Estimation of daily maximum and minimum air temperature using MODIS land surface temperature products
Estimation of daily maximum and minimum air temperature using MODIS land surface temperature products
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DOI：
10.1016/j.rse.2012.10.034
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发表时间：
2013-03
影响因子：
13.5
通讯作者：
Wenbin Zhu;Aifeng Lű;S. Jia
中科院分区：
文献类型：
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作者：
Wenbin Zhu;Aifeng Lű;S. Jia
准确估计空间分布的气温（Ta）对于水文学、气象学和生态学等学科都有重要意义。中分辨率成像光谱仪（MODIS）的陆面温度（Ts）产品具有获得高时间（日）和空间分辨率（1 km）的全球陆面温度空间估计的潜力。以青藏高原北部香日德河流域为例，研究了利用Terra和Aqua卫星的MODIS Ts数据反演高分辨率Ta的可能性。统计分析结果表明，夜间Terra卫星上的MODIS Ts资料对日最低气温的估计值较好，RMSE=2.97°C，MAE=2.37°C，r=0.94;白天Terra卫星上的MODIS Ts资料与日最高气温的估计值差异较大，RMSE=7.45°C，MAE=6.21°C，r=0.83。为了提高日最高气温的估算精度，本文采用了温度植被指数（TVX）方法。通过将归一化植被指数（NDVI）与Ts的负相关系数阈值降低至-0.1，首次将TVX方法应用于MODIS陆地产品，成功地估算了日最高气温。验证结果表明，TVX方法显著提高了日最高气温的精度，RMSE=3.79°C，MAE=3.03°C，r=0.83。最后，利用一个简单的正弦曲线模式模拟了21：00-9：00 UCT期间的气温日变化。模拟结果与观测值吻合良好，RMSE=3.43°C，MAE=2.54°C，r=0.86。研究结果表明，利用TVX方法可以有效地从MODIS陆面产品中反演日最高和最低气温。
Accurate estimation of spatially distributed air temperature (Ta) is useful for a wide range of disciplines such as hydrology, meteorology and ecology. Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (Ts) products hold the potential to get spatial estimates of land surface temperature at high temporal (daily) and spatial resolution (1km) across the world. In this paper, the possibility of retrieving high-resolution Ta data from MODIS Ts data on both Terra and Aqua satellites was investigated over Xiangride River basin in the north Tibetan Plateau. The results of statistical analysis show that during the night MODIS Ts data on Terra satellite provides a good estimation of daily minimum air temperature with RMSE=2.97°C, MAE=2.37°C, and r=0.94, while during the day the difference between Terra MODIS Ts data and daily maximum air temperature is large with RMSE=7.45°C, MAE=6.21°C, and r=0.83. In order to improve the accuracy of the estimation of daily maximum air temperature, the temperature-vegetation index (TVX) method was used in this paper. By lowering the threshold for the negative correlation coefficient between NDVI (Normalized Difference Vegetation Index) and Ts to −0.1, the TVX method was applied to MODIS land products to estimate daily maximum air temperature successfully for the first time. The validation results show that the TVX method has improved the accuracy of daily maximum air temperature significantly with RMSE=3.79°C, MAE=3.03°C, and r=0.83. Finally, the diurnal air temperature variation was simulated using a simple sine curve model for the period 21:00–9:00UCT. The simulation results were in good agreement with observed values with RMSE=3.43°C, MAE=2.54°C, and r=0.86. The results of this study show that daily maximum and minimum air temperature can be retrieved effectively from MODIS land surface products through the use of TVX method.