Application of inverse technique to study radioactive pollution and mixing processes in the Arctic Seas

Abstract

Rare noisy observations of the dissolved and suspended Cs 137, and the dissolved Sr 90 collected for years 1985 and 1994, respectively, are utilized through an inverse method to estimate the radionuclide pollution and the mixing time scale, namely the age, of the White and Kara Seas. We demonstrate how uncertainties, such as measurement noise, inhomogeneous station disposition and others depress the identification utility of the radioactive observations in the Arctic Seas to validate regional radioecological models. The special approach estimates the current and mean radionuclide pollution from the rare observations. We found the mean integral amount of cesium (strontium) pollution of the White Sea (in 1985) and Kara Sea (in 1992) did not exceed ∼70 (41) TBq and ∼16 (9) TBq, respectively, and radioactive background of these seas is low in comparing to the Black and Barents Seas. Estimations of the age confirm the fact of the rapid ventilation of the Kara Sea, but not the White Sea. The age ranges from 1–2 years for the Kara Sea till 5–6 years for the White Sea. That factually says about the possibility of the long-term accumulation of radionuclides in the White Sea.