Comparison of airborne measured and calculated spectral actinic flux and derived photolysis frequencies during the PEM Tropics B mission
Comparison of airborne measured and calculated spectral actinic flux and derived photolysis frequencies during the PEM Tropics B mission
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PEM Tropics B 任务期间机载测量和计算的光谱光化通量以及导出的光解频率的比较
DOI：
10.1029/2001jd001320
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发表时间：
2002
影响因子：
--
通讯作者：
S. Madronich
中科院分区：
文献类型：
--
作者：
R. Shetter;L. Cinquini;B. Lefer;S. Hall;S. Madronich
[1]扫描光化通量分光辐射计（SAFS）仪器安装在美国国家航空航天局（NASA）DC-8和P-3 B研究飞机上，用于热带太平洋的太平洋探索使命（PEM热带B使命）。SAFS仪器测量了282 - 420 nm波长范围内的上升流和下降流光化通量。从光化通量光谱，光解频率的一些分子进行了计算。PEM Tropics B使命期间的飞行轨迹在从地面到12公里的高度上变化，大部分时间花在上面、下面以及破碎和分散的云层中。比较测量的光解频率的光解频率计算与国家大气研究中心（NCAR）对流层紫外可见光（TUV）辐射传输模型，假设晴朗的天空，证明了一些预期的差异，在这个复杂的辐射环境，而在一般的测量和模型之间的协议是在15%以内。测量结果和模型之间的差异预计在云内和周围，因为辐射模型没有配备输入破碎和散射云的影响，除非在个别情况下。SAFS测量的总光解频率与TUV模型的综合平均比率的差异对于jNO 2为6%至18%，对于jO（1D）为6%至11%。测量值和模型之间的差异代表了在对流层有破碎和散射云的区域和全球大气化学模型中使用晴空辐射传输模型中的光解频率时可以预期的准确性。
[1] Scanning actinic flux spectroradiometer (SAFS) instruments were deployed on the National Aeronautics and Space Administration (NASA) DC-8 and P-3B research aircraft for the Pacific Exploratory Mission in the Tropical Pacific (PEM Tropics B mission). The SAFS instruments measured the wavelength-dependent downwelling and upwelling actinic flux from 282 to 420 nm. From the actinic flux spectra, photolysis frequencies of a number of molecules were calculated. Flight tracks during the PEM Tropics B mission varied in altitude from the surface up to 12 km, with much time spent above, below, and among broken and scattered clouds. Comparisons of the measured photolysis frequencies to the photolysis frequencies calculated with the National Center for Atmospheric Research (NCAR) tropospheric ultraviolet visible (TUV) radiative transfer model, assuming clear skies, demonstrate some expected differences in this complex radiation environment, while in general the agreement between the measurements and the model is within 15%. Differences between the measurements and the model are expected in and around clouds, because the radiation model is not equipped to input broken and scattered cloud effects, except on an individual case-by-case basis. The differences in the composite mean ratio of SAFS measurement to TUV model for total photolysis frequencies vary from 6% to 18% for jNO2 and from 6% to 11% for jO(1D) for both aircraft. The differences between the measurements and the models represent the accuracy that can be expected when using photolysis frequencies from clear-sky radiative transfer modeling in regional and global atmospheric chemistry models for regions with broken and scattered clouds in the troposphere.