Landatmosphere

Landatmosphere refers to the two-way interactions between the land surface and the overlying atmosphere. Through exchanges of energy, water, momentum, and, to a lesser extent, carbon, the land surface influences near-surface temperature, humidity, and wind, while atmospheric conditions control surface fluxes and soil moisture via precipitation and radiative inputs. The response of the land surface depends on properties such as soil moisture, vegetation cover, surface albedo, roughness, and land use.

Key processes include the surface energy balance, where solar radiation heats the surface and drives sensible heat and latent heat fluxes; evapotranspiration from soil and vegetation links soil moisture to humidity; the boundary layer development; and albedo and roughness controlling how much solar energy is absorbed and momentum is exchanged. Soil moisture acts as a memory for the system and modulates heat waves and droughts and can feed back to precipitation through moisture availability.

Observations and models: Eddy covariance towers and flux measurements monitor surface fluxes; satellite remote sensing provides soil moisture, evapotranspiration, and land cover data. Land surface models and coupled atmospheric models simulate the two-way coupling, with metrics such as coupling strength, evaporative fraction, and Bowen ratio used to diagnose interactions; uncertainties arise from subgrid heterogeneity and representation of vegetation dynamics.

Applications and importance: Accurate land-atmosphere representation improves weather forecasts, seasonal climate projections, drought monitoring, and water resource management. Human activities altering land cover and soil moisture, such as urbanization, agriculture, and deforestation, modify albedo, roughness, and evapotranspiration, thereby changing local to regional climate.