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1.
根据1800-1989年(110年)的资料,分析研究了新加坡地区月平均和年平均降雨量的一些特征。主要结论是:新加坡年平均降雨量存在准2-6年和18年的周期振荡;亚洲季风以及ENSO对新加坡降雨量有明显的影响。新加坡年雨量的谷值出现在西南季风期而峰值在东北季风期。在El Nino年,新加坡降雨量多为负距平;而在反El Nino年,新加坡降雨量多为正距平。  相似文献   

2.
近海海面油类漂流扩散的研究和预测实践   总被引:4,自引:0,他引:4  
根据珠江口气象站风速与潮汐站潮位资料,对1955-1998年12次El Nino过程的珠江口季风强度与海平面变化特点进行合成分析,结果表明,El Nino发生前一年冬季,珠江口冬季平均风速较常年值大0.4m/s,El Nino发生当年,月平均风速也普遍大于常年,而月平均海平面则普遍较常年偏低,其中10与11月份负距平为6cm左右。东亚地区的季风异常对珠江口海平面异常有着重大的影响。  相似文献   

3.
1997/1998年ENSO过程与热带大气季节内振荡   总被引:3,自引:1,他引:3  
根据珠江口气象站风速与潮汐站潮位资料,对1955~1998年12次El Nino过程的珠江口季风强度与海平面变化特点进行合成分析,结果表明,El Nino发生前一年冬季,珠江口冬季平均风速较常年值大0.4 m/s,El Nino发生当年,月平均风速也普遍大于常年,而月平均海平面则普遍较常年偏低,其中10与11月份负距平为6 cm左右。东亚地区的季风异常对珠江口海平面异常有着重大的影响。  相似文献   

4.
赤道西太平洋-印度洋海温异常对亚洲夏季风的影响   总被引:8,自引:0,他引:8  
本文采用了p-σ五层原始方程模式模拟并研究了赤道西太平洋-印度洋海温距平场对亚洲夏季风的影响,计算了四种不同的海温距平试验方案。试验结果表明赤道西太平洋海温正距平使对流层下层的印度低压明显加强,副高北挺,季风槽加深,同时加强了对流层上层的反气旋环流。赤道西印度洋暖海温的模拟结果与赤道西太平洋暖海温对上述系统的影响相反,而赤道西印度洋冷海温对季风环流的影响与赤道西太平洋暧海温的影响一致。试验进一步表明赤道西太平洋-印度洋海温距平的纬向梯度方向对亚洲夏季风的影响是主要的,这一结论与实际观测结果一致。本文进一步讨论了赤道海温距平对越赤道气流、印度洋赤道东-西纬向环流和非绝热加热场的影响,结果都表明赤道西太平洋海温正距平和赤道西印度洋海温负距平的模拟特征与反El Nino年亚洲夏季环流特征类似,而赤道西印度洋海员正距平的模拟特征与El Nino年亚洲夏季坏流特征类似。  相似文献   

5.
1998年南海西南季风活动的初步分析   总被引:11,自引:3,他引:8  
利用NCEP再分析资料和OLR、SST观测数据,分析了1998年南海西南季风的建立日期、强度的多时间尺度变化特征、与海面温度的相互作用以及对广东降水的影响.得出南海西南季风建立的日期为5月17日(5月4候).1998年为弱季风年,OLR具有1个月左右的振荡周期,西南风具有半个月左右的振荡周期.孟加拉湾地区季风和105°E越赤道气流是南海季风低频变化的重要策源地.1998年南海季风弱,主要是由于初春赤道东太平洋海温正距平,并导致南海-阿拉伯海海温正距平的结果.  相似文献   

6.
热带海温变化与高原季风发展   总被引:8,自引:1,他引:8       下载免费PDF全文
利用NOAA长波辐射OLR,NCEP/NCAR再分析格点资料,探讨了热带太平洋、印度洋海温等环境场变化与高原季风发展的联系。揭示了春季孟加拉湾和南海以及西太平洋暖池附近海表增温、赤道东太平洋降温有利于高原夏季风发展。分析了高原季风强弱年同期和前期SST场、风场和OLR场演变特征。结果表明,高原季风强弱年热带环境场存在明显差异。高原夏季风发展时SSTA从春季到夏季, 孟加拉湾经南海到西太平洋SST呈正距平, 赤道中东太平洋SST负距平发展, 表现为La Ni?a特征。反之,高原夏季风减弱时SSTA在孟加拉湾和南海地区SST呈负距平,东南太平洋SST正距平发展。表现为El Ni?o特征。  相似文献   

7.
文章使用改进了的OSU全球气候模式,动态地使用厄尔尼诺年(1972年)实际下垫面温度月距平资料,对太平洋海面温度异常以及太平洋中不同关键区海面温度异常进行了敏感性试验。数值试验结果表明:El Nino实际海温时空异常,特别是关键区海面温度异常,引起了东亚季风环流的异常变化,出现了干旱的环流形势。无论赤道中太平洋或是赤道东太平洋的海面温度异常都是敏感的影响因子,对预报有一定的指示意义。  相似文献   

8.
分析了从1955~1999年45年热带、副热带太平洋地区次表层温度距平资料,在分析沿赤道距平极值曲面的深度分布后,认为它基本接近气候温跃层的深度分布.由此分析了1994~1999年该曲面上温度距平的演变发现:1997/1998年El Nino产生时,在热带西太平洋暖池次表层(160 m附近)的温度正距平,是从1994/1995年El Nino在Nino 3区的最大正距平信号传播或演变过来的,整个最大正距平信号的传播轨迹形成一似"8"字的形状.与此同时,当正的温度距平开始从暖池向东传播时,一最大温度负距平信号在Nino 3区出现,并伴随赤道最大正距平信号的东传,在其北部(5~10°N)向西传,然后又向东传最后到达Nino 3区,其传播轨迹形成一扁"0"字形状.分析表明,1997/1998年这次完整的El Nino/La Nina事件主要是在热带流系的温跃层附近形成并传播的.  相似文献   

9.
El Nio事件与番禺降水的相关性分析   总被引:9,自引:9,他引:0  
李丽云 《广东气象》2008,30(2):22-23
采用X^2检验方法,统计分析番禺地面气象站1961~2006年的逐月降水资料与El Nino现象的关系。结果表明:两类El Nino事件与番禺年降水量有密切关系,Ⅰ类El Nino事件与番禺年降水量呈强的正相关,降水增加量平均为26.63%,而Ⅱ类El Nino事件与番禺年降水量呈负相关,降水减少量平均为11.46%。从季节分布来看,两类El Nino事件对锋面降水和季风过渡季节降水影响较小,而对汛期降水影响较大。两类事件对降水影响的差异主要通过西太平洋副高脊线位置的差异表现出来:Ⅰ类El Nino事件影响年,4~6月副高脊线位置较常年偏南,7、8月偏北;Ⅱ类El Nino事件影响年,4~6月副高脊线位置较常年偏北,7、8月偏南。  相似文献   

10.
利用1955-2000年热带、副热带太平洋地区次表层温度距平资料,构造了温度距平极值深度分布曲面图,它很接近20°温度面的深度分布,因此有理由认为这一深度曲面很接近热带温跃层的深度面。在温度距平极值深度曲面上,分析了20世纪60年代后期以来所有El Nino/La Nina事件正/负海温距平信号的分布和传播“轨迹”,发现如果以暖池次表层作为起点,则一般来说,暖水或冷水先是沿赤道极值深度面向东、向上传播或运动,到达赤道东太平洋海盆边界附近后,在那里停留几个月,然后转北运动,在北纬10度左右再折向西运动到西太平洋转向南返回到暖池,即在赤道北侧形成闭合回路。温度距平运动一圈需时2-4年。如果暖(冷)水的温度距平都很强,就会在2-4年的时间上出现两次相邻的El Nino(La Nina)事件,但可能是由于大气或海洋环境条件不合适,温度距平的强度在运动过程中有时会减弱,就不能形成El Nino(La Nina)事件,但暖(冷)水运动的“轨迹”仍可辨认。由于暖、冷水绕环路的运动交替出现,El Nino(La Nina)爆发前,在赤道西太平洋出现正(负)距平信号的同时,在东太平洋北纬10度左右会有负(正)距平信号出现,并且当正(负)距平信号向东传播时,负(正)距平信号向西传播,在赤道上表现为2-4年间隔的El Nino(La Nina)交  相似文献   

11.
生态系统在全球变化中的调节作用   总被引:3,自引:2,他引:1  
讨论在全球变化的背景下,生态系统对全球变化的调节作用.首先论述陆地生态系统对全球变化的调节作用,主要包括陆地生态系统对大气成分的调节以及对全球气候的调节;其次,论述水生生态系统对全球变化的调节作用,主要包括淡水生态系统对全球变化的调节作用以及海洋生态系统对全球变化的调节作用;最后,论述湿地生态系统对全球变化的调节作用,主要包括湿地生态系统对生物多样性保护的功能,湿地对全球变化的元素调节作用以及湿地对气候和水文的调节.    相似文献   

12.
我国主要水稻雄性不育系的光温特性研究   总被引:3,自引:1,他引:3  
根据10个水稻雄性不育系的生育期及期间的温度和日长资料,研究了它们的光、温生态特性。用通径分析方法,分析了决定各不育系生育期变化的决策变量结果表明:晚籼及晚粳类型不育系的感光性强,中籼类型不育系的感光性弱到中等,早籼类型不育系的感光性一般都弱。10个雄性不育系中感温性弱的只占少数,感温性属弱到中强的品种占多数。除HS-3和SE21S的生育期决策变量为日长外,其他各不育系的决策变量均为温度。  相似文献   

13.
The planetary boundaries (PBs) framework proposes global quantitative precautionary limits for human perturbation of nine critical Earth system processes. Together they define a global safe operating space for human development. Translating the global limits to the national level increases their policy relevance. Such translation essentially divides up the global safe operating space. What is considered fair distribution is a political decision and there is no globally agreed principle that can be applied. Here, we analyse the distributional consequences of alternative perspectives on distributive fairness. We scale the global limits of selected PBs to resource budgets for the EU, US, China and India, using three allocation approaches from the climate change literature. Furthermore, we compare the allocated budgets to 2010 environmental footprints of the four economies, to assess their performance with respect to the selected PBs. The allocation approaches are based on (1) current shares of global environmental pressure (‘grandfathering’); (2) ‘equal per capita’ shares, and (3) ‘ability to pay’ to reduce environmental pressure. The results show that the four economies are not living within the global safe operating space. Their 2010 environmental footprints are larger than the allocated budgets for all approaches and parameterisations analysed for the PBs for climate change and biogeochemical flows, and, except for India, also for the PB for biosphere integrity. Grandfathering was found to be most favourable for the EU and US for all PBs, and ability to pay as least favourable. For climate change and biogeochemical flows, ability to pay even resulted in negative resource budgets for the two economies. In contrast, for China and India, equal per capita allocation and ability to pay were most favourable. Results were sensitive to the parameterisation. Accounting for future population growth in the equal per capita approach benefits India, with lower budgets for the EU, US and China, while accounting for future economic growth in ability to pay benefits the EU and US, with lower budgets for China and India. Our results underline the need for all four economies to act, while hinting at diverging preferences for specific allocation approaches. The methodology and results may help countries to define policy targets in line with global ambitions, such as those defined by the Sustainable Development Goals (SDGs), accounting for differences in countries’ circumstances and capacities. Further attention is required for PB-specific allocation approaches and integration of biophysical and socioeconomic considerations in the allocation.  相似文献   

14.
Analyses of long-term (1991–2010) intercomparison data quantify the consistency of winter precipitation observations by six identical Tretyakov gauges at the Valdai research station in Russia. Relative to the standard Tretyakov gauge, the mean catch ratios are 97 to 106% for dry snow, 94 to 104% for wet snow, 87 to 109% for blowing snow, 96 to 103% for mixed precipitation, and 98 to 101% for winter rain. The differences between the highest and lowest mean catches are about 10 to 11% for snow, 7% for mixed precipitation, and 3% for rain. On average, this difference is about 0.2?mm over the 12-hour observation period. The catch difference for blowing snow is much higher, up to 22%, or an average of 0.6?mm per observation. Comparisons of 12-hour observations show better consistency in gauge performance for low snowfall events and a large variation in gauge catch for high snowfall events. The differences in 12-hour snow catches are mostly less than 2?mm among the six gauges. The differences in the 12-hour observations are less than 1% for rain and 4% for mixed precipitation. Close linear relationships exist between the 12-hour gauge observations for all precipitation types. The maximum differences in gauge snow catches increase very weakly with wind speed, and higher differences are associated with warmer temperatures, from ?5°C to 0°C. There is, however, no significant relationship between the maximum catch difference and the mean wind speed or temperature over the 12-hour period.  相似文献   

15.
A conceptual framework for climate change assessments of international market systems that involve long-term investments is proposed. The framework is a hybrid of dynamic and static modeling. Dynamic modeling is used for those system components for which temporally continuous modeling is possible, while fixed time slices are used for other system components where it can be assumed that underlying assumptions are held constant within the time slices but allowed to vary between slices. An important component of the framework is the assessment of the “metauncertainty” arising from the structural uncertainties of a linked sequence of climate, production, trade and decision-making models. The impetus for proposing the framework is the paucity of industry-wide assessments for market systems with multiple production regions and long-term capital investments that are vulnerable to climate variations and change, especially climate extremes. The proposed framework is pragmatic, eschewing the ideal for the tractable. Even so, numerous implementation challenges are expected, which are illustrated using an example industry. The conceptual framework is offered as a starting point for further discussions of strategies and approaches for climate change impact, vulnerability and adaptation assessments for international market systems.  相似文献   

16.
In this paper we present the current capabilities for numerical weather prediction of precipitation over China using a suite of ten multimodels and our superensemble based forecasts. Our suite of models includes the operational suite selected by NCARs TIGGE archives for the THORPEX Program. These are: ECMWF, UKMO, JMA, NCEP, CMA, CMC, BOM, MF, KMA and the CPTEC models. The superensemble strategy includes a training and a forecasts phase, for these the periods chosen for this study include the months February through September for the years 2007 and 2008. This paper addresses precipitation forecasts for the medium range i.e. Days 1 to 3 and extending out to Day 10 of forecasts using this suite of global models. For training and forecasts validations we have made use of an advanced TRMM satellite based rainfall product. We make use of standard metrics for forecast validations that include the RMS errors, spatial correlations and the equitable threat scores. The results of skill forecasts of precipitation clearly demonstrate that it is possible to obtain higher skills for precipitation forecasts for Days 1 through 3 of forecasts from the use of the multimodel superensemble as compared to the best model of this suite. Between Days 4 to 10 it is possible to have very high skills from the multimodel superensemble for the RMS error of precipitation. Those skills are shown for a global belt and especially over China. Phenomenologically this product was also found very useful for precipitation forecasts for the Onset of the South China Sea monsoon, the life cycle of the mei-yu rains and post typhoon landfall heavy rains and flood events. The higher skills of the multimodel superensemble make it a very useful product for such real time events.  相似文献   

17.
热带地区大气环流的异常,与我国南方春季旱涝关系十分密切。本文通过对热带大气环流、低纬度波谱特征及物理量特征等的分析,初步揭示了福建春季旱涝与热带、副热带大气环流异常的内在联系。   相似文献   

18.
从’98特大洪水中看改进的HLAFS数值降水预报的性能   总被引:2,自引:1,他引:2  
文章对1998年大洪水期间改进的HLAFS[1]的降雨预报产品进行检验.结果表明, 改进的HLAFS对松嫩流域的暴雨预报较好, 中到大雨则是长江中下游地区预报较好, 而三峡库区相对较差; 对于主要降雨过程降雨区的强度预报往往比实况弱, 且其落区约有半数较实况偏北, 但其轴向一般与实况一致; 改进的HLAFS对小雨预报比原HLAFS好, 对中雨和暴雨预报也有不同程度的改进; 整体预报面积偏大和大雨以上降水预报准确率低仍是HLAFS有待改进的问题.对三峡库区面降水量预报, 半数左右的预报较好; 对大量级降水预报往往偏弱, 而小量级则相反  相似文献   

19.
Independent test results of four different weather forecast models [climatological, persistence, analogue, and regional mesoscale weather simulation (MM5) model] have been compared for four past winters (winter 2003–2004 to winter 2006–2007) for qualitative weather (snow day/no snow day) and quantitative categorical snowfall prediction at six different areas in northwest Himalaya (NW-Himalaya) in India. Weather forecast guidance provided by the MM5 model at 10 km resolution was taken for the study. Test results of MM5 and the analogue model were compared for a limited number of days (with irregular gaps) due to lack of availability of MM5 weather forecast guidance for complete winter periods. Forecasts based on the persistence, climatological, and analogue models were compared for day 1 predictions only. Performance of the analogue model for qualitative weather prediction was found to be comparable to that of the MM5 model for day 1 prediction. However, for day 2 and day 3, performance of the MM5 model was found to be marginally better than that of the analogue model. Marginal difference in overall accuracy of the analogue and MM5 models was found for quantitative categorical snowfall prediction for day 3. The quantitative categorical snowfall forecast error of the MM5 model was found to be greater than that for the analogue model for all three days. Comparative study of the performance of the climatological, persistence, and analogue models showed that the analogue model performs better than the persistence and climatological models for day 1 predictions. The results of this study suggest that the analogue model shows some capability for weather prediction and, along with the MM5 model, could be a useful tool for weather forecasters. Comparative study of the performance of the MM5 model at high resolution (about 2–3 km) and the analogue model for complete winter period may provide some interesting and fruitful results.  相似文献   

20.
Climate change is causing important shifts in the suitability of regions for wine production. Fine scale mapping of these shifts helps us to understand the evolution of vineyard climates, and to find solutions through viticultural adaptation. The aim of this study is to identify and map the structural and spatial shifts that occurred in the climatic suitability for wine production of the Cotnari wine growing region (Romania) between 1961 and 2013. Discontinuities in trends of temperature were identified, and the averages and trends of 13 climatic parameters for the 1961 to 1980 and 1981 to 2013 time periods were analysed. Using the averages of these climatic parameters, climate suitability for wine production was calculated at a resolution of 30 m and mapped for each time period, and the changes analysed. The results indicate shifts in the area’s historic climatic profile, due to an increase of heliothermal resources and precipitation constancy. The area’s climate suitability for wine production was modified by the loss of climate suitability for white table wines, sparkling wines and wine for distillates; shifts in suitability to higher altitudes by about 67 m, and a 48.6% decrease in the area suitable for quality white wines; and the occurrence of suitable climates for red wines at lower altitudes. The study showed that climate suitability for wine production has a multi-level spatial structure, with classes requiring a cooler climate being located at a higher altitude than those requiring a warmer climate. Climate change has therefore resulted in the shift of climate suitability classes for wine production to higher altitudes.  相似文献   

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