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...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of geophysical research. Oceans Jg. 122; H. 7; S. 5774 - 5785
Hauptverfasser: Wang, Li‐Chiao, Jin, Fei‐Fei, Wu, Chau‐Ron
Format: Journal Article
Sprache:Englisch
Veröffentlicht: Washington Blackwell Publishing Ltd 01.07.2017
American Geophysical Union
Schlagworte:
Amplification
Annual
Annual cycles
Annual variations
Atlantic
Atmospheric circulation
Bias
Climate
Climate models
Climate system
CMIP5
Cold regions
Components
Computer simulation
Cycles
Dynamics
ENVIRONMENTAL SCIENCES
Equatorial regions
Equatorial upwelling
Fields
Frameworks
Geophysics
Intercomparison
Local winds
Meteorology
Ocean circulation
Ocean models
Ocean-atmosphere interaction
Oceans
Simulation
Tropical climate
Tropical climates
tropics
Upwelling
wind
Wind fields
ISSN:2169-9275, 2169-9291
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung: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. Thus, the realistic simulations of equatorial annual cycles may sensitively depend on good simulations of the semiannual harmonic components in equatorial wind fields. Key Points The simple theory based on the framework of Zebiak‐Cane ocean model for upwelling annual cycle also works well in CMIP5 simulations The semiannual component of the upwelling annual cycles in CMIP5 is systematically too strong owing to the dynamic amplification The realistic simulations of equatorial upwelling annual cycles may sensitively depend on good simulations of central equatorial wind fields
Bibliographie:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
content type line 23
SC0005110; 105-2119-M-003-003; 104-2611-M-003-002-MY3
USDOE Office of Science (SC)
ISSN:2169-9275
2169-9291
DOI:10.1002/2017JC012781