Outline 2 key controls on climate in the tropics

The first key control on the tropics are air masses. Air masses are a large body of air in which the horizontal gradients of their main physical properties vary only slightly. They are are high pressure bodies and frequently form in area of uniform surface (such as over oceans). Air masses derive their temperatures and humidity from their source regions. e.g Continental (i.e dry) Tropical air masses. Another key control on tropical climates are ocean currents. Warm currents (heated by intense thermal insolation at the equator) carry water polewards and raise air temperatures in maritime areas (such as coasts). Whilst cold currents bring water to the equator and thus lower the temperature of coastal areas. Thus, coasts opposite warm currents tend to be cool and dry. For reference: https://blogs.egu.eu/geolog/2017/04/12/knowing-the-oceans-twists-and-turns/ https://www.bbc.co.uk/bitesize/guides/zsxcwmn/revision/2