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1.
《大气和海洋科学快报》2021,(1)
为评估CWRF模式的降尺度能力和其热带气旋模拟对物理参数化方案的敏感性,本文利用ERI再分析资料驱动CWRF在30km网格上对1982-2016年中国近海热带气旋开展了一次集合模拟.结果表明:CWRF与ERI均能模拟出热带气旋的季节变化和年际变化形势且均存在低估,但相较ERI,CWRF的降尺度技术和集合模拟可以再现更多的热带气旋,显著减少低估.年际变化结果提升最为明显,它对积云方案最为敏感,其次是边界层,陆面和辐射方案,对云和微物理方案较弱.该研究为应用CWRF理解和预报热带气旋提供了参考. 相似文献
2.
利用欧洲中期天气预报中心的ERA-Interim再分析资料驱动CWRF模式对1982-2016年中国近海的热带气旋活动进行了模拟,分析了CWRF对热带气旋频数季节、年际变化和路径的模拟能力,并探讨了环境场模拟对热带气旋模拟的影响。结果表明:CWRF能够合理模拟热带气旋频数的季节和年际变化,但模拟的频数较观测总体偏低,季节变化模拟总体优于年际变化的模拟;模式基本上能模拟出热带气旋路径密度的空间分布,但CWRF明显总体低估了气旋路径密度。进一步分析发现,模式模拟的环境场对模拟结果具有十分重要的影响。850 hPa气旋性与反气旋性环流异常对热带气旋频数影响显著;200 hPa反气旋性环流异常与东亚西风急流对热带气旋路径影响较大;副高会影响洋面对流运动从而影响热带气旋频数,其南侧偏东风则会影响热带气旋路径;垂直风切变偏小,在不同纬度对热带气旋的影响是不同的。 相似文献
3.
基于CWRF模式（Climate Extension of Weather Research and Forecast Model）结果,探讨了8种云微物理参数化方案对1986—2015年间东亚近海热带气旋的空间分布、频数及强度模拟的影响。结果发现：CWRF模式中各云微物理参数化方案模拟的热带气旋频数普遍较观测偏少,其模拟的强度相比观测也偏弱;热带气旋的空间分布和频数对云微物理参数化方案的选择较为敏感,而云微物理方案的选择对热带气旋强度的模拟影响不大;Morrison方案和Morrison-a方案模拟的热带气旋空间分布更接近于观测,但对热带气旋频数及强度的年际变化趋势模拟得较差,而GSFCGCE方案的TS评分及强度、频数的相关系数均较其他方案偏高。综合来看,采用GSFCGCE方案模拟热带气旋活动总体最优。进一步分析发现,相较于Morrison方案和Thompson方案,考虑气溶胶影响的Thompson-a和Morrison-a方案不仅可以有效提高对热带气旋频数及空间分布的模拟能力,还对热带气旋频数及强度年际变化趋势的模拟能力也有所提升。 相似文献
4.
基于CWRF高分辨率模式的模拟结果,探讨了8种积云对流参数化方案对1986—2015年间东亚近海热带气旋的路径、频数及强度模拟的影响。结果发现:采用Kain-Fritsch方案模拟的热带气旋活动的空间分布与JTWC统计结果最接近。KF方案模拟的热带气旋生成频数(强度)明显高(强)于其他积云对流参数化方案,而BMJ方案模拟的热带气旋生成频数(强度)明显低(弱)于其他积云对流参数化方案。进一步分析发现,采用优化集合积云参数化方案(ECP)模拟热带气旋频数、ACE指数以及PDI指数的年际变化趋势较好,而采用KF积云对流参数化方案对热带气旋空间分布、频数及强度的模拟总体最优。 相似文献
5.
利用CWRF(Climate-Weather Research and Forecasting model)对中国区域气候的31 a多物理集合模拟试验,分析了该模式对青藏高原气温和降水的模拟效果及其对水平分辨率和物理过程参数化方案的敏感性。结果表明:1)CWRF降尺度全面改善了全球模式对高原气温和降水的模拟,使气温年循环的均方根误差减小近1℃,月降水量年循环的均方根误差减小10~40 mm,同时显著提高了各月气温和降水与实测资料年际变化的相关系数,最高提升0.6;2)模式分辨率对降水模拟有显著影响,不同分辨率模拟降水差异高达60 mm(54%),模拟偏差随分辨率提高先降低后上升,转折在30 km左右;3)物理过程参数化方案对气温和降水模拟影响显著,不同方案模拟的各月平均气温相差1~4℃,夏季各月降水量相差20~100 mm,其中对气温模拟影响最大的是辐射方案,对降水影响最大的是积云方案。本文为CWRF局地优化对物理参数化及水平分辨率等如何选择提供了依据。 相似文献
6.
基于CWRF模式结果,探讨了6种边界层参数化方案对30 a东亚近海热带气旋的强度、频数及路径模拟的可能影响。结果发现：CWRF模式中各边界层参数化方案模拟的热带气旋频数普遍较观测偏少,模拟强度相比观测也均偏弱。热带气旋的强度、频数及出现频次的空间分布对模式边界层方案的选取较为敏感。CAM3方案模拟强热带气旋的能力较其他方案偏好,ACM方案在多数年份模拟的热带气旋个数偏多,且在不同月份模拟的热带气旋生成频率与观测最接近,CAM3方案模拟的热带气旋出现频次与观测的偏差在大部分地区偏小。综合来看,CWRF模式中边界层参数化选用CAM3方案模拟热带气旋活动的性能较好。 相似文献
7.
利用CWRF模式(Climate-Weather Research and Forecasting model)对国家气候中心BCC_CSM1.1m业务预测模式短期气候预测结果进行中国区域降尺度,并使用1991—2010年3—8月逐日气温降水观测数据评估预测能力。结果表明:CWRF预测地面2 m气温、降水气候平均态的空间分布比BCC_CSM1.1m更接近观测,分布误差更小;在保持总体技巧不低于BCC_CSM1.1m的同时,CWRF对我国华东和华中地区的降水年际变化预测准确率更高;对不同强度的降水预测CWRF表现均优于BCC_CSM1.1 m模式,尤其在极端降水预测准确率上更优。总之,得益于更高的空间分辨率和优化的低空物理过程模拟,CWRF降尺度可以提高中国夏季跨季度降水预测能力。 相似文献
8.
基于气候系统模式FGOALS-g2的热带气旋活动及其影响的动力降尺度模拟 总被引：2，自引：2，他引：0
热带气旋是气候模拟关注的重要对象,但是,由于当前的气候系统模式分辨率较低,难以合理再现热带气旋分布特征,因此,动力降尺度就成为一种有效的手段。本文使用区域气候模式RegCM3,对中国科学院大气物理研究所气候系统模式FGOALS-g2的模拟结果进行动力降尺度,基于热带气旋路径追踪法,从热带气旋的路径、强度和降水三个方面,检验了动力降尺度在热带气旋模拟能力上的增值。结果表明,动力降尺度结果大幅提升了热带气旋路径频率的模拟,较之全球模式,其与观测的路径频率分布的空间相关系数从0.57提升至0.74;区域模式模拟的热带气旋强度与观测更为一致,全球模式难以模拟40 m s?1以上风速的热带气旋,区域模式能够模拟风速为60 m s?1的热带气旋;在热带气旋降水方面,降尺度后的热带气旋降水贡献率和平均热带气旋降水强度均有所改善,在西北太平洋区域较之全球模式,区域模式将热带气旋降水贡献率和降水强度提高了10%和4.7 mm d?1。动力降尺度后TC（tropical cyclone）的模拟技巧得到提升的区域为西北太平洋区域,但在中国南海区域,技巧提升的不显著甚至有所下降。关于动力降尺度结果在西北太平洋区域的技巧提升,分析表明能够更好体现CISK（Conditional Instability of the Second Kind）机制是主要原因,区域模式模拟的水汽增多、正涡度增强、上升运动增强而垂直风切变减弱都有显著贡献。 相似文献
9.
基于1980—2015年6—8月CWRF模式（Climate-Weather Research and Forecasting model）14种方案的模拟结果和全国逐日降水观测资料,对比了Q-lin,Q-tri,RQ-lin,RQ-tri,SSP-lin和CDFt 6种误差订正方法对CWRF模式控制化方案（C1）模拟中国东部夏季日极端降水的订正效果,以CWRF模式14种方案日极端降水的模拟效果排名为基础,对比了模拟效果较好的4种方案集合、模拟较差的4种方案集合以及14种方案集合的订正效果,选出相对较好的订正方案进一步评估其成员集合后订正和成员分别订正后再集合的订正效果,结果表明:采用6种误差订正方法均可明显减少日极端降水模拟误差,其中RQ-lin方法订正效果最佳。CWRF模式对中国东部的极端降水指数均表现出较好的模拟能力,不同参数化集合方案得到14种方案成员先订正再集合与观测日极端降水平均值最为接近,研究结果对于改进模拟结果、提高其预测能力有重要应用价值。 相似文献
10.
近52年北上热带气旋的若干气候特征 总被引：5，自引：1，他引：5
应用1951-2002年热带气旋年鉴资料，对52年来北上热带气旋的月际变化、年际和年代际变化、气候突变、振荡周期等若干气候特征进行了分析。结果表明：北上热带气旋的月际变化特征明显，7—9月是北上热带气旋发生的关键月份，尤其7、8月是高峰期，1-4月和12月没有北上热带气旋。北上热带气旋的年际变化表现为略有上升的趋势，并以每10年3％的倾向率上升。用Mann-Kendall方法作突变分析，没有明显的突变年。近52年，北上热带气旋呈现出明显的年际和年代际变化特征，存在5年的显著年际周期，同时还存在10～12年、20-22年的年代际振荡周期。 相似文献
11.
CWRF-based ensemble simulation of tropical cyclone activity near China and its sensitivity to the model physical parameterization schemes: 基于CWRF的中国近海热带气旋集合模拟及其对物理参数化方案的敏感性研究 
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下载免费PDF全文 《大气和海洋科学快报》2021,14(1):100004
To evaluate the downscaling ability with respect to tropical cyclones (TCs) near China and its sensitivity to the model physics representation, the authors performed a multi-physics ensemble simulation with the regional Climate–Weather Research and Forecasting (CWRF) model at a 30 km resolution driven by ERA-Interim reanalysis data. The ensemble consisted of 28 integrations during 1979–2016 with varying CWRF physics configurations. Both CWRF and ERA-Interim can generally capture the seasonal cycle and interannual variation of the TC number near China, but evidently underestimate them. The CWRF downscaling and its multi-physics ensemble can notably reduce the underestimation and significantly improve the simulation of the TC occurrences. The skill enhancement is especially large in terms of the interannual variation, which is most sensitive to the cumulus scheme, followed by the boundary layer, surface and radiation schemes, but weakly sensitive to the cloud and microphysics schemes. Generally, the Noah surface scheme, CAML(CAM radiation scheme as implemented by Liang together with the diagnostic cloud cover scheme of Xu and Randall(1996)) radiation scheme, prognostic cloud scheme, and Thompson microphysics scheme stand out for their better performance in simulating the interannual variation of TC number. However, the Emanuel cumulus and MYNN boundary layer schemes produce severe interannual biases. Our study provides a valuable reference for CWRF application to improve the understanding and prediction of TC activity.摘要为评估CWRF模式的降尺度能力和其热带气旋模拟对物理参数化方案的敏感性, 本文利用ERI再分析资料驱动CWRF在30km网格上对1982-2016年中国近海热带气旋开展了一次集合模拟.结果表明:CWRF与ERI均能模拟出热带气旋的季节变化和年际变化形势且均存在低估, 但相较ERI, CWRF的降尺度技术和集合模拟可以再现更多的热带气旋, 显著减少低估.年际变化结果提升最为明显, 它对积云方案最为敏感, 其次是边界层, 陆面和辐射方案, 对云和微物理方案较弱.该研究为应用CWRF理解和预报热带气旋提供了参考. 相似文献
12.
Evaluating rainfall patterns using physics scheme ensembles from a regional atmospheric model 总被引：2，自引：0，他引：2
Fei Ji Marie Ekström Jason P. Evans Jin Teng 《Theoretical and Applied Climatology》2014,115(1-2):297-304
This study evaluated the ability of Weather Research and Forecasting (WRF) multi-physics ensembles to simulate storm systems known as East Coast Lows (ECLs). ECLs are intense low-pressure systems that develop off the eastern coast of Australia. These systems can cause significant damage to the region. On the other hand, the systems are also beneficial as they generate the majority of high inflow to coastal reservoirs. It is the common interest of both hazard control and water management to correctly capture the ECL features in modeling, in particular, to reproduce the observed spatial rainfall patterns. We simulated eight ECL events using WRF with 36 model configurations, each comprising physics scheme combinations of two planetary boundary layer (pbl), two cumulus (cu), three microphysics (mp), and three radiation (ra) schemes. The performance of each physics scheme combination and the ensembles of multiple physics scheme combinations were evaluated separately. Results show that using the ensemble average gives higher skill than the median performer within the ensemble. More importantly, choosing a composite average of the better performing pbl and cu schemes can substantially improve the representation of high rainfall both spatially and quantitatively. 相似文献
13.
利用1980—2015年6—8月我国逐日降水观测数据评估CWRF模式（Climate-Weather Research and Forecasting model）多种参数化方案对我国夏季日降水的模拟能力,并考察累积概率变换偏差订正法（CDFt）的订正效果。通过将广义帕累托分布（GPD）引入到偏差订正模型中,提出针对极端降水的累积概率变换偏差订正法（XCDFt）,检验和评估其对极端降水订正的适用性。结果显示:CWRF模式微物理过程选用Morrison-aerosol参数化方案组合对我国降水场的模拟较好,CDFt订正效果良好;XCDFt偏差订正模型能够较好地提取模式建模与验证时期变化信号,订正后相比订正前与观测极端降水的概率分布更为接近;经过XCDFt订正后华南、华中和华北地区20年一遇的极端降水重现水平较模拟值更接近观测值,可为CWRF模式提高极端降水的业务预测水平提供参考。 相似文献
14.
When using the Weather Research and Forecasting (WRF) modelling system it is necessary to choose between many parametrisations for each physics option. This study examines the performance of various physics scheme combinations on the simulation of a series of rainfall events near the south-east coast of Australia known as East Coast Lows. A thirty-six member multi-physics ensemble was created such that each member had a unique set of physics parametrisations. No single ensemble member was found to perform best for all events, variables and metrics. This is reflected in the fact that different climate variables are found to be sensitive to different physical parametrisations. While a standardised super-metric can be used to identify best performers, a step-wise decision approach described here, allows explicit recognition of the “robustness” of choosing one parameterisation over another, allowing the identification of a group of “equally robustly” performing physics combinations. These results suggest that the Mellor-Yamada-Janjic planetary boundary layer scheme and the Betts-Miller-Janjic cumulus scheme can be chosen with some robustness. Possibly with greater confidence, the results also suggest that the Yonsei University planetary boundary layer scheme, Kain-Fritsch cumulus scheme and RRTMG radiation scheme should not be used in combination in this region. Results further indicate that the selection of physics scheme options has larger impact on model performance during the more intensive rainfall events. 相似文献
15.
Alejandro Di Luca Emmanouil Flaounas Philippe Drobinski Cindy Lebeaupin Brossier 《Climate Dynamics》2014,43(9-10):2349-2375
The use of high resolution atmosphere–ocean coupled regional climate models to study possible future climate changes in the Mediterranean Sea requires an accurate simulation of the atmospheric component of the water budget (i.e., evaporation, precipitation and runoff). A specific configuration of the version 3.1 of the weather research and forecasting (WRF) regional climate model was shown to systematically overestimate the Mediterranean Sea water budget mainly due to an excess of evaporation (~1,450 mm yr?1) compared with observed estimations (~1,150 mm yr?1). In this article, a 70-member multi-physics ensemble is used to try to understand the relative importance of various sub-grid scale processes in the Mediterranean Sea water budget and to evaluate its representation by comparing simulated results with observed-based estimates. The physics ensemble was constructed by performing 70 1-year long simulations using version 3.3 of the WRF model by combining six cumulus, four surface/planetary boundary layer and three radiation schemes. Results show that evaporation variability across the multi-physics ensemble (～10 % of the mean evaporation) is dominated by the choice of the surface layer scheme that explains more than ～70 % of the total variance and that the overestimation of evaporation in WRF simulations is generally related with an overestimation of surface exchange coefficients due to too large values of the surface roughness parameter and/or the simulation of too unstable surface conditions. Although the influence of radiation schemes on evaporation variability is small (～13 % of the total variance), radiation schemes strongly influence exchange coefficients and vertical humidity gradients near the surface due to modifications of temperature lapse rates. The precipitation variability across the physics ensemble (～35 % of the mean precipitation) is dominated by the choice of both cumulus (～55 % of the total variance) and planetary boundary layer (～32 % of the total variance) schemes with a strong regional dependence. Most members of the ensemble underestimate total precipitation amounts with biases as large as 250 mm yr?1 over the whole Mediterranean Sea compared with ERA Interim reanalysis mainly due to an underestimation of the number of wet days. The larger number of dry days in simulations is associated with a deficit in the activation of cumulus schemes. Both radiation and planetary boundary layer schemes influence precipitation through modifications on the available water vapor in the boundary layer generally tied with changes in evaporation. 相似文献
16.
Uncertainties in simulating the seasonal mean atmospheric water cycle in Equatorial East Africa are quantified using 58 one-year-long experiments performed with the Weather Research and Forecasting model (WRF). Tested parameters include physical parameterizations of atmospheric convection, cloud microphysics, planetary boundary layer, land-surface model and radiation schemes, as well as land-use categories (USGS vs. MODIS), lateral forcings (ERA-Interim and ERA40 reanalyses), and domain geometry (size and vertical resolution). Results show that (1) uncertainties, defined as the differences between the experiments, are larger than the biases; (2) the parameters exerting the largest influence on simulated rainfall are, in order of decreasing importance, the shortwave radiation scheme, the land-surface model, the domain size, followed by convective schemes and land-use categories; (3) cloud microphysics, lateral forcing reanalysis, the number of vertical levels and planetary boundary layer schemes appear to be of lesser importance at the seasonal scale. Though persisting biases (consisting of conditions that are too wet over the Indian Ocean and the Congo Basin and too dry over eastern Kenya) prevail in most experiments, several configurations simulate the regional climate with reasonable accuracy. 相似文献
17.
基于WRFV3.6.1,利用其8个云微物理参数化方案对2010—2016年华南汛期（4—9月）的6个南风型暖区暴雨个例进行数值模拟与多方案集成试验,并采用基于对象的诊断评估方法（MODE）对模拟结果进行评估。结果发现对于大多数个例,WRF模式都能较好地模拟出暖区暴雨的降水带,对暖区降水带模拟最好的参数化方案是WSM6方案,其次是Lin方案;模拟效果较差的参数化方案为CAM5.1与NSSL 2-mon方案。选取模拟结果较好的个例进行诊断分析,发现不同参数化方案得到的动力学特征以及云微物理特征相关变量存在较大差异,导致模拟降水的差异。在单方案模拟的基础上,开展多方案集成试验,发现多方案集成方法能够有效降低模式模拟的不确定性,产生更稳定的模拟结果。 相似文献