Theoretical study of ice cover phenology at large freshwater lakes based on SMOS MIRAS data

Abstract

Abstract. The paper presents a theoretical analysis of seasonal brightness temperature variations at a number of large freshwater lakes: Baikal, Ladoga, Great Bear Lake (GBL), Great Slave Lake (GSL), and Huron, retrieved from Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) data (1.4 GHz) of the Soil Moisture and Ocean Salinity (SMOS) satellite. The analysis was performed using the model of microwave radiation of plane layered heterogeneous nonisothermal medium. The input parameters for the model were real regional climatological characteristics and glaciological parameters of ice cover of the study lakes. Three distinct seasonal brightness temperature time regions corresponding to different phenological phases of the lake surfaces: complete ice cover, ice melt and deterioration, and open water were revealed. The paper demonstrates the possibility to determine the beginning of ice cover deterioration from satellite microwave radiometry data. The obtained results can be useful for setting the operating terms of winter crossings and roads on ice, as with the beginning of ice deterioration, these transportation routes across water bodies (rivers, lakes, water reservoirs) become insecure and cannot be used any more.

Phenological Phases of Water Bodies in the Boreal and Subarctic Zone of the Northern Hemisphere According to SMOS Satellite Data and Their Relationship with the Seasonal Dynamics of CO2 Concentration in the Atmosphere

“…A continuous archive of SMOS L1C data from 2012 to the present is stored on ESA servers. In works [13,26], based on theoretical modeling of the own microwave radiation of freshwater bodies (lakes, bays) and analysis of brightness temperature measured by the MIRAS radiometer of the SMOS satellite, the possibility of determining seasonal changes in the state of their surface is shown. A comparison of satellite data with model calculations made it possible to identify three time ranges of TBr values for seasonally freezing freshwater bodies: the first range is associated with radiation from an ice-free water surface; the secondwith an ice cover established on the surface of the lakes; and the third range, characterized by a short-term sharp increase in TBr by an amount of about 40-90 K, corresponds to a period of cardinal changes in the structure of the ice cover (a period of intense destruction and melting) (Figure 3).…”

“…A comparison of satellite data with model calculations made it possible to identify three time ranges of TBr values for seasonally freezing freshwater bodies: the first range is associated with radiation from an ice-free water surface; the secondwith an ice cover established on the surface of the lakes; and the third range, characterized by a short-term sharp increase in TBr by an amount of about 40-90 K, corresponds to a period of cardinal changes in the structure of the ice cover (a period of intense destruction and melting) (Figure 3). Seasonal variations in brightness temperature and corresponding phenological phases for Great Slave Lake [26] (see. Table 1).…”

“…Figure3. Seasonal variations in brightness temperature and corresponding phenological phases for Great Slave Lake[26] (see. Table1).…”

Passive Microwave Retrieval of Soil Moisture Below Snowpack at L-Band Using SMAP Observations

“…This intermittency can decrease the accuracy, especially when a binary comparison is adopted through thresholding the FT probabilities. Secondly, when water fraction is high in satellite FOV, the TB time series cyclic structure primarily responds to ice in/out of the water bodies [59] and wetness of the overlying snow cover, which can exhibit higher correlations with air temperatures rather than soil temperatures. These uncertainties are exacerbated considering that the reference currently rests on comparisons Fig.…”

Microwave Satellite Systems for Hydrological Monitoring

“…Появление большого количества трещин и последующее их насыщение жидкой водой изменяет диэлектрические свойства льда -значительно увеличивается поглощение электромагнитного излучения, что вызывает повышение яркостной темпера-туры ледяного покрова и экранирование микроволнового излучения, идущего от водной поверхности. Возможность возникновения данного эффекта подтверждена модельными расчетами в адаптированной для пресноводных озер системе «вода -лед -снег -атмосфера» [15]. Обнаруженный эффект позволяет предсказывать весеннее изменение гидрологического режима крупных пресноводных озер по спутниковым данным L-диапазона.…”