This article aims to analyze the dynamics of freezing and thawing of Antarctic lakes located in ice-free areas on Nelson Island and Fildes Peninsula, where response to changes in air temperature and precipitation rates occur rapidly, during the period from July 2016 to December 2018. In these places, which are difficult to access, remote sensing is an important alternative, especially considering the use of active remote sensors such as the Synthetic Aperture Radar (SAR), which has less restriction regarding the presence of clouds over the study area. Three backscatter thresholds were defined (σ) for the identification of the physical state of the water of the lakes of the study region, applied in Sentinel 1A SAR (S1A) images under Horizontal Horizontal (HH) polarization and Interferometric Wide (IW) imaging mode. These images, along with the air temperature data obtained by the Interim Re-Analysis (ERA-Interim) atmospheric reanalysis model, provided the evidence for the interpretation of the freezing and thawing periods of the lakes. The thresholds applied for the definition of the physical state of the lake water were greater than − 14 dB for frozen water, between − 14 and − 17 dB for the surface, with up to 60% of their frozen area, and less than − 17 dB for open water. The temporal analysis revealed that the lakes start to thaw in October, become completely thawed in February, and freeze again in March. Nevertheless, it can be said that the S1A satellite allows a satisfactory identification of the liquid and solid phases of the water in the lakes of the study region.

本文旨在分析位于Nelson岛和Fildes半岛无冰地区的南极湖的冻结和融化动态，这些区域在2016年7月至2018年12月期间对气温和降水率的变化迅速做出了响应。在这些难以接近的地方，遥感技术是重要的替代选择，尤其是考虑到使用有源遥感器（例如合成孔径雷达（SAR））时，对研究区域内云的存在的限制较少。定义了三个反向散射阈值（σ）以识别研究区域的湖泊水的物理状态，应用于水平水平（HH）极化和宽幅干涉（IW）成像模式下的Sentinel 1A SAR（S1A）图像中。这些图像以及通过临时再分析（ERA-Interim）大气再分析模型获得的气温数据，为解释湖泊的冻融期提供了证据。用于定义湖水物理状态的阈值对于冷冻水而言大于-14 dB，对于表面而言介于-14和-17 dB之间，其冷冻面积最多为60％，小于-17 dB用于开阔水域。时间分析显示，湖泊在10月开始融化，2月完全融化，3月再次冻结。不过，