جستجوی مقالات مرتبط با کلیدواژه "اقیانوس هند شمالی" در نشریات گروه "فیزیک"

With identification of monthly surface currents in an ocean area, one can detect accumulation of pollutants, sea fronts and ocean eddies. Surface currents are derived from two components; Ekman component (current due to wind) and geostrophic current (current due to change in sea surface height). Since measurement of oceanic currents is difficult and time consuming, OSCAR satellite data is used in this paper to look at the current vectors in the Indian Ocean using Arcmap software. After plotting the vectors of these streams, the path of each current flow and its characteristics are noted and the average surface waters of the North Indian Ocean are surveyed in different sections of the study. The results show six sustained and significant flow patterns in the north of the Indian Ocean along with their ivy. The strongest current in the north of the Indian Ocean, the Somali stream, and the eastern Arabic flow are weaker than all the streams of this region. The average flow velocity is 0/12 m/s. Typical velocity varies from 0.001 m/s to 1.37 m/s is this ocean. Currents with measo-scale eddies have also a typical velocity of 0.7 m/s.

In the Northern Indian Ocean, monsoon reversing winds induce the variation in the characteristics of mixed layer depth (MLD). MLD as one of the most important quantities of the upper ocean plays a vital role in several physical, chemical, biological oceanographic and climatic phenomena. Using the most accurate bathymetry data with spatial resolution of 0.033deg and monthly temporal resolution using the MITgcm model and the use of a suitable criterion for the detection and diagnosis of MLD and BLT(Barrier Layer thickness) is one of the characteristics of this study. According to the results of this study, there is a significant change in MLD from summer monsoon to winter monsoon. In January/February, the southern coast of Iran and Pakistan toward its south, MLD varies from 125meters to 65meters. The highest values were found near the east coast of the North Indian Ocean, between 85 meters and 125 meters, and the lowest is about 85 meters near the western coast and near Oman. In July /August, from the southern coast of Iran and Pakistan toward its south, MLD varies from 15 meters to 45 meters. In general, during both the monsoons the MLDs on the eastern side of the ocean are deeper than the its western side. On the other hand, BLT has more presence in the area in the winter than summer. The causes of variations are can be found in factors such as precipitation, evaporation, wind stress, current inversions, pure surface heat during summer monsoon and winter monsoon.