Due to global warming, precipitation extremes are becoming more frequent and more severe, further exacerbating the uneven distribution of daily precipitation. In this study, we explored how many days in a year it takes to get to a certain amount of the precipitation that falls annually. We analyzed daily precipitation from gridded observations across the European continent and found that it generally took 22 to 34 of the wettest days to contribute to 50% of yearly totals (WD50). We found various degrees of alignment between gridded observations and ground measurements. Building on this, we examined changes in WD50 and detected widespread shifts toward fewer days in WD50 between the periods of 1950–1985 and 1986–2021. In addition, about one quarter of the European land also exhibited significant, decreasing trends in WD50 over the last 7 decades. Overall, this work showed an intensification of annual precipitation regimes.

This study analyzed the ground conditions that allowed some extreme wildfires in 2017 and 2023 to take such proportions and burn around 750,000 ha across Central Chile. Using publicly available satellite data, we examined the relationship between the burned areas from the Moderate Resolution Imaging Spectroradiometers (MODIS) and their antecedent soil moisture from the Soil Moisture Active Passive (SMAP) mission. We found that a small number of fires were responsible for disproportionately large burned areas and that these megafires (i.e., >10,000 ha) were more likely to exhibit relatively drier conditions in the months and days prior. Based on this, we tested various thresholds in low antecedent soil moisture to identify areas more prone to megafires. By differentiating the moisture conditions below and above 0.14 m³/m³, we were able to map all of the 2017 megafires, at least in part. Our classification balanced the success and errors in prediction, yielding 54.1% recall and 75.9% precision (well above the 56.3% baseline). For 2023, the burned areas could not be classified as accurately, due to differences in pre-fire conditions. Overall, our research provided new insights into the link between satellite-based soil moisture and extreme wildfire events. Among other things, this study demonstrated that certain critical thresholds in SMAP had predictive skill to identify conditions more conducive to megafires. Ultimately, this work can be expanded to other parts of the world in support of enhanced wildfire mitigation and management.

Agroecosystems are facing the adverse effects of climate change. This study explored how the ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) can give new insight into irrigation allocation and plant health. Leveraging the global coverage and 70-m spatial resolution of the Evaporative Stress Index (ESI) from ECOSTRESS, we processed over 200 overpasses and examined patterns over 3 growing seasons across the Maipo River Basin of Central Chile, which faces exacerbated water stress. We found that ECOSTRESS ESI varies substantially based on the overpass time, with ESI values being systematically higher in the morning and lower in the afternoon. We also compared variations in ESI against spatial patterns in the environment. To that end, we analyzed the vegetation greenness sensed from Landsat 8 and compiled the referential irrigation allocation from Chilean water regulators. Consistently, we found stronger correlations between these variables and ESI in the morning time (than in the afternoon). Based on our findings, we discussed new insights and potential applications of ECOSTRESS ESI in support of improved agricultural monitoring and sustainable water management.

Amid intensifying global warming, precipitation regimes become increasingly concentrated on the wettest days. Yet, there remains limited research at the global scale analyzing how half of the annual precipitation falls predominantly on these days. Therefore, we leveraged five of the most notable satellite precipitation products (SPPs) to map the number of wettest days that account for 50% of annual precipitation (WD50) across all oceans and landmasses. We found substantial differences in WD50 between SPPs and further evaluated their ability to capture spatial patterns accurately. Out of the SPPs studied, data from the Integrated Multi‐satellite Retrievals for Global Precipitation Measurement aligned most closely with rain‐gauge measurements. This research also revealed substantial variability in WD50 across reference climate regions, shedding new lights onto the global distribution of WD50—a variable particularly relevant for water resources planning as precipitation regimes are projected to become more unevenly distributed in the future.