MODIS-driven estimation of terrestrial latent heat flux in China based on a modified Priestley–Taylor algorithm |
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出 版 社：Agricultural and Forest Meteorology |
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发表时间：2013 |
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台 站：鼎湖山森林生态系统定位研究站 |
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作 者：周国逸（13），李跃林（14）
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点 击 率：565164 |
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关 键 字(英文)：Latent heat flux,Evapotranspiration,Priestley–Taylor,MODIS,China |
| 摘 要(英文)：Because of China’s large size, satellite observations are necessary for estimation of the land surface latent heat flux (LE). We describe here a satellite-driven Priestley–Taylor (PT)-based algorithm constrained by the Normalized Difference Vegetation Index (NDVI) and Apparent Thermal Inertia (ATI) derived from temperature change over time. We compare to the satellite-driven PT-based approach, PT-JPL, and validate both models using data collected from 16 eddy covariance flux towers in China. Like PT-JPL, our proposed algorithm avoids the computational complexities of aerodynamic resistance parameters. We run the algorithms with monthly Moderate Resolution Imaging Spectroradiometer (MODIS) products(0.05◦ resolution), including albedo, Land Surface Temperature (LST), surface emissivity, and NDVI; and,Insolation from the Japan Aerospace Exploration Agency (JAXA). We find good agreement between our estimates of monthly LE and field-measured LE, with respective Root Mean Square Error (RMSE) and bias differences of 12.5Wm−2 and
−6.4Wm−2. As compared with PT-JPL, our proposed algorithm has higher
correlations with ground-measurements. Between 2001 and 2010, LE shows generally negative trends in most regions of China, though positive LE trends occur over 39% of the region, primarily in Northeast,North and South China. Our results indicate that the variations of terrestrial LE are responding to large-scale droughts and afforestation caused by human activity with direct links to terrestrial energy exchange, both spatially and temporally. |
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 周国逸13-2013-Agricultural and Forest Meteorology-MODIS-driven estimation of terrestrial latent heat flux in China based on a modified Priestley–Taylor algorithm.pdf |
