Meteorological observations at Syowa Station, Antarctica, 2012 by the 53rd Japanese Antarctic Research Expedition

This report describes the results of meteorological observations at Syowa Station from February 1st, 2012 to January 31st, 2013, carried out by the Meteorological Observation Team of the 53rd Japanese Antarctic Research Expedition (JARE-53). The observation methods, instruments and statistical methods used by JARE-53 were almost the same as those used by the JARE-52 observation team. Remarkable weather phenomena observed during the period of JARE-53 are as follows. 1) The temperature difference between the winter and the next summer was considerably large. In the winter, the temperature dropped below −40 degrees C on May 25th for the first time in May. The daily minimum temperature of −43.9 degrees C on September 13th updated the record ranking second place. In the next summer, rain was observed for the first time in 9 years, and the monthly mean temperature of 0.8 degrees C on January 2013 updated the record ranking second place. 2) The lower stratosphere monthly mean temperatures during January and February over Syowa Station were almost lower than normals and updated records low for some standard isobaric surfaces. In contrast, the troposphere monthly mean temperatures at February were almost higher than normals and updated records high for some standard isobaric surfaces. In addition, the troposphere and the lower stratosphere monthly mean temperature during July and January 2013 were almost higher than normals and updated records high for some standard isobaric surfaces. 3) The total ozone over Syowa Station was considerably below 220 m atm-cm which is a measure of the ozone hole from early-September, however, was frequently above the measure in October and recovered from mid-November. The monthly means of total ozone in ozone hole period were larger than the reference values