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SNOTEL Snowpack Recording Stations

Manual Snow Measurement
Cover image from
Snow surveying by James C. Marr
USDA 1940 Publication 380
Public Domain
Courtesy UVA, Google & HathiTrust

For a modern view visit
https://www.meted.ucar.edu/afwa
/avalanche/print.htm

Removing snow surveying apparatus
from canvas carrying case
preparatory to use
From
Snow surveying by James C. Marr
USDA 1940 Publication 380
Public Domain
Courtesy UVA, Google & HathiTrust

Water is a precious resource throughout the world. Most of Utah consists of arid habitats and many users clamor for their share of the scarce moisture. Ever-growing demand challenges water managers to insure that agriculture, cities and nature all get their portion. Predicting and monitoring stream flow is imperative in order to know how much to hold in reservoirs or send downstream, and when to anticipate floods, enact water conservation measures, and in general provide for all users.

Much of Utah’s water originates in the mountain snowpack. Early in the twentieth century, the Department of Agriculture constructed a series of Snow Courses in mountainous areas of the West. Hardy personnel periodically trekked in to measure snow depth with a long ruled stick. Water content was found by taking a core sample, weighing it and subtracting out the weight of the metal tube. Stream gauging stations installed by the US Geological Survey allowed correlation of stream flows with snowpack measures.

In the 1970’s, monitoring snow courses became more automated. The reporting stations were named “SNOTEL” for snowpack telemetry. Now there are over 600 SNOTEL sites in 13 western states. The measurement functions of SNOTEL stations are elegantly simple and reliable. Air and soil temperatures are monitored with standard thermocouples. Water content of the snowpack is measured by its weight atop a broad thin bladder called a snow pillow that is filled with antifreeze. The snow pillow is carefully spread on the ground. Accumulating snow presses down on the pillow, pushing some antifreeze out a connecting tube to a pressure sensor.

Some SNOTEL sites also measure snow depth, using the autofocus technology of the digital camera. Subject distance is gauged by the time delay of an ultrasonic pulse, like sonar or hearing your voice echo back in a canyon. At a SNOTEL station, a similar sensor is placed high above the expected snow line. As snow accumulates, the downward facing sensor reports the shortening distance between it and the snow surface.

SNOTEL stations have batteries and a solar panel to power their hourly data transmissions. Ogden has one of the two master receiving stations. Want to size up mountain snowfall from the last storm or know how warmly to dress for an outing? Just go to Utah’s SNOTEL information site on the web.

Credits:

Image: Public Domain, Courtesy University of Virginia, Google and HathiTrust, Cover image from Snow surveying by James C. Marr, USDA 1940 Publication 380
Theme Music: Written by Don Anderson and performed by Leaping Lulu from their CD “High Road, Low Road”
Text: Jim Cane & Linda Kervin, Bridgerland Audubon Society https://www.bridgerlandaudubon.org
Voice: Linda Kervin, Bridgerland Audubon Society https://www.bridgerlandaudubon.org
Additional Reading:

Water Conservation Begins with Snow Surveys, USDA NRCS, https://www.wcc.nrcs.usda.gov/factpub/wc_ss.html

Snow Hydrology: SNOTEL, Randall Julander, Civil & Environmental Engineering, University of Utah, (formerly at https://www.civil.utah.edu/~cv5450/snotel/snotel.htm)

Utah Snow Survey Program, USDA NRCS, https://www.ut.nrcs.usda.gov/snow/

NRCS Snow Surveyor Collects Vital Water Data, Lives Dream Job, Spencer Miller, NRCS, Jan 10, 2013, https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/home/?cid=STELPRDB1076993

Snow Surveys and Water Supply Forecasting, National Atlas of the United States, US Department of the Interior, formerly at https://www.wcc.nrcs.usda.gov/factpub/sect_4a.html

Utah Snow Survey Program, Natural Resources Conservation Service, US Department of the Interior, https://www.nrcs.usda.gov/utah/snow-survey

Map, Utah USGS SNOTEL Stations https://www.wcc.nrcs.usda.gov/snotel/Utah/utah.html

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Desert Tortoises

Click for a larger view of an adult Desert Tortoise. Courtesy & Copyright 2009 Kevin Durso, Photographer
Adult Desert Tortoise
Gopherus agassizii
Courtesy & Copyright 2009
Kevin Durso, Photographer

Click for a larger view of an adult Desert Tortoise. Courtesy & Copyright 2009 Kevin Durso, PhotographerAdult Desert Tortoise
Gopherus agassizii
Courtesy & Copyright 2009
Kevin Durso, Photographer

Click for a larger view of an adult and juvenile Desert Tortoise. Courtesy & Copyright 2009 Andres Durso, PhotographerAdult & Juvenile Desert Tortoise
Gopherus agassizii
Courtesy & Copyright 2009
Andrew Durso, Photographer

Click for a larger view of a juvenile Desert Tortoise. Courtesy & Copyright 2009 Andres Durso, PhotographerJuvenile Desert Tortoise
Gopherus agassizii
Courtesy & Copyright 2009
Andrew Durso, Photographer

Tortoises are turtles that live their whole lives on land. Most tortoises are native to Africa and South America, but several are North American including the Desert Tortoise whose range extends to southwestern Utah. Their shells consist of enlarged scales called scutes. These scutes are tan, black, or dull orange, and etched with many concentric lines, like the growth rings of a tree. Desert Tortoises look like grizzled old men, even the Oreo-sized hatchlings, which over several decades will grow to football size.

Desert Tortoises mate in the spring, and a few months later, the female lays her 5 or 6 eggs in a funnel-shaped pit dug in the sand. The sex of the baby Desert Tortoises is determined by the sun’s heating rather than by genetics – cooler incubation yields males, hotter eggs produce females, with a mix of sexes developing at intermediate temperatures.

Desert Tortoises primarily eat the flowers of desert plants such as globemallow and threeawn. Because most desert plants only bloom briefly each spring, tortoises must eat a lot between April and June, although they can be active during all but the coldest months. Being toothless, they grind up their vegetarian fare using a specialized bone embedded in their jaw muscles. Like cows and other herbivores, they depend on microbes in their gut to digest the cellulose in their diet. Even more than food, water is precious to a Desert Tortoise. They have little to spare, sometimes going for months without urinating, but will pee defensively if handled. Resist the temptation to pick them up or you will rob the poor animal of its water supply for the entire year.

Once found throughout the Mojave and Sonoran deserts, Desert Tortoises are much less common than they were a century ago. They have not fared well with urbanization, highways, and off-road vehicle traffic. An upper respiratory tract disease can also be lethal, especially when crowded or stressed, as in captivity. Desert Tortoises are now protected by the US Endangered Species Act.

Today’s program was written by Andrew Durso of USU’s biology department.

Credits:

Theme: Courtesy & Copyright Don Anderson Leaping Lulu
Images: Courtesy & Copyright Andrew Durso and Kevin Durso
Text: Andrew Durso, https://www.biology.usu.edu/htm/our-people/graduate-students?memberID=6753

Additional Reading:

Gopherus agassizii, Turtle Conservancy, https://www.turtleconservancy.org/news/tag/Gopherus+agassizii

Grover, Mark C., DeFalco, Lesley A, Desert Tortoise(Gopherus agassizii): Status-of-Knowledge, Outline With References, USDA, 1995, https://www.fs.usda.gov/research/treesearch/30627

Desert Tortoise, Gopherus agassizii, Mojave National Preserve, https://www.mojavenp.org/Gopherus_agassizii.htm

Gopherus agassizii (COOPER, 1861), The Reptile Database, Peter Uetz and Jakob Hallermann, Zoological Museum Hamburg,
https://reptile-database.reptarium.cz/species?genus=Gopherus&species=agassizii

Desert Tortoise, Species, Utah Division of Wildlife Resources, Utah Department of Natural Resources, https://fieldguide.wildlife.utah.gov/?species=gopherus%20agassizii

Desert Tortoise Information and Collaboration, Mojave Desert Ecosystem Program, https://www.mojavedata.gov/deserttortoise_gov/index.html

Red Cliffs Desert Reserve, http://www.redcliffsdesertreserve.com

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Tracking Wildlife in Winter

Jumping Mouse Tracks
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Moose Tracks in Snow
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Cottontail Rabbit Browse & Scat
Photo Courtesy & Copyright 2011
Mark Larese-Casanova

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

The cold depth of winter is a time when many animals are hiding- either hibernating until the thaw of spring, or finding shelter and warmth in burrows, under logs, or in the tangled branches of evergreen trees.

However, snow falls in much of Utah, and even a dusting can reveal the stories of wildlife in winter. It’s a bit like solving a mystery. By reading the clues of animal tracks, we can know not only the type of animal that made them, but also where they were going and what they were doing.

The most obvious clue is the size of a track. Smaller animals make smaller tracks, and also sets of tracks that are generally closer together.

The shape of an animal track is also very revealing. Members of the canine family, including domestic dogs, coyotes, and fox, show four toes in front, each with a visible claw. Felines, including bobcats and mountain lions, also show four toes, but no claws. Tracks from members of the weasel family, such as mink, ermine, and skunks, show five toes, each with a claw. Raccoon, squirrel, and mouse tracks almost look like they were made by tiny human hands. The long tails of some animals, including deer mice, jumping mice, and weasels, often leave a characteristic line through the center of a set of tracks.

Combining the size and shape of tracks reveals further details about wildlife. The three inch long cloven hoof print of a mule deer is easily recognizable. An elk track looks almost identical, but is about four inches long. A similar moose track is even larger at six inches long.

Figuring out which animal made a track is only half of the story. If we follow tracks, we’ll surely find clues about an animal’s daily life. Wildlife often gather around sources of water that aren’t frozen, which are critical to winter survival. Perhaps rabbit tracks lead under a spruce tree where browsed branches and droppings indicate a frequent feeding spot. Maybe mouse tracks lead from tree to rock to log as it avoids owls and hawks.

While we are much more likely to see wildlife during the warmer months, winter gives us a chance to unravel the story of daily survival during the most difficult time of the year in Utah.

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:
Images: Courtesy and Copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova

Additional Reading:

Canadian Wildlife Federation: Tracking Down Winter Wildlife. https://www.cwf-fcf.org/en/action/how-to/outside/tracking-down-winter-wildlife.html

Murie, O. J. (1982). Animal Tracks. Peterson Field Guides. New York, NY: Houghton Mifflin. https://www.amazon.com/Peterson-Field-Guide-Animal-Tracks/dp/061851743X

Vermont Nature and Outdoors: Tracking Winter Wildlife. https://www.ruralvermont.com/vermontweathervane/issues/winter/97012/vins97012_tracking.shtml

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Baby, It’s Cold Outside

Baby, It’s Cold Outside: Peter Sinks. Courtesy the Utah Climate Center

Peter Sinks
Courtesy Utah Climate Center

Peter Sinks
Campbell Scientific Weather Station

Courtesy Utah Climate Center

Holly: Hi, I’m Holly Strand.

-18 in Logan, -20 in Moab, -26 degrees in Randolph. In other words, it’s January in Utah! Subzero temps are common this time of year across most of the state.

Some sources give – 50 degrees Fahrenheit as the coldest temperature ever recorded in Utah. It was -50 on Feb 6, 1899 in Woodruff and again on Jan 5, 1913 at the East Portal of Strawberry Reservoir. But—as many of you know—the real lowest temperature recorded was -69 degrees occurring at Peter Sinks on Feb 1, 1985. There were two weather stations recording at the time. A Campbell Scientific instrument recorded a temperature of -70.5 from a sensor 20 inches above the snow surface. A few days later, USU student Zane Stephens retrieved a minimum recording alcohol thermometer which registered -68.3. The National Bureau of Standards calibrated Stephens’ thermometer which adjusted the reading to -69.3. This became the ‘official’ temperature minimum since– at that time–the National Weather Service only recognized the type of weather station used by Stephens.

While the -69 observation was verified, the station it came from was not part of any long-term weather monitoring network. That’s why you still see the -50 cited as the low. But -69 is so much better. For this figure gives Utah boasting rights for having the 2nd coldest recorded temperature in the lower 48 (plus Hawaii). -69 beats the coldest temperature recorded in Europe which is only -67. And it comes fairly close to North America’s record which is -81 in the Canadian Yukon. Just so you know, Asia’s record is -90 in Verkhoyansk in Siberia. And of course, Antarctica takes the cake with -129 at Vostok Research Station.

But back to Utah. Peter Sinks—where the -69 reading occurred–is an oval-shaped limestone sinkhole located on the crest of the Bear River Range just west of Old Limber Pine off of Highway 89. It’s about 150 meters deep and 1 km long. Having no tributary valleys, it’s a perfectly closed basin. On clear nights the area surrounding the sink radiates away its heat. And if the wind is calm, the, colder heavier air sinks and pools on the basin floor . If there were an outlet the cold air could flow out and warmer air could lower in to replace the outgoing cold. But there isn’t an outlet.

You probably recognize this situation—it’s an inversion. The Wasatch Front valleys and Cache Valley experience this same phenomenon during winter. Snow cover reflects incoming sunlight which cools the land surface and warm temperatures aloft seal the colder air down below. Meanwhile, a high pressure system called the Great Basin High brings clear, still air which locks the inversion in place. But the large size of these populated valleys prevents the temperature from dropping down to -69. Thank goodness. But in our case, manmade pollutants created during the inversions create a toxic cold air cocktail that we have to endure. At least until a low pressure system comes in and blows the lid off the inversion, pulling the cold air upward and “mixing” it away.

For more information on inversions and to see pictures of the notorious Peter Sinks, visit www.wildaboututah.org

Thanks to Robert Davies of the Utah Climate Center at Utah State University for his help in developing this episode.

For Wild About Utah, I’m Holly Strand.

Credits:

Image: Courtesy Utah Climate Center
Text: Holly Strand

Sources & Additional Reading:

Ahrens, C. Donald, Perry Samson. Extreme weather and climate. Belmont, CA : Brooks/Cole, Cengage Learning.

Clements, Craig B. Whiteman, C. David Horel, John D. 2003. Cold-Air-Pool Structure and Evolution in a Mountain Basin: Peter Sinks, Utah. Journal of Applied Meteorology, Jun 01, 2003; Vol. 42, No. 6, p. 752-768

Moller, Allen; Robert R. Gillies. 2008 Utah Climate. Logan, Utah: Utah Climate Center, Utah State University

NOAA, State Climate Exchange Committee. State Temperature Extremes https://www.ncdc.noaa.gov/extremes/scec/records

Utah Climate Center, Utah State University https://climate.usu.edu/

Utah Climate Center with support from Campbell Scientific, Inc. Peter Sinks Monitoring Project. Site history, data and more pictures. https://twdef.usu.edu/Peter_Sinks/Sinks.html

Utah.Gov Choose Clean Air https://www.cleanair.utah.gov/