The living biosphere interacts with atmospheric processes at a multitude of scales. Understanding these processes requires integration of multiple observations for comparison to theories embedded in atmospheric models. The Chequamegon Heterogeneous Ecosystem Energy-balance Study Enabled by a High-density Extensive Array of Detectors (CHEESEHEAD) was an intensive field-campaign conducted in June-October 2019 to specifically address long-standing puzzles regarding the role of atmospheric boundary-layer responses to scales of spatial heterogeneity in surface-atmosphere heat and water exchanges.

The field campaign was held mid summer to early fall 2019 in a 10x10 km domain around the existing infrastructure Park Falls, WI in a mixed upland-lowland landscape. Various groups evaluated aspects of the atmosphere including diagnosing planetary boundary layer development and its influence by vegetation, observing and modeling the relationship between eddy-covariance (EC) flux tower measurements of the surface energy balance with atmospheric properties, and evaluating parametric and machine-learning-based methods for scaling surface energy fluxes for improving model-data comparison.

The project included nearly 70 partners, including 40 in the field, and several add-on projects from collaborators at Karlsruhe Institute of Technology (DFG), NOAA ATDD, NOAA ESRL, NASA GSFC, Montana State University, and others. The experimental design was numerically optimized through a science traceability matrix in combination with novel high resolution large eddy simulation (LES) modeling and observing system simulation experiments. Nineteen EC towers, numerous ground-based atmospheric profilers, 90 hours of airborne EC and atmospheric profiling, and a range of ecological and land surface sampling on ground, drone, and aircraft were successfully deployed across four months with three intensives.

The very high-density EC flux tower network sampled surface energy fluxes and meteorology across a heterogeneous forest landscape representative of much of the mid-latitudes. Airborne spectroscopy imaging mapped leaf chemistry and canopy properties for scaling purposes. Several groups made a variety of atmospheric profiles of winds, temperature, and humidity via drones, sounding instruments, and LiDARs. All of these data are publicly available on the National Center for Atmospheric Research (NCAR) Earth Observing Laboratory (EOL) repository.

Nearly 8 million core hours of supercomputing time was allocated with NCAR to conduct an experiment-wide nested grid 30x30 km 8-member ensemble 6-meter inner resolution high resolution LES for two cases within each of two intensive observation periods with either homogenous and heterogenous surface forcing.

CHEESEHEAD19 results supported directly from this award have been documented in 23 peer-reviewed publications to date and several in review, which demonstrated the nature of energy imbalance in eddy covariance towers, conclusively linked it to large eddy transport as the largest contributor, and evaluated various correction mechanisms, leaning toward heterogeneity-parameter similarity theory corrections or Environmental Response Function (ERF) based flux mapping as positive candidates while ruling out the viability of previously proposed spatial eddy covariance matrix approaches.

The intellectual merit of these findings help advance our capability to observe, diagnose, and improve surface energy balance and its relationship to surface heterogeneity and atmospheric mesoscale variability. The permanent archive of these observations and the add-on activities that surrounded the project have led to lasting broader impacts to diverse disciplines from atmospheric sciences (including boundary-layer meteorology, micrometeorology, cloud physics, numerical weather prediction, and atmospheric radiation), but also to biogeosciences, ecosystem ecology, and hydrology. Numerous modeling and synthesis groups have been engaged such as DOE Reducing Uncertainty in Biogeochemical Interactions Through Synthesis and Computation (RUBISCO) and the Coupling of Land and Atmospheric Subgrid Parameterizations (CLASP) project. 

The project also engaged numerous public stakeholders through open-houses, incorporation of middle and high school classrooms with the GLOBE program, and public talks and print and social media engagement. The project supported a diverse team, including four graduate students and one postdoc and several early career scientists, one high school student, and one REU student, which were 40% women and 40% underrepresented minority. NSF ADVANCEGeo sexual harassment training was incorporated into the field component and later supported a peer-reviewed publication on outcomes on safe and inclusive fieldwork across multiple field projects. Workshops at national conferences, two virtual special meetings on land-atmosphere interactions, and a special collection on scaling in a suite of journals supported scientific community training and engagement.

Last Modified: 04/29/2024
Modified by: Ankur R Desai