Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature Variations
Ocean variability plays an essential role in the climate system at different time scales through air–sea interactions. Recent studies have addressed the importance of the ocean mixed layer in cooling feedback to tropical cyclones (TCs). However, using constant sea surface temperature (SST) in short-...
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doaj-ca0f47a023db4ff6be8f3bee6c97b7142021-09-25T23:43:15ZengMDPI AGAtmosphere2073-44332021-09-01121138113810.3390/atmos12091138Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature VariationsDiah Valentina Lestari0Xiaoming Shi1Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, ChinaDivision of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, ChinaOcean variability plays an essential role in the climate system at different time scales through air–sea interactions. Recent studies have addressed the importance of the ocean mixed layer in cooling feedback to tropical cyclones (TCs). However, using constant sea surface temperature (SST) in short-range weather forecasts remains common, especially in high-resolution regional models. This study investigates the role of subsurface ocean mixing in the short-range forecast of non-TC extreme rainfall with the Weather Research and Forecast (WRF) model. In the simulations of 26 heavy rainfall cases, we found that using a one-dimensional mixed layer model leads to a 15% enhancement (reduction) of rainfall maximum in six (two) cases compared to using constant SST. When the initial depth of the mixed layer model is perturbed by the amount of daily variability, 13 cases exhibit larger than 15% increases or decreases. A detailed analysis of one case suggests that the radiative process dominates the overall response of SST. The warming and moistening of boundary layer air cause significant strengthening of updrafts in convection. Although the SST change in most cases due to varying mixed layer model setups is less than 0.5 K, convective motions in some cases are surprisingly sensitive to small changes.https://www.mdpi.com/2073-4433/12/9/1138ocean mixed layerprecipitationshort-range forecastWRF-ARW |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Diah Valentina Lestari Xiaoming Shi |
spellingShingle |
Diah Valentina Lestari Xiaoming Shi Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature Variations Atmosphere ocean mixed layer precipitation short-range forecast WRF-ARW |
author_facet |
Diah Valentina Lestari Xiaoming Shi |
author_sort |
Diah Valentina Lestari |
title |
Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature Variations |
title_short |
Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature Variations |
title_full |
Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature Variations |
title_fullStr |
Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature Variations |
title_full_unstemmed |
Sensitivity of the Short-Range Precipitation Forecast in South China Region to Sea Surface Temperature Variations |
title_sort |
sensitivity of the short-range precipitation forecast in south china region to sea surface temperature variations |
publisher |
MDPI AG |
series |
Atmosphere |
issn |
2073-4433 |
publishDate |
2021-09-01 |
description |
Ocean variability plays an essential role in the climate system at different time scales through air–sea interactions. Recent studies have addressed the importance of the ocean mixed layer in cooling feedback to tropical cyclones (TCs). However, using constant sea surface temperature (SST) in short-range weather forecasts remains common, especially in high-resolution regional models. This study investigates the role of subsurface ocean mixing in the short-range forecast of non-TC extreme rainfall with the Weather Research and Forecast (WRF) model. In the simulations of 26 heavy rainfall cases, we found that using a one-dimensional mixed layer model leads to a 15% enhancement (reduction) of rainfall maximum in six (two) cases compared to using constant SST. When the initial depth of the mixed layer model is perturbed by the amount of daily variability, 13 cases exhibit larger than 15% increases or decreases. A detailed analysis of one case suggests that the radiative process dominates the overall response of SST. The warming and moistening of boundary layer air cause significant strengthening of updrafts in convection. Although the SST change in most cases due to varying mixed layer model setups is less than 0.5 K, convective motions in some cases are surprisingly sensitive to small changes. |
topic |
ocean mixed layer precipitation short-range forecast WRF-ARW |
url |
https://www.mdpi.com/2073-4433/12/9/1138 |
work_keys_str_mv |
AT diahvalentinalestari sensitivityoftheshortrangeprecipitationforecastinsouthchinaregiontoseasurfacetemperaturevariations AT xiaomingshi sensitivityoftheshortrangeprecipitationforecastinsouthchinaregiontoseasurfacetemperaturevariations |
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1717368221205528576 |