Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1175/JCLI-D-19-0110.1 |
Mechanisms Reducing ENSO Amplitude and Asymmetry via an Enhanced Seasonal Cycle in the Mid-Holocene | |
Iwakiri, Tomoki; Watanabe, Masahiro | |
2019-12-01 | |
发表期刊 | JOURNAL OF CLIMATE |
ISSN | 0894-8755 |
EISSN | 1520-0442 |
出版年 | 2019 |
卷号 | 32期号:23页码:8069-8085 |
文章类型 | Article |
语种 | 英语 |
国家 | Japan |
英文摘要 | Paleo proxy records have suggested that El Nino-Southern Oscillation (ENSO) variability during the mid-Holocene [8200 to 4200 years ago (8.2-4.2 ka)] was weaker than during the instrumental periods, but the mechanisms remain unclear. We examined processes of ENSO suppression using a coupled general circulation model (CGCM) that simulates ENSO amplitude and skewness under the present climate reasonably well. Two long simulations were performed: one using the preindustrial condition (CTRL) and the other using the 8-ka insolation having a greater seasonal cycle (MH8K). Consistent with proxy records and previous modeling studies, the ENSO amplitude weakened by 20% in MH8K compared to CTRL, mainly because of reduced thermocline feedback during the mature and decay phases. The weak thermocline feedback, likely a result of the loose equatorial thermocline in the mid-Holocene, suppresses the occurrence of extreme El Nino events and consequently explains the reduction in both ENSO amplitude and asymmetry. In MH8K, strengthened trade winds over the western-central Pacific Ocean act to cool the surface via evaporation while warmer water in the southern subtropical Pacific is transported beneath the equatorial thermocline, both contributing to diffuse the thermocline. Multimodel simulations for the mid-Holocene showed mean state changes and ENSO weakening similar to MH8K, but most models did not show reduced ENSO skewness, probably because of the failure in reproducing extreme El Nino events under the present climate. |
英文关键词 | Atmosphere Air-sea interaction Atmosphere-ocean interaction Climate variability El Nino ENSO |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000494720800003 |
WOS关键词 | SEA-SURFACE TEMPERATURE ; NINO-SOUTHERN OSCILLATION ; TROPICAL PACIFIC-OCEAN ; EL-NINO ; VARIABILITY ; CLIMATE ; HOLOCENE ; SUPPRESSION ; CMIP5 ; TRANSITION |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/225630 |
专题 | 环境与发展全球科技态势 |
作者单位 | Univ Tokyo, Atmosphere & Ocean Res Inst, Tokyo, Japan |
推荐引用方式 GB/T 7714 | Iwakiri, Tomoki,Watanabe, Masahiro. Mechanisms Reducing ENSO Amplitude and Asymmetry via an Enhanced Seasonal Cycle in the Mid-Holocene[J]. JOURNAL OF CLIMATE,2019,32(23):8069-8085. |
APA | Iwakiri, Tomoki,&Watanabe, Masahiro.(2019).Mechanisms Reducing ENSO Amplitude and Asymmetry via an Enhanced Seasonal Cycle in the Mid-Holocene.JOURNAL OF CLIMATE,32(23),8069-8085. |
MLA | Iwakiri, Tomoki,et al."Mechanisms Reducing ENSO Amplitude and Asymmetry via an Enhanced Seasonal Cycle in the Mid-Holocene".JOURNAL OF CLIMATE 32.23(2019):8069-8085. |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论