How many major wind systems does the earth have?

How thick is the crust in km? When do you use a copper and hide head mallet? What are structures that form when magma solidifies beneath earth's surface called? What turns Blue cobalt chloride pink and has a boiling point of 100 degrees? What mineral determines magma viscosity? Are tropical storms over land or over water? What is the atomic radius of caesium in nm? What type of plate boundary could form a mountain chain of sedimentary rock? What role do lichens and mosses play in the process of soil formation? Which would corrode first copper or iron? What property might you test by rubbing one mineral directly against another mineral? Which gas is evolved when potassium ferrocyanide crystals are heated with conc. sulphuric acid? What volumes of h2s gas and oxygen are necessary to produce 14.2 l of sulfur dioxide gas the balanced equation is 2 h2s 3 o2 2 so2 2 H2O? Which feature would easily distinguish schist and gneiss from quartzite and marble? What property do all soil horizons share? What kind of animals live in a seasonal forest? The removal of material by erosion will cause the crust to what? Do oil and bleach mix? What is a non example of deposition? Which is the term for the treeless biome in high latitudes that has permafrost- tundra or isotherm?

How many major wind systems does the earth have?