Mt. Qomolangma （Everest）, the highest mountain peak in the world, has little been studied extensively from a meteorological perspective, mostly because of the remoteness of the region and the resultant lack of meteo...Mt. Qomolangma （Everest）, the highest mountain peak in the world, has little been studied extensively from a meteorological perspective, mostly because of the remoteness of the region and the resultant lack of meteorological data. An automatic weather station （AWS）, the highest in the world, was set up on 27 April 2005 at the Ruopula Pass （6523 m asl） on the northern slope of Mt. Qomolangma by the team of integrated scientific expedition to Mt. Qomolangma. Here its meteorological characteristics were analyzed according to the lo-minute-averaged and 24-hour records of air temperature, relative humidity, air pressure and wind from 1 May to 22 July 2005. It is shown that at 6523 m of Mt. Qomolangma, these meteorological elements display very obvious diurnal variations, and the character of averaged diurnal variation is one-peak-and-one-vale for air temperature, one-vale for relative humidity, two-peak-and-two-vale for air pressure, and one-peak with day-night asymmetry for wind speed. In the 83 days, all the air temperature, relative humidity and air pressure increased with some different fluctuations, while wind speed decreased gradually and wind direction turned from north to south. The variations of relative humidity had great fluctuations and obvious local differences. Then the paper discusses the reason for the characters of diurnal and daily variations. Compared with the corresponding records in May 1960, 5-day-averaged maximums, minimums and diurnal variations of air temperature in May 2005 were apparently lower.展开更多
Mt.Everest (27°54' N,86°54' E),the highest peak,is often referred to as the earth's 'third' pole,at an elevation of 8844.43 m. Due to the difficult logistics in the extreme high elevation...Mt.Everest (27°54' N,86°54' E),the highest peak,is often referred to as the earth's 'third' pole,at an elevation of 8844.43 m. Due to the difficult logistics in the extreme high elevation regions over the Himalayas,observational meteorological data are very few on Mt. Everest. In 2005,an automatic weather station was operated at the East Rongbuk glacier Col of Mt. Everest over the Himalayas. The observational data have been compared with the reanalysis data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR),and the reliability of NCEP/NCAR reanalysis data has been investigated in the Himalayan region,after the reanalyzed data were interpolated in the horizontal to the location of Mt. Everest and in the vertical to the height of the observed sites. 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 variation extracted from the NCEP/NCAR reanalyzed pressure and temperature prominently appears one-day lead to that from the observational data,which is more important from the standpoint of improving the safety of climbers who attempt to climb Mt. Everest peak.展开更多
Satellite geodesy is capable of observing glacier height changes and most recent studies focus on the decadal scale due to limitations of data acquisition and precision.Glaciers at the Mt.Everest(Qomolangma),locating ...Satellite geodesy is capable of observing glacier height changes and most recent studies focus on the decadal scale due to limitations of data acquisition and precision.Glaciers at the Mt.Everest(Qomolangma),locating at the central Himalaya,have been studied from the 1970s to 2015.Here we obtained TerraSAR-X/TanDEM-X images observed in two epochs,a group around 2013 and another in 2017.Together with SRTM observed in 2000,we derived geodetic glacier mass balance between 2000 and 2013 and 2013 and 2017.We proposed two InSAR procedures for deriving the second period,which yields with basically identical results of geodetic glacier mass balance.The differencing between DEMs derived by TerraSAR-X/TanDEM-X shows better precision than that between TerraSAR-X/TanDEM-X formed DEM and SRTM,and it can capable of providing geodetic glacier mass balance at a sub-decadal scale.Glaciers at the Mt.Everest(Qomolangma)and its surroundings present obvious speeding up in mass loss rates before and after 2013 for both the Chinese and the Nepalese sides.The previous obtained spatial heterogeneous pattern for glacier downwasting between 2000 and 2013 generally kept the same after 2013.Glaciers with lacustrine terminus present the most rapid lost rates.展开更多
In the summers of 2006 and 2007, the atmospheric CO2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mr. Everest were measured by an ultrasonic anemometer with an Li-7500 CO2/H2O gas an...In the summers of 2006 and 2007, the atmospheric CO2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mr. Everest were measured by an ultrasonic anemometer with an Li-7500 CO2/H2O gas analyzer. The average CO2 concentration was 370.23±0.59 and 367.45±1.91 ppm in June of 2006 and 2007, respectively. The values are much lower than those at sites with similar latitudes and altitudes worldwide. The observed atmospheric CO2 concentration in Rongbuk Valley can be affected by the transportation of prevailing down-valley winds from the up-valley direction to the observation site. Our results suggest that the Mt. Everest region could be ideal for background atmospheric and environmental studies.展开更多
Based on the NOAA AVHRR-NDVI data from 1981 to 2001, the digitalized China Vegetation Map （1：1,000,000）, DEM, temperature and precipitation data, and field investigation, the spatial patterns and vertical character...Based on the NOAA AVHRR-NDVI data from 1981 to 2001, the digitalized China Vegetation Map （1：1,000,000）, DEM, temperature and precipitation data, and field investigation, the spatial patterns and vertical characteristics of natural vegetation changes and their influencing factors in the Mt. Qomolangma Nature Reserve have been studied. The results show that： （1） There is remarkable spatial difference of natural vegetation changes in the Mt. Qomolangma Nature Reserve and stability is the most common status. There are 5.04% of the whole area being seriously degraded, 13.19% slightly degraded, 26.39% slightly improved, 0.97% significantly improved and 54.41% keeping stable. The seriously and slightly degraded areas, which mostly lie in the south of the reserve, are along the national boundaries. The areas of improved vegetation lie in the north of the reserve and the south side of the Yarlung Zangbo River. The stable areas lie between the improved and degraded areas. Degradation decreases with elevation. （2） Degeneration in the Mt. Qomolangma Nature Reserve mostly affects shrubs, needle-leaved forests and mixed forests. （3） The temperature change affects the natural vegetation changes spatially while the integration of temperature changes, slopes and aspects affects the natural vegetation change along the altitude gradients. （4） It is the overuse of resources that leads to the vegetation degeneration in some parts of the Mt. Qomolangma Nature Reserve.展开更多
Glaciers are one of the most important land covers in alpine regions and especially sensitive to global climate change. Remote sensing has proved to be the best method of investigating the extent of glacial variations...Glaciers are one of the most important land covers in alpine regions and especially sensitive to global climate change. Remote sensing has proved to be the best method of investigating the extent of glacial variations in remote mountainous areas. Using Landsat thematic mapping （TM） and multi-spectral-scanner （MSS） images from Mt. Qomolangma （Everest） National Nature Preserve （QNNP）, central high Himalayas for 1976, 1988 and 2006 we derived glacial extent for these three periods. A combination of object-oriented image interpretation methods, expert knowledge rules and field surveys were employed. Results showed that （1） the glacial area in 2006 was 2710.17 ＋ 0.011 km2 （about 7.41% of the whole study area）, and located mainly to the south and between 4700 m to 6800 m above sea level; （2） from 1976 to 2006, glaciers reduced by 501.91± 0.035 km2 and glacial lakes expanded by 36.88 ＋ 0.035 kin2; the rate of glacier retreat was higher in sub-basins on the southern slopes （16.79%） of the Himalayas than on the northern slopes （14.40%）; most glaciers retreated, and mainly occurred at an elevation of 4700-6400 m, and the estimated upper limit of the retreat zone is between 6600 m and 6700 m; （3） increase in temperature and decrease in precipitation over the study period are the key factors driving retreat.展开更多
An ice core record at Mt. Qomolangma (Everest) since 1954 reveals a sharp decline in net-accumulation in the 1960s, and the annual net-accumulation during the 1970s to the beginning of the 1990s is only half of that a...An ice core record at Mt. Qomolangma (Everest) since 1954 reveals a sharp decline in net-accumulation in the 1960s, and the annual net-accumulation during the 1970s to the beginning of the 1990s is only half of that at the end of the 1950s. The decreased net-accumulation is coincident with glacier retreat, which is associated with recent temperature increase in the region that intensified the ablation. Under the background of global warming, such glacier variation trends will aggravate.展开更多
During a field campaign in April 2005,fresh-fallen snow samples were collected on the East Rongbuk Glacier of the Mt. Qomolangma at four altitudes (6500 m,6300 m,6100 m and 5900 m),to study the role of Mt. Qomolangma ...During a field campaign in April 2005,fresh-fallen snow samples were collected on the East Rongbuk Glacier of the Mt. Qomolangma at four altitudes (6500 m,6300 m,6100 m and 5900 m),to study the role of Mt. Qomolangma as "cold-traps" for Persistent Organic Pollutants. From these snow samples col-lected at the highest-altitude,organochlorine pesticides (OCPs):HCB,p,p′-DDT and p,p′-DDD were detected,with the concentrations in the ranges of 44―72 pg/L,401―1560 pg/L,and 20―80 pg/L,re-spectively. The concentration of o,p′-DDT was around the method detection limit. Analysis of backward trajectories showed that the detected compounds came from the north of India,suggesting that DDTs detected in the snow were possibly originated from new emissions in this area. Relationships between the concentrations of OCPs in snow samples and the sampling altitudes were discussed. The altitudes had no obvious effect on HCB concentrations in the fresh-fallen snow,while increases in the concen-trations of p,p′-DDT and p,p′-DDD with increasing altitude were found,which was reversed compared to the trends observed in North America. Three factors likely resulted in this trend: (1) the properties of the target compounds; (2) the low temperatures at high altitudes; and (3) the location of the mountain sampling sites relative to their sources.展开更多
In 2005 China carried out a new geodetic campaign for the height determination of Qo- molangma Feng——Mt. Everest (QF in short). The technical progresses in geodesy for the 2005 campaign are presented in the paper. G...In 2005 China carried out a new geodetic campaign for the height determination of Qo- molangma Feng——Mt. Everest (QF in short). The technical progresses in geodesy for the 2005 campaign are presented in the paper. GPS positioning was the key technique in the campaign. After summarizing the experiences and lessons of the GPS positioning on the QF summit in the previous QF height determination campaigns, some measures were taken to raise the accuracy and reliability of the height determination with GPS techniques. In order to raise the accuracy of the height deter- mination of the QF summit with classical geodetic techniques, laser ranging was used together with the trigonometric levelling in the 2005 campaign. It is the first time in China the thickness of the ice-snow layer on the QF summit was measured by ground penetrating radar integrated with GPS. The local gravity field and geoid in the QF area was improved on the basis of earth gravity field model integrated with new ground gravity data, DTM data and GPS leveling data in the QF area. In the 2005 campaign the normal height and orthometric height (height above sea level) of the snow surface of the QF summit were obtained as 8846.67 m and 8847.93 m respectively. The orthometric height of the rock surface of the QF summit is 8844.43 m,and the thickness of the ice-snow layer on the QF summit is 3.50 m.展开更多
The bacterial diversity and abundance in the snow of East Rongbuk glacier, Mt. Everest were examined through 16S rRNA gene clone library and flow cytometry approaches. In total, 35 16S rRNA gene sequences were obtaine...The bacterial diversity and abundance in the snow of East Rongbuk glacier, Mt. Everest were examined through 16S rRNA gene clone library and flow cytometry approaches. In total, 35 16S rRNA gene sequences were obtained, which belong to α, β, γ-Proteobacteria, Actinobacteria, Firmicutes, CFB, Cyanobacteria, Eukaryotic chloroplast, and TM7 candidate phylum respectively. γ-Proteobacteria was the dominant bacterial group in this region, while the genera Acinetobacter and Leclercia were domi- nant on the genus level. The community structure varied seasonally. The bacterial abundance in sum- mer snow was higher than that in winter. Moreover, the snow bacterial community structures in both seasons were diverse, with not only common species but season-specific species. The common species most likely originated from the Tibet Plateau. Bacteria in summer snow are affiliated with marine environ- ment, whereas bacteria in winter snow are closely related to more diverse environments and show the feature of resistance to cold. Seasonal variations of abundance and bacterial diversity were most proba- bly due to the seasonal characteristics of climate and atmospheric circulation in Mt. Everest.展开更多
Mt. Everest is often referred to as the earth＇s ＇third＇ pole. As such it is relatively inaccessible and little is known about its meteorology. In 2005, an automatic weather station was operated at North Col （28...Mt. Everest is often referred to as the earth＇s ＇third＇ pole. As such it is relatively inaccessible and little is known about its meteorology. In 2005, an automatic weather station was operated at North Col （28°1′ 0.95＂ N, 86°57′ 48.4＂ E, 6523 m a.s.l.） of Mt. Everest. Based on the observational data, this paper compares the reanalysis data from NCEP/NCAR （hereafter NCEP-Ⅰ） and NCEP-DOE AMIP-Ⅱ （NCEP- Ⅱ）, in order to understand which reanalysis data are more suitable for the high Himalayas with Mr. Everest region. When comparing with those from the other levels, pressure interpolated from 500 hPa level is closer to the observation and can capture more synoptic-scale variability, which may be due to the very complex topography around Mt. Everest and the intricately complicated orographic land-atmosphereocean interactions. The interpolation from both NCEP-Ⅰ and NCEP-Ⅱ daily minimum temperature and daily mean pressure can capture most synopticscale variability （r〉0.82, n=83, p〈0.001）. However, there is difference between NCEP-Ⅰ and NCEP-Ⅱ reanalysis data because of different model parameterization. Comparing with the observation, the magnitude of variability was underestimated by 34.1%, 28.5 % and 27.1% for NCEP-Ⅰ temperature and pressure, and NCEP-Ⅱ pressure, respectively, while overestimated by 44.5 % for NCEP-Ⅱ temperature. For weather events interpolated from the reanalyzed data, NCEP-Ⅰ and NCEP-Ⅱ show the same features that weather events interpolated from pressure appear at the same day as those from the observation, and some events occur one day ahead, while most weather events and NCEP-Ⅱ temperature interpolated from NCEP-Ⅰ happen one day ahead of those from the observation, which is much important for the study on meteorology and climate changes in the region, and is very valuable from the view of improving the safety of climbers who attempt to climb Mt. Everest.展开更多
In 2014 we began the first systematic study of water quality, specifically fecal contamination of drinking water in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region), Nepal. Our goal was to identif...In 2014 we began the first systematic study of water quality, specifically fecal contamination of drinking water in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region), Nepal. Our goal was to identify coliform bacteria and E. coli in drinking water and groundwater-fed springs to generate a data set that will function as a base for potable water supplies and further monitoring. Sampling occurred in May (pre-monsoon summer) and early November (post-monsoon early winter) 2014. Sample sites were selected based on proximity to villages and primary use as a drinking water source. Overall, the data presented a predictable correlation between fecal contamination and both elevation and increasing population/tourist traffic. Drinking water within the study area met current World Health Organization drinking water standards for the physical properties of temperature (2.8°C - 13°C), pH (5.27 - 7.24), conductivity (14.5 - 133 mS) and TDS (7.24 - 65.5 ppm). Samples from the more populated, lower altitude areas had higher levels of E. coli. Samples collected and analyzed in May (pre-monsoon summer) had a higher level of E. coli and coliform bacteria than samples collected in November (post-monsoon early winter) suggesting a seasonal dependence overlaid on the population signature. Surface water typically had higher E. coli values than groundwater-fed springs. Temperature, total dissolved solids and conductivity generally decreased with increasing elevation, whereas pH increased with increasing elevation. There appears to be significant presence of fecal contamination of water sources due to a combination of tourism, elevation and seasons.展开更多
基金partially funded by the National Nature Science Foundation of China(Grant No.40501015)the Chinese Academy of Science(Grant No.KZCX3-SW-354 and KZCX3-SW-344).
文摘Mt. Qomolangma （Everest）, the highest mountain peak in the world, has little been studied extensively from a meteorological perspective, mostly because of the remoteness of the region and the resultant lack of meteorological data. An automatic weather station （AWS）, the highest in the world, was set up on 27 April 2005 at the Ruopula Pass （6523 m asl） on the northern slope of Mt. Qomolangma by the team of integrated scientific expedition to Mt. Qomolangma. Here its meteorological characteristics were analyzed according to the lo-minute-averaged and 24-hour records of air temperature, relative humidity, air pressure and wind from 1 May to 22 July 2005. It is shown that at 6523 m of Mt. Qomolangma, these meteorological elements display very obvious diurnal variations, and the character of averaged diurnal variation is one-peak-and-one-vale for air temperature, one-vale for relative humidity, two-peak-and-two-vale for air pressure, and one-peak with day-night asymmetry for wind speed. In the 83 days, all the air temperature, relative humidity and air pressure increased with some different fluctuations, while wind speed decreased gradually and wind direction turned from north to south. The variations of relative humidity had great fluctuations and obvious local differences. Then the paper discusses the reason for the characters of diurnal and daily variations. Compared with the corresponding records in May 1960, 5-day-averaged maximums, minimums and diurnal variations of air temperature in May 2005 were apparently lower.
基金the Strategic Study Foundation of Chinese Polar Science （Grant No. 2007228） the National Nature Science Foundation of China （Grant No. 40501015） the Chinese Academy of Science （Grant No. KZCX3-SW-354 and KZCX3-SW-344）.
文摘Mt.Everest (27°54' N,86°54' E),the highest peak,is often referred to as the earth's 'third' pole,at an elevation of 8844.43 m. Due to the difficult logistics in the extreme high elevation regions over the Himalayas,observational meteorological data are very few on Mt. Everest. In 2005,an automatic weather station was operated at the East Rongbuk glacier Col of Mt. Everest over the Himalayas. The observational data have been compared with the reanalysis data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR),and the reliability of NCEP/NCAR reanalysis data has been investigated in the Himalayan region,after the reanalyzed data were interpolated in the horizontal to the location of Mt. Everest and in the vertical to the height of the observed sites. 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 variation extracted from the NCEP/NCAR reanalyzed pressure and temperature prominently appears one-day lead to that from the observational data,which is more important from the standpoint of improving the safety of climbers who attempt to climb Mt. Everest peak.
基金National Natural Science Foundation of China(No.41901384)National Basic Research Program of China(No.2015CB954103)+1 种基金General Research Fund of HKSAR(Nos.CUHK 14233016,CUHK 14206818)Open Foundation of State Key Laboratory of Geodesy and Earth’s Dynamics(No.SKLGED2018-2-3-EZ)。
文摘Satellite geodesy is capable of observing glacier height changes and most recent studies focus on the decadal scale due to limitations of data acquisition and precision.Glaciers at the Mt.Everest(Qomolangma),locating at the central Himalaya,have been studied from the 1970s to 2015.Here we obtained TerraSAR-X/TanDEM-X images observed in two epochs,a group around 2013 and another in 2017.Together with SRTM observed in 2000,we derived geodetic glacier mass balance between 2000 and 2013 and 2013 and 2017.We proposed two InSAR procedures for deriving the second period,which yields with basically identical results of geodetic glacier mass balance.The differencing between DEMs derived by TerraSAR-X/TanDEM-X shows better precision than that between TerraSAR-X/TanDEM-X formed DEM and SRTM,and it can capable of providing geodetic glacier mass balance at a sub-decadal scale.Glaciers at the Mt.Everest(Qomolangma)and its surroundings present obvious speeding up in mass loss rates before and after 2013 for both the Chinese and the Nepalese sides.The previous obtained spatial heterogeneous pattern for glacier downwasting between 2000 and 2013 generally kept the same after 2013.Glaciers with lacustrine terminus present the most rapid lost rates.
基金financed by the Chinese Academy of Sciences(Grant No.KZCX2-YW-Q11-01)the National Basic Research Program of China(Grant No.2009CB421403)
文摘In the summers of 2006 and 2007, the atmospheric CO2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mr. Everest were measured by an ultrasonic anemometer with an Li-7500 CO2/H2O gas analyzer. The average CO2 concentration was 370.23±0.59 and 367.45±1.91 ppm in June of 2006 and 2007, respectively. The values are much lower than those at sites with similar latitudes and altitudes worldwide. The observed atmospheric CO2 concentration in Rongbuk Valley can be affected by the transportation of prevailing down-valley winds from the up-valley direction to the observation site. Our results suggest that the Mt. Everest region could be ideal for background atmospheric and environmental studies.
基金the National Basic Research Program of China, No.2005CB422006Social Commonweal Re-search Project of Ministry of Science and Technology of China, No.2005DIA3J106National Natural Science Foundation of China, No.40331006
文摘Based on the NOAA AVHRR-NDVI data from 1981 to 2001, the digitalized China Vegetation Map （1：1,000,000）, DEM, temperature and precipitation data, and field investigation, the spatial patterns and vertical characteristics of natural vegetation changes and their influencing factors in the Mt. Qomolangma Nature Reserve have been studied. The results show that： （1） There is remarkable spatial difference of natural vegetation changes in the Mt. Qomolangma Nature Reserve and stability is the most common status. There are 5.04% of the whole area being seriously degraded, 13.19% slightly degraded, 26.39% slightly improved, 0.97% significantly improved and 54.41% keeping stable. The seriously and slightly degraded areas, which mostly lie in the south of the reserve, are along the national boundaries. The areas of improved vegetation lie in the north of the reserve and the south side of the Yarlung Zangbo River. The stable areas lie between the improved and degraded areas. Degradation decreases with elevation. （2） Degeneration in the Mt. Qomolangma Nature Reserve mostly affects shrubs, needle-leaved forests and mixed forests. （3） The temperature change affects the natural vegetation changes spatially while the integration of temperature changes, slopes and aspects affects the natural vegetation change along the altitude gradients. （4） It is the overuse of resources that leads to the vegetation degeneration in some parts of the Mt. Qomolangma Nature Reserve.
基金The External Cooperation Program of the Chinese Academy of Sciences,No.GJHZ0954National Basic Research Program of China,No.2005CB422006Institutional Consolidation for the Coordinated and Integrated Monitoring of Natural Resources towards Sustainable Development and Environmental Conservation in the Hindu Kush-Karakoram-Himalaya Mountain Complex
文摘Glaciers are one of the most important land covers in alpine regions and especially sensitive to global climate change. Remote sensing has proved to be the best method of investigating the extent of glacial variations in remote mountainous areas. Using Landsat thematic mapping （TM） and multi-spectral-scanner （MSS） images from Mt. Qomolangma （Everest） National Nature Preserve （QNNP）, central high Himalayas for 1976, 1988 and 2006 we derived glacial extent for these three periods. A combination of object-oriented image interpretation methods, expert knowledge rules and field surveys were employed. Results showed that （1） the glacial area in 2006 was 2710.17 ＋ 0.011 km2 （about 7.41% of the whole study area）, and located mainly to the south and between 4700 m to 6800 m above sea level; （2） from 1976 to 2006, glaciers reduced by 501.91± 0.035 km2 and glacial lakes expanded by 36.88 ＋ 0.035 kin2; the rate of glacier retreat was higher in sub-basins on the southern slopes （16.79%） of the Himalayas than on the northern slopes （14.40%）; most glaciers retreated, and mainly occurred at an elevation of 4700-6400 m, and the estimated upper limit of the retreat zone is between 6600 m and 6700 m; （3） increase in temperature and decrease in precipitation over the study period are the key factors driving retreat.
文摘An ice core record at Mt. Qomolangma (Everest) since 1954 reveals a sharp decline in net-accumulation in the 1960s, and the annual net-accumulation during the 1970s to the beginning of the 1990s is only half of that at the end of the 1950s. The decreased net-accumulation is coincident with glacier retreat, which is associated with recent temperature increase in the region that intensified the ablation. Under the background of global warming, such glacier variation trends will aggravate.
基金Supported by the National Outstanding Young Scholar Fund of the National Natural Science Foundation of China (Grant No.49925513)
文摘During a field campaign in April 2005,fresh-fallen snow samples were collected on the East Rongbuk Glacier of the Mt. Qomolangma at four altitudes (6500 m,6300 m,6100 m and 5900 m),to study the role of Mt. Qomolangma as "cold-traps" for Persistent Organic Pollutants. From these snow samples col-lected at the highest-altitude,organochlorine pesticides (OCPs):HCB,p,p′-DDT and p,p′-DDD were detected,with the concentrations in the ranges of 44―72 pg/L,401―1560 pg/L,and 20―80 pg/L,re-spectively. The concentration of o,p′-DDT was around the method detection limit. Analysis of backward trajectories showed that the detected compounds came from the north of India,suggesting that DDTs detected in the snow were possibly originated from new emissions in this area. Relationships between the concentrations of OCPs in snow samples and the sampling altitudes were discussed. The altitudes had no obvious effect on HCB concentrations in the fresh-fallen snow,while increases in the concen-trations of p,p′-DDT and p,p′-DDD with increasing altitude were found,which was reversed compared to the trends observed in North America. Three factors likely resulted in this trend: (1) the properties of the target compounds; (2) the low temperatures at high altitudes; and (3) the location of the mountain sampling sites relative to their sources.
文摘In 2005 China carried out a new geodetic campaign for the height determination of Qo- molangma Feng——Mt. Everest (QF in short). The technical progresses in geodesy for the 2005 campaign are presented in the paper. GPS positioning was the key technique in the campaign. After summarizing the experiences and lessons of the GPS positioning on the QF summit in the previous QF height determination campaigns, some measures were taken to raise the accuracy and reliability of the height determination with GPS techniques. In order to raise the accuracy of the height deter- mination of the QF summit with classical geodetic techniques, laser ranging was used together with the trigonometric levelling in the 2005 campaign. It is the first time in China the thickness of the ice-snow layer on the QF summit was measured by ground penetrating radar integrated with GPS. The local gravity field and geoid in the QF area was improved on the basis of earth gravity field model integrated with new ground gravity data, DTM data and GPS leveling data in the QF area. In the 2005 campaign the normal height and orthometric height (height above sea level) of the snow surface of the QF summit were obtained as 8846.67 m and 8847.93 m respectively. The orthometric height of the rock surface of the QF summit is 8844.43 m,and the thickness of the ice-snow layer on the QF summit is 3.50 m.
基金This work was supported by the Ministry of Science and Technology of the People's Republic of China(Grant No.2005CB422004)the National Natural Science Foundation of China(Grant Nos.40121101&40401054)the Innovation Program of the Chinese Academy of Sciences(Grant No.KZCX3-SW-339).
文摘The bacterial diversity and abundance in the snow of East Rongbuk glacier, Mt. Everest were examined through 16S rRNA gene clone library and flow cytometry approaches. In total, 35 16S rRNA gene sequences were obtained, which belong to α, β, γ-Proteobacteria, Actinobacteria, Firmicutes, CFB, Cyanobacteria, Eukaryotic chloroplast, and TM7 candidate phylum respectively. γ-Proteobacteria was the dominant bacterial group in this region, while the genera Acinetobacter and Leclercia were domi- nant on the genus level. The community structure varied seasonally. The bacterial abundance in sum- mer snow was higher than that in winter. Moreover, the snow bacterial community structures in both seasons were diverse, with not only common species but season-specific species. The common species most likely originated from the Tibet Plateau. Bacteria in summer snow are affiliated with marine environ- ment, whereas bacteria in winter snow are closely related to more diverse environments and show the feature of resistance to cold. Seasonal variations of abundance and bacterial diversity were most proba- bly due to the seasonal characteristics of climate and atmospheric circulation in Mt. Everest.
基金funded by the National Natural Science Foundation of China (Grant No. 40501015)the Chinese Academy of Science (Grant No. KZCX3-SW-344)
文摘Mt. Everest is often referred to as the earth＇s ＇third＇ pole. As such it is relatively inaccessible and little is known about its meteorology. In 2005, an automatic weather station was operated at North Col （28°1′ 0.95＂ N, 86°57′ 48.4＂ E, 6523 m a.s.l.） of Mt. Everest. Based on the observational data, this paper compares the reanalysis data from NCEP/NCAR （hereafter NCEP-Ⅰ） and NCEP-DOE AMIP-Ⅱ （NCEP- Ⅱ）, in order to understand which reanalysis data are more suitable for the high Himalayas with Mr. Everest region. When comparing with those from the other levels, pressure interpolated from 500 hPa level is closer to the observation and can capture more synoptic-scale variability, which may be due to the very complex topography around Mt. Everest and the intricately complicated orographic land-atmosphereocean interactions. The interpolation from both NCEP-Ⅰ and NCEP-Ⅱ daily minimum temperature and daily mean pressure can capture most synopticscale variability （r〉0.82, n=83, p〈0.001）. However, there is difference between NCEP-Ⅰ and NCEP-Ⅱ reanalysis data because of different model parameterization. Comparing with the observation, the magnitude of variability was underestimated by 34.1%, 28.5 % and 27.1% for NCEP-Ⅰ temperature and pressure, and NCEP-Ⅱ pressure, respectively, while overestimated by 44.5 % for NCEP-Ⅱ temperature. For weather events interpolated from the reanalyzed data, NCEP-Ⅰ and NCEP-Ⅱ show the same features that weather events interpolated from pressure appear at the same day as those from the observation, and some events occur one day ahead, while most weather events and NCEP-Ⅱ temperature interpolated from NCEP-Ⅰ happen one day ahead of those from the observation, which is much important for the study on meteorology and climate changes in the region, and is very valuable from the view of improving the safety of climbers who attempt to climb Mt. Everest.
文摘In 2014 we began the first systematic study of water quality, specifically fecal contamination of drinking water in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region), Nepal. Our goal was to identify coliform bacteria and E. coli in drinking water and groundwater-fed springs to generate a data set that will function as a base for potable water supplies and further monitoring. Sampling occurred in May (pre-monsoon summer) and early November (post-monsoon early winter) 2014. Sample sites were selected based on proximity to villages and primary use as a drinking water source. Overall, the data presented a predictable correlation between fecal contamination and both elevation and increasing population/tourist traffic. Drinking water within the study area met current World Health Organization drinking water standards for the physical properties of temperature (2.8°C - 13°C), pH (5.27 - 7.24), conductivity (14.5 - 133 mS) and TDS (7.24 - 65.5 ppm). Samples from the more populated, lower altitude areas had higher levels of E. coli. Samples collected and analyzed in May (pre-monsoon summer) had a higher level of E. coli and coliform bacteria than samples collected in November (post-monsoon early winter) suggesting a seasonal dependence overlaid on the population signature. Surface water typically had higher E. coli values than groundwater-fed springs. Temperature, total dissolved solids and conductivity generally decreased with increasing elevation, whereas pH increased with increasing elevation. There appears to be significant presence of fecal contamination of water sources due to a combination of tourism, elevation and seasons.
