Bottom Morphostructure of the Valaam Archipelago in Lake Ladoga: First Video Images and Quantitative Assessments

Doklady Earth Sciences - Based on the first created digital model of the Valaam archipelago (Lake Ladoga) with a spatial resolution of 25 × 25 m, a quantitative assessment of the spatial...     

Morphometric Features of the Submarine Slope of the Southwestern Part of Valaam Island

Doklady Earth Sciences - A digital bathymetric model with a 10 × 10 m spatial resolution was created on the basis of the depth sounding on the southwestern slope of Valaam Island with the use...     

Determining the Velocity of the Upper Layer of Lake Ladoga by Means of Maximum Cross Correlation (MCC)

Izvestiya, Atmospheric and Oceanic Physics - The first use of Maximum Cross Correlation to calculate the surface currents of Lake Ladoga yields very promising results in the absence of direct...     

Variability of the horizontal gradients of the air and the water surface temperatures in the vernal frontal zone period of Lake Ladoga

Every year, the during springtime heating conditions, the seasonal thermal frontal zone appears in Lake Ladoga. It features high horizontal water temperature gradients. The coastal waters, stably stratified in density, interact with the waters of the open lake that are unstably stratified because of the free convection developing in the temperature range between 0°C and the maximum density of the water at 4°C. In Lake Ladoga, the advance of the vernal frontal zone lasts about 7?C8 weeks from mid-May to the beginning of July. Both the water temperature and air temperature distributions over the water??s surface show that large spatial temperature ranges exist in the vernal front reaching more than 11°C. We investigated the spatial horizontal gradients of the water??s surface and the air temperature using a spatial grid with a resolution of 5 km. The surface water temperature and the air temperature gradients were compared with each other as well as with the temperatures in the region of varying depths. During the spring peak of the frontal activity in Lake Ladoga, most of the fronts feature mean temperatures greater than 4°C. This indicates that the thermal bar marks the offshore edge of the most extensive frontal zone.     

Methodological Approaches and Results of an Analysis of the Climatic Seasonal Course of Stable Stratification Parameters of a Dimictic Lake (Case Study of the Central Part of Lake Ladoga)

Izvestiya, Atmospheric and Oceanic Physics - On the basis of general physical concepts of the thermic of a dimictic lake and the proposed methodological developments, the average climatic course of...