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首页> 外文期刊>Journal of Geophysical Research. Biogeosciences >CALCULATION OF SURFACE AND TOP OF ATMOSPHERE RADIATIVE FLUXES FROM PHYSICAL QUANTITIES BASED ON ISCCP DATA SETS .2. VALIDATION AND FIRST RESULTS
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CALCULATION OF SURFACE AND TOP OF ATMOSPHERE RADIATIVE FLUXES FROM PHYSICAL QUANTITIES BASED ON ISCCP DATA SETS .2. VALIDATION AND FIRST RESULTS

机译：基于ISCCP数据集的物理量大气辐射通量的表面和顶部的计算2。验证和第一结果

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We use global, multiyear observations of the properties of clouds, the atmosphere, and the surface to calculate global shortwave (SW) and longwave (LW) fluxes at the top of the atmosphere and at the surface at a resolution of 280 km and 3 hours for every third month from April 1985 to January 1989. Our validation studies suggest that the specification of cloud effects is no longer the dominant uncertainty in reconstructing the radiative fluxes at the top of atmosphere and at the surface. Rather cloud property uncertainties are now roughly equal contributors to the flux uncertainty, along with surface and atmospheric properties. Overall, the estimated uncertainties in regional, monthly mean fluxes, based on comparisons to more direct measurements, are as follows: for S up arrow(t), 11 W/m(2) bias with a rms scatter of 7 W/m(2) (the bias may be as little as 5 W/m(2)); for L up arrow(t), -1 W/m(2) bias with a rms scatter of 4 W/m(2); for S down arrow(s), 10 - 20 W/m(2) bias with a rms scatter of 10 - 15 W/m(2) (the bias may only be approximate to 10 W/m(2) caused by aerosols); for ST, approximate to 3 W/m(2) bias with a rms scatter of 10 W/m(2); for L down arrow(s), probably < 15 W/m(2) bias (but with variable sign) with a rms scatter of 15 W/m(2) (bias and scatter depend most on atmospheric temperature uncertainties); and for LT less than or similar to 12 W/m(2) and < 24 W/m(2) for combined bias and scatter over oceans and land, respectively (very sensitive to surface temperature determinations). The resulting SW and LW flux data sets suggest the following conclusions: (1) The net SW heating of Earth appears predominantly at the surface, whereas the net LW cooling arises predominantly from the atmosphere. The net cooling effect of clouds on top of atmospheric radiation appears primarily at the surface rather than in the atmosphere. (2) Clouds have almost no net effect on the global mean radiation balance of the atmosphere, but they enhance the latitudinal gradient in the LW cooling and reinforce the radiative forcing for the mean atmospheric circulation. Clouds act to mute seasonal contrasts however. (3) Clouds enhance the land-ocean contrasts of the atmospheric cooling, reinforcing the growth of standing eddy motions; but reduce land-ocean contrasts of the surface heating. [References: 81]
机译：我们使用对云，大气和地表性质的全球多年观测数据，以280 km和3小时的分辨率计算大气顶部和地表的全球短波（SW）和长波（LW）通量从1985年4月到1989年1月的每三个月进行一次。我们的验证研究表明，在重建大气顶部和地表的辐射通量时，云效应的规范不再是主要的不确定性。确切地说，云特性的不确定性以及地表和大气特性对通量不确定性的贡献大致相等。总体而言，基于与更直接测量的比较，区域平均月通量的估计不确定性如下：对于S向上箭头（t），偏差为11 W / m（2），均方根值为7 W / m（ 2）（偏差可能低至5 W / m（2））;对于L向上箭头（t），-1 W / m（2）偏置，均方根散射为4 W / m（2）;对于S向下箭头，均方根散射为10-15 W / m（2）的均方根误差为10-20 W / m（2）（该偏置可能仅近似于由气溶胶引起的10 W / m（2） ）;对于ST，均方根散射为10 W / m（2）时约为3 W / m（2）偏置;对于L向下箭头，可能是<15 W / m（2）偏差（但具有可变符号），且均方根散射为15 W / m（2）（偏差和散射大部分取决于大气温度的不确定性）;对于LT而言，分别在海洋和陆地上的组合偏差和散射（小于或等于12 W / m（2）和<24 W / m（2））（对地表温度非常敏感）。由此产生的SW和LW通量数据集得出以下结论：（1）地球的净SW加热主要出现在地表，而净LW冷却主要来自大气。云对大气辐射的净冷却作用主要出现在地表而不是大气中。 （2）云对大气的全球平均辐射平衡几乎没有净影响，但它们会增加低气压冷却中的纬度梯度，并增强平均大气环流的辐射强迫。但是，云起到了减弱季节性差异的作用。 （3）云层增强了大洋与大气冷却的对比，增强了站立涡旋运动的增长;但可以降低地面加热的海洋对比。 [参考：81]

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