Laptev Sea Shelf modelling
Rapid climate change affects the polar seas. The processes observed in the coastal and shelf regions are of particular interest, because ice retreat, permafrost thawing and an increase in temperature and volume of river runoff influence local ocean circulation and ecosystem dynamics. One of the areas of recent focus is the Lena Delta region of the Laptev Sea, which has been the subject of numerous observational studies over the recent years (Russian-German expeditions Lena-2007, Lena-2008, BARKALAV-2007/TRANSDRIFT-XII, POLYNIA- 2008/TRANSDRIFT-XIII, BARKALAV-2008/TRANSDRIFT-XIV). Interest in this area is partly motivated by the fact that the Lena River provides approximately 70% of the total runoff to the Laptev Sea.
The Lena River freshwater plume spreading is a key process defining the dynamics of the Laptev Sea region in the summer. It influences stability of the water column and modifies vertical mixing. Atmospheric winds and tidal mixing can be considered as main driving factors, and existing observational studies largely confirm this.
The Lena plume dynamics in the Lena Delta region of the Laptev Sea were explored by us in simulations performed with the Finite Volume Coastal Ocean Model (FVCOM) on a mesh with the horizontal resolution from 0.4–5 km. The impact of winds and tides on the Lena plume propagation were analysed based on simulations for the summer season of 2008 and also on idealized experiments.
The Lena River plume spreading, summer 2008
(Video by Vera Fofonova)
Fofonova, V. , Androsov, A. , Danilov, S. , Janout, M. , Sofina, E. and Wiltshire, K. H. (2014): Semidiurnal tides in the Laptev Sea Shelf zone in the summer season , Continental Shelf Research, 73 , pp. 119-132 . doi: 10.1016/j.csr.2013.11.010
Fofonova, V. , Danilov, S. , Androsov, A. , Janout, M. , Bauer, M. , Overduin, P. , Itkin, P. and Wiltshire, K. H. (2015): Impact of wind and tides on the Lena River freshwater plume dynamics in the summer season , Ocean Dynamics . doi: 10.1007/s10236-015-0847-5