The science of cloud seeding

June 01, 2016

Experiments to seed clouds and coax them to produce more rain started 70 years ago. Early practitioners claimed a 10 percent boost in precipitation, but their studies lacked statistical rigor. The science of rainmaking has evolved since then -- but how reliable is it now? An article in Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society, takes a look.

Janet Pelley, a contributing editor at C&EN, reports that for cloud seeding science to come into its own, it needs to address some major challenges. To start, scientists have yet to understand a critical step in natural rainmaking: ice nucleation. This process involves water vapor freezing onto particles, which leads to precipitation. Another significant glitch in experimenting with seeding is the difficulty with running controlled experiments in real clouds. Once a cloud is treated, scientists can't measure how much rain it would have produced if left alone.

To chip away at these obstacles, scientists have developed more sophisticated experiments and simulations using sensing tools and computer models. Recent multi-year studies have found hints that seeding might yield a boost in precipitation. But results weren't statistically significant. Remote sensing is giving scientists a better view into cloud dynamics in real time and could help advance the science. As dozens of countries invest millions of U.S. dollars in cloud seeding, the new studies could be well worth the effort.
-end-
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Follow us: TwitterFacebook

American Chemical Society

Related Precipitation Articles from Brightsurf:

Convection-permitting modelling improves simulated precipitation over the Tibetan Plateau
A China-UK research team explains the possible reasons for excessive precipitation over the TP in the mesoscale convection-parameterized models.

Spread of monsoon circulation changes explains uncertainty in global land monsoon precipitation projection
A new study emphasizes the importance of reliable prediction of circulation changes, to ensure that future projections of global land monsoon are suitable for use by policy makers.

GMMIP simulations on global monsoon interannual variability show higher skill than historical simulations
GMMIP simulations on global monsoon interannual variability show higher skill than historical simulations.

The spatial consistency of summer rainfall variability between the Mongolian Plateau and North China
The regional differences and similarities of precipitation variability are hotspots in climate change research.

Scientists find key factors impacting sideswiping tropical cyclone precipitation
Scientists find that the distribution of sideswiping tropical cyclones precipitation(STP) includes extreme STP events that appear not only over the island and coastal areas, but also over inland areas

Rainy season tends to begin earlier in Northern Central Asia
The researchers found robust increase of annual mean precipitation at the end of the 21st century under all modelling scenarios over northern central Asia.

Using cloud-precipitation relationship to estimate cloud water path of mature tropical cyclones
Scientists find the cloud water path of mature tropical cyclones can be estimated by a notable sigmoid function of near-surface rain rate.

Precipitation will be essential for plants to counteract global warming
A new Columbia Engineering study shows that increased water stress--higher frequency of drought due to higher temperatures, is going to constrain the phenological cycle: in effect, by shutting down photosynthesis, it will generate a lower carbon uptake at the end of the season, thus contributing to increased global warming.

Fall precipitation predicts abundance of curly top disease and guides weed management
Transmitted by an insect known as the beet leafhopper, curly top disease is a viral disease affecting many crops, including melons, peppers, sugar beets, and tomatoes.

Study confirms climate change impacted Hurricane Florence's precipitation and size
A new modeling framework showed that Hurricane Florence produced more extreme rainfall and was spatially larger due to human-induced climate change.

Read More: Precipitation News and Precipitation Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.