Removing some cloud seeds of doubt

February 01, 2009

A team of researchers at Monash University has released a new analysis of precipitation records from the long-term cloud seeding operation in Tasmania that shows a promising increase in rainfall during periods of seeding.

The team worked with Hydro Tasmania analysing the cloud seeding activity over the hydroelectric catchment area in central Tasmania for more than four decades - from 1960 - 2005.

Associate Professor Steven Siems, Faculty of Science said the analysis used monthly rainfall figures in the catchment area where the seeding took place and compared it with data from nearby control areas.

"A number of independent statistical tests showed a consistent increase of at least 5% in monthly rainfall over the catchment area. This is the first time that an independent analysis of cloud seeding data over several decades has shown a statistically significant increase in rainfall," Associate Professor Siems said.

However, the team of Monash scientists have also cautioned against becoming too excited by the initial results.

Anthony Morrison, a PhD candidate on this research said the clouds over the Southern Ocean and Tasmania are unique in that they can contain vast amounts of supercooled liquid water and are unusually clean.

"They're really not comparable to clouds that have been seeded anywhere else in the world. Further field measurements of cloud microphysics over the region are needed to provide a physical basis for these statistical results," Mr Morrison said.

Associate Professor Siems said the statistical analysis of the data suggests positive results from cloud seeding but more research needs to be done.

"We need to support our findings with a greater scientific understanding. There could be other explanations for the increased rainfall - although we suspect that cloud seeding is a significant contributor," Associate Professor Siems said.

The practice of cloud seeding remains a contentious issue in the scientific community with many attempts having been made since the beginning of cloud seeding programs in the 1940s to measure and explain rainfall levels. Tasmania has long been a location for cloud seeding programs, following apparent success with the programs in the 1960's and 1970's when significant rainfall increases of more than 30 per cent were measured and reported by CSIRO scientists.
-end-
Professor Steve Siems is available for interview on: 0432 740 237

PhD candidate Anthony Morrison is available for interview on: 0401008676

For more information please contact Samantha Blair, Media & Communications + 61 3 9903 4841 or 0439013 951

Monash University

Related Rainfall Articles from Brightsurf:

Study projects more rainfall in Florida during flooding season
A new study by researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science projects an increase in Florida's late summertime rainfall with rising Atlantic Ocean temperatures.

Importance of rainfall highlighted for tropical animals
Imagine a tropical forest, and you might conjure up tall trees hung with vines, brightly colored birds, howling monkeys, and ... rain.

New study could help better predict rainfall during El Niño
Researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science have uncovered a new connection between tropical weather events and US rainfall during El NiƱo years.

Mediterranean rainfall immediately affected by greenhouse gas changes
Mediterranean-type climates face immediate drops in rainfall when greenhouse gases rise, but this could be interrupted quickly if emissions are cut.

Future rainfall could far outweigh current climate predictions
Scientists from the University of Plymouth analysed rainfall records from the 1870s to the present day with their findings showing there could be large divergence in projected rainfall by the mid to late 21st century.

NASA estimates Imelda's extreme rainfall
NASA estimated extreme rainfall over eastern Texas from the remnants of Tropical Depression Imelda using a NASA satellite rainfall product that incorporates data from satellites and observations.

NASA estimates heavy rainfall in Hurricane Dorian
Hurricane Dorian is packing heavy rain as it moves toward the Bahamas as predicted by NOAA's NHC or National Hurricane Center.

NASA looks at Barry's rainfall rates
After Barry made landfall as a Category 1 hurricane, NASA's GPM core satellite analyzed the rate in which rain was falling throughout the storm.

NASA looks at Tropical Storm Barbara's heavy rainfall
Tropical Storm Barbara formed on Sunday, June 30 in the Eastern Pacific Ocean over 800 miles from the coast of western Mexico.

NASA looks at Tropical Storm Fani's rainfall rates
Tropical Storm Fani formed in the Northern Indian Ocean over the weekend of April 27 and 28, 2019.

Read More: Rainfall News and Rainfall 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.