Mar 1, 2017

Evaluating Highest Temperature Extremes in the Antarctic - Eos

Skansi, M. d. L. M., et al. 2017

... On the continent, [WMO] verified that a high-temperature extreme of 17.5°C (63.5°F) occurred on 24 March 2015 at the Argentine research base Esperanza, located near the northern tip of the Antarctic Peninsula.



Esperanza is located near the northern tip of the Antarctic Peninsula just to the east of the Antarctic Peninsula mountains, which rise to around 1000 meters near this location (Figure 1). This temperature extreme occurred on the day following a reading of 17.4°C (63.3°F) measured at the Argentine research base Marambio, about 100 kilometers southeast of Esperanza, on 23 March 2015.


ERA reanalysis for this location at the time of the temperature extreme shows a northwest–southeast warm high-pressure ridge stretching from South America to the Antarctic Peninsula in concert with a cold trough of low pressure lying over the far South Pacific near 120°W. Together, these features drove a strong northwesterly circulation that was associated with warm air advection and strong winds perpendicular to the mountain chain in the northern part of the peninsula, conducive to the development of a foehn at Esperanza (Figure 3b).