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AustralianMeteorological & OceanographicSociety

Bulletin of the Australian Meteorological & Oceanographic Society Vol 24, No.6, December 2011 ISSN 1035-6576


Contents Editorial ....................................................................................................................................................................... 113 President’s Column ..................................................................................................................................................... 113 News ........................................................................................................................................................................... 115 News from the Centres ............................................................................................................................................... 115 Conference report ....................................................................................................................................................... 119 Obituary — Dean Collins .......................................................................................................................................... 121 Review — Tornado Alley 3D ..................................................................................................................................... 122 Articles ........................................................................................................................................................................ 123 A.Werner and N.J.Holbrook — 2011/12 Experimental Tropical Cyclone season forecast for the Australian region using a new Bayesian regression model ..............................................................................................................................123 J.Bye — A note on climatonomy ........................................................................................................................................126 A.Pezza — A note on John Bye, one of our prominent members .....................................................................................126

Meet a Member .......................................................................................................................................................... 127 Snapshot ..................................................................................................................................................................... 128 Significant Mesoscale Oceanography ........................................................................................................................ 129 Charts from the Past with Blair Trewin ....................................................................................................................... 131

ISSN 1035-6576 Cover picture: A storm front approaches Melbourne on 9 November 2011, from Parkville (top) and South Yarra (bottom). For more great photos taken by AMOS members, turn to page 128. Images: AMOS members Mohammad Hassim and Nicholas Tyrrell. 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.


Editorial

End of year congratulations Already we find ourselves at the end of 2011, and the last AMOS Bulletin for the year. But don’t despair, there are exciting things on the horizon. The biggest upcoming event, apart from Christms and the the Boxing Day test of course, is the 2012 AMOS conference. The Sydney conference is shaping up to be one of the biggest yet, with almost 350 abstracts submitted and three parallel sessions confirmed for each day. Make sure you register for the conference and the conference dinner (at Luna Park!) to avoid missing out. This is a time of year not only for celebrations, but also congratulations. A big congratulations fi rstly to Joseph Kidston and Jason Evans, two AMOS members from the UNSW Climate Change Research Centre (CCRC) who have recently had success with the Australian Research Council (ARC). Joe Kidston has been awarded a Discovery Early Career Research Award (DECRA) to conduct work on the poleward shift of jet streams and storm tracks in climate change models. DECRA funding is given to excellent early career researchers, and was awarded to only 277 scientists in this, its first year. Dr Kidston was the only recipient in the Atmospheric Science research field. Jason Evans — who is also convening next year’s conference — has received a Future Fellowship to conduct research on how climate change will influence sub-daily rainfall patterns. Future Fellowships were awarded to just over 200 mid-career scientists across Australia, to promote research in areas of critical national importance. Just like Joe, Dr Evans was the only person to receive a Future Fellowship for Atmospheric Research. Well done to both of them and all other AMOS members who were successful in their ARC applications. Congratulations also to the 2009/2010 Uwe Radok Award winner, Jan Zika. The Uwe Radok award, you may remember, is given to the best PhD thesis in atmospheric or oceanic science for the year.

Jan gained his Bachelors degree in Physics and Mathematics from the University of Tasmania with honours in Astrophysics in 2005. He went on to complete a PhD in Oceanography and Climate Science through UNSW and the CSIRO Marine and Atmospheric labs in Hobart. His PhD research developed a new framework for understanding the role of mixing in the ocean, and was published in several papers. After his PhD Jan undertook a postgraduate fellowship at the Laboratoire des Écoulements Géophysiques et Industriels in France from 2009–2011. He is currently a postdoctoral fellow at UNSW’s CCRC, but in 2012 will travel to the University of Southampton, UK, to take up a National Environment Research Council (NERC) Fellowship. It will be great to hear him present his work at the AMOS Conference next year. Finally, a big congratulations and thank you to everyone who has contributed to the Bulletin over the past 12 months. Your articles, conference reports, photos and Meet a Member responses have made the Bulletin what it is. Please keep them coming, and don’t hesitate to contact me if you have any suggestions or comments. Dr Alex Pezza has done just that for this issue, suggesting a semiregular section honouring our more prominent members. He contributed the first piece in this series on his colleague and friend, Dr John Bye. If you would like to become more involved in the Bulletin, we would love to hear from you, as the position of Editor is now open. Wishing you a safe and happy holiday period. Don’t forget to visit the conference website at www.amos. org.au/2012conference

Linden Ashcroft

President’s Column

The Intergovernmental Panel on Climate Change (IPCC) Special Report on Managing the Risks of Extreme Events and Disasters to advance Climate Change Adaptation (also known as “SREX”) The Summary for Policymakers (SPM) of the SREX was released on Friday 18 November. It was approved, sentenceby-sentence and by consensus (ie with no dissenting Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 113

delegations) by delegates from the 194 countries that are members of the IPCC at a recent meeting in Kambala, Uganda. I was among them.


The SPM has had some media coverage since its release. But it is clear that many people do not understand how the IPCC prepares its reports and assessments. So I thought I should provide some details of the preparation of the SREX. SREX consists of nine chapters prepared by separate author teams, plus an SPM prepared by representatives of these chapter teams. I was one of the two Coordinating Lead Authors (CLA) of Chapter 3, “Changes in Climate Extremes and Their Impacts on the Natural Physical Environment”. Sonia Seneviratne from ETH in Switzerland was the other CLA. We also had 12 Lead Authors (LAs) and 28 Contributing Authors (CAs) involved in writing the chapter. The 12 Lead Authors came from Argentina, Australia, Brazil, Canada, China, Germany, Iran, Japan, Norway, UK, and USA. All members of the author team had published peer-reviewed scientific papers on climate and weather extremes. Work started in late 2009. We had four meetings of the author team, in Panama City, Geneva, Hanoi, and the Gold Coast, but most of the work was done through email. The fi nal version of the Chapter is over 70,000 words plus about 900 references. Because there has been some criticism of the IPCC for using “grey” literature we limited our sources almost entirely to the peer-reviewed literature. There were four rounds of review: an informal review, an expert review, a combined expert/government review, and fi nally a second government review (the last of these focused solely on the SPM). We received, over the four rounds of review, about 5000 review comments on Chapter 3 material. We had to document our response to every review comment, and indicate what changes we made in response to the review. There were two Review Editors (from Russia and Argentina), also experts in weather and climate extremes, who had to check if we were responding appropriately and if we had made the changes we indicated we would. Eventually all the review comments, plus our responses, will be available publically. The IPCC will never win the Nobel Prize for Literature. An international writing team of 14 scientists is not conducive to the preparation of stylish prose. As well, a very formal process of assessing possible changes in a specific extreme was applied throughout the SREX. So the text is littered with terms such as “likely”, and “low confidence”, each of which has a specific meaning. The Executive Summary of Chapter 3 uses these terms more than 50 times, in about two pages of text. This makes the Chapter, I have to admit, a rather boring read.

After the Chapters were written, a selection of the most important statements from the nine chapters was combined into the SPM. The approval process carried out in Kampala aims to ensure that the SPM delivers a clear message that can be understood by the target audience (ie to improve the clarity of the scientists’ writing). However, no changes can be made to the SPM that do not reflect the science in the underlying Chapters. So the CLAs are at the approval meeting to ensure that the fi nal version of the SPM is consistent with the Chapters. The approval meeting can also request that the selection of statements included in the SPM from the Chapters be changed, as long as such changes do not result in the SPM being inconsistent with the Chapters. The writing process is much tougher than would be the case if a small number of scientists were writing a book for a commercial publisher, because of the large writing team, the need to apply very formal assessment language, the need to restrict sources to the peer-reviewed literature, the rigid deadlines, the requirement to respond in writing to thousands of review comments from hundreds of reviewers, and the recognition that even a single typo will leave the IPCC (and the authors) open to abuse and attack. It is a challenge — and it is a relief to complete the task and return to the simpler task of writing and publishing scientific papers in the peer-reviewed literature. SREX is the fourth IPCC assessment/report for which I have been either a CLA or LA. Each has been more timeconsuming and challenging than the last. Many of my weekends, most evenings, and every vacation over the past two years have been disrupted by SREX work. As is the case with most IPCC authors I received no payment for the work. I have had to fit it around my “day job”. It will have no effect whatsoever on my career, and it has taken me to places I never wanted to visit. So why do it? I see IPCC as a duty and a challenge. I have been a climate researcher for 40 years, and it is my responsibility to communicate climate science so that politicians and others can base their decisions on the science, rather than on the opinion of a radio shock-jock or journalist. And I see it as a challenge to produce a document that accurately assesses the literature, in a consensus with my 13 co-authors. The SREX SPM is available now from the IPCC web site; the underlying chapters are being copy-edited and will be available in February. The SREX SPM can be found at www.ipcc-wg2.gov/SREX/.

Neville Nicholls

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 114


News

Calls for nominations for the AMOS National Council Damien Irving

AMOS Secretary Address for nominations and correspondence: damien.irving@csiro.au The AMOS National Council consists of the four officers of the Society (President, Vice-President, Treasurer, Secretary), six “ordinary” members, the immediate past President, and the Chairs of each Regional Centre and Special Interest Group. As well, the Chairs of Committees attend Council meetings. The officers and ordinary members of Council are elected for two year terms, at the Annual General Meeting (AGM) usually held in conjunction with the AMOS Annual Conference. The terms of each of the ten elected members of Council, excepting my own term as Secretary, conclude at the AGM to be held in conjunction with the 2012 annual conference in Sydney. As such, we hereby call for nominations for each of the elected Council positions (except Secretary), for the next two years. Nominations shall be made in writing, signed by two eligible members of the Society and accompanied by written consent of the candidate. The nomination must be delivered to the Secretary (via the AMOS Administration Officer) by 31 December 2011. Visit the link at the end of this article to downloadthe 2012 Nomination Form.

The list of nominees will be distributed to all members with the notice of the AGM (which must be done at least 21 days prior to the AGM). All current members of Council (except the President and Vice-President, who are both elected for two year terms) can re-nominate for their current positions. The Vice-President is expected to nominate for President*. Please contact a member of Council if you wish to nominate but are unable to locate two other members to assist with your nomination. *Note that, traditionally, the Vice-President serves for two years and is then elected unopposed as President. Nomination for Vice-President is taken to indicate willingness on the part of the nominee to serve as President for the two years following their term as Vice-President. For more information, visit www.amos.org.au/aboutus. Nomination forms can be downloaded at www.amos.org. au/news/id/138.

News from the Centres

Priestley Cup 2011 Reza Amiri

Monash University Team Captain On the 21th of November 2011 Melbourne witnessed the 13th annual Priestley Cup football tournament. Similar to the previous year, the tournament was held at the Albert Park Futsal Centre. The two courts provided a cosy atmosphere for the players and the spectators supporting their respective teams. Teams arrived on the court on time, pulled up their long socks and warmed up for the event. The reigning champions, the Bureau of Meteorology came to defend their cup after two successive championships. The University of Melbourne, runner-up of the previous season were ready to make their way to fi rst place, and the Monash University squad came determined to prove that they could repeat their previous title victory in 2005. CSIRO was quite content to be out of their beachside office in Aspendale, have a few beers and play some friendly indoor football.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 115

The first round started with two simultaneous matches — on court one, the Bureau took on Monash. The previous encounter between these teams ended in a draw last year, but things were different this year and Monash had ball control for most of the match. Th is phenomenal control from their midfield resulted in plenty of scoring opportunities for their strikers. Although most of their shots whizzed way outside the reach of the Bureau goalkeeper, 6 of the shots managed to fi nd their way into the net. The Bureau did its best to return the favour, succeeding in responding to one of the goals. Much rejoicing took place for the Bureau. The fi nal score of 6–1 was a big surprise to the champions of the two previous seasons. On court number two, Melbourne Uni and CSIRO played a close fought game with plenty of scoring opportunities for both teams, but in the end it was Melbourne who made the most of its chances by scoring 6 goals while CSIRO scored 3.


Melbourne battle it out against Monash. .

The Bureau of Meteorology defend a CSIRO attack.

The second round was decisive as the two winners and two losers had a face-off. The fi erce rivalry between Monash Uni and Melbourne Uni added an extra element to the game and was set to continue (they don’t really have a fierce rivalry, I just made that up).

chance at winning the cup. Both Melbourne and CSIRO approached their matches in the hope that CSIRO would crush Monash by a respectable goal margin and run away with the cup. Alas, it was not to be their day as Monash repeated the result of the first game with a 6–1 win over CSIRO. The tournament ended with a Monash victory, and much rejoicing took place. After more than half a decade, the trophy would call Monash home again.

The two teams seemed to be of equal strength given their comfortable victories in the fi rst round. It was Monash who struck twice in the early stages of the game, however Melbourne composed quickly and responded with two of their own goals. Monash added another goal late in the half to take the lead, 3–2. The beginning of the second half saw both teams taking a different tactical approach. Monash took a defensive position and relied on counterattacks, whereas Melbourne started the second half very aggressive, and threatened the Monash defence and goalkeeper multiple times. Th roughout the second half, Melbourne continued to push relentlessly to fi nd the equaliser, but an impenetrable wall protected the goals of Monash. The second half didn’t bring any new goals and the game ended in 3–2. On the other court, the CSIRO and the Bureau encounter attracted a lot of attention as the winner of this match also had a shot for the coveted Priestley cup. Unfortunately for the Bureau, the red curtains closed on them and the game ended in CSIRO’s favour, 6–1.

The tournament created a lot of breathtaking matches, plenty of goals and excitement for the participants and spectators. After the game, everyone came together to celebrate the occasion that brings the four institutions together by once again rejoicing, eating pizza and drinking beer. Special thanks Blair Trewin, Frank Drost, Vaughan Barras and all at the Melbourne Centre who made it once again a terrific day.

Results:

After the second round, Monash, Melbourne and CSIRO had collected 6, 3 and 3 points respectively, and the Bureau had 0 points. The final round started after a short break of orange injections, with three teams having a

Monash vs Bureau

6–1

Melbourne vs CSIRO

6–3

Melbourne vs Monash

2–3

CSIRO vs Bureau

6–1

Melbourne vs Bureau

4–3

Monash vs CSIRO

6–1

The final ladder Team

Win

Draw

Loss

For

Against

Points

Monash

3

0

0

15

4

9

Melbourne

2

0

1

12

9

6

CSIRO

1

0

2

10

13

3

Beauru

0

0

3

5

16

0

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 116


The victorious Team Monash University

The official trophy ceremony

Team University of Melbourne

Team Bureau of Meteorology

Team CSIRO. Photos kindly taken by Damien Irving.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 117


Melbourne Centre update Damien Irving

Melbourne Centre Address for correspondence: damien.irving@csiro.au It has been another successful year for the AMOS Melbourne Centre. Building on the good work of previous years, we have continued to organise prominent events for both those working professionally in the atmospheric and oceanic sciences and the general public. Major events of 2011 included: t

Public symposium: The recent extreme weather: a scientific perspective. David Karoly, Neville Nicholls, Karl Braganza

t

Pearman lecture: Recent changes in the climate of the polar regions. Ian Simmonds

t

CAWCR science tea: MODIS imagery in Bureau operations. Bodo Zeschke, Christopher Down

t

Movie night: How I ended last summer

t

Guest seminar: Warnings from the Japan earthquake. Stewart Allen, Jim Fraser

t

Guest seminar: Polar ozone loss in the climate system. Markus Rex

t

Movie night: Tornado alley 3D

t

Careers night: Monash University

t

7th annual weather tipping competition

t

13th annual Priestley Cup soccer tournament

A big thank you to the 2011 committee for their efforts in making these events possible. In particular, outgoing Chair Vaughan Barras should be congratulated for his tireless dedication to Melbourne Centre activities over the past two years. To formally conclude 2011, the AMOS Melbourne Centre held its Annual General Meeting (AGM) on Thursday 10 November at the Bureau of Meteorology. Prior to the meeting, attendees were treated to a lecture from former Priestley Medal winner Professor Peter Rayner, who has recently returned to the University of Melbourne after spending time with Princeton University in the USA and the Laboratory for the Science of Climate and Environment in France. Professor Rayner spoke on the challenges of measuring and interpreting atmospheric carbon dioxide and recent advances in the field. The following committee was elected for 2012 at the AGM: Damien Irving (Chair); Frank Drost (Secretary); Mitchell Black (Treasurer); Luke Hande, Nicholas Tyrrell and Vaughan Barras (ordinary members). Given that this is a smaller committee than previous years, anyone who would like to either join the committee as an ordinary member or contribute to organising a specific event should contact Frank (fdrost@unimelb.edu.au) or Damien (damien.irving@csiro.au).

AMOS abroad: six months in a leaky Boulder Michael Hewson

Vice-chair and secretary, Queensland Centre AMOS member and PhD student, Michael Hewson, was fortunate to spend the fi rst six months of 2011 visiting the National Oceanic and Atmospheric Agency (NOAA) in the USA. His purpose, at the David Skaggs Research Centre in Boulder Colorado, was to learn the chemistry transport version of the Weather Research and Forecasting model (WRF-Chem). Dr Georg Grell and Dr Steve Peckham were fi ne teachers and amiable hosts. Michael is affiliated with the Climate Research Group (School of Geography, Planning and Environmental Management) at The University of Queensland. Boulder is a town the size of Cairns, and it exists for the University of Colorado, several centres of atmospheric research, and high technology industry (including companies supporting meteorological satellite remote sensing). Despite its size, Boulder is the sort of place that supports two orchestras as well as the famous e-town radio program (for those up on US music). Even better, Boulder is nestled up against the foothills of the Rocky Mountains and has all the outdoor adventure you could want. Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 118

Michael Hewson (left) with Dr Steve Peckham on the rooftop of the David Skaggs Research Centre in Colorado. Image: Will von Dauster.


Meteorologists at the laboratory weather briefing debated whether the 2010/11 La Niña winter brought record snow falls to Colorado. Certainly, skiing on 80 inches of snow base at the local Eldora ski facility (a $5 public bus fare from Boulder) makes for a remarkable experience. WRF-Chem is gaining a respected following for modelling atmospheric constituent transport, and research continues into a raft of new functions. As a geographer, Michael needed to know how to operate the model, and found plenty of challenges associated with the ingestion of global emission datasets, the computing power needed to run the model and the complexity of Fortran name-lists to set up an extraordinary number of atmospheric physics and chemistry variables, as well as the operational complexity needed to improve aerosol optical depth modelling with the assimilation of satellite images. The WRF tutorial (held twice a year) and the WRF-Chem tutorial (held in conjunction with the summer WRF course) is extremely valuable — even if one National Centre for Atmospheric Research (NCAR) staff member lectures with a banjo.

Dr David Gill “lecturing” at the NCAR February 2011 WRF course. Image: Michael Hewson.

NOAA David Skaggs Research Centre Boulder CO USA. Image: Michael Hewson.

Conference report

International Conference on Energy and Meteorology 8–11 November, 2011, Gold Coast Robert Huva with Roger Dargaville

School of Earth Sciences, University of Melbourne and Melbourne Energy Institute It was Sunday afternoon on November 6 and I had arrived for the inaugural International Conference Energy and Meteorology (ICEM). Amid the seemingly disproportionate number of young families with screaming children, I decided to head for a walk along the Surfers Paradise beach — I had just enough time (despite the lack of Daylight Savings Time) to catch the sunset in between the ever-increasing density of high-rise buildings that line the shore. Fortunately the forecast for the week was stunning with 28°C and clear skies expected every day. The stage was set for a very good week. The theme of the conference was the interaction between weather, climate and energy, in particular renewable energy. Weather is the largest driver of variability in electrical energy demand. Emissions from fossil fuel energy are the main driver behind global climate change. And the output of renewable energy technologies including wind turbines, solar photovoltaics, concentrating solar thermal, wave power and even hydro and biomass are impacted by short and long term variability in weather. Understanding these synergies is key to building the energy system of the future, and it makes sense to combine these topics into one week-long conference on Australia’s sunny coast.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 119

Monday was the pre-conference seminar and the venue, the Marriott, was only a short walk from my hotel. The day served as a good overview of the themes for the conference and provided an early chance to network. Drinks following the last talk were also an effective icebreaker, while the first instalment of the unofficial “dinner train” that ended up weaving its way from the Marriott to the eateries on Cavill Avenue each evening began later that day too. Tuesday was the start of the conference proper and began with a welcome from the organiser, Alberto Troccoli of CSIRO. He was followed by the first talk from Subho Banerjee of the Department of Climate Change and Energy Efficiency — fitting given that the Clean Energy Future legislation was passed through the lower house as he spoke. After morning tea — and coffee number three for the day — Neil Plummer (Bureau of Meteorology) and John Zillman (University of Melbourne) provided useful overviews of the national and international weather and climate monitoring networks and the long relationship between weather and energy. The fi rst instalment of the parallel sessions started after lunch and despite the plethora of interesting talks I soon came to the realisation that switching between rooms to sample all of the topics on


offer was unfortunately not feasible. Afternoon tea came and went quickly and before I knew it the final session of day one was upon us; and boy did it deliver! John Dutton of Prescient Weather Ltd. gave a comprehensive talk and somehow managed to summarise a lot of the conference with his catch-phrase “Expect the mean; Hedge the extreme and use the forecast to go in between”. Ralph Sims of Massey University followed and had us all in fits of laughter with his take on renewable energy and climate change mitigation. Wednesday started well with Roberto Schaeffer from the Federal University of Rio de Janeiro showing the potential negative impacts of climate change on Brazil’s hydro power industry (which supplies 85% of Brazil’s electricity!) followed by V.V.N Kishore from TERI University in New Dehli, who gave examples of how India plans to invest in both distributed generation (rooftop photovoltaic) and large-scale solar. During the parallel talks Sue Haupt of NCAR illustrated how they combine deterministic forecasting with a 30-member ensemble, statistical learning and nowcasting to better forecast wind power output through central USA (particularly during “ramp” events). After lunch we had the first of our panel sessions, which was an enjoyable format that touched on issues like data paucity around the world and the role of intellectual property rights in limiting access to valuable data. The second panel session was following afternoon tea and was also interesting in its discussion of how to better educate the next generation of students in both energy and meteorology. Thursday morning had compelling talks from David Renne of the National Renewable Energy Laboratory (NREL) who touched on NREL’s wind and solar integration study, and Peter Coppin of CSIRO who demonstrated the value of short-term storage in dealing with renewable energy variability. The afternoon sessions had valuable insights from Tim George of the Australian Electricity Market Operator (AEMO) who showed that AEMO’s wind forecasting of the eastern states can be accurate to within 4% at one hour ahead. Mathew Wright of Beyond Zero Emissions also gave an inspiring speech highlighting that 100% reliance on renewable energy in Australia is not a matter of insufficient technology, but more a matter of insufficient policy. Thursday evening was the conference dinner, also at the Marriott, and the pre-dinner drinks

ensured the air was buzzing with discussion over the first two courses. In between courses Alberto Troccoli gave his recollection of how the idea for the conference came about during a long shower and we got another interesting talk from John Dutton about how meteorology affects aviation, which included an almost unbelievable video of Boeing 777s landing in severe cross-winds. Friday was the last day of the conference and was jampacked in the morning with an Australian Solar Institute workshop running alongside the normal conference format of plenary session plus parallel session. The plenary session focused on the challenges for developing countries with Mersie Ejigu from Uganda and Pierre Audinet from the World Bank giving absorbing talks. In the final session following lunch, Andre Martin of the reinsurer Swiss Re and Keith Parks of Excel Energy Services Inc. provided a change of pace and a new perspective on risk management and the value of having accurate wind forecasts. The conference ended with Alberto Troccoli giving the closing talk and awarding the prizes for best talk (Sue Haupt of NCAR), best student talk (Annette Hirsch of CSIRO) and best poster (Robert Davey of CSIRO). As the final dinner train made its way to Cavill Avenue on Friday evening, I was able to reflect upon what was a very successful conference. Alberto gave a hint that in two years time there might be another instalment of ICEM —if that is the case, I look forward to attending that conference as well.

The view from the poster session at ICEM: the pool at the Marriott.

Wanted: New AMOS Bulletin editor Do you like writing and communicating? Do you want to meet more AMOS members, and work with leaders in our scientific community? Well this is the opportunity for you! AMOS is currently searching for someone to fill the role of Bulletin editor from 2012. The editor is responsible for all aspects of the Bulletin, including writing the editorial, organising the reviews of submitted scientific articles, and collecting and compiling the contents for each issue. There will be support from the current editor, the editor-in-chief and AMOS administrative officer. Some knowledge of Adobe InDesign is helpful, but not necessary. Postgraduate students are encouraged to apply and, if successful, will be financially supported by an honourarium. If you are interested, have any questions or would like to apply, please contact Linden Ashcroft (current editor, l.ashcroft@student.unimelb.edu.au), Stewart Allen (Editor in Chief, stewart.allen@bom.gov.au) or Jeanette Dargaville (administrative officer, admin_officer@amos.org.au). Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 120


Obituary

Dean Collins 4 January 1969–9 November 2011 Andrew Watkins and David Jones Dean Andrew Collins will be well known to many AMOS members, particularly through his engagement in the field of climate change. Sadly, Dean lost his year-long battle with cancer in early November 2011. Dean’s professional passion for meteorology, and climate change in particular, date back to the early 1990s when he completed an Honours and then Masters degree at the Centre for Dynamical Meteorology and Oceanography, Monash University, investigating greenhouse climate change simulations. He changed course, albeit briefly, when he joined the Bureau of Meteorology as a trainee weather forecaster, graduating from the Bureau’s Meteorologist course in late 1995. A brief stint followed “on the bench”, weather forecasting at the Victorian Regional Office, before Dean’s passion for climate overcame him and he transferred to the Climate Analysis Section (CAS) of the Bureau’s National Climate Centre in 1996. Recognising Dean’s talent and passion, he soon took up a role as Senior Climatologist in charge of climate change analysis in CAS. In this role he brought to the fore his skills in the careful science, curation and quality control of Australian climate data. Through this work Dean made an enormous contribution to Australia’s monitoring and understanding of climate change, most notably through his development of the Bureau’s “climate tracker” website1. Th is involved generating Australian (and global) statistics on the annual, seasonal and monthly values for a range of variables — everything from mean temperature to evaporation to ocean temperatures and even density of highs and lows — and creating graphs and maps that have become the backbone of Australia’s understanding of its changing climate. The work led to a sequence of science papers in which the development of “climate change datasets” and the variability and change they described was carefully explained. Every year for Dean culminated in a flurry of activity come January 1, generating a suite of statistics to help put Australia’s climate for the past year into perspective. This work alone has been quoted by everyone from the man in the street to million-reader newspapers to the Prime Minister on the floor of parliament. Dean’s work on climate extremes was also his passion, and again he developed a website showing 30 indices for Australia, based upon the World Meteorological Organization’s Expert Team on Climate Change Detection, 1

www.bom.gov.au/climate/change/

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 121

Dean Collins with a Stevenson Screen at a PCCSP workshop in Vanuatu, October 2009. Monitoring and Indices2. This work is arguably his best, as many believe the significant impacts of climate change will be viewed first through changes in extremes rather than changes in averages; by way of analogy, does the sandcastle get knocked over by the tide or by the waves? Again, this work has formed the basis for numerous reports and has informed a huge range of stakeholders about how our climate is changing. After a dozen years in this role, Dean identified the South Pacific as a vulnerable area where, again, his skills and passion could make a difference. In 2010 he joined the Pacific Climate Change Science Program (PCCSP), where he led a project to improve climate change monitoring and detection in Pacific Island countries. Th is included working closely with staff from 15 National Meteorological and Hydrological Services, many of whom quickly warmed to not only his vast knowledge, enthusiasm, and commitment to make a difference, but also his incredibly dry wit. In total, and despite spending much of his career working with end users and the delivery of climate change services, Dean published over 20 scientific papers on climate change, presented numerous talks at national and international conferences, and contributed to a wide range of climate www.bom.gov.au/cgi-bin/climate/change/ extremes/trendmaps.cgi 2


change education material for general audiences. Th is passion extended to giving talks to community, school and special interest groups, as well as training as a Climate Change Ambassador. Apart from his climate work, Dean also had a love of his family, travel in all parts of the globe, and the Essendon Bombers. At times he even managed to combine these with his vocation — arguably best demonstrated by his huddling around a crackling car radio listening to muffled details of an Essendon preliminary fi nal with fellow Bomber fan Blair Trewin, while deep in the wilds of Litchfield National Park (Northern Territory) postAustralia and New Zealand Climate Conference. While Dean visited many corners of the globe for both work

and play, he took greatest pride in his family’s “Big Trip” — taking his long service leave and camping their way through central Australia, down the West Australian coast and home across the Nullarbor. In typical Dean style, he only quietly revealed details over the course of the next couple of years. Dean’s loyalty, commitment, enthusiasm and wonderfully dry sense of humour will be missed by all those who had the genuine pleasure to know him. Dean is survived by his wife Karola, son Angus and daughter Lily. In lieu of flowers, Dean asked for donations to be made to the Climate Institute (www.climateinstitute.org.au/).

Film Review

Tornado Alley 3D: an authentic storm chasing experience Ailie Gallant Everyone loves a good storm. Rolling thunder, a spectacular light show and fat drops of rain that make the earth smell like summer. Although thunderstorms are far more belligerent than your average cloud, for most of us they simply provide a bit of extra excitement during our day and make the commute home a soggy affair. But in the Great Plains of the United States, known as Tornado Alley, there is a darker breed of storm, one that truly deserves the title “a force of nature”. These intense storms, called supercells, can turn day to night, produce blinding rain and hurl hailstones larger than cricket balls at speeds that would put most fast bowlers to shame. But it is a supercell’s final act that is the most aggressive — the tornado. Although the number fluctuates, the United States generally records over 1000 tornadoes per year. More than 90% of the tornadoes reported are small, perhaps strong enough to rip a few branches off trees and the roof off a shed. The remainder (about 10 to 100 per year) cause the most destruction, knocking down houses and in some extreme cases, ripping up their concrete foundations. Violent tornadoes are responsible for an average of 60 deaths per year in the United States. Tornadoes are both beautiful and destructive. These dichotomous themes are ever-present throughout the film Tornado Alley 3D (which you can see at IMAX cinemas). The movie follows two teams of storm chasers over the course of a spring “chase season”. This is when supercells are most common in Tornado Alley. Their pursuit of tornado-bearing supercells, the motivations of each team and, of course, the spectacular footage dominates the film. Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 122

If you’re looking to find out a little more than the basics of the science behind these storms, this isn’t the film for you. If, however, you want to get up close and personal to a tornado, this is the closest you’ll get without actually being there. The movie’s fi rst story follows 100-plus scientific researchers collecting data. They want to know why some supercells produce tornadoes and others do not. Although meteorologists mostly understand how supercells work, the exact cause of tornadoes continues to elude them. Importantly, a better understanding of tornadogenesis will lead directly to improved tornado warning times. These are currently only a few minutes at most. The second story follows amateur stormchaser (and filmmaker) Sean Casey on a personal quest. Casey is addicted to tornadoes. For the past eight years, he has been on a mission to film a tornado from the inside. In his backyard operation, Casey has constructed a purpose-built “tank” called the “Tornado Intercept Vehicle”. It weighs 7.5 tonnes, is covered in bulletproof glass and ¼ inch thick steel plating, and includes hydraulic skirts and claws that anchor it to the ground. At times it makes you feel like you’re watching Mad Max rather than IMAX. But if you’re expecting this film to be an all-action-packed real-life version of the 1996 Hollywood blockbuster Twister, you’ll be disappointed (although it is narrated by Twister’s leading man, Bill Paxton). In reality, storm chasing is an incredibly tricky business. From my personal experience of two chase seasons in Tornado Alley, you can spend days waiting for the right


atmospheric conditions to produce a supercell. Even when the conditions look right, there’s no guarantee that a storm will occur. Once, I drove over four hours, one way, and saw nothing but a few wispy clouds. When supercells eventually form, chasers have to choose between several storms that may be hundreds of miles apart. I once followed a supercell for six hours and it did not produce a single tornado. At the same time, my friends chased another storm less than 100 miles (160 kms) away and saw six. The film portrayed the true experience of storm chasing wonderfully and once the chase teams were following a tornadic supercell, the IMAX format and 3D came into its own. The adrenaline you feel when seeing a tornado up close is conveyed in vivid detail. In particular, the focus on Casey’s quest provides visually stunning footage that captures the sheer beauty and raw force of a tornado as never seen before. There are moments

you feel you could be there, and some moments that you’re glad you’re not. The very real footage of homes utterly destroyed and their occupants, who have just lost everything, looking on in shock is a stark reality check. It reminds us of the importance of the work being undertaken by the scientific team. Throughout the film we are told that the data collected by the scientists will help increase warning times. The film ends with a tone of “mission accomplished”: the scientists have their data, and Casey has his footage. However, the reality is that these are merely steps in an ongoing battle. It is left unsaid that both teams will return next chase season, continuing to seek further examples of this beautiful yet destructive phenomenon. This article was first published on October 11, 2011 at The Conversation, www.theconversation.edu.au.

Articles

2011/12 Experimental Tropical Cyclone season forecast for the Australian region using a new Bayesian regression model Angelika Werner1 and Neil J. Holbrook2

Willis Research Network, London, UK Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia Address for correspondence: Angelika Werner, Willis Analytics, The Willis Building, 51 Lime Street, London EC3M 7DQ, UK. angelika.werner@willis.com 1 2

1. Introduction We provide here an Australian region (90°–170°E) seasonal forecast of 2011/12 tropical cyclone (TC) event probabilities and likelihood. It has been prepared using Bayesian regression models developed with largescale climate data and cross-validated over the 40-year period from 1968/69–2007/08 (Werner, 2011; Werner and Holbrook, 2011a,b,c). To include climatological information in the most meaningful way, these models have been developed based on the strength of relationships between large-scale climate “predictor” variables and tropical cyclone genesis (TCG) events for the upcoming Australian region tropical cyclone season (November– April). A step-by-step predictor selection based on the probabilistic root-mean-squared error and skill score ensured the most skilful model was developed. For the Australian TC season 2011/12 the model forecasts average conditions with a high likelihood of observing 13 TCs, equally distributed between the Indian Ocean and Pacific regions around Australia.

2. Australian region tropical cyclone forecast model Previous experimental and operational seasonal TC forecast models of the Australian region have generally Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 123

been built on classical El Niño-Southern Oscillation indices (i.e., sea surface temperature or sea level pressure anomalies). For the model presented here, large-scale climatologies of various atmospheric and oceanographic variables have been analysed and tested for their potential forecast skill, to fi nd the most relevant and meaningful predictor combinations for annual TCG count in the Australian region. The fi nal model for the Australian and eastern Australian subregion (135°–170°E) tropical cyclone counts (events) is based on a Bayesian approach. This uses a Poisson regression on indices of subtropical central Pacific June–July–August (JJA) average convective available potential energy (CAPE), the tropical northeast Pacific May–June–July average meridional winds at 850 hPa (v850) and subtropical central South Pacific JJA geopotential height at 500 hPa (Werner and Holbrook 2011a). The Australian region model shows considerable cross-validated hindcast skill during the observational period from 1968/69–2007/08 with correlation coefficients between the observed annual TCG event totals and crossvalidated model hindcasts of r = 0.73 for the Australian region and r = 0.79 for the eastern Australian subregion. A separate model for the southeast Indian Ocean (Western Australian subregion; 90°-135°E), based on indices of the JJA tropical central Pacific sea level pressure (SLP)


Figure 1. Upper panel: Map of anomalies during JJA 2011. Wind vectors describe the wind flow anomalies at 850 hPa. Shaded areas represent changes of CAPE (m2 s-2), contour lines show positive anomalies and dashed contour lines negative anomalies of geopotential height at 500 hPa (m). Also indicated are the  locations of the predictor indices CAPE, v850 and GPH and the Australian TC region. Lower panel: As above, but shaded areas represent changes of SST (°C), contour lines show positive anomalies and dashed contour lines negative anomalies of SLP (hPa). Also indicated are the locations of the predictor indices NINO4, v850 and SLP, as well as the Australian TC region. and v850 shows correlations between cross-validated hindcasts and observed annual TCG counts of r = 0.67 over the same period (Werner and Holbrook, 2011c). A model of the spatial distribution of Australian region TCG-event probabilities is seasonally forecast on a 2.5° x 2.5° grid using a separate Bayesian model developed on the logistic regression (Werner and Holbrook, 2011b). The model builds on SLP, NINO4 and v850 indices, combined with spatial information from CAPE and shows an average improvement in cross-validated hindcast skill over climatology of 15% during the 40-year period 1968/69–2007/08. Local biases over the Australian continent and Indonesia are removed in the process. The average distribution of TCG-event probabilities and crossvalidated hindcasts of TCG-event distributions during observed ENSO events match remarkably well over most of the study domain. The models, as well as model forecast skill for the past three Australian region tropical cyclone seasons (following the training period 1968/69–2007/08), are discussed in detail in the PhD thesis of Werner (2011). This thesis can be provided on request.

3. 2011/12 cyclone season a. Climatic conditions The climatic conditions during the austral winter (JJA) of 2011, and in the lead-up to the onset of the Australian region TC season of 2011/12, have been evolving towards a La Niña event year, based on forecasted classifications from NOAA using NINO3.4 anomalies1. Figure 1 shows 1.www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ ensoyears.shtml

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 124

the large-scale climate anomalies used to derive the model predictors. Interestingly, the sea surface temperature anomaly (SSTA) pattern shown in the lower panel reveals negative anomalies in the central tropical Pacific forming a boomerang-shaped pattern towards the eastern Pacific subtropics. Th is resembles less the classical La Niña pattern, but rather negative El Niño Modoki conditions, with weak positive SLP anomalies (SLPA) in the tropical central Pacific. There are strong SLPA in the southern midlatitudes, which are also evident in the geopotential height field anomalies (GPHA) at 500 hPa (upper panel). Th is indicates stronger pressure systems there, which increase blocking of the mid-latitude air masses towards lower latitudes. The central Indian Ocean is slightly warmer than normal with weak negative SLPA in the southern Indian Ocean. A reduced trade wind component can be seen in the tropical east Pacific corresponding to the Modoki-like SSTA. The CAPE anomaly pattern (upper panel) shows enhanced convection in the subtropical southwest Pacific, and reduced convection in the subtropical southeast Pacific and over northern Queensland. The predictors used in our models give a range of results. The CAPE index suggests higher than normal tropical cyclone activity, v850 is slightly positive indicating a weakened East Pacific Hadley cell in the Northern Hemisphere, and the GPHA is positive leading to increased blocking of mid-latitudinal air-masses and therefore allowing warm moist air masses favouring deep convection to establish in the Australian region. The SLPA index is neutral and NINO4 is weakly negative. Spatially, in the TC formation regions, CAPE is neutral, albeit with a negative anomaly


Table 1 Number of TCGs forecasted for the Australian region and its subregions West and East for the TC season 2011/2012. Shown are the number of tropical cyclones forecasted with the highest probability, the median and the 75%, 90%, 95% and 99% quantiles of storms expected. Mean (1968–2007)

Mean (1998–2007)

Max (p)

Median

75%

90%

95%

99%

Australian

14.2

11.5

13

13

16

19

20

23

West

7.4

6.5

6

6

8

9

11

13

East

6.8

5

6

6

7

9

10

13

over northern Australia and weak positive anomalies at the southern boundaries of the Australian region. Overall, the predictors favouring increased TCG-event likelihood are almost in balance with those suppressing this likelihood.

b. Model Forecasts Figure 2 shows the model forecasts for the Australian region TC season of 2011/12. For the Australian region, 13 TCG events are expected, with a roughly even split between the West and East subregions. Table 1 summarises the statistics of the probabilistic forecasts. The median for the Australian region is 13 TCG events, with a 25% chance of experiencing 16 or more TCG events. There is a 5% probability of more than 20 TCG events occurring in the Australian region during the 2011/2012 season. There is a 5–10% chance that we may see at least 10 TCG events in either of the two subregions. Overall, the forecast is mirroring the average conditions we expect from the large-scale climatology, as discussed in the previous section and shown in Figure 1. The spatial distribution of TCG-event probabilities in Figure 2 shows maxima in the southeast Indian Ocean around 10°-15°S, 110-120°E and 5°-15°S, 120°-130°E. In the Pacific, local probability maxima are found to the east of Papua New Guinea and along the North Queensland coast between Mackay and Cairns.

Caveat: This forecast is an experimental product and is provided “as is” and without any warranty, including the implied warranties of merchantability and fitness for a particular purpose. The reader is forewarned that the methods/forecasts are new and subject to future change and improvement. The names of the authors may not be used to imply any kind of endorsement.

References Werner A., 2011. Seasonal Forecasting of Tropical Cyclone Formation in the Australian Region, Macquarie University, PhD thesis, 209pp. Werner A. and Holbrook, N.J., 2011a. A Bayesian forecast model of Australian region tropical cyclone formation, Journal of Climate, 124, 6114–6131, doi: 10.1175/2011JCLI4231.1. Werner A., and Holbrook, N.J., 2011b. A probabilistic seasonal forecast model of tropical cyclone formation and distribution for the Australian region, (in preparation). Werner A. and Holbrook, N.J., 2011c. Improving statistical seasonal forecasts of tropical cyclone numbers in the southeast Indian Ocean, (in preparation).



Figure 2 left side: Probability distributions of the annual total number of TCG occurrences forecasted for the season 2011/12 for the Australian TC region and its subregions West and East. Model standard deviations are indicated by the shading. Right side: Spatial (2.5°x2.5° resolution) probability of TCG forecasted for the season 2011/12 for the Australian TC region.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 125


A note on climatonomy John Bye

Associate Professor (Principal Fellow), School of Earth Sciences, University of Melbourne An almost forgotten word is Climatonomy, which was introduced by Heinz Helmut Lettau at the 1954 meeting of the American Geophysical Union in Washington D.C. (Lettau, 1969). In a later paper (Martin and McBean, 1971), Lettau states that “Climatonomy is described as a theoretical modelling technique for local climates which is analogous to the approach of systems engineers to design problems. The technique provides for prediction of the climate change resulting from modification of any single parameter in the system.” Etymologically, climatonomy is concerned with discovering the laws (mathematical relationships) of climate (nomos — law) in distinction to climatology which involves talking about climate (logos — talk) (Schwerdtfeger, 1974). Thus climatonomy is the antecedent of climate science, and the original term for a climate scientist is the less appealing title of climatonomer. A parallel usage is astronomer, from astronomy (the science of the heavenly bodies). Is there also a parallel between astrology (study of reputed influence of stars on human affairs, Oxford, 1960) and

climatology? The answer is yes — for the meaning of climatology, just replace “stars” by “environment”. Climatology is quite distinct from climatonomy and hence also from climate science. Professor Lettau died on 3 August 2005 at the age of 95 in Mount Pleasant, South Carolina.

References Lettau, H.H., 1969. Evapotranspiration climatonomy I.A new approach to numerical prediction of monthly evapotranspiration, runoff, and soil moisture storage. Monthly Weather Review, 97, 691–699. Martin, H. and McBean, G., 1971. Chronicle: The Second Canadian Conference on Micrometeorology BoundaryLayer Meteorology, 2, 255–257. Oxford, 1960. The Oxford School Dictionary (Second Edition). Oxford Univ. Press. Schwerdtfeger, P., 1974 . Climatonomy. Selected Topics in Atmospheric and Marine Sciences 5. Flinders Institute for Atmospheric and Marine Sciences.

A note on John Bye, one of our prominent members Alex Pezza Lecturer, School of Earth Sciences, University of Melbourne I have known John Bye since June 2004, when I arrived in Australia, and have had the privilege of working with him at The University of Melbourne. John is not the type of person anyone would easily forget. His profound integrity of character, cheerful yet humble personality and enormous sense of scientific curiosity are a vital part of his identity. Yet there is so much more about him that makes him special. John was born in 1936 in England where he started his studies and career before moving to Australia. He has an Oceanography degree from Liverpool University, and was awarded a PhD in Meteorology from London University after defending his thesis entitled “Wind-stress induced circulations in small basins and lakes”. John has a vast experience in academic life and teaching. He has held several positions as Lecturer, Senior Lecturer and Associate Professor at Flinders University in South Australia where he resided most of his life. While in Flinders he was influential in the education of successful researchers and academics such as Ian Simmonds (Professor at the University of Melbourne and recipient

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 126

 Associate Professor and Principal Fellow, Dr John Bye.


of the AMOS medal in 2000), who did his PhD at Flinders while John was a Lecturer. John joined The University of Melbourne in 2000 as Associate Professor (Principal Fellow) at the School of Earth Sciences, and remains a very active contributor of our department today. To give an idea of what I mean by active, John has written 11 papers so far in 2011 (between published, in press and submitted), characterising one of the most active years of his career. He has been publishing in the peer-reviewed literature since 1961, with more than 120 papers to date and several book chapters and research and ship cruise reports from his many Southern Ocean expeditions and work in Antarctica. John’s research is vast and diverse, ranging from purely theoretical pursuits such as solving the Navier-Stokes equations to ground breaking fi ndings on the discovery of new ocean currents (e.g. his seminal work on the Flinders Current south of Australia). His research also includes the study of water balance, sea level and climate change, heat fluxes, pollution dispersion in water, drag coefficients and much more. John’s research has gained significant multidisciplinary flavour with papers on pollen concentration in Melbourne (one that I had the privilege to co-author after a joint student supervision), atmosphericocean momentum exchange, Lake Eyre, tropical cyclones and polar ice sheets, temperature lags and wind speed

forecasting and many others. In 1996, when the awareness of climate change was still emerging, John co-authored a thought-provoking paper in Nature about the differences between climate change and global warming. John still travels the world frequently, particularly to Europe where he is a regular guest visitor of renowned institutions including the University of Hamburg in Germany, where he has a number of research connections. I have had the great privilege of enjoying John’s company on many occasions research-wise and otherwise, including being a guest in his lovely country-house in South Australia where the red wine in front of the fi re place, excellent food and hospitality (both of him and his wife Helene, and their family dog Henry) reminded me how small we would all become without our deeper and more meaningful human interactions. I thank John deeply for his generosity and the invaluable experiences that he has shared with our community over the years. John is always looking for new research topics and collaborators and would be delighted to hear about new scientific ideas that you may have. Simply send him an e-mail at jbye@unimelb.edu.au. I look forward to a continuing scientific collaboration and friendship!

Meet a Member

Steven Sherwood Where does this find you? It’s Cup Day and I just returned home from playing hooky at the pub (don’t tell anyone). What do you do? I am a professor and Director of the UNSW Climate Change Research Centre. My research area is clouds and water vapour and their connections to climate via convection and larger-scale dynamics. Why did you get into it? I loved physics as an undergraduate. Meteorology or Earth Sciences were not on my radar at all (so to speak). Attempts to find applications to something interesting and practical led, after a two-year stint studying the susceptibility of military gadgets to radio frequency radiation, to grad school in applied physics at UC San Diego. My favourite course was fluid dynamics, taught by oceanographer Clint Winant. The topic of climate and climate change, which had recently entered the news in the US, intrigued me as a physics problem. People were working on this and I moved into Veerabhadran Ramanathan’s research group which united radiation and fluids. Th ings sort of went from there. Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 127

Professor Steven Sherwood


What is the best thing about what you do?

How do you relax?

Being a scientist is one of the best jobs there is (once you get past the period of uncertainty and anxiety known as Being a Postdoc). You get paid to solve problems and learn new things. Those occasions where you figure something out, that is interesting to both you and to others, they are also great experiences. You also get to travel a lot (often too much, though I try to avoid that!).

Lately I’ve gotten back into reading, which is a great pleasure that I used to do more of.

What did you want to be when you were 10? I think I wanted to be something “outdoorsy” like a forest ranger. It doesn’t look like that has worked out but at least I have a beach down the street.

What is your favourite holiday destination? My family and I are still exploring Oz — it’s all really interesting but we don’ have any particular favourites yet (we’ve been here for three years). The reef is a key target for the future. Farther afield (when we get the chance) I love exploring New Zealand’s “tramping tracks” and the French countryside.

Snapshot

Roll clouds, Carnarvon Western Australia February, 2011 Andréa Bride

This roll cloud was followed by thunderstorms, dust storms, large dust devils, 20 mm rain in as many minutes, wind gusts of 45kts, frequent wind direction changes (up to 100 degrees in 2 mins!), and a large drop in temperature from 38° to 25°C.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 128

It caused chaos for the Weather Observer on duty at the airport at the time, i.e. me! Many thanks to Andréa and all who have submitted photos this year. If you have an image to share, email it to l.ashcroft@student.unimelb.edu.au. –Ed.


Significant Mesoscale Oceanography

December 2011 Andy Taylor and Gary Brassington

Centre for Australian Weather and Climate Research (CAWCR), Melbourne

News The Bureau of Meteorology ocean forecasting system was upgraded in December 2011. Version 2 of the Ocean Model, Analysis and Prediction System (OceanMAPSv2) includes a number of improvements that provide ~20–30% reduction in errors for sea surface height anomalies and sea surface temperatures (SSTs) with similar improvements expected for other less well observed correlated variables (Brassington et al., 2010). The new system also includes a daily forecast and a multi-cycle time-lagged ensemble that provides guidance products on the uncertainty of the forecasts. The system and performance are summarised in a CAWCR tech report that is in press but can be obtained from the CAWCR Marine and Ocean Forecasting group. Enhancements have also been made in terms of the data products to bring them up to community metadata standards and a specific surface product with 3 hourlyaveraged fi elds has been created to improve tracking of diurnal and coastal processes.

Remote sensing sea surface salinity On 10 June 2011 the Aquarius/SAC-D was launched with the mission to observe the ocean sea surface salinity. On the 25th of August the satellite was declared operational which was followed by the release of the first global maps of sea surface salinity on the 22nd of September (NASA, 2011).

Aquarius is designed to observed passive microwave radiation (Koblinsky et al., 2003). Robinson (1985) provides a comprehensive description of the physics behind this particular measurement related to the ocean. Part of the return signal is a function of the ocean’s emissivity and related to sea surface salinity. Given a known SST and frequency, the salinity can be expressed as directly proportional to brightness temperature (TB) of the passive microwave. Aquarius carries three radiometers in a push broom alignment which have an incident angle of 28.7°, 37.8° and 45.6° to the ocean surface respectively. The three beams have a surface foot print of 74 km alongtrack × 94 km cross-track, 84 km × 120 km and 96 km × 159 km respectively. The retrieved TB is sensitive to the surface roughness. In addition to the three radiometers, Aquarius has an on-board scatterometer to observe the surface roughness in real-time. The observed TB is also sensitive to the incident radiation from the sun and uses a sun-synchronous orbit with equator crossing times of 6am (descending) and 6pm (ascending) to minimise noise and maximise coverage. The Aquarius mission (and an European Space Agency mission, ESA, 2011) offer the fi rst global maps of sea surface salinity (based on Wentz and LeVine, 2008). However, these products require a comprehensive calibration and validation exercise to manage the sensitivity of the observations. A number of campaigns are planned for multi-instrument in situ observations as



Figure 1 Variability of sea surface salinity in the Australian region modelled by the Ocean Forecast Australia Model (OFAM) based on a 17-year spinup integration forced by surface fluxes from ERA-40. Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 129






Figure 2 Daily mean surface current magnitude from the Bureau of Meteorology, OceanMAPSv1 system on 21 December 2008. part of the Salinity Processes in the Upper Ocean Regional Study (SPURS) aiming to study the global water cycle. Part of this campaign are modified surface drifting buoys fitted with high quality salinity sensors. The majority of these missions are planned for the northern hemisphere. The only planned deployments in Australia’s region are a small deployment in the Coral Sea as part of a western Pacific campaign. In the absence of an extensive campaign of in situ observations an alternative approach for the Calibration/ Validation is being investigated for the Australian region. This approach exploits regions of the ocean that exhibit low spatial and temporal salinity variability. Figure 1 shows the distribution of variability of sea surface salinity modelled by the Ocean Forecast Australia Model (OFAM) from a 17-year spinup integration forced by ERA40 surface fluxes. Several locations in the Australian region exhibit low salinity variability, including narrow bands in the southeast Indian Ocean, the Southern Ocean, the Great Australian Bight, the northern Tasman Sea and the Campbell Plateau south of New Zealand. Due to the width and separation of the beams there are near coincident tracks at latitudes near the Campbell Plateau which is modelled as having the lowest variability. The Campbell Plateau has been observed by underway measurements from the Research Vessel (RV) Tangaroa operated by NIWA, New Zealand. Observations from three separate cruises in 2008 and 2010 show low spatial and temporal variability with a salinity range of 34–34.2 psu (Murray Smith, personal communication). The Campbell Plateau has a depth of between 500 and 1500 m (Adams, 1962) and forms part of the Zealandia continent. The Campbell Plateau is characterised by a convergence of the Antarctic Circumpolar Current along is southern edge where there is a very rapid decent of ~5 km and a corresponding sharp gradient in potential vorticity. Along Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 130

the northern edge a current links up with the subtropical front along Chatham Rise. Over the Plateau however the currents are persistently weak, indicating that it may act as a large Taylor Column and a have relatively low exchange of mass. The ocean state in this region appears to be relatively stable with the surface fluxes contributing a small perturbation relative to the depth of the water column >500 m. Further investigation is being undertaken of this promising location for calibration/validation of Aquarius.

References Adams, R. D., 1962. Thickness of the earth’s crust beneath the Campbell Plateau, N. Z. J. Geol. Geophys., 5, 74–85. Brassington et al., 2011. Ocean Model, Analysis and Prediction System (OceanMAPS): version 2, CAWCR Technical Report (in press). ESA, 2011. Living Planet Programme, available from www.esa.int/esaLP/LPsmos.html. Koblinsky, C. J., Hildebrand, P., Le Vine, D., Pellerano, F., Chao, Y., Wilson, W., Yueh, S. and Lagerloef, G., 2003. “Sea surface salinity from space: Science goals and measurement approach”. Radio Science, 38(4), doi:10.1029/2001RS002584. NASA, 2011. Aquarius Mission Web Site, available from http://aquarius.nasa.gov/. Robinson, I. S., 1985. Satellite oceanography: an introduction for oceanographers and remote-sensing scientists. John Wiley and Sons, 456pp. Wentz, F. J. and LeVine, D., 2008. Algorithm Theoretical Basis Document, Aquarius level-2 radiometer algorithm: revision 1, RSS Technical Report 012208.


Charts from the Past with Blair Trewin

26 May 1925 Like London buses and Melbourne trams, Australian east coast lows sometimes come in rapid succession. June 1950 and June 2007 are examples of months where several have occurred in the space of a few weeks, bringing exceptional rainfall accumulations to parts of the east Australian coast. May 1925 was such a month. The fi rst major event of the month affected the coasts of NSW and southern Queensland from the 8th to the 11th, the highest daily totals being 393 mm at Dunwich on Stradbroke Island and 407 mm at Robertson in the NSW Southern Highlands, whilst a second event on the 19th saw 282 mm fall at Nelligen, inland from Batemans Bay. The third and biggest event of the month came in the final week, when two separate lows formed in a trough near the east coast. This brought widespread rain over eastern Australia, with the most dramatic conditions occurring from Sydney southwards. The Sydney area was the fi rst to be hit on the 26th, with severe gales, especially on the coast. The worst damage was at Collaroy where several dozen houses were severely damaged or destroyed, and there were numerous tram derailments. By then, though, the most extreme rainfalls had set in on the southern flank of the low, focused on the NSW South Coast and adjacent tablelands. The highest totals were at Araluen, near Braidwood, which had 632 mm over the three days 26–28 May, including 402 mm on the 27th. On the coast Moruya Heads had a daily total of 275 mm (and wind gusts to 120 km/h), whilst further inland,

Queanbeyan had 189 mm, Lambrigg 182 mm (an ACT daily record) and the then Canberra site 174 mm. Such extreme rainfalls on already saturated ground resulted in severe fl ooding. There were record fl oods and major property inundation at both Moruya and Queanbeyan, with the Queanbeyan fl ood more than a metre above the next worst in more than a century of data. In Canberra, the approaches to the old Commonwealth Avenue bridge were washed away, and there was major damage to a hydroelectric plant under construction at Burrinjuck Dam, whilst there was also severe fl ood damage at Yass and Gundagai. There were fears of record flooding at Wagga Wagga too, but in the end the Murrumbidgee’s peak there was below the 1891 level, and ranks third overall. Other rivers to experience major flooding included the Shoalhaven (for the second time in a fortnight) and the Wollondilly. Five deaths were attributed to the flooding. The multiple major rain events resulted in some extraordinary monthly totals. Nelligen had 1271 mm for the month, with four daily totals in excess of 190 mm, whilst Araluen totalled 1204 mm, and Braidwood 664 mm. The first two are the two heaviest monthly totals ever recorded in Australia south of Port Macquarie. All these exceeded the annual average for the sites, and despite the remaining eleven months of the year being drier than normal, Araluen still had its wettest year on record. Braidwood had four days during the month with 100 mm or more, and has had only three more in its remaining 120 years of data.

 Synoptic chart for 0900 AEST, 26 May 1925.

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 131


Calendar

2012 January 22–26 AMS Annual Meeting, New Orleans, USA. 31–3 Feb AMOS 2012 Conference: Connections in the Climate System, Sydney.

February

May 29–1 June AMS 25th Conference on Weather Analysis and Forecasting (WAF) and the 21st Conference on Numerical Weather Predition (NWP) Jointly with the 46th Canadian Meteorological and Oceanographical Society (CMOS) Congress 2012 Montreal, Quebec, Canada.

June

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

11–15 AGU Chapman Conference on Volcanism and the Atmosphere, Selfoss, Iceland.

24–28 Association of American Geographers Annual Meeting, New York, USA.

24–27 35th International Association for Energy Economics International Conference, Perth.

April

July

22–27 International Polar Year 2012: From Knowledge to Action, Montreal, Canada. 22–27 EGU General Assembly 2012, Vienna, Austria. 23–27 10th ISCHMO, Nouméa, New Caledonia. 25–30 AMS 30th Conference on Hurricanes and Tropical Meteorology, Florida, USA.

8–13 20th Symposium on Boundary Layers and Turbulence and 18th Conference on Air-Sea Interaction, Boston, USA.

August 13–17 AOGS–AGU (WPGM) Joint Assembly, Sentosa Singapore 26–30 32nd International Geographical Congress, Cologne, Germany.

Australian Meteorological and Oceanographic Journal

Articles — Vol 61 No. 3, September 2011 Allen, Karoly and Mills. A severe thunderstormc climatology for Australia and associated thunderstorm environments. Hameed, Iqbal, Rehman, and Collins. Impact of the Indian Ocean High Pressure System on Winter Precipitation over Western Australia and Southwest Western Australia. Fleming, Awange, Kuhn and Featherstone. Evaluating the TRMM 3B43 monthly precipitation product using gridded rain-gauge data over Australia

Bulletin of the Australian Meteorological and Oceanographic Society Vol.24 page 132

Regular features: Lovitt. Seasonal climate summary southern hemisphere (spring 2010): La Niña strengthens. Qi. Quarterly Numerical Weather Prediction Model Performance Summaries — April to June 2011.


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 Robin Roberston Sandra Schuster Perry Wiles

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

AMOS Administrative Officer

Jeanette Dargaville GPO Box 1289, Melbourne VIC 3001 (attn: AMOS admin officer) Phone 0404 471 143 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 NSW Hobart Melbourne ACT Perth Darwin Brisbane Adelaide

Michael Pook Mark Williams Val Jemmeson Phillip Riley

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

Steven Phipps Kelvin Michael Damien Irving Margi Bรถhm Merv Lynch Hakeem Shaik Hamish McGowan Caecilia Ewenz

02-9385 8957 03-6226 2977 03-9239 4685 02-6268 8749 08-9266 7540 08-8920 3814 07-3365 6651 08-8366 2723

Representatives AMM Science & Technology Australia

Kathy McInnes

03-9239 4569

Steven Phipps

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 (NSW) Clem Davis (ACT)

Contributors Blair Trewin Gary Brassington Paul Sandery Andy Taylor

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 20 January 2012. 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


Bulletin vol 24 no 6 dec 2011