Medieval Warming, Little Ice Age, and European impact on the environment during the last millennium in the lower Hudson Valley, New York, USA   总被引：1，自引：0，他引：1  

Dee Cabaniss Pederson  Dorothy M. Peteet  Dorothy Kurdyla  Tom Guilderson 《Quaternary Research》2005,63(3):363-249

Establishing natural climate variability becomes particularly important in large urban areas in anticipation of droughts. We present a well-dated bi-decadal record of vegetation, climate, land use, and fire frequency from a tidal marsh in the Hudson River Estuary. The classic Medieval Warm Period is evident through striking increases in charcoal and Pinus dominance from 800–1300 A.D., paralleling paleorecords southward along the Atlantic seaboard. Higher inputs of inorganic sediment during this interval suggest increased watershed erosion during drought conditions. The presence of the Little Ice Age ensues with increases in Picea and Tsuga, coupled with increasing organic percentages due to cooler, moister conditions. European impact is manifested by a decline in arboreal pollen due to land clearance, increased weedy plant cover (i.e., Ambrosia, Plantago, and Rumex), and an increase in inorganic particles to the watershed.  相似文献   

Analyzing snowfall variability over two locations in Kashmir,India in the context of warming climate     

《Dynamics of Atmospheres and Oceans》2017

Present study focuses on examination snowfall variability over Gulmarg and Pahalgam of Kashmir Valley in India during past 31 years (1980–2010). Trends in temperature over the study area is also explored. Minimum and maximum temperature shows increasing trends which is consistent with increase in black carbon column mass density. Increase in black carbon mass density is attributed to urbanization over study area. Trends of minimum temperature is statistically significant. It is reported that snowfall over the Pahalgam shows decreasing trend except for the month of February and January. Pahalgam shows a significant decreasing trend in snowfall of about 48 mm per decade during March. Pahalgam and Gulmarg show seasonal decreasing trends of snowfall of about 15 mm and 1.8 mm per decade, respectively. These decreasing trends in snowfall are consistent with decadal increasing trends of about 1.2 °C and 0.8 °C in minimum temperature over Pahalgam and Gulmarg, respectively. Seasonal snowfall over both the regions shows decreasing trend (insignificant). Results reported in this study show a decrease of about 24.16% ± 9.86% per degree increase in minimum temperature over Pahalgam. Changing characteristics of snowfall in the context of anthropogenic warming present major challenges to the tourism and socioeconomic aspects over the Valley.  相似文献   

中国近117年年平均气温变化的区域特征研究   总被引：40，自引：2，他引：38  

屠其璞邓自旺  周晓兰 《应用气象学报》1999,10(Z1):1

用ＲＥＯＦ法以１６０站近４７年的年平均气温变化为依据将我国分为８个年平均气温变化区．以国内及临近国家长资料序列为基础,建立了反映我国各区及全国近１１７年的年平均气温标准化序列．从近１１７年气温变化来看,Ｉ～ＶＩＩ区都有升温趋势,全国平均气温的升温趋势为０．７６℃／１００ａ,北半球陆地则为０．６４℃／１００ａ．最大的为东北,华北、新疆,最小的为四川、贵州．从年代际尺度看我国与北半球陆地的平均气温的变化是相当一致的,相关系数高达０．９３,主要差别在于年际变化．  相似文献   

1951—2009年中国不同区域气温和降水量变化特征     

虞海燕  刘树华  赵娜  李栋  于永涛 《辽宁气象》2011,(4):1-11

为了研究中国不同区域气候变化特征,将全国按照气候区域划分为11个气候区,并利用1951—2009年中国194个国家基本/基准站月、年气温和降水观测资料,对全国及每个气候区平均温度及降水量的年和季节变化特征进行分析。结果表明：中国及各地区增温趋势均为极显著增加,尤其近20 a增温速度更快;而2007年成为有记录以来最暖的一年;中国冬季平均温度上升趋势最明显,春季次之,夏季几乎没有变化。中国平均年总降水量20世纪50年代最多,2000年代最少;而华北地区的年降水量减少最快;在四季降水中,中国只有夏季降水量波动略有增加,且各区域降水分布具有明显的南北差异特征。  相似文献   

太原市温度的时空变化特征     

郭雪 《山西气象》2011,(3):19-22

利用太原市1951年-2010年的实测气象资料,采用线性趋势分析、累计距平、Mann—Kendall方法,分析了太原市年均气温、平均最高气温、平均最低气温、02时平均气温、14时平均气温的变化趋势。得出了太原市总体上呈现增暖趋势,从1977年开始出现了显著增温;夜间气温增温幅度高于白天增温幅度,冬季增温幅度高于夏季增温幅度;最低平均气温的增温幅度最大等结论。  相似文献   

1951—2009年中国不同区域气温和降水量变化特征   总被引：18，自引：1，他引：17       下载免费PDF全文

虞海燕  刘树华  赵娜  李栋  于永涛 《气象与环境学报》2011,27(4):1-11

为了研究中国不同区域气候变化特征,将全国按照气候区域划分为11个气候区,并利用1951—2009年中国194个国家基本/基准站月、年气温和降水观测资料,对全国及每个气候区平均温度及降水量的年和季节变化特征进行分析。结果表明：中国及各地区增温趋势均为极显著增加,尤其近20 a增温速度更快;而2007年成为有记录以来最暖的...  相似文献   

A Crustal Upheaval in a Coastal Zone After Ocean Water Loading     

Shigehisa Nakamura 《Marine Geodesy》2001,24(4):229-235

A crustal upheaval in a coastal zone is studied by introducing a simplified theoretical model of an equivalent elastic plate on which oceanic water is acting as a static loading. With a solution for the plate, the author notes what is seen as a crustal upheaval under the loading of static oceanic water in a qualitative scope. The solution requires some assumed parameters for the plate and the loading. Some other conditions should be also given to realize a possible dynamical understanding of a sea level rise seen after global climatological warming and glacial melting.  相似文献   

Harnessing scientific and local knowledge to face climate change in small-scale fisheries     

《Global Environmental Change》2021

Small-scale fisheries in developing regions are particularly vulnerable to climate change, but the assessment of climate-induced changes and impacts are often hampered by the data poor-situation of these social-ecological systems. Based on 40 years of scientific and local ecological knowledge, we provide a coherent narrative about the effects of a marine hotspot of climate change on a small-scale fishery across different geographical and temporal scales. We applied a mixed-methods approach to assess biophysical changes, social-ecological impacts, and the incremental spectrum of actions implemented at multiple levels to increase the adaptive capacity of a small-scale clam fishery. The warming hotspot here analyzed was the fastest-warming region in the South Atlantic Ocean. Long-term changes in wind intensity and direction were also noticeable at a regional scale. Both sea surface temperature and winds showed a clear shifting pattern in the late 1990 s. These climate-related stressors determined ecosystem and targeted population changes (e.g. clam mass mortalities, slow stock recovery rates after ecological shocks, habitat narrowing), and favored harmful algal bloom-forming organisms. Climate-induced drivers also affected the human component of the social-ecological system, preventing fishers from securing a fulltime livelihood and limiting the fishery economic potential. Adaptive responses at multiple levels provided some capacity to address climate change effects, and transformative pathways are being taken to adapt to climate-induced changes over the long-term. Transformative changes were fostered by the local perception of environmental change, shared narratives, sustained scientific monitoring programs, and the interaction between knowledge systems, facilitated by a bridging organization within a broader process of governance transformation. The combination of autonomous adaptations (based on linking social capital and fishery leaders agency) and government-led adaptations were essential to face the challenges imposed by climate change. Our results serve as a learning platform to anticipate threats and envision solutions to a wide range of small-scale fisheries in fast-warming regions worldwide.  相似文献   

1976-2017年乌鲁木齐市升温对季节的影响     

张月华  王健  蒋慧敏 《沙漠与绿洲气象(新疆气象)》2019,13(4):96-102

本文采用乌鲁木齐市国家基准气象站463站的逐日平均、逐日最低和逐日最高气温资料,分析了乌鲁木齐市1976-2017年气温变化趋势和对四季的影响。结果表明：乌市气温有明显上升的趋势,年平均气温的线性增温速率为0.50℃/10a,1997年出现了最暖年,1976年以来最暖的10 a均出现在20世纪末至今;年平均最低气温升温趋势最为明显,倾向率为0.77℃/10a,上升速率约是年平均最高气温的2.5倍;气温上升导致春季和夏季的开始日期提前明显、秋季和冬季开始日期有推后的趋势,使得夏季明显延长,延长率为5.9d/10a,近42a来共增加25d,其他季节则有不同程度的缩短,其中冬季缩短最为明显,缩短率为-3.6d/10a,近42a来共缩短了15d;各季节开始日期不仅与年平均气温相关性很好,且开春期、入夏期分别与3月和6月平均气温显著负相关;入秋期与入冬期分别与9月和11月气温呈显著正相关;夏季和冬季的长度也与年平均气温显著相关,当年平均气温每上升1℃时,夏季将延长6d,而冬季则会缩短7 d。  相似文献   

Geographical patterns of tree-limits of Norway spruce and Scots pine in the southern Swedish Scandes     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):237-245

The tree-limit altitudes of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) from 180 sites (within an area of 95?km?×?165?km) in the southern Scandes were correlated with the geographical variables latitude, longitude and distance to the sea. The results were compared with a similar investigation of the tree-limit of mountain birch (Betula pubescens Ehrh. ssp. tortuosa (Ledeb.) Nyman) in the same area. The three tree-limit altitudes showed good negative correlation with latitude, poor correlation with longitude and good positive correlation with the distance to the sea, suggesting that on a regional scale the altitudes are controlled by macroclimate. At some sites, local topoclimatic features, some of which were partially aspect-dependent, may cause deviations in the regional pattern of tree-limit altitude that is set primarily by summer temperature. Tree-limit responses to potential future climate warming will probably differ substantially in magnitude from site to site in relation to local topography and associated ecological constraints.  相似文献