Why are there clouds over the Intertropical Convergence Zone?

AI Thread Summary
The Intertropical Convergence Zone (ITCZ) is characterized by the convergence of northeast and southeast trade winds, typically located just north of the equator. This zone is associated with low pressure and is marked by a band of clouds. The presence of clouds in the ITCZ is due to the moisture carried by the trade winds, which originate from around 30° latitude. As these winds travel toward the equator, they rise, causing a decrease in temperature and an increase in relative humidity. This process leads to the formation of small water droplets, which appear as clouds. The absence of larger droplets and ice crystals is attributed to the low temperatures and lack of nucleation sites. The discussion also references the Hadley cell, where rising warm air cools and moisture condenses to form clouds, a phenomenon observed with approaching fronts.
Hall
Messages
351
Reaction score
87
Intertropical Tropical Zone is the zone where north-east and south-east trade winds converge. This zone usually occurs over (I don’t know if “on” should be here) the equator.

In the book The Atmosphere: An Introduction to Meteorology by Lutgens and Tarbuck (13th Edition), Figure 7.9 reads
The Intertropical convergence zone (ITCZ) . This zone of low pressure and convergence is seen as a band of clouds that extends east-west slightly north of the equator.

I cannot understand why are there clouds over the ITCZ. First of all, the clouds are very small water droplets at temperature well below freezing points, that implies that coming trade winds have to have moisture in them. But here is a delicate point which I haven’t understood by reading books, and I believe only by an experienced man that I can get my bridges built up (or get them repaired), how do moist winds cause cloud formation? Here is the scenario: the wind had begun from, almost, ##30^{\circ}## latitude, picked up moisture somewhere in between and reached the equator. At the equator, it may rise up and thus relative humidity reaches its maximum level. The decrease in temperature as the air rises cause the moisture in coming trade winds to form droplets, and due to absence of any nucleui, large droplets and ice crystals are not formed. These droplets at low temperatures is what we see as clouds.

Is my explanation acceptable?
 
Earth sciences news on Phys.org
In a convergence one mass of air willl usually ride up the frontal edge of the other, the warm air rising over the cooler air of a cold front. Rising air cools. Moisture then forms water droplets, which form clouds.
You see this with an approaching front.
 
Hello, I’m currently writing a series of essays on Pangaea, continental drift, and Earth’s geological cycles. While working on my research, I’ve come across some inconsistencies in the existing theories — for example, why the main pressure seems to have been concentrated in the northern polar regions. So I’m curious: is there any data or evidence suggesting that an external cosmic body (an asteroid, comet, or another massive object) could have influenced Earth’s geology in the distant...
On August 10, 2025, there was a massive landslide on the eastern side of Tracy Arm fjord. Although some sources mention 1000 ft tsunami, that height represents the run-up on the sides of the fjord. Technically it was a seiche. Early View of Tracy Arm Landslide Features Tsunami-causing slide was largest in decade, earthquake center finds https://www.gi.alaska.edu/news/tsunami-causing-slide-was-largest-decade-earthquake-center-finds...
Back
Top