Road Map to Quantify Climate Forcing Road Map to Quantify Climate Forcing Factors on Himalayan GlaciersFactors on Himalayan Glaciers

Baldev R. AroraWadia Institute of Himalayan Geology,DEHRADUN 248 001, IndiaE-mail ID: arorabr@wihg.res.in

Rise of mean annual global surface temperature by 0.74±0.18oC during the last 100 years - Global Warming

Source level increase in anthropogenic emission of carbon-dioxide in atmosphere

Sea level variations

Observable changes in onset and durations of seasons, precipitation pattern, river runoff, variability in biodiversity, etc.

are considered as pointers of changing climate

Climate Change: A reality

1995

1962

Recession of Dokriani glacier over the period 1962-1995

Average rate of recession = 16.5 m/yr

Assessment of Glacier Health by Snout Monitoring

Name of glacier Period years Recession( m)

Average rate(m/yr.)

Milam glacier 1849-1957 108 1350 12.50

Pindari glacier 1845-1966 121 2840 23.40

Gangotri glacier 1962-1991 29 580 20.00

Tipra bank glacier 1960-1986 26 325 12.50

Dokriani glacier 1962-1991 29 480 16.5

Chorabari 1962-2003 41 196 4.8

Shankulpa 1881-1957 76 518 6.8

Poting 1906-1957 51 262 5.13

Glacier No-3Arwa 1932-56 24 198 8.25

Bara Shigri 1956-1963 07 219 31.28

Chhota Shigri 1987-1989 03 54 18.5

Sonapani 1909-1961 52 899 17.2

Kolai 1912-1961 49 800 16.3

Zemu 1977-1984 07 193 27.5

Average Recession Rate of Himalayan Glaciers

Mass-balance studies of Himalayan glaciersS.No.

Name of the glacier

Location Period of study

Cum.Sp.bn. (m)

Worker

12345789101112

Gara glacierGor- GaragShaune GarangNehnarCangmeKhangpuRulung glacierTipra BamakDunagiriChhota-ShigriDokriani glacierChorabari glacier

H.P.H.P.H.P.J&KJ&KJ&KUAUAH.PUAUA

1974-19831977-19851981-19901978-19841978-19871979-19811981-19881984-19921986-19891992-20002003-2003

-2.87-3.30-2.87-2.37-1.86-0.20-1.34-6.26-0.21-1.47-2.70

GSI

GSI

GSI

GSI

GSI

GSI

GSI

GSI

WIHG

WIHG

WIHG

●Shanker R., 1999; Dobhal et al., 1995; Dobhal et. al., 2007; Kaul et al., 1997

AERIAL VIEWDOKRIANI BAMAK GLACIER -BHAGIRATHI BASIN, UTTARAKHAND Din Gad Catchment

Glaciated Area – 7 km2

Catchmnet Area ~ 16 km2

Altitude > 3800 m

Glacier recession

Mass balance

Glacial melt water flow

Glacial sediment transfer

Annual Snout Retreat of Dokriani Glacier 1991-2007

Met Parameter and Snout Recession Trend of Dokriani Glacier-

Annual Average Temp.

Annual Rain Fall (mm)

Standing Snow Depth (mm)

Annual snout Retreat

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

Sn

ow

W.e

q.

(mm

)

1 9 9 8 - 1 9 9 9 1 9 9 9 - 2 0 0 0 2 0 0 0 - 2 0 0 1 2 0 0 1 - 2 0 0 2 2 0 0 2 - 2 0 0 3 2 0 0 3 - 2 0 0 4

S n o w w . e q .

Winter Snow precipitation

Stakes network for mass balance

-3.00-2.00-1.000.001.002.003.004.005.006.00

Vol

mum

e m

illio

n cu

m

1993 1994 1995 1998 1999 2000

year

Comparative Mass-Balance of Dokriani Glacier

Net Accumultion NetAblation Net Balance

Dokriani Glacier, 1992-2000

Period Total Retreat (m)

Annual Snout Recession (ma-1)

Reference

1962-1991 480 16.5 Dobhal et.al. (2004)

1991-2001 161.2 17.8 Dobhal et.al. (2007)

2000-2008 130 16.3 Dobhal & Mehta (2010)

15

15.5

16

16.5

17

17.5

18

Re

ce

ss

ion

m/y

ea

r

1962-1991 1991-2000 2000-2008

Global Warming Factors

• ANTHROPOGRNIC-(Greenhouse Gases, aerosols, dust)

•NATURAL • Solar forcing• Orbital forcing• Radiative forcing

Changes in the Earth's orbit around the Sun (Milankovitch Cycles) are believed to be the pacemaker of the 100,000 year ice age cycle.

AAAA

AA

Long Term Ice Age Cycles of 100 Kyr (Milankovitch Cycles) are attributed to the

eccentricity of the Earth’s orbit around the Sun

Correlation between Solar Irradiance andSunspot Solar cycle during 1978-2004

Do Solar Cycles cause Global Warming?

The global surface temperature, de-trended for Global warming, shows strong correlation with Total Solar Irradiance (TSI)

Forcing from the Sun increases global surface temperature by 0.18o C during the 11-Year Solar Cycle Volcanic eruptions: 1982, 1991 and El-nino Pear 1998

(Source: Charles D. Camp and Ka Kit Tung, 2007)

Dependence of Global Surface Temperature On 11-year Sunspot Solar Cycle

Global measurements of Solar wind pressure by Ulysses Space- craft during 1992-98 (Green Curve) and 2007-2008 (Blue Curve), Scanning respectively the minimum of solar cycles 22 and 23

Solar wind looses power: Hits 50 year low

Solar –Terrestrial implications

Heliosphere inflates less: Less shielding against

the Cosmic Rays

High energy electron (20GeV) in cosmic ray show around 20% increase around the earth

Sun’s magnetic field also decreased by 30% since 1950

(Source: http:// science-nasa.gov/sceince-news/science-at-nasa/nasa/23sep_solarwind/)

Comparison of temperature and density of electrons in solar wind During solar minimum 22 (1994-95) and 23 (2007)

Issautier et al., GRL 35, L19101, doi 10,1029/2008, 2008

Results

No significant change in Solar wind speed : 3%

Solar wind pressure has decreased largely due to decrease in temperature & density

Solar wind Cooler : 13%

Solar wind less dense: 20%

Global measurements of Solar wind pressure by Ulysses Space- craft during 1992-98 (Green Curve) and 2007-2008 (Blue Curve), Scanning respectively the minimum of solar cycles 22 and 23

Solar wind looses power: Hits 50 year low

Solar –Terrestrial implications

Heliosphere inflates less: Less shielding against

the Cosmic Rays

High energy electron (20GeV) in cosmic ray show around 20% increase around the earth

Sun’s magnetic field also decreased by 30% since 1950

(Source: http:// science-nasa.gov/sceince-news/science-at-nasa/nasa/23sep_solarwind/)

The experimental arrangement for tests with diurnal cycles: melting blocks of bare and debris-covered ice exposed to identical radiation during the 12 hour ablation period (attained by two electric bulbs with short-and longwave radiation and cooling by freezer during the 12 hour night

A laboratory experiment to simulate effect of debris cover on melt rate of glacier when subjected to:

(a)Steady state heat flux – Increase in average temperature(b)Diurnally varying heat flux – Day/Night variation in solar radiation

(c)Rainfall together with diurnal thermal forcing

Reznichenko et al., J. Glaciology, 56, 384-396,2010)

Under the effect of fixed increase in heat-flux, i.e in the absence of diurnal variability of radiation, the primary role of debris cover is to delay the onset of steady ice surface melting; once melting rates stabilize, the debris cover has no further significant effect on rate of ablation;

Influence of Debris cover in steady-state (constant increase in heat flux) conditions

Under cyclic diurnal radiation- a reduction in ablation rate occurs, & degree of reduction is controlled by the debris-cover thickness. The effect of rainfall on ice ablation depends both on intensity of diurnal cycle on the permeability of the debris cover: High-permeability supra-glacier - accelerated ablation Rock-avalanche debris - relatively impermeable - reduced ablation rates

Effect of Diurnal Radiation Cycle & Rainfall on Ablation Rate for debris covered ice

Action plan to establish climate forcing factors on glacier dynamics

Establish Flagship Field Stations for multidisciplinary high quality data capture to establish inter-linkages of various forcing factors with glacier dynamics

Document glacial responses to palaeoclimatic variability through laboratory sediment records (moraine, glacial, fluvial and lacustrine), ice cores, peat logs, tree rings etc.

Supplement studies by numerical/laboratory simulation experiments to answer key questions and understand processes controlling climate forcing

Some specific key questions to be answered • Are all the Himalayan glaciers retreating? If so, at what rate?

• Is the glacial retreat affected by Anorthopognic factors or are there Natural Climate Parameters? What are the forcing factors responsible for glacial dynamics in the Himalaya?

• How slope and geometry of the valley control the glacier dynamics? • Is there a difference in the rates of retreat between larger and the smaller

glaciers? If so, why and How much?

• Does the valley orientation (direction) have any bearing on the magnitude of response (retreat)? What is the magnitude of change?

• Whether the moraine cover protect the glaciers from incoming solar radiation? Can this be quantified?

• Whether the Proxies like Snow line and/or Tree line fluctuations in Himalaya marker of climate variation?

Thank you