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1.
So-Young Kim Ji-Young Han In-Jin Choi Soo Ya Bae 《Asia-Pacific Journal of Atmospheric Sciences》2014,50(4):469-480
Cloud and precipitation parameterization schemes are evaluated, and their sensitivity to the method and/or parameters used to determine cloud physical processes is examined using a singlecolumn version of the Unified Model (SCUM). In the experiment for TWP-ICE, cloud fraction is overestimated (underestimated) in the upper (lower) troposphere due to the wet (dry) bias. The precipitation rate is well simulated during the active monsoon period, but overestimated during the suppressed monsoon and clear skies periods. In the moist convection scheme, trigger condition and entrainment process affect the lower tropospheric humidity through the impact on convective occurrence frequency and intensity, respectively. Strengthening the trigger condition and using the adaptive entrainment method alleviate the low-level dry bias. In the microphysics scheme, more large-scale precipitation is produced with prognostic rain, due to rain sedimentation considering vertical velocity of rain drop, than with diagnostic rain. Less ice/snow deposition with the prognostic two-ice category results in lower ice water content and upper-level cloud fraction than with the diagnostic splitting method for the twoice category. In the cloud macrophysics scheme, the prognostic cloud fraction and cloud/ice water content scheme produces a larger cloud fraction and more cloud/ice water content than the diagnostic scheme, mainly due to detrainment from moist convection (cloud source) that surpasses the effect of convective heating and drying (cloud sink). This affects temperature by influencing the radiative, convective, and microphysical processes. The experiment with combined modifications in cloud and precipitation schemes shows that interaction between modified moist convection and cloud macrophysics schemes results in more alleviation of the cold bias not only at the lower levels but also at the upper levels. 相似文献
2.
The effects of sea surface temperature (SST), radiation, cloud microphysics, and diurnal variations on the vertical structure of tropical tropospheric temperature are investigated by analyzing 10 two-dimensional equilibrium cloud-resolving model simulation data. The increase of SST, exclusion of diurnal variation of SST, and inclusion of diurnal variation of solar zenith angle, radiative effects of ice clouds, and ice microphysics could lead to tropical tropospheric warming and increase of tropopause height. The increase of SST and the suppression of its diurnal variation enhance the warming in the lower and upper troposphere, respectively, through increasing latent heat and decreasing IR cooling. The inclusion of diurnal variation of solar zenith angle increases the tropospheric warming through increasing solar heating. The inclusion of cloud radiative effects increases tropospheric warming through suppressing IR cooling in the mid and lower troposphere and enhancing solar heating in the upper troposphere. The inclusion of ice microphysics barely increases warming in the mid and lower troposphere because the warming from ice radiative effects is nearly offset by the cooling from ice microphysical effects, whereas it causes the large warming enhancement in the upper troposphere due to the dominance of ice radiative effects. The tropopause height is increased mainly through the large enhancement of IR cooling. 相似文献
3.
The understanding of the cloud processes of snowfall is essential to the artificial enhancement of snow and the numerical simulation of snowfall. The mesoscale model MM5 is used to simulate a moderate snowfall event in North China that occurred during 20–21 December 2002. Thirteen experiments are performed to test the sensitivity of the simulation to the cloud physics with different cumulus parameterization schemes and different options for the Goddard cloud microphysics parameterization schemes. It is shown that the cumulus parameterization scheme has little to do with the simulation result. The results also show that there are only four classes of water substances, namely the cloud water, cloud ice, snow, and vapor, in the simulation of the moderate snowfall event. The analysis of the cloud microphysics budgets in the explicit experiment shows that the condensation of supersaturated vapor, the depositional growth of cloud ice, the initiation of cloud ice, the accretion of cloud ice by snow, the accretion of cloud water by snow, the deposition growth of snow, and the Bergeron process of cloud ice are the dominant cloud microphysical processes in the simulation. The accretion of cloud water by snow and the deposition growth of the snow are equally important in the development of the snow. 相似文献
4.
W. S. Lin C.-H. Sui C. Bueh A. Wang S. Fan C. Wu S. Fong J. Li J. Meng 《Meteorology and Atmospheric Physics》2007,95(3-4):195-204
Summary A moderate snowfall event in North China is simulated using the high-resolution mesoscale model MM5. A fourfold-nest experiment,
with a minimum horizontal grid size of 2 km, is run. In order to study the cloud microphysics processes associated with the
snowfall, two experiments were conducted in two inner domains, one using the Goddard scheme (Goddard experiment), and the
other using the Reisner scheme (Reisner experiment). The analysis focused on the comparison of the cloud microphysics processes
which occurred in the experiments.
It is shown that there is no implicit precipitation of cumulus parameterization in the domain of grid scale 18 km. The snowfall
distribution patterns in the experiments are slightly different, but the microphysical characteristics and processes may have
considerable differences between the two experiments: (1) The water substances in the cloud have cloud water, cloud ice and
snow, but no rainwater and graupel in the Goddard experiment. However, the water substances in the cloud have cloud ice, snow,
and graupel, but no cloud water and rainwater in the Reisner experiment. (2) The cloud ice mixing ratios in the Goddard experiment
are larger than those in the Reisner experiment. (3) In the Goddard experiment, the dominant cloud microphysical processes
include the growth of cloud water by the condensation of supersaturated vapor, the depositional growth of cloud ice, the initiation
of cloud ice, the accretion of cloud ice by snow, the accretion of cloud water by snow, the deposition growth of snow and
the Bergeron process of cloud ice. In the Reisner experiment, the dominant cloud microphysical processes include the depositional
growth of cloud ice, the conversion of cloud ice to snow, the deposition of snow, and the deposition growth of graupel. (4)
There is only snowfall in the Goddard experiment. Meanwhile, there is ice fall, snow fall, and graupel in the Reisner experiment.
But the ice fall and graupel in the Reisner experiment is very slight and can be ignored. 相似文献
5.
双参数微物理方案的冰相过程模拟及冰核数浓度的影响试验 总被引：5，自引：2，他引：3
利用耦合Morrison 2-mon(MOR)双参数微物理方案的中尺度天气研究与预报模式(WRF)中的单气柱模式,对热带暖池国际云试验(TWP-ICE)期间的个例进行数值模拟。通过与观测资料和云分辨率模式的模拟结果进行对比,检验MOR方案对热带对流云系的微物理特征的模拟能力。模拟结果显示:MOR方案能够较好地模拟出热带云系中液相和冰相水凝物的垂直分布以及随时间的演变特征。地表向下长波辐射和大气顶向外长波辐射的量级和时间演变趋势同观测也非常接近。对与冰晶和雪有关的云微物理特征分析之后发现:季风活跃期,冰晶主要的源汇项有凝华增长过程、沉降过程、冰晶向雪的自动转化以及冰晶被雪碰并的过程。由于冰晶主体位于温度低于―20℃的高空,因而它对雨水的形成主要是间接贡献。同时期雪的主要源汇项中,凝华增长和沉降过程占据着主导地位。雪的凝华过程消耗了大量的水汽,可能抑制了冰晶的增长。另外雪的融化过程非常强盛,是产生降水的重要因子。季风抑制期,冰相的微物理过程变得相对简单且整体削弱,以凝华升华和沉降过程为主。凝华凝冻核的数浓度(Ndep)的气溶胶敏感性试验表明:季风抑制期,高空的冰晶云的宏观和微观性质对凝华凝冻核数浓度的响应情况呈现显著的线性特征。冰晶的含量随着Ndep的增加而增加,反之降低。该时期微物理过程主要同冰晶有关,水分的分配较为简单,Ndep增加时,高空冰云中小冰晶粒子数目增多且云顶升高,使得大气顶部向外长波辐射(OLR)值减小,反之冰云主体中冰晶有效半径增加,高空的冰云更加透明,云顶更低,对 OLR值增加起促进作用。而季风活跃期,微物理过程复杂,冰晶云的宏微观特征对Ndep的响应表现出一定的不规律特征。 相似文献
6.
应用MM5中尺度模式,选用4种不同云微物理方案(Dudhia简单冰相方案、Reisner混合相方案、Reisner2霰方案和Schultz微物理方案),对2002年7月12-13日祁连山区降水过程进行了数值模拟试验。模拟结果的对比分析表明,不同云微物理方案在祁连山区降水的模拟中对降水落区的模拟均偏南;除Reisner2霰方案外,其他3种方案对降水中心落点的模拟影响不大,降水中心强度对云微物理方案不敏感;显式降水和参数化降水对云微物理方案有不同程度的依赖性;云微物理过程通过影响动力条件发生发展的时间和强度,来影响强降水发生的时间和强度。通过各云微物理参数的分析发现,各物理过程中微物理参数参与降水的过程不同:对Dudhia简单冰相方案来说,雨水和云水是形成降水的主要过程;Reisner混合相方案中降水的形成主要是由于雨水、云水、雪和霰的碰并过程,冰晶的碰并相对较弱;在Reisner2霰方案中,雨水、云水、冰晶、雪和霰均参与碰并碰冻过程;Schultz微物理方案中冰晶、雪和霰的碰并过程更为重要。 相似文献
7.
利用NCEP FNL再分析资料为初始场,通过WRF中尺度数值模式(V3.9.1版本)对2015年8月26~27日青藏高原那曲地区一次对流云降水过程进行了模拟,分析了不同积云对流参数化方案和云微物理参数化方案组合对本次降水过程中降水量、环流场、雷达反射率以及云微物理特征模拟效果的影响。结果表明:WRF模式能较好地模拟出本次降水的时空变化特征,但不同参数化方案组合各有优势,总体而言,Grell-Devenyi+SUBYLIN和Grell-Freitas+SUBYLIN组合模拟性能最优。本次对流云降水以冰相过程为主,雪粒子贡献最大,暖云粒子对降水的影响并不明显。从云微物理过程的时间演变可看出,性能最好的SUBYLIN方案能合理模拟降水过程中雪粒子与冰晶粒子间的转换过程,雪粒子可在凝结过程中释放潜热促使对流运动发展,也可通过融化过程促进降水发生,对流层高层冰晶粒子凝华产生的潜热释放亦为深对流的发展创造了有利条件。 相似文献
8.
使用二维云分辨模式研究冰晶增长过程(云水到冰晶的冻结增长和通过水汽凝华冰晶到雪的增长)对热量收支的影响。采用4种冰晶增长参数化方案模拟了热带到中纬度地区的4个降水个例。研究发现:(1)高冰核浓度的ZENG方案和SHEN方案引起对流层中上层辐射加热增多,这与它们模拟的冰晶在对流层中上层增多有关。(2)高冰核浓度的ZENG方案导致模拟区域—平均的局地温度变化在对流层上层出现异常减小值,这与它在热带个例中导致垂直热量通量辐合减少和在中纬度个例中导致潜热加热减少有关。(3)尽管高冰核浓度的ZENG方案引起质量加权平均的辐射加热增多,但是它在热带个例中引起地表感热通量减少和在中纬度个例中引起潜热加热减少,最终导致4种参数化方案计算的模拟区域—质量加权平均的局地温度变化基本一致。 相似文献
9.
梅雨锋暴雨中的云微物理过程对降水的演变有着重要影响。本文通过WRF模式（3.4.1版本）,针对2018年6月29～30日一次梅雨锋背景下的暴雨过程进行数值模拟,分别采用了Morrison、Thompson和MY云微物理参数化方案进行对比分析,结果发现:（1）三个方案模拟的背景场在天气尺度上,都与ERA5再分析资料一致,能够模拟出有利于强降水发生的环流场。云微物理过程对梅雨期暴雨的局地环流有着显著影响,不同方案存在明显差异,本次过程中,Thompson方案模拟出更强的局地环流系统变率和上升气流。三个方案的模拟降水均有所夸大,小时降水率始终大于观测值。冰相粒子融化或雨滴搜集云滴的高估可能是造成降水模拟值偏强的重要原因之一,总体来看,Morrison方案的模拟效果相对最优。（2）冰相粒子融化、雨滴搜集云滴是雨滴增长的关键源项,蒸发则是其最重要的汇项。总的来说,雨滴对云滴的搜集量大于冰相粒子融化。但上述过程在不同方案中存在空间上的差异,从而使得模拟降水的空间分布存在差异。（3）Thompson方案中,冰相粒子融化量最大,雨滴蒸发项显著大于其它两个方案,在底层表现得最为明显。同时,该方案水汽凝结效应最强,使得雨滴搜集更多云滴。该方案模拟的雨滴最多,降水最强。该方案中凝华的主要产物为雪,且其在与过冷水碰并增长过程中占主导地位,故模拟的雪最多。（4）Morrison方案中,水汽主要凝华为雪和少量霰（冰晶忽略不计）;Thompson方案中水汽基本凝华为雪,其它冰相粒子极少;MY方案中,水汽主要凝华为雪和冰晶,冰晶总量略少于雪,但显著大于其它方案。（5）云滴在凇附过程中的总体贡献大于雨滴。Morrison和MY方案中,霰粒子搜集云滴增长的量均最大。Morrison方案中,其它凇附过程不同程度发挥作用,而MY方案中,其它凇附过程几乎可忽略不计。并且,霰粒子搜集云滴的增长量大于凝华过程产生的雪粒子总量。贝吉龙及凇附效应的差异,是不同方案中冰相粒子分布差异的关键原因之一。 相似文献
10.
Depositional growth of ice crystal is one of the major processes for development of precipitation systems and can be represented by depositional growth of cloud ice from cloud water (PIDW) and depositional growth of snow from cloud ice (PSFI) in cloud-resolving model. Four parameterization schemes are analyzed in the cloud-resolving model simulations of four rainfall cases over the tropics and midlatitudes. The comparison of time and model domain mean data shows that Shen’s scheme produces the closest rainfall simulation to the observation. Compared to Zeng’s scheme, Shen’s scheme improves the mean rain-rate simulation significantly through the dramatic decrease in depositional growth of cloud ice from cloud water. Compared to other schemes, Shen’s scheme produces the better rainfall simulation via the reduction in the mean rain rate associated with the enhanced gain of cloud water and ice. 相似文献
11.
In this study,the effects of key ice microphysical processes on the pre-summer heavy rainfall over southern China during 3-8 June 2008 were investigated.A series of two-dimensional sensitivity cloud-resolving model simulations were forced with zonally uniform vertical velocity,zonal wind,horizontal temperature,and water vapor advection data from the National Centers for Environmental Prediction(NCEP)/Global Data Assimilation System(GDAS).The effects of key ice microphysical processes on the responses of rainfall to large-scale forcing were analyzed by comparing two sensitivity experiments with a control experiment.In one sensitivity experiment,ice crystal radius,associated with depositional growth of snow from cloud ice,was reduced from 100 μm in the control experiment to 50 μm,and in the other sensitivity experiment the efficiency of the growth of graupel from the accretion of snow was reduced to 50% from 100% in the control experiment.The results show that the domain-mean rainfall responses to these ice microphysical processes are stronger during the decay phase than during the onset and mature phases.During the decay phase,the increased mean rain rate resulting from the decrease in ice crystal radius is associated with the enhanced mean local atmospheric drying,the increased mean local hydrometeor loss,and the suppressed mean water vapor divergence.The increased mean rain rate caused by the reduction in accretion efficiency is related to the reduced mean water vapor divergence and the enhanced mean local hydrometeor loss. 相似文献
12.
不同微物理方案对台风“彩虹”(2015)降水影响的比较研究 总被引：1，自引：1，他引：0
本文以GFS资料为初始场,利用WRF（v3.6.1）模式对2015年第22号台风“彩虹”进行了数值研究。采用CMA（中国气象局）台风最佳路径、MTSAT卫星、自动站降水为观测资料,对比了4个微物理方案（Lin、WSM6、GCE和Morrison）对“彩虹”台风路径、强度、结构、降水的模拟性能。模拟发现上述4个云微物理方案都能较好地模拟出“彩虹”台风西行登陆过程,但是其模拟的台风强度、结构及降水存在较大差异;就水成物而言,除GCE方案对雨水的模拟偏高以外,其他方案对云水、雨水过程的模拟较为接近,其差异主要存在于云冰、雪、霰粒子的模拟上。本文对比分析了WSM6和Morrison两个方案模拟的云微物理过程,发现WSM6方案模拟的雪和霰粒子融化过程显著强于Morrison方案,但是冰相粒子间转化过程的强度明显弱于Morrison方案。云微物理过程的热量收支分析表明:WSM6方案模拟的眼区潜热更强,暖心结构更为显著,台风中心气压更低。细致的云微物理转化分析表明,此次台风降水的主要云微物理过程是水汽凝结成云水和凝华为云冰;生成的云水一方面被雨水收集碰并直接转化为雨水,另一方面先被雪粒子碰并收集转化为霰,然后霰粒子融化成雨水;而生成的云冰则通过碰并增长转化为雪。小部分雪粒子通过碰并收集过冷水滴并淞附增长为霰粒子,随后融化为雨水,大部分雪粒子则直接融化形成地面降水。 相似文献
13.
东北冷涡中尺度云系降水机制研究 II: 数值模拟 总被引：1，自引：1，他引：0
在利用卫星、雷达和机载PMS(粒子测量系统)等观测资料对2003年7月8日东北冷涡积层混合云系的降水形成机制分析的基础上,将观测分析与数值模拟研究相结合,用中尺度数值模式对积层混合云系做数值模拟,并结合观测资料进一步分析了积层混合云系的微物理结构、粒子形成过程和降水形成机制,获得如下结果:(1)混合云中对流云具有分层的微物理结构.冰晶含水量最大值出现的高度最高,其次由高到低的排序是雪、云水、霰和雨;雨水主要出现在云的暖区;各种粒子中以雨水含水量最高,其次是霰.对流云体生命期较长,微物理结构基本稳定.(2)粒子形成增长过程有差异.冰晶通过凝华过程增长.雪主要来源于冰晶,产生后主要通过撞冻、收集冰晶和凝华过程增长,其中撞冻过冷云水增长对雪质量贡献最大,其产生率极大值高度与过冷云水相当.丰富的过冷云水,给雪的撞冻增长提供了有利条件.在高、中和低层雪的形成有着不同的机制,高层雪收集冰晶长大后,下落到低层又以雪撞冻过冷云水的结淞增长为主要过程.霰主要由雨滴冻结和雪的转化产生,过冷雨滴与冰晶接触冻结成霰;过冷雨滴收集雪,雪随着雨滴的冻结而转化成霰.因此霰的产生与过冷雨滴关系极大.霰主要撞冻云水、收集雪和冰晶增长,其中撞冻是霰的重要增长过程.雨水主要由霰的融化形成,降水主要是由冷云过程产生的.在过冷层,霰撞冻增长占优势.云上部的冰晶和雪对云的中部具有播撒作用,过冷层中存在丰富的过冷水,对冰相粒子的撞冻增长有利.对云水消耗的分析表明,雨滴对云滴的收集、霰和雪对云水的撞冻增长是消耗云水的主要过程.(3)从各种粒子的形成和增长过程可以看出,大部分雨水由霰融化形成,暖云过程贡献要小得多.可见,降水主要是由冷云过程产生的,这与观测分析的结果一致. 相似文献
14.
THE MICROPHYSICAL STRUCTURE OF SNOW CLOUDS AND THE GROWTH PROCESS OF SNOW PARTICLES IN WINTER IN XINJIANG 
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下载免费PDF全文 The microphysical structure of snow clouds and the growth process of snow crystals were observed by means of instrumented aircraft,weather radar,snow crystal observations etc.in Urumqi region during the winter of 1982.The analysis of three cases show that about 70% of snow mass growth is produced in the lower layer below 2000 m under the cold front,and that the concentration of ice crystals is as high as 60 L-1 and the supercooled water is absent in lower clouds.We may infer that the deposition of ice crystals and the aggregation of snow crystals are important processes for the snow development.The microphysical structure of the snow band near the front aloft and its characteristics as a seeder cloud are also described in this paper. 相似文献
15.
高纬度强对流与对流层上层水汽变化关系的数值模拟研究 总被引：2，自引：2，他引：0
应用WRF中尺度模式模拟了发生在黑龙江省西南部的一次区域性暴雨过程,通过云微物理参数化方案的敏感性试验,分析了对流云体中水汽垂直输送特征.结果表明:强对流活动使对流层上层局地水汽平均增加10倍以上,对流活动对于水汽的垂直输送以及对高层水汽含量的改变具有非常显著的作用.云微物理参数化方案,对于整个对流层水汽通量密度变化趋势有较好的表现.在不同方案中,0.5 ～9 km水汽通量密度及24 h总水汽垂直输送量,随高度变化差异较大.这是由平均垂直速度对不同方案敏感性造成的,不同的参数化方案,水汽通量最大值间最多相差可达27.9％.在不同的方案中,对流层上层加湿作用持续时间和对流层上层平均水汽混合比的最大值较敏感:对流活动可造成模拟区域对流层上层增湿持续16 ～20 h不等;对流层上层平均水汽混合比的最大值差异明显,最大可达15.8％.进行24 h平均后,上述物理量对方案的敏感性可减小到8.3％.所以,云微物理方案的不确定性对于暴雨过程的时间尺度是不可忽视的. 相似文献
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利用GRAPES模式研究气溶胶对云和降水过程的影响 总被引：5，自引：3，他引：2
在GRAPES中尺度模式的双参数微物理方案中加入了气溶胶活化参数化过程,实现了对云滴数浓度的预报。选取不同季节两个降水过程进行模拟,并分别开展了不同气溶胶背景下的两个试验进行对比分析,研究气溶胶对云和降水可能的影响。结果表明:气溶胶浓度增加后,因为活化产生了更多尺度较小的云滴,抑制了云雨的自动转化,使大气中滞留了更多的云水,暖云降水减小;另一方面,云水的增加会使冰相粒子,尤其是雪和霰通过碰并云水等过程而增大,最后融化成雨增加冷云降水,同时冰相粒子增加会释放更多的潜热,促进上升气流的发展,进一步增加冷云降水。气溶胶对降水的影响存在空间不一致性,暖云较厚的地方暖雨过程受到的抑制明显,使地面降水减小,冷云厚度相对较厚时,冷云降水的增加会大于暖云降水的抑制,使地面降水增加。同时由于在云降水发展的不同阶段冷暖云的变化,气溶胶对降水的影响也存在着时间不一致性。 相似文献
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本文以ERA5（ECMWF Reanalysis v5）再分析资料为初始场,利用WRF（The Weather Research and Forecasting）模式对2020年4月19～20日的一次大范围暴雪天气过程进行数值模拟研究。模式采用不同云微物理参数化方案进行敏感性试验,并与实测数据（自动站降水数据、雷达基数据）进行对比,分析了此次暴雪天气过程不同阶段的降水、雷达反射率、动热力和水凝物的时空演变和三维细致结构特征。研究表明:Morrison方案更好的模拟出了本次暴雪天气过程,表现在模拟的雷达回波强度、范围及形态更与实况一致,模拟出的降水量的相关系数和均方根误差都优于其他方案;其微物理细致结构表现为强上升运动和低层正涡度的长时间维持,以及7 km以上高层较多的冰晶、中低层较少的霰粒子和雨水粒子。从热动力场上看,bin（SBM fast）方案在600 hPa高度以下存在明显的涡度波列,这主要是因为bin方案将粒子群分档处理,没有捆绑不同粒子类型运动,更能细致描述出不同粒子的下沉拖曳作用。从云微物理特征上看,不同方案模拟的雪、霰、云水以及雨水粒子的比质量都较为接近,而对冰晶比质量的模拟不管在量级还是在分布范围上都存在很大的差异,这种差异决定了不同微物理方案模拟的雷达回波和降水量级和相态的差异。 相似文献
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云微物理参数化对华北降雪影响的数值模拟 总被引：7，自引：3，他引：7
对发生在华北地区的一次降雪过程进行了中尺度数值模拟。结果表明,高纬强冷空气南下和低纬倒槽的水汽输送是造成这次长时间降雪过程的主要原因。采用混合方案的中尺度数值模拟表明,这次降雪天气不是对流云造成的,而是稳定性的非对流云降雪。敏感性试验也表明,采用其他积云参数化方案对模拟的降雪量基本没有影响。控制试验模拟的24h降雪量与实际观测比较吻合。模拟结果表明,当采用Dudhia简单冰相方案时,会有过多的云冰、过冷却水及雪;当采用Reisner 1混合相方案时,会有过多的云冰和雪;修改的各个Reisner 2方案对此次降雪的预报改进不大,但各个Reisner 2方案的敏感性试验中云冰混合比、过冷却水混合比和雪混合比稍微有差异。 相似文献
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Wenshi Lin Jinping Meng C.-H. Sui Weiguang Meng Jiangnan Li 《Meteorology and Atmospheric Physics》2009,104(1-2):1-11
We performed a modeling study of the cloud processes in a heavy snowfall event occurring in North China on 20–22 December 2004. The nonhydrostatic Mesoscale Model (MM5) was used to carry out experiments with the Reisner-2 explicit microphysical parameterizations in four nested domains to test the sensitivity of simulated heavy snowfall to different snow intercept parameters. Results show that while the different intercept parameters do not significantly affect the accumulated snowfall amounts at the surface in either total amount or location, some microphysical characteristics of the modeled heavy snowfall event are impacted. The budget of cloud microphysics is analyzed to determine the dominant cloud processes. In the control experiment (CTL) with the snow intercept (N os) specified as a function of temperature, the primary simulated hydrometeor is snow, and its mixing ratio is an order of magnitude larger than that of the other cloud species. Relative to CTL, the experiment with a fixed intercept (CON3E6) produced lower snow mixing ratios, more cloud water and graupel mixing ratios. Among the two experiments, while snowfall is slightly smaller in CON3E6, other processes like the rate of graupel fall, condensation and evaporation of cloud water, deposition and sublimation of graupel are all larger in CON3E6 than in CTL. Among CTL, CON3E6, and two more experiments (CON2E7: with a smaller fixed intercept; and NOSQS: N os a function of snow mass mixing ratio), the budget shows that CON3E6 produces the smallest deposition and sublimation of snow, the largest deposition of cloud ice, and the largest conversion from cloud ice to snow. 相似文献