Development of East Asia Regional Reanalysis based on advanced hybrid gain data assimilation method and evaluation with E3DVAR, ERA-5, and ERA-Interim reanalysis
<p>The East Asia Regional Reanalysis (EARR) system is developed based on the advanced hybrid gain data assimilation method (AdvHG) using the Weather Research and Forecasting (WRF) model and conventional observations. Based on EARR, the high-resolution regional reanalysis and reforecast fields...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-05-01
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| Series: | Earth System Science Data |
| Online Access: | https://essd.copernicus.org/articles/14/2109/2022/essd-14-2109-2022.pdf |
| Summary: | <p>The East Asia Regional Reanalysis (EARR) system is developed based on the
advanced hybrid gain data assimilation method (AdvHG) using the Weather Research
and Forecasting (WRF) model and conventional observations. Based on EARR,
the high-resolution regional reanalysis and reforecast fields are produced
with 12 km horizontal resolution over East Asia for 2010–2019. The newly
proposed AdvHG is based on the hybrid gain approach, weighting two different
analyses for an optimal analysis. The AdvHG differs from the hybrid
gain in that (1) E3DVAR is used instead of EnKF, (2) 6 h forecast of ERA5 is
used to be more consistent with WRF, and (3) the preexisting,
state-of-the-art reanalysis is used. Thus, the AdvHG can be regarded as an
efficient approach for generating regional reanalysis datasets thanks to cost
savings as well as the use of the state-of-the-art reanalysis. The upper-air
variables of EARR are verified with those of ERA5 for January and July 2017
and the 10-year period 2010–2019. For upper-air variables, ERA5
outperforms EARR over 2 years, whereas EARR outperforms (shows comparable
performance to) ERA-I and E3DVAR for January 2017 (July 2017). EARR represents precipitation better than ERA5 for January and July 2017.
Therefore, although the uncertainties of upper-air variables of EARR need to
be considered when analyzing them, the precipitation of EARR is more
accurate than that of ERA5 for both seasons. The EARR data presented
here can be downloaded from <span class="uri">https://doi.org/10.7910/DVN/7P8MZT</span>
(Yang and Kim, 2021b) for data on pressure levels and <span class="uri">https://doi.org/10.7910/DVN/Q07VRC</span> (Yang and Kim, 2021c) for precipitation.</p> |
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| ISSN: | 1866-3508 1866-3516 |