What factor defines all groups in the Köppen system, with the exception of dry climates? temperature precipitation air pressure evaporation

When air at the surface diverges, airflow above must diverge, regardless of hemisphere converge in the northern hemisphere but diverge in the southern diverge in the southern hemisphere but converge in the northern converge, regardless of hemisphere?

What is a compass? how does it work

What is an additional type of erosion found at the coast? what does it mean?