- Rozovsky wins prestigious NSF Early Career Award
- UD students meet alumni, experience 'closing bell' at NYSE
- Newark Police seek assistance in identifying suspects in robbery
- Rivlin says bipartisan budget action, stronger budget rules key to reversing debt
- Stink bugs shouldn't pose problem until late summer
- Gao to honor Placido Domingo in Washington performance
- Adopt-A-Highway project keeps Lewes road clean
- WVUD's Radiothon fundraiser runs April 1-10
- W.D. Snodgrass Symposium to honor Pulitzer winner
- New guide helps cancer patients manage symptoms
- UD in the News, March 25, 2011
- For the Record, March 25, 2011
- Public opinion expert discusses world views of U.S. in Global Agenda series
- Congressional delegation, dean laud Center for Community Research and Service program
- Center for Political Communication sets symposium on politics, entertainment
- Students work to raise funds, awareness of domestic violence
- Equestrian team wins regional championship in Western riding
- Markell, Harker stress importance of agriculture to Delaware's economy
- Carol A. Ammon MBA Case Competition winners announced
- Prof presents blood-clotting studies at Gordon Research Conference
- Sexual Assault Awareness Month events, programs announced
- Stay connected with Sea Grant, CEOE e-newsletter
- A message to UD regarding the tragedy in Japan
- More News >>
- March 31-May 14: REP stages Neil Simon's 'The Good Doctor'
- April 2: Newark plans annual 'wine and dine'
- April 5: Expert perspective on U.S. health care
- April 5: Comedian Ace Guillen to visit Scrounge
- April 6, May 4: School of Nursing sponsors research lecture series
- April 6-May 4: Confucius Institute presents Chinese Film Series on Wednesdays
- April 6: IPCC's Pachauri to discuss sustainable development in DENIN Dialogue Series
- April 7: 'WVUDstock' radiothon concert announced
- April 8: English Language Institute presents 'Arts in Translation'
- April 9: Green and Healthy Living Expo planned at The Bob
- April 9: Center for Political Communication to host Onion editor
- April 10: Alumni Easter Egg-stravaganza planned
- April 11: CDS session to focus on visual assistive technologies
- April 12: T.J. Stiles to speak at UDLA annual dinner
- April 15, 16: Annual UD push lawnmower tune-up scheduled
- April 15, 16: Master Players series presents iMusic 4, China Magpie
- April 15, 16: Delaware Symphony, UD chorus to perform Mahler work
- April 18: Former NFL Coach Bill Cowher featured in UD Speaks
- April 21-24: Sesame Street Live brings Elmo and friends to The Bob
- April 30: Save the date for Ag Day 2011 at UD
- April 30: Symposium to consider 'Frontiers at the Chemistry-Biology Interface'
- April 30-May 1: Relay for Life set at Delaware Field House
- May 4: Delaware Membrane Protein Symposium announced
- May 5: Northwestern University's Leon Keer to deliver Kerr lecture
- May 7: Women's volleyball team to host second annual Spring Fling
- Through May 3: SPPA announces speakers for 10th annual lecture series
- Through May 4: Global Agenda sees U.S. through others' eyes; World Bank president to speak
- Through May 4: 'Research on Race, Ethnicity, Culture' topic of series
- Through May 9: Black American Studies announces lecture series
- Through May 11: 'Challenges in Jewish Culture' lecture series announced
- Through May 11: Area Studies research featured in speaker series
- Through June 5: 'Andy Warhol: Behind the Camera' on view in Old College Gallery
- Through July 15: 'Bodyscapes' on view at Mechanical Hall Gallery
- More What's Happening >>
- UD calendar >>
- Middle States evaluation team on campus April 5
- Phipps named HR Liaison of the Quarter
- Senior wins iPad for participating in assessment study
- April 19: Procurement Services schedules information sessions
- UD Bookstore announces spring break hours
- HealthyU Wellness Program encourages employees to 'Step into Spring'
- April 8-29: Faculty roundtable series considers student engagement
- GRE is changing; learn more at April 15 info session
- April 30: UD Evening with Blue Rocks set for employees
- Morris Library to be open 24/7 during final exams
- More Campus FYI >>
8:51 a.m., Jan. 19, 2011----Delaware got another taste of winter last week, with a storm system that delivered several inches of the white stuff to the northern part of the state.
Had enough of Old Man Winter? Fearful we're in for a repeat of the Snowmaggedeon of a winter we had last year? Can't believe spring is still nine long weeks away?
Cheer up and look on the bright side. There are a slew of environmental benefits to be had from a good snowfall, according to David Hansen, a University of Delaware Cooperative Extension soil and environmental quality scientist.
The phrase “blanket of snow” is more than a visual description -- it's also accurate in terms of warmth, says Hansen. Freshly fallen, un-compacted snow is typically 90 to 95 percent trapped air. Because the air can barely move, heat transfer is greatly reduced, thus slowing the flow of heat from the warm ground to the cold air above.
This blanket effect makes snow an excellent insulator for gardens and landscapes, protecting these natural areas and their animal inhabitants against frigid temperatures and damaging winds.
Snow also lessens -- to some extent -- the extremes of temperature fluctuation to which the soil is subjected, says Hansen. This can be critical for some plants, including evergreens. Even in mid-winter, if air temperature within the canopy of these plants rises during the day, the plants will try to take moisture from the soil. If the soil is frozen, the plants can actually die of thirst.
The extent to which snow insulates depends on its depth. Generally, temperatures underneath a layer of snow increase about 2 degrees Fahrenheit for each inch of accumulation. Because the soil also gives off some heat, the temperature at the soil surface can be much warmer than the air temperature. Hansen says that a study done at minus 14 degrees Fahrenheit found that the soil below a 9-inch deep snow registered a surface temperature of 28 degrees.
Melting snow provides needed moisture to many plants. Even dormant plants continue to lose moisture as water evaporates through their branches. Evergreens, which keep their foliage throughout the winter, are at even greater risk of injury from lack of moisture.
Snow also replenishes the water supply. You may have heard that 10 inches of snow equals 1 inch of rain, but it's actually much more complex than that, according to Hansen. This ratio only works well when temperatures hover around freezing.
At higher temperatures, say a few degrees above freezing, snow is often heavy and laden with water. Then, the ratio may be more like 5 to 1 -- 5 inches of snow will melt into 1 inch of water, says Hansen. At lower temperatures, the snow tends to be light and fluffy and the ratio can be as high as 15 to 1.
How well the snow replenishes the water supply all depends on how it melts, notes Hansen. A fast melt can cause flooding, especially in urban areas. Rapid melting combined with clogged drain systems can send polluted runoff directly into streams and rivers. But a slow snow melt means water trickles slowly into the earth, percolating through the soil and refilling our aquifers, providing water for our drinking supply.
If Mother Nature continues to bestow us with snowstorms in the weeks ahead, try to remember that those flakes are protecting your plants, your water supply and Delaware's wildlife.
Article by Margo McDonough
Photo by Danielle Quigley