6

SW; S; SW SW by W

1830

1004.7

11.1

35.4

260.0

SW

2100

1005.8

11.1

38.9

298.9

SW

2230

1006.1

11.1

68.1

367.0

SW by S

0700 (16th)

1004.4

11.1

151.4

518.4

S by W

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 69

Table 3. Weather notes and observations from Wednesday 9 to Friday 18 October, 1844. The observer is Mr J.F. Peacock (as published in the Sydney Morning Heralds of 16 and 28 October 1844. He was also known as George Edwards Peacock). Conversions used as in Table 1.

Date

Notes and Descriptions

Wed 9

Calm and sultry early part and hazy to northward. Cirri (sic) in zenith. Vane north-north-west; wore (midday) round to north-north-east and blew freshly from that quarter. PM atmosphere cloudy and getting very damp with a thick haze. Night — north, moderate.

Thu 10

Morning close and muggish and dead calm and remained nearly calm all day; atmosphere clouded and continued heavy and sultry with some light warm rain at intervals. Thermometer 28°C in shade at 1 o’clock; latter part clouds gathered with a murky aspect from north-north-west. Night close and sultry.

Fri 11

Morning calm and foggy and continued gloomy and muggish till afternoon; when gather up, very heavy from southward and between 3 and 4, cool, refreshing southerly breezes arose; scud flying quickly and moderate rain fell.

After sunset, clouds assumed a most dense form and extended in a low, uniform heavy mass across the heavens and rain set in; between 7 & 8 an awful storm of thunder and lightning accompanied by violent rain commenced; the lightning exceedingly vivid, one flash in particular about 8.30 which was instantaneously followed by a most remarkable clap of thunder, resembling at the outset a sharp rolling of musketry discharged in the room, which caused an involuntary start and then immediately followed by a heavy discharge of cannon at uneven intervals and a rumbling was heard for two or three minutes; indeed, it was only lost in a succeeding clap; after this the storm gradually subsided, passing off between north and north-west..

Sat 12

Light wind all this day; clouds very low and murky but little rain. Afternoon became very foggy and dirty and a misty rain commenced and continued with scarcely any intermission through the night which was dark and dismal.

Sun 13

Morning calm; thick fogs and rain all forenoon; middle part no rain; clouds turbid and hanging very heavily all around; around 4 o’clock the wind freshened from southwards and rain began to fall heavily and continued all night more or less; wind blowing strong and coarse.

Mon14

Strong southerly breezes throughout; atmosphere densely charged with fog and nimbus and drizzling rains all day. Evening wind rose and blew widely all night. Clouds dark and stormy but little rain.

Tue 15

Blowing strong and wildly from SSE all morning; atmosphere densely charged with nimbus and fog; only occasional spitting rain between 10 and 11 am, when clouds assumed a strong threatening character and rain set in heavily.

Noon came on to blow a gale and rain began to beat with violence and so continued from E of S until 2.30 to 3 pm accompanied by a thunderstorm which passed in the zenith. Towards 3 o’clock the wind veered around to the SSW and a brief subsidence occurred during which the rain poured in deluging torrents!

The gale, however, soon burst upon us with renewed and terrific force from SW by S to SW, the rain now driving with devastating impetuosity. Thus it lasted until 6 o’clock, when there was an abatement, winds wearing more westerly. The quantity of rain fallen between 3 & 5 pm was no less than 137 mm!!

Sunset continued violent driving rain, gale increasing. 6.30 no change. 9 o’clock gale latterly much heightened, blowing in a most impetuous manner with heavy beating rain. 10.30 blowing still a furious gale from about SW. Rain violent and incessant. Scarcely any change took place before midnight; after that time rain not quite so heavy; but the gale continued to rage in an impetuous manner all though the night backing to the SSW in the latter part.

By 7 am on 16th, though the gale was still very violent (from S by W) the rain had much abated and the quantity fallen since 10.30 (night) was 151 mm but I ought to observe that on measuring the rain gauge at 7 o’clock, I found it literally full and my impression was that it had been overflowing, but whether so or not and if so, for how long, it is an insolvable problem.

Be this as it may, the aggregate measured quantities fallen between 8.30 am on 15th and 7 am on 16th make a total of 518.4 mm in 22½ hours. Indeed, up to 10.30 on 15th, there could not be more than 2.4 mm — the rain being only a trifling spitting the period may fairly be reduced to 20½ hours and the quantity fallen taken as 516 mm or 25 mm per hour! Had I not proof of this fact by ocular demonstration and carrying in my recollection also the equally astonishing and very similar quantity (511 mm) which fell here on 29 April 1841, I could hardly of credited it in as much as no other record of rain I have had to make during 4 years and a half, will bear the least comparison with either of these. On that occasion, the wind varied from ENE to ESE blowing in stormy gusts but no near so violent as this last gale has been.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 70

Table 3 continued.

Date

Notes and Descriptions

Wed 16

Continued hard gale from S by W all afternoon; after 7 o’clock the rain was comparatively little coming in squalls at intervals only; and dense clouds began to break, admitting occasional gleams of sunshine.

Midday, gale began to subside and between 2 and 3 wholly lulled for a space then after one squall, it ceased; clouds cleared off gradually, the cheering blue sky first dawning in the SW. Afternoon clear and pleasant with light southerly airs.

Thu 17

Morning cirro-stratus and gentle SW breezes. Afternoon light SE wind and delightful clear weather.

Fri 18

Light SE airs through the day except an interval of calm in a.m. when vane stood NW. Clear pleasant weather.

It is also possible that the actual rainfall could have been even higher. In his report to the Governor on 17 October, the observer, Mr Peacock stated: “I ought to observe that on measuring the rain gauge at 7 o’clock, I found the instrument within one tenth of an inch of being full and my impression was that it had been overflowing insomuch as the space occupied by the funnel proved to be equal to nearly one tenth of an inch.

How much if any had overflowed, is a problem not easily solved.”

Conclusion October 1844 was not a typical Spring month in Sydney Town. A market report in the Sydney Morning Herald on 18 October stated: “Owing to the prevalence of easterly winds, the arrivals of colonial wool have been later than usual this season.” The weather had been warm and very humid up to the arrival of a southerly change on Friday 11th. The weekend weather seemed to be typical of an upper cold pool, probably to the southwest of Sydney. It appears that this developed explosively as it crossed the coast close to Sydney on the morning of Tuesday 15th. The presence of coastal thunderstorms would support this and while the absence of wind strength data is restrictive, description of the weather indicates considerable strength and low temperatures (a maximum around 12°C on Tuesday 15th).

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 71

This would also support the idea of an east coast low developing very close to or just to the south of Sydney, as indicated by the westerly component referred to in the wind direction (Table 2). The description of Wednesday’s weather is in keeping with the idea of the low moving quite rapidly away to the southeast. It is likely that rainfall in Sydney Cove was considerably lower than on the coastal fringe at South Head but it is likely, from the description of the minor damage, that it was still significant.

References Bureau of Meteorology, 2011. Monthly Rainfall at Sydney Observatory (066062). Available from www.bom.gov.au/ jsp/ncc/cdio/weatherData/av?p_nccObsCode=139&p_ display_type=dataFile&p_startYear=&p_c=&p_stn_ num=066062.

Russell, H.C., 1877. Climate of New South Wales: Descriptive Historical and Tabular, NSW Government Printer, p 12–13.

Sydney Morning Herald, 16 Oct 1844 page 2.

Sydney Morning Herald, 18 Oct 1844 page 2.

Sydney Morning Herald, 23 Oct 1844 page 4.

Sydney Morning Herald, 4 May 1845 page 2.

Meet a Member

Clive Robertson

Every issue, an AMOS member is selected at random and sent some questions about who they are and what they do.

This issue we meet Western Australian and foundation member Clive Robertson.

Where does this find you?

This finds me at home.

What do you do?

I am retired — 17 years next month.

A brief summary of my weather service: I started in Melbourne in March 1959, coming from WA. At 18 weeks into the course I, along with a fellow WA member of the course (who went to Daly Waters), were chosen to go out into the field. I was sent to Halls Creek.

The service was short on field staff and wanted two in a hurry to take up field positions. I was one of them. I served at Halls Creek for 12 months, then followed my longest stint, three years at Carnarvon. I then went to Cocos Keeling Island. This posting was followed by broken terms at Guildford, including Onslow, Port Hedland, Geraldton and Albany.

I took long service leave and worked in Britain at the London Weather Office for five months in 1968. I returned to Perth, posted to the Regional Office, with three months as the acting OIC at Esperance. I moved onto my new posting with the Telecommunications Division, later Telstra, in January 1971. I’ve retained an interest in weather

before and since being associated with the Bureau.

Why did you get into it?

I assume that you meant why did I join AMOS? I was an Australian member of the Royal Meteorological Society (RMS) at the time that I joined. I have continued both memberships, of the RMS and of AMOS since. I think that I joined the RMS in 1969 or thereabouts and was a foundation member of AMOS. What is the best thing that you do?

Until recently, into 2010, I was the local treasurer of AMOS. Otherwise I spend much of my day doing the crossword type puzzles in the West Australian and the Australian. These occupy much of my time — a recent stroke has restricted my actions in this capacity but I carry on nevertheless.

What did you want to be when you were 10?

An engine driver. This included driving the woodline engine that I grew up with on the Goldfields.

How do you relax?

Doing the puzzles and an occasional game of golf — play the latter rather poorly now but it is fun.

What is your favourite holiday destination?

Any place that makes it easy to get to and where we can relax.

Significant Mesoscale Oceanography

Autumn 2011 Paul Sandery In this article we look at some interesting observations and analyses of the oceans around Australia for Autumn 2011. As winter approaches, the Leeuwin Current (LC) and the East Australian Current (EAC) retreat to the north, the subtropical convergence (STC) migrates equatorward and the shallow coastal and shelf waters and open ocean surface layers cool. The southern shelf seas begin to produce a spectacular display of currents related to dynamical instabilities along the shelf break. These are characterised by meanders, jets, filaments and eddies that are linked to the sharp fronts which exist between shelf waters and cooler open ocean waters.

Figure 1 shows five-day means of sea-level anomaly (SLA), sea surface temperature (SST) and sea surface salinity from the Bureau of Meteorology ocean forecast system (OceanMAPS) for the period ending 30 May 2011.

In January and February 2011 we saw large SLA and SST anomalies off Western Australia, which have cooled but Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 72

are by and large persisting at present. Since then, however, transport of LC water around Cape Leeuwin has fed the now active South Australian Current (SAC), which has made its way along the shelf break of the Great Australian Bight (GAB) to be close to the western Eyre Peninsular.

In the coming months, this warm flow is expected to continue eastward and bifurcate into Bass Strait and the wintertime Zeehan Current off western Tasmania. Coastal waters across Northern Australia have significantly cooled in the past few months, leading to broad areas of anomalously cool SSTs for this time of year in a narrow band adjacent the coast. Whilst the LC and EAC have retreated, a significant amount of heat content remains at the southern extensions of these current systems.

Particularly noticeable are two anticyclonic warm core eddies present at the moment off Newcastle and Eden (Figure 1, top). Low sea surface salinities in Figure 1 in the Indonesian Throughflow region and in the Timor Sea

represent the contribution of equatorial oceanic water to the South East Indian Ocean, whereas the high salinities in the GAB and South Australian Gulfs reflect a source for the SAC that depends on summertime evaporation.

Ocean colour products are useful for characterising ocean features throughout the year, whereas SST products at times can be less useful because surface gradients can be weak or non-existent, especially in the summer months. Figure 2 shows Moderate Resolution Imaging Spectroradiometer (MODIS) average chlorophyll concentration for March 2011. The field represents integrated near surface concentrations. In open ocean waters this is can be around 20 m whereas in turbid coastal areas it can be around 2–3m. The circled areas highlight anomalously low concentrations in areas of the southern shelf seas compared to climatology.

Autumn climatology (not shown) suggests that the seasonal mean distributions in this period are usually of relatively uniform distribution on the shelf, as in Figure 2 outside the circles. The patterns observed here have persisted through April into May (not shown), yet are breaking down as winter approaches, with average synoptic winds increasing and incoming solar radiation decreasing. The higher mean winds create relatively larger mixing and tend to arrange concentrations into a more uniform distribution over the shelf. These observations suggest surface-layer waters in these anomalously low areas are likely to have been advected from the open ocean, a source well away from the coast.

This would be consistent for Bass Strait, as the distribution here represents the typical advection pattern resulting from mean westerly wind and positive SLA-driven eastward transport on the southern shelf. The latter is a product of steric and non-steric contributions to the SLA. The steric part results from both the transport of warmer waters from the LC into the GAB and seasonal summertime heating and circulation patterns in the GAB and South Australian Gulfs. The non-steric part is largely the sum of the weather band driven coastal trapped wave anomalies that typically create more eastward surges (positive SLA) than westward surges (negative SLA) of the shelf currents at this time of year. High chlorophyll concentrations in coastal regions often indicate more than the presence of chlorophyll, because there are other constituents, such as CDOM (colour dissolved organic matter) and particular sediments that alias in the radiometric spectral band in which chlorophyll is measured. High chlorophyll concentrations in the eastern and south-western Bass Strait entrances are symbolic of the energetic tidal stirring that takes place here.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 73

Figure 1. Five-day means of sea-level anomaly (top), SST(middle) and sea surface salinity (bottom) from OceanMAPS for the period ending 30 May 2011.

Figure 2. MODIS chlorophyll concentration for March 2011. The circled areas highlight anomalously low seasonal levels in shelf waters. Colour is scaled from blue (low) to green (high) to red (very high) concentrations.

Calling all budding young artists: 2011 School Art Competition The atmosphere and the ocean have long been a source of inspiration for artists of all kinds. We invite you to be inspired by them, too!

You are invited to submit a painting, drawing, collage or other type of visual art on the theme of how the weather or the ocean affects people’s lives to the 2011 AMOS Art Competition.

This competition is open to all school students from grades 1 to 10 in Australia.

There are two entry categories: • Primary school (Grades 1 to 6)

• Secondary school (Grades 7 to 10)

The winners of each category will receive a cash prize of $50, and their schools will receive a prize of books for their library.

The closing date for entries is Friday, 4 November 2011.

Entry forms available at www.amos.org.au/education/cid/19/parent/1/t/education.

Each entry must be accompanied by a completed AMOS Art Competition Entry Form and be submitted to the Administrative Officer either by: Email: admin_officer@amos.org.au Post: AMOS, GPO Box 1289, Melbourne, Vic 3001

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 74

Charts from the Past with Blair Trewin

21 July, 1982 The year 1982, which saw the development of one of the strongest El Niño events on record, was one of the most severe drought years in the history of southeastern Australia. Rainfall was well below normal from April onwards, and the winter was especially dry. It was also notably frosty in many parts of the country. June 1982 had the largest negative minimum temperature anomaly (−2.0°C) ever recorded for a month in Australia. July was not far behind, and had the coldest nights on average for any July in most of southeastern Australia, by a full degree for Victoria. It was also the driest July on record for Victoria, and for Australia as a whole.

Probably the most significant of several very notable frost events occurred in the third week of July. Its precursor came when a weak low and front crossed South Australia and Victoria on the 18th and 19th before deepening in the Tasman, producing a very cold southerly airstream on its western flank. The most significant effects were in southern Tasmania and Gippsland, both of which experienced snow to very low levels. Snow fell in Orbost, only 40 m above sea level, for most of the day on the 19th, and the maximum temperature of 5.6°C was clearly the town’s lowest on record. There was also widespread snow near sea level in and around Hobart. Further north, Canberra had its most significant settled snow since 1974, and there were falls above 800 m as far north as the NSW Northern Tablelands.

Despite the snow, the system was a relatively dry one — only in Gippsland did rainfalls widely exceed 10 mm — and very dry air moved over southeastern Australia in the system’s wake as a high pressure ridge developed over the region. This set the scene for a sequence of exceptionally

cold nights, peaking on the 21. Perisher Valley (NSW) dropped to —15.8°C, but the most abnormal temperatures were in Victoria and eastern South Australia.

Perhaps the most exceptional was −7.5°C at Kyabram, the lowest on record for a low-elevation Victorian site. Other all-time record lows included those at Ballarat (−6.0°C), Echuca (−5.5°C), Mildura (−4.0°C), Castlemaine (−6.3°C), Murray Bridge (−5.0°C) and Renmark (−3.8°C).

Melbourne reached −0.8°C, arguably its lowest of the century once the urban heat island is taken into account.

(There has only been one night below 0°C since, in 1984).

There were significant crop losses in northern Victoria.

Conditions were notably cold in other states, but not to quite the same record-breaking extent. Canberra’s −8.6°C was its coldest of the post-1971 period, while Cooma dropped to −11.3°C. In Tasmania the lowest temperature was −10.2°C at Shannon.

Further west, a low-pressure trough produced hailstorms in the Perth area on the 20th, with some lightning damage, although rainfall totals were generally modest, being mostly less than 20 mm with a peak of 32.2 mm at Henley Park.

The abnormal cold changed to abnormal day-time warmth during the second half of August. This led to an exceptional winter heatwave over most of the same areas affected by the July cold outbreak, and extreme heat was a regular feature through the following few months.

Synoptic chart for 0000 UTC (1000 AEST), 21 July 1982.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 75

Calendar

2011

symposium on “The Future of Operational Oceanography”, Hamburg, Germany.

July

November

11–14 11th Global Conference on Global Warming, Lisbon, Portugal.

August 1–4 14th Conference on Mesoscale Processes, Los Angeles, USA.

September 4–9 10th International NCCR Climate Summer School: “Climate Change, Extremes and Ecosystem Services”, Grindelwald, Switzerland.

12–16 11th European Meteorological Society Annual Meeting, Berlin, Germany.

19–21 19th International Conference on Modelling, Monitoring and Management of Air Pollution, Malta.

October 4–8 10th WMO Conference on Weather Modification, Bali, Indonesia.

22–29 DISCCRS VI Interdisciplinary Climate Change Research Symposium for early-careers scientists, Colorado Springs, USA. 24–28 World Climate Research Program Open Science Conference: Climate Research in Service to Society, Denver, USA. 25–27 Federal Maritime and Hydrographic Agency

7–10 2011 IYC O3: Symposium on Stratospheric Ozone and Climate Change, Washington, USA. 8–11 The International Conference Energy Meteorology (ICEM), Gold Coast, Queensland.

and

December 1–7 5th International Verification Methods Workshop, Melbourne.

4–8 International Congress of Biometeorology, Auckland, New Zealand.

5–9 AGU Fall Meeting, San Fransico, USA. 12–16 International Congress on Modelling and Simulation (MODSIM), Perth.

2012 January 31–3 Feb AMOS 2012 Conference: Connections in the Climate System, Sydney.

February 20–24 2012 Ocean Sciences Meeting, Salt Lake City, USA.

April 23–27 10 ISCHMO, Nouméa, New Caledonia.

Australian Meteorological and Oceanographic Journal

Articles — Vol 61 No. 2, June 2011 Risbey, McIntosh and Pook. Evaluation of rainfall drivers and teleconnections in an ACCESS AMIP run Kuleshov, Hettrick, Mackerras, Darveniza and Jayaratne. Occurrence of positive and negative polarity cloud-to-cloud lighting flashes: case study for Brisbane, Australia Nicholls and Larsen. Impact of drought on temperature extremes in Melbourne, Australia Le Marshall, Seecamp , Xiao, Steinle, Sims, Skinner , Jung and Le. The Generation and Assimilation of Continuous AMVs with 4DVar

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 76

Regular features: Ganter. Seasonal climate summary southern hemisphere (winter 2010): A fast developing La Niña Wu. Quarterly Numerical Weather Prediction Model Performance Summaries – October to December 2010 and January to March 2011 Book review: Hess. Turbulence in the Atmosphere.

2011 AMOS Council Executive

President Vice-President Secretary Treasurer Past President

Neville Nicholls Blair Trewin Damien Irving Ian Watterson Richard Wardle

Ordinary Members John Allen Stewart Allen Steven Phipps Robin Roberston Sandra Schuster Perry Wiles

03-8344 9596 03-9669 4341 02-9385 8957 02-6268 8289 02-9272 8025 03-9669 4664

AMOS Administrative Officer

Jeanette Dargaville GPO Box 1289, Melbourne VIC 3001 Phone 0404 471 143 (attn: AMOS admin officer) E-mail: admin_officer@amos.org.au

03-9902 0111 03-9669 4623 03-9239 4685 03-9239 4544 03-9905 4411

Sub-Committee Convenors Public Relations Awards Conferences Education

Centre Chairs Sydney Hobart Melbourne Canberra Perth Darwin Brisbane Adelaide

Michael Pook Mark Williams Val Jemmeson Phillip Riley

03-6232 5228 03-9669 4968 03-9669 4095 03-9669 4530

Angela Maharaj Kelvin Michael Vaughan Barras Margi Bรถhm Merv Lynch Hakeem Shaik Hamish McGowan Caecilia Ewenz

02-9850 8357 03-6226 2977 03-9669 4045 02-6268 8749 08-9266 7540 08-8920 3814 07-3365 6651 08-8366 2723

Representatives AMM FASTS

Kathy McInnes Steven Phipps

03-9239 4569 02-9385 8957

AMOS is represented on the relevant Australian Academy of Science committees.

2011 Bulletin of the Australian Meteorological and Oceanographic Society ISSN 1035-6576

Editor

Linden Ashcroft School of Earth Sciences The University of Melbourne VIC 3010 Phone: 03-8344 7672 Fax: 03-8344 7761 Email: l.ashcroft@student.unimelb.edu.au

Editor-in-chief

Stewart Allen Email: Stewart.Allen@bom.gov.au

Assistant Editors Diana Greenslade Blair Trewin Andrew Watkins

Regional Sub-editors Michael Hewson (Brisbane) Caecilia Ewenz (Adelaide) Damien Irving (Melbourne) Sandra Schuster (Sydney)

Contributors Blair Trewin Gary Brassington Paul Sandery Andy Thomas

Advertising Manager Please contact the Admin. Officer.

Publisher

AMOS, GPO Box 1289, Melbourne VIC 3001, Australia

Contributed articles, news, announcements and correspondence for the Bulletin should be sent to the editor no later than 15 July, 2011. They will be reviewed and the galley proofs returned to the author if requested. An ASCII version of the text is required via e-mail or digital media to minimise typographic errors.

The Bulletin of the Australian Meteorological and Oceanographic Society is produced and distributed with the assistance of CSIRO Marine and Atmospheric Research and the Bureau of Meteorology.

AMOS Website: www.amos.org.au