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1.
Sebastian H. Mernild Bent Hasholt Birger U. Hansen Bjarne H. Jakobsen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):59-68
Geografisk Tidsskrift, Danish Journal of Geography 107(2):59–68, 2007 Meteorological stations have been in operation since 1993 at Sermilik (65°40'N, 38°10'W), Ammassalik Island, southeast Greenland. This note presents meteorological observations for the year 2005 from the two meteorological stations: Station Nunatak (515 m a.s.l.) and Station Coast (25 m a.s.l.). The year 2005 was dominated by a temporal break down of Station Nunatak and defect instrument recordings at both stations. Average yearly measurements at both meteorological stations: Station Nunatak (1994–2004) and Station Coast (1998–2005) are presented to illustrate the climatic variability within the Mittivakkat Glacier catchment, and further compared with simultaneous standard synoptic meteorological DMI station climate observations (1994–2004) at the town Tasiilaq (Ammassalik) in order to establish transfer functions (linear regressions) and describe the spatial variability of climate variables. 相似文献
2.
Sebastian H. Mernild Bent Hasholt Bjarne H. Jakobsen Birger U. Hansen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):153-161
Geografisk Tidsskrift, Danish Journal of Geography 108(1):153–161, 2008 Meteorological stations have been in operation since 1993 at the Sermilik Research Station (65°40′N, 38°10′W), Ammassalik Island, Southeast Greenland. This note presents meteorological observations for the calendar year 2006 from the two meteorological stations: Station Nunatak (515 m a.s.l.) and Station Coast (25 m a.s.l.). The year 2006 record is not complete due to a temporal break down of Station Coast (from end-of June through beginning of August). Special focus is given to ground temperature measurements at the meteorological Station Nunatak (1994–2006) 0.1 and 0.3 m below the surface. Data are presented to illustrate the intra- and inter-annual temperature variability and possible trends in the upper part of the soil. 相似文献
3.
Birger Ulf Hansen Niels Nielsen Ole Humlum Bent Hasholt 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):85-90
In october 1990 an automatic weather station was established at the Arctic Station (65° 15', 53°31'W), Qeqertarsuaq (Godhavn), Central West Greenland. The Station register parameters each 20 minutes, and the paramters have been described in an earlier paper in this journal by Nielsen et al.(1995). The present paper summarizes meteorological parameters during 1999. During a field campaign in 1999, woody remains from Salix glauca were found on a nunatak, 515 m. a.s.l. on the Mittivakkat Glacier, South East Greenland. Radio carbon dating determined the age of a wood sample to AD 640. Together with analyses of macroscopic botanical remains and insect rests in peaty material found nearby, these results indicate, that a warmer climate prevailed near the glacier around AD 600. These findings are in accordance with temperature records based on studies of ice cores from the Greenland Ice sheet. 相似文献
4.
Niels Nielsen Ole Humlum Birger Ulf Hansen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):155-158
An automatic meteorological station has been operating at the Arctic Station (69°15'N, 53°31'W) in West Greenland since 1990. This paper summarizes meteorological parameters during 2000 including snow and sea ice cover, ground temperatures and active layer development, and presents comments on the local permafrost thickness. 相似文献
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6.
基于Modis地表温度的青藏高原东部及其邻近地区气温估算(英文) 总被引：2，自引：1，他引：1
Climatic conditions are difficult to obtain in high mountain regions due to few meteorological stations and, if any, their poorly representative location designed for convenient operation. Fortunately, it has been shown that remote sensing data could be used to estimate near-surface air temperature (Ta) and other climatic conditions. This paper makes use of recorded meteorological data and MODIS data on land surface temperature (Ts) to estimate monthly mean air temperatures in the southeastern Tibetan Plateau and its neighboring areas. A total of 72 weather stations and 84 MODIS images for seven years (2001 to 2007) are used for analysis. Regression analysis and spatio-temporal analysis of monthly mean Ts vs. monthly mean Ta are carried out, showing that recorded Ta is closely related to MODIS Ts in the study region. The regression analysis of monthly mean Ts vs. Ta for every month of all stations shows that monthly mean Ts can be rather accurately used to estimate monthly mean Ta (R2 ranging from 0.62 to 0.90 and standard error between 2.25℃ and 3.23℃). Thirdly, the retrieved monthly mean Ta for the whole study area varies between 1.62℃ (in January, the coldest month) and 17.29℃ (in July, the warmest month), and for the warm season (May-September), it is from 13.1℃ to 17.29℃. Finally, the elevation of isotherms is higher in the central mountain ranges than in the outer margins; the 0℃ isotherm occurs at elevation of about 4500±500 m in October, dropping to 3500±500 m in January, and ascending back to 4500±500 m in May next year. This clearly shows that MODIS Ts data combining with observed data could be used to rather accurately estimate air temperature in mountain regions. 相似文献
7.
Analysis of sensible heat flux(Qh),latent heat flux(Qe),Richardson number(Ri),bulk transport coefficient(Cd) and katabatic winds are presented by using the meteorological data in the near surface layer from an automatic weather station(AWS) in Princess Elizabeth Land,East Antarctica ice sheet and the data of corresponding period at Zhongshan station in 2002.It shows that annual mean air temperature at LGB69 is-25.6°C,which is 16.4°C lower than that at Zhongshan,where the elevation is lower and located on the coast.The temperature lapse rate is about 1.0°C/110 m for the initial from coast to inland.The turbulence heat flux at LGB69 displays obvious seasonal variations with the average sensible heat flux-17.9 W/m2 and latent heat flux-0.9 W/m2.The intensity(Qh+Qe) of coolling source is-18.8 W/m2 meaning the snow surface layer obtains heat from atmosphere.The near surface atmosphere is near-neutral stratified with bulk transport coefficients(Cd) around 2.8×10-3,and it is near constant when the wind speed higher than 8 m/s.The speed and the frequency of easterly Katabatic winds at LGB69 were higher than that at Zhongshan Station. 相似文献
8.
MODIS-based estimation of air temperature of the Tibetan Plateau 总被引：1，自引：0，他引：1
The immense and towering Tibetan Plateau acts as a heating source and, thus, deeply shapes the climate of the Eurasian continent and even the whole world. However, due to the scarcity of meteorological observation stations and very limited climatic data, little is quantitatively known about the heating effect and temperature pattern of the Tibetan Plateau. This paper collected time series of MODIS land surface temperature （LST） data, together with meteorological data of 137 stations and ASTER GDEM data for 2001-2007, to estimate and map the spatial distribution of monthly mean air temperatures in the Tibetan Plateau and its neighboring areas. Time series analysis and both ordinary linear regression （OLS） and geographical weighted regression （GWR） of monthly mean air temperature （Ta） with monthly mean land surface temperature （Ts） were conducted. Regression analysis shows that recorded Ta is rather closely related to Ts, and that the GWR estimation with MODIS Ts and altitude as independent variables, has a much better result with adjusted R 2 〉 0.91 and RMSE = 1.13-1.53℃ than OLS estimation. For more than 80% of the stations, the Ta thus retrieved from Ts has residuals lower than 2℃. Analysis of the spatio-temporal pattern of retrieved Ta data showed that the mean temperature in July （the warmest month） at altitudes of 4500 m can reach 10℃. This may help explain why the highest timberline in the Northern Hemisphere is on the Tibetan Plateau. 相似文献
9.
中国城市扩展对气温观测的影响及其高估程度(英文) 总被引：3，自引：1，他引：2
Since the implementation of the reform and opening up policy in China in the late 1970s, some meteorological stations ’entered’ cities passively due to urban expansion. Changes in the surface and built environment around the stations have influenced observations of air temperature. When the observational data from urban stations are applied in the interpolation of national or regional scale air temperature dataset, they could lead to overestimation of regional air temperature and inaccurate assessment of warming. In this study, the underlying surface surrounding 756 meteorological stations across China was identified based on remote sensing images over a number of time intervals to distinguish the rural stations that ’entered’ into cities. Then, after removing the observational data from these stations which have been influenced by urban expansion, a dataset of background air temperatures was generated by interpolating the observational data from the remaining rural stations. The mean urban heat island effect intensity since 1970 was estimated by comparing the original observational records from urban stations with the background air temperature interpolated. The result shows that urban heat island effect does occur due to urban expansion, with a higher intensity in winter than in other seasons. Then the overestimation of regional air temperature is evaluated by comparing the two kinds of grid datasets of air temperature which are respectively interpolated by all stations’ and rural stations’ observational data. Spatially, the overestimation is relatively higher in eastern China than in the central part of China; however, both areas exhibit a much higher effect than is observed in western China. We concluded that in the last 40 years the mean temperature in China increased by about 1.58℃, of which about 0.01℃ was attributed to urban expansion, with a contribution of up to 0.09℃ in the core areas from the overestimation of air temperature. 相似文献
10.
利用中山站 1 989年建站以来和澳大利亚戴维斯站同期气象资料 ,分析了普里兹湾地区短期气候变化过程及其特征。结果表明 ,该地区温度变化存在明显的降温倾向 ,两站降温趋势均为 - 0 .0 66℃ /a ,其结果与整个南极地区温度变化趋势相反。降温倾向的主要特点是月平均温度以秋季下降幅度最大 ,夏季则为升温 ,最高温度存在升温倾向 ,最低温度呈现降温趋势。该地区月平均温度波动很大 ,极端异常过程中月平均温度偏高或偏低达到 1 0℃左右 ,与南极大陆地面高压和绕极低压中心位置及范围的异常分布关系密切。 相似文献
11.
A 70-year history of precipitation δ18O record has been retrieved using an ice core drilled from a plat portion of the firn area in the Guoqu Glacier (33o34′37.8″ N, 91o10′35.3″ E, 5720 m a.s.l.) on Mt. Geladaindong (the source region of Yangtze River) during October and November, 2005. Based on the seasonality of δ18O records and the significant positive relationships between monsoon/non-monsoon δ18O values and summer/spring air temperature from the nearby meteorological stations, the history of summer and spring air temperature have been reconstructed for the last 70 years. The results show that both summer and spring air temperature variations present similar trends during the last 70 years. Regression analysis indicates that the slope of the temperature-δ18O relationship is 1.3℃/‰ for non-monsoon δ18O values and spring air temperature, and 0.4℃/‰ for monsoon δ18O values and summer air temperature. Variation of air temperature recorded in the ice core is consistent with that in the Northern Hemisphere (NH), however, the warming trend in the Geladaindong region is more intense than that in the NH, reflecting a higher sensitivity to global warming in the high elevation regions. In addition, warming trend is greater in spring than in summer. 相似文献
12.
Sheng-I Hsu 《The Professional geographer》1984,36(2):196-200
Long-term minimum temperature records at climatic stations in the metropolitan Phoenix area present evidence of changes attributed to the urbanization process. The winter mean minimum temperature near the city's center has increased by 2° C from the agricultural period (1901–1920) to the modern period (1961–1977) and the difference of winter mean minimum temperatures between the center of the metropolitan region and the suburban area has increased from 3° C to 4° C during the same periods. 相似文献
13.
Birger Ulf Hansen Ole Humlum Niels Nielsen Dorte P. Lundqvist Ditte L. Jansen Christian Christiansen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):93-109
An automatic meteorological station has been operating at the Arctic Station (69°15'N, 53°31'W) in West Greenland since 1990. This paper summarises meteorological parameters during 2002, including snow cover, ground temperatures and active layer development, and air temperatures at the Station during the last 12 years are compared to large scale trends during the last century. A compilation of 93 sedimentation rate determinations based on 210Pb dating has been carried out for the North Sea-Baltic Sea transition area from a database containing 165 determinations carried out by Danish institutions. In the depositional parts of the area sedimentation rates generally range 25–6403 g m?2 y?1. An extreme rate of 13351 g m?2 y?1 is observed on a station in the Skagerrak. Sedimentation rates significantly increase with depth indicating that the Skagerrak and northern parts of the Kattegat as well as the deep basins in the Baltic Sea act as depocentres for fine-grained sediments. Apparently, sedimentation rates have increased in recent years. 相似文献
14.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):290-302
Two-years of ground temperatures (10 cm and 50 cm depths) from the foreland of Storbreen in the Jotunheimen Mountains of Norway demonstrate that seasonal and annual ground temperature differences induced by microtopographic position at a constant elevation are comparable to differences stemming from ～ 100 m to ～ 300 m in elevation. Between ～ 1460 m a.s.l. and ～ 1150 m a.s.l., mean annual lapse rates calculated for soil depths of 10 cm were≤0.8°C per100m beneath tundra, moraine crests, and moraine proximal base positions, each of which was calculated independently. Seasonal lapse rates were often larger,≥1.0°C per 100m in both summer and winter. The calculated ground temperature lapse rates compare favorably with those already reported in the literature for the region. Categorical data in the form of Thawed, Freeze-Thaw, Isothermal, and Frozen Days also showed considerable variability by elevation and microtopographic position. Variability in growing conditions was examined by calculating Thawing Degree Days and Growing Degree Days. These values sometimes, but not always, mimic ground temperature patterns. Although no wintertime field observations are available, the depth and duration of seasonal snow cover appears to be the primary source of variability. 相似文献
15.
The research of coupling WRF (Weather Research and Forecasting Model) with a land surface model is enhanced to explore the
interaction of the atmosphere and land surface; however, regional applicability of WRF model is questioned. In order to do the
validation of WRF model on simulating forcing data for the Heihe River Basin, daily meteorological observation data from 15 stations
of CMA (China Meteorological Administration) and hourly meteorological observation data from seven sites of WATER
(Watershed Airborne Telemetry Experimental Research) are used to compare with WRF simulations, with a time range of a whole
year for 2008. Results show that the average MBE (Mean Bias Error) of daily 2-m surface temperature, surface pressure, 2-m relative
humidity and 10-m wind speed were ?0.19 °C, ?4.49 hPa, 4.08% and 0.92 m/s, the average RMSE (Root Mean Square Error)
of them were 2.11 °C, 5.37 hPa, 9.55% and 1.73 m/s, and the average R (correlation coefficient) of them were 0.99, 0.98, 0.80 and
0.55, respectively. The average MBE of hourly 2-m surface temperature, surface pressure, 2-m relative humidity, 10-m wind speed,
downward shortwave radiation and downward longwave were ?0.16 °C, ?6.62 hPa, ?5.14%, 0.26 m/s, 33.0 W/m2 and ?6.44
W/m2, the average RMSE of them were 2.62 °C, 17.10 hPa, 20.71%, 2.46 m/s, 152.9 W/m2 and 53.5 W/m2, and the average R of
them were 0.96, 0.97, 0.70, 0.26, 0.91 and 0.60, respectively. Thus, the following conclusions were obtained: (1) regardless of
daily or hourly validation, WRF model simulations of 2-m surface temperature, surface pressure and relative humidity are more
reliable, especially for 2-m surface air temperature and surface pressure, the values of MBE were small and R were more than 0.96;
(2) the WRF simulating downward shortwave radiation was relatively good, the average R between WRF simulation and hourly
observation data was above 0.9, and the average R of downward longwave radiation was 0.6; (3) both wind speed and rainfall
simulated from WRF model did not agree well with observation data. 相似文献
16.
新疆北部夏季降水与海温异常的关系 总被引：1，自引：1，他引：0
利用1960—2004年新疆北部36个气象站月降水资料和美国国家气候数据中心重建的1960—2004年全球2°×2°月平均海洋表面温度资料,研究了新疆北部夏季降水与海温异常的关系。研究表明,新疆北部夏季降水变化与ENSO事件关系不密切,而与前期冬末—春季的5个海温敏感区密切联系,这5个海温敏感区分别为北印度洋、西太平洋暖池及黑潮区、热带中东太平洋、北大西洋和热带大西洋。前期春季海温异常与新疆北部夏季降水变化联系最显著,表现为显著正相关关系。研究为预测新疆北部夏季降水提供了有益的因子。 相似文献
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Due to the difficult logistics in the extreme high elevation regions over the Himalayas and Tibetan Plateau, the observational meteorological data are very few. In 2003, an automatic weather station was deployed at the northeastern saddle of Mt. Nyainqentanglha (NQ) (30°24′44.3″ N, 90°34′13.1″ E, 5850 m a.s.l.), the southern Tibetan Plateau. In 2005, another station was operated at the East Rongbuk Glacier Col (28°01′0.95″ N, 86°57′48.4″ E, 6523 m a.s.l.) of Mt. Qomolangma. Observational data from the two sites have been compared with the reanalysis data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR), reliability of NCEP/NCAR reanalysis data has been investigated in the Himalayas/Tibetan Plateau region. The reanalysis data can capture much of the synoptic-scale variability in temperature and pressure, although the reanalysis values are systematically lower than the observation. Furthermore, most of the variability magnitude is, to some degree, underestimated. In addition, the weather event extracted from the NCEP/NCAR reanalyzed pressure and temperature prominently appears one day ahead of the observational data on Mt. Qomolangma, while on Mt. NQ it occurs basically in the same day. 相似文献
20.
Ole Humlum Birger Ulf Hansen Niels Nielsen Hanne H. Christiansen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):113-121
An automatic meteorological station has been operating at the Arctic Station (69°15'N, 53°31'W) in West Greenland since 1990. This paper summarises meteorological parameters during 1998, including snow cover, ground temperatures and active layer development, and presents comments on the local permafrost thickness. Abstract Active layer monitoring in Greenland was started in 1996 and 1997, and forms part of the Circumpolar Active Layer Monitoring (CALM) Network of the International Permafrost Association (IPA). The results of the first years of this monitoring of thaw progression and maximum active layer thickness in two Greenlandic permafrost areas are presented. Two sites are in the continuous permafrost zone at Zackenberg in NE Greenland (74 °N), and one at Disko Island in W Greenland (69 °N), at the border between discontinuous and continuous permafrost. The data collected at Zackenberg demonstrate interannual variation in the timing of thaw progression in the monitoring grid holding a seasonal snowpatch, while there is less variation in the horizontal grid without a snowpatch. The maximum active layer thickness for the two Zackenberg grids is more or less consistent for the first three years with averages from 58 to 66 cm in mid and late August. At Disko the active layer reached 71 cm in mid August 1998. Spatially the distribution of the maximum, annual active layer thickness within the grids is concordant. 相似文献