Current Issue

• Observation of Diurnal Circulation on the Northern Slope of Mt. Qomolangma
• ZOU Han;ZHOU Li-bo;MA Shu-po;LI Peng;LI Ai-guo;HUO Cui-ping
• 2007 Vol. 26 (6): 1123-1140. 
• Abstract ( ) PDF (1628KB) ( )
• The energy/matter exchange between the surface air and the troposphere is the important connection of the Tibetan Plateau and the global atmospheric systems.The great imhomogeneity in the topography and surface cover of the Tibetan mountain systems induces complicated local atmospheric circulations,and the circulations influence the exchange processes between the surface air and the troposphere over these regions.To better understand the local circulations in the Tibetan mountains,authors conducted the observational campaign HEST2006,in the Rongbuk Valley on the northern slope of Mt.Qomolangma,during May 29 and June 30,2006.In this study,the diurnal atmospheric circulation is analyzed,using the observed data,including the distribution and variation of surface wind,the vertical structure,the vertical motion,and the possible driving forces.It results in that the local circulation in this region is driven by the solar radiative heating and cooling with strong impacts of the topography and surface covers,and the local circulation is composed of various mountain circulation systems.

• An Introduction to Atmospheric and Environmental Comprehensive Observation and Research Station on Mt. Qomolangma,Chinese Academy of Sciences(AECORSQ,CAS):A New Base for the Study of Atmosphere-Land Interaction over the Himalaya Area
• MA Yao-ming
• 2007 Vol. 26 (6): 1141-1145. 
• Abstract ( ) PDF (426KB) ( )
• The mountains of Himalayas are the important channels for the mass exchange between surface layer of Northern Hemisphere and troposphere atmosphere.The mountains relate surface layer atmosphere over the Tibetan Plateau and the above free atmosphere through many atmospheric circulation systems including mountain-valley wind and glacier wind etc.Mt.Qomolangma is the highest peak in the world,and its nearby region is a representative case of mountains of Himalayas.Firstly the back ground of the establishment of the Atmospheric and Environmental Comprehensive Observation and Research Station on Mt.Qomolangma,Chinese Academy of Sciences(AECORSQ,CAS) and the role of the station in the study of the atmosphere-land interaction over Himalayas area was introduced in this paper.Then the preliminary observational analysis results,such as the characteristics of air temperature,pressure,air humidity,wind speed and wind direction,the structure of the Atmospheric Boundary Layer(ABL),the atmospheric turbulent characteristics and the energy exchange between the land surface and surface layer atmosphere,were shown.The instruments layout of the AECORSQ,CAS was also given here.

• Simulation of Local Circulation in the Rongbuk Valley on the Northern Slope of Mt. Qomolangma
• ZHANG Mei-gen;MA Shu-po;XU Li-ren;LI Peng;ZOU Han;LI Ai-guo
• 2007 Vol. 26 (6): 1146-1150. 
• Abstract ( ) PDF (1059KB) ( )
• Field campaigns in the Rongbuk valley on the northern slope of Mt.Qomolangma found that surface flows in the valley exhibit strong diurnal variations,but differ much from other valley wind systems: Valley winds are less than 2 m·s^-1 from early morning to noon,while strong southerly winds from the direction of Mt.Qomolangma prevail from noon to mid-night.The distinctive feature of valley winds in the Rongbuk valley might be attributable to joint impacts of wind systems such as mountain-valley winds,katabatic winds and slope winds associated with complex topography and landuse on the northern slope of Mt.Qomolangma.In this paper a comprehensive mesoscale meteorological model is applied to simulate typical valley wind systems in the Rongbuk valley to investigate primary factors controlling the diurnal variations in surface valley winds,and model results are compared against in-situ observations.

• Turbulent Characteristics of the Surface Layer in Rongbuk Valley on the Northern Slope of Mt. Qomolangma
• LIU Hui-zhi;FENG Jian-wu;ZOU Han;LI Ai-guo
• 2007 Vol. 26 (6): 1151-1161. 
• Abstract ( ) PDF (1641KB) ( )
• Field campaigns were carried out in June 2007 in Rongbuk valley on north side of Mount Qomolangma over Tibetan Plateau.The turbulent data have been measured at 2 m and 8 m above ground,together with temperature,humidity measurements.The variations of turbulent statistics parameters,differences of wind speed and temperature between 2 m and 8 m have been investigated.Both spectrum and co-spectrum appear to follow Monin-Obukov similarity and Kolmogorov's prediction for the inertial subrange.The standard deviations of temperature and humility fluctuation support Monin-Obukov similarity theory.In neutral condition,relations between non-dimensional wind speed components and z/L follow "1/3 power law",and σ_u/u*=3.102,σ_v/u*=2.931,σ_w/u*=1.052.The coefficients are different from those in other places in Tibetan Plateau due to its special terrains.Unusual phenomena,such as that the latent heat flux measured at 2 m was always lower that that measured at 8 m in the valley,have been found in all day during the observation period.

• Characteristics and Analyses of Solar Radiation and Atmosphere on the Northern Slope of the Mount Qomolangma
• BAI Jian-hui;ZOU Han;LI Ai-guo;MA Shu-po;JIA Jing-jing;LI Peng;WANG Wei;HUO Cui-ping
• 2007 Vol. 26 (6): 1162-1172. 
• Abstract ( ) PDF (975KB) ( )
• Solar global radiation,net radiation,temperature,humidity,and wind were measured on the north slope of the Mount Qomolangma from May 27 to June 30,2006.3 stations were set up alone with the north slop of the Qomolangma,the measured radiation,temperature,wind showed an evident diurnal variation at 3 stations,and reached their daily maximums of changing rates at 08:00,09:00,respectively.Solar global and net radiation displayed similar diurnal pattern.For the beginning time of daily maximum,radiation is earlier than temperature,and temperature earlier than wind speed for all stations.The ratio of daily maximum of radiation including global and net radiation and the ratio of daily maximum of temperature and wind speed for any 2 stations were closer.For monthly averaged diurnal variation,wind direction in the region far away from the Qomolangma was changed several times during a day,but wind direction in the region near the Qomolangma wasn't changed,and was south wind all the time,which was caused by the difference of radiation,geological structure,air temperature,and etc.The change of wind(including direction and speed) alone valley on the north slop of the Qomolangma exhibited an obvious time lag,and south wind was stronger the north wind,and persisted longer time.Radiative energy plays an important driving role on the motion of the atmosphere on the north slop of the Qomolangma,and is the most basic and important factor to control and change the motion manner of the atmosphere.Net radiation plays a critical role in the processes of the changing of wind direction and speed at different regions.

• Impacts of the South Asian Summer Monsoon on Variations of Surface Wind on the Northern Slope of Mt. Qomolangma
• ZHOU Li-bo;ZOU Han;MA Shu-po;LI Peng;WU Rui-huan
• 2007 Vol. 26 (6): 1173-1186. 
• Abstract ( ) PDF (2007KB) ( )
• The Himalayas is near the South Asian monsoon region,with a special local circulation system induced by its steep topography and complex terrains.For better understanding the circulation system and its possible relationship with the weather pattern over the South Asian regions,we analyzed the variation of surface wind in the Rongbuk valley on the northern slope of Mt.Qomolangma and its responses to the South Asian summer monsoon(SASM),using the observation data obtained during HEST2006 campaign in June 2006 and real-time atmospheric circulation data.During the weak SASM period,the Himalayan regions are mainly dominated by clear days,and the northward surface wind prevails in the Rongbuk valley with a strong solar radiation;while during the strong SASM period,the surface wind and the solar radiation in the Rongbuk valley becomes weak,and the Himalayan regions are mainly controlled by the cloudy and rainy weather conditions.The analyszd result showed that the local circulation in the Rongbuk valley has little responses to the atmospheric circulation at the upper levels,but is closely related to the solar radiation flux and SASM index.Therefore,we concluded that the SASM could have impacts on the Himalayan surface circulation by changing the local thermal and radiation conditions.

• Characteristics of Local Circulation in a Himalayan Valley on the Northern Slop of Mt. Qomolangma
• SUN Fang-lin;MA Yao-ming
• 2007 Vol. 26 (6): 1187-1190. 
• Abstract ( ) PDF (406KB) ( )
• Using the observed data on an Atmospheric Boundary Layer(ABL) Tower located in the Atmospheric and Environmental Comprehensive Observation and Research Station on Mt.Qomolangma,Chinese Academy of Sciences(AECORSQ,CAS),in a Himalayan valley near Mt.Qomolangma during dry season,the characteristics of the diurnal variations in wind,air temperature,and humidity on 28 May 2006 are analyzed.The influence of slope wind and glacier wind on local circulation is found.The strong glacier wind occurs at afternoon,which brings temperature decrease.It can help understand that the air temperature reaches maximum when glacier wind occurs.The glacier wind also has influence on variation of air humidity.

• Analysis of Surface Wind in the Rongbuk Valley on the Northern Slope of Mt. Qomolangma
• ZHOU Li-bo;ZOU Han;MA Shu-po;LI Peng;WU Rui-huan
• 2007 Vol. 26 (6): 1191-1198. 
• Abstract ( ) PDF (1058KB) ( )
• Using the observation data obtained in the Rongbuk Valley in June 2007 and the real-time NCEP/NCAR reanalysis data,the variation of surface wind and its possible responses to the South Asian summer monsoon(SASM) were analyzed.There also exist strong and weak surface wind periods in 2007,however,which is not so clearly related to the SASM index as that in 2006.In the weak surface wind(strong SASM) period,the strong low pressure prevailed in the Bangladeshi Bay and Arabian Sea regions,which could bring the warm-wet air to the Rongbuk Valley and form high values there.However,the surface wind in the Rongbuk Valley has a little response to the variation of SASM in the strong wind period,which could be mainly driven by the local thermal and radiation processes.From the observation data obtained in 2006 and 2007,we think that the SASM could have impacts on the local circulation in the Rongbuk Valley through the changes of local thermal and radiation conditions,however,the impacts varied with the strength of monsoon.

• Observational Study on the Wind from Wind-Profiler during HEST2007
• ZOU Han;LI Peng;ZHU Jin-huan;MA Shu-po;LI Ai-guo
• 2007 Vol. 26 (6): 1199-1207. 
• Abstract ( ) PDF (1712KB) ( )
• To study the atmospheric circulations in the Himalayas,Institute of Atmospheric Physics and Institute of Tibetan Plateau Research,Chinese Academy of Sciences,held HEST2007 experiment in 2007 after the HEST2006 in 2006.This study is to analyze the diurnal and day-to-day variations of the local circulations in the Himalayas,observed by LAP-3000 wind-profiler system in the Rongbuk Valley on the northern slope of Mt.Qomolangma.The study shows the close relation between the axial winds in the valley and the west wind circulation.This relation can be attributed to the impacts of surface radiation situation changes caused by the synoptic system changes on the local circulation.

• Numerical Simulation of Atmospheric Boundary Layer Structure over Rongbuk Valley of Mt. Qomolangma
• ZHU Ling-yun;ZHANG Mei-gen;MA Shu-po;LI Peng;ZOU Han;LI Ai-guo
• 2007 Vol. 26 (6): 1208-1213. 
• Abstract ( ) PDF (792KB) ( )
• The Regional Atmospheric Modeling System(RAMS) was used to simulate the atmospheric boundary layer structure over Rongbuk valley of Mt.Qomolangma from 6 to 12 June 2006,and the simulated results agree well with the observations obtained by LAP3000 of the same period.The result shows that the local circulation has obvious diurnal variations on Rongbuk valley,the mountain wind dominates from noon to midnight,lasting almost 12 hours a day with strong wind velocity,and the mountain wind's vertical thickness is up to 400～700 m during the period of mountain wind dominating.The along-valley temperature gradient induced by heterogeneous land surface produces the local circulation.RAMS can reveal the temporal and spatial distributions of the local circulation over the Rongbuk valley.

• Simulation of the Effects of Glacier Cover on Local Circulation in the Rongbuk Valley
• MA Shu-Po;ZHOU Li-bo;ZOU Han;ZHANG Mei-gen
• 2007 Vol. 26 (6): 1214-1223. 
• Abstract ( ) PDF (1797KB) ( )
• The strong southerly valley winds prevail in the Rongbuk Valley on the northern slope of Mt.Qomolangma from noon to mid-night,which is different from diurnal mountain-valley wind in other mountains.In this paper,we use RAMS model to simulate the local wind in Rongbuk Valley,and the control experiment shows that RAMS can reproduce the strong predominating southerly wind in the Rongbuk Valley.To study the effects of glacier/snow cover on the local wind,we run a removing glacier/snow cover numerical simulation.The sensitivity experiment shows even though the glacier/snow vegetation has been substituted with bare ground,southerly wind can still develop in the valley from late afternoon(17:00 BJT).So glacier/snow cover play a very important role in the local wind in Rongbuk Valley,and thermally driven valley wind in the south slope of Mt.Qomolangma is the main factor to maintain the southerly wind in Rongbuk Valley from late afternoon to night.

• Observational Analysis of Atmospheric Mass Exchange in the Rongbuk Valley on the Northern Slope of Mt. Qomolangma
• MA Shu-po;ZHOU Li-bo;ZOU Han
• 2007 Vol. 26 (6): 1224-1230. 
• Abstract ( ) PDF (813KB) ( )
• Date of the LAP-3000 Wind Profiler set in the Rongbuk Valley on the northern slope of Mt.Qomolangma in June 2006 are analyzed to estimate the volume(or mass) flux in the valley cross section.Volume fluxes of the strong wind periods(9~21 June),weak wind periods(22~30 June) and the averaged periods of June(1~30 June) are calculated respectively.The results show that the diurnal averaged volume flux of the 3 periods are different,i.e.,the averaged total volume flux in the valley are positive all the time both in June and strong wind period,while in the weak wind period,it has a small negative value in the morning.Generally speaking,the volume flux of the predominating complex katabatic flow in the valley is very large.For example,the averaged daily total volume flux in June is 6.3×10¹¹m³,what more,the averaged daily total volume flux is much less in the weak wind period than in the strong wind period,and the former is about 53% of the latter.

• Determinating the Regional Distributions of Surface Heat Fluxes over Heterogeneous Landscape of Mt. Qomolangma Area Using the Satellite Remote Sensing and Field Observations
• MA Yao-ming;WANG Yong-jie;MA Wei-qiang;ZHONG Lei;SU Zhong-bo
• 2007 Vol. 26 (6): 1231-1236. 
• Abstract ( ) PDF (367KB) ( )
• The land surface over Mt.Qomolangma area is very heterogeneous.There are glacier,snow mountains,grassland,exposed mountains and Gobi desert etc.over this area.It is a very difficult issue to determine the regional land surface heat fluxes for the researchers for many years.In this study,a parameterization methodology based on satellite remote sensing data and field observations has been proposed for the determination of the regional distribution of surface parameters(surface reflectance and surface temperature),vegetation index(Normalized Difference Vegetation Index-NDVI,Modified Soil Adjusted Vegetation Index-MSAVI,vegetation fractional cover Pv and Leaf Area Index-LAI) and land surface heat fluxes(net radiation fluxes,soil heat fluxes,sensible heat flux and latent heat flux).The advantage and the shortcoming of the methodology were also discussed.

• Seasonal Variations of Land Surface Radiation Budget and Energy on Northern Slope of Mt. Qomolangma Area
• MA Wei-qiang;DAI You-xue;MA Yao-ming;SUN Fang-lin;LI Mao-shan;ZHONG Lei;WANG Jie-min
• 2007 Vol. 26 (6): 1237-1243. 
• Abstract ( ) PDF (833KB) ( )
• It is very important to study the regional heat fluxes in Mt.Qomolangma area.Using the data of Mt.Qomolangma site,the land surface heat fluxes are analyzed.Those are the net radiation flux(R_n),sensible heat fluxes(H),latent heat fluxes(λE) and soil heat fluxes(G₀).Some new results are gotten about surface energy fluxes in Mt.Qomolangma Area.The annual variations of downward short wave radiation,downward long wave radiation,upward short wave radiation,and net radiation were very obvious.The daily variations of net radiation flux,sensible heat flux,latent heat flux and soil heat flux were also obvious. Finally few ways of calculating surface heat fluxes are talked.

• Characteristics of Micrometeorological Elements and Turbulent Fluxes in the Surface Layer in Rongbuk Valley on Northern Slop of Mount Qomolangma
• FENG Jian-wu;LIU Hui-zhi;ZOU Han;LI Ai-guo
• 2007 Vol. 26 (6): 1244-1253. 
• Abstract ( ) PDF (1496KB) ( )
• Mount Qomolangma is a typical area with special land-surface atmosphere interaction over Tibetan Plateau,due to its high elevation and complicated terrain.The process can be better understood by observing the interaction itself and analyzing the variation of atmospheric elements and turbulent fluxes.Based on the turbulent data obtained in Rongbuk valley on northern slop of Mount Qomolangma during June 2006 and June 2007,the diurnal variation of micrometeorological elements and turbulent fluxes are investigated by using eddy covariance method.Results show that the diurnal cycles of micrometeorological elements and turbulent fluxes,such as wind,temperature,humility,sensible heat flux,latent heat flux etc.,are evident.Glacier wind blowing from noon to midnight are observed in this area.They play an important role in the mass and energy exchanges in the land-surface process of Rongbuk valley.

• Vertical Temperature Observation in the Rougbuk Valley on the Northern Slope of Mt. Qomolangma
• LI Peng;LI Ai-guo;JIA Jing-jing;ZOU Han
• 2007 Vol. 26 (6): 1254-1262. 
• Abstract ( ) PDF (1066KB) ( )
• The Qinghai-Xizang Plateau and its unique dynamic thermal effect influences the East Asian region as well as global weather,climate and environmental change process.Steep terrain and diverse state of the surface cause the complex circulation system and the boundary layer characteristics.During May 28 to June 30,2007,the Institute of Atmospheric Physics and the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences organized and implied the tropospheric atmosphere exchange research(HEST2007) on North Slope region in the Himalayas surface observation experiments to Study the local atmosphere circulation system of the mountains on the Qinghai-Xizang Plateau.In this Study,the virtual temperature obtained from LAP-3000 is converted to temperature,by using other observed data,and the vertical distribution of temperature and its changes are preliminary analyzed.The analysis shows the obvious differences is existed between the virtual temperature and the real temperature,the differences can be effectively decreased through the inversion,the vertical distribution of temperature is significantly different between the morning and afternoon in the Rougbuk valley.

• Characteristics of Micrometeorological Elements Near Surface and Soil on the Northern Slop of Mt. Qomolanma Area
• LI Mao-shan;MA Yao-ming;Hirohiko Ishikawa;MA Wei-qiang;SUN Fang-lin;WANG Yong-jie;ZHU Zhi-kun
• 2007 Vol. 26 (6): 1263-1268. 
• Abstract ( ) PDF (784KB) ( )
• Using the Planet Boundary Layer(PBL) observation data from September 2005 to August 2006,the characteristics of micrometeorological and soil were primarily analyzed on Mt.Qomolangma area.The results show that there was different monthly variation of micrometeorological and soil ones from other place on the Tibetan Plateau.The air temperature was lowest on December,while was highest on July.The soil freeze time was shorter on Mt.Qomolangma area than that on northern Tibetan Plateau.

• Variation Characteristics of Meteorological Elements,Radiation and Energy Budget Components before and after the Rainy Season in the Surface Layer of Mt. Qomolangma Area
• ZHONG Lei;MA Yao-ming;SU Z.(Bob);WANG Yong-jie;Lü Ya-qiong;ZHU Zhi-kun
• 2007 Vol. 26 (6): 1269-1275. 
• Abstract ( ) PDF (890KB) ( )
• Based on an eddy covariance measurement system set up at 4475 m on the northern slope of Mt.Qomolangma area,consecutive observation of atmospheric condition in Quzong was conducted.The variation characteristics of meteorological elements,radiation and energy budget components during the before rainy season(May),in rainy season(July) and after rainy season(November) season are analyzed.The results show that the diurnal mean variation of air temperature and relative humidity has one-peak-one-vale pattern.However,the diurnal mean variation is two-peak-two-vale for air pressure and one-peak pattern for wind speed.The wind speed always increases greatly in the afternoon.With the onset of Southwest monsoon,the air temperature,relative humidity,air pressure increase together with the decreasing of wind speed.The main wind direction changed from Northeast(NE) to Southwest(SW).In the before and after rainy season,there are also some clear variation trends for radiation and energy budget components.

• Water Environmental Evolution on the Northern Slop of Mt. Qomolangma since 1975
• GAO Yong-qi;GAO Deng-yi
• 2007 Vol. 26 (6): 1276-1279. 
• Abstract ( ) PDF (362KB) ( )
• Tibet Qomolangma has been for long time considered as an environment-clean place since its altitude and being far-away from modern industry.Here,we analyze the multi-year in-situ data from the river water samples in the Tibet Qomolangma.The results confirm the abrupt local environmental change in 1992 which is suggested by early study as an impact of the Kuwait Oil Fire in 1991-1992.Furthermore,the local environment is getting worse from 2004 to 2006 and the possible reason is explored.

• The Rainy Season Character of Troposphere at Mt. Qomolangma Region
• CHEN Xue-long;MA Yao-ming;SUN Fang-lin;LI Mao-shan;WANG Shu-zhou
• 2007 Vol. 26 (6): 1280-1286. 
• Abstract ( ) PDF (903KB) ( )
• Using the data of Atmospheric Boundary Layer(ABL) tower,radio sonde and wind profiler set up on the Comprehensive Observation and Research Station of Qomolangma,Chinese Academy of Sciences,lower layer atmosphere characteristics(wind speed,wind direction,air temperature,potential temperature and air humidity etc.) during the rain season were analyzed in this paper.Wind speed,wind direction and temperature near surface have obvious diurnal variations.For the wind direction,it is divided into two phase,one blow nearly north wind derived by Valley wind,the other blow nearly south wind derived by Glacier wind.The change time is 14:30.The diurnal Glacier wind is stronger than the nightly valley wind.Maybe vertical shear of horizontal wind is one important reason for precipitation in this region.The low level jet is familiar during summer.Averaged temperature digression of troposphere is 0.685K/100m.The vapor content in the air of lower atmosphere has two peak,the maximal vapor content height is blow 4000 m,the next peak is not fix.The relative humidity up than 16000 m cannot exceed 10%.Each layer has different wind speeds and directions.

• The Effect of Tibetan Plateau Heating on the East Asian Summer Precipitation
• LIU Xin;LI Wei-ping;HSU Huang-hsiung;WU Guo-xiong
• 2007 Vol. 26 (6): 1287-1292. 
• Abstract ( ) PDF (855KB) ( )
• The feature of East Asian summer precipitation pattern is an important character of Asian summer monsoon.Using the NCEP/NCAR reanalysis data and CRU precipitation data,this study reveals the effect of the Tibetan Plateau(TP) heating on the East Asian summer rainfall.Result shows the close correspondence between TP diabatic heating and East Asian simmer rainfall pattern.The TP heating fluctuation is associated with a Rossby wavelike circulation pattern on the coast area of East Asia.The Rossby wavelike pattern in turn affects and modifies the Northwest Pacific anticyclone,the result causes the variation of East Asian rainfall pattern.Because of the persistent TP diabatic heating from spring to summer and its effect on the surrounding areas,the TP heating index defined in this study can be used as a good predictor for the summer East Asian precipitation distribution.In this work,evidences shown the SST is not an only dominate external condition but also to consider other factor for understanding Asian summer monsoon.

• Study on Autumn Land Surface Fluxes over Complex Terrain Using Satellite Remote Sensing Data over the Mt. Qomolangma Region
• TIAN Hui;MA Yao-ming;WEN Jun;LI Mao-shan;SUN Fang-ling;MA Wei-qiang
• 2007 Vol. 26 (6): 1293-1299. 
• Abstract ( ) PDF (1137KB) ( )
• On the basis of the existing ripe remote sensing parameterization scheme of land surface energy fluxes,this study tries mapping the spatial distribution of autumn land surface fluxes over the vast southern Tibetan Plateau encompassing the Qomolangma region by combining MODIS data with the gradient data of surface layer atmosphere observed in the Qomolangma region from September to October of 2006.The result reveals that the land surface net radiation has a maximum value of 420.0 W·m^-2 or so,mainly in the range from 200.0 to 620.0 W·m^-2;the soil heat flux has a peak value of 110.0 W·m^-2 or so,mainly in the range from 50.0 to 180.0 W·m^-2;the sensible heat flux has a maximum value of 270.0 W·m^-2 or so,mainly in the range from 120.0 to 280.0 W·m^-2;and the latent heat flux has a peak value of 90.0 W·m^-2 or so,mainly in the range from 0.0 to 250.0 W·m^-2.Thus it is concluded that Autumn of in post-plateau monsoon,the daytime land surface heating field in the region assumes the principal form of the sensible heat to heat the atmosphere while the loss of energy consumed in the exchange of water between the land-surface and atmosphere is the minor term of the land surface energy balance.

• Diurnal and Seasonal Variations of the Carbon Dioxide over the Alpine Meadow Ecosystem on the Northern Slope of the Qomolangma
• ZHU Zhi-kun;MA Yao-ming;LI Mao-shan;ZHONG Lei
• 2007 Vol. 26 (6): 1300-1304. 
• Abstract ( ) PDF (339KB) ( )
• Based on the open-path eddy covariance observation over an alpine meadow ecosystem during growing season(from May to July,October November in 2005)and non-growing season(February March in 2006) at Quzong station(30°46'N,90°59'E,4730 m a.s.l) which is located on the northern side of the Qomolangma,the diurnal and seasonal variations of the carbon dioxide flux are analyzed in this paper.CO₂ flux dynamics was distinct between the two seasons.During the growing season the negative CO₂(CO₂ uptake)flux was observed from 08:00 to 19:00,but positive CO₂ flux(net CO₂ emission) from 20:00 to 09:00.In June,the maximum CO₂ uptake velocity was 0.61 g·m^-2·h^-1 which appeared at 11:00.In July,this value reached 0.86 g·m^-2·h^-1 which appeared at 14:00.The total monthly influx in June and July was 70 g·CO₂ ·m^-2,104 g·CO₂ ·m^-2,respectively.The net CO₂ flux in October(50 g·CO₂ ·m^-2·h^-1) was close to that in March(52 g·CO₂ ·h^-1)in the next year.During non-growing season,the diurnal CO₂ flux was close to zero during most time of the day,but showed a weak net CO₂ flux from 14:00 to 19:00(around 0.14 g·m^-2·h^-1).The net CO₂ flux of November(23 g·CO₂ ·m^-2·h^-1) was close to that in February(25 g·CO₂ ·m^-2·h^-1)in the next year.

• Preliminary Studies on Both the Mountain Blocking and Moisture Passage Effects
• GAO Deng-yi
• 2007 Vol. 26 (6): 1305-1310. 
• Abstract ( ) PDF (245KB) ( )
• There is a cross place between the Himalayas with a west-east direction and Hengduan Mountains with a north-south directions in which the Yarlung Zangbo River,Nu River and Lang Chang River are moving through it on the southeast part of the Tibet Plateau.As there is a special topography conditions,both of the mountain blocking and moisture passage effects on the distribution of precipitation,climatic and natural zones are obvious.The mountain blocking effects resist the warm and humid stream to make the great difference of the precipitation,climatic and natural zones between the two sides of the mountains.Meanwhile,both of the mountain blocking and moisture passage effects form the special distribution of precipitation,climatic and natural zones in this region,which make a great natural contribution for mankind of forming an ideal heaven.

• Feasible Study of on the Envisagement of Transporting the Moisture from South to North Sides of the Himalayas
• GAO Deng-yi;JIAN Yong-xiao
• 2007 Vol. 26 (6): 1311-1318. 
• Abstract ( ) PDF (315KB) ( )
• The Envisagement of transporting the moisture from south to north sides of the Himalayas is for improving the moisture transfer along the Great Yarlung Zangbo Canyon northwards.The strongest monsoon year is chosen by the climate data and the new South Asia Monsoon Index to be 1986.The above envisagement is diagnosed in this paper by a simple calculable way to discuss its feasibly in meteorology.The preliminary diagnostic analysis shows as the followings.Even if the topography blocking effects is an important factor for restricting the moisture transfer along the passage of the Great Yarlung Zangbo Canyon northwards,the convergence effect of large scale circulation related to the topography of Tibet Plateau is more important one.It is obvious that to change the large scale circulation is more difficult to alter the local topography.From the above,the envisagement of transporting the moisture from south side to north side of the Himalayas is very difficult to be practice,even though the topography of the Great Yarlung Zangbo Canyon and its north side has be changed.

• Size Distribution of Chemical Characteristics of Aerosol at Lijiang of Yunnan Province
• ZHANG Ren-jian;ZOU Han;SHEN Zhen-xing;WANG Wei
• 2007 Vol. 26 (6): 1319-1323. 
• Abstract ( ) PDF (347KB) ( )
• Chemical composition of atmospheric aerosols at Lijiang,Yunnan Province,China was monitored and analyzed.The results show that crustal elements such as Mg,Al,Ca,Si,K,Fe are the main composition of atmospheric aerosols at Lijiang and account for 82% of the total 20 elements' concentration.Concentrations of Pb,Se,Br in atmospheric aerosol at Lijiang are much higher than that over Mount Qomolangma Region.Enrichment factors of S,As,Se,Br,Pb in atmospheric aerosol at Lijiang which have close relation to human activity are very high.These results indicate that the impact of human activity at Lijiang are obvious and could not be neglected.