Micrometeorology Textbook

first_imgSome landscapes — like forests — are known for keeping carbon dioxide out of the atmosphere. Others shed carbon dioxide or other gasses that can affect the environment. Calculating just how much of each gas is held or released can be difficult but University of Georgia scientist Monique Leclerc has literally written the book on the subject.Leclerc has pioneered the use of a formula known as eddy covariance or eddy-correlation to measure evapotranspiration, ozone deposition and agricultural impacts — like how much methane cows emit. Leclerc recently released a book on how to use these formulas most effectively.Teaches how to interpret dataCo-authored by Thomas Foken, Leclerc’s book, Footprints in Micrometeorology and Ecology, is the first textbook on the subject and covers how to interpret meteorological measurements made at a given level over a surface with regard to characteristic properties such as roughness, albedo, heat, moisture, carbon dioxide and other gases. “Every year, thousands and thousands of scientists across the world use the eddy covariance method to measure how many pesticides are released from a field, how much water is lost from irrigation to the air and how much CO2, nitro oxide and methane are released by cattle, over applications of animal waste and over rice patties,” said Leclerc, a UGA Regents Professor with the UGA College of Agricultural and Environmental Sciences. The textbook includes chapters for professionals in various fields, including agriculture. “Farmers want to know the true nitrous oxide emissions emitted from fertilizer applications, or their methane losses from manure piles or the optimum amount of irrigated water needed to water their crop given a set of environmental conditions in a particular year,” she said. Practical uses for farmersBut how can farmers use this data?“They can determine how much methane their cows are emitting and adjust their diets to change that amount. They can also determine whether gases are coming from their cows or another farmer’s cows,” Leclerc said.For her research at UGA, Leclerc has field studies across the state, the nation and the world. In Georgia, she has sites on the UGA campus in Griffin, in Plains, Ft. Valley and at the UGA Marine Institute on Sapelo Island. “We take measurements every where from peach orchards in Hollonville to the salt marshes near the Georgia coast,” she said.The National Science Foundation Long-Term Ecological Research project paired Leclerc with the UGA Marine Institute. This project focuses on sea levels and how they related to carbon balance. Continual measurementsShe and her team take measurements of gases, like carbon dioxide, heat, evaporation and energy, “continuously 24 hours a day, 7 days a week, 10 measurements per second,” she said. “In the same spot, we also collect wind data at the same very high rate. Then we take all that data to the lab and analyze it to come up with a footprint analysis given the vegetation type, mean windspeed, sky conditions and other related variables. Our job in this project is to determine how much carbon is taken up by the vegetation.”Leclerc explains that rivers carry carbon into oceans and plants remove CO2 from the atmosphere. “Aquatic plants are in and under the water when the tide is high and then they come out of the water. There are a lot of changes over a 24-hour period. Our job is to determine how much carbon is taken up,” she said.Leclerc has also worked with the U.S. Department of Energy at the Savannah River National Laboratory near Akins, S.C. There she took measurements over corn fields and peanut fields, and broken mixed forests. A world-renowned expert in the field of agricultural and forest meteorology, Leclerc serves on several advisory panels to the international scientific community. She wrote the newly published book after being approached by researchers like McGill University scientist Peter Schuepp who needed help interpret aircraft data taken over an island in Lake Superior.Using isn’t the same as understanding“Scientists have switched to this measurement method and they use it, but they always ask me if they are getting a true measurement of the atmosphere over the field or over the neighbor’s house. And, if the plants had drought or insect damage, we know right away,” she said. Leclerc says instruments record differently on cloudy day than on stormy or sunny days. And respiration measurements over forests are different than measurements over wheat fields. “It’s important to know how much gas is going up from the surface, soil and plants and coming down from the atmosphere,” she said.In the textbook, Leclerc and Foken provide scientists with guidelines for how to interpret the eddy-covariance data. “We also included theories to empower people so they can use the methods in the book on their own,” she said. “There are weaknesses and strengths of this method and we are very candid with our advice.”Leclerc equates environmental meteorology work to a puzzle. “In the puzzle you have many pieces. I am just one piece, but my piece is the missing link,” she said. Footprints in Micrometeorology and Ecology book can be ordered at http://link.springer.com/.last_img read more

SUP the TUCK: Day 4

first_imgJune 26, 2018, day 4/7 A Cherokee Legend: After traversing the wide Yosemite-like origins of the East Fork it is easy to understand the physics of flooding; a broad granite escarpment as far as the eye can see acting like a stone plate funnelling rain water to a river as wide as a two-lane country road. This  river has had its share of tragedies. On December 30, 1882 the ‘most awful’ public works of the state occurred. Nineteen convicts, part of a chain gang, drowned while crossing the river. They were buried in a mass grave with no marker to honor the site, though it is believed to be near the Cowee Tunnel. Even today the tunnel’s ceiling continues to drip, some say it’s the tears of the convicts. In 1840 there was a record high ‘May Fresh’ flood which occurred as settlers were beginning to arrive. In 1940 “the great deluge” occurred. Houses, barns, animals and people were swept away including every bridge that crossed the river. Towns and families were left isolated, leaving some to send messages across the river with bows and arrows. The dams were built soon after providing a level of protection to downstream communities as well as electricity and controlled releases for boaters and fisherman. Still on the East Fork of the Tuckasegee we were now below the last dam-controlled section. Finally, I told John, we will be paddling on a  conventional river trip rather than traversing bone-crunching drops, portages and man-made lakes. We stuffed wet gear into waterproof bags and secured it on our paddleboards. The next  2 miles were class 1-2 whitewater down to the little town of Tuckasegee where the West Fork joins. The Tuckasegee River now flows unrestricted 60 miles to the Little Tennessee River at Lake Fontana. Have you ever slept below a dam? My first experience was below the Fontana Dam. All night there was a pulsing green glow and hum, a UFO-like reminder that I was not at home in my bed. John Sherman and I awoke below the Cedar Cliff Lake to the eerie sound of a  dam spewing water out of a concrete hole and a huge generator spinning electricity. John emerged out of his green hammock-tent like a molting stonefly. Blank and expressionless he muttered  “I hate being wet”. We awoke to mud, mist and river. The crack of lightning and the tsunami rain from the portage last night jarred and drenched our spirits into a sleepless night. We started a fire. John noticed a leak in his paddleboard and his attempt to repair it was unsuccessful. I  called my wife Jana who kindly drove from Asheville to pick up John and his useless paddleboard.  While home, he noticed his left ring finger was turning blue from his injury hiking Bonas Defeat. He went to the emergency room and had his ring cut off saving his finger. While all this drama played out I paddled downstream a few miles into Cullowhee, near the Western Carolina University and camped on a sandbar in the middle of the river. My “solo” night included a bonfire on the beach, late night swim and fresh trout for breakfast. Click here to read Day 3 Moving much quicker now we made good time to East Laporte River Park in Cullowhee and stopped to dry out our gear. Wet sleeping bags, clothes and food were laid it out in the sun to dry. I took John through the experience of gutting and filleting his first trout with a ceremonial flare.  The  tasty fish was washed down with a local IPA from the gas station across the street. Part 2: The Tailwaters The last three days were brutal, orienteering with paddleboards down one of the most dramatic river basins in the world. The hidden grandeur of the Tuckasegee River is the headwaters of the East Fork. We paid a price. Sore and fatigued, wet and discouraged by rain, John now with a swollen finger;  I was beginning to question the wisdom of our trip. We are both “solo adventurers”, self-proclaimed tough guys that prefer going it alone. We quietly ate our breakfast, John prefering to cook non-Mountain House freeze dried breakfast on his own cook stove. I looked irritably back and forth between Johns fluorescent tent hanging 3 feet off the mud and my brown tarp  slung over my paddleboard sitting directly in it. Uktena was a serpent as large around as a tree trunk, with antlers on its head, a blazing crest on its forehead and scales glowing like fire living in the river. Whoever is seen by Uktena is so dazed by the bright light he runs toward the snake instead of trying to escape. There is a location 2 miles above Deep Creek near Bryson City where Uktena struggled and left deep scratches while trying to move upriver. The Cherokee and other Native Americans have a long history with the Tuckasegee river. The name Tuckasegee has various origins…..a popular consensus is an anglicization of the word Tsiksitsi meaning “crawling terrapin” due to the rivers sluggish waters. Evidence of fishing weirs (V-shaped rock funnels) are still evident. The first one encountered was just before the Shook Cove public access area. The water is shallow and slid over pebbles and sand sluicing us downstream into the apex of the weir. Our Badfish paddleboards are designed for fishing allowing for heavy  gear and fishing poles to be secured and still navigate  rapids. We pulled into an eddy to photograph and fish. Soon the sun broke out, drying us and reviving our spirits. Stay tuned all this week to read about the rest of their river journey!last_img read more