These plots aid in tracking the location, intensity, and evolution of the eastern Pacific and eastern Atlantic Inter-Tropical Convergence Zone (ITCZ). [This is one technique of many used to track the ITCZ; others include plotting vertical velocity, divergence, rainfall, etc. This product uses geosynchronous satellite imagery and therefore has the advantage of full coverage in space and frequent coverage in time. It uses cloud top temperatures as a proxy for surface convergence.]

The top plot shows the latest infrared (IR) brightness temperatures from GOES Channel 4, where colder temperatures are shown in lighter colors.. To the left of the IR image is a zonal (E-W) mean of those temperatures, smoothed to 1° resolution. 1 and 2 standard deviations (1σ and 2σ) from the domain average are shown as vertical dashed lines and help identify significant cold cloud-top bands.

The bottom plot is a Hovmoller (time-latitude) diagram of the zonal mean brightness temperatures, newest time on the bottom. This allows you to track the evolution of the ITCZ(s).