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1.
Annett Wolf Eleanor Blyth Richard Harding Daniela Jacob Elke Keup-Thiel Holger Goettel Terry Callaghan 《Climatic change》2008,87(1-2):75-89
We tested the sensitivity of a dynamic ecosystem model (LPJ-GUESS) to the representation of soil moisture and soil temperature
and to uncertainties in the prediction of precipitation and air temperature. We linked the ecosystem model with an advanced
hydrological model (JULES) and used its soil moisture and soil temperature as input into the ecosystem model. We analysed
these sensitivities along a latitudinal gradient in northern Russia. Differences in soil temperature and soil moisture had
only little influence on the vegetation carbon fluxes, whereas the soil carbon fluxes were very sensitive to the JULES soil
estimations. The sensitivity changed with latitude, showing stronger influence in the more northern grid cell. The sensitivity
of modelled responses of both soil carbon fluxes and vegetation carbon fluxes to uncertainties in soil temperature were high,
as both soil and vegetation carbon fluxes were strongly impacted. In contrast, uncertainties in the estimation of the amount
of precipitation had little influence on the soil or vegetation carbon fluxes. The high sensitivity of soil respiration to
soil temperature and moisture suggests that we should strive for a better understanding and representation of soil processes
in ecosystem models to improve the reliability of predictions of future ecosystem changes. 相似文献
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Yonghui Yang Masataka Watanabe Zhiping Wang Yasuo Sakura Changyuan Tang 《Climatic change》2003,57(1-2):163-183
The WAVES model was used to simulate the effect of global warming on soil moisture on the semi-arid Taihang Mountain in China. Parameters of the WAVES model were first adjusted according to soil moisture data from a field global warming experiment. Then, the reliability of WAVES in predicting soil moisture changes induced by climatic change was confirmed by comparing the simulated and observed soil moisture values under different climatic conditions and plant growth rates of another field treatment. Next, 10 climate change scenarios incorporating increases in temperature and changes in precipitation were designed. When a simulation was conducted using the leaf area index (LAI) growth pattern from a field experiment under the present climatic conditions, the results suggested that the combination of temperature increase and precipitation decrease would greatly decrease soil water content throughout the entire simulation period. On the other hand, only when precipitation increased by 20% and temperatureincreased by 2 °C, the effect of precipitation increase on soil moisture was obviously positive. Although soil moisture conditions in the T2P1 (temperature increase by 2 °C and precipitation increase by 10%) and T4P2 (temperature increase by 4 °C and precipitation increase by 20%) scenarios were slightly better during the rainy season and notmuch changed before the rainy season, the positive effect of 10%precipitation increase on soil moisture was totally offset by moisture decrease caused bya 4 °C temperature increase in the T4P1 scenario. At the same time, the trends of soil-moisture change were highly coincident with predicted changes in productivity. Finally, the predicted LAI values from other studies were combined with the climatic change scenarios and used in the simulation. The results showed that changes in LAI alleviated, at least to some extent, the effects of temperature and precipitation changes on soil moisture. 相似文献
4.
我国夏季降水及相关大气环流场未来变化的预估及不确定性分析 总被引：8，自引：1，他引：7
利用政府间气候变化专门委员会第四次评估报告(IPCCAR4)的15个耦合气候模式在不同排放情景下的模拟结果,对我国夏季降水及相关大气环流场的未来时空变化特征与模式之间的不确定性作了研究。结果表明,在全球变暖背景下,我国夏季降水表现出较强的局地特征。其中,我国东部和高原地区的降水在21世纪表现出明显的增加趋势,而且这种趋势随着变暖的加剧而增强,同时模式模拟结果之间的一致性也更好,表明这一结果的可信度较高。在全球变暖背景下,我国新疆南部地区表现为持续的降水减少趋势,而我国西南地区夏季降水的变化则呈现出先减少(21世纪初)后增加的特征,不同模式对降水这些局地特征的模拟也都表现出较好的一致性。其他地区夏季降水在21世纪的变化不大,同时模式模拟的一致性也较差。多模式模拟的我国未来百年夏季降水的这些变化特征在温室气体高、中、低不同排放情景下基本一致,A2情景预估结果变化最大,A1B次之,B1相对最小。东亚夏季大气环流场的预估结果显示,在全球变暖的背景下,大部分模式的模拟结果都表明,东亚夏季风环流有所增强,从而使得由低纬度大洋和南海地区向我国大陆的水汽输送增加,造成该地区大气含水量的增多,从而为我国东部地区夏季降水的增加提供有利条件。此外,随着全球变暖的加剧,西太平洋副热带高压持续增强,其变化对我国东部地区夏季降水的影响程度和范围也明显增大。这些环流场及其不确定性的分析结果进一步加强了我国夏季降水未来变化预估结果的可信度。 相似文献
5.
21世纪珠江流域水文过程对气候变化的响应 总被引：4，自引：0，他引：4
应用HBV-D水文模型和多个气候模式预估了不同温室气体排放情景下珠江主干流西江的径流过程,分析了21世纪水资源量和洪水频率的变化。结果表明：2050年后年降水量和年径流量较基准期（1961—1990年）明显增加;流域平均的月降水量和径流量在5—10月间均呈增加趋势,12月至次年2月呈减少趋势;年最大1 d和7 d洪量逐渐增加,重现期逐渐缩短。2030年前枯水期径流增加有望缓解枯水期用水压力,而2050年之后丰水期径流量以及洪水强度、发生频率的增加将给珠江流域防汛抗洪带来更大压力,在制订气候变化对流域水资源影响适应性对策时应考虑这两方面的影响。 相似文献
6.
利用中国科学院西北生态环境资源研究院玛曲土壤温湿观测网2008-2009年、2013-2014年数据验证了3套再分析资料ERA-Interim,CFSR（Climate Forecast System Reanalysis）和JRA-55（Japanese 55-year Reanalysis）在黄河源区的适用性,结合中国气象数据网玛曲气象站1980-2014年观测资料与CLM4.5（Community Land Model 4.5）进一步分析了黄河源区近35年气候变迁、土壤温湿分布和变化,结果表明:CFSR能够较好地描绘黄河源区土壤湿度变化,ERA-Interim对于土壤温度刻画能力更强,JRA-55效果较差;35年来气温、土壤温湿总体呈上升趋势且发生突变;近年来10 cm土壤温湿有暖干化趋势,降水量稍有增加,土壤冷季冻结周期变短,暖季持续时间拉长;CLM4.5模拟精度高,能够较好地刻画源区土壤温湿变化细节,两湖及黄河周边暖季为冷湿中心,冷季为暖干中心。 相似文献
7.
This paper assesses the impacts of climate change on water resources in the upper Ping River Basin of Thailand. A rainfall-runoff model is used to estimate future runoff based on the bias corrected and downscaled ECHAM4/OPYC general circulation model (GCM) precipitation scenarios for three future 5-year periods; the 2023–2027 (2025s), the 2048–2052 (2050s) and 2093–2097 (2095s). Bias-correction and spatial disaggregation techniques are applied to improve the characteristics of raw ECHAM4/OPYC precipitation. Results of future simulations suggest a decrease of 13–19 % in annual streamflow compared to the base period (1998–2002). Results also indicate that there will be a shift in seasonal streamflow pattern. Peak flows in future periods will occur in October–November rather than September as observed in the base period. There will be a significant increase in the streamflow in April with overall decrease in streamflow during the rainy season (May–October) and an increase during the dry season (November–April) for all future time periods considered in the study. 相似文献
8.
基于土壤湿度融合分析产品及气象观测资料,分析了青藏高原及其典型区域的土壤湿度分布特征以及影响因素.结果表明：青藏高原土壤湿度与高原降水季节有较好的对应关系,降水量多的季节对应大的土壤湿度,反之亦然,即夏季土壤湿度最大,春季和秋季次之,冬季最小;高原外围土壤相对较湿,中部较干,夏季土壤高湿度区从藏东南向西北、塔里木盆地向藏东北扩展,冬季土壤高湿度区向藏东南和塔里木盆地收缩;土壤湿度垂直层次呈现出浅层和深层低、中间层高的特点,从浅层到深层土壤湿度的变化幅度逐渐减小;高原典型区域土壤湿度逐日变化规律与高原区域平均的土壤湿度时间演变接近一致,降水量的多少和湿润区、半干旱区土壤湿度高低值有较好的对应关系,湿润区垂直梯度大,干旱区和半干旱区垂直梯度小;蒸发量、风速、气温以及植被状况均会影响到土壤湿度的分布特征. 相似文献
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10.
采用新安江月分布式水文模型, 结合1961—2000年历史月气候资料和4个CGCMs的3个SRES排放情景下 (B1, A 2, A 1B) 未来降水和气温情景模拟结果, 对过去淮河流域的径流进行模拟检验并对未来2011—2040年的径流影响进行评估, 为水资源管理和规划提供依据。结果表明:水文模型能较好地反映年、月流量以及多年平均值和季节的变化; 年流量模拟一般好于月流量, 淮河干流主要控制水文站如王家坝、鲁台子、蚌埠的年流量模型效率系数均在80%以上; 多年平均值模拟效果好, 平均绝对相对误差为10%。多数CGCMs不同排放情景下气候模拟结果表明:未来2011—2040年, 淮河流域气候将趋于暖湿, 但年径流量将可能以减少趋势为主。这对淮河地区水资源的可持续发展以及东线调水工程水资源统一调配和管理提出了较大的挑战。淮河流域大部分区域2011—2040年月径流量减少将主要发生在1月和7—12月, 变化趋势较为确定; 4—6月, 径流量将以增加趋势为主, 不确定性较大; 2—3月, 径流具有增加趋势的地区多分布在淮河以北地区, 具有减少趋势的地区则多分布在淮河干流及以南地区和洪泽湖、平原区, 这些地区增加或减少趋势的不确定性较大。 相似文献
11.
Agricultural drought in a future climate: results from 15 global climate models participating in the IPCC 4th assessment 总被引：8，自引：0，他引：8
Guiling Wang 《Climate Dynamics》2005,25(7-8):739-753
This study examines the impact of greenhouse gas warming on soil moisture based on predictions of 15 global climate models
by comparing the after-stabilization climate in the SRESA1b experiment with the pre-industrial control climate. The models
are consistent in predicting summer dryness and winter wetness in only part of the northern middle and high latitudes. Slightly
over half of the models predict year-round wetness in central Eurasia and/or year-round dryness in Siberia and mid-latitude
Northeast Asia. One explanation is offered that relates such lack of seasonality to the carryover effect of soil moisture
storage from season to season. In the tropics and subtropics, a decrease of soil moisture is the dominant response. The models
are especially consistent in predicting drier soil over the southwest North America, Central America, the Mediterranean, Australia,
and the South Africa in all seasons, and over much of the Amazon and West Africa in the June–July–August (JJA) season and
the Asian monsoon region in the December–January–February (DJF) season. Since the only major areas of future wetness predicted
with a high level of model consistency are part of the northern middle and high latitudes during the non-growing season, it
is suggested that greenhouse gas warming will cause a worldwide agricultural drought. Over regions where there is considerable
consistency among the analyzed models in predicting the sign of soil moisture changes, there is a wide range of magnitudes
of the soil moisture response, indicating a high degree of model dependency in terrestrial hydrological sensitivity. A major
part of the inter-model differences in the sensitivity of soil moisture response are attributable to differences in land surface
parameterization. 相似文献
12.
土壤湿度是陆面过程的重要参量,可以通过影响土壤本身的热力性质和水文过程,导致局部大气环流的改变以及区域性短期气候异常。青藏高原作为全球气候变化的敏感区,其地气间的水分与能量交换对亚洲季风和全球大气循环有着极大的影响,且高原地区的土壤水分数据能够为陆-气相互作用和数值模拟等研究提供重要的观测信息和初始输入数据。文中综述了青藏高原土壤湿度观测和研究对气候变化影响的重要性,高原土壤湿度观测站网建设现状,各种土壤湿度替代资料的适用性和评估研究,以及高原土壤湿度时空分布特征对降水的影响与气候变化响应,并提出了今后青藏高原土壤湿度研究着重解决的问题。 相似文献
13.
土壤湿度影响中国夏季气候的数值试验 总被引：10，自引：0，他引：10
利用"全球土壤湿度计划第2阶段"提供的土壤湿度资料强迫区域气候模式RegCM3,通过数值试验讨论了土壤湿度对东亚夏季气候模拟效果的影响。结果表明,合理考虑土壤湿度的作用,能够提高区域气候模式对中国夏季降水和2 m气温的空间分布型及逐日变化的模拟效果;模拟结果与观测的相关分析显示,降水和2 m气温的年际变化都得到了有效改进,这种改进在气温上尤为明显。不过上述改进具有区域依赖性。数值试验结果表明,气温对土壤湿度的敏感性强于降水,这也从一个侧面说明提高降水模拟效果的难度。总体而言,合理的土壤湿度能够提高区域气候模式对中国夏季气候的模拟能力。因此,合理描述土壤湿度的变化,是提高中国夏季气候预报技巧的潜在途径之一。 相似文献
14.
山西地处气候过渡带,气候敏感、生态脆弱,在全球气候变暖背景下其陆面物理过程受气候波动影响十分明显。本文利用NCAR CCSM IPCC AR4陆面分量模式(CLM)20世纪气候模拟(20C3M)和21世纪SRES A1B排放情景下的模拟结果,对山西省21世纪(2001~2099年)与20世纪(1901~1999年)陆面能量和水文变量进行了对比分析。结果显示:(1)模式模拟出山西地区未来地面温度的空间及时间分布特征。未来山西省地面温度呈明显上升趋势,上升速率冬季大于夏季。空间上,增温幅度冬季自北向南递减,夏季自西向东递减;(2)未来山西省陆面各分量空间上,净辐射通量西北增幅大于东南,降水率和径流率则与其相反,潜热通量与蒸发率一致,西南部增加幅度大,土壤含水率冬夏分布相反,感热通量呈下降趋势,西南下降幅度大;时间上,净辐射通量、潜热通量均表现出不同程度的上升趋势,土壤热通量冬季上升,夏季下降;地表水循环的各分量均呈增加趋势。 相似文献
15.
西北干旱区感热异常对中国夏季降水影响的模拟 总被引：12，自引：0，他引：12
利用最新版的RegCM3模式通过增加西北干旱区地面向大气的感热输送,模拟了西北干旱区春、夏季感热异常对中国夏季降水的影响。结果表明:西北地区地面向大气的感热输送增加后,西北干旱区低层空气温度升高,空气密度减小使得空气有上升运动距平,减弱了空气的下沉运动,从而在新疆地区降水增加。西北地区下沉气流减弱使得高空气压更强,形成反气旋气流距平,导致高原地区上升气流减弱,在青藏高原降水减少。高原地区上升气流减弱导致在长江中下游和东北北部分别有负的气压距平中心,使得这里有气旋式距平环流,降水增加;而在华南、西南、华北南部和东北南部降水减少。 相似文献
16.
Mukand S. Babel Shyam P. Bhusal Shahriar M. Wahid Anshul Agarwal 《Theoretical and Applied Climatology》2014,115(3-4):639-654
This paper characterizes potential hydrological impact of future climate in the Bagmati River Basin, Nepal. For this research, basinwide future hydrology is simulated by using downscaled temperature and precipitation outputs from the Hadley Centre Coupled Model, version 3 (HadCM3), and the Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS). It is predicted that temperature may rise maximally during the summer rather than winter for both A2 and B2 Special Report on Emissions Scenarios (SRES) scenarios. Precipitation may increase during the wet season, but it may decrease during other seasons for A2 scenario. For B2 scenario, precipitation may increase during all the seasons. Under the A2 scenario, premonsoon water availability may decrease more in the upper than the middle basin. During monsoons, both upper and middle basins show increased water availability. During the postmonsoon season, water availability may decrease in the upper part, while the middle part shows a mixed trend. Under the B2 scenario, water availability is expected to increase in the entire basin. The analysis of the projected hydrologic impact of climate change is expected to support informed decision-making for sustainable water management. 相似文献
17.
Jeffrey C. Rogers 《Climate Dynamics》2013,40(1-2):341-352
Portions of the southern and southeastern United States, primarily Mississippi, Alabama, and Georgia, have experienced century-long (1895–2007) downward air temperature trends that occur in all seasons. Superimposed on them are shifts in mean temperatures on decadal scales characterized by alternating warm (1930s–1940s, 1990s) and cold (1900s; 1960s–1970s) regimes. Regional atmospheric circulation and SST teleconnection indices, station-based cloud cover and soil moisture (Palmer drought severity index) data are used in stepwise multiple linear regression models. These models identify predictors linked to observed winter, summer, and annual Southeastern air temperature variability, the observed variance (r2) they explain, and the resulting prediction and residual time series. Long-term variations and trends in tropical Pacific sea temperatures, cloud cover, soil moisture and the North Atlantic and Arctic oscillations account for much of the air temperature downtrends. Soil moisture and cloud cover are the primary predictors of 59.6 % of the observed summer temperature variance. While the teleconnections, cloud cover and moisture data account for some of the annual and summer Southeastern cooling trend, large significant downward trending residuals remain in winter and summer. Comparison is made to the northeastern United States where large twentieth century upward air temperature trends are driven by cloud cover increases and Atlantic Multidecadal Oscillation (AMO) variability. Differences between the Northeastern warming and the Southeastern cooling trends in summer are attributable in part to the differing roles of cloud cover, soil moisture, the Arctic Oscillation and the AMO on air temperatures of the 2 regions. 相似文献
18.
潮白河流域为北京主要供水源,其水资源量对北京用水保障至关重要,因此开展该流域在全球1.5℃和2.0℃升温下的径流预估研究具有现实意义。利用1961—2001年WATCH数据对SWAT水文模型进行率定和验证,在此基础上,应用第五次耦合模式比较计划(CMIP5)中5个全球气候模式在典型浓度路径(RCP4.5、RCP6.0和RCP8.5)下预估的全球1.5℃和2.0℃升温下的数据驱动SWAT模型,开展了潮白河流域气温、降水及径流量的变化预估研究,并量化评估由气候模式和RCPs导致的水文效应的不确定性。结果表明：(1) SWAT模型基本能较好地模拟潮白河流域的月径流特征,应用该模型进行气候变化对径流量的影响评估是可行的。(2)在全球1.5℃和2.0℃升温下,潮白河流域年平均温度较基准期(1976—2005年)分别增加1.5℃和2.2℃,年平均降水量也增加4.9%和7.0%。预估的年径流量在全球1.5℃升温下总体略有增加,盛夏和秋初的径流量占全年的比例也有所增加;在全球2.0℃升温下,年径流量增幅达30%以上,但夏季径流量占全年的比例明显减少。(3)在全球2.0℃升温下,潮白河流域极端丰水流量明显增加,洪涝发生风险增大。(4)未来气温、降水量和径流量的预估都存在一定的不确定性,在全球2.0℃升温下不确定性更大;相对而言,径流量的不确定性要远大于降水量的不确定性;无论是全球1.5℃升温下还是2.0℃升温下,预估不确定性主要来源于全球气候模式。 相似文献
19.
Anushiya Jeganathan Ramachandran Andimuthu 《Theoretical and Applied Climatology》2013,114(3-4):705-714
This paper describes the projection of climate change scenarios under increased greenhouse gas emissions, using the results of atmospheric-ocean general circulation models in the Coupled Model Intercomparison Project phase 3 dataset. A score is given to every model based on global and regional performance. Four out of 20 general circulation models (GCMs) were selected based on skill in predicting observed annual temperature and precipitation conditions. The ensemble of these four models shows superiority over the individual model scores. These models were subjected to increases in future anthropogenic radiative forcings for constructing climate change scenarios. Future climate scenarios for Tamil Nadu were developed with MAGICC/SCENGEN software. Model results show both temperature and precipitation increases under increased greenhouse gas scenarios. Northeast and northwest parts of Tamil Nadu show a greater increase in temperature and precipitation. Seasonally, the maximum rise in temperature occurred during the MAM season, followed by DJF, JJA, and SON. Decreasing trends of precipitation were observed during DJF and MAM. 相似文献
20.
Trends and scales of observed soil moisture variations in China 总被引：3，自引：0，他引：3
A new soil moisture dataset from direct gravimetric measurements within the top 50-cm soil layers at 178 soil moisture stations in China covering the period 1981-1998 are used to study the long-term and seasonal trends of soil moisture variations, as well as estimate the temporal and spatial scales of soil moisture for different soil layers. Additional datasets of precipitation and temperature difference between land surface and air (TDSA) are analyzed to gain further insight into the changes of soil moisture. There are increasing trends for the top 10 cm, but decreasing trends for the top 50 cm of soil layers in most regions. Trends in precipitation appear to dominantly influence trends in soil moisture in both cases. Seasonal variation of soil moisture is mainly controlled by precipitation and evaporation, and in some regions can be affected by snow cover in winter. Timescales of soil moisture variation are roughly 1-3 months and increase with soil depth. Further influences of TDSA and precipitation on soil moisture in surface layers, rather than in deeper layers, cause this phenomenon. Seasonal variations of temporal scales for soil moisture are region-dependent and consistent in both layer depths. Spatial scales of soil moisture range from 200-600 km, with topography also having an affect on these. Spatial scales of soil moisture in plains are larger than in mountainous areas. In the former, the spatial scale of soil moisture follows the spatial patterns of precipitation and evaporation, whereas in the latter, the spatial scale is controlled by topography. 相似文献