オホーツク海の存在が弱める冬季北半球規模帯状平均流

• Main Author: Kawasaki, Kenta
• Other Authors: 立花, 義裕, 33218
• Format: Other/Unknown Material
• Language: English
• Published: 三重大学 2017
• Subjects: Arctic; Okhotsk; aleutian low; okhotsk sea; Sea ice; Siberia
• Online Access: https://mie-u.repo.nii.ac.jp/record/11568/files/2016M276.pdf

application/pdf It is commonly known that the development of Arctic Oscillation (AO) is one of the most famous climatic phenomenon in winter season. Some studies pointed out that the atmospheric response of the changed troposphere and stratosphere by thermal response caused by the fluctuation of Arctic sea-ice affects extremely to winter AO. However, little has been known that whether or not the marginal sea in mid-latitude affects to the atmospheric circulation in winter season. The Okhotsk Sea, which is located to the north of Japan, has characteristic that be warmer extremely than surrounding continental in winter season. The variability of sea-ice areas in the Okhotsk Sea was shown that impacted to the strength of Aleutian low in winter by propagated of the stationary Rossby wave caused by the different of thermal response. Therefore, the Okhotsk Sea has the potential that impact to the large-scale atmospheric circulation and it is also important climatologically that understand its mechanism. This study focused on the role of existence of the Okhotsk Sea for the large-scale atmospheric circulation in winter by using Atmospheric General Circulation Models (AGCM). One GCM is executed without the Okhotsk Sea, in which was changed to continent as if the Okhotsk Sea was totally landfilled (LAND). The other (CTL) is a under the boundary condition of climatic seasonal changes of the Sea Surface Temperature (SST)over the globe. The comparison of the CTL with the LAND showed that the cold air (hot air) is strengthened in the Europe (eastern Siberia) in December by the strengthened advections in the each areas by the dominated wave train caused by the existence of the Okhotsk Sea. Eliassen-Palm flux (EP-flux)shown the propagation of planetary wave is propagated upward and converged in stratosphere by forced the poleward eddy heat transport caused by strengthened the temperature and meridional wind associated with wave train. Troposphere and stratosphere were coupled from December to January because stratosphere at ...