共查询到20条相似文献，搜索用时 250 毫秒
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Annett Wolf Eleanor Blyth Richard Harding Daniela Jacob Elke Keup-Thiel Holger Goettel Terry Callaghan 《Climatic change》2008,87(1-2):75-89
We tested the sensitivity of a dynamic ecosystem model (LPJ-GUESS) to the representation of soil moisture and soil temperature
and to uncertainties in the prediction of precipitation and air temperature. We linked the ecosystem model with an advanced
hydrological model (JULES) and used its soil moisture and soil temperature as input into the ecosystem model. We analysed
these sensitivities along a latitudinal gradient in northern Russia. Differences in soil temperature and soil moisture had
only little influence on the vegetation carbon fluxes, whereas the soil carbon fluxes were very sensitive to the JULES soil
estimations. The sensitivity changed with latitude, showing stronger influence in the more northern grid cell. The sensitivity
of modelled responses of both soil carbon fluxes and vegetation carbon fluxes to uncertainties in soil temperature were high,
as both soil and vegetation carbon fluxes were strongly impacted. In contrast, uncertainties in the estimation of the amount
of precipitation had little influence on the soil or vegetation carbon fluxes. The high sensitivity of soil respiration to
soil temperature and moisture suggests that we should strive for a better understanding and representation of soil processes
in ecosystem models to improve the reliability of predictions of future ecosystem changes. 相似文献
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Summary In this study the annual course of the air and sea-surface temperature in the Aegean sea is examined and a possibly existing relation between these two meteorological parameters is sought.To do this the monthly values of both elements for the period 1971–1975 were cross-correlated. It was found that in general the observed delay of the maximum and minimum values of the temperature of the sea was of the order of one month.With 1 Figure 相似文献
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作为档案管理人员，应随时随地掌握库内外温湿度的变化规律，以便及时采取措施调节库内温湿度，使档案材料有一个良好的保存环境，最大限度地延长档案材料的寿命。 相似文献
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Decadal Sahelian rainfall variability was mainly driven by sea surface temperatures (SSTs) during the twentieth century. At the same time SSTs showed a marked long-term global warming (GW) trend. Superimposed on this long-term trend decadal and multi-decadal variability patterns are observed like the Atlantic Multidecadal Oscillation (AMO) and the inter-decadal Pacific Oscillation (IPO). Using an atmospheric general circulation model we investigate the relative contribution of each component to the Sahelian precipitation variability. To take into account the uncertainty related to the use of different SST data sets, we perform the experiments using HadISST1 and ERSSTv3 reconstructed sets. The simulations show that all three SST signals have a significant impact over West Africa: the positive phases of the GW and the IPO lead to drought over the Sahel, while a positive AMO enhances Sahel rainfall. The tropical SST warming is the main cause for the GW impact on Sahel rainfall. Regarding the AMO, the pattern of anomalous precipitation is established by the SSTs in the Atlantic and Mediterranean basins. In turn, the tropical SST anomalies control the impact of the IPO component on West Africa. Our results suggest that the low-frequency evolution of Sahel rainfall can be interpreted as the competition of three factors: the effect of the GW, the AMO and the IPO. Following this interpretation, our results show that 50% of the SST-driven Sahel drought in the 1980s is explained by the change to a negative phase of the AMO, and that the GW contribution was 10%. In addition, the partial recovery of Sahel rainfall in recent years was mainly driven by the AMO. 相似文献
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T. Gustavsson 《Theoretical and Applied Climatology》1990,41(4):227-236
Summary The present study involves a discussion of nocturnal temperature variation due to topography and prevailing wind speed. It is part of the ongoing project Applied climatology for increased traffic safety and road maintenance, which aims at a development of a local climatological model applicable to winter road conditions. The temperature recordings which are used are from sensors in the Swedish Road Weather Information System in the county of Skaraborg.During clear and calm nights, local air temperature differences have been related to different topographical environments. The main factors resulting in large temperature differences are the effect of wind shelter, stagnation or production of cold air, and of cold air advection.Variation in air temperatures during clear and windy nights has also been studied. At wind speeds higher than 4–5 m/s, the temperature variation is low. With decreasing wind speed the variation in temperature increases, but only for sensor sites which have some wind shelter by topography or vegetation.The air temperature variation which develops during clear nights affects the road surface temperature. In this paper, the connection between road surface temperature differences and air temperature variation is discussed. A linear relationship between the two variables exists.With 5 Figures 相似文献
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从众多的地面温度观测记录来看，发现了很多地面最高温度表的记录和地面最低温度表的记录，分别比下午和上午地面0cm的值偏低和偏高许多，或者下午（上午）地面0cm温度表与地面最高温度表（地面最低温度表）读数相差较大的异常情况。以下就对这些情况出现的原因及处理方法提出一些看法和见解。 相似文献
9.
李发军 《高原山地气象研究》2002,22(3)
从众多的地面温度观测记录来看,发现了很多地面最高温度表的记录和地面最低温度表的记录,分别比下午和上午地面0cm的值偏低和偏高许多,或者下午(上午)地面0cm温度表与地面最高温度表(地面最低温度表)读数相差较大的异常情况.以下就对这些情况出现的原因及处理方法提出一些看法和见解: 相似文献
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Attribution of twentieth century temperature change to natural and anthropogenic causes 总被引：6，自引：0，他引：6
P. A. Stott S. F. B. Tett G. S. Jones M. R. Allen W. J. Ingram J. F. B. Mitchell 《Climate Dynamics》2001,17(1):1-21
We analyse possible causes of twentieth century near-surface temperature change. We use an “optimal detection” methodology
to compare seasonal and annual data from the coupled atmosphere-ocean general circulation model HadCM2 with observations averaged
over a range of spatial and temporal scales. The results indicate that the increases in temperature observed in the latter
half of the century have been caused by warming from anthropogenic increases in greenhouse gases offset by cooling from tropospheric
sulfate aerosols rather than natural variability, either internal or externally forced. We also find that greenhouse gases
are likely to have contributed significantly to the warming in the first half of the century. In addition, natural effects
may have contributed to this warming. Assuming one particular reconstruction of total solar irradiance to be correct implies,
when we take the seasonal cycle into account, that solar effects have contributed significantly to the warming observed in
the early part of the century, regardless of any relative error in the amplitudes of the anthropogenic forcings prescribed
in the model. However, this is not the case with an alternative reconstruction of total solar irradiance, based more on the
amplitude than the length of the solar cycle. We also find evidence for volcanic influences on twentieth century near-surface
temperatures. The signature of the eruption of Mount Pinatubo is detected using annual-mean data. We also find evidence for
a volcanic influence on warming in the first half of the century associated with a reduction in mid-century volcanism.
Received: 24 January 2000 / Accepted: 20 April 2000 相似文献
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自动站深层地温故障分析及解决办法 总被引：1，自引：0，他引：1
《气象研究与应用》2015,(2)
从深层地温实际案例出发,对一些常见的故障进行分析,找出解决办法,在最短时间内完成故障处理,提高数据的准确性和连续性。 相似文献
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P. Hignett 《Boundary-Layer Meteorology》1992,61(1-2):175-187
Methods of correcting the temperature output of a sonic anemometer-thermometer are examined. The errors in the temperature variance and flux are evaluated as a function of stability and examples given of correcting the sonic-derived temperature point by point. It is concluded that, in general, both humidity and crosswind corrections must be included. 相似文献
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Climate Dynamics - In this study, we carried out an attribution analysis that quantitatively assessed relative contributions to the observed temperature anomalies associated with strong and weak... 相似文献
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This paper deals with the most recent trends in meteorological and hydrological variables, which include air temperature and precipitation (P), potential and actual (ET) evapotranspiration, surface runoff (RO), water recharge into the soil (R) and water loss from the soil (L). Most hydrological variables were calculated via Palmer's algorithm. For this purpose, two rank-based statistical tests (the Mann?CKendall (MK) and a change-point analysis (CPA) approach) and the basic linear regression-based model were applied on the weekly precipitation and temperature from 17 stations all over Greece, during 1961?C2006. Only in winter, all variables except for R, which showed no clear signal, presented downward trends. The declining trends of P and L in spring and summer were counterbalanced by reductions in RO (and R in the case of summer) as opposed to increases in ET. In autumn, the declining tendencies of P and L were offset by RO reductions and R increases. Annually, the trends in water cycle components were analogous to that of spring, summer and autumn. The number of stations with statistically significant (at 95%) trends greatly varied with season and meteorological/hydrological variable. 相似文献
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1979-2012年中国探空温度资料中非均一性问题的检验与分析 总被引：1，自引：1，他引：0
利用加拿大环境部气候研究中心研发的PMTred(penalized maximum t test)非均一性检验方法,以ERA-interim资料作为参考序列,以中国各探空台站详细的元数据信息为主要断点判断依据,对1979-2012年中国125个探空台站7个标准等压面月平均探空温度资料进行了非均一性检验、订正,并结合详细的元数据信息分析了造成中国探空温度序列非均一问题的主要原因。研究表明,中国探空温度资料中存在由于人为因素造成的断点,整套探空资料中非均一的台站数和断点数所占的百分比呈低层少、高层多的趋势。各标准等压面上月平均温度序列非均一的探空台站平均订正幅度也随着高度的升高而增大,并且订正量为负值在整套订正资料中所占的比例较高,说明中国的探空月平均温度原始观测资料存在系统性偏高的问题。订正后200 hPa的温度变化趋势接近0,以200 hPa为转折点,100 hPa的降温趋势较订正前明显减弱,100 hPa以下为升温趋势,300-700 hPa的增温趋势加强。1979-2012年中国探空月平均温度资料的非均一问题主要来源于2000-2001年探测系统的升级(包括辐射误差订正方法的变化),其次是2002年之后观测仪器的换型。这两次连续的元数据变化均造成了之后中国探空月平均温度出现了系统性的降低,这也是造成订正前后温度变化趋势存在差异的主要原因。 相似文献