COASTAL ICE CORE RECORDS ON ENVIRONMENTAL CHANGES IN ANTARCTICA: RESULTS FROM INDIAN ITASE

1
COASTAL ICE CORE RECORDS ON ENVIRONMENTAL CHANGES
IN ANTARCTICA RESULTS FROM INDIAN ITASE

• Thamban Meloth
• National Centre for Antarctic Ocean Research
• Ministry of Earth Sciences (Govt. of India)
• Vasco-da-Gama, GOA 403 804

Website www.ncaor.gov.in ltgt E-mail
meloth_at_ncaor.org
2
Oceans Poles
Southern (water) hemisphere 91 water
coverage Antarctica 70 of worlds freshwater
Northern (land) hemisphere51 water coverage
http//oceancolor.gsfc.nasa.gov/cgi/biosphere_glob
es.pl
3
Maitri (1989)
D.Gangotri (1983-90)
At Larsemann Hills 20xx
INDIA IN ANATARCTICA
4
Poles are no longer poles apart!
One-to-one coupling of glacial climate
variability in Greenland and Antarctica (EPICA
Members, 2006)
5
Ice core vs. Instrumental temperature data.
Influence of SAM on Antarctic temperature
(Schneider et al., 2006)
6
INDIAN INITIATIVES ITASE
Indian ITASE concentrates along a coastal to
inland transect in the central Dronning Maud Land
7

• SCIENTIFIC QUESTIONS?
• How did the coastal Antarctic environment
  respond to the changes in global climate as well
  as to extreme events such as volcanic eruptions
  during the past?
• How did the climatic teleconnections
  influenced the atmospheric chemistry of coastal
  Antarctica as recorded in snow?
• What are the spatial variations and its causes
  within the temporal records from different
  locations in Antarctica?
• What was the role of external and/or internal
  forcing mechanisms on the Antarctic environment?

8
STUDY AREA
ANTARCTICA
Central Dronning Maud Land
Ingrid Christensen Coast
9
RECENT FIELD CAMPAIGNS IN EAST ANTARCTICA
ICE CORE DRILLING coastal Dronning Maud Land
? IND-25/B5 Lat. 71 20.5 S Long. 11 35.6
E (25th InSEA) ? IND-26/B6 Lat. 70º 11.4 S
Long. 12º 27.1 E (26th InSEA) ? IND-26/B7
Lat 70º 13.8 S Long. 11º 55.7 E (26th InSEA)
SNOW SAMPLING Ingrid Christensen Coast ?
LARSEMANN TRANSECT ? PUBLICATIONS ICE SHELF
TRANSECT ? AMERY ICE SHELF TRANSECT
10
FIELD ACTIVITIES 2006-07
11
LABORATORY ACTIVITIES
12

• Ice cores as archives of past volcanic events

Core IND-22/B4
Thamban et al., 2006 Curr. Science
13
Micro-particles in ice significance
Ice-melts were filtered in the CLASS 100 room
scanned using SEM-EDS.
Core IND-22/B4
Laluraj et al., 2008 ENV. MON. ASSESS
14
Microbial cells adhered to micro-tephra
Laluraj et al., 2008 ENV. MON. ASSESS
Core IND-22/B4
15

• Solar forcing on Antarctic chemistry change?

Core IND-25/B5
16
High-resolution stable isotope studies
Core IND-25/B5
17
Relation between ice core ?18O El Niño ?
Naik et al., 2008 Gcubed- under review
Core IND-25/B5
18
Combined effect of ENSO AAO on ?18O
temperature?
Core IND-25/B5
Naik et al., 2008 Gcubed- under review
19
Snow accumulation rate ?18O
Core IND-25/B5
20
Deuterium excess Shift in moisture source
21
SURFACE SNOW STUDIES ALONG INGRID CHRISTENSEN
COAST
22
FRACTIONATION OF SULPHUR COMPONENTS IN SNOW
(nssSO42-) (SO42-) - 0.252 (Na)
Thamban et al., 2008, Under Review, Appl. Geochem.
23
FROST FLOWER FORMATION FRACTIONATION
(nssSO42-) (SO42-) - 0.252 (Na)
Thamban et al., 2008, Under Review, Appl. Geochem.
24
BIOLOGICAL CONTRIBUTION TO SNOW AEROSOL CHEMISTRY
(nssSO42-) (SO42-) - 0.252 (Na)
Antony et al., Under Review, GRL
Thamban et al., 2008
25
SNOW BIOGEOCHEMISTRY CLIMATE LINKAGE
(nssSO42-) (SO42-) - 0.252 (Na)
Antony et al., Under Review, GRL
26

• IMPORTANT FINDINGS
• Shallow ice cores from coastal Antarctica provide
  light on the spatial and temporal variations in
  the climate and environment.
• Large volcanic events associated with anomalous
  sulphate peaks also reveal presence of
  micro-tephra. Some of these particles harbor
  microbial cells adhered to surfaces, supporting a
  significant micro-niche in accreted ice, hitherto
  unknown.
• High-resolution ice core studies in relation to
  instrumental data also reveal that the coastal
  Antarctic climate and snow accumulation is
  influenced by the combined ENSO and AAO forcings.
  
• Coastal Ice core data is also seems to support
  the influence of solar forcing on Antarctic
  environment.
• Surface snow samples from coastal region provide
  vital clues on biogeochemical cycling of sulphur
  and nitrogen and atmospheric budget.

27

• FUTURE OUTLOOK
• The Indian program envisages increased activities
  to obtain more cores under the ITASE program.
• More efforts are also being made to obtain ice
  cores that record 2000 years of climate/
  environmental change. The 2K represent- Natural
  (MWP) anthropogenic (20th Century) warming
  important for climate modeling sub-annual
  resolution possible
• Asian collaboration is also warming up under the
  aegis of Asian Forum on Polar Sciences (AFoPS -
  China, India, Japan, Korea Malaysia). AFoPS may
  conduct a collaborative shallow ice core project
  in in Arctic too.
• Increased collaboration in field and science with
  ITASE partners?

28
Thanks!