A research group of 31 institutions led by the National Institute of Polar Research and the Atmosphere and Ocean Research Institute of the University of Tokyo analyzed the temperature and dust for the past 72 years using ice cores excavated at Dome Fuji, Antarctica.It was clarified that climate instability (variability) increases during the period when the temperature is in the middle of the glacial period, and that the main cause is global cooling due to the decrease in the greenhouse effect.
Climate change susceptibility (climate instability) has a great impact on the earth's natural environment and human society.Therefore, it is important to know when instability has increased in the past, clarify the cause, and reproduce it in a climate model, as well as whether global warming will increase instability in the future. ..Looking at the past, studies of numerous ice cores in Antarctica and Greenland have shown that during the last glacial period (about 10 to 2 years ago), there were more than 25 thousands of years of temperature fluctuations in Antarctica. It is known that they were related to the rapid warming and cooling of the northern hemisphere.
However, due to the lack of data and the low time resolution of ice cores older than the Last Glacial Period, the relationship between climate instability and mean conditions and the causes of instability have not been well understood. ..
This study reveals for the first time long-term trends and mechanisms, including multiple glacial periods.There is no guarantee that the interglacial period (warm period), which has continued for more than 1 years, will be stable in the future, suggesting that the melting of the existing Greenland ice sheet may lead to climate instability. ..
The Dome Fuji ice core used in this study was excavated from 2001 to 07 according to the "Second Dome Fuji Observation Plan" carried out in the Antarctic Research Expedition from 2 to 2003.In addition, the "Earth Simulator" of the Japan Agency for Marine-Earth Science and Technology was used for numerical experiments using climate models.
