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|
|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.