共查询到19条相似文献，搜索用时 421 毫秒
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为了进一步检验裸土参数化的气候模拟性能，本文在文献[1，2]的基础上，利用NCEP再分析资料和Xie等全球降水资料与CCM3模拟结果进行了对比。结果表明：加入裸土参数化方案的CCM3能较好地再现冬季东亚和中国地区区域气候的主要特征，模式较原CCM3能更好地模拟地表温度和东亚及中国西北地区的降水，对东亚季风环流的模拟也较接近实际。同时，该方案在CCM3中的加入改进了青藏高原冬季降雪带及夏季高原东南部降水中心的模拟，提高了模式对高原冬夏季降水的模拟能力，从而再次说明利用观测资料对模式参数修正及参数化方法的改进是提高数值模式模拟能力的一个重要途径。 相似文献
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SHAW模式的改进及其在黄土高原半干旱区的模拟研究 总被引：1，自引：0，他引：1
陆面过程模拟研究中的一个关键问题是如何准确的计算陆气间能量交换,但现有的陆面过程模式模拟的湍流通量与观测值间仍然存在较大偏差,因此改进湍流通量的参数化方案对于提高陆面过程模式模拟能力有重要意义。本研究通过改进陆面过程模式SHAW中的热力粗糙度方案,以及引入干表层蒸发方案,以期改善湍流通量的模拟能力。在此基础上利用黄土高原半干旱区SACOL站观测资料,进行模式改进前后的单点模拟对比试验,研究其参数化方案改进对陆面过程模拟的影响。结果表明:改进后的SHAW模式能够合理地模拟黄土高原半干旱区陆面特征的变化趋势,模拟值与观测值偏差较小。与原来的SHAW模式模拟结果相比,改进后的SHAW_MOD模式显著提高了湍流通量的模拟能力,并改善了净辐射和深层土壤温度的模拟,但对土壤湿度的改进并不明显,这可能与土壤内部水热传输过程及相关参数化方案有关,还有待做进一步研究。 相似文献
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西北干旱区荒漠戈壁陆面过程的数值模拟 总被引：13，自引：0，他引：13
首先利用“中国西北干旱区陆 气相互作用试验”2 0 0 0年 5～ 6月在甘肃敦煌进行的陆 气相互作用野外试验的观测资料 ,确定了西北干旱区荒漠戈壁的陆面过程参数 ,并用这些参数改进了已有的陆面过程模式。然后用该陆面过程模式对敦煌陆 气相互作用野外试验荒漠戈壁上的大气感热通量、潜热通量、摩擦速度以及净辐射、地表和土壤温度、土壤水份等重要陆面变量进行了模拟 ,结果表明 ,模拟值与观测值非常接近 ,这说明改进后的模式对干旱区陆面过程有较强的模拟能力 相似文献
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一种区域气候模式地表产流方案的改进及数值试验 总被引：1，自引：8，他引：1
本文针对陆面过程模式BATS中没有水文非均匀描述的这一缺陷,将更符合物理过程实际的考虑入渗非均匀和降水非均匀的水文模型VXM并入BATS,并将此改进后的陆面过程参数化方案与MM5V3耦合。利用该区域水文气候模式模拟1990、1991和1998年夏季风气候,对模拟结果分析得知,总体上该模式的模拟能力对入渗非均匀和降水非均匀的响应是敏感的,而且考虑入渗非均匀和降水非均匀后模式的模拟能力得到了一定的提高。 相似文献
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为了改进美国NCAR CCM3全球模式中LSM陆面模型中的积雪方案的模拟效果，在Sun等SAST积雪模型的基础上，作了部分修改后，加进CCM3模式LSM模型中。该方案根据格点区域平均积雪深度的不同，把地面雪盖划分为1到3层不等，能在积雪表层和中间层更好地描述温度的日变化和季节变化；较详细地考虑了雪的热传导、太阳辐射的穿透吸收、雪的融化、液态水的储存、渗透和再冻结等积雪内部的主要物理过程；根据Nimbus-7卫星实测雪深资料修改了积雪覆盖度和雪面反照率的计算方案。利用前苏联6个台站1978—1983年的实测积雪资料和大气强迫数据，进行了单点模拟试验，结果表明，新的积雪参数化方案能够较好地再现积雪深度和雪水当量的逐日和季节变化特征，部分提高了积雪参数化方案对积雪的模拟能力。 相似文献
6.
《高原气象》2017,(4)
陆面过程模式中输入参数的不确定性会引起模式模拟偏差。为了改善模式的模拟能力,减小参数的不确定性,通常要进行参数优化过程。利用温江站观测的近地层资料,结合粒子群优化算法(Particle Swarm Optimization,PSO),优化了陆面过程模式SHAW(Simultaneous Heat and Water)中难以直接观测的土壤和植被参数。在此基础上,分别利用优化后的参数和默认参数运行SHAW模式,模拟该地区陆面过程特征,并与观测值进行对比,研究优化参数后对陆面过程模拟的影响。结果表明:利用PSO算法优化SHAW模式后,能提高土壤湿度和潜热通量的模拟性能,模拟的土壤湿度和潜热通量与相应的观测值偏差减小。但与此同时,并没有改进净辐射、土壤温度和感热通量的模拟性能。说明PSO算法可以用于陆面模式参数优化,但仅仅通过参数优化并不能同时提高所有变量的模拟性能。 相似文献
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陆面模式CLSM的设计及性能检验II.模式检验 总被引：5，自引：1，他引：4
利用BOREAS,HEIFE,ARME,GAME-TIPEX等大量的陆面外场观测资料,针对不同类型的陆面过程,对所发展的陆面模式CLSM的性能进行检验.模拟结果与观测资料的对比分析表明:一方面,CLSM能够对积雪变化、干旱/半干旱地区的水热交换等特殊的陆面过程进行合理的描述;另一方面,CLSM对热带雨林地区的植被-大气相互作用、高原地气交换过程同样具有很强的模拟能力.CLSM解决了陆面模式对上述特殊下垫面描述能力有限的实际问题,保证了对特殊下垫面进行合理描述的同时,又保证了对其他不同陆面状况的模拟能力.CLSM改善了陆面模式对全球范围内不同下垫面条件下的陆面过程及地-气交换过程的模拟能力. 相似文献
8.
将BATS1e (Biosphere-Atmosphere Transfer Scheme version 1e) 陆面模式与p-σ九层区域气候模式(PσRCM9) 进行耦合，发展了一个包含有更复杂陆－气相互作用的区域气候模式(BATS1e-PσRCM9)。通过对东亚地区1月和7月气候平均场和1991年江淮流域梅雨期间三次强降水过程的数值模拟，考察了BATS1e陆面模式对PσRCM9模式模拟性能的影响。数值试验结果表明，BATS1e-PσRCM9模式对东亚区域冬、 夏季气候平均场的模拟能力有明显提高，且对近地层和对流层低层各气象要素场模拟效果的改善比对流层中高层更加明显。与PσRCM9模式的模拟结果相比，BATS1e-PσRCM9模式对中国东南部地区降水的模拟与观测更为一致，并且对江淮流域梅雨期间的强降水过程也有较好的模拟能力。由于BATS1e-PσRCM9模式改进了地气之间动量、热量和水汽通量交换的计算，更好地描述了陆地下垫面与大气之间的相互作用，从而改善了模式对近地层各气象要素场的模拟。因此，通过耦合BATS1e陆面模式能较明显地提高PσRCM9模式模拟东亚区域短期气候变化的能力，这为区域气候模式的进一步发展奠定了基础。 相似文献
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DING Yihui SHI Xueli LIU Yiming LIU Yan LI Qingquan QIAN Yongfu MIAO Manqian ZHAI Guoqing GAO Kun 《大气科学进展》2006,23(3)
A modified version of the NCAR/RegCM2 has been developed at the National Climate Center (NCC), China Meteorological Administration, through a series of sensitivity experiments and multi-year simulations and hindcasts, with a special emphasis on the adequate choice of physical parameterization schemes suitable for the East Asian monsoon climate. This regional climate model is nested with the NCC/IAP (Institute of Atmospheric Physics) T63 coupled GCM to make an experimental seasonal prediction for China and East Asia. The four-year (2001 to 2004) prediction results are encouraging. This paper is the first part of a two-part paper, and it mainly describes the sensitivity study of the physical process parameterization represented in the model. The systematic errors produced by the different physical parameterization schemes such as the land surface processes, convective precipitation, cloud-radiation transfer process, boundary layer process and large-scale terrain features have been identified based on multi-year and extreme flooding event simulations. A number of comparative experiments has shown that the mass flux scheme (MFS) and Betts-Miller scheme (BM) for convective precipitation, the LPMI (land surface process model I) and LPMII (land surface process model Ⅱ) for the land surface process, the CCM3 radiation transfer scheme for cloud-radiation transfer processes, the TKE (turbulent kinetic energy) scheme for the boundary layer processes and the topography treatment schemes for the Tibetan Plateau are suitable for simulations and prediction of the East Asia monsoon climate in rainy seasons. Based on the above sensitivity study, a modified version of the RegCM2 (RegCM_NCC) has been set up for climate simulations and seasonal predictions. 相似文献
12.
A modified version of the NCAR/RegCM2 has been developed at the National Climate Center （NCC）, China Meteorological Administration, through a series of sensitivity experiments and multi-year simulations and hindcasts, with a special emphasis on the adequate choice of physical parameterization schemes suitable for the East Asian monsoon climate. This regional climate model is nested with the NCC/IAP （Institute of Atmospheric Physics） T63 coupled GCM to make an experimental seasonal prediction for China and East Asia. The four-year （2001 to 2004） prediction results are encouraging. This paper is the first part of a two-part paper, and it mainly describes the sensitivity study of the physical process paraxneterization represented in the model. The systematic errors produced by the different physical parameterization schemes such as the land surface processes, convective precipitation, cloud-radiation transfer process, boundary layer process and large-scale terrain features have been identified based on multi-year and extreme flooding event simulations. A number of comparative experiments has shown that the mass flux scheme （MFS） and Betts-Miller scheme （BM） for convective precipitation, the LPMI （land surface process model I） and LPMII （land surface process model Ⅱ） for the land surface process, the CCM3 radiation transfer scheme for cloud-radiation transfer processes, the TKE （turbulent kinetic energy） scheme for the boundary layer processes and the topography treatment schemes for the Tibetan Plateau are suitable for simulations and prediction of the East Asia monsoon climate in rainy seasons. Based on the above sensitivity study, a modified version of the RegCM2 （RegCM_NCC） has been set up for climate simulations and seasonal predictions. 相似文献
13.
土地利用变化对我国区域气候影响的数值试验 总被引：29，自引：0，他引：29
使用RegCM2区域气候模式单向嵌套澳大利亚CSIRO R21L9全球海-气耦合模式,通过将中国区域植被覆盖由理想状况改变为实际状况的数值试验对比分析,探讨了当代中国土地利用变化对中国区域气候的影响,并对结果进行了统计显著性检验。研究表明,土地利用的变化,会导致我国西北等地区年平均降水减少,导致年平均气温在内陆部分地区升高和在沿海个别地区降低,引起许多地方夏季日平均最高气温升高,而冬季日平均最低气温则在我国东部部分地区降低的同时在西北地区升高,土壤湿度的变化表现为大范围的降低。研究同时表明,相同的土地变化在不同的地理环境下引起的气候要素变化有一定的不一致性。 相似文献
14.
Andrew J.PITMAN 《大气科学进展》2005,(1)
A series of 17-yr equilibrium simulations using the NCAR CCM3 (T42 resolution) were performed to investigate the regional scale impacts of land cover change and increasing CO2 over China. Simulations with natural and current land cover at CO2 levels of 280, 355, 430, and 505 ppmv were conducted. Results show statistically significant changes in major climate fields (e.g. temperature and surface wind speed) on a 15-yr average following 相似文献
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The Relative Impact of Regional Scale Land Cover Change and Increasing CO2 over China 总被引：2，自引：0，他引：2
A series of 17-yr equilibrium simulations using the NCAR CCM3 (T42 resolution) were performed to investigate the regional scale impacts of land cover change and increasing CO2 over China. Simulations with natural and current land cover at CO2 levels of 280,355, 430, and 505 ppmv were conducted. Results show statistically significant changes in major climate fields (e.g. temperature and surface wind speed) on a 15-yr average following land cover change. We also found increases in the maximum temperature and in the diurnal temperature range due to land cover change. Increases in CO2 affect both the maximum and minimum temperature so that changes in the diurnal range are small. Both land cover change and CO2 change also impact the frequency distribution of precipitation with increasing CO2 tending to lead to more intense precipitation and land cover change leading to less intense precipitation-indeed, the impact of land cover change typically had the opposite effect versus the impacts of CO2. Our results provide support for the inclusion of future land cover change scenarios in long-term transitory climate inodelling experiments of the 21st Century. Our results also support the inclusion of land surface models that can represent future land cover changes resulting from an ecological response to natural climate variability or increasing CO2. Overall, we show that land cover change can have a significant impact on the regional scale climate of China, and that regionally, this impact is of a similar magnitude to increases in CO2 of up to about 430 ppmv. This means that that the impact of land cover change must be accounted for in detection and attribution studies over China. 相似文献
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土壤湿度对东亚夏季气候潜在可预报性影响的数值模拟 总被引：5，自引：0，他引：5
利用全球大气环流模式NCARCAM3进行了在给定的观测海温条件下的22a（1979—2000年）5—8月的2组集合试验。运用方差分析方法,分析了在气候态和年际变化的表层土壤湿度情况下,CAM3模式模拟的东亚夏季气候潜在可预报性及其差异。结果表明：在给定的观测海温条件下,采用气候态的土壤湿度时,CAM3模式模拟的东亚夏季气候的潜在可预报性偏低;而采用年际变化的土壤湿度时,模拟的夏季气候潜在可预报性有所提高,尤其是在中国西北地区;后者模拟的中国西北地区夏季降水和气温的潜在可预报性比前者的模拟结果提高0．1以上。其原因可能是：采用年际变化的土壤湿度时,模式可以更好地模拟出中国西北地区的地表蒸发量和湍流热通量的年际变化,进而使得模式对该地区夏季气候的预报技巧得到提高。 相似文献
17.
基于多源陆面通量数据相融合的新资料及其在中国夏季风影响过渡区的应用 总被引：1，自引：0，他引：1
夏季风影响过渡区是陆面能量交换与区域气候相互作用显著的热点区域。然而,目前缺乏适用于该区域的高精度长期通量数据集,这限制了陆面水热交换与气候相互作用的研究。如何融合目前已有的多源通量资料进行重构建以及应用显得十分必要。本研究综合包括中国北方协同观测试验和中国通量网的多种下垫面通量观测以及多种格点资料,试图重构中国夏季风影响过渡区的陆面能量通量数据集。在筛选具有优良下垫面代表性站点并考察模拟和观测散点分布规律的基础上,利用多元回归模型构建了一套适用于夏季风影响过渡区并且受观测资料约束的月平均感热、潜热和净辐射数据集。交叉验证结果表明构建的数据集相对于几种原始格点数据集精度有一定提高,最大程度上消除了原始格点资料的系统偏差。进一步分析表明在地表能量平衡分量中,陆面湍流通量对夏季风的响应更为显著,并且夏季风影响过渡区陆面湍流热通量对夏季风持续时间呈现对数分布的年际变化规律;当夏季风处于低持续影响状态时陆面湍流热通量年际变化更为显著,偏弱的夏季风系统可能导致陆面过程对气候变化更强的影响。本文基于多源通量数据融合构建的新数据集可以为气候变化研究提供数据支撑,同时增加了对陆面过程与季风系统相互作用的认识。 相似文献
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Comparison of the climate simulated by the CCM3 coupled to two different land-surface models 总被引：5，自引：0，他引：5
We present results from a coupled atmosphere-biosphere model CCM3/IBIS (the Community Climate Model coupled to the Integrated BIosphere Simulator), which is designed to study the dynamic interactions between climate and vegetation and the global carbon cycle. We analyze the climate simulated by CCM3/IBIS with fixed vegetation conditions and we compare it to the climate simulated by the standard CCM3, which includes the LSM (land surface model) land-surface package. Important differences between the two models include simple parametrizations of lakes, wetlands and crops in CCM3/LSM not taken into account in CCM3/IBIS. CCM3/IBIS and CCM3/LSM share common biases (compared to observations) in the temperature field in boreal winter and in the precipitation field annually, making the atmospheric model the most probable cause of those biases. The models differ in the temperature field and surface energy balance in the Sahara annually and in the mid-to high latitudes from spring through fall. CCM3/IBIS simulates global annual air temperatures that are on average 1.7 °C higher than CCM3/LSM and 0.5 °C higher than the observed climatology. Differences in albedo and/or snow parametrization explain most of the Sahara and high-latitude temperature disagreement. Our sensitivity study with CCM3/LSM shows that the presence of lakes and wetlands in CCM3/LSM can account for about half of the difference in temperature in summer over the lake and wetland regions of the mid-latitudes. A second sensitivity study shows that higher surface roughness length in CCM3/IBIS can also explain part of the difference in summer surface temperature in the mid-latitudes. Surface roughness length affects the surface temperature through a feedback mechanism linking surface wind speed, planetary boundary layer height, low level cloudiness and radiation 相似文献
19.
Haixia Duan Yaohui Li Tiejun Zhang Zhaoxia Pu Cailing Zhao Yuanpu Liu 《Acta Meteorologica Sinica》2018,32(3):469-490
This study investigated the performance of the mesoscale Weather Research and Forecasting (WRF) model in predicting near-surface atmospheric temperature and wind for a complex underlying surface in Northwest China in June and December 2015. The spatial distribution of the monthly average bias errors in the forecasts of 2-m temperature and 10-m wind speed is analyzed first. It is found that the forecast errors for 2-m temperature and 10-m wind speed in June are strongly correlated with the terrain distribution. However, this type of correlation is not apparent in December, perhaps due to the inaccurate specification of the surface albedo and freezing–thawing process of frozen soil in winter in Northwest China in the WRF model. In addition, the WRF model is able to reproduce the diurnal variation in 2-m temperature and 10-m wind speed, although with weakened magnitude. Elevations and land-use types have strong influences on the forecast of near-surface variables with seasonal variations. The overall results imply that accurate specification of the complex underlying surface and seasonal changes in land cover is necessary for improving near-surface forecasts over Northwest China. 相似文献