Systematic evaluation of the impacts of GPSRO data on the prediction of typhoons over the northwestern Pacific in 2008–2010
In this paper, we perform a systematic evaluation of the impact of Global Positioning System radio occultation (GPSRO) data on typhoon-track prediction over the northwestern Pacific. Specifically, we perform data assimilation and forecast experiments using the Typhoon Weather Research and Forecastin...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-06-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/8/2531/2015/amt-8-2531-2015.pdf |
| Summary: | In this paper, we perform a systematic evaluation of the impact of Global
Positioning System radio occultation (GPSRO) data on typhoon-track
prediction over the northwestern Pacific. Specifically, we perform data
assimilation and forecast experiments using the Typhoon Weather Research and
Forecasting (TWRF) system at 45 km resolution on 11 typhoons (with a
total of 327 cases) in the period of 2008–2010 over the northwestern
Pacific, with or without the use of GPSRO refractivity observations. On
average, about 100 GPSRO soundings are assimilated over a 12 h partially
cycling assimilation period. The results indicate that the assimilation of
GPSRO data reduces the 72 h track forecast errors by approximately 12 km
(5 %). Although this is only a modest improvement, it is statistically
significant. The assimilation of GPSRO data improves the analysis and the
forecast of temperature, water vapor, and wind fields. Further analysis
shows that the reduction in typhoon-track forecast errors can be attributed
to the improved prediction of western Pacific subtropical high (WPSH) and
its associated circulation, which leads to better forecasting of the
environmental steering flow. |
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| ISSN: | 1867-1381 1867-8548 |