Spatial and Temporal Analysis of Copernicus Global Land Service Data-Based Surface Water Temperature of Lake Sevan and Its Relationship with Selected Climatic Variables Over the Period 2017–2023

Lakes as ecosystems are sensitive to climatic variables, with Lake Surface Water Temperature affecting lake ecosystem health. This study analyzes the spatial and temporal dynamics of Lake Surface Water Temperature in Lake Sevan—Armenia’s largest freshwater body—using Copernicus Global Land Operations (C-GLOPS) data from 2017–2023. It investigates the C-GLOPS lake surface water temperature relationship with climatic variables (e.g., air temperature, solar radiation). The study aims to characterize Lake Surface Water Temperature fluctuations and assess their correlations with climate drivers. Key methods include time series analysis using the Mann–Kendall test and Sen’s slope estimator, linear correlation analyses, and Mean Shift Segmentation to detect spatial Lake Surface Water Temperature patterns. C-GLOPS data-based findings reveal Lake Surface Water Temperature exceeds air temperature in winter (December–March), with solar radiation dominating from February to July. Air and water temperatures align in spring, peaking in July, while solar radiation peaks in August. The seasonal trends are consistent. Time-lag effects are evident; early-year air temperatures influence Lake Surface Water Temperature later in the year. Spatially, two main clusters (Big and Small Sevan) are visible in winter, merging by spring. Summer shows diverse thermal zones, which stabilize by late autumn. Overall, the study reveals a complex but measurable link between Lake Surface Water Temperature and climatic variables and using C-GLOPS data for monitoring can help enhance understanding of how climatic variables affects lake systems.