The cryosphere is the portion of the Earth's surface that is permanently or seasonally frozen, including ice sheets, glaciers, ice caps, snow cover, permafrost, and sea ice. It plays a critical role in regulating the Earth's climate and is closely linked to other Earth systems, such as the atmosphere, oceans, and biosphere. Research in the cryosphere focuses on understanding the processes and interactions within this frozen environment, as well as the impacts of climate change on the cryosphere and broader global systems. This research area is important for predicting future environmental changes and developing strategies for mitigating the effects of climate change.