Determining Why Only Certain Clouds Produce a Lot of Rain

Over the centuries, experts have noticed that only certain clouds produce massive amounts of rain, while others produce only limited or moderate precipitations. Experts with the American space agency and colleagues from other research groups are coordinating a large scale effort to clear up this mystery.

NASA is apparently very interested in this line of research, and this is why it authorized the use of several research planes in a new scientific campaign. During the investigation, the aircraft will fly through and over rain clouds, in a bid to determine what makes some of them special.

Each of the airplanes will be outfitted with a suite of scientific instruments suitable for this type or research. At the same time, groups on the ground will be conducting standard rainfall measurements.

At the end of the study period, the two datasets will be cross-referenced, and investigators will test to see whether patterns emerge from this comparison. This will be the most comprehensive study of its type ever conducted in the United States.

It will centralize data from aircraft, satellites ground sensors and remote-sensing technologies into a single, integrated view of how clouds develop, and how some get to store so much water.

The studies will be carried out between April and June, and will focus mostly on convective clouds, the type in which warm and moist air rises to high altitudes, and then condenses. This class of clouds includes cumulus and cumulonimbus clouds.

“Because precipitation is so critical to our daily existence, we naturally would like to know how much rain falls at any given place and time,” explains NASA Marshall Space Flight Center (MSFC) scientist Walt Petersen, the leader of the space agency's component in the campaign.

“Our goal is to observe and measure the entire precipitation process, from the ice that forms near the tops of clouds to the rainfall that ends up on the ground,” he goes on to say.

“Convective cloud processes play a critical role in our daily lives,” adds meteorologist Michael Jensen, who leads the Department of Energy's (DOE) component of the Mid-latitude Continental Convective Clouds Experiment (MC3E).

“To represent these cloud systems in computer models of the atmosphere, we need to understand the details of why these clouds form, where they form, how they grow and shrink, and what factors control the amount of rain that falls from them,” he explains.

“MC3E will provide insights into all of these questions,” the expert concludes.