فهرست نشریات علمی دسترسی آزاد ایران

Getting to know the oceans Mean Dynamic Topography (MDT) derived from the satellite altimetry data helps to study climates and steady state currents in the oceans. A MDT model named as MDT_IAU_TN_2014, including steady state surface currents was developed by the Islamic Azad University of IRAN, Tehran-North branch, hydrography group. The model includes magnitudes and directions of currents in the region of Persian Gulf and Indian Ocean given in a grid with 2’x2’ arc minutes spacing in the latitude and longitude directions. To build up the model, a Mean Sea Surface (MSS) model should be subtracted from a Geoid heights model. An MSS called MSS_IAU_TN_2014, is derive using observations of 21 years of 6 altimetry satellites: Topex-Poseidon (T/P); ERS (E1) and (E2); Jason (J1) and (J2); Geosat Follow-On (GFO). MSS_IAU_TN_2014 differences relative to the MSS_CNES_CLS_2011 has 0.1 m RMS. Also a series of global geopotential coefficients estimated from four years of GOCE data is used to compute the geoid. A truncated Gaussian Filter with truncation radius of 1.386 arc degrees was used to match the spectral content of both MSS and Geoid. Sea Level Anomaly (SLA) an In-Situ data could be used to make the MDT_IAU_TN_2014 independent from any other models. At last, MDT_IAU_TN_2014 was compared with MDT_CNES_CLS09 0.51m RMS and MDT_DTU_2010 with 0.033m RMS. Velocity vectors from MDT_IAU_TN_2014 shows near coast currents perfectly, but there is some weakness in Oman Sea gyres details.