Precipitation on EARTH Magazine

Beryllium: the rain bringeth and the rain taketh away

Thu, 17 Jan 2019 13:39:49 -0500

A study of soils in the Kohala region of Hawaii's Big Island revealed that high rainfall and weathering rates affect the accuracy of beryllium-10 as a tracer of soil age and processes. Credit: Eric Tessmer, CC BY 2.0.

High in Earth’s atmosphere, cosmic rays collide with oxygen atoms, shattering the oxygen into smaller atoms, including radioactive beryllium-10. Atmospheric beryllium-10 that falls to Earth’s surface — in precipitation or aboard dust particles — is known as meteoric beryllium-10. Researchers often use the ratio of meteoric beryllium-10 to nonradioactive beryllium-9 in soil as a tracer of soil age and processes. As beryllium-10 has a long half-life — about 1.4 million years — scientists have used it for studies of both short- or long-term soil dynamics.

Winter precipitation in southwestern U.S. tied to Kiwi Coast

Tue, 16 Oct 2018 10:18:16 -0400

New research suggests a strong negative correlation between fall sea-surface temperatures off the north coast of New Zealand and winter precipitation in the southwestern U.S. If, for example, there are lower-than-normal sea-surface temperatures north of New Zealand, there is a much higher chance for a wet winter in Southern California and the southwestern U.S. Credit: K. Cantner, AGI, after Mamalakis et al., Nature Communications, June 2018.

Water supplies in the southwestern United States largely depend on winter precipitation. Predicting seasonal rain and snowfall is becoming more difficult, however, as climate change causes precipitation patterns to vary. A new study provides evidence of a strong correlation between late-summer to fall sea-surface temperatures off the coast of New Zealand and winter precipitation in the southwestern U.S. — a correlation that could help provide earlier and more reliable forecasts for the southwestern U.S., and improve water resource and ecosystem management in the region.

From silver to snow: Full cloud seeding cycle observed

Tue, 01 May 2018 15:58:44 -0400

A "Doppler on Wheels" truck, equipped with X-band radar, atop Packer John Mountain in the Salmon River Range in central Idaho tracks the formation of ice particles during cloud seeding experiments. Credit: Josh Aikens.

Cloud seeding — adding particles to clouds to modify precipitation patterns — has been suggested as a way to trigger rain and snowfall, which could help sustain mountain snowpack and water supplies across the western U.S. However, it has been challenging to demonstrate the technique’s effectiveness and efficiency, in part because direct observations of the full chain of events involved in cloud seeding have been lacking.

Ice (Re)Cap: January 2018

Thu, 14 Dec 2017 18:14:45 -0500

Using data from the Dumont d'Urville research station on the coast of East Antarctica, researchers determined that dry katabatic winds over Antarctica substantially decrease the amount of snow that reaches the continent's icy surface. Credit: Environmental Remote Sensing Laboratory, Swiss Federal Institute of Technology (LTE/EPFL).

From Antarctica to the Arctic; from polar caps, permafrost and glaciers to ocean-rafted sea ice; and from burly bears to cold-loving microbes, fascinating science is found in every nook and crevasse of Earth’s cryosphere, and new findings are announced often. Here are a few of the latest updates.

Irrigation drives rain away in East Africa

Thu, 07 Jan 2016 11:31:33 -0500

Croplands in the Gezira Scheme in Sudan, near the confluence of the Blue Nile and White Nile, are watered by a vast network of irrigation canals. Credit: NASA.

Researchers have found that large-scale agricultural irrigation, intended to supplement precipitation, may actually drive rainfall away, potentially exacerbating conditions in some areas while improving them in nonirrigated lands.

Deforestation hangs climate out to dry

Tue, 16 Jun 2015 13:46:00 -0400

Between 1975 and 2001, the Rondônia region of Brazil lost 15,000 square kilometers of tropical rainforest. Credit: NASA/Goddard Space Flight Center.

Across the tropics, vast swaths of forest have been cleared to make room for crops and livestock. Beyond releasing vast stores of carbon trapped in soil and biomass, tropical deforestation has the potential to alter hydrological cycles in ways that could affect temperature and precipitation patterns around the planet, according to a new report in Nature Climate Change.

Sahara dust brings rain and snow to California

Thu, 28 Feb 2013 19:10:41 -0500

Researchers flying over the Sierra Nevada during winter storms in 2009, 2010 and 2011 collected data on the chemical composition of particles suspended in the air from a plane and on the ground, and then combined those data with cloud and particle data from satellites. Courtesy of Kimberly Prather

Ready for takeoff. Scientists flew through storms to measure aerosols to determine if and how aerosols affect winter precipitation in California. Courtesy of Kimberly Prather

One of the field sites in the Sierra Nevadas where researchers sampled winter precipitation. Courtesy of Kimberly Prather

What triggers the mountain rain and snow that are vital to California’s water and energy needs? The answer, according to new research, is blowing in the wind: dust and bacteria from as far away as Africa’s Sahara Desert.

AGU: Colorado ski industry owes Great Salt Lake thank you note

Thu, 05 Jan 2012 06:41:58 -0500

Utah's Great Salt Lake, as seen from the International Space Station in August 2003. The north and south sections of the lake are separated by a railway and have different salt concentrations. NASA Earth Observatory

SAN FRANCISCO — Colorado skiers have long suspected that snowfall is fluffiest when winds blow salt and dust eastward from the Great Salt Lake in Utah. Now that wisdom is confirmed by science.