Calibration effects of the net longwave radiation equation in Penman-type methods at Tateno, Japan
Calibration effects of the net longwave radiation equation in Penman-type methods at Tateno, Japan
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DOI：
10.3178/hrl.9.113
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发表时间：
2015
影响因子：
1.1
通讯作者：
Hiroyuki Matsui;K. Osawa
中科院分区：
文献类型：
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作者：
Hiroyuki Matsui;K. Osawa
彭曼型蒸散方法在灌溉用水管理和水资源规划中有着广泛的应用。为了利用Penmantype方法确定日参考ET，必须通过基于气象资料的经验净长波辐射方程来估算净长波辐射。本文给出了利用Tateno观测站的高精度观测资料对长波净辐射方程进行定标的系数。用这些校正系数计算的日净长波辐射与观测数据相比，与联合国粮食及农业组织(FAO)第56号灌溉和排水文件(FAO56-PM)中原始的Penman-Monteith方程的结果相比，更符合。特别是，FAO56-PM云量因子系数在本研究中得到了更有效的定标。通过校准的FAO56-PM计算的年平均参考ET大约相当于使用原始系数计算的值的90%。
Penman-type evapotranspiration (ET) methods are widely used in irrigation water management and water resource planning. To determine the daily reference ET using Penmantype methods, net longwave radiation must be estimated through an empirical net longwave radiation equation based on meteorological data. This paper presents the coefficients of the net longwave radiation equation calibrated using highly accurate data observed at the Tateno observatory, which belongs to the Baseline Surface Radiation Network (BSRN). The daily net longwave radiation calculated with these calibrated coefficients is in better agreement with the observed data as compared with those of the original Penman–Monteith equation in the Food and Agriculture Organization (FAO) Irrigation and Drainage Paper no. 56 (FAO56-PM). In particular, the FAO56-PM cloudiness factor coefficients are more effectively calibrated in this study. The annual mean reference ET calculated through the calibrated FAO56-PM corresponds to approximately 90% of the values calculated using the original coefficients.