The weather patterns on earth are shown in this image. explain why there are convection currents; why there are hotter and colder parts of earth.

Conventional currents move heat from one place to the next through the notion of mass with fluids like water. The transfer, therefore, drives the currents in the ocean through the atmospheric weather.

The current occurs because of the heated fluid, which increases and becomes less dense. Then the vapor rises in a far distance from the heat. While lifting, it pulls more cool liquid and finally establishes the currents which are only stopped through spreading of the heat evenly in the fluid.