Meteorological Features at 6523 m of Mt.Qomolangma(Everest)between 1 May and 22 July 2005

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 re-sultant 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. Qomo-langma. Here its meteorological characteristics were analyzed according to the 10-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 tem-perature, 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 hu-midity and air pressure increased with some dif-ferent 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 thepaper 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.

Acceleration of Glacier Mass Loss after 2013 at the Mt.Everest(Qomolangma)

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.

The Observed Low CO_2 Concentration in the Rongbuk Valley on the Northern Slope of Mt. Everest

In the summers of 2006 and 2007, the atmospheric CO 2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mt. Everest were measured by an ultrasonic anemometer with an Li-7500 CO 2 /H 2 O gas analyzer. The average CO 2 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 CO 2 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.

Vegetation change in the Mt. Qomolangma Nature Reserve from 1981 to 2001

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.

Glacial change in the vicinity of Mt. Qomolangma （Everest）, central high Himalayas since 1976

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.

Climatological significance of an ice core net-accumulation record at Mt. Qomolangma (Everest)

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.

Organochlorine pesticides in fresh-fallen snow on East Rongbuk Glacier of Mt.Qomolangma (Everest)

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.

Progress in technology for the 2005 height determination of Qomolangma Feng (Mt. Everest)

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.

Seasonal variation of snow microbial community structure in the East Rongbuk glacier, Mt. Everest

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.

近30年珠穆朗玛峰国家自然保护区冰川变化的遥感监测

利用1976、1988和2006年的3期陆地卫星遥感数据,采用面向对象的解译方法并结合专家知识分类规则自动提取珠穆朗玛峰国家自然保护区(以下简称珠峰保护区)3个时期的冰川信息,并利用遥感、地理信息系统和图谱的方法对冰川时空分布特征和变化及其原因与不确定性进行了分析。结果如下:(1)2006年珠峰保护区内冰川面积为2710.17±0.011km2,为研究区总面积的7.41%,主要分布在研究区南部海拔4700～6800m的高山区;(2)1976-2006年,珠峰保护区冰川持续退缩明显,总面积减少501.91±0.035km2,冰湖扩张迅速(净增加36.88±0.035km2);研究区南坡子流域冰川退缩率(16.79%)高于北坡子流域(14.40%);珠峰保护区冰川以退缩为主,退缩冰川主要分布于海拔4700～6400m,退缩区上限海拔为6600～6700m;(3)1976年以来,气温显著上升和降水减少是冰川退缩的关键因素。

珠峰北坡地区近地层大气湍流与地气能量交换特征

利用珠峰北坡曲宗地区连续一年的大气观测资料(2005年4月至2006年3月),分析了珠峰北坡地区近地层大气湍流宏观统计特征和西南季风爆发前后地气能量交换特征。研究表明在珠峰北坡地区Monin-Obukhov相似定律同样适用。拟合得到了珠峰北坡曲宗地区近地层无因次风速分量方差以及温度和湿度归一化标准差和静力学稳定度的函数关系。研究得出曲宗地区能量平衡各分量(净辐射通量、感热通量、潜热通量和土壤热通量)以及地面加热场具有明显的季节变化和日变化规律。尤其是在西南季风的影响下,曲宗地区感热通量和潜热通量在季风爆发前后具有明显相反的变化趋势。其它特征参数(波文比和地表反射率)在西南季风爆发前后的变化规律也十分明显。

珠穆朗玛峰地区新构造运动与环境地质灾害

研究区新构造运动强烈,环境地质灾害频繁,差异上升运动明显.除第四纪色龙盆地、定日盆地表现为相对下降外,其余均表现为上升,反映在环境地质灾害上,山洪、泥石流在雨季经常毁坏盆地内的公路。冰川后退形成的多达4级冰积埠阶地,佩枯错水面从67.9万年(P.B.)到12.6万年(P.B.)下降速率为0.021mm/a,从12.0万年(P.B.)到1.8万年(P.B.)下降速率为0.067mm/a,有加速下降的趋势,附近草地沙化严重,说明藏南面临十分严重的干旱形势,这可能与二氧化碳的过度排放、臭氧层变薄和温室效应等有关。雨季,第四纪盆地易发生洪流、泥石流等自然灾害;在珠穆朗玛峰和希夏邦马峰则容易产生雪崩。旅游、登山要避开7、8月份。

珠峰及邻近区域第四次大地测量

叙述了我国大地测量工作者于 1998年对珠穆朗玛峰及邻近区域进行的第四次大规模的大地测量外业概况和取得的成果 ,以及数据处理方法和最终结果。经过对 1998、196 6 - 196 8、1975、1992年珠峰及邻近区域四次大地测量数据综合分析 ,从地学方面进行研究 ,得出青藏块体在印度板块的推动下 ,仍向北东东方向运动 ;珠峰地区相对垂直运动在整体抬升的过程中伴有波浪式的起伏等结论。

在板块边缘的冲撞地区重力场的求定

在陆地上，板块边缘的冲撞地区一般都是呈现地形复杂、地表和地下的质量分布不均衡、有强烈的地壳运动和构造运动，因此，该地区的重力场（重力异常、垂线偏差、大地水准面）变化剧烈，对它的归算和推估都需要作特殊的考虑。本文以位于欧亚板块和印度板块边缘冲撞地区的珠穆朗玛峰测区的重力场求定为例，进行讨论。

2015年尼泊尔强震序列导致的喜马拉雅山峰位移场

基于2015年尼泊尔地震序列的破裂模型及均匀弹性半空间模型,计算了该地震序列导致的喜马拉雅山脉及邻区的位移场。结果表明:尼泊尔地震序列所导致的位移场呈南北两侧水平分量向震中会聚的分布形式,水平位移最大达871~962mm,并且距震中越远水平位移量越小,但震中南侧的水平位移量随震中距衰减更快。震中北侧出现了明显沉降,最大沉降量达376~474mm,大部分震中及以南区域出现了明显隆升,最大值达626~677mm。文中还估计了该地震序列导致的周围喜马拉雅山脉部分山峰的位移场,结果表明希夏邦马峰的位移最大,水平位移达393mm,下沉36mm;世界最高峰珠穆朗玛峰近S向水平移动36mm,下沉9mm;其他山峰的位移因与到尼泊尔地震序列的震中距离和方位的不同而不同。

以全球参照系为基准的珠峰地区重力场

珠穆朗玛峰位于欧亚板块和印度板块边缘的碰撞地带 ,地壳运动活跃 ,地形复杂。三十余年来 ,我国曾单独或与国外合作在珠穆朗玛峰及其北部毗邻地区进行了五次 (196 6、1975、1992、1998和 1999年 )大规模的大地测量工作 ,其中包括天文、重力、平面、高程和气象等测量工作。根据这些大地测量成果以全球参照系为基准 ,对该地区的重力场进行了研究。提出了适用于该地区的推估重力异常。

中国的珠峰高程测定

20世纪60年代以来,我国曾单独或与外国合作,在1966年、1975年、1992年、1998年、1999年和2005年对珠穆朗玛峰高程进行了6次测定,开展了大规模的大地测量外业作业、数据处理和科学研究。介绍了我国近40年来珠峰高程测定的成果和进展,其中重点介绍了最新的2005年我国对珠穆朗玛峰高程测定的进展。相对于以前的珠峰测高,2005年在珠峰以北地区的地面控制和珠峰高程测定中,采用了较大规模和精密的GPS三维定位技术,采用了雷达探测技术测定珠峰峰顶冰雪覆盖层的深度,提高了测量珠峰高程和探测峰顶冰雪覆盖层深度的精度和可靠性。由此测得珠峰峰顶雪面正高(海拔高)为8847.93m,珠峰峰顶岩面正高为8844.43m,珠峰峰顶相应点的冰雪层厚度为3.50m。

Feasibility Comparison of Reanalysis Data from NCEP-I and NCEP-II in the Himalayas

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 Co(28°01' 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 Mt.Everes 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-atmosphere-ocean interactions.The interpolation from both NCEP-I and NCEP-II daily minimum temperature and daily mean pressure can capture most synoptic-scale variability(r>0.82, n=83, p<0.001).However there is difference between NCEP-I and NCEP-II reanalysis data because of different mode 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 frompressure appear at the same day as those from the observation, and some events occur one day ahead, while most weather events interpolated from NCEP-I and NCEP-II temperature 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.

Drinking Water Quality in the Sagarmatha National Park, Nepal

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.

Microbial community structure in major habitats above 6000 m on Mount Everest

Bacterial abundance in surface snow between 6600 and 8000 m a.s.l. on the northern slope of Mt. Ev- erest was investigated by flow cytometry. Bacterial diversity in serac ice at 6000 m a.s.l., glacier melt- water at 6350 m, and surface snow at 6600 m a.s.l. was examined by constructing a 16S rRNA gene clone library. Bacterial abundance in snow was higher than that in the Antarctic but similar to other mountain regions in the world. Bacterial abundance in surface snow increased with altitude but showed no correlation with chemical parameters. Bacteria in the cryosphere on Mt. Everest were closely related to those isolated from soil, aquatic environments, plants, animals, humans and other frozen environ- ments. Bacterial community structures in major habitats above 6000 m were variable. The Cyto- phaga-Flavobacterium-Bacteroides (CFB) group absolutely dominated in glacial meltwater, while β-Proteobacteria and the CFB group dominated in serac ice, and β-Proteobacteria and Actinobacteria dominated in surface snow. The remarkable differences among the habitats were most likely due to the bacterial post-deposition changes during acclimation processes.