Water exchange in the straights of northern Ladoga: Results of field studies and numerical simulations

Abstract

Water exchange was studied in the northern skerries part of Lake Ladoga in summer 1994 using an ADCP current profiler. Twelve transects were made in the main straights and bays. The highest recorded discharge was equal to 316 m 3s −1. Measurements were compared with circulation patterns, calculated using a two-dimensional depth-averaged finite element model. A numberical particle tracking method was used to obtain the maximum number of trajectories of dissolved contaminants from the main pollution sources on the lake shore: the paper-pulp mills at Läskelä and Pitkäranta and municipal sewage waters release of Sortavala.