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General climatic controls and topoclimatic variations in

Central and High AsiaJrgen Bhner

Online Publication Date: 01 May 2006

To cite this Article: Bhner, Jrgen (2006) 'General climatic controls and topoclimatic

variations in Central and High Asia', Boreas, 35:2, 279 - 295

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General climatic controls and topoclimatic variations in Centraland High Asia

JURGEN BOHNER

BOREAS Bohner, J. 2006 (May): General climatic controls and topoclimatic variations in Central and High Asia. Boreas,

Vol. 35, pp. 279/295. Oslo. ISSN 0300-9483.

Basic features of current spatial and seasonal climate variations in Central and High Asia are presented. Large-scale circulation modes were inferred from NCAR/CDAS General Circulation Model (GCM) data andinterpreted with particular emphasis on the Asian Monsoon circulation. Using spatial high-resolution estimatesof radiation, temperature and precipitation covering Central and High Asia in a regular grid network with a grid-cell spacing of 1 km2, topoclimatic variations are investigated and discussed with respect to their major barometricand topographic controls. In general, weather patterns of Central and High Asia are determined by tropicalmonsoon as well as extratropical circulation modes. Associated synoptic conditions and processes, in particularthe alternation of tropical and polar air masses, lead to distinct large-scale variations valid for all climaticparameters in all seasons. The regional analysis and discussion of climatic gradients and environmental lapse ratesstress the significant role of Asias marked orography and its influence on advective processes, flow currents andtopoclimatic settings. Preliminary estimations of the annual water balance, however, are still afflicted with majoruncertainties owing to methodical limits in the spatial estimation of precipitation rates and widely lackingevapotranspiration records, particularly in the Tibetan Plateau and adjacent high mountain systems. Given the

importance of the mountainous water resources for the affected economies, further regional investigations on thewater cycle and its components are vital future tasks for climate research.

Jurgen Bohner (e-mail: [email protected]), Department of Geography, Georg-August-University Gottingen,D-37077 Gottingen, Germany; .

Climate impact studies, whether they deal with thereconstruction of palaeoenvironmental changes or theprediction of possible future impacts of changingclimates, have very diverse needs on climate inputdata. Most climate impact studies require local

information on present and future climates withtemporal high resolution and accuracy. Reliable spatialextended baseline climatologies are a crucial butessential data resource for palaeoclimatologists andclimatologists who are concerned with the studyof palaeoenvironmental changes. In complex high-mountain environments, moreover, spatially high-reso-lution information on the topoclimatic settings isfrequently required; these settings are seldom suffi-ciently represented by the available meteorologicalstation network. This is particularly valid for Centraland High Mountain Asia, where sparsely distributedmeteorological stations are mostly situated in loweraltitudes within valleys or oases belts, not representa-tive of the actual high mountain climates. Althoughthe extension of meteorological networks and theimplementation of automated screens lead to a betteroverall picture on climates and climatic processesfrom this climato-sensitive region, the interior areasof the Tibetan Plateau and its bordering high moun-tain ranges are less represented to date (Miehe et al.2001).

Owing to this general lack and hardly representa-tive distribution of climatic observations from Centraland High Mountain Asia, a statistical downscalingapproach for the spatial estimation of differentclimate variables was developed in the context of

research projects on late-Quaternary environmentalchanges in Central and High Asia. Using GeneralCirculation Model (GCM) outputs, Digital TerrainModel (DTM) data and available climate recordsfrom meteorological networks, extensive gridded cli-mate datasets were generated to: (1) detect presentclimatic controls of the natural and semi-naturalenvironments (e.g. glacial and periglacial environ-ments), (2) infer climate transfer functions from proxyrecords, necessary for palaeoclimatic reconstructionsand for the validation of palaeoclimate model simula-tions, and (3) predict and assess possible futureclimatic impacts on the natural and semi-naturalenvironments. These three application modes within

an overall framework for environmental changemodelling and model-based climate impact assess-ments were discussed by Bohner (2004a), Bohner &Lehmkuhl (2005) and Klinge et al. (2003). Given thegeneral lack of climate information in the high-mountain environments of Asia, in this article acompilation of selected climate layers are discussedin order to provide a first summarizing survey onthe current spatial and seasonal climatic variations

DOI 10.1080/03009480500456073 # 2006 Taylor & Francis


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of Central and High Asia. After a brief description ofmethods and material, the seasonal variations ofgeneral atmospheric circulation patterns and synopticprocesses are discussed. Then the zonal and hypso-metric differentiation of radiation, temperature andprecipitation is sketched with special attention givento large-scale atmospheric and local-scale topographiccontrols. Since the seasonal subdivision of the climaticregions of Central and High Asia is highly challen-ging, it is impossible to define seasons that would beequally valid for all regions and climatic parameters.In this article, I therefore discuss the spatial climatevariations on the example of selected months (Jan-uary, April, July, October), months that are taken tobe representative of the annual climatic variability.

Study area

The study area (Fig. 1) extends from 21836?N to53801?N at 908E and from 19854?N to 50827?N at its

eastern and western margin. The longitudinal exten-sion varies with latitude and is from 62811?E to117849?E at the northern margin and from 71806?E to108854?E at the southern margin. With a total of14 000 000 km2, the study area covers most of theCentral Asian mountain systems and adjacent basinsand thus spans a wide range of different climates. Thesecomprise the extreme dry autochthonous climates ofthe basins and deserts of Central Asia as well as thehyper-humid monsoon climates of the northern andnorth-easternmost parts of the Indian subcontinent.Figure 1 shows a schematic representation of Centraland High Asias physiography and identifies themost important topographic regions and locations

mentioned in the text.

Materials and methods

To date, a wide range of methods has been proposedfor the derivation of spatial climate data. Starting withgeostatistical (kriging) interpolation of point source(weather station) data, they also comprise multipleregression models as well as various physically basedmodelling approaches, and thus vary widely in com-plexity and sophistication. For a review of methodicalalternatives, refer to Chapman & Thornes (2003) andBohner (2004b, 2005). The seasonal and annual

distribution patterns of radiation, temperature, preci-pitation and evapotranspiration discussed in thisarticle were approximated using statistical downscalingof GCM outputs and terrain parameterization meth-ods. The climate model based approach was selected inorder to support environmental change modellingapplications with climate input data in a physicallyconsistent manner (Bohner & Lehmkuhl 2005). In thefollowing, the methods and considered databases are

only briefly sketched. A comprehensive description ofthe entire downscaling scheme and involved methods ispresented in more detail in Bohner (2004b, 2005).

The empirical database at the core of methoddevelopment comprised temperature and precipitationrecords from more than 400 meteorological stations,available as monthly time series or long-term meanswith a highest data density in the period 1961/1990.Evapotranspiration series were only available from 64sites of the Peoples Republic of China. These werecomputed according to the Penman equation(Schrodter 1985) and provided by A. Thomas (pers.comm. 2004). Time series were checked and homo-genized according to the measures described in Bohner(1996). A critical assessment of data sources and dataquality is given in Miehe et al. (2001). Figure 2 is anoverview of the spatial distribution of observation sitesand reveals the sparse cover and data availability in theinterior areas of the Tibetan Plateau.

The Digital Terrain Model (DTM) was obtainedfrom GTOPO-30 sources (edcaac.usgs.gov/gtopo30/

gtopo30.html). The GTOPO-30 global elevation modelhas a resolution of 30 arc seconds, corresponding to alongitudinal resolution of about 926 m. The latitudinalresolution varies with longitude between roughly 900 m(at 208N) and 550 m (at 538N). The GTOPO-30 wastransformed into a standard cartesian DTM with agrid cell spacing of 1 km2, defined for an Alberts EqualArea Projection via ordinary kriging (Matheron 1963,1973). GCM predictor variables were inferred fromNCAR/CDAS reanalysis series (Kalnay et al. 1996)performed by the US National Center for Environ-mental Prediction (NCEP) and the National Center forAtmospheric Research (NCAR). The retroactivelymodelled records contain free atmosphere variables

(e.g. geopotential height, temperature, moisture) for 13discrete atmosphere layers in a regular grid networkwith a horizontal resolution of 2.58by 2.58 (Lat/Lon.)as well as climate variables (e.g. cloud cover, precipita-tion) defined on a Gaussian grid with a resolution ofapproximately 1.98by 1.98(Lat./Lon.). The parametersfor characterization of the large-scale circulationmodes (e.g. u-wind and v-wind component, precitablewater, cf. Malberg 1994) were explored on themultiple grid point level using continuous verticaland horizontal approximation schemes in order toenable a methodically consistent assimilation ofalternative GCM outputs with differing discretisations(e.g. ECHAM-GCM palaeo-simulations; cf. Bohner &

Lehmkuhl 2005).Temperature and precipitation layers were estimated

by statistical downscaling (Bohner 2004a,b, 2005). Ingeneral, statistical (empirical) downscaling proceduresexplore the relationship between large-scale circulationmodes (represented by GCM predictor variables) andcorresponding local variations of single weather vari-ables (predictant variables, observed at one or a set ofmeteorological stations), using multivariate statistical

280 Jurgen Bohner BOREAS 35 (2006)


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analyses. Because a once obtained empirical down-scaling function enables a simulation of regionalweather variations on the base of the physicallyconsistent output of a GCM, statistical downscalingis most frequently used in case studies and climatechange impact assessments (Von Storch 1995; Gyalis-tras & Fischlin 1996; Gyalistras et al.1998). Assumingspatio-temporal variations of predictant variables to bepredominantly controlled by large-scale tropospheric

processes and regional to local-scale terrain determined(or at least terrain affected) processes and topographicsettings, in this study, terrain attributes such as relativealtitudes above drainage network, horizon screeningand complex process parameterizations (e.g. cold airflow, pressure drag parameterization, cf. Emeis 1994)were integrated in the downscaling scheme. Usingmultivariate statistical analyses to compute spatialprediction functions, the entire procedure yields rea-

sonable estimations of temperature distributions withcoefficients of determination of /93% for monthlyrecords. Instead, precipitation estimates were distinctlyless accurate, attaining an explanation in the order ofonly 70%. We assume this is mainly due to the insuf-ficient GCM resolution, which, particularly in con-vective dominated precipitation regimes, lies beyondthe characteristic precipitation representativeness ofabout 100/150 km (Bohner 1996). Modelled precipita-

tion and temperature estimates were subsequentlycorrected by a separately interpolated residue layer,computed via ordinary kriging (Matheron 1963, 1973).

Owing to lacking homogenous radiation recordsfrom the study area, solar radiation was consistentlyestimated using a semi-empirical modelling approach.Based on GCM pressure and specific humidity data,clear sky tropospheric attenuation was first approxi-mated by an atmosphere-mass parameterization

Fig. 1. Study area (Bohner & Lehmkuhl).

BOREAS35 (2006) Climatic variations in Asia 281


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according to Malberg (1994). Subsequently, the cloud-induced reduction was estimated using GCM cloudcover data. The common Angstrom approach (cf.Deacon 1969) proved suitable for estimating overcastsky effects. Model calibration considered map sourcescovering different parts of the study area (Lydolph1977; Rao 1981; Domros & Peng 1988). Monthlyradiation modelling was performed with an integration

frequency of 60 minutes under consideration of hor-izon screening and sun-ray refraction (Bohner &Portge 1997).

Since only very few meteorological stations havepublished records required for computing evapotran-spiration rates according to more complex methods,evapotranspiration rates were estimated according tothe Wang hyperbolic equation (Hoffmann 1993;Bohner 1996). The equation was recalibrated consider-

ing the evapotranspiration and climatic water balanceswere subsequently inferred from precipitationand evapotranspiration rates. Although the annualevapotranspiration rates were estimated with sufficientaccuracy, attaining an R2 of 87.1%, the mapped waterbalance yields no more than a preliminary estimationof this important climatic parameter due to the sparseempirical database.

Monthly resolution climate layers were performedon a regular grid network of 3500/4000 grid cells,each grid cell covering 1 km2. The 1-km horizontalresolution refers to the significant resolution of theGTOPO-30 digital terrain data sources, but was like-wise assumed to be a suitable compromise betweencomputational efficiency on the one hand and anadequate representation of mountainous climates onthe other. In accordance with the DTM, geo-referenced

Fig. 2. Spatial distribution of climate time series (squares), long-term climate mean values (dots), NCAR/CDAS circulation data (cross) andNCAR/CDAS climate data.



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climate data are defined for an Alberts Equal AreaProjection (standard parallels: 258N, 458N). Allestimated climate layers refer to the period 1961/1990.

Atmospheric circulation and synoptic processes

The representation of troposphere circulation andsynoptic processes is mainly based on NCEP/NCARfree atmosphere variables of the period 1961/1990(Kalnayet al. 1996) drawn from discrete tropospherelayers (1000, 925, 850, 700, 500, 200 hPa) and sea level.Referring to the whole of Asia, Figs 3 and 4 show airpressure distribution at sea level, the geopotentialheight of the 500 hPa layer and the relative topographyof the 500/200 hPa layer in January and July.

January

In winter, the mid-upper tropospheric planetary frontalzone (200/500 hPa) is characterized by strong pressure

gradients. Since the Tibetan Plateau acts as a coldsource and induces a quasi-permanent cut-off effect inthe upper troposphere, the flow pattern in the 200 hPalayer is split into two discrete branches. Figure 3expresses these only slightly due to the use of long-term means. The stronger southerly branch follows theHimalayan arc and reaches its southernmost positionabove the Ganges lowlands. Linked to strong tempera-ture and pressure gradients, the 200 hPa layer upper air

jets exhibit wind speeds in excess of 180 km/h (Lydolph1977). The weaker northern branch has its northern-most position above the Altai and Alatau and thenheads southeast, merging with the southerly branchover the east coast of China at about 30/358N. During

winter, the quasi-stationary waves of the upper tropo-sphere extratropical westerlies show a characteristicridge positioned to the west and southwest of theTibetan Plateau. This is followed by a downstreamtrough in the 700/200 hPa layer over the Japaneseocean. The anisobaric mass movement at the subtro-pical ridge causes an anticyclonic cell which is parti-cularly marked at the 500 hPa level above the ArabianSea, but not as distinct at sea level. In contrast, thetrough further east induces cyclonic activity and adynamic low whose continuation in the Aleutian Lowextends to the northern Pacific lower troposphere. Thesouthwest/northeast pressure gradient in the 700/200 hPa layer results in northwesterly winds over

East Asia that favour subsidence and autochthonousdry climate characteristics in wide parts of the northernand eastern study area.

The January mean sea level isobars reveal a broadhigh pressure system over Mongolia and North China,the so-called Asiatic High, with secondary divergenceaxes in East China and the Tarim Basin. The core ofthe Asiatic High is situated over the northwesternMongolian basins and is induced by the low levels of

incoming radiation in combination with enhancedradiative cooling. This is caused by the surroundingmountains, which prevent heat advection of western airmasses into the region. The extremely shallow AsiaticHigh is already dissolved at the 850 hPa layer andoverlaid by an elongated trough above its easternsector. The effect of allochthonous influences on thenear-ground air pressure distribution is expressed inthe cyclonic curvature of the isobars over the westernand northwestern Tian Shan forelands, and marks themean January trajectories of eastward-propagatingdisturbances. With a core pressure below 1000 hPa,the Aleutian Low represents the North Pacific counter-part of the Asiatic High. The steep pressure gradientbetween these two regions results in northwesterly tonortheasterly winds and influences large areas ofCentral and East Asia during winter and the transi-tional seasons. The East Asian Winter Monsoon oftenoccurs through surges of dry continental polar airwhich partly reach the Gulf of Bengal (Nieuwolt 1981).The mean boundary between continental cold dry air

and tropical warm air is marked by the steep pressuregradient of the Asiatic High divergence in South Chinathat occurs at about 20/258N. The North Indiansubcontinent is mostly unaffected by continental coldair surges due to mountains along its borders. At airpressures between 1015 and 1020 hPa, pressure gradi-ents and wind speeds are low above the Indiansubcontinent. North of 258N, the continental area isdominated by northwesterly winds. Northeasterly winddirections (Northeast Monsoon) only occur above theBramaputra plains. The South Asian Winter Monsoonresults from subsiding air motion in the northernsection of the subtropical anticyclone and causes stablestratification and enhanced aridity as part of the

Hadley circulation.

April

During spring, rising temperatures on the TibetanPlateau and the subsequent warming of the mid-troposphere cause pressure gradients to decrease. Theupper troposphere Westerlies over the Himalayan arcare weakened, while the northern branch of theWesterlies is strengthened. The trough over East Asiais also weakened but persists during spring. At sealevel, the divergence axis at the Tarim Basin dissolves,causing the Asiatic High to weaken and drift north-west. With the weakening of the Aleutian Low, the

spring months in Central and East Asia are character-ized by reduced pressure gradients. Although thenorthern and northeastern investigation areas aremore frequently affected by synoptic disturbances,the Tian Shan forelands, the Tarim Basin and EastChina are still influenced by continental air due to theprevailing northerly winds. In southeast China, southof about 25/308N, the growing influence of the PacificHigh, in April at about 158N, is revealed by easterly to



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Fig. 3. Mean circulation pattern in January. Black dotted line/sea level pressure (hPa). Grey line/heights at 500 hPa (gpdm). White line/thickness of 500/200 hPa layer (gpdm).

Fig. 4. Mean circulation pattern in July. Black dotted line/sea level pressure (hPa). Grey line/heights at 500 hPa (gpdm). White line/thickness of 500/200 hPa layer (gpdm).



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southeasterly wind directions. At the convergence zone,the Polar Front forms a marked boundary of airmasses at the 850 hPa layer, separating moist subtro-pical and dry continental air at the so-called Mei-YuFront (cf. Domros & Peng 1988). Above the Indiansubcontinent the rapid warming results in a thermaldepression over the Ganges lowlands with a corepressure below 1015 hPa. The resulting cyclostrophicwind pattern plays an important part in the initialphase of the Indian Summer Monsoon. Wind direc-tions turn from northwesterly over the Indus andGanges lowlands to southwesterly above the Gulf ofBengal. The heterogeneous situation of the sea levelflow pattern already points towards the large-scalechange to the Summer Monsoon circulation.

July

As shown in Fig. 4, a shallow trough forms overCentral Asia in the 200/500 hPa layer in July, culmi-nating over the Mongolian Altai at about 458N/958E.

Compared to the April position, the 500 hPa anti-cyclone of the Pacific High has shifted north by about158, reaching its most northerly position of 308Nduring the last pentad of July (Domros & Peng1988). The northern mountain regions of the studyarea are affected by a zonal flow pattern, whichseparates the subtropical warm and polar cold air inthe middle troposphere at the Tian Shan Front. Owingto the enhanced warming of the Tibetan Plateau duringMay and June, a shallow heat low is established in theplanetary boundary layer (400/500 hPa). At the sametime, a warm anticyclone is established at 500 hPa overthe southern sector of the Tibetan Plateau, the so-called Monsoon High. Since the Monsoon High is

centred above the upper Tsangpo Depression in SouthTibet, the upper troposphere Westerlies are replaced byan easterly jet. Two factors are commonly heldresponsible for the warming of the middle and uppertroposphere: the summer plateau circulation, alsotermed Summer Plateau Monsoon, transporting heatinto the upper troposphere, and the vertical transfer oflatent heat in huge convection cells above northeastIndia. The latter is particularly relevant on the wind-ward slopes of the Himalaya (Flohn 1968, 1987;Domros & Peng 1988).

Replacement of the northern, descending branch ofthe subtropical anticyclone by ascending motion causesthe lower troposphere to destabilize, which permits the

development of the Summer Monsoon Low overNorthern India and Pakistan. The northwesterly shiftof the Inner Tropical Convergence Zone (ITCZ) and itsdissolution into huge convection clusters places theIndian subcontinent under the influence of westerly tosouthwesterly monsoonal air masses. Above the Gulfof Bengal, the monsoon current splits into twobranches. The eastern branch determines the weatherpatterns of southwest China and favours an extensive

transfer of latent heat along the Three River Gorges farinto the southeastern Tibetan Plateau. The westernbranch is deflected by the Himalaya Arc into easternand northeastern currents. In Fig. 3, the resultingconvergence of the monsoon low is shown with a corepressure of less than 997 hPa.

With the dissolution of the Central Asian andNorthern Pacific pressure centres during spring andsummer, the Pacific High gains significance, affectingthe surface air flow of East Asia. Its northward shift islinked to a corresponding shift of the Mei-Yu Front, sothat eastern China is increasingly influenced by sum-mer monsoonal southeasterly winds in May and June.The precipitation sector of the Mei-Yu Front reachesthe Yangtse in June, and, in a weakenend form, thelowlands on the Huang-He in July. Because ofenhanced heating in the arid areas of Central Asia,thermal lows develop over the Tarim Basin and InnerMongolia, stabilizing the southeasterly winds in theeastern part of the study area. To the west andnorthwest of these convergences, northerly to north-

westerly wind directions remain dominant.

October

During mid-August and September, winter circulationpatterns first manifest themselves in the frequentoccurrence of synoptic disturbances and troughs inthe upper troposphere over the Himalaya. Thesetemporarily dissolve the warm anticyclone in southeastTibet and thus induce characteristic break situationsin the monsoonal weather pattern. These situationsonly last a few days and are typically dissolved with therenewed formation of the Monsoon High during thefinal attack (Ramaswamy 1962; Miehe 1990). Stable

upper troposphere Westerlies are first established overthe Himalayan arc, when the decreasing radiation atthe Tibetan Plateau during October favours risingmeridional temperature and pressure gradients in themiddle and upper troposphere. In northern India andPakistan, winter monsoonal air flow and weatherpatterns are not established until mid-October, whereasin East Asia the change to winter circulation patternsat the surface layer is already completed by lateSeptember. The Asiatic High is completely re-estab-lished above the northern Dsungarian Basin. With acore pressure of more than 1024 hPa, the OctoberAsiatic High is more strongly developed than its Aprilequivalent.

Radiation

The following section considers the short-wave (solar)radiation income, as derived from the modelling resultsoutlined above. All values refer to inclined surfaces andare therefore only comparable to global radiationamounts in plain areas. Examples of the spatial



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Fig. 5. Mean solar radiation on inclined surfaces for January (A), July (B) and year (C).



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distribution of the overall solar radiation income(annual and monthly means) are given in Fig. 5A(January), 5B (July) and 5C (year).

Annual radiation distribution

In the study area, major features of the solar radiationincome are determined by its huge geographic extent.Reaching from about 22 to 538N, the astronomical daylength on 21 December varies between 10.2 h and7.7 h. The solar altitude at noon ranges between 46.58and 13.58, which causes major lighting contrasts andmarked topographic variation in winter. During sum-mer, the northern sun altitude of 60.58at 538N is about308lower than at 208N, but this is compensated by daylengths of up to 16 h.

Figure 5C reveals the significance of atmosphericextinction processes in showing a marked increase ofradiation with elevation. Representing the latitudinalradiation gradient, the lowlands receive daily meanannual totals of about 1200/1300 J / cm2 d1 at their

northern limits and roughly 1800/

1900 J/

cm

2

d

1

attheir southern limits. Mountain areas above 5000 mreceive more than 2000 J / cm2 d1, reaching morethan 2500 J / cm2 d1 on the southern slopes of high-mountain crests. Topographic differentiation becomesprogressively more pronounced with rising latitude.Deep valleys and northern slopes of the Altai receiveless than 1200 J / cm2 d1, southern slopes more than1500 J / cm2 d1.

Seasonal variations

Figure 4A shows a marked latitudinal gradient for thespatial radiation distribution in January. With a day

length of approximately 10.5 h, the southernmostplains of the study area receive 1300/1400 J /cm2 d1, compared to only 300 J / cm2 d1 re-ceived in northernmost areas such as the Mongolianbasins. With rising altitude and decreasing extinction,the plain surfaces of the Tibetan Plateau receive 1000 /1500 J / cm2 d1. A steep meridional gradient alsoprevails in comparable settings. Owing to low solaraltitudes, inclined south-facing surfaces receive morethan twice as much as north-facing slopes, especially inthe northern high mountain areas. For the steepnorthern slopes of the western Altai, minimumamounts of less than 100 J / cm2 d1 are obtained,while adret slopes at the same elevation receive up to

600 J

/ cm2

d1

. Topographical variation is also validfor the Himalaya, where crests with southern aspectsmay reach up to 2100 J / cm2 d1. Owing to thescreening of horizons, the radiation partly decreasesto 1000 J / cm2 d1 in narrow valleys.

With increasing day length and sun altitudes,spring is characterized by a marked increase in radia-tion and less predominance of meridional contrasts.For the northern limits, estimates for April range

between 1700 and 1900 J/ cm2 d1. Because of thehigher fraction of cloud cover in South China, radia-tion values tend not to exceed 2100 J / cm2 d1, whilethe comparably dry conditions in North India lead tovalues of more than 2500 J / cm2 d1. For highmountain areas above 5000 m, daily insolationtotals of 2600 to 2800 J / cm2 d1 at the TibetanPlateau and more than 3000 J / cm2 d1 in the Altaimountain plateaus confirm the absence of a large-scalemeridional gradient. However, orographic differentia-tion is still marked in steep terrains, with totals of morethan 3200 J / cm2 d1 on Himalayan south-facingslopes.

Figure 5B reveals an almost total dispersal of large-scale meridional radiation gradients in July. Comparedto April, the rise in total amounts is only small.Although noon altitudes of the sun differ by 308, thelower inclination angle of about 608 in the northern-most latitudes is compensated by a day length exceed-ing 16 h. Total insolation of more than 2300 J /cm2 d1 in the south Siberian steppes is only

matched by the dry plains of the Thar Desert in thesouthern study areas. Owing to the higher fraction ofthe convection clusters in northeast India and EastChina (e.g. in the Red Basin), daily totals decrease toabout 1900/2000 J / cm2 d1, even dropping belowthe April values. In July, the spatial distribution ofsolar radiation is determined by elevation effects andthe resulting atmospheric transmission. This is evidentin the high mountain crests of the Himalaya, theTibetan Plateau, the Karakoram or the Tian Shan, allobtaining more than 3300 J / cm2 d1 and reachingmaximum values of up to 3600 J / cm2 d1. Anorographical differentiation is only apparent in theAltai and adjacent mountainous areas when totals of

less than 1900 J/ cm

2

d

1

are received on steepnorthern slopes or valley bottoms.The fall is generally characterized by a marked

decrease in solar radiation, so that October mirrorsnearly January conditions. A steep meridional gradientis revealed by radiation rates below 600 J / cm2 d1 atthe northernmost latitudes and about 1600 J /cm2 d1 in the southern plains of the study area.Estimates for plain settings of the Tibetan Plateaucommonly range between 1600 and 1900 J / cm2 d1.Overall, October values range between 2500 J /cm2 d1 at southern crest slopes of the Himalayaand less than 500 J / cm2 d1 on north-facing slopesof the Altai.

Thermal conditions

The following establishes the basic characteristics ofspatial and seasonal temperature variations, takinginto account the annual state of atmospheric circula-tion and associated advection as well as radiation asthe major thermal controls. Examples of long-term



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Fig. 6. Mean temperature distribution in January (A), July (B) and year (C).



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estimates of annual and monthly means are given inFig. 6 for January (A), July (B) and the year (C).

Annual temperature distribution

As shown in Fig. 6C, the investigation area ischaracterized by extreme thermal differences. In gen-eral, the spatial distribution of temperature is predo-minantly determined by hypsometric differentiation.With an average lapse rate of roughly /0.006 K / m1,large areas of the central Highlands and the northernand northwestern mountain areas are situated in anegative temperature scope. In the mountain-rimmedbasins of the Altai, the 08C limit reaches down to about1500 m, compared to 4800 m in the upper Tsangpodepression. At the Tibetan Plateau, annual means of/108C are common for the crests north of the centralPlateau axis. In the lowlands of the study area, ageneral temperature decrease from west to east can beobserved in the southern and northern margin. In theNorth Indian and Pakistan plains, the high annual

temperature level of about 25/

288

C results fromenhanced heat surplus, which is particularly pro-nounced in winter and the transitional seasons. Thecomparably low values of less than 238C in southernChina mostly reflect negative winter anomalies. In thenorthernmost lowlands, annual means range between0/28C in northeastern China and 4/68C in the south-ern Siberian steppes. With annual means between 7 and138C in the lowlands and huge basins north and east ofthe Tibetan Plateau, large areas of arid Central Asiacan be assigned to the temperate climates. However, theterm temperate (derived from European experience) ismisleading as far as the marked seasonal variations areconcerned.

Seasonal variations

Although the temperature distribution in Januaryappears complex, major controls can be identified. Inline with the marked radiation gradient, Fig. 6A alsoreveals distinct meridional differences. Negative tem-perature anomalies throughout the eastern study high-light the significance of air mass origin for thermalconditions. The frequent cold air surges cause tem-peratures to drop about 58C below the latitudinalmean. The 08C isotherm is situated at about800 m a.s.l. in the southern Qinling forelands, between2800 and 3400 m a.s.l. along the Three River Gorges

and in the central Himalaya, and between 1600 and2000 m a.s.l. in the western Himalaya and Karakoram.With the exception of the western Tian Shan forelands,which benefit from advection of latent heat by westernair masses, temperatures north of 378N remain below08C. While frequent dry adiabats and subsiding airmotion in the subtropical anticyclone over North Indiaresult in vertical lapse rates of up to /0.0088C / m1, amarked decrease in the vertical differentiation, reach-

ing positive gradients at peplosphere level in thenorthern sections of the study area, is apparent (Fig.6A). In the Mongolian basins, enhanced cooling andstagnation of air lead to the formation of cold airdomes, revealed by values of less than /258C.Comparable values are only reached in the highmountain areas at elevations above 5000 m a.s.l.

Thermal conditions in spring are characterized bythe dissolution of meridional temperature contrasts inthe northeastern and eastern study area. In the south-ern Siberian plains, persisting snow cover and thenorthwesterly shift of the Asiatic High are linked toincreasing meridional temperature contrasts in thenorthwestern areas between 408 und 508N. In April,the northern and western Tian Shan forelands aretherefore more often affected by continental coldair than North and East China. With increasingatmospheric instability, particularly in arid CentralAsia, vertical gradients reach values of about /0.005to /0.0068C / m1. This leads to a more distinctvertical temperature differentiation in the northern

mountain areas. Apart from the huge basins, wheretemperatures can rise to 158C, the general springwarming is most pronounced in the upper TsangpoDepression, with positive estimates for altitudes up to4900 m a.s.l. Elsewhere in the mountain ranges border-ing the Tibetan Plateau, the 08C isotherm remainsbelow 4500 m a.s.l.

Apart from altitude as the main control for tem-perature distribution, there is a complete dissolution ofthe meridional temperature differentiation in July.Enhanced heat surplus in the northern basins duringsummer causes temperatures to rise above 208C. Amarked maximum of 338C in the Turpan Depression isonly matched by the Thar Desert. Consistent with

frequent moist adiabatic air motions in the hugeconvection cells, the hypsometric gradient in southernmonsoon-controlled regions slightly decreases to about/0.005 K / m1. North of the Plateau axis, verticalgradients partly exceed /0.0078C / m1. Owing to thelarge radiation amounts and enhanced heat surplus,the Tibetan Plateau acts as a large-scale elevated heatsurface during summer. In line with positive tempera-ture anomalies in the middle to upper troposphere,negative monthly means in July only occur along themain adjacent ranges.

During fall, barometric conditions adapt to wintercirculation patterns. The increasing frequency of coldair surges is apparent in a dramatic temperature drop

in the lowlands and basins. Above 3000 m a.s.l., how-ever, an opposite tendency can be noted. In southernTibet, positive temperatures in the basins between theTranshimalaya and the Tangula Shan indicate apersistent heat surplus, a fact that is also expressed ina strictly hypsometric increase of the meridionalgradients in October. The rise of the 08C isothermfrom 1600 m in the Altai to about 5000 m a.s.l. in theTranshimalaya and upper Tsangpo is correspondingly



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pronounced. This finding, which appears to contradictthe relatively low amount of radiation obtained at theTibetan Plateau in October, shows that radiation isrelatively efficiently transformed into sensible heat atthe surface layer, which is less weakened by ablationthan in spring. Thus, comparably low vertical lapserates result from the persisting temperature levelin southern Tibet, with values of approximately/0.0058C

/ m1 in the Himalaya and along the Three

River Gorges.

Moisture conditions

Since variation in spatial precipitation is largely con-trolled by topographic setting, hilly terrains are char-acterized by a huge range of precipitation. Thefollowing outlines the overall patterns and features ofthe spatio-temporal moisture variations, particularlywhere they contribute to tropospheric processes. Pre-cipitation distribution patterns are given in Fig. 7 for

January (A), July (B) and year (C).

Annual precipitation distribution

In general, the distribution of spatial precipitation isextremely variable, ranging from less than 25 mm in theTarim Basin to more than 10 000 mm in the KashiHills. Taking into account alternating air masses andassociated processes of precipitation genesis, the over-all distribution of precipitation reveals some generalcontrols. These can roughly be classified into monsoo-nal variation patterns, on the one hand, and large-scalevariation patterns, on the other, caused by extratropicalWesterlies and their associated fronts and disturbances.

The latter pattern is observed in the western andnorthern high mountain systems and their respectivewestern and northwestern forelands. Precipitationregimes in these regions are dominated by westerndisturbances throughout the year. In the Hindukush,Karakoram, Pamir and West Kunlun, disturbancesoccur most frequently in winter, whereas in Tian Shanand Bogda Shan they are most common in spring. Inthe Alatau and Altai, disturbances are expressed asquasi-stationary fronts in summer. Precipitation ratesrapidly increase from 100/300 mm in the northwesternand western forelands, basins and valleys bottoms toroughly 600/1000 mm on windward slopes. Totals ofmore than 1500 mm are obtained in the Alatau, on

northern aspects of the Tian Shan and in the Hindu-kush. Cyclonic activity causes estimates of up to600 mm in the relatively dry West Kunlun, despitebeing sheltered by the Pamir and Karakoram. In mosteastern and southern humid to semi-humid areas of theinvestigation area, distribution of precipitation ismonsoonal. In the sphere of the East Asian Monsoon,precipitation increases towards the east and southeast,roughly ranging from 700 to 1500 mm. At windward

slopes of the southern Chinese Highlands and in themountain ranges bordering the Red Basin, 2000 mmare frequently exceeded. North of the Qinling Shan,precipitation totals significantly decrease to 400 mm inthe Ordos Plateau and to less than 100 mm in InnerMongolia. Marked contrasts also occur in the sphereof the South Asian Monsoon. Precipitation ratesprogressively increase towards the west and northfrom about 100 mm in the Thar Desert to roughly1000 mm in the foothills of the western Himalaya andthe western Ganges plains. Up to 2000 mm areobserved in the Assam plains, with marked maximumrates of more than 4000 mm for the windward southernslopes of the bordering mountain ranges at altitudesbelow 4000 m. However, in deep valleys and mountainrimmed basins, a dramatic reduction is observedthroughout the Himalaya. The significance of topo-graphic setting is best illustrated by the famous KashiHills, where the uplift of moist monsoonal air currentsleads to more than 10 000 mm deposited on southernslopes and less than 2000 mm on leeward slopes. The

variation pattern encountered at the Tibetan Plateaushows parallels to the situation described above, inparticular the general increase of totals from northwestto southeast. Nevertheless, it can only partly be labelledmonsoonal. The comparatively high estimates of up tomore than 1000 mm in the southeast Plateau and alongthe crest lines of the Three River Gorges are caused byallochthonous monsoon currents, while the amounts ofabout 400/1000 mm in the central and southernPlateau area predominantly result from convection(Flohn 1968). At the same time, increased advectionrates have to be assumed for the comparably dryNortheast Plateau, where the northern slopes of themountain ranges bordering the Qaidam Depression

receive more than 400 mm. However, a dramaticdecrease to less than 50 mm in the intramontane basinsand valley bottoms reveals the low frequency of frontsin this area. Dry conditions are also apparent in thewesternmost plateau area, which is sheltered fromwestern disturbances by the high mountain systemsof the Hindukush, Karakoram, Pamir and Tian Shan.However, estimates of 50/400 mm mostly result fromthe cyclonal activity during winter. The central high-lands of Tibet therefore mediate between the dominantprecipitation regimes of Asia.

Seasonal variations

In January, the precipitation distribution (Fig. 7A)mirrors the major trajectories of cyclonic activity. Inthe Tian Shan, the windward slopes and westernforelands receive precipitation totals of more than50/80 mm, increasing westwards from Bogda Shantowards the Talas Alatau and exceeding 200 mm in thewestern slopes of the Alai chain. In the Himalaya,which is much affected by upper troposphere distur-bances, the precipitation depression in the Sikkim



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Fig. 7. Mean precipitation distribution in January (A), July (B) and year (C).



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Himalayas marks the average reach of cyclonic activity.The western Himalaya and Karakoram receive pre-cipitation rates of approximately 30 to over 120 mm.For the inner Himalaya and the main ridge of theHindukush, totals over 200 mm are estimated forwesterly to southwesterly slopes. Owing to a stablewinter monsoonal flow pattern, convective precipita-tion rates in North India are limited. In northeastIndia, 50 mm are only exceeded at southern slopes andin the forelands of the Assam Himalaya. Although thecloudy cold air sector of the Polar Front covers all ofSouth China from the coast to the Yangtse duringwinter, precipitation totals of 50 mm are only exceededin the southeastern investigation area, which is influ-enced by Pacific air masses.

Western disturbances and their trajectories alsoinfluence large-scale patterns of precipitation distribu-tion in spring. This is indicated by a general east-to-west increase at higher altitudes in the western highmountain areas and their forelands, extending from thewestern Himalaya to the Karakoram, Hindukush,

Pamir and Tian Shan. As a result of increasingly zonalcirculation patterns in April, northwestern slopes of theTian Shan benefit from precipitation rates of morethan 200 mm. Comparable amounts can be calculatedfor the Kashmiri Himalaya and the Karakoram, withmaximum values obtained at northern and north-western aspects of the Hindukush. In valleys andbasins, values decrease to less than 20 mm of precipita-tion. With increasing atmospheric destabilization in thepre-monsoonal period, the monsoonal west-to-eastincrease in precipitation highlights the growing impor-tance of convection. While 50 mm is characteristic inthe Indus and Ganges lowlands, more than 200 mm isreceived by the Bramaputra plains and bordering

ranges. Favoured by the emergence of southwesterlywinds over the Gulf of Bengal, the windward slopes ofthe Khashi Hills and the foothills of the AssamHimalaya may receive in excess of 300 mm. In theThree River Gorges and southeast Tibet, precipitationvaries widely depending on the topographic setting,with characteristic low values of 20/100 mm. Southernand eastern China are influenced by convective pre-cipitation and the so-called plum rains associated withthe Mei-Yu Front. Precipitation here increases fromnorthwest to southeast and reaches 150/200 mm.

With decreasing cyclone frequencies in the westernmountainous areas, precipitation in valleys and basinsamounts to less than 10 mm during the summer

months (Fig. 7B). The eastern Tian Shan, the BogdaShan and the Altai benefit from the mean July positionof the Tian Shan Front as well as thermal convectionlinked to intense diurnal mountain wind systems. Onnorthern slopes, precipitation rates exceed 80 mm.Precipitation rates continue to increase from the east-ern Tarim Basin across the Gobi to the Ordos Plateau,exceeding 200 mm in the Red Basin and adjacentmountain areas. While the warm air sector of the

Mei-Yu Front south of the Yangtse is linked to loweramounts, converging South and East Asian monsooncomponents cause precipitation rates of over 200 mmin South China. Total amounts of more than 300 mmon windward slopes and crests indicate an extensivetransfer of latent heat along the Three River Gorgesinto southeastern Tibet caused by monsoon currents.Even in deep valleys, however, more than 100 mm isobtained. During the summer monsoon, variations inprecipitation across the Indian subcontinent are parti-cularly pronounced in the plains, where precipitationincreases by a factor of 10 from the Thar Desert to theBramaputra plains. This is mainly due to thermalconvection and tropical depressions originating in theGulf of Bengal (Rao 1981). These depressions followthe general monsoon current and take a northwesterlypath along the Himalaya, where they lead to precipita-tion totals of more than 1000 mm on the windwardslopes of the Kashi Hills and in the eastern Himalaya.On the Tibetan Plateau, totals range between less than50 mm in the western and northernmost areas and

more than 300 mm in the southeastern areas. Withcumuliform clouds covering more than 80% of centralTibet, precipitation mainly results from convection. Asdescribed above, northern and northeastern Tibetbenefits from the trough position above the MongolianAltai. Here, cyclonal activity is confirmed by theproportion of stratiform clouds, which increases fromless than 20% in the Tangula Shan to over 40% in theKunlun and Qilian Shan. Comparable estimates(e.g. exceeding 100 mm on the northern slopes of theQilian Shan in the northwestern Plateau area) mainlyresult from advective processes (Flohn 1968, 1987;Dronia 1987).

In October, the precipitation distribution of western

High Asia begins to point towards the large-scalecyclonal source. While precipitation totals in thenorthern Tian Shan forelands generally exceed theJanuary values, precipitation elsewhere remains belowthe January levels. Amounts of roughly 20 mm in theintramontane basins and valleys and over 200 mm infavoured topographical settings are characteristic ofthe whole of western High Asia. The contrast betweenpre- and post-monsoon period is revealed by precipita-tion rates of about 100/300 mm in the Ganges low-lands, which far exceeds the April totals. Here,precipitation mainly results from tropical depressions,which often reach storm strength during Octoberand November (tropical cyclones), and are linked to

high precipitation (Rao 1981). The monsoonal, strictlywest to east increase of precipitation thus remainscharacteristic of the post-monsoon period as well. Acomparable high level of precipitation is also apparentin the Three River Gorges and southeastern Tibet.Here, precipitation rates of about 50/300 mm clearlyexceed the pre-monsoon level obtained in April. Ineastern China, the large-scale Pacific orientation alsoprevails during October. With the exception of the



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topographically favoured mountain margins of theRed Basin, where amounts of 200 mm are fre-quently exceeded, precipitation increases eastwardsand southeastwards, ranging from about 20 to 50 mmthe Ordos Plateau to more than 200 mm in the southChinese Highlands.

Climatic water balance

Climatic variation is best summarized by looking at thespatial distribution of the mean annual water balance,a factor which comprises most climatic essentials.Consistent with the huge spatial variability of majorclimatic parameters, Fig. 8 reveals marked spatialvariation and a wide range of conditions rangingfrom the extremely moist to the extremely dry. In theThar desert, precipitation deficits reach /2000 mm,which results from low precipitation totals and

enhanced heat surplus throughout the year. Otherlarge parts of the study area are also characterizedby marked deficits. Annual totals of/1000 to nearly/2000 mm are obtained for the mountain-shelteredbasins of Central Asia (Tarim, Quaidam, Dsungarian,Uufs-Noor Basin) and indicate an autochthonousclimate with precipitation totals of less than 100 mmand extreme seasonal temperature variations. Theannual range of monthly means (more than 358Cwith a maximum of about 458C in the Uufs-NoorBasin) results from the summer heat surplus followedby enhanced radiational cooling in winter. In easternand southern areas in contrast, the water balanceprogressively increases, almost reaching positive valuesin the area of the East Asian and South Asian SummerMonsoon. Enormous precipitation amounts in theAssam plains and adjacent windward slopes of theHimalaya and Kashi Hills cause the water balance to

Fig. 8. Mean annual water balance.



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reach maximum values of more than 5000 mm. Never-theless, the winter season remains arid. With an annualtemperature range of roughly 10 to 208C, seasonaltemperature variations are less pronounced. Somepositive water balances can be found in the northernmountainous regions of the study area. Up to 300 mmis achieved in the Altai, which benefits from low

radiation income and low temperatures. Comparablevalues in the western high mountain areas indicatehigher precipitation levels due to the frequent occur-rence of western disturbances. The latter aspect, inparticular the advection of latent heat in winter, is alsoresponsible for the comparably moderate annual tem-perature variation, which characteristically rangesbetween 20 and 258C. The water balance in the Tibetanplateau varies widely between about /900 mm in thewesternmost valleys and basins and 800 mm at thesoutheastern high mountain crests. However, thesevalues are calculated on the basis of annual evapo-transpiration estimates of about 400 to 1000 mm. Inview of the high transpiration velocity in these levels of

the troposphere, they are likely to underestimate thereal values.

Conclusions

The study is a survey of the current spatial andseasonal climate variations in Central and High Asiausing extensive gridded climate estimates at 1 km2

resolution consistently approximated by means ofstatistical downscaling of GCM data and DTM basedterrain parameterization methods. Despite a sparse andhardly representative distribution of available observa-tions from meteorological stations, seasonal differen-

tiated analyses reveal the main characteristics of thespatial climate variations, its driving atmosphericforces, and topographic controls on a regional scale.However, methodical limits in the estimation ofprecipitation rates and widely missing evapotranspira-tion records, completely lacking over large domainsof the interior Tibetan Plateau and adjacent Highmountain ranges, only enable an uncertain calculationof the annual climatic water balance. Thus, there isan obvious necessity of additional data assemblyfrom regular network sources and the inclusion ofmeasurement campaigns. Moreover, a combinationof diagnostic data analyses, regional climate model-

ling approaches, and remote-sensing techniques isencouraged to provide more reliable estimates ofthe climatic water balance and its components atcommensurate scales. Given the number of countriesaffected by the mountainous water resources of HighAsia, the assessment and modelling of the waterresources is generally recommended as an urgent taskfor future climate related research in this climato-sensitive region.

Acknowledgements. / I thank the German Ministry for Educationand Research (BMBF) and the German Research Society (DFG)for financial support. This work was part of a BMBF Projecton Terrestrial Palaeoclimates from 1998 to 2001 (J. Bohner &F. Lehmkuhl FKZ: 01LA9838). I am grateful to two anonymousreviewers, Lewis Owen, Jim Teller and Jan A. Piotrowski for helpfulsuggestions and valuable comments on the scientific content. Inaddition, I thank Kira Gee for smoothing the English. This is acontribution to IGCP 415 (Glaciation and Reorganization of AsiasNetwork of Drainage), co-edited by Professor Jim Teller.

References

Bohner, J. 1996: Sakulare Klimaschwankungen und rezente Klima-trend Zentral- und Hochasiens. Gottinger Geographische Abhan-dlungen 101, 181 pp.

Bohner, J. 2004a: Der klimatisch determinierte raum/zeitlicheWandel naturraumlicher Ressourcen Zentral- und Hochasiens:Regionalisierung, Rekonstruktion und Prognose.In Gamerith, W.,Messerli, P., Meusburger, P. & Wanner, H. (eds.): Alpenwelt-Gebirgswelten. Inseln, Brucken, Grenzen. Tagungsbericht und wis-senschaftliche Abhandlungen 54. Deutscher Geographentag Bern2003, 151/160.

Bohner, J. 2004b: Regionalisierung bodenrelevanter Klimaparameter

fur das Niedersachsische Landesamt fur Bodenforschung (NLfB)und die Bundesanstalt fur Geowissenschaften und Rohstoffe(BGR). Arbeitshefte Boden 2004/4, 17/66.

Bohner, J. 2005: Advancements and new approaches in ClimateSpatial Prediction and Environmental Modelling. Arbeitsberichtedes Geographischen Instituts der HU zu Berlin 109, 49/90.

Bohner, J. & Lehmkuhl, F. 2005: Climate and environmental changemodelling in Central and High Asia. Boreas 34, 220/231.

Bohner, J. & Portge, K. H. 1997: Strahlungs- und expositionsges-teuerte tagesperiodische Schwankungen des Abflusses in kleinenEinzugsgebieten.Petermanns Geographische Mitteilungen 141, 35/42.

Chapman, L. & Thornes, J. E. 2003: The use of geographicalinformation systems in climatology and meteorology. Progress inPhysical Geography 27, 313/330.

Deacon, E. L. 1969: Physical processes near the surface of the earth.

In Flohn, H. (ed.): World Survey of Climatology, 2, 39/104.Elsevier, Amsterdam.

Domros, M. & Peng, G. 1988: The Climate of China. 360 pp.Springer, Berlin.

Dronia, H. 1987: Weather during the expedition. In Hovermann, J. &Wang, Wenying (eds.): Reports on the Northeastern Part ofthe Qinghai-Xizang (Tibet) Plateau, 4 17/437. Science Press,Beijing.

Emeis, S. 1994: Bestimmung und Parametrisierung des Druckwieder-stands an Hindernissen in der atmospharischen Grenzschicht.Berichte des Deutschen Wetterdienstes 191, 173 pp.

Flohn, H. 1968: Contributions to a meteorology of the TibetanHighlands. Atmospheric Science Paper 130, 120 pp.

Flohn, H. 1987: Recent investigations on the climatogenetic role ofthe Quinghai-Xizang Plateau: now and during late Cenozoic. InHovermann, J. & Wang, Wenying (eds.): Reports on the North-eastern Part of the Qinghai-Xizang (Tibet) Plateau, 387/416.Science Press, Beijing.

Gyalistras, D. & Fischlin, A. 1996: Derivation of climatic changescenarios for mountainous ecosystems: a GCM based method andthe case study of Valais, Switzerland. Swiss Federal Institute ofTechnology ETHZ, Zurich, Switzerland, Systems Ecology Report22, 21 pp.

Gyalistras, D., Wahrenberger, C., Rohrer, M., Lorenzi, D. & Riedo,M. 1998: Temporal downscaling /a method to reduce the climaticinput requirements of impact models. In Proceedings of the7th International Meeting on Statistical Climatology, 37/38.



18/18

Canadian Climate Centre for Climate Modelling and Analysis,

Victoria, Canada.

Hoffmann, J. 1993: Geomorphologische Untersuchungen zur jung-

quartaren Klimaentwicklung des Helan Shan und seines westlichen

Vorlandes.Berliner Geographische Abhandlungen 57, 187 pp.

Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D.,

Gandin, L., Iredell, M., Saha, S., White, G., Woollen, J., Zhu, Y.,

Leetmaa, A., Reynolds, R., Chelliah, M., Ebisuzaki, W., Higgins,

W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang, J., Jenne, R. &

Joseph, D. 1996: The NCEP/NCAR 40-Year Reanalysis Project.Bulletin of the American Meteorological Society 77/03, 437/471.

Klinge, M., Bohner, J. & Lehmkuhl, F. 2003: Climate patterns, snow

and timberline in the Altai Mountains, Central Asia. Erdkunde 57,

296/308.

Lydolph, P. 1977: Climates of the Soviet Union. World Survey of

Climatology 7, 443 pp.

Malberg, H. 1994: Meteorologie und Klimatologie. 332 pp. Springer,

Berlin.

Matheron, G. 1963: Principles of Geostatistics.Economy Geology 58,

1246/1266.

Matheron, G. 1973: The intrinsic random functions and theirapplications. Advances in Applied Probability 5, 438/468.

Miehe, G. 1990: Langtang Himal / Flora und Vegetation alsKlimazeiger und -zeugen im Himalaya. Dissertationes Botanicae158, 530 pp.

Miehe, G., Winiger, M., Bohner, J. & Yili, Z. 2001: The climaticdiagram map of High Asia. Erdkunde 55, 94/97.

Nieuwolt, S. 1981: The climates of continental southeast Asia. InTakahashi, K. & Arakawa, H. (eds.): World Survey of Climatology

9, 1/66. Elsevier, Amsterdam.Ramaswamy, C. 1962: Breaks in the Indian Summer Monsoon as a

phenomenon of interaction between the easterly and the subtro-pical westerly jet stream. Tellus 14, 337/349.

Rao, K. N. 1981: Tropical cyclones of the Indian seas. In Takahashi,K. & Arakawa, H. (eds.): World Survey of Climatology 9, 257/281.Elsevier, Amsterdam.

Schrodter, H. 1985: Verdunstung: Anwendungsorientierte Messverfah-erfahren und Bestimmungsmethoden. 186 pp. Springer, Berlin.

Von Storch, H. 1995: Inconsistencies at the interface of climateimpact studies and global climate research. MeteorologischeZeitschrift Suppl. 4, 72/80.


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