Faculty in the Department of Atmospheric Sciences lead world-class scientific research programs that are funded by federal and state agencies at a current level of nearly $4 million annually. Major funding sources include the National Aeronautics and Space Administration (NASA), National Science Foundation (NSF), National Oceanic and Atmospheric Administration (NOAA), National Weather Service (NWS), Department of Energy (DOE), and Bureau of Land Management (BLM). Nearly all of our graduate students are supported by research assistantships, teaching assistantships, or graduate fellowships. Areas of research and graduate study include cloud-climate interactions; mountain weather and climate; global and regional climate; cloud, boundary layer, turbulence and weather modeling; and tropical meteorology.
Direct links to individual research group web pages and faculty home pages are provided below.
- Aerosol-Cloud-Climate Systems Group
- Climate Research Group
- Cloud, Boundary Layer, and Wildfire Modeling Group
- Data Assimilation and Predictability
- Hallar Aerosol Research Team
- Land-Atmosphere Interactions Research Group
- MesoWest Research Group
- Mountain Meteorology Group
Despite significant advances in improving air quality, human society continues to face challenges arising from cross-border transport of pollutants, wildfire emissions, increased exposure by expanding urban populations, and mounting medical evidence pointing to adverse health effects due to exposure to various pollutants. Knowledge of atmospheric science is critical for devising effective policy in order to improve air quality, mitigate exposure, and predict the impacts of climate change on future air quality.
Professor John Lin seeks to understand how emissions from cities, wildfires, and dust events affect the air quality at a particular “receptor” location. He is a founding member of the Utah Atmospheric Trace gas & Air Quality lab (“U-ATAQ”) and combines atmospheric models with observations from a variety of platforms (surface networks, light rail, mobile lab, satellites) to address questions related to air quality. He is also interested in understanding how emissions of air quality-relevant pollutants are linked with emissions of greenhouse gases such as carbon dioxide and methane, in order to devise means of improving air quality while mitigating climate change.
Professor John Horel is leading research on the role of atmospheric vertical structure and transport upon pollutant concentrations along the Wasatch Front and in the Uintah Basin. High concentrations of particulates during winter and ozone during summer along the Wasatch Front and ozone during winter in the Uintah Basin have serious health consequences for the residents of those areas. Data collected from hands-on field campaigns combined with high-resolution modeling of terrain-flow interactions are analyzed to help understand atmospheric controls on pollutant concentrations.
Associate Professor Gannet Hallar's Hallar Aerosol Research Team (HART) uses high quality measurements of aerosol physical and chemical properties, trace gases, and cloud microphysics to understand connections between the atmosphere, biosphere, and climate, along with the impact of anthropogenic emissions on these connections. Via this work, they study the meteorology of air quality, specifically integrating theory and observations of meteorological phenomena on spatial scales ranging from mesoscale to synoptic. HART works closely with the new interdisciplinary cluster focusing on Society, Water, and Climate (SWC) at the University of Utah.
Limited knowledge of the composition and radiative effects of clouds and aerosols is a major contributor to climate prediction uncertainty. Research conducted by Professors Jay Mace, Tim Garrett, and Kevin Perry aims to advance our understanding of cloud and aerosol physics, and improve the parameterization of cloud and aerosol radiative effects in weather and climate models.
Professor Jay Mace is a principal investigator for the Department of Energy’s Atmospheric Radiation Measurement (ARM) program and NASA's CloudSat mission. He uses ground and space-borne remote sensing data combined with aircraft observations to charactierize the properties of clouds to understand the role of clouds within the climate system. This research is conducted in diverse locations ranging from the north slope of Alaska to the tropical western Pacific. He is a lead scientist for two major upcoming field programs funded by ARM: Small Particles in Cirrus (SPartICus), which will examine microphysical processes in cirrus clouds over the ARM Southern Great Plains site in Oklahoma, and the Storm Peak Lab Cloud Property Validation Experiment (StormVEx), which seeks to understand liquid and mixed-phase clouds at a high altitude observatory near Steamboat Springs, CO.
Professor Tim Garrett’s research looks at a broad spectrum of interactions between aerosols, clouds, and climate to improve our understanding and prediction of regional and global climate. His field work involves airborne measurements of clouds and automated imaging of snowflakes in the mountains of the Wasatch range. He is a leader in observational studies and numerical simulations of interactions between Arctic clouds and pollution aerosols of mid-latitude origins. Professor Garrett's recent interests have extended beyond clouds to the development of novel physical models for the economic evolution of global civilization and its carbon dioxide emissions. His current theoretical efforts are directed at providing general thermodynamic representations for the evolution of atmospheric systems.
Professor Kevin Perry concentrates on identifying the sources, sinks, transport, optical effects, and climatic effects of aerosols in the atmosphere. His work has a strong interdisciplinary component, spans many scales, and involves scientists at several institutions. For example, on the global scale, he has shed new light on the intercontinental transport of Asian dust, while at the local scale, he identified the composition of aerosols from the World Trade Center collapse site following the September 11, 2001 terrorist attack.
Mountain Weather and Climate
Research in Mountain Weather and Climate is led by Professors John Horel, Jim Steenburgh, Dave Whiteman, and Sebastian Hoch. Their efforts aim to improve the understanding, analysis, and prediction of atmospheric phenomena over complex terrain, with an emphasis on the western United States. A centerpiece for mountain weather and climate research and instruction is the MesoWest cooperative networks, which integrates observations collected by more than 150 networks and 3000 surface stations in the western United States. Developed by Professor John Horel, MesoWest has revolutionized the analysis of Intermountain weather for atmospheric research and operational forecasting. Professor Horel uses MesoWest data for his research in atmospheric data assimilation and forecast verification over complex terrain, as well as his many phenomenological studies of mountain weather including investigations of circulations induced by the Great Salt Lake.
Professor Jim Steenburgh’s research interests lie primarily in issues relate to the weather and climate of the Intermountain West and adjoining regions. He served as co-lead scientist for the Intermountain Precipitation Experiment (IPEX), a field and research program examining orographic precipitation processes over the Wasatch Mountains, and has led an ongoing effort to better understand lake-effect snowstorms produced by the Great Salt Lake. More recently, his group has examined how topographic and boundary layer processes modify the evolution of cyclones, fronts, and precipitation systems over the Intermountain West.
Professor Dave Whiteman is a leader in the study of thermally driven flows, boundary layer processes, and cold pools, and is author of “Mountain Meteorology”, one of the few textbooks concentrating on atmospheric processes over complex terrain. Dr. Whiteman’s is internationally recognized for his ability to design and conduct field research that tests scientific hypotheses and provides new insights into the underlying processes governing boundary layer processes over complex terrain. Along with Professor Sebastian Hoch, he serves as a lead investigator for the Meteor Crater Experiment (METCRAX), an ongoing meteorological research program supported by the National Science Foundation and U.S. Army to investigate the structure and evolution of temperature inversions and cold-air pools that form on a daily basis in topographic basins and valleys. The project included an intensive month-long field program during October 2006 in Arizona's Meteor Crater.
Global and Regional Climate
Professor Thomas Reichler is a climate modeler and analyst who is interested in the relationship between climate
change and atmospheric dynamics. He performs numerical experiments with climate models
to study how jet streams, storm tracks, and other key-features of the general circulation
are responding to climate change and how this affects global precipitation patterns
and other aspects of surface climate. Prof. Reichler also investigates the role of
the stratosphere for tropospheric weather and climate, research that may help to improve
the predictability of weather on weekly to monthly time scales and the certainty of
future climate predictions. He also develops objective performance measures for climate
models, which can be used to optimally construct multi-model climate predictions.
Our department has a long history of research on Southern Hemisphere weather and climate that has involved many fruitful collaborations with our colleagues in South America. Professors Julia Nogues-Paegle and Jan Paegle have spearheaded these efforts with contributions from many former and present faculty members. Julia and Jan have individually or as a team pioneered our understanding of the South American monsoon system. Although "retired," Julia and Jan remain active Emeritus Professors, both within the department and in the international science community. Their legacy is now being carried forward by Prof. Reichler, who recently began a regional climate modeling effort for South America to examine how the interaction between large-scale forcings, regional land-surface conditions, and the complex topography of the Andes Mountains influences seasonal forecast skill.
Professor Court Strong’s research focuses on interactions between the atmosphere and other components of the climate system, including the biosphere, hydrosphere, and cryosphere. His published work documents historical trends in the position and strength of jet streams, shows how sea-ice variability interacts with the overlying atmospheric circulation, and illustrates the role of tropospheric Rossby wave breaking in a variety of climate phenomena including modes of atmospheric and sea-surface-temperature variability. His work involves statistical methods for analyzing large geophysical data sets, simple numerical models such as linear stochastic difference equations, and global climate simulations customized to explore feedback sensitivities. Efficient, objective analysis methods are important to the process of uncovering new understanding, and Professor Strong has developed novel and effective techniques for the detection and analysis of jet streams and tropospheric Rossby wave breaking.
Professor John Lin seeks to understand the exchange of greenhouse gases, pollutants, and water between the atmosphere and the land surface. Exchanges at the atmosphere-land interface are significantly impacted by human activities, with consequences for the weather, climate, water resources, and air quality. Professor Lin’s research group makes use of atmospheric measurements containing signals of surface fluxes and interpret them using numerical models. He is a leader in developing and applying Lagrangian atmospheric models for such purposes. He is one of the primary developers of the Stochastic Time-Inverted Lagrangian Transport (STILT) model, which has been widely applied at multiple research institutions around the world to understand the sources/sinks of CO2 and other greenhouse gases. Professor Lin’s research is highly interdisciplinary, combining atmospheric science with biology, remote sensing, chemistry, and engineering
Cloud, Boundary Layer, Turbulence, and Weather Modeling
Professor Steve Krueger uses cloud resolving models such as the Utah Cloud Resolving Model (UU CRM) to study deep convective cloud systems. He uses CRMs for cloud process studies and to improve the representation of cloud-radiative properties in coarser resolution models, such as those used for medium-range weather prediction and climate modeling. He also uses smaller-scale models such as the Utah Large-Eddy Simulation (UU LES) model to study boundary layer cloud systems including stratocumulus clouds, trade cumulus clouds, convective plumes produced by Arctic leads, and interactions of the boundary layer with deep convection, as well as wildfire behavior. In order to better understand the interactions of turbulence and cloud microphysics, Steve's group has developed a novel numerical modeling framework. The Explicit Mixing Parcel Model (EMPM) includes all scales of turbulence in a 1D model that simulates entrainment, mixing, and the condensational growth of individual cloud droplets including the impact of aerosol properties. CLUSCOLL is an economical 3D model that simulates the impact of the smallest scales of turbulence on the clustering and collisional growth of cloud droplets. Steve has been involved with many field programs in order to collect data with which to verify and improve these models. He also collaborates with Dr. Mary Ann Jenkins of York University and Dr. Ruddy Mell of the National Institute for Standards in developing a coupled atmosphere-wildfire modeling system. The long-term goal of this collaboration is to develop a prototype real-time wildfire prediction system.
An expert in numerical weather prediction, data assimilation, and atmospheric predictability, Professor Zhaoxia Pu uses observations collected by satellites, radars, surface stations, weather balloons, and aircraft to improve forecasts produced by numerical weather prediction models. She works with many of the world's leading modeling systems, including the National Centers for Environmental Prediction Global Forecast System and North American Mesoscale Model. Her recent research efforts involve the use of remotely sensed data from NASA satellites (e.g., TRMM, Aqua, QuickSCAT, etc.) and NOAA airborne Doppler radars to improve the prediction of tropical storms, such as hurricanes and typhoons. She is also working on the targeting of weather observations to enhance the predictability of weather systems 1 to 14 days in advance, and the use of observing system simulation experiments to support the development of the nation's next generation satellites for global wind profile measurements. Prof. Pu, along with Prof. John Horel, also receives support to improve the assimilation of surface observations over complex terrain.
Professor Jan Paegle is an Emeritus Professor with more than 30 years of experience developing numerical weather prediction models. He continues to research atmospheric predictability using his global and limited area models known as the Global Utah Model and Utah Limited Area Model, respectively.
Professor Zhaoxia Pu's recent efforts have also included high-resolution numerical simulations of tropical
cyclones with the assimilation of satellite, radar and in-situ observations. Her specific
interest is understanding the dynamic and physical processes that control tropical
cyclone formation and rapid intensification.
The Deep Convection and Tropical Cyclones Research Group
Professor Ed Zipser and Research Assistant Professor Adam Varble lead this group with research focused on better understanding and predicting the life cycles of deep convective systems and tropical cyclones around the world using aircraft in situ measurements, ground-based and space borne remote sensing observations, and multi-scale model simulations. Current research is focusing on:
- processes that differentiate between intensifying and non-intensifying tropical cyclones,
- satellite retrieval of extreme rain rates,
- connections between rainfall event characteristics and large-scale environmental conditions,
- processes that lead to lightning production in oceanic storm systems,
- improvement of microphysics parameterizations and simulations of deep convection,
- environmental controls on deep convective initiation and upscale growth of the convective systems,
- properties of high ice water conditions with low radar reflectivity that are hazardous to aircraft and the processes that produce them, and
- improving detection of potentially hazardous conditions for aircraft using radar observations.
To obtain requisite measurements for the above listed research, our group actively participates in large multi-country, multi-agency field campaigns around the world. Recent examples include NASA GPM satellite validation campaigns across the US, the GRIP and HS3 tropical cyclone campaigns in the Atlantic Basin, and the HAIC-HIWC project in Darwin, Australia and Cayenne, French Guiana. Upcoming experiments include the CACTI and RELAMPAGO campaigns in Argentina.