Assessment of SARAL-ALTIKa alongtrack sea level observations (Tidal correction) over Indian Coastal Ocean M. Salim ,R. K. Nayak, V K Dadhwal [email protected],[email protected] Earth and Climate Sciences Area (ECSA) National Remote Sensing Centre (ISRO), Hyderabad International SARAL Science and Application meet 22-24 Apr 2014 Space Application Centre (SAC), Ahmedabad, India Introduction • One of the major challenge in the Altimetric observations in the coastal area is the accurate tidal correction • India has a very long coastline - aprox- 7500km ; it consists of High, moderate and low tidal regions • The global tidal models may not be correct • Here – we have made an attempt to asses the global tidal models along Indian costal region Tidal correction…. How accurate is This? T023 C2 Cycle Apr 2013 Tracks of SARAL-ALTIKa T468 Sea level (cm) T468 C1 Cycle March 2013 Sea level (cm) T023 1. FES Tidal corrections in ALTIKA sea level for the shallow coastal regions may not be appropriate. T468 C2 Cycle Apr 2013 2. Regional Model to be formulated. 3. We have made it  based on POM-OGCM ALTIKA SSA+Tide FES Tide ALTIka SSA DEPTH Land side Ocean Side Land side Ocean Side OSG-ECSA-NRSC Formulation of Regional Tidal Model for Indian Coast 1. 2. 3. Initial Model State Surface boundary conditions Lateral Boundary conditions The Princeton Ocean Model – a 3D OGCM 1. 2. 3. 4. 5. Conservation of Mass Conservation of Momentum Conservation of Energy Equation of State Mixedlayer –turbulent closure scheme Partial differential Equations  Solved in Finite difference Numerical Methods in a SIGMA-Curvilinear CoOrdinate System External barotropic mode and Internal baroclinic mode Simulated Sea Level 350 cm Gulf of Khambhat Amplitude and Phases of Major Tides 0 cm 200 cm M2 Phase -350 cm S2 Amplitude M2 Amplitude Hooghly Harmonic Analysis Simulated Sea level, Currents T &S profiles 0 cm 80 cm S2 Phase 360deg 0deg ERRORS (RMSE) at Tide Gauge Stations vvv 1. FES tides have more error at the NW and NE coastal stations with wider and converging continental shelves Hooghly Gulf of Khambhat v 2. They are very accurate at most of tide gauge stations. INCOIS has provided Tide Gauge DATA Tide gauge stations from NW (OKHA) to NE (HALDIA) coast of Indian Thank You