FRAM FORUM 2016
WEATHER CONDITIONS ON 14 JANUARY 1987 Left: Satellite image showing a storm system in the Barents Sea, centred around Svalbard, with a frontal structure that reaches mid-Norway (star marks HornĂ¸ya; wintering areas of common guillemots shown in orange). Right: A strong low pressure system, with core pressure less than 980 hPa (right, units: Pa for Pascal). Satellite image provided by Prof. Humberto Barbosa (UFAL, Brazil, www.lapismet.com) Pressure chart provided by Physical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA. http://www.esrl.noaa.gov/psd/
CAUSE-AND-EFFECT CORROBORATED BY PHYSICAL MECHANISMS Our results showed that the NAO pattern was not a visible feature in point maps. So, if we had found a correlation between the NAO and the growth rate of common guillemots, this would not have been corroborated by the physical mechanisms â€“ and the correlation would have been spurious. This means that other atmospheric systems are at play in influencing the guillemot growth rate. Through our analysis, we found that an anomalous winter low-pressure system over the Barents Sea is associated with higher population growth rates: low pressure brings storms into the region and creates warmer conditions. The opposite is true in winters with anomalous high-pressure systems over the Barents Sea. The crash in 1986/87 could be explained by the extreme conditions that winter: a severe anomalous high-pressure system over the region and polar lows.