A diagnostic study of future evaporation changes projected in CMIP5 climate models
A diagnostic study of future evaporation changes projected in CMIP5 climate models
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DOI：
10.1007/s00382-014-2087-7
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发表时间：
2014-02
期刊：
影响因子：
4.6
通讯作者：
A. Laîné;H. Nakamura;K. Nishii;T. Miyasaka
中科院分区：
文献类型：
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作者：
A. Laîné;H. Nakamura;K. Nishii;T. Miyasaka
气候平均降水蒸发差（P-E）在全球变暖的背景下，主要通过增加水分饱和度而增大。本研究的重点是蒸发量的变化，全球变暖和其依赖于直接变暖的影响，未来的预测的基础上，从耦合模式相互比较项目第5阶段（CMIP 5）。在大多数热带、亚热带和中纬度地区，地表温度升高的直接贡献被认为是蒸发量预计增加的主要原因。然而，这种影响被减弱的地面风和增加的近地面相对湿度的影响部分抵消，特别是在海洋上。地表空气比海面温度更高，也会通过降低交换系数和地表湿度对比度来减少地表蒸发。虽然一般来说，这种贡献是次要的，但在副极地海洋中，这种贡献是主导因素。在极地海洋上，海冰退缩的影响主要是在冬季的蒸发增加，而减少交换系数和表面湿度对比度加上海冰退缩占了大部分的响应在夏季。在各大洲，地表交换系数的变化反映了土壤湿度和植被等因素的变化，对调节变暖和地表空气相对湿度普遍降低的直接影响很重要。
It has been pointed out that climatological-mean precipitation-evaporation difference (P–E) should increase under global warming mainly through the increasing saturation level of moisture. This study focuses on evaporation changes under global warming and their dependency on the direct warming effect, on the basis of future projections from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Over most of the tropical, subtropical and midlatitude regions, the direct contribution from surface temperature increase is found to dominate the projected increase in evaporation. This contribution is nevertheless offset partially, especially over the oceans, by contributions from weakening surface winds and increasing near-surface relative humidity. Greater warming of surface air than of the sea surface also acts to reduce surface evaporation, by reducing both the exchange coefficient and humidity contrast at the surface. Though generally of secondary importance, this contribution is the dominant factor over the subpolar oceans. Over the polar oceans, the effect of sea-ice retreat dominantly contributes to the evaporation increase in winter, whereas the reduced exchange coefficient and surface humidity contrast coupled with the sea-ice retreat account for most of the response during summertime. Over the continents, changes in the surface exchange coefficient, reflecting changes in soil moisture and vegetation among other factors, are important to modulate the direct effects of the warming and the generally reduced surface air relative humidity.