云滴谱的不确定性对中尺度降水的影响
IMPACT OF CLOUD DROPLETS SPECTRAL UNCERTAINTY ON THE MESOSCALE PRECIPITATION
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摘要: 云滴的谱分布通过改变云滴的有效半径影响辐射传输过程,改变大气的热力、动力状况,进而影响云的发展,因此云滴谱将影响云和辐射的相互作用,从而改变地面降水。利用包含详细云微物理方案的MM5V3中尺度模式对1998年6月8日华南暴雨和2002年7月22日长江暴雨进行了数值模拟,研究了中尺度模式中云滴谱的不确定性对地面降水的影响。模拟结果表明,云滴谱在中尺度地面降水中起着重要的作用,其不确定性对地面降水的范围影响很小,却能明显地改变降水强度,能显著地改变地面降水中心的降水量和中心位置,还可能改变降水的起止时间;云滴谱的不确定性能够引起最大超过10%的平均降水强度的改变,而且其差异在白天比夜间更明显。Abstract: The effective radius of cloud droplets,changing due to the cloud droplets spectral uncertainty(CDSU),can affect the radiation transfer processes.This effect may modify the atmospheric thermal and dynamical structure,cloud development,and surface precipitation.The impact of CDSU in the cloud-radiation processes on mesoscale precipitation was studied in this paper using two storm cases,a South China storm on June 8th,1998 and a Yangtze River storm on July 22nd,2002,and employing the MM5V3 with which a newly developed,dual-parameterized explicit moisture scheme is coupled.The results show that CDS plays a very important role in the mesoscale precipitation.Its uncertainty has a slight effect on the overall rainfall pattern,but a significant effect on rainfall intensity.The position and intensity,even the beginning and ending time of the precipitation centers,can also be modified significantly.The maximum change of mean rainfall intensity is over 10% due to CDSU and difference among experiments is more obvious in the daytime than at night.
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Key words:
- cloud radiation /
- mesoscale precipitation /
- effective radius /
- numerical simulation
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[1] FU Q,KRUEGER S K,LIOU K N.Interactions of radiation and convection in simulated tropical cloud clusters[J].J AtmosSci,1995,52(9):1310-1328. [2] TAO W-K,LANG S,SIMPSON J,et al.Mechanisms of Cloud-radiation interaction in the tropics and midlatitudes[J].J Atmos Sci,1996,53(18):2624-2651. [3] 丁守国.积云过程中云与辐射相互作用研究[D].北京:北京大学地球物理系硕士论文,2001. [4] CESS R D,ZHANG M H,INGRAM W J,et al.Cloud feedback in atmospheric general circulation models:An update[J].J Geophys Res,1996,101:12791-12794. [5] HAN Q,ROSSOW W B,LACIS A A.Near-global survey of effective droplet radii in liquid water clouds using ISCCP data[J].J climate,1994,7(4):465-497. [6] LIU Y,DAUM P H.Anthropogenic aerosols indirect warming effect from dispersion forcing[J].Nature,2002,49:580-581. [7] HOUGHTON J T,DING Y,GRIGGS D J,et al.Climate change 2001:The Scientific Basis[A].Contribution of workinggroup I to the third assessment report of the Intergovernmental Panel on Climate Change (IPCC)[C].UK:CambridgeUniversity Press,2001.92. [8] 胡志晋,何观芳.积雨云微物理过程的数值模拟(一)微物理模式[J].气象学报,1987,45(4):467-484. [9] LOU Xiaofeng,HU Zhijin,SHI Yueqin,et al.Numerical simulation of a heavy rainfall case in South China[J].Adv AtmosSci,2003,20:128-138. [10] 许焕斌,王思薇.三维可压缩大气中的云尺度模式[J].气象学报,1990,48(1):80-90. [11] 孔凡铀,黄美元,徐华英.对流云冰相过程的三维数值模拟(Ⅰ)模式建立及冷云参数化[J].大气科学,1990,14(4):441-453. [12] 钱云,钱永甫.区域气候模式中云量参数化方案的研究[J].热带气象学报,1994,10(4):342-348. [13] 石广玉.大气辐射计算的吸收系数分布模式[J].大气科学,1998,22(4):659-673. [14] Wang Hongqi,Zhao Gaoxiang.Parameterization of longwave optical properties for water cloud[J].Adv Atmos Sci,2002,19(1):25-34. [15] 郑庆林,胡一红,古瑜.云、辐射对中期数值预报影响的数值试验[J].应用气象学报,1994,5(4):409-417. [16] 吴涧,罗燕,王卫国.矿尘气溶胶短波辐射效应的初步研究[J].热带气象学报,2004,20(3):328-336. [17] 黎伟标,罗会邦.地气系统净辐射加热的季节变化及其与亚洲夏季风的关系[J].热带气象学报,1999,15(3):205-212. [18] 付遵涛,刘式适.辐射冷却与低频振荡中的宽频带现象[J].热带气象学报,1999,15(4):330-339. [19] 蒋国荣,沙文钰,阎俊岳,等.南海季风爆发前后辐射特征分析[J].热带气象学报,2002,18(1):29-37. [20] 赵春生,丁守国,秦瑜.云内辐射传输过程对对流降水过程的影响[J].自然科学进展,2003,13(10):1060-1066. [21] 楼小凤.MM5模式的新显式云物理方案的建立和耦合及原微物理方案的对比分析[D].北京:北京大学物理学院大气科学系博士论文,2002. [22] LIOU K N,FU Q.A simple formulation of the delta-four-stream approximation for radiative transfer parameterization[J].J Atmos Sci,1988,45(13):1940-1947. [23] FU Q,LIOU K N.On the correlated k-distribution method for radiative transfer in nonhomogeneous atmospheres[J].J AtmosSci,1992,49(22):2139-2156. [24] FU Q,LIOU K N.Parameterization for the radiative properties of cirrus cloud[J].J Atmos Sci,1993,50(13):2008-2025.
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