In 2009, a similar study had been conducted with just on-the-ground and satellite data, said DeMott, but because it lacked the cloud sampling it was more difficult to understand what was actually happening with the dust in the atmosphere.
Climate change a factor
Spackman, the NOAA researcher, said the scientific community often debates the quality of aerosol measurements taken from clouds, but because the authors used multiple data sources, he said, this strengthened their interpretation. "The complementary meteorological and satellite data and interpretation provided by the authors strengthen the case that dust from disparate global sources can enhance precipitation in certain meteorological environments," Spackman wrote in an email.
Overall, Spackman said, the study makes a strong contribution.
"This is a cutting-edge study in the field of cloud-aerosol-precipitation interactions that includes an interdisciplinary group of atmospheric chemists and meteorologists," he said. "It contributes directly to a number of key science questions on the impact of aerosols on clouds and precipitation."
Climate change is likely to influence rainfall patterns in the Sierra Nevada as well as the amount of dust that makes its way into the atmosphere, so the hope is that a better understanding of how aerosols affect precipitation will help water managers in the future.
"Understanding which factors lead to more or less [precipitation] and how this happens is critical to developing infrastructure to capture more water, reduce flooding, et cetera," Kimberly Prather, a study author who holds appointments at the Scripps Institution of Oceanography and the department of chemistry and biochemistry at UC San Diego, wrote in an email.
Prather added that the results from this study can improve climate models by clarifying the roles of aerosols on precipitation. As the climate warms, researchers expect more dusts to make their way aloft, possibly having impacts on precipitation by changing where rain or snow falls.
The study was part of the CalWater research program, whose goal is to help Western states better understand how their water supply might be altered under climate change. A follow-up will be done in the winter of 2015, Prather said.
"Hydropower is an essential source of electricity in California providing, on average, 15 percent of our annual generation," California Energy Commission Chairman Robert Weisenmiller said in a news release on the study. "This state-funded study in cooperation with NOAA will help us understand how small particles in the air affect precipitation and hydropower generation. Additionally, this information will be useful in estimating the effects of our changing climate."
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500