气候变化领域集成服务门户(CCPortal): Differences in tropical high clouds among reanalyses: Origins and radiative impacts

CCPortal

DOI	10.5194/acp-20-8989-2020
	Differences in tropical high clouds among reanalyses: Origins and radiative impacts
	S. Wright J.; Sun X.; Konopka P.; Krüger K.; Legras B.; M. Molod A.; Tegtmeier S.; J. Zhang G.; Zhao X.
发表日期	2020
ISSN	1680-7316
起始页码	8989
结束页码	9030
卷号	20 期号:14
英文摘要	We examine differences among reanalysis high-cloud products in the tropics, assess the impacts of these differences on radiation budgets at the top of the atmosphere and within the tropical upper troposphere and lower stratosphere (UTLS), and discuss their possible origins in the context of the reanalysis models. We focus on the ERA5 (fifth-generation European Centre for Medium-range Weather Forecasts - ECMWF - reanalysis), ERA-Interim (ECMWF Interim Reanalysis), JRA-55 (Japanese 55-year Reanalysis), MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications, Version 2), and CFSR/CFSv2 (Climate Forecast System Reanalysis/Climate Forecast System Version 2) reanalyses. As a general rule, JRA-55 produces the smallest tropical high-cloud fractions and cloud water contents among the reanalyses, while MERRA-2 produces the largest. Accordingly, long-wave cloud radiative effects are relatively weak in JRA-55 and relatively strong in MERRA-2. Only MERRA-2 and ERA5 among the reanalyses produce tropical-mean values of outgoing long-wave radiation (OLR) close to those observed, but ERA5 tends to underestimate cloud effects, while MERRA-2 tends to overestimate variability. ERA5 also produces distributions of long-wave, short-wave, and total cloud radiative effects at the top of the atmosphere that are very consistent with those observed. The other reanalyses all exhibit substantial biases in at least one of these metrics, although compensation between the long-wave and short-wave effects helps to constrain biases in the total cloud radiative effect for most reanalyses. The vertical distribution of cloud water content emerges as a key difference between ERA-Interim and other reanalyses. Whereas ERA-Interim shows a monotonic decrease of cloud water content with increasing height, the other reanalyses all produce distinct anvil layers. The latter is in better agreement with observations and yields very different profiles of radiative heating in the UTLS. For example, whereas the altitude of the level of zero net radiative heating tends to be lower in convective regions than in the rest of the tropics in ERA-Interim, the opposite is true for the other four reanalyses. Differences in cloud water content also help to explain systematic differences in radiative heating in the tropical lower stratosphere among the reanalyses. We discuss several ways in which aspects of the cloud and convection schemes impact the tropical environment. Discrepancies in the vertical profiles of temperature and specific humidity in convective regions are particularly noteworthy, as these variables are directly constrained by data assimilation, are widely used, and feed back to convective behaviour through their relationships with thermodynamic stability. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	atmospheric convection; atmospheric modeling; cloud radiative forcing; cloud water; data assimilation; radiation budget; tropical environment
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/247613
作者单位	Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing, China; Forschungszentrum Jülich (IEK-7: Stratosphere), Jülich, Germany; Department of Geosciences, University of Oslo, Oslo, Norway; Laboratoire de Météorologie Dynamique, Umr Cnrs 8539, Ipsl, PSL-ENS/Sorbonne Université/École Polytechnique, Paris, France; Global Modeling and Assimilation Office, Nasa Goddard Space Flight Center, Greenbelt, MD, United States; Institute of Space and Atmospheric Studies, University of Saskatchewan, Saskatoon, Canada; Scripps Institution of Oceanography, San Diego, CA, United States; Department of Atmospheric Sciences, Texas AĝandĝM University, College Station, TX, United States
推荐引用方式 GB/T 7714	S. Wright J.,Sun X.,Konopka P.,et al. Differences in tropical high clouds among reanalyses: Origins and radiative impacts[J],2020,20(14).
APA	S. Wright J..,Sun X..,Konopka P..,Krüger K..,Legras B..,...&Zhao X..(2020).Differences in tropical high clouds among reanalyses: Origins and radiative impacts.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(14).
MLA	S. Wright J.,et al."Differences in tropical high clouds among reanalyses: Origins and radiative impacts".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.14(2020).