葫芦影

Atmospheric Scientists Study Under-Researched Role of Clouds in Regulating Earth鈥檚 Temperature

Yunsoo Choi Uses Data from TRACER, a Meteorological Experiment in Houston

When you look up at the sky and examine the color and shape of the clouds, you can likely judge whether rain is on the way. Not only do clouds release showers, snow, hail and other kinds of precipitation, but they also hold crucial information to better understand the earth鈥檚 climate.

Clouds
Choi and his students鈥 research could be used by climate scientists to better understand the role of clouds on the global temperature.

葫芦影业 Associate Professor of Earth and Atmospheric Sciences Yunsoo Choi is studying the interaction between clouds and aerosols, the tiny particles that comprise clouds, and how cloud formation and location in the atmosphere maintains the earth鈥檚 temperature. Choi was awarded a $550,728 grant from the Department of Energy鈥檚 Office of Science to fund his and his graduate students鈥 work over the next three years.

鈥淐louds cover about 70% of the earth鈥檚 surface,鈥 said Choi, a faculty member in the UH College of Natural Sciences and Mathematics. 鈥淭hey are one of the most essential components of the global climate system because of their regulation of surface precipitation and the atmosphere's radiation balance.鈥

Yunsoo Choi
Yunsoo Choi is associate professor in the Department of Earth and Atmospheric Sciences at the UH College of Natural Sciences and Mathematics.

Radiation balance is the difference between the amount of solar radiation absorbed by earth and the amount released by earth back to space. Different types of clouds can have varying radiative impacts. For example, a large, convective cloud stacked high in the sky may reflect a good amount of sunlight back to space, whereas a shallow, thin cloud in the troposphere may not.

Choi and his group will further investigate how aerosols form these clouds. He explains aerosols can be inorganic, made up of sulfates, nitrates or ammonium, or they can be organic components like black carbon and soil particles.

Aerosols are chemically complicated. Water vapor condenses on their surface and forms cloud condensing nuclei, which are essentially the seeds that grow clouds.

鈥淭he formation of cloud droplets typically cannot occur without aerosols,鈥 said Choi鈥檚 atmospheric science doctoral student Ali Mousavinezhad. 鈥淐louds strongly affect the Earth's energy balance by trapping heat near the surface and reflecting solar radiation back to space.鈥

Their method includes data from Department of Energy-funded Atmospheric Radiation Measurement鈥檚 involving UH researchers. The experiment seeks to answer the question of whether pollution makes thunderstorms more severe by gathering data from storms in the Houston area.

Choi鈥檚 method also includes utilizing data from an aerosol-cloud interaction targeted modeling system.

鈥淔or me, the most interesting aspect of this project is the combination of a modeling system with the dataset from an ongoing campaign, happening right here in our backyard,鈥 said Arman Pouyaei, an atmospheric science doctoral student in Choi鈥檚 group. 鈥淭he idea is to use this dataset in a novel technical approach. We hope to learn important lessons about the capabilities of current modeling frameworks in representing the impacts of aerosols on cloud formation and climate change.鈥

Through the team鈥檚 novel technical approaches, they hope to share information on clouds to climate scientists.

鈥淐limate change is primarily discussed in terms of greenhouse gases,鈥 said Mousavinezhad. 鈥淏y the end of this project, we will gain a deeper understanding of how aerosols as air pollutants influence cloud formation and our planet's climate, which I am very excited about."

- Rebeca Hawley, University Media Relations

Top Stories