The JRA-55 Reanalysis: Representation of Atmospheric Circulation and Climate Variability

By Y. Harada, H. Kamahori, C. Kobayashi, H. Endo, Shinya Kobayashi, Yukinari Ota, Hirokatsu Onoda, K. Onogi, Kengo Miyaoka, Kiyotoshi Takahashi. 2016

459 citations recorded by the source corpus.

This study investigates the quality of the Japanese 55-year Reanalysis (JRA-55), which is the second global reanalysis constructed by the Japan Meteorological Agency (JMA), by comparing it with other reanalyses and observational datasets. Improvements were found in the representation of atmospheric circulation on an isentropic surface and in the consistency of momentum budget based on the mass-weighted isentropic zonal mean method. The representation of climate variability in several regions was also examined. In the tropics, the frequencies of high spatial correlations with precipitation, which were estimated using the Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis, are clearly higher in JRA-55 than in JRA-25. The results indicate that JRA-55 generally improved the representations of phenomena on a wide range of space–time scales, such as equatorial waves, and transient eddies in the storm track regions, compared with JRA-25 during the satellite era. Moreover, JRA-55 improved the temporal consistency compared with the older reanalyses throughout the reanalysis period. In the stratosphere, we found larger discrepancies between reanalyses for the extra-tropical stratosphere during the Southern Hemisphere (SH) winter. Comparisons with radiosonde temperature revealed that JRA-55 has a smaller bias in temperature than the other reanalyses in the extra-tropical SH winter before 1979. Some issues in JRA-55 were also identified. The amplitude of equatorial waves and Madden–Julian oscillation in JRA-55 are weaker than in the other reanalyses. JRA-55 shows unrealistic strong cooling in South America and Australia, although the spatial distribution of the long-term temperature trends in JRA-55 is the closest to an observational dataset of global historical surface temperature.

Subfields: Atmospheric Science, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/7e4b0a65334652115eafacbfbb7a56c28e4edda8

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In Atmospheric Science

1. Gokhan Danabasoglu
2. S. Yeager
3. C. Böning
4. W. Large
5. S. Griffies
6. M. Bentsen
7. R. Small
8. Eric P. Chassignet

In Global and Planetary Change

1. S. Yeager
2. Gokhan Danabasoglu
3. S. Griffies
4. M. Bentsen
5. R. Small
6. Eric P. Chassignet
7. Simona Masina
8. Enrique Curchitser

Citations in the corpus

• A diagram for evaluating multiple aspects of model performance in simulating vector fields (2016, background): “, 2007), and JRA55 (Kobayashi et al., 2015; Harada et al., 2016) are observational data here.”
• JRA-55 based surface dataset for driving ocean–sea-ice models (JRA55-do) (2018, background): “JRA-55 (Kobayashi et al., 2015; Harada et al., 2016) is the first comprehensive reanalysis covering the last half-century since the European Center for Medium-Range Weather Forecast’s 45-year Reanalysis (ERA-40; Uppala et al.”