The ability to measure, model, and analyze atmospheric processes is essential to understanding our ever-changing, dynamic planet. EVS measurement capabilities range from remote sensing and surface meteorology instruments, to instrumentation designed to quantify the land-atmosphere exchange of energy, water, and greenhouse gases. Our modeling capabilities begin with regional-scale climate, air quality, and aerosol modeling and extend to global chemical transport models, general circulation models of the atmosphere, models of the biosphere, and coupled Earth systems models. Our strength is our ability to develop models, methods, and datasets that bridge the gap between observations and computer simulations of the atmosphere.
Climate Observation Facility Operation
EVS provides operational management for DOE’s Southern Great Plains Facility in Oklahoma, part of its Atmospheric Radiation Measurement (ARM) Program. The facility, established in 1992, is the first and largest of the ARM Program's fixed-field research sites; it is also home to the ARM Climate Research Facility, a DOE Office of Science user facility. The ARM Program's fixed-field and mobile facilities provide data from strategically located, in situ and remote sensing observatories around the world. These data are publically available and are intended to improve the representation and understanding, in climate and earth system models, of clouds and aerosols as well as their interactions and coupling with the earth's surface.
EVS has nearly four decades of expertise in observations, instrumentation, and modeling of micrometeorological processes in the atmospheric surface layer, as well as in probing the atmospheric boundary layer and its properties with in situ and remote sensing instrumentation.
We manage surface meteorological instrument systems for the ARM Program, AmeriFlux, and the Argonne Emergency Management System. The surface-based observations we make provide a direct measure of atmospheric phenomena. We also use the eddy covariance and Bowen ratio techniques to measure the land surface exchange of water vapor, heat, momentum, carbon dioxide, methane, other greenhouse gases, and air pollutants.
We humans inhabit and deploy our instruments in only a small fraction of the atmosphere. To understand the four-dimensional nature of our weather (time being the fourth dimension), we must employ remote sensing technologies that use various wavelengths of electromagnetic energy as probes. The EVS remote sensing group has expertise in a variety of measurement techniques:
- Passive sensors, including microwave radiometers and broadband and multi-band radiometers, measure solar and Earth radiances, as well as total column water vapor. Passive sensors analyze the natural radiation they receive.
- Active sensors, including sodars, radars, and lidars of various frequencies, measure vertical profiles of wind, aerosols, precipitation, and atmospheric turbulence. Active sensors emit energy and then detect and measure the radiation that is reflected or backscattered from targets.
In addition to the measurements made by passive and active remote sensors, we develop retrieval algorithms to extract geophysical meaning from the remotely sensed data, deploy instruments for field experiments across the globe, and publish the results in the scientific literature to improve understanding of climate change, wind energy, atmospheric transport and diffusion, and precipitation processes.
Modeling and Analysis
EVS develops and evaluates models of the atmosphere and biosphere at regional to global scales. Our expertise includes the following:
- Model aerosol-cloud interactions, aerosol chemistry and transport, and radiative forcing in the atmosphere.
- Develop representations of crops in global-scale models of the biosphere.
- Analyze and support air quality and meteorological assessments for multidisciplinary environmental impact statements.
- Develop open-source and community-supported software and applications that help convert raw observational data from radars, wind profilers, and microwave radars to geophysical variables that are suitable for model evaluations and the development of process parameterizations, such as the Python-ARM Radar Toolkit.
- Develop high-resolution regional-scale climate models (12 km resolution) that evaluate climate change impacts on hydrology and ecology (including agriculture). The model results are better at forecasting seasonal features and extreme weather events than previous models, adding accuracy to climate predictions, especially in places with sharp terrain changes like the Rockies. The dataset will soon be available online.