Dynamics of simulated Atlantic upwelling annual cycle in CMIP5 models
As one of the prominent climatic component of tropical climate system, the annual cycle of the equatorial Atlantic cold tongue region has been a subject of significant research. In this work, we examine the fidelity of the key part of the annual cycles, namely, the upwelling annual cycles, from the simulations of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Utilizing the simple framework we have recently developed based on the Zebiak–Cane (ZC) ocean model, we first tested the validity of the simple framework of upwelling as a combination of the local wind–driven Ekman upwelling and nonlocal wind–driven wave upwelling. It is demonstrated that the theoretically reconstructed upwelling annual cycles to large extent are in good agreement with the simulations in these coupled climatic models. Comparing with observations, we show that the semiannual component of the upwelling is systematically too strong. This significant bias is attributable to the dynamic amplification to the wind–driven wave upwelling originated from a less significant bias in the semiannual harmonic component in the central equatorial wind field. The latter is dynamically amplified in the wind–driven wave upwelling owing to its relatively fast time scale. Furthermore, the realistic simulations of equatorial annual cycles may sensitively depend on good simulations of the semiannual harmonic components in equatorial wind fields.
- Research Organization:
- Univ. of Hawaii at Manoa, Honolulu, HI (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- SC0005110; 105-2119-M-003-003; 104-2611-M-003-002-MY3
- OSTI ID:
- 1474276
- Alternate ID(s):
- OSTI ID: 1377940
- Journal Information:
- Journal of Geophysical Research. Oceans, Vol. 122, Issue 7; ISSN 2169-9275
- Publisher:
- American Geophysical UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Dynamics of Upwelling Annual Cycle in the Equatorial Pacific Ocean
|
journal | September 2019 |
Inter-annual variability in the tropical Atlantic from the Last Glacial Maximum into future climate projections simulated by CMIP5/PMIP3
|
journal | January 2018 |
Interannual Variability in the Tropical Atlantic from the Last Glacial Maximum into Future Climate Projections simulated by CMIP5/PMIP3
|
posted_content | November 2017 |
Similar Records
Aperiodic variability in the Zebiak-Cane coupled ocean-atmosphere model: Air-sea interactions in the western equatorial Pacific
Simulation of the tropical Pacific climate with a coupled ocean-atmosphere general circulation model. Part I: The seasonal cycle