Since the 1950s, the Tibetan Plateau has seen significant warming and increased precipitation. Despite this overall trend toward wetter conditions, the risk of drought has not necessarily decreased. In fact, the combination of rising temperatures and periodic droughts—known as compound hot-dry events—has become a growing concern. These events, which involve high temperatures and dry conditions happening at the same time, can harm ecosystems, reduce water availability, speed up glacier melting, and increase the risk of landslides and ice avalanches. A new study published in the Journal of Geophysical Research: Atmospheres by Professor Tianjun Zhou's team at the Chinese Academy of Sciences has provided important insights into these compound hot-dry events. The research shows that large-scale climate patterns influence weather conditions on the plateau, leading to alternating periods of hot and dry summers versus cool and wet ones. The team used detailed weather data and climate models to analyze the frequency and patterns of these extreme events since 1979. The study found that the El Niño-Southern Oscillation (ENSO), a major climate pattern in the Pacific Ocean, plays a key role in shaping these events. During El Niño years, when ocean temperatures in the eastern Pacific are warmer than average, the number of compound hot-dry days on the southwestern Tibetan Plateau increases by about 1.85 days. In contrast, during La Niña years, when those ocean temperatures are cooler, the number of such days decreases by about 1.13 days. The impact is even stronger during more intense ENSO events. The researchers also identified differences between two types of ENSO: the eastern Pacific (EP) and the central Pacific (CP). During EP El Niño events, parts of the southwestern plateau can see more than seven additional hot days and 11.4 more drought days. This is linked to changes in cloud cover and solar radiation, which increase the energy absorbed by the land. On the other hand, during CP La Niña events, the number of hot and drought days decreases by about 6.2 and 8.2 days, respectively, due to changes in cloud cover and surface reflectivity that reduce the energy reaching the land. Another important climate factor influencing hot-dry events is the Summer North Atlantic Oscillation (SNAO), which affects weather patterns over the eastern Tibetan Plateau. Changes in the SNAO can influence atmospheric conditions through complex wind patterns that stretch across the Eurasian continent. During the positive phase of the SNAO, compound hot-dry events become more frequent in the eastern plateau. In the more humid southeastern part of the plateau, reduced cloud cover allows more sunlight to warm the land, while in the drier northeastern region, clear skies and reduced radiation under sunny conditions drive the warming. Despite these differences, both areas face increasing heat and dryness.