Introduce: Professor

Meteorology and climate dynamics, our research subject, is getting more important in the 21th century. Recently, it is not too much to say that no day is passed but the extreme weather, global warming, and so on, are covered by the mass media every day. The demand of society for the meteorology and climate dynamics is growing, from the viewpoint of industry and economy, as well as natural environment and disaster prevention.

This is because the meteorology and climate dynamics are natural sciences based on laws of physics, and then able to predict numerically future weather or climate based on the current observational data, with considerable certainty. Daily weather forecasting provides information indispensable to protect our lives from natural disaster, such as torrential rain; seasonal forecasting does that instrumental in various industrial fields, such as agricultural, energy, tourist and insurance industry; climate change prediction does understandings on which policy decision is based, which may determine our future.

It is vital for the weather forecasting and climate prediction that sufficient observational data to grasp atmospheric and oceanic situations and plentiful computational resources. These observed data and predicted data by numerical models are quite useful for researches of meteorology and climate dynamics, whose goal is to understand the mechanism of atmospheric circulation, temperature distribution, and formation/variation of cloud-precipitation system, and to interpret their possible change in future. Nowadays, associated with rapid improvement of computational science, researches become more and more important, which utilize high-resolution or long-term simulations with numerical climate models, taking advantage of the plentiful computational resources, and new observational data in atmosphere and ocean based on satellite measurement, and furthermore, long-term atmospheric data in the past several decades.

Introduce: Associate Professor

Earth’s atmosphere and ocean mutually interact and form the climate system. Lives have evolved and are distributed in adapting to climate. Human beings also have developed society and culture depending on climate. Climate is not stationary but fluctuates. Such fluctuations have influenced human history, such as Great Barbarian Invasion and the French Revolution.
Climate fluctuates due to two processes. First, it responds to external forcing that is imposed from outside of the climate system, such as volcanic eruptions, change of solar activity, and atmospheric composition changes due to industry. “Climate change” refers to such forced response of climate system that occurs in multidecadal and longer time scales. The ongoing global warming is the most recognized example of climate change. The second type of climate fluctuations is called “climate variability”, which arises internally due to chaotic behavior of the climate system. Several modes of climate variability have been identified, with characteristic spatial structures and time scales ranging from days to decades. It is a superposition of the climate change and variability modes that we observe as abnormal and extreme weather. Different mechanisms are operative behind climate change and variability, but what we can observe is a mixture of them. Theories and statistical analysis are thus crucial to unravel mechanisms of climate fluctuations.
Circulation of atmosphere and ocean and their interaction are origins of climate variability. Circulation is also essential for structure and seasonality of climate change; temperature is projected to increase almost everywhere on the Earth’s surface under the global warming, whereas precipitation will either increase or decrease depending on regions and seasons. The circulation change must be involved in such pattern formation. Focusing on the circulation and interaction of the atmosphere and ocean, our research group pursues understanding of formation of present and past climate and mechanisms and interplay of climate variability and change. Our ingredients are observational data and numerical simulations by climate models. Various physical quantities, many with 3-dimensional distributions and sometimes reaching hundreds of years, amount to a huge size of data. By utilizing of statistical technics and accumulated knowledge, we extract climate phenomena to study mechanisms and predictability of them.
Understanding the climate system goes beyond just scientific interests. Its societal significance is growing due to its applicability to other research fields and influence on policy making; understanding mechanisms of extreme weather can lead to improved prediction, and quantification of greenhouse gas-induced climate change, which serves as a guide to energy policy, needs a mechanism-based validation. Climate dynamics is a basic science that is rooted in physical laws, but at the same time, has an aspect of applied science directly tied to our lives.

Interests

Our goal is to understand atmospheric and climate dynamics in the extratropics by performing data analysis and conducting numerical experiments.
Examples of our research topics are as follows:

Blocking high

Siberian high

Okhotsk high

PJ pattern

Silk road pattern

Storm tracks

Stratospheric planetary waves

Subtropical highs

hot spot