Warming in the polar regions and its implications to Malaysia.

Azizan Abu Samah

(I would like to acknowledge that some of the slides were taken from the talk by Dr Turner

and Dr Stoddart at the MISA 3 and ICSU (ROAP)-SCAR forum on Impact of Rapid Polar

Warming and others from the IPCC and NOAA)

Climate Change 2007: The Physical Science Basis

Forum: Understanding the Implications of Rapid Warming in the Polar Regions on

Earth SystemsKota Kinabula, 23 March, 2007

Changes in greenhouse gases aerosols, solar radiation and land surface properties alter the energy balance of the climate system. Radiative forcing is used to compare how human and natural factors drive warming or cooling influences on global climate. (2)

The globally averaged net effect of human activities since 1750 has been one of warming.

Carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 due primarily to fossil fuel use and land-use change. (1)

Warming of the climate system is unequivocal as evidenced by increases in global average temperatures, melting of snow and ice, and rising global average sea level.

Paleoclimate information supports the interpretation that the warmth of the last half century is unusual in at least the previous 1300 years.

Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.

Continued emissions would cause further warming and changes in the global climate system during the 21st century larger during the 20th century.

There is now higher confidence in projected patterns of warming, winds pattern, precipitation, extremes and ice.

Anthropogenic warming and sea level rise would continue for centuries even if greenhouse gas concentrations were to be stabilized.

Observed global warming.

• Observed Global Land Temperature Trend.

• The three hot spots of rapid polar

warming:

• Alaska

• Siberia

• Peninsular Antarctica

Surface Temperature Changes

Global annual combined land surface air temperature and SST (°C) (red) relative to the 1961–1990 mean. The blue line reflects decadal smoothing. (IPCC)

From Hansen et al. (1999)

Natural Climatic Variability and Simulation of Sea Ice Retreat in the

Arctic.

• The Arctic Oscillation (AO) and Northern Hemisphere Annular Mode (NAM)

• The Pacific Decadal Oscillation (PDO)

• Comparison of Observation of Sea Ice Retreat with models simulation.

• A model prediction of sea ice retreat for 1985 and 2085.

Courtesy LDEO, Columbia Univ.

The North Atlantic Oscillation(NAO) and the

Northern Hemisphere Annular Mode (NAM)

Positive Phase Negative Phase

The Arctic Oscillation in Winter

From Turner et al., 2006 Int J Climatol

The Siberian Warming

Peterson et al, 2002

Discharge from the 6 largest Eurasian rivers has increased by 7% between 1936 and 1999, equivalent to an increase from 0.058 to 0.062 Sv

Barrow1.7°C

Bettles2.3°C

Fairbanks2.1°C

Big Delta1.8°C

Kotzebue1.5°C

Nome1.5°C

Bethel2.1°C

McGrath2.1°C

Anchorage1.9°C Yakutat

1.4°C

Annette1.2°C

King Salmon2.4°C

Cold Bay1.0°C

St Paul1.1°C

Gulkana1.6°C

Talkeetna2.7°C

Homer2.3°C

Total Change1949 - 2003

Juneau1.9°C

The Alaskan Warming

Statewide Temperature Departure and PDO

(°C)

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Impact on the sea ice

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Observed summer sea ice extent 2006

Model Simulation of Sea Ice for 1985

Model simulation for sea ice 2085

Warming of the Antarctic Peninsular.

• Observed warming.

• Influence of the Southern Annular Mode (SAM)

Faraday Winter Temperature and Ice Concentration

to the West of the Peninsula

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Temp Conc

The Southern Annular Mode (SAM)The Southern Annular Mode (SAM)

Source: Todd Mitchell (http://tao.atmos.washington.edu/aao/)

• The principal mode of variability inthe atmospheric circulation of the Southern Hemisphere (SH).

• Also known as the:High Latitude ModeAntarctic Oscillation

• Synchronous anomalies of oppositesign in Antarctica and the mid-latitudes: ‘see-saw’.

• Equivalent barotropic: revealed as the leading EOF in different atmospheric fields throughout thetroposphere and lower stratosphere.

• The SAM can be taken as thedifference in mean sea levelpressure between 40 and 65S

Recent Changes in the SAMRecent Changes in the SAM

Seasonal values of the SAM derived from observations (bar chart) withannual values overlain as the black line

Increasing Flow Over the Antarctic Peninsula During the Summer Leading to

Loss of the Ice Shelves as the SAM has Shifted into it’s Positive Phase

Divergence of model simulations• Winter surface

(skin) temperature linear trend: last 50 years

• Large model spread

Dr.Turner Conclude

• There have been widespread increases of temperature, loss of permafrost and a reduction in sea ice in the Arctic during recent decades

• The major surface changes in the Antarctic have been confined to the Antarctic Peninsula

• Strong climate system interactions and feedbacks complicate the separation of natural variability and the effects of Man’s activity

• Modes of climate variability, such as the NAO and the PDO are extremely important in influencing regional climate change

Conclusion II

• The shift of the NAO/AO into it’s positive phase has certainly played a role in the Siberian warming

• The eastern Antarctic Peninsula changes have been a result of increasing westerly winds

• The warming on the western side of the Peninsula has been a result of a decrease in sea ice, although the reasons for this are unknown at present

• Predictions for the next century suggest increasing temperatures, greater precipitation and a loss of snow cover and permafrost

Currently rising at about 3 mm per year50% from thermal expansion of the ocean25% from glaciers and ice caps7% from Greenland7% from Antarctica

We expect to see a 20-50 cm rise in sea level over next century under sresa1b scenario.The range of scenarios extent from 20 – 60 cm.Assuming the current rate of ice discharge from Antarctica“Net loss of ice mass could occur if dynamical ice discharge dominates the ice sheet mass balance” – IPCC 2007

Sea Level Rise

Oceanographic Changes – Antarctic Bottom Water

• Antarctic Bottom Water is the densest water mass in the world’s ocean and plays a major role in the global ocean circulation

• Loss of sea ice and ice shelves may result in less production of AABW, with consequent global impacts

Ocean acidification occurs when CO2 absorption levels increase and lower the pH

In Southern Ocean aragonite is unstable at 500ppm CO2. Critical point is 600ppm CO2 currently 380ppm

Evidence of Cretaceous marine extinctions when CO2 levels were last at high levels of CO2

Changes to the calcification rate of

corals

Looking at the variation of monsoon onset associated with ENSO as a proxy of possible

impact of climate change to Malaysia.

• Use of 850 mb wind to determine onset of monsoon.

The mean annual 850 mb wind over Malaysia

Peninsular Malaysia (850 kPa wind) – Showing on set of South West Monsoon and Northeast Monsoon

North Borneo (i.e. Sarawak and Sabah of East Malaysia)

Figure 5: Time-latitude distribution of the climatological (1971 – 2000) pentad mean 850 hPa winds (ms-1) averaged between 97o E and 108o E (for Peninsular Malaysia, top) and between 108o E and 120o E (for East Malaysia, bottom). The zero contour line separates winds having easterly and westerly components.

Variation of Onset Dates of the Monsoon with SOI.

• Note the delay of the SW monsoon.

• Earlier onset of the Northeast Monsoon during ENSO periods.

Figure 10: Annual variations of onset dates of southwest monsoon (open circle, bottom) and northeast monsoon (dark circle, top) in Malaysia. The horizontal lines are the mean onset dates of the respective monsoons while the vertical lines indicate significant El Nino years.

Figure 11: Monthly variations of Southern Oscillation Index from 1971 to 2005 (Source: US Climate Prediction Center) .

Correlation Coefficient

Southwest Monsoon

-0.35

Northeast Monsoon

0 .37

(a JJA)

(b ENSO ANOMALY)

c- ND (NE Onset) d ENSO Anomaly

e Jan- Feb f

Figure 13: Composite (1979 – 1998) 850 hPa winds (m/s) and selected olr (shaded, w/m^2) contour levels for (a) June-July-August, (c) November-December, (e) January-February and their anomalies (olr shown as contours here) during significant El Nino years (1982/83, 1991/92, 1994/95, and 1997/98) for (b) June-July-August, (d) November-December and (f) January-February. [Note: 1986/87 El Nino is excluded as it commenced in November 1986 and ended in September 1987.]

(a) Normal

ENSO

Figure 16(i) : Composite (1979 – 1998) Walker Circulations (m/s, averaged between 2.5 S and 7.5 N) for June-July-August (a) during normal year and (b) , during significant El Nino years (1982/83, 1991/92, 1994/95, and 1997/98). [Note: Solid lines are streamlines.]

What can be concluded from this proxy study ?

1. The effect of topography is very important. Hence research effort in downscaling2. The response to the change brought by the ENSO that influence our climate is a) Inter-hemispheric covering the subtropical high of both hemisphere. b) The tropical Indian Ocean and the Pacific Ocean plays an important role. We need to know more about the Pacific Decadal Oscillation (PDO) and the Indian Ocean Dipole.c) The monsoon response to the ENSO perturbation is complex.

3. We need to increase effort in downscaling our climate change model from global to regional.

4. We need to research on how the warming of Siberia and PDO effect our monsoon.

What effects of rapid polar warming can impact on Malaysia

• The decrease in sea ice will open the Arctic to new navigation routes, resource exploitation and ecosystem changes.

• The thermohaline oceanic may change and may impact on nutrient transport and fisheries in our region.

• Predicted moderate sea level rise may also impact on our coastal resources.

• Increase acidification of the ocean may impact on our corals and marine ecosystem.

Akal sama dipintal,

Daya sama di cuba.

Berat sama dipikul,

Ringan sama dijinjing.

Thank you