3套资料中西北太平洋热带气旋活动特征的比较分析          下载免费PDF全文

张冬娜  张翰  程旭华  陈大可 《海洋学研究》2020,38(3):48-57

本文使用中国气象局、美国联合台风预警中心和日本气象厅的3套热带气旋最佳路径资料(CMA资料、JTWC资料和RSMC资料)分析了1951—2016年西北太平洋热带气旋活动特征。3套资料反映的结果如下:热带气旋主要发生在10°N—25°N范围内,且1980年前其位置点在纬度上有南移的变化趋势,1980年后则相反;移速主要分布在2~6 m/s区间,在25°N左右移速明显加快,1980年前移速呈显著减小趋势;最大持续风速主要分布在10~15 m/s区间,1980年前最大持续风速有减小趋势;在风速较大的区域热带气旋最大风速半径较小,2001—2016年热带气旋和台风最大风速半径每年分别减小0.46 km和0.54 km。CMA和RSMC资料的结果高度一致,而JTWC资料结果与它们都存在一定的差异。热带气旋位置点频数和强度的变化受资料间差异的影响较大,而其位置及移速的变化则受影响较小。  相似文献   

北半球热带中太平洋与印度洋海表温度梯度对夏季西北太平洋热带气旋生成频数变化的影响     

方珂  余锦华 《热带海洋学报》2019,38(5):42-51

基于1951—2018年哈德里中心海温资料、美国气象环境预报中心和美国国家大气研究中心再分析资料和第四代欧洲中心汉堡模式, 针对1994年、2018年等西北太平洋热带气旋(TC)生成异常多的年份, 研究了引起TC增加的海表温度异常(SSTA)模态及其影响机制。结果表明, 北半球热带中太平洋增暖与印度洋变冷是夏季西北太平洋TC生成频数增加的主要原因, 北大西洋负三极型式SSTA促使TC生成的进一步增加。热带中太平洋增暖与印度洋冷却在菲律宾以东激发出西风异常和气旋性环流异常。北大西洋负三极型式SSTA在我国南海、菲律宾至东南沿岸激发出气旋性环流异常。前者在西北太平洋中部, 后者在南海产生有利于TC生成的局地环境。1994年和2018年夏季热带中太平洋出现暖SSTA、印度洋为冷SSTA、北大西洋呈现负三极型式SSTA, 西北太平洋TC生成频数极端增多。近30年来, 当出现热带中太平洋增暖和印度洋冷却时, 北大西洋表现出比1989年以前更强的负三极型式SSTA, 使西北太平洋TC生成频数和北半球热带印度洋-太平洋SSTA梯度的线性相关更显著。  相似文献   

Rainfall–runoff responses on Arctic hillslopes underlain by continuous permafrost,North Slope,Alaska, USA          下载免费PDF全文

Caitlin R. Rushlow  Sarah E. Godsey 《水文研究》2017,31(23):4092-4106

The Arctic hydrologic cycle is intensifying, as evidenced by increased rates of precipitation, evapotranspiration, and riverine discharge. However, the controls on water fluxes from terrestrial to aquatic systems in upland Arctic landscapes are poorly understood. Upland landscapes account for one third of the Arctic land surface and are often drained by zero‐order geomorphic flowpath features called water tracks. Previous work in the region attributed rapid runoff response at larger stream orders to water tracks, but models suggest water tracks are hydrologically disconnected from the surrounding hillslope. To better understand the role of water tracks in upland landscapes, we investigated the surface and subsurface hydrologic responses of 6 water tracks and their hillslope watersheds to natural patterns of rainfall, soil thaw, and drainage. Between storms, both water track discharge and the water table in the hillslope watersheds exhibited diel fluctuations that, when lagged by 5 hr, were temporally correlated with peak evapotranspiration rate. Water track soils remained saturated for more of the summer season than soils in their surrounding hillslope watersheds. When rainfall occurred, the subsurface response was nearly instantaneous, but the water tracks took significantly longer than the hillslopes to respond to rainfall, and longer than the responses previously observed in nearby larger order Arctic streams. There was also evidence for antecedent soil water storage conditions controlling the magnitude of runoff response. Based on these observations, we used a broken stick model to test the hypothesis that runoff production in response to individual storms was primarily controlled by rainfall amount and antecedent water storage conditions near the water track outlet. We found that the relative importance of the two factors varied by site, and that water tracks with similar watershed geometries and at similar landscape positions had similar rainfall–runoff model relationships. Thus, the response of terrestrial water fluxes in the upland Arctic to climate change depends on the non‐linear interactions between rainfall patterns and subsurface water storage capacity on hillslopes. Predicting these interactions across the landscape remains an important challenge.  相似文献   

SERIALS     

《Abstract of Chinese Geological Literature》2014,(2)

正Acta Geographica Sinica ISSN0375-5444 CN11-1856/P Acta Geologica Sichuan ISSN1006-0995 CN51-1273/P Acta Geologica Sinica ISSN0001-5717 CN11-1951/P Acta Geologica Sinica(English Edition)ISSN1000-9515 CN11-2001/P Acta Geoscientica Sinica ISSN1006-3021 CN11-3474/P Acta Micropalaeontologica Sinica ISSN1000-0674 CN32-1189/Q  相似文献   

利用OpenGL实现武器装备模型运动可视化     

岳利群  夏青  黄勇  孟岩斌 《测绘科学》2010,35(6):120-122

在对武器装备模型的研究中,武器空间运动轨迹的研究和运动中产生的特殊效果的研究是当前重要的两个研究方向。本文研究的相关技术主要应用于某单方仿真推演系统,以飞机、导弹、炮弹等为研究对象,通过对武器装备的空间运动轨迹建模,建立了参数可变的轨迹解算方程,并且在三维可视化环境下模拟了其运动轨迹,同时利用粒子系统的方法模拟了飞机运动时产生的特殊效果。最终建立一个多视点、多角度、多层次观察武器运动仿真进度的可视化平台。  相似文献   

闸坡站风暴潮增水与热带气旋登陆点及路径的关系     

魏晓宇  刘雪峰 《台湾海峡》2010,29(1):122-127

将1992～2006年15a间影响和登陆闸坡站的热带气旋按照登陆点和移动路径进行分类．研究各类热带气旋在闸坡站引起的风暴潮增水峰值的出现时间与热带气旋登陆点及移动路径的关系，定性分析热带气旋风场结构对风暴潮增水的影响并经过2007年至今风暴潮增水预报过程中的实例检验．结果表明：闸坡站的增水类型与热带气旋的登陆地点和路径关系密切．在闸坡站登陆的东北行热带气旋引起的风暴潮增水多出现在登陆前，其他路径则出现在登陆时或登陆后；在闸坡以西登陆的热带气旋引起的风暴潮增水峰值一般发生在登陆时或登陆后1h以内；在闸坡站以东登陆的热带气旋引起的风暴潮增水峰值一般发生在登陆前10h以上；而其他类型的热带气旋引起的风暴潮增水由于个例较少规律尚不明显．  相似文献   

Thermal history of the Hodgkinson Province and Laura Basin,Queensland: Multiple cooling episodes identified from apatite fission track analysis and vitrinite reflectance data     

S. J. Marshallsea  P. F. Green  J. Webb 《Australian Journal of Earth Sciences》2013,60(4):779-797

Apatite fission track analysis and vitrinite reflectance data from outcrop and well samples in the Hodgkinson Province and Laura Basin reveal regional Cretaceous cooling. Apatite fission track analysis appears to define two discrete cooling episodes, in the mid‐Cretaceous (110–100 Ma) and Late Cretaceous (80–70 Ma), although in most samples data allow only definition of a single episode. Rocks now at outcrop cooled from Cretaceous palaeotemperatures generally between 50 and 130°C in the south of the region, and from >100°C in the north. Some samples from the Hodgkinson Province also show evidence for an Early Jurassic cooling episode, characterised by maximum palaeotemperatures varying from at least 95°C (from apatite fission track analysis) to ～200–220°C (from vitrinite reflectance), with cooling beginning at around 200 Ma. Apatite fission track analysis data do not reveal the earlier event in the Laura Basin, but on the basis of vitrinite reflectance data from Permian? units this event is also inferred to have affected the pre‐Jurassic basin units in this region. The regional extent of the Cretaceous cooling episode in the Hodgkinson Province suggests that the elevated palaeotemperatures in this region were most likely due to greater depth of burial, with subsequent cooling due to kilometre‐scale denudation. For a palaeogeothermal gradient of 30°C/km and a palaeosurface temperature of 25°C the total degree of Cretaceous cooling experienced by the samples corresponds to removal of between ～0.8 and >3.0 km of Triassic and younger section removed by denudation, beginning some time between ca 110 and 80 Ma. Higher palaeogradients would require correspondingly lower amounts of removed section. The geology of the Laura Basin suggests that an explanation of the observed Cretaceous palaeotemperatures in this region in terms of deeper burial may be untenable. Heating due to hot fluid flow may be a more realistic mechanism for producing the observed Cretaceous palaeothermal effects in the Laura Basin.  相似文献   

南海夏季风爆发与西北太平洋热带气旋活动   总被引：1，自引：0，他引：1  

黄菲  李元妮 《中国海洋大学学报(自然科学版)》2010,40(8)

利用1965—2007年美国台风预警中心(JTWC)的热带气旋(TC)及NCEP/NCAR再分析资料,初步研究南海夏季风爆发与西北太平洋(包括南海)热带气旋活动之间的关系。结果表明,南海夏季风的爆发伴随着西北太平洋(尤其南海区域)TC生成个数和活动频数比爆发前有显著增加,而超过1/2的年份南海夏季风爆发前2候和爆发候西北太平洋(150°E以西)有TC活动,表明TC活动可能是南海夏季风爆发的触发机制之一。在大多数(77%)南海夏季风爆发偏早年,爆发前2候和爆发候西北太平洋TC活动偏多,且TC生成位置偏西;而大多数(77%)爆发偏晚年份,爆发前2候和爆发候没有TC活动。季风的偏早爆发受季节内振荡、西北太平洋TC活动、中纬度冷空气活动等复杂因素影响,而季风的偏晚爆发则主要受季节内振荡影响。  相似文献   

爆发性气旋的前世今生     

傅刚  陈莅佳  李鹏远  庞华基  张树钦 《气象》2021,(3):261-273

温带气旋是中纬度地区每日天气舞台上最重要的“演员”。在秋冬季节的中高纬度海洋上有一类快速发展的温带气旋——“爆发性气旋”,尚未受到公众的广泛关注。文章围绕这一主题,首先回顾了温带气旋研究的历史,介绍了“爆发性气旋”这一术语产生的渊源,并对多位学者给出的爆发性气旋定义进行了系统梳理,重点介绍了一个考虑风速影响的、修正的爆发性气旋定义,还总结了爆发性气旋的研究现状,最后对其未来数十年的研究前景进行了阐述展望。  相似文献   

2007—2017年浙江省雷暴路径时空特征分析     

崔雪东  张卫斌 《气象与环境学报》2021,37(1):59-66

基于浙江省ADTD二维闪电定位系统监测的近11 a（2007—2017）地闪数据,采用密度极大值快速搜索聚类算法和Kalman滤波算法实现对雷暴的识别及其路径的追踪,并探讨大范围雷暴过程的时空分布特征。结果表明：该方法能够有效对浙江省各类雷暴的识别追踪,共筛选出261条雷暴过程的路径,其存在明显的年变化和年际变化,年路径数与年地闪频次存在较好的对应关系,月分布上路径数呈双峰分布,峰值分别在初春和夏季,其中春季雷暴路径移动时长高于其他季节。88.51%的雷暴自西向东移动,且偏北方向多于偏南方向,各移动方向上雷暴路径数的月分布存在差异性,春季雷暴移动的方向相比夏季较为集中,夏季雷暴各月最为主导的移动方向各不相同;雷暴的移动速度主要集中在50 km/h左右,自西-东和西南-东北方向移动的雷暴速度快于其他方向;空间分布上,主要存在两个移动通道,一是沿金衢盆地、绍兴和宁波方向的区域,其次是天目山脉以北的湖州嘉兴平原一带;从地形特征来看,路径主要发生在丘陵地带,平原及山地相对偏少,且地势越高路径越少。  相似文献