The simulations of circulation in the Laptev Sea using FVCOM
The Lena delta region of Laptev Sea can serve as an indicator of climate changing. A large number of observed data in this region suggests a strong climate change and biological data for the last thirty years. Unfortunately we still have not fully answer about extent of the changes and their causes in this region. One of the goals of my modeling is simulation of ecosystem dynamics in the Lena Delta region of the Laptev Sea. The dynamics are sensitive to the temperature and salinity variability and thus are connected to the ocean circulation dynamics. We explore them with the help of the Finite Volume Coastal Ocean Model. Local patterns of temperature and salinity in the mixed layer (up to 50 meters) in the Lena Delta Region of the Laptev Sea are analyzed for different regimes of atmospheric circulation (anticyclonic and cyclonic) with time scales of 5 – 30 days. We also assess the influence of Lena runoff temperature, local wind pattern and tidal dynamics on the temperature and salinity variability in the area. A particular attention is paid to the impact of local bathymetry data to temperature and salinity local pattern. May of 2008 and 2009 were chosen as test periods. Simulations were carried out with the Finite Volume Coastal Ocean Model (FVCOM). FVCOM is a prognostic, unstructured-grid, finite-volume, free-surface, 3-D primitive equation coastal ocean circulation model. It was used by us in a variant including wetting and drying, GOTM (turbulence model) and nudging of temperature and salinity at open boundaries. We used a high quality unstructured mesh, which allowed us to take into account the complex structure of coastline and bathymetry and other aspects of the problem (the necessity to refine mesh elements along main ways of Lena fresh water plumb). Element sizes vary from 400m to 3 km. The mesh has 6 vertical sigma layers with 250000 nodes on each of them. The input data (bathymetry, coastline, atmospheric forcing, initial temperature and salinity, climatological values for nudging at the open boundary, and runoff) are taken from NOAA, GEBKO and several other institutions.
AWI Organizations > Biosciences > Coastal Ecology
AWI Organizations > Climate Sciences > Climate Dynamics
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 4: Synthesis: The Earth System from a Polar Perspective > WP 4.3: Assessment of Coastal Climate Change in the Lena Delta Region of the Laptev Sea and in the North Sea