Modification of Near‐Surface Temperature Over East Asia Associated With Local‐Scale Paddy Irrigation
Modification of Near‐Surface Temperature Over East Asia Associated With Local‐Scale Paddy Irrigation
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DOI：
10.1029/2018jd029434
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
S. Sugimoto;H. Takahashi;H. Sekiyama
中科院分区：
文献类型：
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作者：
S. Sugimoto;H. Takahashi;H. Sekiyama
本研究使用两个区域气候模型实验来评估中国四川盆地的水稻灌溉对整个东亚近地表温度的影响：一个是对照实验（CTL 运行），用于使用未修改的地表方案计算土壤湿度；另一个是敏感性实验（SEN 运行），其中纳入了水稻生长季节开始时流域土壤湿度的增加。尽管 CTL 运行中四川盆地的近地表温度高于观测值，但由于与土壤湿度增加相关的鲍文比的变化，SEN 运行中近地表温度有所改善。在SEN运行中，由于与降水相关的云对流发生变化，流域局部尺度地表湿度的改变导致中国东北地区近地表温度相对于CTL运行降低，而华南地区近地表温度升高，进而改变了地表的太阳辐射和净辐射以及感热通量和潜热通量的分配。 SEN运行中与可降水量增加相关的温室效应也会影响中国东南部和日本西南部北部海洋的近地表变暖，这些地区的辐射过程和地表热通量对近地表温度的影响很小。因此，这些结果表明，四川盆地陆地表面湿度的局部变化导致东亚部分地区近地表温度空间分布的变化。
This study used two regional climate model experiments to assess the impact of paddy irrigation in the Sichuan Basin, China, on the near‐surface temperature across East Asia: a control experiment (CTL run), which was used to calculate soil moisture using an unmodified land surface scheme and a sensitivity experiment (SEN run) that incorporated an increase in soil moisture over the basin at the beginning of the rice‐growing season. Although the near‐surface temperature in the Sichuan Basin was higher in the CTL run than in the observations, it improved in the SEN run because of a change in the Bowen ratio associated with the increase in soil moisture. In the SEN run, the modification of local‐scale land surface wetness in the basin causes the decrease in the near‐surface temperature over northeastern China and its increase over southern China relative to that in the CTL run because of a change in the cloud convection associated with precipitation, which, in turn, modifies the solar and net radiation at the surface and the partitioning into the sensible and latent heat fluxes. The greenhouse effect associated with an increase in precipitable water in the SEN run also influences near‐surface warming over southeastern China and the ocean north of southwestern Japan, where the impacts of radiation processes and surface heat fluxes on the near‐surface temperature are small. Consequently, these results suggest that local‐scale modifications to land surface wetness in the Sichuan Basin result in changes in the spatial distribution of near‐surface temperatures over a part of East Asia.