The Curonian Lagoon is a shallow freshwater lagoon of significant environmental value in the south-eastern part of the Baltic Sea. The objective of the study was to evaluate changes of ice indices (duration, thickness and breakup dates) of this lagoon and to assess their possible tendencies in the 21st century. A methodology was developed combining the assessment of past changes (1960–2017) of ice indices and their projections in the near (2021–2040) and far (2081–2100) future periods using a hydrometeorological database, statistical methods and regression analysis as well as regional climate models and RCP scenarios. Climate change has a considerable impact on ice conditions in the Curonian Lagoon. During the historical period of 1960–2017, the Curonian Lagoon was covered with ice for 72 days a year, ice thickness reached 23 cm, whereas ice breakup was observed in the middle of March on average. According to the different scenarios, in the near and far future periods, ice duration will last 35–45 and 3–34 days, respectively. Ice thickness is projected to be 13–15 cm in the near future, whereas, at the end of the century, it is expected to decline to 0–13 cm. In the past, the lagoon ice cover remained until the middle of the third decade of February. At the end of the 21st century, RCP8.5 scenario projects the most drastic shifts: the permanent ice cover might be absent, whereas short-term ice cover is expected to melt already in the beginning of January.

库尔斯沙嘴泻湖是在波罗的海东南部具有重要环境价值的浅水泻湖。该研究的目的是评估该泻湖的冰指数变化（持续时间，厚度和破裂日期），并评估其在21世纪的可能趋势。结合水文气象数据库，统计方法和回归分析，开发了一种方法，该方法结合了对冰指数的过去变化（1960–2017）的评估及其在近期（2021–2040）和远期（2081–2100）未来的预测。作为区域气候模型和RCP情景。气候变化对库尔斯沙嘴泻湖的冰况有很大影响。在1960–2017年的历史时期，库尔斯泻湖一年被冰层覆盖72天，冰层厚度达到23厘米，而在三月中旬，平均观察到冰破裂。根据不同的情况，在不远的将来，冰的持续时间将分别持续35-45天和3-34天。预计不久的将来，冰的厚度将为13–15厘米，而到本世纪末，预计它将降至0–13厘米。过去，泻湖的冰盖一直保留到2月的第三个十年中期。在21世纪末，RCP8.5情景预测了最剧烈的变化：永久性冰盖可能不存在，而短期冰盖预计将在1月初融化。预计不久的将来，冰的厚度将为13–15厘米，而到本世纪末，预计它将降至0–13厘米。过去，泻湖的冰盖一直保留到2月的第三个十年中期。在21世纪末，RCP8.5情景预测了最剧烈的变化：永久性冰盖可能不存在，而短期冰盖预计将在1月初融化。预计不久的将来，冰的厚度将为13–15厘米，而到本世纪末，预计它将降至0–13厘米。过去，泻湖的冰盖一直保留到2月的第三个十年中期。在21世纪末，RCP8.5情景预测了最剧烈的变化：永久性冰盖可能不存在，而短期冰盖预计将在1月初融化。