Anomalous transport of heat and salt by a long-lived anticyclonic eddy  in the northeast tropical Pacific Ocean

2021 ◽  
Author(s):  
Kaveh Purkiani ◽  
Maren Walter ◽  
Matthias Haeckel ◽  
Katja Schmidt ◽  
André Paul ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Dissolved Oxygen ◽  
Mesoscale Eddy ◽  
Tropical Pacific ◽  
Anticyclonic Eddy ◽  
Altimeter Data ◽  
Positive Temperature ◽  
Tropical Pacific Ocean ◽  
High Rotational Speed ◽  
The Impact

<p><span>During RV Sonne expedition SO268 to the northeast tropical Pacific Ocean between March and May 2019, the impact of a mesoscale eddy on the seawater properties was investigated by conducting a multiple of observations. A subsequent analysis of an altimeter data revealed the formation of an anticyclonic mesoscale eddy in the Tehuantepec gulf between 15 and 20 June 2018 with a mean radius of 185 km and an average speed of 13 cm/s. This extremely long-lived eddy carried sea-water characteristics from near coastal Mexican waters westward far into the open ocean. The water mass stayed largely isolated during the 11 months of travel time due to high rotational speed.</span></p><p><span>The eddy exhibited a conical-shape vertical structure with concurrent deepening of the main thermocline. The water in the eddy core showed an extreme positive temperature anomaly of 8</span><sup><span>◦</span></sup><span>C, a negative salinity anomaly of -0.5 psu and a positive dissolved oxygen concentration anomaly of +160 μmol/kg centered at 80 m depth. The sub-surface impact of the eddy is clearly evident in the temperature and salinity profiles at a depth of 1500 m. For dissolved oxygen the eddy-induced anomaly reached even deeper to the seafloor.</span></p><p><span>This study provides new insights to the offshore transport of heat and salt driven by the long-lived anticyclonic eddy in the northeast tropical Pacific Ocean. Considering the water column trapped within the eddy, a positive heat transport anomaly of 1-3 ×10</span><sup><span>11</span></sup><span> W and a negative salt transport anomaly of -8×10</span><sup><span>3</span></sup><span> kg/s were estimated. However, due to the rare occurrence of long-lived anticyclone eddies in this region, they likely do not play a significant role in affecting the heat and salt balance of the northeastern tropical Pacific Ocean. </span></p>

The impact of global warming on the tropical Pacific Ocean and El Niño

2010 ◽  
Vol 3 (6) ◽  
pp. 391-397 ◽  
Author(s):  
Mat Collins ◽  
Soon-Il An ◽  
Wenju Cai ◽  
Alexandre Ganachaud ◽  
Eric Guilyardi ◽  
...  
Keyword(s):  
Global Warming ◽  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Tropical Pacific ◽  
Tropical Pacific Ocean ◽  
The Impact ◽  
The Tropical Pacific

The unexpected salinity trend shifts in upper Tropical Pacific Ocean under the global hydrological cycle framework

2021 ◽  
Author(s):  
Huangyuan Shi ◽  
Ling Du
Keyword(s):  
Global Warming ◽  
Pacific Ocean ◽  
Water Cycle ◽  
Tropical Pacific ◽  
Secular Change ◽  
Upper Ocean ◽  
Tropical Pacific Ocean ◽  
Surface Salinity ◽  
Ocean Salinity ◽  
The Impact

<p>The secular change of ocean salinity is regarded as an indicator of the global water cycle by measuring the surface freshwater flux which is the most important component of earth hydrological budget. Under the effect of remarkable global warming, the surface salinity patterns in ocean basins illustrated that the intensified water cycle resulted in the continuous and significant freshening phenomena in tropical ocean. With the recent boom in salinity measurements and observations, the variability of surface salinity was examined to explore its relationship with anthropogenic warming. In this paper, we found that the salinity varied on the decadal to centurial time scales and responded significantly to the global warming in tropical Pacific Ocean by using the multi-source reanalysis datasets. An unexpected distribution was figured out and what is noteworthy is that, the robust salinification occurred in the central tropic Pacific in the first two decades of 21<sup>st</sup> which was demonstrated by Argo observations. Nevertheless, it did not follow the typical salinity patterns that ‘wet get wetter’ mentioned by several literatures and illustrated a significant trend shift. Similarly, the subsurface ocean salinity revealed the same shift but an opposite tendency to that on surface. It may involve that the controlling influence of surface freshwater reduced and the impact of ocean thermodynamic adjustment became gradually pronounced to the upper ocean. The salinity budget suggested that salinity advection and subsurface entrainment played key roles to induce the reversed trend of salinity change. In addition, the isopycnals variability caused by wind-driven ocean pumping and subtropical gyre may be acted as a trigger of the salinity enhancement in the upper ocean. What’s more, the impact of PDO decadal shift and the moderate global warming was seemed to be the essential factors to change the feedback of ocean-atmosphere processes, potentially and was finally reflected on ocean salinity field.</p>

scholarly journals The Impact of Satellite Winds and Latent Heat Fluxes in a Numerical Simulation of the Tropical Pacific Ocean

2006 ◽  
Vol 19 (22) ◽  
pp. 5889-5902 ◽  
Author(s):  
Ludos-Herve Ayina ◽  
Abderrahim Bentamy ◽  
Alberto M. Mestas-Nuñez ◽  
Gurvan Madec
Keyword(s):  
Pacific Ocean ◽  
Latent Heat ◽  
Weather Prediction ◽  
Turbulent Fluxes ◽  
Tropical Pacific ◽  
Heat Fluxes ◽  
Tropical Pacific Ocean ◽  
Equatorial Pacific Ocean ◽  
The Impact ◽  
The Tropical Pacific

Abstract Several oceanic operational programs use remotely sensed fluxes to complement atmospheric operational analyses from major national weather prediction centers. The main goal of this study is to evaluate the ability of the ocean model (ORCA) to correctly simulate the dynamic of the tropical Pacific Ocean in 1996–98 when forced by the satellite turbulent fluxes (wind stress and latent heat fluxes). The results are compared with the oceanic response resulting from forcing the model with the European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis. Three sensitivity simulations forced with satellite and atmospheric analysis fields are performed. The control experiment is forced with the ECMWF fluxes. The solutions of these simulations are compared with data from the Tropical Atmosphere–Ocean (TAO) buoys and from sea surface temperatures analysis by Reynolds and Smith in the equatorial Pacific Ocean. The analysis results indicate that the model reproduces well the major spatial and temporal oceanic structures including the main characteristics of the 1997–98 El Niño. More specifically, the comparisons with buoys indicate that the experiment forced by the winds and the satellite latent heat fluxes is closer to the observations. They provide weak rms difference and strong correlations along the whole 500-m depth column. Furthermore, the correlations with the SST analysis vary between 75% and 95% compared to 65% and 77% for the experiment forced by ECMWF fluxes. The currents in the first 350 m also show a strong sensitivity to satellite turbulent fluxes.

scholarly journals Multidecadal Sea Level and Gyre Circulation Variability in the Northwestern Tropical Pacific Ocean

2012 ◽  
Vol 42 (1) ◽  
pp. 193-206 ◽  
Author(s):  
Bo Qiu ◽  
Shuiming Chen
Keyword(s):  
Pacific Ocean ◽  
Sea Level Rise ◽  
Sea Level ◽  
Model Simulation ◽  
Surface Wind ◽  
Tropical Pacific ◽  
North Equatorial Current ◽  
Altimeter Data ◽  
Upper Ocean ◽  
Tropical Pacific Ocean

Abstract Sea level rise with the trend >10 mm yr−1 has been observed in the tropical western Pacific Ocean over the 1993–2009 period. This rate is 3 times faster than the global-mean value of the sea level rise. Analyses of the satellite altimeter data and repeat hydrographic data along 137°E reveal that this regionally enhanced sea level rise is thermosteric in nature and vertically confined to a patch in the upper ocean above the 12°C isotherm. Dynamically, this regional sea level trend is accompanied by southward migration and strengthening of the North Equatorial Current (NEC) and North Equatorial Countercurrent (NECC). Using a 1½-layer reduced-gravity model forced by the ECMWF reanalysis wind stress data, the authors find that both the observed sea level rise and the NEC/NECC’s southward migrating and strengthening trends are largely attributable to the upper-ocean water mass redistribution caused by the surface wind stresses of the recently strengthened atmospheric Walker circulation. Based on the long-term model simulation, it is further found that the observed southward migrating and strengthening trends of the NEC and NECC began in the early 1990s. In the two decades prior to 1993, the NEC and NECC had weakened and migrated northward in response to a decrease in the trade winds across the tropical Pacific Ocean.

Sign in / Sign up

Export Citation Format

Share Document