Interannual variability of oceanic heat fluxes in the Atlantic Sector of the Arctic Ocean

Lead Author Igor L., Bashmachnikov
Institution Contact 1 - Department of Oceanography at the Institute of Earth Science of the St. Petersburg State University (SPbSU), 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia; 2 - NIERSC- Nansen International Environmental and Remote Sensing Centre, 14th line, St. Petersburg, Russia;
Co-Authors Denis L. Volkov, University of Miami, USA; Alla Yu. Yurova, NIERSC- Nansen International Environmental and Remote Sensing Centre, Russia; Leonid P. Bobilev, NIERSC- Nansen International Environmental and Remote Sensing Centre, Russia;
Theme Theme 1: Vulnerability of Arctic Environments
Session Name 1.1 Climate Change and Environmental Management in the Arctic
Presentation Type Poster
Abstract text Oceanic heat fluxes (Q) from the Nordic seas into the Arctic are investigated using an eddy-permitting Massachusetts Institute of Technology primitive equation model, nested into an ECCO2 ocean state estimate, where semi-empirical model coefficients are optimized for the Arctic Ocean. The model has 50 vertical levels and in the Nordic seas its mesh size is around 4 km. It is forced with the Re-Analysis model of the Japan Meteorological Agency for the period 1992-2013.
The heat fluxes are estimated across 4 meridional sections in the Barents Sea Opening (BSO) and 4 zonal sections in the Fram Strait (FS). Comparison of the modelled means, in-depth and along-section variations of water temperature, volume fluxes and heat fluxes with the corresponding characteristics derived from in-situ measurements (Dickson et al., 2008) show a very close correspondence. The time-tendencies derived from the models and from in-situ data slightly differ, as the model predicts about 2 times less annual increase of Q in the BSO and the FS between 1997 and 2007. The model data were further verified using satellite derived surface horizontal fluxes.
Long-term variations of Q are investigated using wavelet analysis. The dominating periods are: seasonal, 2-4 year and 6-9 year periods. Intensity of the seasonal and interannual variations of Q have similar intensity in BSO and FS. The seasonal variations of Q in the BSO has slightly higher correlation with volume flux (V) them with integral inflow temperature (T), while those of the FS correlate with V and very weakly with T. The 2-4 year interannual variations of Q are significantly correlated with variations of V and T in BSO, and with V only in the FS. Relations of Q with local winds, sea-level variations and local ocean-atmosphere heat exchange are discussed.