An assessment of recent water vapor continuum measurements upon longwave and shortwave radiative transfer
An assessment of recent water vapor continuum measurements upon longwave and shortwave radiative transfer
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DOI：
10.1029/2010jd015505
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发表时间：
2011-10
影响因子：
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通讯作者：
D. Paynter;V. Ramaswamy
中科院分区：
文献类型：
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作者：
D. Paynter;V. Ramaswamy
[1]最近对水汽连续体的测量结合在一起，形成了一个被称为BPS连续体模型的经验连续体。这包括自连续谱的800-7500厘米−-1光谱区和外国连续谱的240-7300厘米−-1的大部分主要吸收光谱区。使用HITRAN数据库中的线数据，对三个标准试验大气中晴空条件下的长波(即地面辐射在1至3 000厘米−1之间的吸收/发射)和短波(即以太阳辐射为源，并考虑大气在1 000至17000厘米−1之间的吸收)进行了逐行辐射传输计算。这使得BPS可以与常用的CKD和MT CKD连续模型进行比较，此外还可以比以前在文献中提供的对自身和外部连续的单独作用进行更详细的研究。利用从多个实验研究获得的不确定度，有可能估计由于许多光谱区域的连续体而产生的影响的上限和下限。三种连续介质模式计算的中纬度夏季大气出射长波辐射均在0.6Wm−2以内，不确定度为±1.1Wm−2。相应的地面下涌辐射为1.3Wm−2±2.5Wm−2。对于短波吸收，不同模型的一致性在1.0%以内，估计不确定度为±1.7%。然而，这三个模型在自身和外来连续介质对短波吸收的贡献程度上有所不同。
[1] Recent measurements of the water vapor continuum have been combined to form an empirical continuum termed the BPS continuum model. This covers the 800 to 7500 cm−1 spectral region for the self continuum and most of the major absorbing spectral regions between 240 and 7300 cm−1 for the foreign continuum. Longwave (i.e., absorption/emission of terrestrial radiation between 1 and 3000 cm−1) and shortwave (i.e., using solar radiation as a source and considering atmospheric absorption between 1000 and 17000 cm−1) line by line (LBL) radiative transfer calculations have been performed for clear-sky conditions in three standard test atmospheres using line data from the HITRAN database. This has allowed BPS to be compared to the commonly used CKD and MT CKD continuum models, in addition to conducting a more detailed investigation of the separate roles of the self and foreign continua than previously provided in the literature. Using uncertainties obtained from multiple experimental studies it has been possible to estimate the upper and lower limits of the effects due to the continuum in many spectral regions. The outgoing longwave radiation in a midlatitude-summer (MLS) atmosphere calculated by all three continuum models agree to within 0.6 Wm−2 with a ±1.1 Wm−2 estimated uncertainty. The corresponding values for surface downwelling radiation are 1.3 Wm−2 ± 2.5 Wm−2. For shortwave absorption, the different models agree within 1.0%, with an estimated uncertainty of ±1.7%. However, the three models differ in the amount by which the self and foreign continua contribute to shortwave absorption.