JRA-55CHS: An Atmospheric Reanalysis Produced with High-Resolution SST

• Masunaga Ryusuke

  Research Center for Advanced Science and Technology, The University of Tokyo Japan Society for the Promotion of Science

• Nakamura Hisashi

  Research Center for Advanced Science and Technology, The University of Tokyo

• Kamahori Hirotaka

  Meteorological Research Institute, Japan Meteorological Agency

• Onogi Kazutoshi

  Japan Meteorological Agency

• Okajima Satoru

  Research Center for Advanced Science and Technology, The University of Tokyo

Abstract

As an additional product of the Japanese 55-year Reanalysis (JRA-55) project, a new global atmospheric reanalysis product, named JRA-55CHS, is under construction. It utilizes quarter-degree sea-surface temperature (SST) as lower-boundary condition with the same data assimilation system as the JRA-55 Conventional (JRA-55C), into which no satellite data is assimilated. The SST data can resolve steep SST gradients along the western boundary currents (WBCs), which are not necessarily well represented in many of the other atmospheric reanalysis products, including the JRA-55C. The present paper briefly documents basic performance of the JRA-55CHS, through comparing it with the JRA-55C and satellite observations in focusing on the major WBC regions. In the JRA-55CHS, mesoscale atmospheric structures along the WBCs are well reproduced in their climatological-mean fields as captured in the satellite observations. Their interannual- to decadal-scale variations associated with SST variations are also reasonably reproduced. The corresponding atmospheric features are less obvious in the JRA-55C owing to smoother SST prescribed. Furthermore, comparison between the two reanalysis products reveals that the influence of frontal-scale SST distributions can reach into the middle and upper troposphere, especially in summer. The JRA-55CHS will be useful for deepening our understanding of the nature of midlatitude frontal-scale air-sea interactions.

Journal

• SOLA

  SOLA 14 (0), 6-13, 2018

  Meteorological Society of Japan

Keywords

• Atmospheric Science

Details

• CRID: 1390001205222070400
• NII Article ID: 130006315449
• DOI: 10.2151/sola.2018-002
• ISSN: 13496476
• Web Site: https://www.jstage.jst.go.jp/article/sola/14/0/14_2018-002/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed