Sensitivity of mixed-phase moderately deep convective clouds to parameterizations of ice formation – an ensemble perspective
Sensitivity of mixed-phase moderately deep convective clouds to parameterizations of ice formation – an ensemble perspective
复制标题
混合相中深对流云对冰形成参数化的敏感性——集合视角
DOI：
10.5194/acp-21-3627-2021
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发表时间：
2021
影响因子：
6.3
通讯作者：
P. Field
中科院分区：
文献类型：
--
作者：
A. Miltenberger;P. Field
摘要。云中冰的形成是混合相云和冰相云中一个重要的过程。然而，冰的形成在数值模式中的表现是高度不确定的。在过去的十年中，已经提出了几种新的非均质冻结参数化。目前还不清楚在数值天气预报中选择一种参数化而不是另一种参数化的影响。我们对中深对流云（英国西南部约~−18°C的云）进行了高分辨率模拟（Δx = 250 m），使用了几种冰形成公式，并将云场特性的变化与相同情况下初始条件集合的扩展进行了比较。改变冰的形成表征对水流星数量、浓度和质量混合比剖面的影响最大。虽然累积降水的变化在10%左右，但高降水率（第95百分位）的变化幅度为20%。使用不同的冰形成表示会使出射短波辐射在白天平均变化约2.9 W m−2。选择一种特殊的冰形成表示总是比完全忽略非均质冰形成的影响要小。排除Hallett-Mossop过程的表征或改变非均质冻结参数化对大多数云宏观和微物理变量的影响程度相似，但冻结的水流星质量混合比和数量浓度除外。与一个10元高分辨率初始条件集合的云性质分布的比较表明，水流星剖面对冰形成过程公式的敏感性大于对初始条件的敏感性。特别是，排除Hallet-Mossop表示会导致剖面明显不同于集合中的任何剖面。相比之下，集合扩展明显超过了使用不同冰形成表示在累积降水、降水速率、凝结水路径、云分数和向外辐射通量方面所带来的变化。
Abstract. The formation of ice in clouds is an important processes in mixed-phase and ice-phase clouds. Yet, the representation of ice formation in numerical models is highly uncertain. In the last decade several new parameterisations for heterogeneous freezing have been proposed. It is so far unclear what the effect of choosing one parameterisation over another is in the context of numerical weather prediction. We conducted high-resolution simulations (Δx = 250 m) of moderately deep convective clouds (cloud to about ~ −18 °C over the southwestern UK using several formulations of ice formation and compare the resulting changes in cloud field properties to the spread of a initial condition ensemble for the same case. The strongest impact of altering the ice formation representation is found in the hydrometeor number concentration and mass mixing ratio profiles. While change in accumulated precipitation are around 10 %, high precipitation rates (95th percentile) vary by 20. Using different ice formation representations changes the outgoing short-wave radiation by about 2.9 W m−2 averaged over daylight hours. The choice of a particular representation for ice formation has always a smaller impact then omitting heterogeneous ice formation completely. Excluding the representation of the Hallett–Mossop process or altering the heterogeneous freezing parameterisation has an impact of similar magnitude on most cloud macro- and microphysical variables with the exception of the frozen hydrometeor mass mixing ratios and number concentrations. A comparison to the spread of cloud properties in a 10-member high-resolution initial condition ensemble shows that the sensitivity of hydrometeor profiles to the formulation of ice formation processes is larger than sensitivity to initial conditions. In particular, excluding the Hallet–Mossop representation results in profiles clearly different from any in the ensemble. In contrast, the ensemble spread clearly exceeds the changes introduced by using different ice formation representations in accumulated precipitation, precipitation rates, condensed water path, cloud fraction and outgoing radiation fluxes.
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影响因子：
6.3
作者：
DeMott, P. J.;Prenni, A. J.;Kreidenweis, S. M.
通讯作者：
Kreidenweis, S. M.
冰核粒子的性质影响热带对流云系统的辐射特性
DOI：
10.5194/acp-2020-571
发表时间：
2020
期刊：
--
影响因子：
--
作者：
Hawker R
通讯作者：
Hawker R
DOI：
10.1175/amsmonographs-d-16-0014.1
发表时间：
2017-01-01
期刊：
ICE FORMATION AND EVOLUTION IN CLOUDS AND PRECIPITATION: MEASUREMENT AND MODELING CHALLENGES
影响因子：
--
作者：
Field, P. R.;Lawson, R. P.;Sullivan, S.
通讯作者：
Sullivan, S.
影响因子：
6.3
作者：
Glassmeier, Franziska;Hoffmann, Fabian;Feingold, Graham
通讯作者：
Feingold, Graham