Meteorological observations at Syowa Station in 2005 by the 46th Japanese Antarctic Research Expedition

This report describes the results of meteorological observations at Syowa Station from February 1st, 2005 to January 31st, 2006, carried out by the Meteorological Observation Team of the 46th Japanese Antarctic Research Expedition (JARE-46). The observation methods, instruments and statistical methods used by the JARE-46 were almost the same as those used by the JARE-45 observation team. Remarkable weather phenomena observed during the period of JARE-46 are as follows.1) Annual mean relative humidity and cloud amount in 2005 at Syowa Station were 73 and 7.5, both records for Syowa Station. Annual mean wind speed and number of snow days were 7.2m/s and 228 days, both second highest values.2) There were 30 blizzards of which 6 were class A, 9 class B and, 15 class C, typical of a normal year.3) The amount of total ozone over Syowa Station became lower than or equal to 220m atm-cm from the end of August to mid-October. Monthly mean amount of total ozone in September was 173m atm-cm, which was the 4th lowest value in the historical record. On 4th October, the amount of total ozone was 136m atm-cm, which was the lowest value during JARE-46