For several years, global warming has been discussed in terms of its various influences on human society and a wide range of countermeasures have been actively promoted. Recently, the interest on impact evaluation has shifted from the entire global domain to particular countries or regional societies. Regional influences of the global warming often manifest themselves as the noticeable modulations of natural climate variability. In this respect, APL’s activities are closely and directly related to our real life events not in a distant future but in the present or several months ahead. APL’s activities are expected to contribute to the various fields of human activities indicated here which may be influenced by the ongoing global warming.
According to the report of the World Meteorological Organization (WMO), trillions of dollars worth of assets and thousands of human lives are saved globally every year by daily weather forecasting. Many of the extreme weather phenomena responsible for disasters are closely connected to climate variations. The variation in wheat production in Australia is a typical case (Lower row left). The progression of global warming tends to influence climate patterns. Thus, forecasting changing climate variability patterns has a substantial social benefit for protecting human lives and assets.
El Nino, often mentioned in association with abnormal weather patterns, is a well-known and significant phenomenon in the tropical Pacific Ocean. Although the Indian Ocean had been considered as an inactive ocean, El Nino like phenomenon called the “Indian Ocean Dipole Phenomenon” (IOD) was discovered about a decade ago. The frequency with which IOD occur seems to increase recently probably due to the ongoing global warming. On the other hand, El Nino tends to emerge with a slightly different pattern, called “El Nino Modoki” , which may also be a result of global warming. Those two new phenomena were discovered by the research activities done in the parent body of the present APL. Advanced forecasting research has since been carried on and developed further by future APL activities.
Although El Nino and IOD are phenomena that occur over the oceans, both of which largely influence the global atmospheric flow pattern through their associated anomalous sea surface temperature field. The oceanic influence thus exerted on the lower boundary of the atmosphere propagates in the form of characteristic atmospheric wave patterns horizontally as well as vertically and eventually reaches the regions quite far from the original location of the phenomena. This mechanism is referred to as “Teleconnection” and it provides important information for people living across the globe. The right figure shows the unique teleconnection patterns respectively related to IOD and El Nino.
The Application Laboratory has been developing an advanced coupled model, which we call Multi-Scale Simulator for the Geoenvironment (MSSG), with the Earth Simulator Center. MSSG is composed of a non-hydrostatic atmosphere general circulation model coupled to a land model, a non-hydrostatic/hydrostatic ocean model, and an ocean wave model with high performance computing architectures on the Earth Simulator. MSSG has been designed to simulate various multi-scale multi-physics phenomena of the Earth system in a seamless way. It serves a key concept of our understanding of the complex, multi-scale interactions with an aim to advance prediction of weather and climate variability. Especially, MSSG will provide us the prediction and understanding how our imminent environment would be influenced by El Nino or Indian Ocean Dipole and how changed extremes would be making in response to the global warming.