Reconsidering the Quality and Utility of Downscaling

Journal of the Meteorological Society of Japan. Ser. II

Izuru TAKAYABU³  Hans von STORCH²  Jens Hesselbjerg CHRISTENSEN⁴  Hideki KANAMARU⁵  Koji DAIRAKU¹  Rasmus BENESTAD⁶ 

[1] National Research Institute for Earth Science and Disaster Prevention, Tsukuba, Japan;Institute of Coastal Research, Helmholtz Zentrum Geesthacht für Material- und Küstenforschung, Geesthacht, Germany;Meteorological Research Institute, Tsukuba, Japan;Danish Meteorological Institute, Copenhagen, Denmark;Food and Agriculture Organization of the United Nations, Rome, Italy;The Norwegian Meteorological Institute, Oslo, Norway

关键词: dynamical downscaling;    empirical statistical downscaling;    ensemble experiments;    skillful scale;    uncertainty;   

DOI  :  10.2151/jmsj.2015-042

学科分类：大气科学

来源: Meteorological Society of Japan

【 摘 要 】

 Dynamical downscaling (DDS) is performed using regional climate models (RCMs) with global atmospheric states as the input, but there is no consensus among researchers on how to define and estimate the resolvable scale of the various climatic variables obtained by DDS. Sources of RCM uncertainties, including both internal model and intermodel variability, have been assessed by performing ensemble simulations and model intercomparisons, sometimes under the controversial assumption that model bias is independent of the climatic state. Compared with low-resolution global climate simulations, DDS can add value in several ways. For example, because they consider high-resolution topographic data, RCMs can often capture mesoscale phenomena and can better represent climate dynamics. Another downscaling method, empirical statistical downscaling (ESD), is complementary to DDS because it is based on a different philosophy (i.e., sources of information) and on a mostly different set of assumptions. More collaboration and communication should be encouraged among those who develop models, those who use models and perform downscaling, those who use downscaling data, and those who make decisions based on the scientific results provided by models. In addition, ensemble experiments should be devised that can more effectively benefit impact studies. Using DDS and ESD, separately or in combination, users can maximize the utility of local climate information.

【 授权许可】

Unknown