Strong control of Southern Ocean cloud reflectivity by ice-nucleating particles
Strong control of Southern Ocean cloud reflectivity by ice-nucleating particles
复制标题
冰核粒子对南大洋云反射率的强烈控制
DOI：
--
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发表时间：
2018
影响因子：
11.1
通讯作者：
K. Carslaw
中科院分区：
文献类型：
--
作者：
J. Vergara;A. Miltenberger;K. Furtado;D. Grosvenor;B. Shipway;A. Hill;J. Wilkinson;P. Field;B. Murray;K. Carslaw
与观测结果相比，南大洋上空的模拟云反射的太阳辐射太少，这导致模拟的表面温度和气候系统的许多其他重要特征存在误差。我们的研究结果表明，在气旋系统中最偏向的云类型的辐射特性是高度敏感的冰成核粒子的浓度。在这个偏远的海洋环境中，独特的低浓度冰成核颗粒强烈抑制降水，并使更明亮的云层得以维持。在南大洋上空云辐射特性的气候模式模拟中的大偏差导致模拟的海表面温度、大气环流和气候敏感性的大误差。在这里，我们将联合收割机云解析模型模拟与该地区冰成核颗粒浓度的估计相结合，以表明我们模拟的南大洋云反射的辐射远远超过全球模型预测的辐射，与卫星观测一致。具体来说，我们表明，云是最敏感的冰成核粒子的浓度是低级别的混合相云在寒冷的部门的热带气旋，以前已被确定为南大洋辐射偏差的主要贡献者。在南大洋上盛行的非常低的冰成核粒子浓度强烈地抑制了云滴的冻结，减少了降水，并增强了云的反射率。这些结果有助于解释为什么强烈的辐射偏差主要发生在远离冰核粒子主要来源的偏远地区。这些结果对气候模式提出了实质性的挑战，使其能够模拟现实的冰核粒子浓度及其在特定气象条件下的影响。
Significance Simulated clouds over the Southern Ocean reflect too little solar radiation compared with observations, which results in errors in simulated surface temperatures and in many other important features of the climate system. Our results show that the radiative properties of the most biased types of clouds in cyclonic systems are highly sensitive to the concentration of ice-nucleating particles. The uniquely low concentrations of ice-nucleating particles in this remote marine environment strongly inhibit precipitation and allow much brighter clouds to be sustained. Large biases in climate model simulations of cloud radiative properties over the Southern Ocean cause large errors in modeled sea surface temperatures, atmospheric circulation, and climate sensitivity. Here, we combine cloud-resolving model simulations with estimates of the concentration of ice-nucleating particles in this region to show that our simulated Southern Ocean clouds reflect far more radiation than predicted by global models, in agreement with satellite observations. Specifically, we show that the clouds that are most sensitive to the concentration of ice-nucleating particles are low-level mixed-phase clouds in the cold sectors of extratropical cyclones, which have previously been identified as a main contributor to the Southern Ocean radiation bias. The very low ice-nucleating particle concentrations that prevail over the Southern Ocean strongly suppress cloud droplet freezing, reduce precipitation, and enhance cloud reflectivity. The results help explain why a strong radiation bias occurs mainly in this remote region away from major sources of ice-nucleating particles. The results present a substantial challenge to climate models to be able to simulate realistic ice-nucleating particle concentrations and their effects under specific meteorological conditions.
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影响因子：
4.6
作者：
Hawcroft, Matt;Haywood, Jim M.;Stephens, Graeme
通讯作者：
Stephens, Graeme
影响因子：
5.1
作者：
Mann, G. W.;Carslaw, K. S.;Johnson, C. E.
通讯作者：
Johnson, C. E.
影响因子：
6.3
作者：
DeMott, P. J.;Prenni, A. J.;Kreidenweis, S. M.
通讯作者：
Kreidenweis, S. M.
DOI：
10.5194/gmd-2016-194-supplement
发表时间：
2017
期刊：
--
影响因子：
--
作者：
D. Walters;I. Boutle;M. Brooks;T. Melvin;R. Stratton;S. Vosper;H. Wells;K. Williams;N. Wood
通讯作者：
D. Walters;I. Boutle;M. Brooks;T. Melvin;R. Stratton;S. Vosper;H. Wells;K. Williams;N. Wood
飞机对南极半岛和拉森冰架上空云层内冰浓度的现场观测
影响因子：
6.3
作者：
Grosvenor D
通讯作者：
Grosvenor D