Vertical structure of the mesoscale eddies in the Gulf of Mexico
Vertical structure of the mesoscale eddies in the Gulf of Mexico
Abstract:
The vertical structure of the anticyclonic and cyclonic eddies ubiquitous in the Gulf of Mexico is obtained using a combination of
altimetry imagery and observations of 32 moorings of the CANEK group during the period of 2007-2012. Eddy composites are
constructed in two regions: The Loop Current system (eddy generation region) and the western Gulf of Mexico (eddy dissipation region).
We found differentthermohaline and cinematic vertical structures in the eddies of both regions of study. The temperature (T'), salinity (S'),
and speed ($|{\bf u}'_h|$) anomalies in the core of anticyclonic eddies of the eastern Gulf are located at $z\simeq-180\,{\rm m}$,
$z\simeq-250\,{\rm m}$, and $z\simeq-70\,{\rm m}$ respectively, whose maximum values are of $+2.9^\circ{\rm C}$, $+0.3\,{\rm ppm}$,
and $|{\bf u}'_h|\simeq0.52\,{\rm m}\,{\rm s}^{-1}$, respectively. In contrast, the anticyclonic eddies in the western Gulf of Mexico have maximum
anomalies of $+2.4^\circ{\rm C}$, $+0.24\,{\rm ppm}$, and $\in[0.14-0.24]\,{\rm m}\,{\rm s}^{-1}$ located at $z\simeq-180\,{\rm m}$,
$z\simeq-350\,{\rm m}$, and $z\simeq-70\,{\rm m}$, respectively. These differences are explained by the fact that the waters of Caribbean
origin are transformed into common Gulf waters during the propagation of these eddies to the western Gulf of Mexico; and the decrease of
speed is attributed to eddy-eddy and/or eddy-shelf interactions. Thethermohaline and cinematic composites of the cyclonic eddies in both
regions of study are also contrasting. The cyclones in the region of the Loop Current have intense anomalies of $-7.5^\circ{\rm C}$ (T'),
$-0.95\,{\rm ppm}$ (S') and $|{\bf u}'_h|\simeq0.52\,{\rm m}\,{\rm s}^{-1}$ ($|{\bf u}'_h|$) located at $z\simeq-180\,{\rm m}$,
$z\simeq-300\,{\rm m}$, and $z\simeq-70\,{\rm m}$, respectively. These anomalies are $\sim3$ times smaller in the cyclones ubiquitous
in the western region. These differences are related with the different mechanisms of cyclonic eddy generation of each region, and the water
masses that these eddies trap during its genesis. In general we observe thatmesoscale eddies in the Loop Current are larger, with larger
vertical extension, saltier, colder, and with higher speeds than the eddies of the western Gulf.
constructed in two regions: The Loop Current system (eddy generation region) and the western Gulf of Mexico (eddy dissipation region).
We found different
and speed ($|{\bf u}'_h|$) anomalies in the core of anticyclonic eddies of the eastern Gulf are located at $z\simeq-180\,{\rm m}$,
$z\simeq-250\,{\rm m}$, and $z\simeq-70\,{\rm m}$ respectively, whose maximum values are of $+2.9^\circ{\rm C}$, $+0.3\,{\rm ppm}$,
and $|{\bf u}'_h|\simeq0.52\,{\rm m}\,{\rm s}^{-1}$, respectively. In contrast, the anticyclonic eddies in the western Gulf of Mexico have maximum
anomalies of $+2.4^\circ{\rm C}$, $+0.24\,{\rm ppm}$, and $\in[0.14-0.24]\,{\rm m}\,{\rm s}^{-1}$ located at $z\simeq-180\,{\rm m}$,
$z\simeq-350\,{\rm m}$, and $z\simeq-70\,{\rm m}$, respectively. These differences are explained by the fact that the waters of Caribbean
origin are transformed into common Gulf waters during the propagation of these eddies to the western Gulf of Mexico; and the decrease of
speed is attributed to eddy-eddy and/or eddy-shelf interactions. The
regions of study are also contrasting. The cyclones in the region of the Loop Current have intense anomalies of $-7.5^\circ{\rm C}$ (T'),
$-0.95\,{\rm ppm}$ (S') and $|{\bf u}'_h|\simeq0.52\,{\rm m}\,{\rm s}^{-1}$ ($|{\bf u}'_h|$) located at $z\simeq-180\,{\rm m}$,
$z\simeq-300\,{\rm m}$, and $z\simeq-70\,{\rm m}$, respectively. These anomalies are $\sim3$ times smaller in the cyclones ubiquitous
in the western region. These differences are related with the different mechanisms of cyclonic eddy generation of each region, and the water
masses that these eddies trap during its genesis. In general we observe that
vertical extension, saltier, colder, and with higher speeds than the eddies of the western Gulf.