Variability of low-level coastal jet (LLCJ) on modulation of the sea-surface temperature in the Southeast Pacific
Abstract
The SST changes corresponding to the variability of the LLCJ with respect to the strong and weak jet periods during the VAMOS Ocean-Cloud-Atmosphere-Land Study (VOCALS) field campaign from 20 October to 30 November 2008 are studied. A fully coupled two-way air-ocean model simulation using the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) is performed to obtain the atmospheric and oceanic fields. The model results for the variability of LLCJ are compared with the satellite observation of wind, liquid water path (LWP) and sea surface temperature (SST). Three major processes including Ekman transport, Ekman pumping and air-sea net heat flux exchange associated with the coastal jet variability are investigated. The results indicate that the net heat flux exchange including the short and long wave radiations, latent heat and sensible heat flux is the most prominent process in modulating the SST change during both the strong and weak jet periods. The maximum SST cooling by the net heat flux is 31% more than by the Ekman transport and 78% more than by the Ekman pumping during the strong jet period. The net heat flux induced cooling covers most area of the domain, while the cooling by the Ekman transport covers offshore distance up to 500-1000 km and by the Ekman pumping is most concentrated within 100 km off the coast. The SST warming during the weak jet period is also mainly by the net heat flux exchange with a contribution of 71% for the maximum warming. The higher resolution of the two-way coupled air-ocean model simulation provides more detailed insight and smaller features for the relative role of the three processes in modulating the SST change.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMOS43A1528H
- Keywords:
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- 3307 ATMOSPHERIC PROCESSES / Boundary layer processes;
- 4217 OCEANOGRAPHY: GENERAL / Coastal processes;
- 4279 OCEANOGRAPHY: GENERAL / Upwelling and convergences