An assessment of historical Antarctic precipitation and temperature trend using CMIP5 models and reanalysis datasets

• Published in: Polar Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Antarctica; CMIP5; Reanalyses; Precipitation; Temperature; Antarctic; Merra; Antarc*; Polar Science
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=14981; http://id.nii.ac.jp/1291/00014900/

The study of Antarctic precipitation has attracted a lot of attention recently. The reliability of climate models in simulating Antarctic precipitation, however, is still debatable. This work assess the precipitation and surface air temperature (SAT) of Antarctica (90 oS to 60 oS) using 49 Coupled Model Intercomparison Project phase 5 (CMIP5) global climate models and the European Centre for Medium-range Weather Forecasts “Interim” reanalysis (ERA-Interim); the National Centers for Environmental Prediction Climate Forecast System Reanalysis (CFSR); the Japan Meteorological Agency 55-year Reanalysis (JRA-55); and the Modern Era Retrospective-analysis for Research and Applications (MERRA) datasets for 1979–2005 (27 years). For precipitation, the time series show that the MERRA and JRA-55 have significantly increased from 1979 to 2005, while the ERA-Int and CFSR have insignificant changes. The reanalyses also have low correlation with one another (generally less than +0.69). 37 CMIP5 models show increasing trend, 18 of which are significant. The resulting CMIP5 MMM also has a significant increasing trend of 0.29 ± 0.06 mm year−1. For SAT, the reanalyses show insignificant changes and have high correlation with one another, while the CMIP5 MMM shows a significant increasing trend. Nonetheless, the variability of precipitation and SAT of MMM could affect the significance of its trend. One of the many reasons for the large differences of precipitation is the CMIP5 models' resolution. 近年、南極の降水に関する研究は注目を浴びている。気候モデルによる南極の降水量シミュレーションについての信頼性は、依然、議論のあるところである。本研究は、南極の降水量と地上気温を、結合気候モデル相互比較計画フェーズ５（CMIP5）の49の全球気候モデルと、ヨーロッパ中期予報センター・インテリム再解析（ERA-Interim）、アメリカ環境予測気候予報センター・システム再解析（CFSR）、気象庁55年再解析（JRA-55）、MERRA再解析データ1979—2005年を使って評価した。降水に関しては、時系列データからMERRA とJRA-55 では1979—2005年に増加しているのに対し、ERA-IntとCFSRでは変化していない。再解析データ同士は相関が低かった（通常0.69以下）。CMIP5モデルでは37モデルが増加傾向で、そのうち18は有意であった。CMIP5多モデル平均値（MMM）も0.29±0.06 ...