DOI: 10.5194/tc-8-1361-2014
Scopus记录号: 2-s2.0-84904353508
论文题名: Using MODIS land surface temperatures and the Crocus snow model to understand the warm bias of ERA-Interim reanalyses at the surface in Antarctica
作者: Fréville H ; , Brun E ; , Picard G ; , Tatarinova N ; , Arnaud L ; , Lanconelli C ; , Reijmer C ; , Van Den Broeke M
刊名: Cryosphere
ISSN: 19940416
出版年: 2014
卷: 8, 期: 4 起始页码: 1361
结束页码: 1373
语种: 英语
英文摘要: Moderate-Resolution Imaging spectroradiometer (MODIS) land surface temperatures in Antarctica were processed in order to produce a gridded data set at 25 km resolution, spanning the period 2000-2011 at an hourly time step. The Aqua and Terra orbits and MODIS swath width, combined with frequent clear-sky conditions, lead to very high availability of quality-controlled observations: on average, hourly data are available 14 h per day at the grid points around the South Pole and more than 9 h over a large area of the Antarctic Plateau. Processed MODIS land surface temperatures, referred to hereinafter as MODISTs values, were compared with in situ hourly measurements of surface temperature collected over the entirety of the year 2009 by seven stations from the Baseline Surface Radiation Network (BSRN) and automatic weather stations (AWSs). In spite of an occasional failure in the detection of clouds, MODISTs values exhibit a good performance, with a bias ranging from ĝ̂'1.8 to 0.1 °C and errors ranging from 2.2 to 4.8 °C root mean square at the five stations located on the plateau. These results show that MODISTs values can be used as a precise and accurate reference to test other surface temperature data sets. Here, we evaluate the performance of surface temperature in the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis known as ERA-Interim reanalysis. During conditions detected as cloud free by MODIS, ERA-Interim shows a widespread warm bias in Antarctica in every season, ranging from +3 to +6 °C on the plateau. This confirms a recent study which showed that the largest discrepancies in 2 m air temperature between ERA-Interim and the global temperature data set HadCRUT4 compiled by the Met Office Hadley Centre and the University of East Anglia's Climatic Research Unit occur in Antarctica. A comparison with in situ surface temperature shows that this bias is not strictly limited to clear-sky conditions. A detailed comparison with stand-alone simulations by the Crocus snowpack model, forced by ERA-Interim, and with the ERA-Interim/land simulations, shows that the warm bias may be due primarily to an overestimation of the surface turbulent fluxes in very stable conditions. Numerical experiments with Crocus show that a small change in the parameterization of the effects of stability on the surface exchange coefficients can significantly impact the snow surface temperature. The ERA-Interim warm bias appears to be likely due to an overestimation of the surface exchange coefficients under very stable conditions. © Author(s) 2014. CC Attribution 3.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/74814
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: CNRM-GAME UMR3589, Météo-France, CNRS, Toulouse, France; University Grenoble Alpes, LGGE UMR5183, 38041 Grenoble, France; CNRS, LGGE UMR5183, 38041 Grenoble, France; Institute of Atmospheric Sciences and Climate, Bologna, Italy; Institute for Marine and Atmospheric Research Utrecht, University of Utrecht, Utrecht, Netherlands
Recommended Citation:
Fréville H,, Brun E,, Picard G,et al. Using MODIS land surface temperatures and the Crocus snow model to understand the warm bias of ERA-Interim reanalyses at the surface in Antarctica[J]. Cryosphere,2014-01-01,8(4)