Impacts of Increased SST Resolution on the North Pacific Storm Track in ERA-Interim
- PDF / 2,798,568 Bytes
- 11 Pages / 595.3 x 841.9 pts (A4) Page_size
- 48 Downloads / 153 Views
• Original Paper •
Impacts of Increased SST Resolution on the North Pacific Storm Track in ERA-Interim Chao ZHANG1, Hailong LIU*2,3, Jinbo XIE2, Chongyin LI1,2, and Pengfei LIN2,3 1College 2State
of Meteorology and Oceanography, National University of Defense Technology, Nanjing 211101, China Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
3College
of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China (Received 24 March 2020; revised 3 July 2020; accepted 17 July 2020) ABSTRACT
This study examines the artificial influence of increasing the SST resolution on the storm track over the North Pacific in ERA-Interim. Along with the mesoscale oceanic eddies and fronts resolved during the high-resolution-SST period, the low-level storm track strengthens northward, reaching more than 30% of the maximum values in the low-resolution-SST period after removing the influence of ENSO. The mesoscale structure firstly imprints on the marine atmospheric boundary layer, which then leads to changes in turbulent heat flux and near-surface convergence, forcing a secondary circulation into the free atmosphere, strengthening the vertical eddy heat, momentum and specific humidity fluxes, and contributing to the enhancement of the storm track. Results from a high-resolution atmospheric model further indicate the changes in the storm track due to the mesoscale SST and their relationship. Key words: storm track, mesoscale SST, air−sea interaction, ERA-Interim, CAM4 Citation: Zhang, C., H. L. Liu, J. B. Xie, C. Y. Li, and P. F. Lin, 2020: Impacts of increased SST resolution on the North Pacific storm track in ERA-Interim. Adv. Atmos. Sci., 37(11), 1256−1266, https://doi.org/10.1007/s00376-020-0072-0. Article Highlights:
• Artificially increasing the SST resolution in ERA-Interim results in a northward strengthening of the storm track. • Due to resolving oceanic eddies, mesoscale imprints are found at the surface and the associated impact could penetrate into the free atmosphere.
• The results have important implications for determining the influence of SST resolution on the storm track and climate.
1. Introduction The European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim) dataset is typically applied to detect climate change (Chang and Yau, 2016), assess interannual or decadal variability (O’Reilly and Czaja, 2015; Wills and Thompson, 2018), or evaluate against model results (Piazza et al., 2016; Ma et al., 2017; Lee et al., 2018). However, the prescribed sea surface temperature (SST) resolution for the ERA-Interim analysis system has been increased twice since 1979, resulting in a significant impact on the marine atmospheric boundary layer (MABL) (Masunaga et al., 2015, 2016; Parfitt et al., 2017). Masunaga et al. (2015) noted that mesoscale features, such as surface wind convergence and cloudiness, can only be
Data Loading...
