Pacific thermocline bridge revisited

نویسندگان

  • J. Miller
  • David W. Pierce
  • Tim P. Barnett
چکیده

The coupling on decadal time scales of the midlatitude and tropical Pacific via an oceanic 'bridge' in the thermocline is investigated using ocean general circulation model hindcasts and a coupled ocean atmosphere model. Results indicate that in the tropics decadal anomalies of isopycnal depth are forced by Ekman pumping and are largely independent of the arrival of subducted anomalies in the thermocline that originate in the mid-latitudes of either hemisphere. In the coupled model, temperature anomalies on isopycnals show little coupling from the tropics to the northern hemisphere, but are lag correlated between southern hemisphere midand low-latitudes. However, anomaly magnitudes on the equator are small. These results suggest that the oceanic 'bridge' to the northern hemisphere explains only a small part of the observed decadal variance in the equatorial Pacific. Coupling to the southern mid-latitudes via temperature anomalies on isopycnals remains an intriguing possibility.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Extratropical Air-Sea Interaction, Sea Surface Temperature Variability, and the Pacific Decadal Oscillation

We examine processes that influence North Pacific sea surface temperature (SST) anomalies including surface heat fluxes, upper ocean mixing, thermocline variability, ocean currents, and tropical-extratropical interactions via the atmosphere and ocean. The ocean integrates rapidly varying atmospheric heat flux and wind forcing, and thus a stochastic model of the climate system, where white noise...

متن کامل

Lecture 2 ENSO toy models

Let us consider first a heuristic derivation of an equation for the sea surface temperature in the East Pacific, which will be followed by a more rigorous derivation in the following sections. Assume that the East Pacific SST affects the atmospheric heating and thus the central Pacific wind speed. The resulting wind stress, in turn, excites equatorial Kelvin and Rossby ocean waves. These waves ...

متن کامل

Interpretation of tropical thermocline cooling in the Indian and Pacific oceans during recent decades

[1] A warming trend has been detected in the world’s oceans in recent decades. The basin-averaged warming, however, shows a complex vertical structure in the Indian and Pacific oceans. Warming in the upper ocean-with maxima near the surfaceaccompanies a strong cooling in the upper thermocline. Analysis of observed data and model solutions from this study reveals that the complex structure is co...

متن کامل

Low-Frequency Variability of Temperature in the Vicinity of the Equatorial Pacific Thermocline in SODA: Role of Equatorial Wave Dynamics and ENSO Asymmetry

The Simple Ocean Data Assimilation (SODA) reanalysis (1958–2001) is used to investigate the decadal variability in the equatorial thermocline in the Pacific.Whereas the thermocline depth exhibits weak variation at decadal time scales, the temperature change in the vicinity of the thermocline in the western Pacific is significant and has a vertical scale of;150 m. Based on a modal decomposition ...

متن کامل

Hemispheric Asymmetry in the Ventilated Thermocline of the Tropical Pacific

To understand sources of variability in the eastern equatorial Pacific, a region integral to modulating global temperatures, the waters upwelling from the Equatorial Undercurrent (EUC) are characterized. Past work is updated using temperature and salinity measurements from the Argo array and current measurements from Tropical Atmosphere Ocean (TAO) buoys. A larger hemispheric asymmetry is found...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1999