藏东南草地下垫面地气通量交换日变化的数值模拟
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摘要
利用2013年5月21日至7月9日藏东南地区草地下垫面的边界层观测数据,分别从典型晴天和长时间平均的角度,评估了中尺度模式WRF对藏东南草地下垫面在南亚季风爆发前后的感热、潜热、地表土壤热通量和地表辐射平衡各分量日变化的模拟能力,对比分析了模拟结果与边界层观测数据的异同点。对典型晴天少云状况的个例模拟和整个时段的平均结果分析均表明,模式对感热通量和潜热通量的日变化具有较好的模拟能力,感热比潜热的模拟效果好,在夜间感热和潜热的模拟效果好,而白天感热和潜热的模拟值大于观测值。典型晴天天气下的向下短波辐射和净辐射的模拟值与观测值基本一致,而向上短波辐射的模拟值在白天大于观测值。长时间平均的向下短波辐射、向上短波辐射和净辐射的模拟值在夜间也与观测数据基本一致,但在白天模拟值比观测值明显偏大。晴天个例和长时间模拟的向下长波辐射和向上长波辐射的模拟值在日循环整个过程中较观测值均偏小。长时间模拟的地表土壤热通量在早上和晚上低于观测值,而在白天高于观测值。虽然平均的结果分析和晴天个例的结果是类似的,但由于晴天个例没有降水过程的干扰,因此晴天天气状态下的分析结果更能一致地反映出这一地区的日变化特征。
Based on the boundary layer observations of the grassland in Southeast Tibet for the period from 21 May to 9 July 2013,the WRF simulation capacity on the diurnal variations of sensible heat flux,latent heat flux,surface soil heat flux and each component of radiation balance over the grassland in Southeast Tibet before and after the South Asia summer monsoon burst was evaluated from perspective view of a typical sunny day and longtime average,respectively. This study is trying to find out the differences and similarities between simulation results and boundary layer observations. The results of the case simulation over a typical sunny day and the longtime simulation during the whole observation period all show that the model has a good performance in modeling the diurnal variations of sensible heat flux and latent heat flux,the simulating effect of sensible heat flux is better than that of latent heat flux. The simulating effects of sensible heat flux and latent heat flux are good at nighttime,and in the daytime,the simulated values of sensible heat flux and latent heat flux are larger than the observed values. The simulated values of downward shortwave radiation and net radiation over the typical sunny weather day are all basically consistent with the observed values,but the simulated values of upward shortwave radiation are larger than the observed values at day-time. The long-time simulation results of downward shortwave radiation,upward shortwave radiation and net radiation basically agree well with the observed data at night-time,but in the daytime,the simulated values are significantly larger than the observed values. Both the typical sunny day simulated values and the long-time simulated values of long wave radiation from the atmosphere and long wave radiation from the earth are smaller than the observed values during the whole day. The long-time simulated values of surface soil heat flux are lower than the observed values in the morning and evening,but in the daytime,the simulated values are higher than the observed values. While the long-time average results and the sunny day results are similar,but without the disturbance of precipitation process,the analysis results on sunny weather conditions can more consistently reflect the diurnal variation characteristics of this region.
Based on the boundary layer observations of the grassland in Southeast Tibet for the period from 21 May to 9 July 2013,the WRF simulation capacity on the diurnal variations of sensible heat flux,latent heat flux,surface soil heat flux and each component of radiation balance over the grassland in Southeast Tibet before and after the South Asia summer monsoon burst was evaluated from perspective view of a typical sunny day and longtime average,respectively. This study is trying to find out the differences and similarities between simulation results and boundary layer observations. The results of the case simulation over a typical sunny day and the longtime simulation during the whole observation period all show that the model has a good performance in modeling the diurnal variations of sensible heat flux and latent heat flux,the simulating effect of sensible heat flux is better than that of latent heat flux. The simulating effects of sensible heat flux and latent heat flux are good at nighttime,and in the daytime,the simulated values of sensible heat flux and latent heat flux are larger than the observed values. The simulated values of downward shortwave radiation and net radiation over the typical sunny weather day are all basically consistent with the observed values,but the simulated values of upward shortwave radiation are larger than the observed values at day-time. The long-time simulation results of downward shortwave radiation,upward shortwave radiation and net radiation basically agree well with the observed data at night-time,but in the daytime,the simulated values are significantly larger than the observed values. Both the typical sunny day simulated values and the long-time simulated values of long wave radiation from the atmosphere and long wave radiation from the earth are smaller than the observed values during the whole day. The long-time simulated values of surface soil heat flux are lower than the observed values in the morning and evening,but in the daytime,the simulated values are higher than the observed values. While the long-time average results and the sunny day results are similar,but without the disturbance of precipitation process,the analysis results on sunny weather conditions can more consistently reflect the diurnal variation characteristics of this region.
引文
Beljaars A C M,Holtslag A A M,1991.Flux parameterization over land surfaces for atmospheric models[J].J Appl Meteor,30:327-341.
Businger J A,Wyngaard J C,Izumi Y,et al,1971.Flux-profile relationships in the atmospheric surface layer[J].J Atmos Sci,28(2):181-189.
Cheng W Y Y,Steenburgh W J,2005.Evaluation of surface sensible weather forecasts by the WRF and the Eta models over the western United States[J].Wea Forecasting,20(5):812-821.
Dyer A J,1974.A review of flux-profile relationships[J].Bound Layer Meteor,7(3):363-372.
Holtslag A A M,De Bruin H A R,1988.Applied modeling of the nighttime surface energy balance over land[J].J Appl Meteor,27(6):689-704.
Hong S Y,Noh Y,Dudhia J,2006.A new vertical diffusion package with an explicit treatment of entrainment processes[J].Mon Wea Rev,134(9):2318-2341.DOI:10.117/MWR3199.1.
Kuo H L,Qian Y F,1981.Influence of the Tibetan Plateau on cumulative and diurnal changes of weather and climate in summer[J].Mon Wea Rev,109:2337-2356.
Zhou L,Zou H,Ma S,et al,2015.The observed impacts of South Asian summer monsoon on the local atmosphere and the near surface turbulent heat exchange over the Southeast Tibet[J].J Geophys Res Atmos,120(22):11509-11518.DOI:10.1002/2014JD022928.
季国良,时兴和,高务祥,2001.藏北高原地面加热场的变化及其对气候的影响[J].高原气象,20(3):239-244.Ji G L,Shi X H,Gao W X,2001.The variation of surface heating field over northern Qinghai-Tibet Plateau and its effect on climate[J].Plateau Meteor,20(3):239-244.
季国良,顾本文,吕兰芝,2002.青藏高原北部的大气加热场特征[J].高原气象,21(3):238-242.Ji G L,Gu B W,LüL Z,2002.Characteristics of atmospheric heating field over northern Qinghai-Xizang Plateau[J].Plateau Meteor,21(3):238-242.
李娟,李跃清,蒋兴文,等,2016.青藏高原东南部复杂地形区不同天气状况下陆气能量交换特征分析[J].大气科学,40(4):777-791.Li J,Li Y Q,Jiang X W,et al,2016.Characteristics of land-atmosphere energy exchanges over complex terrain area of southeastern Tibetan Plateau under different synoptic conditions[J].Chinese J Atmos Sci,40(4):777-791.
李斐,邹捍,周立波,等,2017.WRF模式中边界层参数化方案在藏东南复杂下垫面适用性研究[J].高原气象,36(2):340-357.Li F,Zou H,Zhou L B,et al,2017.Study of boundary layer parameterization schemes’applicability of WRF model over complex underlying surfaces in Southeast Tibet[J].Plateau Meteor,36(2):340-357.DOI:10.7522/j.issn.1000-0534.2016.00041.
缪国军,张镭,舒红,2007.利用WRF对兰州冬季大气边界层的数值模拟[J].气象科学,27(2):169-175.Miao G J,Zhang L,Shu H,2007.The numerical simulation of the wind speed and temperature field in winter atmospheric boundary layer in Lanzhou by using WRF[J].Sci Meteor Sinica,27(2):169-175.
钱永甫,1993.气候变化中下垫面作用的数值模拟[J].大气科学,17(3):283-293.Qian Y F,1993.Numerical simulation of the effects of underlying surfaces on the climate change[J].Chinese JAtmos Sci,17(3):283-293.
石春娥,李耀孙,杨军,等,2015.MM5和WRF对中国东部地区冬季边界层模拟效果比较[J].高原气象,34(2):389-400.Shi CE,Li Y S,Yang J,et al,2015.Comparison of simulations on winter sounding profiles in PBL in East China between WRF and MM5[J].Plateau Meteor,34(2):389-400.DOI:10.7552/j.issn.1000-0534.2013.00206.
王澄海,董文杰,韦志刚,2003.青藏高原季节冻融过程与东亚大气环流关系的研究[J].地球物理学报,46(3):309-316.Wang CH,Dong W J,Wei Z G,2003.Study on relationship between the frozen-thaw process in Qinghai-Xizang Plateau and circulation in East-Asia[J].Chinese J Geophys,46(3):309-316.
王寅钧,周明煜,徐祥德,等,2013.MM5和ETA相似理论近地层方案对农田下垫面通量模拟比较研究[J].气象学报,71(4):677-691.Wang Y J,Zhou M Y,Xu X D,et al,2013.Comparative study of the similarity surface layer schemes simulate turbulent flux simulations over cropland between MM5 and ETA[J].Acta Meteor Sinica,71(4):677-691.
王寅钧,2011.青藏高原东南部WRF边界层模拟与观测对比探讨研究[D].南京:南京信息工程大学,63.Wang Y J,2011.The contrast research between boundary layer simulation using the WRFmodel and observation result in the southeast of Qinghai-Tibet plateau[D].Nanjing:Nanjing University of Information Science and Technology,63.
王颖,张镭,胡菊,等,2010.WRF模式对山谷城市边界层模拟能力的检验及地面气象特征分析[J].高原气象,29(6):1397-1407.Wang Y,Zhang L,Hu J,et al,2010.Verification of WRFsimulation capacity on PBL characteristic and Analysis of surface meteorological characteristic over complex Terrain[J].Plateau Meteor,29(6):1397-1407.
王鸽,韩琳,唐信英,等,2014.藏东南地区复杂下垫面能量收支特征分析[J].高原山地气象研究,34(4):44-47.Wang G,Han L,Tang X Y,et al,2014.Analysis on the features of energy budget on the complicated underlying surfaces in southeast Tibet[J].Plateru Mountain Meteor Res,34(4):44-47.
王腾蛟,张镭,胡向军,等,2013.WRF模式对黄土高原丘陵地形条件下夏季边界层结构的数值模拟[J].高原气象,32(5):1261-1271.Wang T J,Zhang L,Hu X J,et al,2013.Numerical simulation of summer boundary layer structure over undulating topography of Loess Plateau simulated by WRF model[J].Plateau Meteor,32(5):1261-1271.DOI:10.7522/j.issn.1000-0534.2012.00121.
文小航,吕世华,孟宪红,等,2010.WRF模式对金塔绿洲效应的数值模拟[J].高原气象,29(5):1163-1173.Wen X H,LüS H,Meng X H,et al,2010.Numerical simulation of oasis effect in Jinta oasis using the WRF model[J].Plateau Meteor,29(5)1163-1173.
徐祥德,陶诗言,王继志,等,2002.青藏高原-季风水汽输送“大三角扇形”影响域特征与中国区域旱涝异常的关系[J].气象学报,60(3):257-266.Xu X D,Tao S Y,Wang J Z,et al,2002.The relationship between water vapor transport features of Tibetan Plateaumonsoon“Large Triangle”affecting region and drought-flood abnormality of China[J].Acta Meteor Sinica,60(3):257-266.
吴国雄,孙淑芬,陈文,等,2003.青藏高原与西北干旱区对气候灾害的影响[M].北京:气象出版社,207.Wu G X,Sun S F,Chen W,et al,2003.The impact of Qinghai-Tibet Plateau and northwest arid areas on climate disasters[M].Beijing:China Meteorological Press,207.
叶笃正,张捷迁,1974.青藏高原加热作用对夏季东亚大气环流影响的初步模拟实验[J].中国科学,17(3):301-320.Ye D Z,Zhang J Q,1974.A preliminary experimental simulation on the heating effect of the Tibetan Plateau on the general circulation over Eastern Asia in summer[J].Sci Sinica,17(3):397-420.
叶笃正,高由禧,1979.青藏高原气象学[M].北京:科学出版社,278.Ye D Z,Gao Y X,1979.Tibetan Plateau Meteorology[M].Beijing:Science Press,278.
章基嘉,朱抱真,朱福康,等,1988.青藏高原气象学进展[M].北京:科学出版社,268.Zhang J J,Zhu B Z,Zhu F K,et al,1988.The progress introduction on the study of Tibetan Plateau meteorology[M].Beijing:Science Press,268.
周强,李国平,2013.边界层参数化方案对高原低涡东移模拟的影响[J].高原气象,32(2):334-344.Zhou Q,Li G P,2013.Impact of the different boundary layer parameterization schemes on numerical simulation of Plateau vortex moving eastward[J].Plateau Meteor,32(2):334-344.DOI:10.7522/j.issn.1000-0534.2012.00033.
Businger J A,Wyngaard J C,Izumi Y,et al,1971.Flux-profile relationships in the atmospheric surface layer[J].J Atmos Sci,28(2):181-189.
Cheng W Y Y,Steenburgh W J,2005.Evaluation of surface sensible weather forecasts by the WRF and the Eta models over the western United States[J].Wea Forecasting,20(5):812-821.
Dyer A J,1974.A review of flux-profile relationships[J].Bound Layer Meteor,7(3):363-372.
Holtslag A A M,De Bruin H A R,1988.Applied modeling of the nighttime surface energy balance over land[J].J Appl Meteor,27(6):689-704.
Hong S Y,Noh Y,Dudhia J,2006.A new vertical diffusion package with an explicit treatment of entrainment processes[J].Mon Wea Rev,134(9):2318-2341.DOI:10.117/MWR3199.1.
Kuo H L,Qian Y F,1981.Influence of the Tibetan Plateau on cumulative and diurnal changes of weather and climate in summer[J].Mon Wea Rev,109:2337-2356.
Zhou L,Zou H,Ma S,et al,2015.The observed impacts of South Asian summer monsoon on the local atmosphere and the near surface turbulent heat exchange over the Southeast Tibet[J].J Geophys Res Atmos,120(22):11509-11518.DOI:10.1002/2014JD022928.
季国良,时兴和,高务祥,2001.藏北高原地面加热场的变化及其对气候的影响[J].高原气象,20(3):239-244.Ji G L,Shi X H,Gao W X,2001.The variation of surface heating field over northern Qinghai-Tibet Plateau and its effect on climate[J].Plateau Meteor,20(3):239-244.
季国良,顾本文,吕兰芝,2002.青藏高原北部的大气加热场特征[J].高原气象,21(3):238-242.Ji G L,Gu B W,LüL Z,2002.Characteristics of atmospheric heating field over northern Qinghai-Xizang Plateau[J].Plateau Meteor,21(3):238-242.
李娟,李跃清,蒋兴文,等,2016.青藏高原东南部复杂地形区不同天气状况下陆气能量交换特征分析[J].大气科学,40(4):777-791.Li J,Li Y Q,Jiang X W,et al,2016.Characteristics of land-atmosphere energy exchanges over complex terrain area of southeastern Tibetan Plateau under different synoptic conditions[J].Chinese J Atmos Sci,40(4):777-791.
李斐,邹捍,周立波,等,2017.WRF模式中边界层参数化方案在藏东南复杂下垫面适用性研究[J].高原气象,36(2):340-357.Li F,Zou H,Zhou L B,et al,2017.Study of boundary layer parameterization schemes’applicability of WRF model over complex underlying surfaces in Southeast Tibet[J].Plateau Meteor,36(2):340-357.DOI:10.7522/j.issn.1000-0534.2016.00041.
缪国军,张镭,舒红,2007.利用WRF对兰州冬季大气边界层的数值模拟[J].气象科学,27(2):169-175.Miao G J,Zhang L,Shu H,2007.The numerical simulation of the wind speed and temperature field in winter atmospheric boundary layer in Lanzhou by using WRF[J].Sci Meteor Sinica,27(2):169-175.
钱永甫,1993.气候变化中下垫面作用的数值模拟[J].大气科学,17(3):283-293.Qian Y F,1993.Numerical simulation of the effects of underlying surfaces on the climate change[J].Chinese JAtmos Sci,17(3):283-293.
石春娥,李耀孙,杨军,等,2015.MM5和WRF对中国东部地区冬季边界层模拟效果比较[J].高原气象,34(2):389-400.Shi CE,Li Y S,Yang J,et al,2015.Comparison of simulations on winter sounding profiles in PBL in East China between WRF and MM5[J].Plateau Meteor,34(2):389-400.DOI:10.7552/j.issn.1000-0534.2013.00206.
王澄海,董文杰,韦志刚,2003.青藏高原季节冻融过程与东亚大气环流关系的研究[J].地球物理学报,46(3):309-316.Wang CH,Dong W J,Wei Z G,2003.Study on relationship between the frozen-thaw process in Qinghai-Xizang Plateau and circulation in East-Asia[J].Chinese J Geophys,46(3):309-316.
王寅钧,周明煜,徐祥德,等,2013.MM5和ETA相似理论近地层方案对农田下垫面通量模拟比较研究[J].气象学报,71(4):677-691.Wang Y J,Zhou M Y,Xu X D,et al,2013.Comparative study of the similarity surface layer schemes simulate turbulent flux simulations over cropland between MM5 and ETA[J].Acta Meteor Sinica,71(4):677-691.
王寅钧,2011.青藏高原东南部WRF边界层模拟与观测对比探讨研究[D].南京:南京信息工程大学,63.Wang Y J,2011.The contrast research between boundary layer simulation using the WRFmodel and observation result in the southeast of Qinghai-Tibet plateau[D].Nanjing:Nanjing University of Information Science and Technology,63.
王颖,张镭,胡菊,等,2010.WRF模式对山谷城市边界层模拟能力的检验及地面气象特征分析[J].高原气象,29(6):1397-1407.Wang Y,Zhang L,Hu J,et al,2010.Verification of WRFsimulation capacity on PBL characteristic and Analysis of surface meteorological characteristic over complex Terrain[J].Plateau Meteor,29(6):1397-1407.
王鸽,韩琳,唐信英,等,2014.藏东南地区复杂下垫面能量收支特征分析[J].高原山地气象研究,34(4):44-47.Wang G,Han L,Tang X Y,et al,2014.Analysis on the features of energy budget on the complicated underlying surfaces in southeast Tibet[J].Plateru Mountain Meteor Res,34(4):44-47.
王腾蛟,张镭,胡向军,等,2013.WRF模式对黄土高原丘陵地形条件下夏季边界层结构的数值模拟[J].高原气象,32(5):1261-1271.Wang T J,Zhang L,Hu X J,et al,2013.Numerical simulation of summer boundary layer structure over undulating topography of Loess Plateau simulated by WRF model[J].Plateau Meteor,32(5):1261-1271.DOI:10.7522/j.issn.1000-0534.2012.00121.
文小航,吕世华,孟宪红,等,2010.WRF模式对金塔绿洲效应的数值模拟[J].高原气象,29(5):1163-1173.Wen X H,LüS H,Meng X H,et al,2010.Numerical simulation of oasis effect in Jinta oasis using the WRF model[J].Plateau Meteor,29(5)1163-1173.
徐祥德,陶诗言,王继志,等,2002.青藏高原-季风水汽输送“大三角扇形”影响域特征与中国区域旱涝异常的关系[J].气象学报,60(3):257-266.Xu X D,Tao S Y,Wang J Z,et al,2002.The relationship between water vapor transport features of Tibetan Plateaumonsoon“Large Triangle”affecting region and drought-flood abnormality of China[J].Acta Meteor Sinica,60(3):257-266.
吴国雄,孙淑芬,陈文,等,2003.青藏高原与西北干旱区对气候灾害的影响[M].北京:气象出版社,207.Wu G X,Sun S F,Chen W,et al,2003.The impact of Qinghai-Tibet Plateau and northwest arid areas on climate disasters[M].Beijing:China Meteorological Press,207.
叶笃正,张捷迁,1974.青藏高原加热作用对夏季东亚大气环流影响的初步模拟实验[J].中国科学,17(3):301-320.Ye D Z,Zhang J Q,1974.A preliminary experimental simulation on the heating effect of the Tibetan Plateau on the general circulation over Eastern Asia in summer[J].Sci Sinica,17(3):397-420.
叶笃正,高由禧,1979.青藏高原气象学[M].北京:科学出版社,278.Ye D Z,Gao Y X,1979.Tibetan Plateau Meteorology[M].Beijing:Science Press,278.
章基嘉,朱抱真,朱福康,等,1988.青藏高原气象学进展[M].北京:科学出版社,268.Zhang J J,Zhu B Z,Zhu F K,et al,1988.The progress introduction on the study of Tibetan Plateau meteorology[M].Beijing:Science Press,268.
周强,李国平,2013.边界层参数化方案对高原低涡东移模拟的影响[J].高原气象,32(2):334-344.Zhou Q,Li G P,2013.Impact of the different boundary layer parameterization schemes on numerical simulation of Plateau vortex moving eastward[J].Plateau Meteor,32(2):334-344.DOI:10.7522/j.issn.1000-0534.2012.00033.