Cloud radiative effects （CREs） at the top of the atmosphere （TOA） in three reanalysis datasets （the Eur- opean Center for Medium-Range Weather Forecasts In- terim Reanalysis （ERA-Interim）, the Japanese 55-yr Re...Cloud radiative effects （CREs） at the top of the atmosphere （TOA） in three reanalysis datasets （the Eur- opean Center for Medium-Range Weather Forecasts In- terim Reanalysis （ERA-Interim）, the Japanese 55-yr Re- analysis Project （JRA-55）, and the Modem-Era Retro- spective Analysis for Research and Applications （MERRA）） are evaluated using recent satellite-based observations. The reanalyses can basically capture the spatial pattern of the annual mean shortwave CRE, but the global mean longwave CRE in ERA-interim and JRA55 is weaker than observed, leading to overestimations of the net CRE. Moreover, distinct CRE biases of the reanalyses occur in the Intertropical Convergence Zone （ITCZ）, coastal Pa- cific and Atlantic regions, and East Asia. Quantitative examination further indicates that the spatial correlations of CREs and TOA upward radiation fluxes with corre- sponding observations in ERA-Interim are better than in the other two reanalyses. Although MERRA has certain abilities in producing the magnitudes of global mean CREs, its performance in terms of spatial correlations in winter and summer are worse than for the other two re- analyses. The ability of JRA55 in reflecting CREs lies between the other two datasets. Compared to the global mean results, the spatial correlations of shortwave CRE in East Asia decrease and the biases of regional mean CREs increase in the three reanalyses. This implies that, cur- rently, it is still difficult to reproduce East Asian CREs based on these reanalyses. Relatively, ERA-Interim de- scribes the seasonal variation of East Asian CREs well, albeit weaker than observed. The present study also sug- gests that in-depth exploration of the ability of reanalysis data to describe aspects relating to cloud properties and rad- iation is needed usin~ more comprehensive observations.展开更多
基金supported jointly by the National Basic Research Program of China(Grant Nos.2012CB955303 and 2013CB955803)the Chinese Academy of Sciences Ocean Project(Grant No.XDA11010402)+1 种基金the National Natural Science Foundation of China(Grant Nos.41175059 and 41375087)the Key Laboratory of Meteorological Disaster of Ministry of Education(Nanjing University of Information Science and Technology)(Grant No.KLME1409)
文摘Cloud radiative effects （CREs） at the top of the atmosphere （TOA） in three reanalysis datasets （the Eur- opean Center for Medium-Range Weather Forecasts In- terim Reanalysis （ERA-Interim）, the Japanese 55-yr Re- analysis Project （JRA-55）, and the Modem-Era Retro- spective Analysis for Research and Applications （MERRA）） are evaluated using recent satellite-based observations. The reanalyses can basically capture the spatial pattern of the annual mean shortwave CRE, but the global mean longwave CRE in ERA-interim and JRA55 is weaker than observed, leading to overestimations of the net CRE. Moreover, distinct CRE biases of the reanalyses occur in the Intertropical Convergence Zone （ITCZ）, coastal Pa- cific and Atlantic regions, and East Asia. Quantitative examination further indicates that the spatial correlations of CREs and TOA upward radiation fluxes with corre- sponding observations in ERA-Interim are better than in the other two reanalyses. Although MERRA has certain abilities in producing the magnitudes of global mean CREs, its performance in terms of spatial correlations in winter and summer are worse than for the other two re- analyses. The ability of JRA55 in reflecting CREs lies between the other two datasets. Compared to the global mean results, the spatial correlations of shortwave CRE in East Asia decrease and the biases of regional mean CREs increase in the three reanalyses. This implies that, cur- rently, it is still difficult to reproduce East Asian CREs based on these reanalyses. Relatively, ERA-Interim de- scribes the seasonal variation of East Asian CREs well, albeit weaker than observed. The present study also sug- gests that in-depth exploration of the ability of reanalysis data to describe aspects relating to cloud properties and rad- iation is needed usin~ more comprehensive observations.
