DOI: 10.1007/s00382-015-2693-z
Scopus记录号: 2-s2.0-84930813268
论文题名: Evaluation and intercomparison of clouds, precipitation, and radiation budgets in recent reanalyses using satellite-surface observations
作者: Dolinar E.K. ; Dong X. ; Xi B.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 46, 期: 2017-07-08 起始页码: 2123
结束页码: 2144
语种: 英语
英文摘要: Atmospheric reanalysis datasets offer a resource for investigating climate processes and extreme events; however, their uncertainties must first be addressed. In this study, we evaluate the five reanalyzed (20CR, CFSR, Era-Interim, JRA-25, and MERRA) cloud fraction (CF), precipitation rates (PR), and top-of-atmosphere (TOA) and surface radiation budgets using satellite observations during the period 03/2000–02/2012. Compared to the annual averaged CF of 56.7 % from CERES MODIS (CM) four of the five reanalyses underpredict CFs by 1.7– 4.6 %, while 20CR overpredicts this result by 7.4 %. PR from the Tropical Rainfall Measurement Mission (TRMM) is 3.0 mm/day and the reanalyzed PRs agree with TRMM within 0.1–0.6 mm/day. The shortwave (SW) and longwave (LW) TOA cloud radiative effects (CREtoa) calculated by CERES EBAF (CE) are −48.1 and 27.3 W/m2, respectively, indicating a net cooling effect of −20.8 W/m2. Of the available reanalysis results, the CFSR and MERRA calculated net CREtoa values agree with CE within 1 W/m2, while the JRA-25 result is ~10 W/m2 more negative than the CE result, predominantly due to the underpredicted magnitude of the LW warming in the JRA-25 reanalysis. A regime metric is developed using the vertical motion field at 500 hPa over the oceans. Aptly named the “ascent” and “descent” regimes, these areas are distinguishable in their characteristic synoptic patterns and the predominant cloud-types; convective-type clouds and marine boundary layer (MBL) stratocumulus clouds. In general, clouds are overpredicted (underpredicted) in the ascent (descent) regime and the biases are often larger in the ascent regime than in the descent regime. PRs are overpredicted in both regimes; however the observed and reanalyzed PRs over the ascent regime are an order of magnitude larger than those over the descent regime, indicating different types of clouds exist in these two regimes. Based upon the Atmospheric Radiation Measurement Program ground-based and CM satellite observations, as well as reanalyzed results, the annual CFs are 15 % higher at the Azores site than at the Nauru site (70.2 vs. 55.2 %), less SW radiation (~20 %) is transmitted the surface, and less LW radiation (~60 W/m2) is emitted back to the surface. Also, the seasonal variations in both CF and surface radiation fluxes are much smaller at the Nauru site than at the Azores site. The dichotomy between the atmospheric ascent and descent regimes is a good measure for determining which parameterization scheme requires more improvement (convective vs. MBL clouds) in these five reanalyses. © Springer-Verlag Berlin Heidelberg 2015.
资助项目: UND, University of North Dakota
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53688
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Atmospheric Science, University of North Dakota, 4149 University Ave. Stop 9006, Grand Forks, ND, United States
Recommended Citation:
Dolinar E.K.,Dong X.,Xi B.. Evaluation and intercomparison of clouds, precipitation, and radiation budgets in recent reanalyses using satellite-surface observations[J]. Climate Dynamics,2016-01-01,46(2017-07-08)