Role of High Mountains in Climate and Water Cycle over Dry Regions of Central Asia

Vladimir AizenUniversity of Idaho, U.S.A.

Amur

Yenisey

Ob’

20

40

6080 100 120

140

160

6060

40 40

20 20

SirdaryaAm

ydarya Tarim

Ili

> 1,000,000km2 mountainous area over 1,000 m 45,000 km2 glacierized area

~ 80,000 km2 frozen ground area

> 3,000 km3 fresh water stored in the glaciers

> 200 million water consumers

Source: Dolgushin, 1989; Gorbunov, 2001; Kotlyakov, 1996

> 1,000,000km2 mountainous area over 1,000 m 45,000 km2 glacierized area

~ 80,000 km2 frozen ground area

> 3,000 km3 fresh water stored in the glaciers

> 200 million water consumers

Source: Dolgushin, 1989; Gorbunov, 2001; Kotlyakov, 1996

Karakorum

80% freshwater originated in mountains40% seasonal snow25% from glaciers~5% from permafrost

MONGOLIA

C H I N A

KAZAKHSTAN

AFGHANISTAN

TURKMENISTAN

UZBEKISTANKYRGYZSTAN

TAJIKISTAN

No glacier – no life in the central Asia dry lands!

No glacier – no life in the central Asia dry lands!

Источник: Фото Л. Браун

winter spring

summer autumn

0

10

20

30

40

50

60

70

80

1936 1942 1948 1954 1960 1966 1972 1978 1984 1990 1996

Altai

Tien Shan

Pamir Takla MakanG o b i

Kara Kum

Kizil Kum

Myuyn Kum

Dasht-e M

argow

Qaidam

50

30

10

1950 1960 1970 1980 1990 2000

Baotou Station

Beijing Station

Total annual number of dust storms observed at ten central Asian stations.

Da

ys

Source: Weihong Qian, et al., JC, 2001

The increase in air temperature can be one of the main factor of dry land and hydrological cycle

instability

Source: Carbon Dioxide Information Analysis Center (CDIAC); Lugina et al. 2000

north of 40N and east of 15E

Northern Eurasia

Annual temperature time seriesLinear trend = 1.2C per 120 years

1881-2002 reference period: 1951-1975

4

3

2

1

0

-1

-2

-3

-41880 1900 1920 1940 1960 1980 2000 2020

Air

tem

pera

ture

, C

-3.0

-4.0

-5.0

-6.0

-7.01940 1960 1980 2000

300

400

500

600

700

800

1940 1960 1980 2000

Ann air temperature, o C

Ann precipitation, mm

-0.8

0

0.8

1.6

1940 1960 1980 2000

-150

-50

50

150

1940 1960 1980 2000

Sibrian Altai (1940-2005, 12 stations): air temperature increased at low elevations more (0.3oC yr-1) than at high elevations (0.01oC yr-1). Precipitation decreased at low elevations and increased at high elevations (3.8mm yr-1), notably in spring months.

Tien Shan (1940-2005, 18 stations): air temperature increased at low elevations (0.02oC yr-1) more

than at high elevations. Precipitation have insignificant increasing trend over the entire Tien Shan.

1960 1980 2000-1.0-0.5

0

1.01.5

0.5

0

500

1000

1940

1940 1960 1980 2000

Pamir (1940-2005, 4 stations): air temperature increased at low elevations (0.03oC yr-1) and 0.01oC yr-1 at high elevations over 3,000m a.s.l. Precipitation increased at low elevations (0.08mm yr -1) and particularly at high elevations of western and central Pamir (8.1mm yr-1), notably in winter months

Snow covered areas by 1,000m isohyps over the Tien Shan for the last twenty years reconstructed by surface observational, AVHRR and MODIS data

Duration of snow melt from the date of maximum snow cover to date of it’s disappearance reduced on 30 days during the last twenty years, equal 138 days in 2007. Snow melt 30 days faster then 20 years ago. The decrease of snow cover is not linear process. Further decrease of snow covered areas may be accelerated due to reduced snow covered area and consequently lesser of heat input necessary for snow melt.

Duration of snow melt from the date of maximum snow cover to date of it’s disappearance reduced on 30 days during the last twenty years, equal 138 days in 2007. Snow melt 30 days faster then 20 years ago. The decrease of snow cover is not linear process. Further decrease of snow covered areas may be accelerated due to reduced snow covered area and consequently lesser of heat input necessary for snow melt.

0

20

40

60

80

snow cover, %

1987 2000 2001 2002 2003 2004 2005 2006 2007199919981997199619951994199319921991199019891988

ten days AVHRR data calibrated with surface observational data eight days MODIS data

-0.5

-0.3

-0.1

0.1

0.3

0.5

Z / M , T C mo

maximum of air temperature gradients

zonal circulation pattern predominates

minimum of air temperature gradients

meridional circulation pattern predominates

zonal

meredional

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990

Indices of circulation patternair temperature gradient

1890 2000

0

Meridional epoch

-20 -15 -10 -5 0 5 10 15 20

0

0

0 +5

0 -5

Interaction between the general circulation of the atmosphere, the meridional gradient of global air temperature, and snow covered area in Eurasia

Interaction between the general circulation of the atmosphere, the meridional gradient of global air temperature, and snow covered area in Eurasia

0

0

Zonal epoch

-40 -20 -10 0 10 20 40

0 +10

0 -10

0

0

A B

Altai, Tien Shan, Pamir, Karakoram and Kunlun are the major mountain ridges of dry central Asia that maintain high volume of snow and ice, the main sources of

water in this region

5.2%

11.1%

4.2%

17.1%

11%

19.2%

Aksiirak glacierized massif

182 glaciers

427 km2 glacierized area

(aerial photogrammetry 1943)

19431977

182 glaciers

406.8 km2 glacierized area

4.2% area reduction

(aerial photogrammetry 1943/1977)

2003

178 glaciers

371.6 km2 glacierized area

8.7% area reduction

(aerial photogrammetry 1977/ASTER 2003)

Akshiirak glacierized massif, Central Tien Shan

Akshiirak glacierized massif, Central Tien Shan

Source: Aizen, and others, AG, 2006

~1800

1869

1943

1956

1977

1995

2002

2007

Petrova Glacier termini, Akshiirak glacierized massif (65.33 km2, from 1869 to 2007 this glacier retreated on 3 km)

Petrova Glacier termini, Akshiirak glacierized massif (65.33 km2, from 1869 to 2007 this glacier retreated on 3 km)

Source: Aizen, and others, AG, 2006

Akshiirak glacial surface change between 1977 and 2000 evaluated by aerial photogrammetry and SRTM data

Akshiirak glacial surface change between 1977 and 2000 evaluated by aerial photogrammetry and SRTM data

Source: Aizen, et al., Annals of Glaciology, 2006

100 m decrease in glacier surface

9.6 km3 ice-volume reduction since 1943

The Tien Shan High Mountains experimental Lidar station. Deviations from long-term average (background) of reverse aerosol scattering coefficients in layer of Stratospheric Aerosol (15-30 km). The background value over central Asia is 1.56 · 10-4.

Altai

1988 1990 1992 1994 1996 1998 2000

10

10

10

10

-2

-3

-4

-5

F cp-1

Pinatubo

Ku

wa

it Ind

iaP

aki

sta

nLo

p

No

r

Lo

p N

or

Aerosols: impact Aerosols: impact

• snow and glacier surface albedo

• change intensity of snow/ice melt and near surface heat exchange

• contaminate atmosphere and water quality

• increase or decrease global air temperature

1955 1960 1965 1970 1975 1980 1985 1990 1995-5

-4

-3

-2

-1

0

1Measured mean annual ground temperatures

CHURAPCHA, 1958-1994

TEM

PER

ATU

RE (°C

)

TIME (years)

0.4 m 0.8 m 1.6 m

Source: Aizen, Marchenko, NSF annual report, 2000

Measured mean annual ground temperatures at different depths at the “Tien Shan” meteorological station (3614 m).

Permafrost: impacts Permafrost: impacts In mountainous areas, thawing permafrost increases risk of landslides and rock falls and has impacts on infrastructure.

Permafrost in Tien Shan has degraded over the past 40 years and is projected to decrease by 20-30% in this century.

glaciers: impactsglaciers: impacts

Shrinkage of glaciers leads to ice instability and formation of ice and debris dams, resulting in more flooding, debris flows ice and avalanches.

-250

-200

-150

-100

-50

0

50

100

150

200

250

-400

-300

-200

-100

0

100

200

300

400

L, cm (Issik Kul, Kukunor, Balkhash, Caspian) L, cm (Lobnor, Aral)

1881 1891 1901 1911 1921 1931 1941 1951 1961 1971 1981

Lobnor

Issik KulKuku Nor

Balkhash

CaspianAral

lakes: impactlakes: impact

Merzbacher Lake Issik Kul Lake Aral Lake

In river basins with small glacierized areas, increase of glacier melt has already led to a decline in river discharge that partly explain the wastage of large Central Asian lakes.

more than one-third of glacial lakes with surface areas between 1 and 5 km2 have disappeared in central Asia

Earlier, synchronous snow and glacier melt changes regime of river runoff causing hydrological instability, spring cloudburst flooding, and protracted period of glacier melt, which temporary increase river discharge but facilitate quick glacier recession.

Earlier, synchronous snow and glacier melt changes regime of river runoff causing hydrological instability, spring cloudburst flooding, and protracted period of glacier melt, which temporary increase river discharge but facilitate quick glacier recession.

0

24

6

8

10

12

1416

Q, m s3 -1

Oct. Nov. Dec. Jan. Feb. Mar. Apr. May Jun Jul. Aug. Sep.

snow peak in 1960- mid 1980th

glacier melt

glacier and snow melt peak since mid 1980th

rivers: impactrivers: impact

Alpine climate and environmental changes impact and consequences

- earlier disappearance of seasonal snow cover, shrunk of the glaciers, and alpine permafrost (particularly from the middle of 1970th)

- increase evaporation accelerate desertification at lowlands intensify of dust storms and aerosol loading to atmosphere increasing near surface heat balance and regional and global air temperatures

- extend snow and glacier ablation period and land-soil instability causes change frequency and magnitude of natural hazards

- change central Asian hydrological cycle

- lack of surface and ground water decrease water quality causes salinization and decline of agricultural production

- increase of mortality rate and people migration.

We need more research and information

• high-elevation meteorological monitoring

• integrative ice-core ground- based and remote sensing data analysis during the last 30 to 50 years

• high-elevation atmospheric dust-aerosol monitoring

• alpine ice-core paleo-climate and environmental analysis

• atmosphere - land surface (alpine terrain) interactive analysis and modeling

GRACIAS