Which situation does not involve convection?

The situation involving sunlight warming the ground does not include convection because it primarily occurs through the process of radiation. Radiation involves the transfer of heat energy through electromagnetic waves, not requiring any medium like air or water for the transfer. In this case, sunlight directly warms the surface of the ground, and the heat is not moved by physical movement of particles or fluid, which is characteristic of convection.

In comparison, the other scenarios incorporate convection processes. Heating water in a kettle involves heat being transferred through the water, causing currents or movements within the fluid; feeling warmth from a heater typically involves warm air rising and cooler air being drawn in to replace it, creating a convective cycle; and using a metal spoon to stir soup enhances the heat distribution of the soup through the physical motion of the liquid itself, promoting convection movement.