Effect of Climate Change on the variability of snow and glacier melt

Wadia Institute of Himalayan GeologyDehra Dun

Indo- European Co-operation on climate Research and Innovation, 28 November 2011, New Delhi

Prof. Anil K. Gupta and Dr. D.P. Dobhal

Climate change and Glacier systems

• Snow /glaciers integrates climaticvariations on different time and spatialscales

• Glaciers most visibly represent climatechange and climate variability.

• Hence at the centre of present concernsand raging debate

Climate variability and Glacier-Regime in Indian Himalayan Region (IHR)

Winter Snow

WD + Monsoon

Monsoon

Geographical Area 5.3x105 km2

Extending over 2500 km between NE and NW

Broadly divided in to three climatic Zone

WD

•70% of world’s fresh water is frozen in glaciers•Himalayan glaciers feed three great river systems of North India•30-40% of river runoff is derived from these glaciers

Indian Himalayan Glacier SystemIndian Himalayan Glacier System

State Glaciers Area (km2) Average Size (km2) Glacier%J&K 5262 29163 10. 24 61.8Himachal 2735 4516 3.35 8.1Uttarakhand 968 2857 3. 87 18.1Sikkim 449 706 1.50 8.7Arunachal 162 223 1.40 3.2

Jammu & Kashmir

Himachal

Uttarakhand

Sikkim

Number of glaciers - ~ 9575Glacierized area - 37465km2

Total ice volume - 142.88km3

(Source: GSI,2009

• Third largest glacier system on the Earth

• 9575glaciers occupying an area of 37465 km2

• Distribution of glaciers uneven from East to West (altitude, latitude, precipitation, aspect)

• Maximum concentration of glaciers in NW Himalaya

• Length of glaciers varies from 1-72 km

• Glaciers extend between altitude 3700 to 6000 m

• Snow line (ELA) altitudes: 4100 m in Kashmir, 4800 m in Himachal, 5050 m in Garhwal and 5300 m in Sikkim

Himalayan glaciers – At a Glance

The Scientific Concerns (Gaps)

Are Himalayan glaciers Melting fast?

What is the contribution of Himalayan glaciers to the Himalayan rivers ?

How is the Indian monsoon system responding to these changes?

Role of Forcing factors: Solar insolation and sun spot activity (that drives land-sea thermal contrast) on snow and albedo, ENSO,

What should be the observational strategies to capture these forcings, measure changes?

1962 – 1995 – 550m (16.6m/yr) 1995 – 2010 – 260m (17.3 m/yr)

1962 - 2010 = 810 m (16.8 ma-1)

The snout of the glacier is a best marker of its advancement and recession over the period of few years and decades.

Frontal Retreat in Glaciers

2010

1962

Recession of Dokriani Glacier- 1962 to 2010

1995

Annual Snout Retreat of Dokriani Glacier 1991-2008

Snout Recession trends of Himalayan GlaciersSnout Recession trends of Himalayan Glaciers

Source: GSI, WIHG

0

5

10

15

20

25

30

35

40

Sno

ut R

etre

at (m

/yea

r)

1935-1956 1956-1971 1971-1974 1974-1975 1975-1976 1976-1977 1977-1990 1990-1996

Gangotri Glacier

0

510

15

2025

30

35

Snou

t Ret

reat

(m/y

ear)

1849-1906 1906-1938 1938-1957 1957-1966 1966-1997

Milam Glacier

0

5

10

15

20

25

Rec

essi

on (m

/yea

r)

1960-1987 1987-2002 2002-2006

0

5

10

15

20

25

Snou

t Ret

reat

(m/y

ear)

1962-1990 2005-20060

5

10

15

20

25

30

Snou

t Ret

reat

(m/y

ear)

1845-1906 1906-1958 1958-1966

Pindari GlacierJoundhar Glacier

Satopanth Glacier

Chhota Shigri Glacier

0

2

4

6

8

10

12

Snou

t Ret

rate

(m/y

ear)

1960-1990 1990-2003 2003-2004 2004-2005 2005-2006 2006-2007

14.5

15

15.5

16

16.5

17

17.5

18

Rec

essi

on m

/yea

r

1962-1991 1991-2000 2000-2007

Dokriani GlacierChorabari Glacier

0

5

10

15

20

25

Rec

essi

on (m

/yea

r)

1960-1987 1987-2002 2002-2006

Tipra glacier

Recession Trends of Glaciers in Himalaya (NW-NE)Recession Trends of Glaciers in Himalaya (NW-NE)

(Source: GSI, WIHG & ICIMOD)

Rates of glacier retreat vary considerably; a few glaciers have retreated with an average rate of 18 to 20 m/year, while few show less retreat rate (<10 m/year Like; Chorabari and Bhagirath Kharak glaciers etc

Snout Recession Trend of some Himalayan Glaciers

It is estimated that there is no much changes in trend but magnitude of retreating rate is changed.

Kedarnath Town just below the Chorabari Glacier, source of Mandakini River

Past retreating scenario of Himalayan Glacier-Chorabari Glacier in Uttarakhand

The lichenometry study (relative dating) forreconstruction of the past glacier's retreating rate alsosupports that the retreating rate of Chorabari (5.5m/yr)was less than the Dokriani glacier (10.8m/yr) during thelast stage of advance and retreat

S.No.

Name of the glacier Location Period ofstudy

Cum.Sp.Bn.(m)

Worker

123456789

10

11

Gara glacierGor- GaragShaune GarangNehnarCangme KhangpuRulung glacierTipra BamakDunagiriChhota-Shigri

Dokriani glacier

Chorabari glacier

H.P.H.P.H.P.J&KJ&KJ&KUKUKH.P

UK

UK

1974-19831977-19851981-19901978-19841978-19871979-19811981-19881984-19921986-19892002-2001992-cont.-2007-cont.2003-2010

-2.87-3.30-2.87-2.37-1.86-0.20-1.34-6.26-0.21

-1.47

-1.75

GSIGSIGSIGSIGSIGSIGSIGSIWIHG/JNUWIHG

WIHG

Mass-balance of Himalayan glaciers

Mass balance Trend of Himalayan Glaciers

Location of the Glaciers

1

1

2-4

2

5-8 4

5

6

3

7

8

Variable Retreating trend of Himalayan Glaciers,

-0.42-0.44 -0.45

-0.79

-0.75

-0.65 -0.66

-0.74

-0.9

-0.8

-0.7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0

2005

-06

2006

-07

2007

-08

2008

-09

2009

-10

Mas

s ba

lanc

e m

w.e

.

Dokriani Chorabari

`

`

• The studies carried out on Dokriani (7km2) and Chorabari (6.4km2) glaciers in Central Himalaya shows that both glaciers are retreating and having negative mass balance trend. The most interesting results are;

• Dokriani glacier is retreating with average rate of 18.5m/yr (3910m), where as the Chorabari glacier has just half of the Dokriani and is 9.5m/yr (3860m), But

• Mass balance is just reverse of the snout retreat i.e. for Chorabari glacier 0.77m w.e.a-1

(ELA, 5060m) is almost double compared to the Dokriani Glacier i.e 0.43 m w.e a-1 (ELA 5040m) during the study period.

The study shows that Temperature is not only forcing factor to retreat the glaciers but topographic

and morphological factors equally play important role to control glacial melt. The annual fluctuation in recession may be due to variable winter snowfalls. The study still continues to evaluate the change in glacier mass and dynamic

processes vis-a vis climate change .

Ice surface lowering (Volume loss) in Dokriani glacier during a period of 13 years

i) Rapid surface thinningii) Decrease of snow cover (transition snowline)iii) Increase of debris cover in lower ablation area

Longitudinal profiles along the central line showing the surface elevationchanges in Dokriani glacier during the period 1962-1995 and 1995-2007

Changes in surface elevation on Dokriani Glacier

Glacier shrinkage at higher altitudes

SUPRA GLACIAL LAKES IN ABLATION ZONE

Small glaciers are more prone to melting

AVERAGE SNOW COVERED AREA IN DIFFERENT HIMALAYAN BASINS

Chenab Basin 22200 15590 (70%) 5400 (24%)up to Akhnoor

Ganga Basin 19700 9080 (46%) 3800 (19%)up to Devprayag

Satluj Basin 22275 14498 (65%) 4528 (20%)up to Bhakra Dam

Beas Basin 5278 2700 (51%) 780 (14%)up to Pandoh Dam

(Source: NIH)

Basin Total Area Max. SCA Min. SCA(km2) (km2) (km2)

SNOW AND GLACIER MELT RUNOFF IN DIFFERENT HIMALAYAN BASINS

SNOW AND GLACIER MELT RUNOFF IN DIFFERENT HIMALAYAN BASINS

Chenab River Akhnoor 49%

Satluj River Bhakra Dam 60% (Indian part)

Ganga River Devprayag 30%

River Site Av. snow & glaciers melt contribution to

annual flows

(Source: NIH)

0

100

200

300

400

500Di

scha

rge

F lux

(10

4m

3 )

May June July August September October November

- 43 x106 m3

- 94 x106 m 3

- 217 x106 m3

Discharge Flux- at different area

Glacierised

Pro -glacial

Non Glacierised

Early springSnow+ rain

SummerSnow +Ice+ monsoon rain

AutumnIce + rain

Contribution of Snow/ice melt water discharge from glacierised area

Contribution of Snow/ice melt water discharge from glacierised area

0

20

40

60

80

100

120

1-Apr 1-May 31-May 30-Jun 30-Jul 29-Aug 28-Sep 28-Oct 27-Nov

Disc

harg

e (m

3 X 1

04 / d

ay)

1998 1999

2000 2001

2002 2003

2004 2005

2006 2007

2008 2009

Discharge Fluctuations- Dokriani Glacier, 1998 - 2009

0

100

200

300

400

500

600

Snow

W.e

q. (m

m)

1998-1999 1999-2000 2000-2001 2001-2002 2002-2003 2003-2004

Snow w.eq.

Winter snow precipitation has higher inter annual variability than monsoon rainfall

Winter snow precipitation has higher inter annual variability than monsoon rainfall

0

200

400

600

800

1000

12001400

1600

1800

Rain

fall

(mm

)

Tela Gujjar SnoutStatio ns

Yearly Rainfall Variations

1998

1999

2000

2001

2003

2004

Forcing factors for driving century to millennial scale changes in the Indian monsoon

• Solar insolation and sun spot activity (strengthening land-sea thermal contrast)

• Himalayan snow and albedo• Walker Circulation and ENSO• Indian Ocean Dipole

H.F. Blanford first time suggested that Himalayan snow cover influences monsoon circulation (in the year following the great

famine of 1877)

Himalayan Snow

Influences of monsoon circulation

Albedo feedback and changes

80 - 90% 40-50 %

LessSnow

LowerAlbedo

MoreEnergy

WarmerTemp.

Out of total glaciers (9575), 60-70% glacier are lessthan 5 km2 and are debris covered

Snout recession rate fluctuating between 05 and 20m/yr

BUT

Rate of recession in different glacier is found to bevariable in different years

This variable rate of recession can be attributedto winter precipitation

SummarySummary

No significant relationship observed betweentemperature and snout retreat rate

But

More melting than accumulation results indisequilibrium in glacier health (mass balance)

And

Summer period expended and winter shrink,consequence less winter snow accumulation

Centre for glaciology was set up in July 2009. It is envisaged to under- take research on Himalayan glaciology and coordinate and initiatethe interactions with all the working institutions and scientists in thevarious glaciological studies, which have come to the fore during thelast project.

New Initiations

Established a Centre for Glaciology at WIHG, under the HimalayanGlaciological Research Programme of Dept. of Science and Technology.Govt. of India, New Delhi

Proposed Glaciers for Long & short term Monitoring

Flagship Field station for Glacier MonitoringFlagship Field station for Glacier Monitoring

Institutional Linkages

Automatic Weather station (AWS) Network at Dokriani Glacier Catchment

Automatic Weather station (AWS) Network at Chorabari Glacier Catchment

Rambara, 2760m asl Base Camp 3820m asl Glacier camp 4270m asl