首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A discussion of the mass transport of the Hadley circulation is presented, with regard to its longitudinal structure. Data from the NCEP/NCAR reanalysis data set for the period 1948–2005 is examined, focusing on the solsticial seasons of June–August and December–February. Quantitative estimates have been extracted from the data to observe connections between the zonal mean of the upper tropospheric north/south mass transports and their relationship to the driving factor of tropical precipitation (implying latent heat release) and subsidence in the subtropical high pressure belts. The longitudinal structure of this flow is then examined with regard to these three main variables. The poleward upper tropospheric transport has four (JJA) or three (DJF) main branches, which link regions of major precipitation with corresponding regions of large subsidence, and one (June, July, August) or two (December, January, February) reverse branches. This structure has remained stable over the past sixty years. Although the total upper tropospheric transport in each season is less than the total sinking transport in the target subtropical high pressure belt, this does not apply to the individual branches, the balance being made up by the upper tropospheric reverse transports. An analysis of correlations between all of these various components shows, however, that the complete picture is more complex, with some precipitation regions being linked to subsidence regions outside their own branch.  相似文献   

2.
作为地球系统的主要能量来源,进入地磁系统的太阳风能量通量(E_(in))一直难以估算。因此,E_(in)对气候的影响也没有得到广泛的研究。基于三维磁流体动力模拟估算的E_(in),本文指出,太阳风能量通量不仅存在准11年周期的年代际变率,同时还存在2-4年周期的年际变率。与以往主要关注太阳活动在年代际尺度上的气候效应的研究不同,本文揭示出太阳风能量通量与次年ENSO年际变率存在显著的联系。  相似文献   

3.
利用1979—2010年间的JRA-25再分析资料、太阳常数观测资料,重现了1979—2010年间的各能量的时间序列,并对整层大气、对流层大气和平流层大气这3个大气层能量的演变规律及其与太阳活动的关系进行了分析。结果表明:(1)整层大气的总能量和对流层大气的总能量,两者都存在一个显著的3.7 a的周期;而平流层大气的总能量具有一个显著的11~22 a的振荡周期;平流层大气对太阳活动的响应,与对流层大气对太阳活动的响应有所不同:平流层大气的总能量的变化略落后于太阳常数的变化,但是整层大气和对流层大气的总能量的变化均是超前于太阳常数的变化。(2)整层大气、对流层大气和平流层大气这3个层次的总能量和太阳常数分别具有显著的4~11 a的共振周期、5.5~7.3 a的共振周期和3.7~11 a的共振周期。  相似文献   

4.
It is clear that developing countries will have to be part of the global mitigation effort to avoid ‘dangerous climate change’, and, indeed, many of them are already undertaking significant actions on multiple fronts to help address this problem, even if they have not yet taken on legally binding commitment under the United Nations Framework Convention on Climate Change (UNFCCC). Since the deployment of GHG-mitigating technologies is already a significant part of this effort and likely to be even more so in the future, drawing lessons from existing programmes can help accelerate and enhance the effectiveness of this deployment process. Accordingly, this article aims to examine the deployment of wind and solar power in India, paying specific attention to the role of public policy in incentivizing and facilitating this deployment, how these policies have evolved over time, what has shaped this evolution, and what the learning has been over this period. Through this analysis, the intention is to draw out key lessons from India's experience with deployment policies and programmes in these two sectors and highlight the issues that will need to be given particular consideration in the design of future domestic policies and international cooperation programmes to enhance the move towards climate-compatible development in India. Many of these lessons should also be relevant for other developing countries that are attempting to balance their climate and developmental priorities through the deployment of renewable energy technologies.  相似文献   

5.
广西风能资源评价工作探讨   总被引:7,自引:1,他引:7  
甘一忠 《广西气象》2005,26(4):55-56
分析广西风能资源评价工作取得的主要成绩和存在问题,为进一步做好广西风能资源评价工作,提出一些探讨性思路。  相似文献   

6.
在再生资源中,风能的作用越来越受到人们的重视。目前,利用风能发电的国家约50多个,我国风力资源居世界第一,但风能发电发展相对落后,如何合理利用风能这一再生能源,在煤炭、石油资源越来越匮乏的今天,显得越来越重要了,根据泰来县所处的特殊地理位置,就泰来县风能资源做了进一步调查,调查报告如下。泰来县地处嫩江平原西南部与大兴安岭东麓相接,受东亚西风带影响区,使这一地区出现风速大,气温高,干燥的气候特点,是同一纬度区域中风能资源丰富区,有利于风能的开发。1泰来县风速的分布状况据统计泰来县近30a(1975 ̄2005年)风速,结果表明:泰来…  相似文献   

7.
分析广西风能资源评价工作取得的主要成绩和存在问题,为进一步做好广西风能资源评价工作,提出一些探讨性思路。  相似文献   

8.
A simple numerical model is constructed to investigate the time-history of the dissipation of the valley wind system. The local wind system is considered as a thermally induced circulation. The Coriolis force, effect of slope of the valley floor and advection of heat and momentum are not considered in this study. The non-dimensional forms of the heat-diffusion and momentum equations along the direction of the valley axis are numerically integrated with a set of specified initial conditions, boundary conditions and assumed heat sources (and sinks). Three cases are presented in this report. The numerical solutions are in good agreement with the observed features of the dissipation of the valley wind provided that a relative heat source at ridge-line level and a relative heat sink at the ground are hypothesized.The major part of the research presented in this paper was done while the author was at the Department of Meteorology and Oceanography, New York University.  相似文献   

9.
对乐山市2001年8月7日出现的风雹天气,利用711数字化雷达资料进行雷达回波分析,为短时预报和服务提供依据,发挥雷达在短时预报服务中的效益,为使用数字化雷达资料提供一些帮助.  相似文献   

10.
对乐山市2001年8月7日出现的风雹天气,利用7ll数字化雷达资料进行雷达回波分析,为短时预报和服务提供依据,发挥雷达在短时预报服务中的效益,为使用数字化雷达资料提供一些帮助。  相似文献   

11.
本文利用全省各地的年、月平均风速直接计算实有风能,平均有效风速的年、日分布特征,不同等级风速频率分布特征,最大风速的推定及其结果,风能密度的计算,将全省风能资源按其优劣程度划分为3个区域等级进行评价。  相似文献   

12.
基于焉耆国家基准气候站1993-2012年逐月太阳总辐射和日照观测资料以及和静、巴音布鲁克1961-2012年月日照百分率资料,建立回归分析方程,推算和静县山区及平原地区逐月的太阳总辐射,对比分析了和静县山区及平原地区太阳总辐射变化特征,从太阳能资源丰富度、资源稳定性及可利用价值等方面对和静县太阳能资源状况进行评估。结果表明:1961-2012年和静县平原及山区太阳总辐射均呈减少的趋势,平原地区7月太阳总辐射最多,山区5月最多,最少值均出现在1月;平原地区属太阳能资源很丰富区,山区为丰富区;平原地区及山区太阳能资源均较稳定;平原地区年平均可利用太阳辐射的天数为286 d,山区为267 d;平原和山区一天中上午和中午是最有利的利用时段。  相似文献   

13.
 The period and amplitude of the tropical intraseasonal oscillation in the Hadley Centre Global Climate Model have been examined by applying time filtering and spectral analysis techniques to time series of daily velocity potential. Results from an AMIP integration of the model, forced with observed sea surface temperatures for the decade 1979-88 show that the model has a reasonable degree of skill in simulating the main features of the oscillation, although the signal in the model is rather noisy compared to NWP analyses. The model also shows interannual variability of the oscillation similar in magnitude to that in the analyses. The impact on the oscillation of including a parametrization of momentum transport by cumulus convection is assessed. This parametrization significantly improves the mean circulation of the model, reducing systematic errors particularly in the tropics. However, the strength and coherence of the tropical intraseasonal oscillation are significantly reduced by this parametrization. It is speculated that this may be related to a reduction in westerly flow in the tropical central and east Pacific and a reduction in the strength of the SPCZ in DJF. Received: 17 July 1996/Accepted: 30 January 1997  相似文献   

14.
The paper describes various aspects of the wind regime in coastal areas as obtained from several experimental programs along the Baltic coast of Sweden. The studies include the change with distance inland of mean wind structure as well as the turbulence structure in various conditions. It is found that wind spectra are usually well described by local similarity in its high frequency part, even in complex terrain. The low frequency parts of the spectra show clear spectral lag effects. The effects of a small slope, ca 5 m height change over 300 m travel distance, is clearly seen in some spectra, and it is shown that current flow over a hill theory can be used to account for it. The change of mean wind speed throughout the entire boundary layer as the wind passes a low but wooded island (Gotland), ca 30 km wide, has been studied in a series of relatively strong wind, near neutral cases. Some unexpected features are found; in particular the wind speed decreases more rapidly with distance inland than predicted by current numerical models. Two cases with a low level jet are discussed in some detail. Arguments are presented for the phenomenon to be caused by frictional decoupling at the Latvian coast, about 200 km upwind — the jet being thus an analogy in space to the classical Blackadar nocturnal jet frequently observed in continental areas.  相似文献   

15.
16.
Of several non-conventional energy sources, wind is probably the most suitable and cost effective for generating electricity and for water pumping. It is essential to establish the available wind energy (AWE) for any given region so as to assess the relative potential at different sites. In the present paper, an attempt is made to study the AWE over south India, an area that is peninsular in nature. A climatological estimate is made for January. April, July and October which are typical of winter, pre-monsoon, monsoon and post-monsoon seasons, respectively. The energy pattern factor is also estimated. The spatial and seasonal variation of AWE is studied.  相似文献   

17.
F.M. Boyce 《大气与海洋》2013,51(3):195-206
Abstract

The paper discusses the possibility of extracting electrical energy from the thermal energy stored in stratified lakes. Three situations are examined, an open lake or pond acting as a solar collector, a combination of waste heat and solar energy, and selective withdrawal of warm and cold streams from a stratified hydroelectric reservoir. Approximate calculations of the energy returns are made for typical conditions. The returns are limited by environmental factors as well as a short operating season. By using the deep stratified Great Lakes (Superior, Huron, Michigan and Ontario) as solar collectors, a few thousand megawatts of electrical power could be produced in the Great Lakes Basin during the summer months. This power could be produced on a year‐round basis by a single large nuclear generating station.  相似文献   

18.
利用海陆风和山谷风的机制和特点来分析万宁温度、降水分布及变化原因。  相似文献   

19.
Public policy has played an important role in the development of wind energy technology. However, compared to the rich literature on the supporting mechanisms for frontrunner countries, little research has focused on the latecomers, especially regarding the catch-up and take-over process. The key policy initiatives that would enable latecomers to fulfil their technology leapfrogging goals are also unclear. Using the empirical setting of the Chinese wind energy market, four phases of technology development based on technological capacity and market development status are identified. The logic of the policy initiatives selected for each phase is then illustrated in light of the prevailing sectoral goals and macro policy framework. The findings confirm the interactive relationship between the various factors and also illustrate that technological capacity is the fundamental factor for achieving sustainable leapfrogging.  相似文献   

20.
Theoretical and Applied Climatology - In this paper, we analyzed the influence of future climate change on wind energy potential in the Republic of Serbia. We used climate projections from two...  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号