Question

shortly reason some computeer models that indicate that global wARMING MIGJT INCREASSE CLOUD COVER, and how might this effect atmosphric processes

Answer 1

Short answer
Some climate models (GCMs and higher-resolution cloud-resolving models) predict increased cloudiness in parts of the atmosphere as the planet warms. The basic reasons are thermodynamic (more moisture) plus dynamical changes in convection and large‑scale circulation. The net impact is uncertain because cloud type and altitude matter a lot.

Why some models project more clouds
- Clausius–Clapeyron: warmer air holds ~7% more water vapor per °C, supplying more moisture for cloud formation.
- Stronger convection: added moisture and surface heating can intensify convective updrafts, increasing convective clouds and anvil anvils in the tropics.
- Circulation shifts: expansion/shift of the Hadley cell and storm tracks moves cloud bands geographically, producing increases in some regions.
- Higher-resolution models: cloud-resolving and regional models resolve convective cloud systems better and often show increased cloud fraction compared with coarse GCM parameterizations.
- Microphysics and aerosols: changes in aerosol concentrations and cloud microphysics can change cloud droplet numbers and lifetimes, sometimes giving more persistent cloud cover.

How increased cloud cover would affect atmospheric processes
- Radiative balance: high thick clouds trap outgoing longwave (warming effect); low bright clouds increase albedo and reflect sunlight (cooling effect). Which dominates controls feedback and surface warming.
- Precipitation and hydrology: more (or more intense) convective clouds change rainfall patterns — often more intense downpours and altered regional totals.
- Latent heat release: extra condensation releases latent heat, changing vertical stability and driving circulation and storm energetics.
- Circulation feedbacks: altered cloud heating profiles can strengthen or weaken jet streams, monsoons and the Hadley circulation.
- Boundary-layer processes: changes in low-cloud cover affect surface temperatures, evaporation, and near‑surface stability.
- Climate sensitivity uncertainty: cloud changes are the largest source of spread in model estimates of equilibrium climate sensitivity.

Bottom line: many models show increased cloudiness somewhere in a warmer world, but the type, altitude and regional pattern determine whether that amplifies or damps warming, so cloud feedbacks remain a major uncertainty.