共查询到19条相似文献，搜索用时 203 毫秒
1.
青藏高原作为耸入对流层中层的“巨大热岛”,其产生的热力强迫对东亚以及全球的天气气候起着举足轻重的作用。因此,关于夏季高原热源对下游降水影响及其机理的研究有助于加深对青藏高原影响下游天气气候的认识,提高青藏高原及下游降水的预报水平。本文针对青藏高原夏季热源的时空分布及演变特征、青藏高原热源在不同时空尺度上对下游降水的影响规律及物理机制,总结了已有的相关研究进展,指出了存在的主要问题,并展望了未来不同时空尺度上青藏高原热源对下游降水影响的研究方向,提出了值得进一步加强研究的重点与难点问题。 相似文献
2.
《气象科学进展》2016,(3)
时空均一的气候资料是气象科研、业务和服务的基础。介绍了气候资料均一性的基本概念、涉及范围、主要原因以及解决非均一性问题的意义。在此基础上,阐述了国际上气候资料均一性研究的动态和技术发展历程,指出以高时空分辨率的均一化为标志的第二代气象数据产品研发趋势为气候资料均一性研究带来良好的发展机遇和严峻的挑战;结合对我国地面、高空和辐射三类气候资料均一性概况和相关研究现状的总结,分析了我国在相关领域研究的深度和广度上存在的差距和不足,以及当前需要解决的关键科学和技术问题。最后,就如何正确认识气候资料的均一性,如何深化我国气候资料均一性研究,加强气候数据产品研发,实现我国数据产品研发技术和管理水平上一个新台阶等提出了建议。 相似文献
3.
在本文中,首先提出了用近似的解析表达式定量描述气候要素场的一般问题。作者认为:利用正交函数的线性组合作为近似表达式是具有许多优点的。提出了一个衡量准确度的计算公式,计算了两个实例,求出线性组合中各项的系数、用线性组合表示的定量描述方程、原始资料数据相对于描述方程的相关指数、标准误差和方差比,并且从各项系数对相关指数的贡献中比较了各项的相对重要性。 相似文献
4.
利用BP-CCA方法并结合当前国际先进气候预测模式结果,探讨了如何建立对西南夏季降水具有较高预测技巧的统计降尺度模型及其可预报性来源。结果表明,将热带区域海表温度作为预测因子的降尺度模型的预测能力优于亚洲区域和热带区域500 h Pa位势高度作为预测因子的模型。对模型可预报性来源的分析表明,热带区域海表温度作为预测因子的降尺度模型的预测能力年与年之间的差异主要受热带海表温度EOF第二模态的影响。该模态表现为在热带东南印度洋及西太平洋区域有正载荷值,而在热带中东太平洋区域有负载荷中心,其与影响西南夏季降水的菲律宾和海洋大陆西部对流有较好的相关,并且ECMWF和NCEP业务气候预测模式对其有较好的预测能力。 相似文献
5.
潘建华 《高原山地气象研究》2005,25(1)
本文根据1971～2000年(简称新30年)四川省资料,分析了全省冰雹的时空和季节分布、年际变化、冰雹强度及持续、降落时间、致灾情况等各种特点,对最近30年四川省冰雹的天气气候状况做了较为详细的描述. 相似文献
6.
农业气候调和指数的研究 《气象与环境学报》1992,9(1):21-24
一、农业气候调和指数的求算气候调和与否是建立在一定的农业气候特点基础上的。它与各种气候条件的时空分布、配合形式有关。各种气候条件的时空分布,不同气候要素之间的相互配合与作物生育和农事活动相适应,就说明气候调和,否则反之。本文提出的气候调和指数即为评价气候调和程度的温度、降水配合的综合指标。 相似文献
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8.
提出一种气候场的主分量逐步回归预测模型,该模型将气候场的预测变成对该场主分量的预测。提取对气候场变化有重要影响的500 hPa高度、太平洋及印度洋海温和全球海平面气压等含不同区域不同季节的因子场的前若干个含高信息量的优质主分量因子。通过相关筛选和双重检验逐步回归,建立气候场的主分量的预测方程,由此就建立气候场与多个因子场之间的联系,但是模型却仍然保持着两个场相关的特点。根据气候场的特征向量的近似不变性,将其与主分量配合进行反算,从而得到气候场的预测。以广东汛期降水预测作为试验例子,计算了它的主分量,分析了它的时空分布特征及分类,对2003—2005年的分布作预测并与实测分布作比较及进行误差检测,发现预测效能显著。有关预测的年限、区域范围、要素和因子的物理背景等问题有待进一步研究。 相似文献
9.
新30年四川冰雹特征分析 总被引：2，自引：0，他引：2
本文根据1971-2000年(简称新30年)四川省资料，分析了全省冰雹的时空和季节分布、年际变化、冰雹强度及持续、降落时间、致灾情况等各种特点，对最近30年四川省冰雹的天气气候状况做了较为详细的描述。 相似文献
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11.
A Loading Correlation Model for Climatic Classification in Terms of Synoptic Climatology 总被引：1，自引：0，他引：1
C. S. Yao 《Theoretical and Applied Climatology》1998,61(1-2):113-120
Summary By using the orthogonal transformations between principal components and original variates, a loading correlation model is
proposed as a technique for climatic classification derived from synoptic climatology. The criterion for a loading correlation
model for a climate region is that all the first loading correlations are positive and significant. The climate region includes
all the stations chosen in the model.
The first positive significant loading correlations and other significant ones in the model, fitted to the climate region,
can be identified as the average circulation type and the average circulation features, respectively, by using the decomposition
of the original variates. Thus, the regional climate can be described in terms of synoptic climatology.
The mathematical structure of the loading correlation model is based on empirical orthogonal functions with two additional
parameters, the standard deviation of the principal components and the original variates.
Received July 8, 1996 Revised November 10, 1997 相似文献
12.
M. R. Jury 《Theoretical and Applied Climatology》1997,57(3-4):155-163
Summary Principal components analysis of satellite outgoing longwave radiation (OLR) anomalies over southern Africa forms the basis of this work. OLR anomalies, which are closely correlated with rainfall anomalies and vegetation cover, are formulated for early and late summer, the season when convective clouds develop over southern Africa. The first four principal component modes account for 82 to 85% of the total inter-annual convective variability in the period 1975–1994. The dominant terrestrial modes take the form of truncated dipoles (36%). NW-SE oriented loading patterns contributed by cloud bands and poleward tropical outflows, form the second most important climate mode (25%). Lower order modes are dominated by monsoon effects (12%) and isolated cells (10%). The dominant modes of convective variability appear related to the phase of the Southern Oscillation and its regional signals. The principal component results indicate that attention should be given to understanding mechanisms underlying dipole circulation systems.With 5 Figures 相似文献
13.
Sources of knowledge and ignorance in climate research 总被引：1，自引：1，他引：0
Ignorance is an inevitable component of climate change research, and yet it has not been specifically catered for in standard
uncertainty guidance documents for climate assessments. Reports of ignorance in understanding require context to explain how
such ignorance does and does not affect understanding more generally. The focus of this article is on dynamical sources of
ignorance in regional climate change projections. A key source of ignorance in the projections is the resolution-limited treatment
of dynamical instabilities in the ocean component of coupled climate models. A consequence of this limitation is that it is
very difficult to quantify uncertainty in regional projections of climate variables that depend critically upon the details
of the atmospheric flow. The standard methods for quantifying or reducing uncertainty in regional projections are predicated
on the models capturing and representing the key dynamical instabilities, which is doubtful for present coupled models. This
limitation does not apply to all regional projections, nor does it apply to the fundamental findings of greenhouse climate
change. Much of what is known is not highly flow-dependent and follows from well grounded radiative physics and thermodynamic
principles. The growing field of applications of regional climate projections would benefit from a more critical appraisal
of ignorance in these projections. 相似文献
14.
Amazonian climate: results and future research 总被引：1，自引：0，他引：1
J. H. C. Gash C. Huntingford J. A. Marengo R. A. Betts P. M. Cox G. Fisch R. Fu A. W. Gandu P. P. Harris L. A. T. Machado C. von Randow M. A. Silva Dias 《Theoretical and Applied Climatology》2004,78(1-3):187-193
Summary Some of the results from the climate component of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA), which are presented in this Special Issue are summarised. Recent advances in Amazonian climate modelling are also discussed. There is a range of papers which fall into three groups: surface fluxes and boundary layer growth; convection, clouds and rainfall; and climate modelling. The new insight given by this work is discussed and an argument is made for future research to employ a wider approach to Amazonian climate modelling. 相似文献
15.
A new way of quantifying GCM water vapour feedback 总被引：1，自引：0，他引：1
William Ingram 《Climate Dynamics》2013,40(3-4):913-924
The water vapour feedback probably makes the largest contribution to climate sensitivity, and the second-largest contribution to its uncertainty, in the sense of disagreement between General Circulation Models (GCMs, the most physically detailed models of climate we have). Yet there has been no quantification of it which allows these differences to be attributed physically with the aim of constraining the true value. This paper develops a new breakdown of the non-cloud LW (longwave) response to climate change, which avoids the problems of the conventional breakdown, and applies it to a set of 4 GCMs. The basic physical differences are that temperature is used as the vertical coordinate, and relative humidity as the humidity variable. In this framework the different GCMs’ feedbacks look more alike, consistent with our understanding that their water vapour responses are physically very similar. Also, in the global mean all the feedback components have the same sign, allowing us to conveniently attribute the overall response fractionally (e.g. about 60% from the “partly-Simpsonian” component). The systematic cancellation between different feedback components in the conventional breakdown is lost, so now a difference in a feedback component actually contributes to a difference in climate sensitivity, and the differences between these GCMs in the non-cloud LW part of this can be traced to differences in formulation, mean climate and climate change response. Physical effects such as those due to variations in the formulation of LW radiative transfer become visible. Differences in the distribution of warming no longer dominate comparison of GCMs. The largest component depends locally only on the GCM’s mean climate, so it can in principle be calculated for the real world and validated. However, components dependent on the climate change response probably account for most of the variation between GCMs. The effect of simply changing the humidity variable in the conventional breakdown is also examined. It gives some of this improvement—the loss of the cancellations that leave the conventional breakdown of no use to understand differences between GCMs’ climate sensitivities—but not the link to mean climate. 相似文献
16.
Jennifer C. Whitman Jiaying Zhao Kevin H. Roberts Rebecca M. Todd 《Climatic change》2018,147(3-4):383-394
Despite the scientific consensus, there is widespread public controversy about climate change. Previous explanations focused on interpretations hampered by political bias or insufficient knowledge of climate facts. We propose that public views of climate change may also be related to an attentional bias at a more basic level of cognitive processing. We hypothesized that selective visual attention towards or away from climate-related information would be associated with climate concern. To test prioritization of climate-related stimuli under conditions of limited attention, we asked participants to identify climate-related and neutral words within a rapid stream of stimuli. Undergraduate students attended to climate-related words more readily than neutral words. This attentional prioritization correlated with self-rated climate concern. We then examined this relationship in a more diverse community sample. Principal component analysis of survey data in the community sample revealed a component indexing a relationship between climate concern and political orientation. That component was correlated with the degree of selective inattention to climate-related words. Our findings suggest that climate-related communications may be most effective if tailored in a manner accounting for how attentional priorities differ between audiences—particularly those with different political orientations. 相似文献
17.
Statistical properties of the temperature, relative humidity, and net solar radiation in the Blue Nile-eastern Sudan region 总被引：1，自引：1，他引：0
Chong-Yu Xu Qiang Zhang M. El Hag El Tahir Zengxin Zhang 《Theoretical and Applied Climatology》2010,101(3-4):397-409
This paper presents the results of the first stage of an ongoing project of evaluating the spatial and temporal variability of soil water as fundamental factors for vegetation regeneration in the arid ecosystems in the Blue Nile-eastern Sudan. The specific aim of the present study is to understand the temporal and spatial variations of the major climate variables in the region and discuss its relevance to regional climate variability and changes. In this case, we systematically analyze the major climate variables (maximum and minimum air temperature, relative humidity, and net solar radiation). To evaluate the different characteristics of the climate variables, Mann–Kendall method, two-phase regression scheme, and wavelet transform technique are used; each method has its own strength and weakness, and the results of the three methods complement each other. The results show that the annual and seasonal maximum temperatures are increasing significantly. The annual minimum temperature and minimum temperature in dry seasons are decreasing. The minimum temperature in rainy season is increasing with a smaller rate as compared with the increase of maximum temperature in the season. The difference between maximum and minimum temperature is increasing in all the seasons. Net solar radiation in the region shows a significant increasing trend in all seasons, which corresponds well with the changes of maximum temperature. Besides, significant decreasing trends can be identified for relative humidity in all the seasons. 相似文献
18.
Coupled ocean-atmosphere models with flux correction 总被引：11，自引：3，他引：11
A method is proposed for removing the drift of coupled atmosphere-ocean models, which in the past has often hindered the application of coupled models in climate response and sensitivity experiments. The ocean-atmosphere flux fields exhibit inconsistencies when evaluated separately for the individual sub-systems in independent, uncoupled mode equilibrium climate computations. In order to balance these inconsistencies a constant ocean-atmosphere flux correction field is introduced in the boundary conditions coupling the two sub-systems together. The method ensures that the coupled model operates at the reference climate state for which the individual model subsystems were designed without affecting the dynamical response of the coupled system in climate variability experiments. The method is illustrated for a simple two component box model and an ocean general circulation model coupled to a two layer diagnostic atmospheric model. 相似文献