Articles | Volume 15, issue 5
https://doi.org/10.5194/gmd-15-2293-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gmd-15-2293-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
An update on the 4D-LETKF data assimilation system for the whole neutral atmosphere
Department of Earth Planetary Science, The University of Tokyo,
Tokyo, 1130033, Japan
Kaoru Sato
Department of Earth Planetary Science, The University of Tokyo,
Tokyo, 1130033, Japan
Masashi Kohma
Department of Earth Planetary Science, The University of Tokyo,
Tokyo, 1130033, Japan
Shingo Watanabe
Japan Agency for Marine-Earth Science and Technology, Yokohama,
2360001, Japan
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The spatial pattern of subseasonal variability of the Asian monsoon anticyclone (AMA) is analyzed using long-term reanalysis data, integrating two different views using potential vorticity and the geopotential height anomaly. This study provides a link between two existing description of the Asian monsoon anticyclone, which is important for the understanding of the whole life cycle of its characteristic subseasonal variability pattern.
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Short summary
The 4D ensemble Kalman filter data assimilation system for the whole neutral atmosphere has been updated. The update includes the introduction of a filter to reduce the generation of spurious waves, change in the order of horizontal diffusion of the forecast model to reproduce more realistic tidal amplitudes, and use of additional satellite observations. As a result, the analysis performance has been greatly improved, even for disturbances with periods of less than 1 d.
The 4D ensemble Kalman filter data assimilation system for the whole neutral atmosphere has been...