Method Development for Estimating Sensible Heat Flux over the Tibetan Plateau from CMA Data
Method Development for Estimating Sensible Heat Flux over the Tibetan Plateau from CMA Data
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DOI：
10.1175/2009jamc2167.1
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发表时间：
2009-12
影响因子：
3
通讯作者：
Kun Yang;J. Qin;Xiaofeng Guo;Degang Zhou;Yaoming Ma
中科院分区：
文献类型：
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作者：
Kun Yang;J. Qin;Xiaofeng Guo;Degang Zhou;Yaoming Ma
为了弄清青藏高原的热力强迫，中国气象局的长期粗时间分辨率资料在以往的许多研究中被广泛地用来估计地面感热通量，但这些估计很少与观测结果相比较。本研究首先针对西藏仪器流量数据对三种广泛使用的批量方案进行了评估。评估表明，这些方案估计的热通量存在很大的不确定性，特别是冬季向上的热通量可能被严重低估，因为没有考虑大气稳定度的日变化。为了提高估计精度，提出了一种新的方法，根据高分辨率实验数据得到的统计关系将高分辨率气象数据分解为每小时一次，然后用一个有效的通量方案从每小时数据中估算出感热通量。对夏季热通量观测和冬季净辐射观测的评估表明，新方法的效果比以往的方案要好得多，从而为量化西藏地表能量收支提供了可靠的基础。
To clarify the thermal forcing of the Tibetan Plateau, long-term coarse-temporal-resolution data from the China Meteorological Administration have been widely used to estimate surface sensible heat flux by bulk methods in many previous studies; however, these estimates have seldom been evaluated against observations. This study at first evaluates three widely used bulk schemes against Tibet instrumental flux data. The evaluation shows that large uncertainties exist in the heat flux estimated by these schemes; in particular, upward heat fluxes in winter may be significantly underestimated, because diurnal variations of atmospheric stability were not taken into account. To improve the estimate, a new method is developed to disaggregate coarse-resolution meteorological data to hourly according to statistical relationships derived from highresolution experimental data, and then sensible heat flux is estimated from the hourly data by a well-validated flux scheme. Evaluations against heat flux observations in summer and against net radiation observations in winter indicate that the new method performs much better than previous schemes, and therefore it provides a robust basis for quantifying the Tibetan surface energy budget.