One-year experiment to study clouds launches at La Jolla’s Scripps Pier and Mount Soledad

Objects floating in the sky have been in the news a lot lately, and many more will be seen over La Jolla in the next year.

But these won’t be so mysterious.

More than 1,400 weather balloons will be sent into the atmosphere from La Jolla’s Scripps Pier at a rate of four per day to gather data for a study of clouds to help scientists project future climate change.

On Feb. 13, researchers and representatives of the U.S. Department of Energy gathered at the pier to showcase their instruments and launch the first weather balloon.

The Eastern Pacific Cloud Aerosol Precipitation Experiment (known as EPCAPE) is being conducted at Scripps Pier and near the top of Mount Soledad, also in La Jolla. The experiment continues through February 2024.

Instruments have been posted at both sites to conduct real-time research of stratocumulus clouds to improve their representation in science models and help answer three key questions:

• What are the seasonal and diurnal cycles of marine stratocumulus clouds and aerosol properties of the northern Pacific coast?
• How do cloud properties change as winds push coastal clouds inland?
• Will retrieved cloud properties reflect the regional signatures of aerosol?

This is some of the equipment being used as part of the Eastern Pacific Cloud Aerosol Precipitation Experiment.

(Ashley Mackin-Solomon)

Department of Energy program manager Shaima Nasiri said the overall project “is really trying to better understand the processes and properties of marine low clouds,” which are common off the west coasts of continents and “have an incredible impact on Earth’s climate.”

Dan Lubin, a research physicist and senior lecturer at UC San Diego’s Scripps Institution of Oceanography, looked around at the clouds in view and said: “These clouds are a very key component of the climate system. The lower clouds that form extensively over the eastern Pacific cool the atmosphere. And not only that, the modulation of energy at the Earth’s surface is caused by the presence or absence of these clouds.”

The role of these clouds in local and global climate models has been theoretical so far, Lubin said, and the measurements taken with the instruments in the study will provide real data.

“While the models are very sophisticated, they need experimental knowledge to make them work,” Lubin said. “If the clouds aren’t represented properly, then the climate models are simply going to get things wrong because the fundamental physics and chemistry going into them is not right. That’s the goal of EPCAPE, to really understand these clouds from first principles with hard data that we can then use to improve our ability to project future climates.”

Examples of that data include the processes that build and sustain clouds and the role of nano-size aerosols in the life cycle of a cloud.

Storage bins posted along Scripps Pier house research equipment as part of a one-year cloud study.

(Ashley Mackin-Solomon)

“These instruments [at the Department of Energy’s Atmospheric Radiation Measurement facility, or ARM] measure these processes, which is something we just haven’t had here,” Lubin said. “The data set is really going to give us a lot of insights. I think it will lead to some fundamental improvements in our ability to project future climate.

“We’ll also make some improvements in our ability to predict clouds for local weather events that are important, like heat waves. It’ll just increase our knowledge from basic principles. It’s really unprecedented.”

A weather balloon will be launched every six hours every day of the experiment to provide detailed data about the structure of the entire atmosphere as it changes throughout the day, Lubin said.

A weather balloon ascends over La Jolla on Feb. 13. It will send atmospheric information to instruments on Scripps Pier.

(Ashley Mackin-Solomon)

Though a moderate size while on the ground, a balloon will expand as it enters the atmosphere and reach the size of a small bus.

The Mount Soledad site plays a role in the study in that it is high enough to sometimes actually be in the clouds.

The concept for the Soledad location was presented to the La Jolla Community Planning Association last year. At the time, Scripps Oceanography professor Lynn Russell said the research that will be conducted there “will be super important for science because we will be collecting information about this eastern Pacific cloud deck that extends for hundreds of miles over the ocean and interacts with our coastline. We want to understand how climate change is affecting that super-important cloud deck that keeps us cooler in the summer and warmer in the winter … and how this region will fare as the climate changes.”

The presence of pollution from Long Beach and Los Angeles in marine aerosols will be studied for “how those different types of atmospheric particles are interacting with the clouds and affecting their lifetime and affecting the size of the particles,” Nasiri said.

“These are critical processes for us to incorporate in our numerical weather prediction models in our climate models,” she said. “We need to really understand all the points of these processes so that if anything changes, we can model it.” ◆