WEEK 33: UTAH
Utah and the Arctic: From One Desert to Another
By Tyler King, Ph. D. candidate at Utah State University and Dr. Bethany Neilson, Associate Professor of Civil and Environmental Engineering at Utah State University.
When compared with the hot, dusty, desiccated desert landscapes of Utah, the cool, waterlogged, lush tundra landscapes of northern Alaska hardly seem like a desert. However, with less than 250 millimeters (10 inches) of precipitation a year, both of these landscapes meet the World Meteorological Organization’s definition of desert landscapes.
These seemingly opposite landscapes arise from the all-important environmental variable — temperature. While annual precipitation is a reasonable way to classify deserts, a more accurate measure is the aridity — or dryness — of a landscape, which is in part driven by temperature. High relative humidity in the atmosphere of northern Alaska allows the region to retain soil moisture and develop lush tundra vegetation. In addition, cold annual temperatures leads to extensive permafrost — or permanently frozen ground — which acts as an impermeable barrier to keep water near the ground surface producing a very wet desert landscape seen in the tundra of northern Alaska.
The tundra landscape of northern Alaska is part of the Arctic Polar Desert — the world’s second largest desert that covers an area nearly twice as large as the entire continental U.S. and includes parts of Alaska (the northernmost U.S. state), Canada, Greenland (part of the Kingdom of Denmark), Iceland, Norway, Sweden, Finland, and Russia. As the term “Arctic” implies, this region is located in the far north, near the North Pole.
Temperature is arguably one of the most significant factors in nearly all environmental processes. It controls how fast biological and chemical processes occur, it dictates how much water vapor can be held in air, how much oxygen can be held in water, and even influences the physical form that elements take in our natural environment.
In rivers all over the world, water temperature is of paramount importance. This is especially important in the Arctic where during most of the year, everything is frozen leaving only a few months of a warm season for aquatic plants to grow, aquatic insects to complete their life cycles, and fish to migrate, spawn, forage, and return to overwintering lakes. On top of this, during the warm season the rivers run and landscape drains and a tremendous amount of dissolved carbon is released from thawing carbon rich soils and transported through Arctic lakes, streams, and rivers. Where this carbon ends up is in part dictated by the temperature of the water in which it is transported. And there is plenty of carbon in the Arctic: it is estimated that frozen Arctic soils contain twice the amount of carbon that is currently in circulation in our atmosphere. While these carbon sources and processes may be occurring far away from most human activity, their impacts are by no means isolated to the Arctic. Wind currents circulate carbon dioxide released from thawing tundra broadly, giving global significance to the carbon released to the atmosphere in the Arctic.
While the importance of Arctic river temperature is acknowledged, it remains at the frontier of scientific discovery. And some of the country’s most cutting-edge research on this is happening in Utah.
From our home institution of Utah State University here in Logan, Utah, we have studied river temperature dynamics in Utah, Texas, Nevada, Washington, Sweden, Switzerland, Norway, Australia, and the far northern reaches of Alaska. Data from such a wide variety of sources allows us to compare and contrast systems from around the world. One of our key projects is focused on coupling computer models with data collected from the North Slope of the Brooks Range in Alaska so we can piece together the puzzle of what controls arctic river temperature and how these may change in the future.
Studying river temperature and gathering sufficient data means a lot of time spent in the field. Each summer we leave Utah and head to Alaska where our work involves maintaining several hundred sensors, routine physical and chemical measurements, and periodic aerial surveys via helicopter throughout the Kuparuk River watershed in northern Alaska. We are stationed at the Toolik Field Station — an Arctic scientific field station run by the University of Alaska Fairbanks — to complete our work. Living and working at this interdisciplinary science establishment provides opportunities to collaborate with researchers in a variety of distinct yet connected disciplines. Our research efforts are supported by the National Science Foundation, Utah State University, and the University of Alaska Fairbanks.
With each summer we spend in Alaska, we are able to add one more piece to the puzzle of what controls river temperatures in the Arctic. So far we have found that Arctic river temperatures are colder than expected, and we suspect that this is in part due to a strong connection between rivers and the underlying permafrost or frozen ground. Movement of water through the ground allows energy to be transferred from the river to the underlying permafrost and prevents rivers from becoming too hot for many aquatic species. As a result, the fate of permafrost, which has been warming over the last decades, and river temperature are likely intimately entwined.
Our findings will help us better understand how Arctic climate change will impact arctic rivers, and provide the data needed to better inform climate driven policy decisions. While our work indicates that river temperatures will be different in the future, how different depends to some degree on what humans at lower latitudes decide to do in the face of climate change. If carbon emissions continue at the current pace, air temperatures will continue to rise at northern latitudes much faster than in the rest of the globe, resulting in impacts to ecological and human health — not only for residents of the Arctic, but in Utah as well. The actions of humans in Utah (and the rest of the world) impact the Arctic. These impacts are amplified in the Arctic and then returned to Utah and results in increases in air temperature, decreases in Utah’s legendary snowpack, and lengthening of the wildfire season. And this is what connects the residents of our warm desert region here in Utah with the processes and fate of another colder, desert region: the Arctic.
About the Authors:
Dr. Bethany Neilson is an Associate Professor of Civil and Environmental Engineering at Utah State University. She has researched river temperature dynamics around the globe and has been conducting research in Arctic Alaska since 2009. Along with her own research projects, Dr. Neilson is an associated scientist with the Arctic Long Term Ecological Research Station at Toolik Lake.
Tyler King is a PhD student at Utah State University. Tyler got his start in Alaskan hydrology through an internship at the Alaska Pacific River Forecasting Center in Anchorage, and went on to study the impacts of hydropower production on river temperature at the Norwegian University of Science and Technology before joining Dr. Neilson at Utah State University to research Arctic river temperature.
