Unit:
Κατεύθυνση Φυσική ΩκεανογραφίαLibrary of the School of Science
Author:
Anastasopoulou Gerasimi
Supervisors info:
Σαράντης Σοφιανός, Επίκουρος Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Έλενα Φλόκα, Καθηγήτρια, Τμήμα Φυσικής, ΕΚΠΑ
Μαρία Χατζάκη, Επίκουρη Καθηγήτρια, Τμήμα Γεωλογίας και Γεωπεριβάλλοντος, ΕΚΠΑ
Original Title:
Η επίδραση της θολερότητας στην ισημερινή κυκλοφορία του Ειρηνικού με τη χρήση δεδομένων αριθμητικού μοντέλου
Translated title:
The effect of turbidity on the equatorial circulation of the Pacific Ocean using numerical simulations
Summary:
Turbidity has a direct effect on the Sea Surface Temperature (SST) of the ocean, through the absorption of solar radiation in the upper layers. In the present thesis, in order to study the effect of turbidity on the dynamic characteristics and the circulation of the ocean, the meridional and vertical distribution of the Pacific Ocean are examined, focusing on the dynamics of the circulation cells of the Pacific Equator. The study was carried out by performing an analysis of the results of the numerical model NEMO, using the results of experiments with different turbidity parameterization. In particular, the increase in turbidity was achieved by reducing the attenuation depth of radiation. Two quite opposite experiments were conducted, the Type I experiment with zero turbidity (clean waters) and the Type III experiment with high turbidity (turbid waters). From that difference between the experiments, it was found that increase of stratification in the surface layer, results in the reduction of turbulence, which is expressed by the eddy viscosity coefficient Av. The reduction of Av by 33 results in the reduction of the wind-forced (Ekman) layer by 29%, the reduction of vertical velocity and the development of stronger surface horizontal flow. This mechanism drives a significantly stronger surface divergence in the Equatorial region, by 56%, leading to the increase of upwelling, which transfers a larger amount of cooler subsurface waters, thereby cooling the surface of the Pacific Equator.
Main subject category:
Science
Keywords:
turbidity, Pacific Ocean, numerical simulation, NEMO, attenuation depth, eddy viscosity coefficient
