Effects of clouds, ice sheet, and sea ice on the Earth radiation budget in the Antarctic
Effects of clouds, ice sheet, and sea ice on the Earth radiation budget in the Antarctic
复制标题
云、冰盖和海冰对南极地区地球辐射收支的影响
DOI：
--
复制
发表时间：
1997
期刊：
影响因子：
--
通讯作者：
T. Charlock
中科院分区：
文献类型：
--
作者：
T. Yamanouchi;T. Charlock
利用1987/1988年地球辐射平衡实验、国际卫星云气候学计划和特殊传感器微波/成像仪资料，研究了云、大陆冰盖和海冰对南极辐射收支的影响。由于海拔升高，大陆冰盖不仅影响反照率，而且还影响地表温度，从而影响出射长波辐射(OLR)。南极大陆的高海拔使两极地区的辐射收支不对称。在海拔2公里以下，OLR以5-10W/m~2/km的速度减小；在海拔2公里以上，OLR大约以20W/m~2/km的速度减小。海冰是一个关键的气候反馈因素，它对辐射的影响似乎比云小。在10月60°-65°S之间，海冰使大气层顶反照率增加约0.2，OLR值减少7-10W/m2，这似乎比正式的云强迫要小，后者使反照率增加0.3，OLR值减少30-40W/m2。然而，这些数字并不能完全区分海冰和云层的独立影响。更详细的分析表明，海冰的独立效应与云一样大，云将海冰的辐射效应掩盖了一半以上。
The effects of clouds, the continental ice sheet, and sea ice on the radiation budget in the Antarctic are examined by using Earth Radiation Budget Experiment, International Satellite Cloud Climatology Project, and special sensor microwave/imager data in 1987/1988. The continental ice sheet affects not only the albedo but also the surface temperature because of elevation and hence the outgoing longwave radiation (OLR). The high elevation of the Antarctic continent makes the radiation budget in both polar regions asymmetric. At elevations below 2 km the OLR is reduced at the rate of 5–10 W/m2/km; above 2 km the rate is about 20 W/m2/km. Sea ice, which is a critical climate feedback factor, appears to have less impact on radiation than do clouds. Between 60° and 65°S in October, sea ice increases the top of the atmosphere albedo by about 0.2 and reduces the OLR by 7–10 W/m2; this seems smaller than the formal cloud forcing, which increases the albedo by 0.3 and reduces the OLR by 30–40 W/m2. However, these numbers do not fully differentiate the independent effects of sea ice and cloudiness. A more detailed analysis shows that the independent effect of sea ice is as large as clouds, with clouds masking the radiative effect of sea ice by more than one half.