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气象条件对浙江省泡桐物候期的影响研究 总被引:2,自引:1,他引:2
利用气候资料及泡桐物候期数据,分析了浙江省泡桐关键生育期与相关气象要素的关系,研究了泡桐开花展叶前相关气候特征,探讨了冷空气对泡桐秋季物候期的可能影响。从统计值的关系来看,其物候期主要取决于气温及≥10℃有效积温的高低,降水量的影响其次,日照时数的影响最小。泡桐物候期对当季的气温条件非常敏感,降水对其开花、展叶的影响有滞后作用。泡桐开花和展叶始期前3个月的≥10℃有效积温一般分别要达到200℃·d和300℃·d以上;由落叶末期至下一年开花和展叶始期的≥10℃有效积温也分别要基本达到200℃·d和300℃·d以上;开花展叶前3个月的降水量和日照时数一般在230 mm和在210 h以上。泡桐秋季物候期前7 d内的冷空气,特别是中等强度以上的冷空气对其影响很大,落叶前的冷空气促使泡桐开始落叶,落叶开始后,冷空气将加速落叶。开花末期前2周的冷空气,在一定程度上促进了泡桐花期的结束。 相似文献
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Mean seasonal and spatial variability in global surface air temperature 总被引:16,自引:1,他引:16
Summary Using terrestrial observations of shelter-height air temperature and shipboard measurements, a global climatology of mean monthly surface air temperature has been compiled. Data were obtained from ten sources, screened for coding errors, and redundant station records were removed. The combined data base consists of 17 986 independent terrestrial station records and 6 955 oceanic grid-point records. These data were then interpolated to a 0.5° of latitude by 0.5° of longitude lattice using a spherically-based interpolation algorithm. Spatial distributions of the annual mean and intra-annual variance are presented along with a harmonic decomposition of the intra-annual variance.With 7 Figures 相似文献
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为深入了解气象探测环境对气温观测数据的影响,利用2017年北京市观象台(54511)与南海子站(A1274)逐小时地面气象要素数据,分析两站气温差异以及因站点探测环境导致的日照、风速和降水对两站气温差异的影响。结果表明:2017年两站气温差异较明显,年平均气温54511站比A1274站高0.75℃;两站逐月平均气温54511站全年高于A1274站,两站差值7月最低为0.60℃,9月最高为1.09℃;两站平均日最高气温较接近,平均日最低气温差异较大,54511站较A1274站高1.24℃;两站气温的日变化特征相似,呈单峰分布,54511站气温日较差低于A1274站。两站小时气温差值随着日照时长和强度的增加而增加,短波辐射效应最强的10-14时和长波辐射效应最强的19-23时两站气温差值与当日白天直接辐射曝辐量的相关系数分别为0.459和0.601;水平风速对两站气温差值的影响较大。水平风速超过5 m·s-1时,两站气温差小于0.1℃;当水平风速不超过1 m·s-1时,两站观测气温差值达到1.28℃;降水天气下两站的气温差值小于非降水天气,出现降水时次54511站平均气温仅比A1274站高0.2℃。两站相距4.3 km,气候均一,测站周边2 km范围内建设用地占比54511站比A1274站高约30%,植被占比低28%,水体占比相差不大。另外,54511站附近的五环路具有低反射率和高热容的特征,白天能够吸收太阳辐射储存较多的热量,这些热量在夜间释放,可能是两站探测环境对太阳辐射吸收的差异决定了两站温差受太阳辐射和风速的影响较大,而受降水影响较小。 相似文献
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Marcelo de Carvalho Alves Luiz Gonsaga de Carvalho Rubens Leite Vianello Gilberto C. Sediyama Marcelo Silva de Oliveira Arionaldo de Sá Junior 《Theoretical and Applied Climatology》2013,113(1-2):155-174
The objective of the present study was to use the simple cokriging methodology to characterize the spatial variability of Penman–Monteith reference evapotranspiration and Thornthwaite potential evapotranspiration methods based on Moderate Resolution Imaging Spetroradiometer (MODIS) global evapotranspiration products and high-resolution surfaces of WordClim temperature and precipitation data. The climatic element data referred to 39 National Institute of Meteorology climatic stations located in Minas Gerais state, Brazil and surrounding states. The use of geostatistics and simple cokriging technique enabled the characterization of the spatial variability of the evapotranspiration providing uncertainty information on the spatial prediction pattern. Evapotranspiration and precipitation surfaces were implemented for the climatic classification in Minas Gerais. Multivariate geostatistical determined improvements of evapotranspiration spatial information. The regions in the south of Minas Gerais derived from the moisture index estimated with the MODIS evapotranspiration (2000–2010), presented divergence of humid conditions when compared to the moisture index derived from the simple kriged and cokriged evapotranspiration (1961–1990), indicating climate change in this region. There was stronger pattern of crossed covariance between evapotranspiration and precipitation rather than temperature, indicating that trends in precipitation could be one of the main external drivers of the evapotranspiration in Minas Gerais state, Brazil. 相似文献
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Quantifying the influence of land-use and surface characteristics on spatial variability in the urban heat island 总被引:1,自引:0,他引:1
The urban thermal environment varies not only from its rural surroundings but also within the urban area due to intra-urban differences in land-use and surface characteristics. Understanding the causes of this intra-urban variability is a first step in improving urban planning and development. Toward this end, a method for quantifying causes of spatial variability in the urban heat island has been developed. This paper presents the method as applied to a specific test case of Portland, Oregon. Vehicle temperature traverses were used to determine spatial differences in summertime ~2 m air temperature across the metropolitan area in the afternoon. A tree-structured regression model was used to quantify the land-use and surface characteristics that have the greatest influence on daytime UHI intensity. The most important urban characteristic separating warmer from cooler regions of the Portland metropolitan area was canopy cover. Roadway area density was also an important determinant of local UHI magnitudes. Specifically, the air above major arterial roads was found to be warmer on weekdays than weekends, possibly due to increased anthropogenic activity from the vehicle sector on weekdays. In general, warmer regions of the city were associated with industrial and commercial land-use. The downtown core, whilst warmer than the rural surroundings, was not the warmest part of the Portland metropolitan area. This is thought to be due in large part to local shading effects in the urban canyons. 相似文献
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The impact of weather variability on British outbound flows 总被引:1,自引:1,他引:0
Climate can be understood both as a resource and a motivation for tourism. This study focuses on the second issue trying to establish the sensitivity to weather anomalies of the outbound flows from United Kingdom, the third biggest international tourist spender country. Using transfer function models it is possible to analyze the significance of the short-term weather conditions in the determination of outbound British flows and simulate the effects of different climate change scenarios. Results show how mean temperature, heat waves, air frost and sunshine days are the weather variables that can be significantly related to the dynamics of the outbound British flows time series. 相似文献
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In this study, empirical orthogonal function was applied to analyze rainfall variability in the Nile basin based on various spatio-temporal scales. The co-occurrence of rainfall variability and the variation in selected climate indices was analyzed based on various spatio-temporal scales. From the highest to the lowest, the cumulative amount of variance explained by the first two principal components (PCs) for any selected size of the spatial domain was obtained for the annual, seasonal, and monthly rainfall series respectively. The variability in the annual rainfall of 1° × 1° spatial coverage explained by only the first PC was about 55% on average. However, this percentage reduced to about 40% on average across the study area when the size of the spatial domain was increased from 1° × 1° to 10° × 10°. The variation in climate indices was shown to explain rainfall variability more suitably at a regional than location-specific spatial scale. The magnitudes and sometimes signs of the correlation between rainfall variability and the variation in climate indices tended to vary from one time scale to another. These findings are vital in the selection of spatial and temporal scales for more considered attribution of rainfall variability across the study area. 相似文献
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Power spectral and cross-spectral studies of atmospheric electrical parameters for different months of the year are presented. The data represent fair weather conditions and the frequency range is from 0.01 to 0.3 cph. The analysis shows spectral peaks in the atmospheric electric parameters for frequencies corresponding to the diurnal wave; in many cases large variances are noted for the frequencies 0.083, 0.125 and 0.17 cph. Annual cycles in the spectra are also observed. In general, fairly small variances are obtained for frequencies above 0.05 cph. High coherences for the atmospheric electric parameters are observed in the lower frequency part of the spectra and in some cases in other parts as well (i.e., 0.083, 0.125 and 0.17 cph). Phase relationships of the electric components are also presented. 相似文献
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对2005—2008年辽宁省高速公路交通事故资料进行统计。结果表明:辽宁省高速公路发生交通事故呈逐年上升趋势,其中由天气原因及其所引起的不良路况所造成的交通事故占20.4%,5—8月和11—翌年1月是此类交通事故的两个多发期。在各类天气现象中,因雾引起的交通事故所占比例最高,为41.0%,雨次之为31.3%。在此基础上就如何做好高速公路气象服务提出四点措施:划分灾害性天气服务关键性路段和关键期,制定高速公路安全运营气象灾害防御地方标准,在高速公路沿线布设密度适宜的气象监测站,加强气象对高速公路影响机理的研究。 相似文献
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Hamdy K. Elminir 《Meteorology and Atmospheric Physics》2007,96(3-4):245-256
Summary Air pollution measurements from January 1999 to December 2003 were studied in 14 sites covering most of Egypt, with the aim
of understanding the governing processes pollutants phase interaction. The nature of the contributing sources has been investigated,
and some attempts have been made to indicate the role played by neighboring regions in determining the air quality at these
sites. The seasonal variability of particulate matter (PM10) and some gaseous pollutants (e.g., SO2, NO2, CO and O3) were analyzed. Their relationships with meteorology were also examined. The results reveal that levels of major air pollutants
were not significantly different at the rural and background sites during any season. On contrary the high atmospheric loading
for PM10, CO and SO2 was frequently observed in winter at the urban sites. As expected, the prevailing winds were found to have an influence not
only on air pollutants but also on the correlation between them. 相似文献
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The influence of micrometeorological parameters (wind speed, temperature stratification and atmospheric stability) upon electric polar conductivity, potential gradient, vertical total current density and vertical convection current density is studied by means of power spectral and coherence spectral analysis. The analyses show great variations in the atmospheric electric parameters for frequencies corresponding to the diurnal wave (0.042 cph) and in many cases great variances are noted for the frequencies 0.083, 0.125 and 0.17 cph. The influence of the micrometeorological parameters upon atmospheric electricity seems to be significant for these frequencies. Annual changes of the power and coherence spectra are also observed. 相似文献
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根据安顺供电对气象条件的需求,建立供电雷电监测系统,分析供电与气象要素之间的关系,提出对供电工程项目、安装维修有重大影响的气象指标。 相似文献
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Yu-Kyung Hyun S. K. Kar Kyung-Ja Ha J. H. Lee 《Theoretical and Applied Climatology》2010,102(1-2):43-60
The spatial and temporal variations in cloud-to-ground (CG) lightning and precipitation during the summer monsoon months in Korea have been analyzed in relation to the regional synoptic weather conditions. The lightning data used in this study were collected from a lightning detection network installed by the Korean Meteorological Administration, while the precipitation data were collected from 386 Automatic Weather Stations spread over the entire Korean Peninsula during 2000 to 2001. A distinctive morning peak of precipitation is observed over the midwest region of Korea. Along the east coast, little precipitation and CG flash counts are found. Despite the strong afternoon peaks of convective rainfall due to the high elevation over the southern inland region, the south coast shows nocturnal or early morning peaks, which represents a common oceanic pattern of flash counts. In 2000, the nighttime peak for lightning counts dominates over the southern area, while the afternoon peak was strong in the midland during the summer, mainly due to the northward transportation of moisture to the Korean Peninsula. Conversely, the strong afternoon peak for the southern region was confronted with early morning peaks in the midwestern region during 2001. The eastward transport of moisture has been analyzed and was considered to be dominant in 2001. The study of several warm and cold type fronts in 2000 and 2001 indicate that the warm type fronts in 2000 were associated with very little lightning, while the cold type fronts appeared to be responsible for the occurrence of abundant lightning in 2001, thereby, indicating that the warm and cold type fronts were representative of the local lightning distribution in the respective years. 相似文献
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Nicolas Barrier Anne-Marie Treguier Christophe Cassou Julie Deshayes 《Climate Dynamics》2013,41(5-6):1159-1171
Interannual variability of subtropical sea-surface-height (SSH) anomalies, estimated by satellite and tide-gauge data, is investigated in relation to wintertime daily North-Atlantic weather regimes. Sea-level anomalies can be viewed as proxies for the subtropical gyre intensity because of the intrinsic baroclinic structure of the circulation. Our results show that the strongest correlation between SSH and weather regimes is found with the so-called Atlantic-Ridge (AR) while no significant values are obtained for the other regimes, including those related to the North Atlantic Oscillation (NAO), known as the primary actor of the Atlantic dynamics. Wintertime AR events are characterized by anticyclonic wind anomalies off Europe leading to a northward shift of the climatological wind-stress curl. The latter affects subtropical SSH annual variability by altered Sverdrup balance and ocean Rossby wave dynamics propagating westward from the African coast towards the Caribbean. The use of a simple linear planetary geostrophic model allows to quantify those effects and confirms the primary importance of the winter season to explain the largest part of SSH interannual variability in the Atlantic subtropical gyre. Our results open new perspectives in the comprehension of North-Atlantic Ocean variability emphasizing the role of AR as a driver of interannual variability at least of comparable importance to NAO. 相似文献
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Influence of seasonality on glacier mass balance, and implications for palaeoclimate reconstructions
Climates inferred from former glacier geometries in some areas exhibit discrepancies with regional palaeoclimates predicted
by General Circulation Models (GCMs) and modelling of palaeoecological data, possibly as a consequence of their differing
treatments of climatic seasonality. Since glacier-based climate reconstructions potentially offer an important tool in the
calibration of GCMs, which themselves need validation if used to predict future climate scenarios, we attempt to resolve mismatches
between these techniques by (1) investigating the influence of seasonality on glacier mass balance, and (2) refining the methodology
used for the derivation of glacier-based palaeoclimates. Focussing on the Younger Dryas stadial glaciation of Scotland, northeast
Atlantic, we show that sea-ice amplified seasonality led to a significantly drier climate than has been suggested by glacier-based
interpretations. This was characterised by a relatively short ablation season and the survival of a more substantial winter
snowpack. We suggest that if palaeoglaciological studies were to account for changes in seasonal temperature and precipitation
variability, their results would agree more closely with the cold, arid, northeast Atlantic palaeoenvironment predicted by
atmospheric modelling and northwest European pollen studies, and would therefore provide more accurate constraints for GCM
calibration. 相似文献