Owing to the opposite vertical orientation with respect to the plane of Earth’s rotation across the equator from the Southern Hemisphere to Northern Hemisphere, the equator serves as a waveguide that houses all kinds of atmospheric waves propagating along the west-east direction, which are referred to as “equatorial waves.” Equatorial waves are generated from spatially non-uniform diabatic heating fields, including latent heating releases from convective storms. These equatorial waves in turn initiate and organize new convections as they propagate out of their genesis locations, triggering a new set of equatorial waves propagating both eastwards and westwards along the equator. As a result, equatorial waves play important roles in organizing large-scale circulation disturbances and regulating large-scale diabatic heating patterns in tropics.