Cryosols as a test of our knowledge of Earth as a system: Review

摘要

Cryosols are a key component of the cryosphere and, therefore, play a major role in the earth's energy, water, and geochemical cycles. Several examples are given to demonstrate how Cryosols have contributed to our increased understanding of earth's dynamic systems. Cryosols may account for up to 50% of the global soil organic carbon pool. Atmospheric temperatures have increased by +3°C over the past decades in arctic and Antarctic regions. Based on studies of active-layer dynamics and carbon budgets, continued warming may initiate a positive feedback mechanism whereby carbon stored in the near-surface permafrost may be released to the atmosphere as C02. Polar soils and the underlying permafrost are a major source of other biospheric greenhouse gases, including CH4, and N_2O. Radioactive fallout, toxic metals, and other anthropogenic pollutants have accumulated in polar soils and have impacted terrestrial, aquatic, and marine ecosystems. Polar soils are important for studying extremophiles such asendolithic lichens in Antarctica and microorganisms in 2-8 million-year-old permafrost in Siberia and Antarctica. Antarctic soils have been used for interpreting features and processes on Mars, including patterned ground, thermokarst, and rock glaciers.Finally, polar soils are an important component of environmental observatories and provide a data repository for studying environmental change.