|Authors||Y. Wang, D. Zhou, A. Bunde and S. Havlin|
|Title||Testing reanalysis data sets in Antarctica: Trends, persistence properties, and trend significance|
|Publication Type||Journal Article|
|Year of Publication||2016|
|Journal||Journal of Geophysical Research - Atmospheres|
|Publisher||American Geophysical Union (United States)|
The reanalysis datasets provide very important sources for investigating the climate dynamics and climate changes in Antarctica. In this paper, five major reanalysis data are compared with observational Antarctic stations data over the last 36 years: the National Centers for Environmental Prediction and the National Center for Atmospheric Research Reanalysis (NCEP1), NCEP-DOE Reanalysis 2 (NCEP2), the European Centre for Medium-Range Weather Forecasts Interim Reanalysis (ERA-Interim), the Japanese 55-year Reanalysis (JRA-55), and the National Aeronautics and Space Administration (NASA) Modern-Era Retrospective-analysis for Research and Applications (MERRA). In our assessment, we compare the linear trends, the fluctuations around the trends, the persistence properties and the significance level of warming trends in the reanalysis data with the observational ones. We find that NCEP1 and NCEP2 show spurious warming trends in all parts of Antarctica except the Peninsula and JRA-55 exhibits spurious warming trends at several East Antarctic stations. On the other hand, ERA-Interim and MERRA are quite reliable, with only few exceptions. To investigate the persistence of the datasets, we consider the lag-1 autocorrelation C(1) and the Hurst exponent α. While C(1) varies quite erratically in different stations, the Hurst exponent shows similar patterns between observational and reanalysis data all over Antarctica. Regarding the significance of the trends, NCEP1 and NCEP2 differ considerably from observational datasets by strongly exaggerating the warming trends. Moreover, JRA-55 provides significant warming trends at Casey and Amundsen-Scott. In contrast, ERA-Interim and MERRA give reliable results at most stations except at Amundsen-Scott where ERA-Interim shows a significant cooling trend.