Multi-year assessment of atmospheric circulation and impacts on air temperature variation on James Ross Island, Antarctic Peninsula
|Článek v odborném periodiku
|Časopis / Zdroj
|International Journal of Climatology
|Fakulta / Pracoviště MU
|Antarctic Peninsula; James Ross Island; air temperature; synoptic climatology; pattern detection
|The influence of synoptic-scale circulation on air temperature variation in the ice-free areas and glaciated areas on the eastern side of the Antarctic Peninsula have been analysed. For this purpose, a new classification of atmospheric circulation with fifteen synoptic patterns in the Antarctic Peninsula Region was developed using a self-organizing maps technique. The synoptic patterns were compared with air temperature observations from coastal and glacial sites on James Ross Island, north-eastern Antarctic Peninsula, in the period 2005–2015. The most frequent synoptic pattern with a frequency of 13.7 % was dominated by a low-pressure centre in the north-western Bellingshausen Sea, which extended over the Antarctic Peninsula to the Weddell Sea. On the other hand, the largest interannual variability was observed for a synoptic pattern with a low-pressure centre in the southern Bellingshausen Sea. This synoptic pattern also had the highest air temperature anomalies at both investigated sites year-round. Air temperature anomalies at the lower lying site (Mendel station) were the lowest during a high-pressure ridge dominating the AP Region due to a combination of local and synoptic-scale processes. At the glacial site, however, southerly barrier winds advecting cold air from the ice-covered Weddell Sea during a strong low-pressure system in the Weddell Sea ensured the coldest air temperature anomalies.