An update on the 4D-LETKF data assimilation system for the whole neutral atmosphere

Koshin, Dai; Sato, Kaoru; Kohma, Masashi; Watanabe, Shingo

doi:https://doi.org/10.5194/gmd-15-2293-2022

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.

https://doi.org/10.5194/gmd-15-2293-2022

© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 15, issue 5

Development and technical paper

|

17 Mar 2022

Development and technical paper |

| 17 Mar 2022

An update on the 4D-LETKF data assimilation system for the whole neutral atmosphere

Dai Koshin, Kaoru Sato, Masashi Kohma, and Shingo Watanabe

Supplement

https://doi.org/10.5194/gmd-15-2293-2022-supplement

Data sets

NCEP ADP Global Upper Air and Surface Weather Observations (PREPBUFR format) NCEP ADP https://doi.org/10.5065/Z83F-N512

Aura MLS data M. Schwartz, N. Livesey, and W. Read https://doi.org/10.5067/Aura/MLS/DATA2021

MERRA-2 inst3_3d_asm_Np: 3d, 3-Hourly, Instantaneous, Pressure-Level, Assimilation, Assimilated Meteorological Fields V5.12.4 GMAO https://doi.org/10.5067/QBZ6MG944HW0

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.