Numerical integration errors in calculated tropospheric photodissociation rate coefficients
Numerical integration errors in calculated tropospheric photodissociation rate coefficients
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DOI：
10.1007/bf00053864
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发表时间：
1990-04
影响因子：
2
通讯作者：
S. Madronich;G. Weller
中科院分区：
文献类型：
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作者：
S. Madronich;G. Weller
采用高光谱分辨率（0.1 mm波长增量）计算了NO2、O3、HNO 2、CH 2 O和CH 3CHO的对流层光解离速率系数（J值），并与数值退化分辨率（Δλ=1，2，4，6，8和10 nm，以及几种常用的非均匀网格）得到的J值进行了比较。根据分子的不同，较大的增量可能会引入相当大的误差。因此，对于Δλ=10 nm，NO2的误差小于1%，HNO 2的误差小于2%，CH 2 O的误差为+6.5%至-16%，CH 3CHO的误差为-6.9%至+24%，O3的误差为-24%至+110%。对CH_2 O的误差主要来自于其吸收光谱的精细结构，且一般为负值（低估J）。O3的错误，并在较小程度上为CH 3CHO，主要来自下解决的重叠的分子作用光谱和对流层光化通量在平流层臭氧衰减的波长区域。这些误差的符号取决于光化通量是在辐射传递计算之前还是之后被平均到网格上。在所研究的所有情况下，Δλ≤2 nm的网格产生的误差不大于5%。
Tropospheric photodissociation rate coefficients (Jvalues) were calculated for NO2, O3, HNO2, CH2O, and CH3CHO using high spectral resolution (0.1 mm wavelength increments), and compared to theJvalues obtained with numerically degraded resolution (Δλ=1, 2, 4, 6, 8, and 10 nm, and several commonly used nonuniform grids). Depending on the molecule, substantial errors can be introduced by the larger increments. Thus for Δλ=10 nm, errors are less than 1% for NO2, less than 2% for HNO2, +6.5% to -16% for CH2O, -6.9% to +24% for CH3CHO, and -24% to +110% for O3. The errors for CH2O arise from the fine structure of its absorption spectrum, and are prevalently negative (underestimate ofJ). The errors for O3, and to a lesser extent for CH3CHO, arise mainly from under-resolving the overlap of the molecular action spectrum and the tropospheric actinic flux in the wavelength region of stratospheric ozone attenuation. The sign of those errors depends on whether the actinic flux is averaged onto the grid before or after the radiative transfer calculation. In all cases studied, grids with Δλ≤2 nm produced errors no larger than 5%.