新疆农业区电力负荷与天气的关系   总被引：2，自引：0，他引：2  

杨静  郝毅  陈冬梅  江波 《气象》2009,35(1):114-118

用2005--2006年新疆农业区电力负荷与气象资料,统计得出电力负荷的年、季变化与农事活动周期相符,电力负荷日变化的次高峰与日最高气温、最小相对湿度出现时间较一致.将逐月的日平均电力负荷及变化量分别与气压、气温、空气湿度、风速和降水量做相关分析,并将有无降雨日分段统计.结果表明,电力负荷与降水量、湿度和气温的变化关系较为密切.利用逐步回归方程将4种不同模式模拟的电力负荷进行了误差分析,发现要素差值模式的模拟效果较好,并对2007年5月的电力负荷进行了预测检验及误差分析,得出:在降雨日,用上一日负荷计划当日负荷的误差高达63.2%,而用要素差值模式预测电力负荷的误差为18.7%,月平均预测误差由前者的26.0%下降到13.4%.  相似文献   

RELATIONSHIPS BETWEEN PRECEDING PACIFIC SEA SURFACE TEMPERATURES AND SUBTROPICAL HIGH INDEXES OF MAIN RAINING SEASONS     

姚愚  严华生 《热带气象学报(英文版)》2009,15(1):97-101

With correlation analysis and factor analysis methods, the effects of preceding Pacific SSTs on subtropical high indexes of main raining seasons are discussed. The results of correlation analysis show that the effects of SSTs on five subtropical high indexes differ in seasons and regions. The variation of SSTs mostly affects the area and intensity indexes of the subtropical high, followed by the western ridge index, and the effect on the ridge line index is more remarkable than on the north boundary index. The results of factor analysis reveals that the first common factor of SST of each season reflected mainly the inverse relation of SSTs variation between the central and eastern part of equatorial Pacific and the western Pacific, which correlates better with the subtropical high indexes in the main raining seasons than other common factors of SST. The analysis of interdecadal variation indicated that the variation of SSTs was conducive to the emergence of the La Ni?a event before the end of 1970s, such that in the summer the subtropical high is likely to be weaker and smaller and located eastward and northward. After the 1980s, the opposite characteristics prevailed.  相似文献   

FGOALS海洋同化试验对西北太平洋夏季SST—降水关系的模拟评估     

邹立维  李东欢  周天军  吴波 《气候与环境研究》2018,23(2):139-149

评估了耦合气候系统模式FGOALS海洋同化试验对西北太平洋夏季降水和SST相关关系的模拟技巧,并对比了相应的观测海温强迫试验（AMIP）和历史气候模拟试验结果。结果显示,FGOALS海洋同化试验对亚洲季风区大部分海域夏季SST年际变化有较高的模拟技巧,但其对菲律宾以东海域模拟技巧较低。在西北太平洋夏季降水-SST相关关系方面,同化试验部分地再现了南海和菲律宾以东海域降水超前SST变化1个月和同时二者的负相关关系,优于AMIP试验但逊于自由耦合模拟试验。同化试验对SST倾向-降水相关关系的模拟技巧亦介于AMIP试验和自由耦合试验之间。观测中,西北太平洋夏季降水与环流异常受日界线附近和赤道东印度洋海洋大陆地区海温异常的遥强迫,并通过改变到达海表的净短波辐射通量影响局地SST异常,导致局地海温-降水和局地海温倾向-降水的负相关关系。在AMIP试验中,遥强迫导致的西北太平洋地区环流异常较之观测偏弱,由于缺少局地海气耦合过程,在西北太平洋多数地区表现为海温对大气的强迫作用,即SST-降水正相关关系。FGOALS同化试验和自由耦合试验考虑了局地海气耦合过程,虽然低估了遥强迫对西北太平洋地区夏季环流异常的影响,依然部分模拟出局地降水-SST负相关关系但较之观测偏弱。同时,自由耦合试验高估了西北太平洋20°N以南地区海温异常对大气环流异常的强迫,使得其对中国南海和日本岛以南海域SST-降水负相关关系的模拟稍优于同化试验。  相似文献   

多中心城市中山市职住空间关系特征     

钟国平  曹小曙 《热带地理》2016,36(4):591-599

以低密度多中心城市——中山市为例,采取政府主导的居民出行调查数据库中40445 个调查样本,应用ArcGIS 等分析工具,利用居民出行调查数据库中的个体属性与职住地点等信息,对居民职住比、通勤时间、通勤距离和通勤方向进行可视化,分析中山居民的职住空间关系格局。结果表明：职住比、通勤时间、通勤距离在空间上有一定的区域差异,但圈层结构均不明显。全市职住空间分布整体较均匀,主城区职住基本平衡;周边镇区尤其是西北组团、东部组团职住比高,而主城区较低。全市平均通勤时间和通勤距离均显著低于国内大城市和发达国家城市。主城区和外围镇区间的通勤量及其比重小,全市没有产生大规模的外围―中心“钟摆式”通勤,在通勤方向上更多表现为内―内通勤和外―外通勤。居民的职住关系空间分布特征与城市空间结构、人口结构、产业结构与产业布局、土地利用以及交通设施建设具有密切的关系,低密度多中心的城市职住平衡程度高、通勤时间和通勤距离均较短,而主城区与外围镇区通勤联系不紧密。  相似文献   

非洲地区人口与经济空间耦合研究   总被引：1，自引：0，他引：1  

蒋大亮  任航  张凌华  陈影影  张振克 《热带地理》2016,36(5):823-832

采用2003―2012 年非洲52 个国家（地区）的人口、GDP 和国土面积数据,运用地理集中度、耦合指数与区域重心等方法分析了近十年非洲地区人口与经济的耦合特征。结果表明：人口地理集中度呈现出东西高、中部低格局;经济地理集中度总体呈现出四周高、中部低的“盆地状”格局,整体上两者呈现出中度的正向相关性。根据耦合指数,非洲地区可划分为5 个类型：经济极化型、经济超前人口发展型、协调发展型、经济滞后人口发展型与经济严重滞后人口发展型。非洲地区人口重心与经济重心均位于几何重心的东南方,2003―2009 年,两者耦合关系明显;2010―2012 年,两者延伸轨迹出现一定程度的偏移,经济危机与政治危机是造成两者偏移的重要原因。  相似文献   

西北太平洋环境变化对柔鱼冬春生群体资源丰度年间变化的影响   总被引：5，自引：0，他引：5  

余为  陈新军  陈长胜  张瑜 《海洋学报(英文版)》2017,36(10):48-59

The neon flying squid Ommastrephes bartramii is an economically important species in the Northwest Pacific Ocean. The life cycle of O. bartramii is highly susceptible to climatic and oceanic factors. In this study, we have examined the impacts of climate variability and local biophysical environments on the interannual variability of the abundance of the western winter-spring cohort of O. bartramii over the period of 1995–2011. The results showed that the squid had experienced alternant positive and negative Pacific Decadal Oscillation(PDO) over the past 17 years during which five El Ni?o and eight La Ni?a events occurred. The catch per unit effort(CPUE) was positively correlated with the PDO index(PDOI) at a one-year time lag. An abnormally warm temperature during the La Ni?a years over the positive PDO phase provided favorable oceanographic conditions for the habitats of O.bartramii, whereas a lower temperature on the fishing ground during the El Ni?o years over the negative PDO phase generally corresponded to a low CPUE. The same correlation was also found between CPUE and Chl a concentration anomaly. A possible explanation was proposed that the CPUE was likely related to the climateinduced variability of the large-scale circulation in the Northwest Pacific Ocean: high squid abundance often occurred in a year with a significant northward meander of the Kuroshio Current. The Kuroshio Current advected the warmer and food-rich waters into the fishing ground, and multiple meso-scale eddies arising from current instability enhanced the food retention on the fishing ground, all of which were favorable for the life stage development of the western squid stocks. Our results help better understand the potential process that the climatic and oceanographic factors affect the abundance of the winter-spring cohort of O. bartramii in the Northwest Pacific Ocean.  相似文献   

A limit reference point to prevent recruitment overfishing of Pacific bluefin tuna     

《Marine Policy》2017

Pacific bluefin tuna (PBF) (Thunnus orientalis) is commercially important in the North Pacific Ocean. Although its stock has been relatively low for decades, international discussions on a long-term management framework, including the definition of a limit reference point (LRP), have only recently started. This paper argues that an LRP for PBF could be developed by determining a biomass level that would prevent recruitment overfishing. First, it reviews the development of LRPs for various tuna species and demonstrates that most of these limits are not necessarily based on biological information on the respective species. Then, the current management of PBF is also reviewed as background information for considering an LRP for PBF. Finally, a variety of simple analyses of the stock–recruitment relationship of PBF are conducted to find a biomass level that would prevent recruitment overfishing—i.e. an LRP below which stocks should not fall. It is concluded that, for the first time to our knowledge, defining such an LRP for a tuna species is possible (about 30 thousand tonnes or 5% of estimated unfished spawning stock biomass in our calculation). Not only is the LRP based on actual experience, but also the logic behind it would be easier for stakeholders to understand than the theoretical LRPs used elsewhere. This LRP should be useful in future in more comprehensive management framework, such as one through management strategy evaluations, in which stakeholder involvement in decision-making is crucial.  相似文献   

Adaptation of diet in a changed environment: Increased consumption of lobster krill Munida gregaria (Fabricius, 1793) by Argentine hake          下载免费PDF全文

Mauro Belleggia  Diego Giberto  Claudia Bremec 《Marine Ecology》2017,38(4)

A well‐replicated decadal‐term (2005–2014) stomach content data set was analysed in order to infer inter‐annual fluctuations in the diet of the Argentine hake, Merluccius hubbsi, an opportunistic predator in the San Jorge Gulf (SJG) ecosystem in the Southwest Atlantic. Ten research cruises were carried out each year during January from 2005 to 2014. A total of 18,461 specimens of Me. hubbsi was analysed, of which 6,777 (36.71%) contained food in their stomachs. The diet of Me. hubbsi changed markedly from 2011 onwards, with much greater consumption of the lobster krill Munida gregaria compared to the years before 2011. The frequency of occurrence (%F) of Mu. gregaria in the stomach contents of Argentine hake increased from the year 2009 onwards, most noticeably since 2011, and mostly over the southern region of the SJG. The main predators of Mu. gregaria in the SJG are two species of teleost fish (pink cusk eel, Genypterus blacodes, Argentine seabass, Acanthistius brasilianus) and three Rajidae skates (Zearaja chilensis, Psammobatis spp. and Sympterygia bonapartii), which exhibited decreased catches in the years analysed. The increased consumption of Mu. gregaria by Me. hubbsi, coupled with decreased trends in abundance of the main predators of the lobster krill during the last decade, indicate that top‐down trophic dynamic control occurs in the SJG ecosystem.  相似文献   

Host‐dependent differences in resource use associated with Anilocra spp. parasitism in two coral reef fishes,as revealed by stable carbon and nitrogen isotope analyses          下载免费PDF全文

Rachel L. Welicky  Amanda W. J. Demopoulos  Paul C. Sikkel 《Marine Ecology》2017,38(2)

The role of parasites in trophic ecology is poorly understood in marine ecosystems. Stable isotope analyses (SIA) have been widely used in studies of trophic ecology, but have rarely been applied to study the role of parasites. Considering that some parasites are associated with altered host foraging patterns, SIA can help elucidate whether parasitism influences host trophic interactions. French grunt (Haemulon flavolineatum), an abundant Caribbean coral reef fish, contributes greatly to trophic connectivity. They typically depart the reef at dusk, feed overnight in seagrass beds, and return to the reef at dawn. The large parasitic isopod Anilocra haemuli commonly infects French grunt, and infected fish are less likely to complete their diel migration, and are in poorer condition than uninfected conspecifics. Brown chromis (Chromis multilineata) are diurnally feeding planktivores and infection by Anilocra chromis does not influence host condition. To determine if Anilocra infection influences host diet and foraging locality, we conducted stable carbon and nitrogen isotope analyses on scale, muscle, heart and gill tissues of infected and uninfected French grunt and brown chromis. We determined that all French grunt had δ¹³C values representative of seagrass habitats, but infected French grunt were significantly enriched in ¹³C and ¹⁵N compared to uninfected conspecifics. This suggests that compared to uninfected conspecifics, infected French grunt forage in seagrass, but on isotopically enriched prey, and/or are in poorer condition, which can elevate δ¹³C and δ¹⁵N values. For brown chromis, infection did not significantly influence any δ¹³C and δ¹⁵N values; hence they all foraged in the same environment and on similar prey. This is the first study to use SIA to examine differences in resource use by Caribbean coral reef fishes associated with parasitism and to evaluate how closely related parasites might have host‐dependent effects on host trophic ecology.  相似文献   

F子夜均值逐日差空间异常变化与地震的关系研究   总被引：2，自引：0，他引：2  

张素琴  胡秀娟  何宇飞  杨冬梅 《地震研究》2015,38(1)

利用2010年1月1日至2014年4月30日我国地磁台网100多个台站的地磁总强度F子夜均值数据,逐一分析了F子夜均值逐日差的空间变化趋势。结果表明,在此期间有18次小区域的异常变化,其中16次异常与其后几天到半年时间内该区域发生的地震有很好的对应关系,另外两次新近的异常有待后续进一步验证。我国西北部地区地磁台站稀疏,布局不合理,限制了对新疆、青海、西藏等地震多发区震磁关系的研究,建议这些地区进一步加密台站建设,优化布局。  相似文献