Seasonal features of aerosol particles recorded in snow from Mt. Qomolangma (Everest) and their environmental implications

To assess the seasonality of aerosol deposition and anthropogenic effects on central Himalayas, a 1.85-m deep snow pit was dug on the northern slope of Mt. Qomolangma （Everest）. Based on the morphology and energy dispersive X-ray （EDX） signal, totally 1500 particles were classed into 7 groups： soot; aluminosilicates; fly ash; calcium sulfates; Ca/Mg carbonates; metal oxides; and biological particles and carbon fragments. The size distribution and number fractions of different particle groups exhibited distinct seasonal variations between non-monsoon and monsoon periods, which are clearly related to the differences in air mass pathways. Specifically, the relative abundance of soot in non-monsoon period （25%） was much higher than that in monsoon period （14%）, indicating Mt. Qomolangma region received more anthropogenic influence in non-monsoon than monsoon period.

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 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.

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.

RECENT 200 YEARS CLIMATIC AND ENVIRONMENTAL RECORDS FROM THE FAR EAST RONGBUK ICE CORE, MT. QOMOLANGMA (EVEREST)

During the Sino\|American Expedition to Mt. Qomolangma in May 1997, a 41m ice core was recovered from an elevation of 6500m from the northern branch firn basin of the Far East Rongbuk Glacier in Mt. Everest. The ice core was dated down to 1814 by counting δ 18 O peaks and referring to the variations of β activity and major ion concentrations. The average annual accumulation is 224mm (ice equivalent). Five cold periods and five warm periods have been reconstructed from the ice core for the last 200 years and the general tendency of climatic change is warming, which is agree with the temperature change in the Northern Hemisphere. Also the climatic records in Far East Rongbuk ice core has good agreement with that in the Guliya ice core. This indicates that the climatic changes are consistent in the northwestern and southern Qinghai—Tibetan Plateau, and the ranges of climatic changes are larger in southern Plateau than that in northwestern Plateau. Though the δ 18 O variations has some negatively correlation with precipitation amount for short time scale, these do not effect δ 18 O changes reflecting temperature for long time scale.

Climate change in Mt. Qomolangma region since 1971

Using monthly average, maximum, minimum air temperature and monthly precipitation data from 5 weather stations in Mt. Qomolangma region in China from 1971 to 2004, climatic linear trend, moving average, low-pass filter and accumulated variance analysis methods, the spatial and temporal patterns of the climatic change in this region were analyzed. The main findings can be summarized as follows： （1） There is obvious ascending tendency for the interannual change of air temperature in Mt. Qomolangma region and the ascending tendency of Tingri, the highest station, is the most significant. The rate of increasing air temperature is 0.234℃/decade in Mt. Qomolangma region, 0.302 ℃/decade in Tingxi. The air temperature increases more strongly in non-growing season. （2） Compared with China and the global average, the warming of Mt. Qomolangma region occurred early. The linear rates of temperature increase in Mt. Qomolangma region exceed those for China and the global average in the same period. This is attributed to the sensitivity of mountainous regions to climate change. （3） The southern and northern parts of Mt. Qomolangma region are quite different in precipitation changes. Stations in the northern part show increasing trends but are not statistically significant. Nyalam in the southern part shows a decreasing trend and the sudden decreasing of precipitation occurred in the early 1990s. （4） Compared with the previous studies, we find that the warming of Mt. Qomolangma high-elevation region is most significant in China in the same period. The highest automatic meteorological comprehensive observation station in the world set up at the base camp of Mt. Qomolangma with a height of 5032 m a.s.l will play an important role in monitoring the global climate change.

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.

Seasonal variations in heavy metals concentrations in Mt.Qomolangma Region snow

The concentrations of heavy metals Ba, Pb, Cu, Zn and Co in snow pit collected in September, 2005 from the accumulation area of the East Rongbuk Glacier （6523 m a.s.l.）, which lies on the northern slope of Mt. Qomolangma, were determined by inductively coupled plasma mass spectrometry （ICP-MS）. Concentrations （pg/ml） of heavy metals are Ba2-227, Co2.8-15.7, Cu10-120, Zn29-4948 and Pb14-142, respectively. The 5180 was determined by MAT-252. The time period of the snow pit spans from autumn 2005 to summer 2004. Seasonal variations of the concentrations and δ^18O are observed, of which Pb, Cu, Zn and Co are much lower in summer monsoon season than that in non summer monsoon season, suggesting that different sources of heavy metals contributed to the site. EFc （crustal enrichment factors） is Co3.6, Cu27, Pb33 and Zn180, respectively. Higher EFo values of Pb, Cu and Zn suggest that Pb, Cu especially Zn are mainly contributed by anthropogenic sources.

Hydrological Characteristics of the Rongbuk Glacier Catchment in Mt.Qomolangma Region in the Central Himalayas,China

From 8 April to 11 October in 2005, hydrological observation of the Rongbuk Glacier catchment was carried out in the Mr. Qomolangma （Everest） region in the central Himalayas, China. The results demonstrated that due to its large area with glacier lakes at the tongue of the Rongbuk Glacier, a large amount of stream flow was found at night, which indicates the strong storage characteristic of the Rongbuk Glacier catchment. There was a time lag ranging from 8 to 14 hours between daily discharge peaks and maximum melting （maximum temperature）. As melting went on the time lag got shorter. A high correlation was found between the hydrological process and daily temperature during the ablation period. The runoff from April to October was about 80% of the total in the observation period. Compared with the discharge data in 1959, the runoff in 2005 was much more, and the runoff in June, July and August increased by 69%, 35% and 14%, respectively. The rising of temperature is a major factor causing the increase in runoff. The discharges from precipitation and snow and ice melting are separated. The discharge induced by precipitation accounts for about 20% of the total runoff, while snow and ice melting for about 80%.

Pressure and Temperature Feasibility of NCEP/NCAR Reanalysis Data at Mt.Everest

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.

Preliminary Estimation of Moisture Exchange in Rongbuk Valley on the Northern Slope of Mt. Qomolangma

Using observed wind and water vapor data from June 2006,water vapor exchange between the Rongbuk Valley and its above atmosphere is estimated for the first time.The water vapor level shows a high value from 23-29 June and a low from 12-21 June,which co-incide with the South Asian summer monsoon (SASM) active and break stages,respectively.The water vapor can be strongly injected into the closed region of the Rongbuk Valley from the outside atmosphere,with an average strength of 0.4 g s-1 m-2 in June 2006,given that no evaporation occurred.The air moisture exchange proc-esses can be greatly affected by the SASM evolution through changes in local radiation forcing.

VEGETATION CHANGE IN THE MT.QOMOLANGMA NATURAL RESERVE FROM 1981 TO 2001

1 Introduction On 18 May 1989,the Mt.Qomolangma (Everest)Natural Reserve(abbr.MQNR)in Tibet Autonomous Region formally came into existence and it was listed as World Network of Biosphere Reserves(WNBR)in May 2005.The MQNR is a comprehensive reserve,which mainly protects alpine ecosystems,plateau natural landscapes,geological remains and Tibetan historical and cultural heritages.

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 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.

Mt. Qomolangma:A barometer for global climate change

After 34-year-long studies,scientists have further justified the Mt.Qomolongma (Mt. Everest) region is sen-

THE HEIGHT OF MT. QOMOLANGMA

Mt. Qomolangma is the loftiest mountain at the top of Himalayas;the mountain peak is shaped like a pyramid and penetrates directly into the sky offering a spectacular view.

The Mountain Summit Auspicious Clouds and Dreams—Recapping the Moment of the Olympic Torch Relay Leg at the Mt.Qomolangma

The Beijing leg of the 2008 Olympic torch relay be-gan in spring.Along with the citizens in other cities,we were longing for a distinctive and stun-ning torch relay in terms of the route and the many colorful cer-emonial activities. The unprecedented plan to ex-tend the torch relay to Mt. Qomolangma will surely attract at-tention from all over the world.

The Earth Summit Mission-2022:Successful ozone soundings contribute to source identification in the north Mt.Qomolangma region

As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde)at Mt.Qomolangma Base Camp(MQBC;86.85°E,28.14°N;5200 m),a location at an extremely high altitude.A total of ten sounding profiles were obtained between April 30 and May 06,2022,of which seven profiles were above35 km in altitude,with a maximum detection altitude up to 39.0 km.This study presents the temporal variation and vertical distributions of atmospheric temperature,humidity,and ozone during the MQBC campaign.The averaged ozone concentration was high(68.3 ppbv)at the surface and then increased smoothly until peaking(~110 ppbv)in the middle troposphere(approximately 10 km),and afterward,the ozone concentration increased rapidly from the upper troposphere to a maximum of~10 ppmv at~30 km.The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure,and transport from the southern flank of the Himalayas occurred during the campaign period.The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35km in altitude.The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder(MLS)onboard the Aura satellite and the Atmospheric Infrared Sounder(AIRS)onboard the Aqua satellite.

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.

Impacts of the Kuwait Oil Fires on the Mount Qomolangma Region

Mt. Qomolangma (also known as Mt. Everest), the world's highest mountain, is situated over the world＇s highest plateau, the Tibetan Plateau. Because of its height and because of its distance from industrialized areas, the environmental state of the Mt. Qonlolangma region can normally be considered 'undisturbed'. It is interesting to investigate how this “undisturbed” state has been changing with time and whether it has been influenced by large environmentally disruptive events such as the Kuwait oil fires of 1990 and 1991 (Small, 1991). In order to do this, river water samples were collected from the Rongpu River at Rongpu Temple Station in the summers of 1992 and 1993,as was done in 1975, and aerosol samples were collected in the summer of 1992 at the same station as was done in 1980. River water samples were analyzed using atomic absorption spectroscopy (AAS) at the Chinese Academy of Sciences. Aerosol samples were analyzed using proton-induced x-ray emission (PIXE) at the University of Fudan in Shanghai. The results show that the concentrations of chemical species in the river water at Rongpu Temple Station were much higher in the summer of 1992 than they were in 1975 and 1993, and the concentrations of atmospheric chemical species were much higher in 1992 than they were in 1980. The environment of the north slope of Mt.Qomolangma was therefore heavily polluted before and / or during the summer of 1992, possibly due to the Kuwait oil fires in 1990 and 1991.