长江口外及其邻近海域含沙量时空变化特征分析   总被引：2，自引：0，他引：2  

孔亚珍  丁平兴  贺松林  何超  肖文军 《海洋科学进展》2006,24(4):446-454

根据2005年7月和11月在长江口外进行的大范围水文、泥沙调查资料,分析了长江口外及其邻近海域含沙量的时空变化特征。结果表明:研究区域内含沙量近岸高,外海低;不论夏、秋季与大、小潮,杭州湾含沙量最高,其次是长江口外,临近123°E站含沙量比杭州湾、长江口处含沙量低1~2个数量级;所测量区域内含沙量呈现出显著和复杂的潮周期、大小潮和夏秋季变化特征。对长江口外及邻近海域含沙量时空变化特征的原因进行了初步分析。  相似文献   

前期春季西北太平洋潜热通量与中国南方秋季降水的联系及其可能的物理机制          下载免费PDF全文

刘嘉慧敏  张文君  何金海  祁莉 《Acta Meteorologica Sinica》2015,73(2):305-318

利用中国科学院海洋研究所提供的印度洋—太平洋海洋热通量资料,研究了1989—2010年中国南方地区秋季降水与前期春季西北太平洋潜热通量年际变化的联系,并讨论了其可能的物理机制。结果表明,前期春季4月西北太平洋(15°—30°N,150°—170°E)潜热通量与中国南方秋季降水有显著的正相关,当前期关键区潜热通量偏高(低)时,则中国南方秋季降水偏多(少)。分析发现前期关键区潜热通量强弱主要由西北太平洋上空气旋性风切变造成,当前期4月关键区潜热通量偏大时,该关键区正处于西北太平洋上空气旋性风切变北侧大风区中,而在其南侧的赤道强西风使得日界线附近出现海温偏高。随后,次表层高海温伴随开尔文波东传,相应地其北侧的低海温伴随罗斯贝波西传,于秋季西传至热带西太平洋地区,并激发出菲律宾反气旋,从而有利于热带洋面暖湿水汽向中国南方输送,使得南方地区降水偏多,反之亦然。  相似文献   

长白山针阔混交林秋季净生态系统水气交换量     

温学发  于贵瑞  孙晓敏  Li Qingkang  REN Chuanyou  HAN Shijie 《地理学报(英文版)》2003,13(4):463-468

Water vapour and CO2 fluxes were measured by the eddy-covariance technique above a mixed needle and broad-leaved forest with affiliated meteorological measurements in Changbai Mountain as part of China‘s FLUX projects since late August in 2002. Net water vapour exchange and environmental control over the forest were examined from September 1 to October 31 in 2002. To quantify the seasonal dynamics, the transition period was separated into leafed, leaf falling and leafless stages according to the development of leaf area. The results showed that (a) seasonal variation of water vapour exchange was mainly controlled by net radiation (Rn) which could account for 78.5%, 63.4% and 56.6% for leafed, leaf falling and leafless stages, respectively, while other environmental factors‘ effects varied evidently; (b) magnitude of water vapour flux decreased remarkably during autumn and daily mean of water vapour exchange was 24.2 mg m^-2 s^-1 (100%), 14.8 mg m^-2 s^-1 (61.2%) and 10.3 mg m^-2 s^-1 (42.6%) for leafed, leaf falling and leafless stage, respectively; and (c) the budget of water vapour exchange during autumn was estimated to be 87.1 kg H2O m2, with a mean of 1427.2 g H2O d^-1 varying markedly from 3104.0 to 227.5 g H2O m^-2d^-1.  相似文献   

汉江流域上游支流大型底栖动物群落结构特征与生物多样性     

闫云君  李晓宇 《湖泊科学》2007,19(5):585-591

2003年6月至2004年6月,对汉江流域上游支流--黑竹冲河的大型底栖动物群落结构与生物多样性进行了深入研究,结果表明:河流生物群落结构和生物多样性比较复杂,河流功能状况良好.在采集到的85种大型底栖动物中,昆虫占71种;群落表现出明显的时空特点,具边缘效应的第4采样点物种最丰富,2月份物种最多,达50种;生物多样性指数周年动态显示,第1采样点的物种多样性变动最为平稳,第5采样点变动最大,其它各点居中;各微生境中共有种占据优势,物种相似性均大于60%;群落春季的多样性高于夏季,夏季高于秋季;功能摄食群则以收集者占优,共计达68种.群落密度在1月份达到最大,为1843 ind/m2;而生物量则在10月份达到最大,为228.7393 g/m2.  相似文献   

山西省1998年秋,冬季偏暖干旱特征分析     

王巧霞  秦爱民 《山西气象》1999,(2):22-23,25

１气象概况自１９９８年９月以来,山西省降水连续偏少,气温持续偏高,秋、冬季全省平均降水量仅有３４毫米,较常年同期偏少７２％以上。且降水时空分布不均,降水过程主要集中在９８年９月１８～１９日,１０月２～４日及２４～２５日。小麦播种后１１月至今年３月上旬...  相似文献   

漯河市秋季强降水预报     

惠付梅胡燕平  单铁良 《气象与环境科学》2004,(1):18-19

利用1996～1998年9～11月份欧洲中心数值预报产品资料和日本传真图资料,根据不同天气类型,建立了漯河市秋季强降水预报方法.  相似文献   

吉林省2003年秋季天气气候特点及影响     

张丽 《吉林气象》2004,(1):20-21

2003年秋季(9—10月)我省总的气候特点是：气温偏高,中西部多数地方初霜偏晚,季内降水稍多,中西部地区出现大风日数少于常年。本文简要分析了2003年秋季天气气候的环流成因,对其给国民经济带来的影响进行了评述。  相似文献   

Autumn daily characteristics of land surface heat and water exchange over the Loess Plateau mesa in China   总被引：8，自引：0，他引：8  

文军  韦志刚  吕世华  陈世强  奥银焕  梁玲 《大气科学进展》2007,24(2):301-310

The Loess Plateau, located in northern China, has a significant impact on the climate and ecosystem evolvement over the East Asian continent. In this paper, the preliminary autumn daily characteristics of land surface energy and water exchange over the Chinese Loess Plateau mesa region are evaluated by using data collected during the Loess Plateau land-atmosphere interaction pilot experiment （LOPEX04）, which was conducted from 25 August to 12 September 2004 near Pingliang city, Gansu Province of China. The experiment was carried out in a region with a typical landscape of the Chinese Loess Plateau, known as ＂loess mesa＂. The experiment＇s field land utilizations were cornfield and fallow farmland, with the fallow field later used for rotating winter wheat. The autumn daily characteristics of heat and water exchange evidently differed between the mesa cornfield and fallow, and the imbalance term of the surface energy was large. This is discussed in terms of sampling errors in the flux observations-footprint; energy storage terms of soil and vegetation layers; contribution from air advections; and low and high frequency loss of turbulent fluxes and instruments bias. Comparison of energy components between the mesa cornfield and the lowland cornfield did not reveal any obvious difference. Inadequacies of the field observation equipment and experimental design emerged during the study, and some new research topics have emerged from this pilot experiment for future investigation.  相似文献   

秋季养生     

李慧敏 《河南国土资源》2008,(10)

秋天是万物成熟收获的季节,气候由热转凉而生燥,常见咽喉干燥、口舌少津、嘴唇干裂、鼻出血、便秘等症。燥邪易伤肺,还会引发干咳。所以秋天一定要注意养生,防止燥邪对人体的侵害。  相似文献   

2011年秋季（9—11月）山东天气评述     

张磊  李华  栾怀德  胡桂芳 《海洋气象学报》2011,(4):66-68

利用2011年9—11月山东省气温、降水资料以及500hPa月平均位势高度场、距平场等资料,结合逐日高空环流形势,分析了山东省2011年秋季天气特点、环流特征和主要天气过程,对季内的主要天气及其影响进行了评述。  相似文献