Future projection of extreme events

While broad aspects of Asian climate change show consistency among AOGCM simulations, a number of sources of uncertainty remain. It is also likely that some local climate changes will vary significantly from regional trends due to the region's very complex topography and marine influences in the region. From these reasons, there has been little assessment of the projected changes in regional climate means and extremes in the Asia region. We examine the regional characteristics of extreme changes over the Asia-Pacific region, with focus on the investigations on the factors determining the regional characteristics. In addition, based on the projections of regional changes in climate extremes, the impacts of climate change on the economic sector in the Asia-Pacific region are investigated.

Decadal prediction and variability

The new field of climate predictions focuses on the "decadal" (defined as 10 to 30 years in the future) time scale that is of great interest to policymakers and stakeholders at present. So, there have been several efforts at decadal prediction using initialized global coupled climate models though general climate predictions have been narrowly confined within seasonal to interannual time scales so far. To illuminate a potential predictability covering more than decadal time scale, the Pacific decadal Oscillation (PDO), a well-known decadal-scale sea surface temperature oscillation mode which shifts every 20 to 30 years over the Pacific Ocean, is one of the important components in the Pacific Ocean. Therefore, in APCC, relevant studies to realize the decadal prediction over APEC region are now underway using the decadally-changing PDO variability.

Climate system feedback (cloud, aerosol)

Cloud have conflicting effect on the earth's radiation, the albedo effect and the greenhouse effect. The balance between these two effects depends on many factors, including marcrophysical and microphysical cloud properties. In the current climate, cloud exerts a cooling effect on climate (the global mean cloud radiative forcing is negative). In response to global warming, the cooling effect of clouds on climate might be enhanced or weakened, thereby producing a radiative feedback to climate warming. Aerosols can affect climate directly by absorbing or reflecting radiation. They can also influence the climate indirectly by seeding clouds that affect the amount of solar radiation reaching the Earth. The net effect of aerosols is estimated to be equivalent to a radiative forcing of roughly -1.2 W/m2, in comparison to the overall average CO2 forcing of +1.66 W/m2. To understand climate system feedback, variations in cloud cover (aerosol) as well as relationship between cloud cover (aerosol) and other variables are examined using observational satellite data and Intergovernmental panel on climate change (IPCC) Fourth Assessment Report (AR4) models.

Water Balance changes

We investigate the water balance change in macro-scale region and also estimate the surface runoff in the Asia-Pacific region using the space-borne Tropical Rainfall Measuring Mission (TRMM) precipitation radar and multi-satellite microwave imager (AQUA, NOAA, DMSP) to train the microwave radiometer to retrieve rainfall.