Kyushu University Academic Staff Educational and Research Activities Database
List of Reports
Last modified date:2021.06.08

Post-doctoral Fellow / Division of Earth Environment Dynamics / Research Institute for Applied Mechanics


Reports
1. Influence of El Nino on Winter Climate of Japan
Influence of the ENSO (El Niño/Southern Oscillation) on East Asian winter monsoon is examined. It is widely accepted that the El Niño tends to bring warm climate in December-January-February (DJF) winter season in Japan. However, our study reveal that in the DJF-averaged fields the ENSO has little impact on the near-surface temperature anomalies there. In particular, near-surface temperature anomaly fields in the late winter show neutral signals. Simultaneously, the Pacific-Northern American (PNA) pattern is dominant in the upper troposphere while no strong signals are found near Japan. In contrast, in the early winter, the WP pattern with positive phase are dominant so that winter tends to be warm in Western Japan. The opposite is true for La Niña. Dynamical mechanisms of such seasonal evolutions in the upper-level height field from early winter to late winter are not yet clarified yet and thus remain for future work..
2. Tropical Sea Surface Temperature Anomaly and the Winter Climate of Japan during ENSO.
3. The Relationship between Upper-level Atmospheric Responses and Japanese Winter Climate during El Nino
In the Far East, El Niño (La Niña) typically brings warm (cold) winter via the teleconnections excited by the anomalous sea surface temperature (SST) in the tropics. Some ENSO events, however, have the opposite tendencies. To understand the mechanisms of the disparate mid-latitude responses during ENSO, composite analysis has been conducted using long-term reanalysis dataset. Our analysis shows that about 63% (67%) of all El Niño (La Niña) events are classified as typical warm (cold) winter around Japan and about 37% (33%) as atypical events. A Western Pacific (WP)-like pattern appears in typical events. Surprisingly, the Pacific/North American (PNA) pattern, which is a well-known feature during ENSO, is obscure during typical events. In fact, the PNA pattern dominates during atypical events with large amplitudes. In addition, SST distributions differ not only in the eastern Pacific Ocean but also in the western Pacific Ocean. These SST anomalies seem to cause differences divergence wind anomalies to cause different atmospheric responses in the mid-latitudes during ENSO..
4. The Mid-latitude Responses Categorized by the Winter Climate in the Far East during El Nino.
5. WP/PNAインデックスと熱帯海面水温偏差との関係.
6. 極東域におけるEl Ninoの冬季気候への影響.
7. Influence of El Nino on Winter Climate of Japan.
8. Tropical Sea Surface Temperature Anomaly and the Winter Climate of Japan during ENSO.
9. ENSOと極東域の寒暖との関係.
10. The Relationship between Upper‐level Atmospheric Responses and Japanese Winter Climate during El Nino.
11. NINO.3インデックスと日本付近における冬の寒暖との関係.
12. El Nino時における冬季極東域への異なる影響に対応する熱帯太平洋・インド洋SST偏差パターン.
13. The Mid‐latitude Responses Categorized by the Winter Climate in the Far East during El Nino.