共查询到20条相似文献，搜索用时 15 毫秒
1.
The procedures involved in constructing data banks for use in climatological research are described, using examples from work done in the Climatic Research Unit. Such data banks will normally have two component parts: the meteorological records themselves, and the accompanying documentary and information systems.As a first step, meteorological records appropriate for the intended application of the data bank must be collected and stored, commonly in a computer. Individual records must then be merged into a form convenient for the user. For example, all records from one geographical region may be stored in one computer file. Procedures for quality control of the data are discussed. We emphasize the need to ensure that records are homogeneous, i.e., that they do not contain spurious jumps or trends caused by non-climatic factors such as site change or urbanization. Some techniques to correct inhomogeneities in meteorological records are described.The documentation accompanying the meteorological records enables users of the data bank to assess the suitability and reliability of the data. It has three components: first, information on the individual records such as start year, end year, altitude of the site, and geographical position; second, a list of data sources used in the compilation process; third, station histories which detail any known changes in site, instrumentation, etc. The station histories will be added to as work progresses on the data bank, to describe any attempts to homogenize records, and ultimately to give the compiler's assessment of the reliability of each record.User needs must be considered at all stages of data bank design and construction. Only in this way will a well-documented and easy-to-use system result. 相似文献
2.
Weather ‘records’ and climatic change 总被引：1，自引：0，他引：1
Douglas V. Hoyt 《Climatic change》1981,3(3):243-249
Much recent popular opinion indicates more weather records are being established now than in the past or what one would expect
by chance. The theory of extremes as applied to weather records is reviewed and then compared to the actual frequency of weather
records established in the United States. It is concluded that fewer extremes of temperature are being set in recent years
contrary to the popular view. Precipitation records are occurring at the normal theoretically expected rate. 相似文献
3.
使用均值生成函数、标准正态均一性检验方法和相关分析等方法对我国东部地区96个观测站1931—2020年夏季降水量长年代资料进行了一系列插补、检验、订正及效果分析等工作。结果表明：(1)均值生成函数拟合的1931—2020年各站夏季降水量资料的整体趋势和极值与观测值均有较好的一致性,其中无缺测资料的6个站点观测值和拟合值在距平符号一致率上达到了86.1%,可以满足插补工作的需要。(2)对1931—1950年和1951—2020年2个时段的夏季降水量资料,用平均值和方差2个统计量对插补后的资料进行差异性检验,共有8站具有显著性差异。(3)对插补后的1931—2020年夏季降水量资料进行了均一性检验和均一化订正,其中13站存在非均一性。(4)将订正后的站点资料与CRU＿TS4.05(University of East Anglia Climatic Research Unit Global 0.5°Monthly Time Series)数据库的格点资料进行空间分布相似度分析,2套资料在1931—1950、1951—2020和1931—2020年这3个时段的空间相关系数分别达到了0.90,... 相似文献
4.
The Statistical Prediction Of Offshore Winds From Land-Based Data For Wind-Energy Applications 总被引：3，自引：0，他引：3
John L. Walmsley Rebecca J. Barthelmie William R. Burrows 《Boundary-Layer Meteorology》2001,101(3):409-433
Land-based meteorological measurements at two locations on the Danish coast are used to predict offshore wind speeds. Offshore wind-speed data are used only for developing the statistical prediction algorithms and forverification. As a first step, the two datasets were separated into ninepercentile-based bins, with a minimum of 30 data records in each bin. Next, the records were randomly selected with approximately 70% of the data in each bin being used as a training set for development of the prediction algorithms, and the remaining 30% being reserved as a test set for evaluation purposes. The binning procedure ensured that both training and test sets fairly represented the overall data distribution.To base the conclusions on firmer ground, five permutations of these training and test sets were created. Thus, all calculations were based on five cases, each one representing a different random selection from the same data, but maintaining the (approximate) 70-30 split in each bin. This procedure served to ensure that conclusions were not based on a single randomly-selected case. Two statistical methods are employed:multiple linear regression (MLR), and Classification and Regression Trees(CART). MLR produces excellent results using only land-based predictors.The CART results are similar to those from MLR, and tend to be slightly better.Retired 相似文献
5.
The history of instrumental meteorological observations in Labrador/Nunatsiavut, Canada, began in August 1771 when the Unitas Fratrum, also known as the “Moravian Brethren”, established a mission among the Inuit on the Labrador coast. The Brethren named this place “Nain” after a city mentioned in the New Testament of the Bible. The missionaries included learned men, trained in the natural sciences, and in October of that same year they began to undertake instrumental meteorological observations. These observations have been continued, in one form or another, to the present day. As will be shown in this paper, the year 1771 thus marks the beginning of a long time series of meteorological observations from Labrador. The authors of this paper are currently researching the climatic history of the Labrador/Nunatsiavut region by tracing the meteorological observations of the Moravian missionaries to be found in scientific publications of the eighteenth, nineteenth and twentieth centuries. As will be demonstrated, the records of these observations in Labrador go through several stages; from being almost completely forgotten, to being published and republished in the main international meteorological journals. In this latter context, it may be said that the channels for the distribution of this knowledge are still being charted; this process involves tracking contacts between the Moravian Church and their sympathisers, as well as between the Church and contemporary scientists. This paper seeks to elucidate knowledge of these old records by placing them in the context of the research field of historical climatology and, at the same time, to honour the Moravian missionary observers for their valuable contribution to knowledge of past variations in climate. 相似文献
6.
Alexander Loew 《Theoretical and Applied Climatology》2014,115(3-4):427-440
Satellite-based observations provide a unique data record to study the Earth system. Recent efforts of the space agencies to reprocess the archives of satellite observations aim to provide Essential Climate Variable (ECV) data records for manifold applications in climate sciences. Varying lengths of a data record or gaps in a data time series are likely to affect the analysis results obtained from long-term satellite data records. The present paper provides a systematic assessment of the impact of variations in the observational record of terrestrial ECVs for selected climate applications like trend detection and the analysis of relationships between different ECVs. As an example, the Sahelian drought and the subsequent recovery in precipitation and vegetation will be analyzed in detail using observations of precipitation, surface albedo, vegetation index, as well as ocean indices. The paper provides a different perspective on the robustness of long-term satellite observations than previous studies. It shows in particular that the long-term significant trends in precipitation and vegetation dynamics are rather sensitive to the investigation period chosen and that small data gaps can already have a considerable influence on the analysis results. It is therefore a plea for continuous climate observations from space. 相似文献
7.
中国近代气象观测记录特点浅析 总被引：1，自引：0，他引：1
综合有关中国近代气象观测的史料文献和档案资料,对中国近代气象观测记录的存档现状及主要特点进行初步的论述和分析,对保护和开发利用近代历史气象资料、提供数据共享有一定的参考作用。 相似文献
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9.
William P. Elliott 《Climatic change》1995,31(2-4):349-367
Long-term temperature changes are expected to give rise to changes in the water vapor content of the atmosphere, which in turn would accentuate the temperature change. It is thus important to monitor water vapor in the troposphere and lower stratosphere. This paper reviews existing data for such an endeavor and the prospects for improvement in monitoring.In general, radiosondes provide the longest record but the data are fraught with problems, some arising from the distribution of stations and some from data continuity questions arising from the use of different measuring devices over both time at one place and over space at any one time. Satellite records are now of limited duration but they will soon be useful in detecting changes. Satellite water vapor observations have their own limitations; there is no one system capable of measuring water vapor over all surfaces in all varieties of weather. Among the needs are careful analysis of existing records, the collection of metadata about the measuring systems, the development of a transfer standard radiosonde system, and the commitment to maintaining an observing system dedicated to describing any climate changes worldwide. 相似文献
10.
Ming-Ko Woo 《Climatic change》1992,20(4):313-330
Stochastic modelling provides a tool for exploring the full implications of the statistical behavior of historical records and can be used to predict the changing probabilities that events of various magnitudes will occur for different climatic change scenarios. Two simulation models are presented, one for daily air temperature, and the other for daily precipitation. The simulation procedures are: (1) extract salient parameter values from historical records; (2) simulate long sequences of data using the stochastic models, with or without a climatic change scenario as provided by a general circulation model; and (3) using the simulated data as inputs, derive the probability distributions of other variables based on known deterministic or probabilistic relationships between the input and the predicted variables.Given a doubling of carbon dioxide concentration in the atmosphere, the climatic models produce varying degrees of temperature and precipitation changes. Examples of application, including the derivation of snowfall and riverice data using simulated temperature and precipitation, illustrate that stochastic modelling offers a suitable approach to quantify the possible hydrologic impacts of climatic change. 相似文献
11.
Steven P. Hamburg Matthew A. Vadeboncoeur Andrew D. Richardson Amey S. Bailey 《Climatic change》2013,116(3-4):457-477
Observing the full range of climate change impacts at the local scale is difficult. Predicted rates of change are often small relative to interannual variability, and few locations have sufficiently comprehensive long-term records of environmental variables to enable researchers to observe the fine-scale patterns that may be important to understanding the influence of climate change on biological systems at the taxon, community, and ecosystem levels. We examined a 50-year meteorological and hydrological record from the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, an intensively monitored Long-Term Ecological Research site. Of the examined climate metrics, trends in temperature were the most significant (ranging from 0.7 to 1.3 °C increase over 40–50 year records at 4 temperature stations), while analysis of precipitation and hydrologic data yielded mixed results. Regional records show generally similar trends over the same time period, though longer-term (70–102 year) trends are less dramatic. Taken together, the results from HBEF and the regional records indicate that the climate has warmed detectably over 50 years, with important consequences for hydrological processes. Understanding effects on ecosystems will require a diversity of metrics and concurrent ecological observations at a range of sites, as well as a recognition that ecosystems have existed in a directionally changing climate for decades, and are not necessarily in equilibrium with the current climate. 相似文献
12.
自然物候观测中存在的问题及解决方法 总被引：1，自引：0，他引：1
全球变暖使动植物等物候期发生着显著的变化。利用青海省1994-2003年的草本、木本、动物物候期及气象水文现象观测记录,统计了其中发生的各类错情,归纳分析了错情发生的原因,提出了减少、消除自然物候期观测记录错情的技术途径。旨在促进自然物候观测资料质量的进一步提高。 相似文献
13.
利用1961—2004年我国西南地区322个站的气温观测资料, 分析了乡村站、小城市站、大中城市站和国家基准/基本站气温变化趋势特点, 着重研究了城市化对城镇站和国家站地面气温记录的影响程度和相对贡献比例。结果显示:区域平均的各类台站年平均气温呈现不同程度的上升趋势, 城市站、国家站的增温速率均高于乡村站。大中城市站和国家站的年平均热岛增温率分别为0.086 ℃/ 10a和0.052 ℃/10a, 其增温贡献率分别达57.6%和45.3%。与大多数地区不同, 西南地区的增温速率明显偏小。因此, 尽管平均热岛强度变化比许多地区弱, 但其相对贡献明显, 表明城市化对该区域气温趋势的绝对影响较弱, 但相对影响较强。另外, 城市热岛增温有明显的季节变化, 表现为秋季最强, 春季或冬季次之, 夏季最弱。热岛增温贡献率则为春季最大 (100%), 夏季次之 (73%以上), 秋季和冬季相对较小。这主要是因为春、夏两季背景气候变凉或趋势微弱, 热岛增温在实际增温中占有更高的比例。 相似文献
14.
利用全国探空系统换型时获取的70个高空台站的对比观测数据,计算了59型探空仪和L波段探空仪温度和位势高度的差异,分析了探空仪换型对于探空数据一致性的影响。结果表明:就全国平均而言,在100 hPa特别是在400 hPa以下高度,两套系统提供的温度和位势高度观测值没有明显的系统差异;但在70 hPa以上高空,59型探空仪测定的规定等压面温度比L波段探空仪低0.1～0.7℃,导致位势高度在20 hPa高度时偏低达30 m左右,换型前后变化明显。系统差异的产生与59型探空仪的生产厂家、施放地区和季节关系较大,进一步分析表明:太原厂生产的探空仪测得的温度在对流层偏高,在平流层偏低,位势高度在对流层偏高,在平流层逐步转为偏低;上海厂生产的探空仪测得的温度全程偏低,引起位势高度也全程偏低,因此两个厂家的59型探空仪相对于L波段的温度和位势高度系统差也有明显不同。用户在使用局部地区高空站59型探空仪的观测数据时需了解该59型探空仪的生产厂家。 相似文献
15.
Multi-Century Tree-Ring Reconstructions of Colorado Streamflow for Water Resource Planning 总被引：3，自引：0，他引：3
Water resource management requires knowledge of the natural variability in streamflow over multiple time scales. Reconstructions of streamflow derived from moisture-sensitive trees extend, in both time and magnitude, the variability provided by relatively short gage records. In this study, we present a network of 14 annual streamflow reconstructions, 300–600 years long, for gages in the Upper Colorado and South Platte River basins in Colorado generated from new and existing tree-ring chronologies. Gages for the reconstruction were selected on the basis of their importance to two of the largest Colorado Front Range water providers, who provided the natural flow data for the calibration with tree-ring data. The reconstruction models explain 63–76% of the variance in the gage records and capture low flows particularly well. Analyses of the reconstructions indicate that the 20th century gage record does not fully represent the range of streamflow characteristics seen in the prior two to five centuries. Multi-year drought events more severe than the 1950s drought have occurred, notably in the 19th century, and the distribution of extreme low flow years is markedly uneven over the past three centuries. When the 14 reconstructions are grouped into Upper Colorado, northern South Platte, and southern South Platte regional flow reconstructions, the three time series show a high degree of coherence, but also time-varying divergences that may reflect the differential influence of climatic features operating in the western U.S. These reconstructions are currently being used by water managers to assess the reliability of water supply systems under a broader range of conditions than indicated by the gage records alone. 相似文献
16.
The multifractal properties and scaling behaviors of the long-term and recent 2000-year δ 18 O records of NGRIP ice core are investigated by the multifractal detrended fluctuation analysis method. The generalized Hurst exponents, multifractal scaling exponents, and singularity spectrums of two δ 18 O records are derived to verify the multifractiality of two records. And the multifractal behaviors of two records are obviously different, which may reflect the climate change of the recent 2000-year time is quite different from one of the long-term time. In addition, the probability distribution analysis of two δ 18 O records is presented to manifest the different multifractality between two δ 18 O records of NGRIP ice core. Our results will be helpful to research the climate change. 相似文献
17.
气象辐射观测数据是气象业务、服务和科学研究的基础,其质量控制很重要。本文通过对近几年甘肃省地面气象辐射观测记录中出现的问题进行梳理,根据地面气象观测规范要求和实际工作中的审核经验,对气象辐射观测记录的质量控制方法及容易发生异常的地方进行总结,以期对台站提高辐射月报表数据文件的质量提供参考,对从事省级气象数据质量控制工作尤其是刚从事该项工作的人员的提供有益的帮助。结果显示:仪器正常时的异常记录参考云量云状、能见度、天气现象、定时降水量等气象要素进行人工判别,是现阶段气象辐射数据质量控制的最有效办法;对于仪器故障时的异常记录的判别要分情况考虑,遵从业务规定的方法取代异常值和缺测值;对于记录中容易出错的其他问题,则需要台站观测员及质量控制人员加强业务学习,总结工作经验,避免类似问题再次出现。 相似文献
18.
该文研究了利用多普勒雷达径向速度资料识别低空风切变和辐合线的方法, 讨论了不同的计算“窗口”大小对资料预处理效果和梯度计算的影响, 并对几次强对流天气进行识别、分析。结果表明:预处理采取先中值滤波后滑动平均, 选择合适的“窗口”能在有效去除库间脉动的同时保持中尺度信息; 经过资料预处理后, 从径向速度计算的切变结果与径向速度中反映的中尺度结构比较一致, 能够从这些资料中自动提取辐合和切变的中尺度信息; 强降水回波与风切变高值区位置、变化趋势一致; 垂直切变能够提供径向风场的高低层配置信息; 利用径向速度资料可以实现对风切变和辐合线的自动识别, 为灾害性天气预警、预报提供重要的客观依据。 相似文献
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20.
In this study,records from a 3-yr intensified observational experiment at eight stations along the hillside of Seqilashan over the southeastern Tibetan Plateau were analyzed and combined with records at 28 routine observation stations in the Chinese National Meteorological Station Network to investigate the influences of station location on the different diurnal rainfall variations between station records and Tropical Rainfall Measuring Mission (TRMM) data products.The results indicate that the diurnal variation of warm season rainfall is closely related to location of stations.The prevailing nocturnal rainfall peak in observations at routine stations can be largely attributed to the relatively lower location of the stations,which are mostly situated in valleys.The records at Seqilashan stations on hillsides revealed an evident diurnal afternoon peak of warm season rainfall,similar to that indicated by TRMM data.The different diurnal phases between valley and hillside stations are closely related to the orographically induced regional circulations caused by the complex topography over the Tibetan Plateau.The results of this study indicate that the prevailing nocturnal rainfall associated with the relatively lower location of routine observation stations can partially explain the diurnal rainfall variations between observation station records and TRMM data. 相似文献