Meteorological observations at Syowa Station in 2006 by the 47th Japanese Antarctic Research Expedition

Abstract

This report describes the results of meteorological observations at Syowa Station from February 1st, 2006 to January 31st, 2007, carried out by the Meteorological Observation Team of the 47th Japanese Antarctic Research Expedition (JARE-47). The observation methods, instruments and statistical methods used by JARE-47 were almost the same as those used by the JARE-46 observation team.Remarkable weather phenomena observed during the period of JARE-47 are as follows.1)The monthly mean temperature in July in 2006 at Syowa Station was -24.1°C, which was the lowest record for Syowa Station.2)The temperature of the lower part of the stratosphere over Syowa Station was lower than normal from winter to early spring in 2006. Especially, the minimum temperature at many standard pressure levels under 70 hPa set the lowest record in each month from August to October. On the other hand, in the troposphere, due to the A-class blizzard on 7-10 October, the maximum temperature at the standard pressure level from 850-350 hPa set the highest record in October.3)The amount of total ozone over Syowa Station became lower than or equal to 220 m atm-cm from the end of August to mid-October. The monthly mean amount of total ozone in September was 173 m atm-cm, which was the 4th lowest value in the historical record. On 4th October, the amount of total ozone was 136 m atm-cm, which was the lowest value during JARE-46.The amount of total ozone over Syowa Station on October 17th, 2000 was 114 m atm-cm, which was the lowest record. The monthly mean amount of total ozone in October was 137 m atm-cm, which was the lowest record. It was below half compared with the value before 1980 when the ozone hole had not yet appeared. The recovery of the total amount of ozone was slower than usual, in January 2007.