Global Warming Experiments
Two experiments related to global warming have been conducted on KAEFS. The first, long-term experiment consists of 6 sets of paired plots, half of which have been warmed 2 °C above ambient since November, 1999. Nested in this design are clipped plots that mimic one of the dominant land uses of the KAEFS region, hay mowing.
The Oklahoma Mesonet
The Oklahoma Mesonet maintains the Washington Mesonet Station (WASH) at KAEFS. It is one of 121 Mesonet stations located across Oklahoma. Oklahoma Mesonet data are used by students and faculty at OU, scientists at other universities, Oklahoma public safety officials, K-12 outreach, Oklahoma Electric Cooperatives, and the Oklahoma agricultural community.
Drought Manipulation Experiment
As part of a coordinated global ecological network (DroughtNet) to assess grassland sensitivity to drought, we have established a rainfall manipulation experiment where we generated a gradient of rainfall reduction and addition. Rainout shelters, which exclude different precipitation amounts (0%, 20%, 40%, 60%, 80%, 100% and 50% addition), have been established in an existing prairie ecosystem at KAEFS during winter 2016. During Fall 2016, we have also incorporated a hay harvest treatment by hand clipping the vegetation in one 1-m2 subplot within each experimental plot, leaving a unclipped control to assess the effect of land management along a precipitation gradient. We are tracking ecological responses across differing levels of biological organization ranging from leaf physiology (carbon and water exchange) to plant community diversity, to ecosystem level function (plant productivity) and physiology (net ecosystem carbon and water exchange).
Unmanned Aerial Systems
The Center for Autonomous Sensing and Sampling (CASS) hosts and operates an unmanned aerial system research facility at the Kessler Atmospheric and Ecological Field Station. Collaboration between the Schools of Meteorology, Electrical and Computer Engineering, Aerospace and Mechanical Engineering, and Aviation Studies is providing unique opportunities to examine and characterize the atmospheric boundary layer and lower free troposphere. These studies fuse measurements from instrumented towers, ground-based remote sensing equipment, and state of the art unmanned aircraft equipped with advanced sensor packages. Current research projects include thermodynamic, kinematic, and chemical profiling, turbulence, heat, and mass flux measurements, vegetation monitoring, long-range antenna development, sensor validation, and systems development. Additionally, this space is being used to test prototypes for the 3D Mesonet in conjunction with the Oklahoma Mesonet and the Advanced Radar Research Center (ARRC).
Eastern Red Cedar Encroachment
The western portion of KAEFS has been left unmanaged for over 50 years and provides an excellent opportunity to study grasslands experiencing Eastern Red Cedar (ERC) encroachment, and the physiological performance of encroaching ERC individuals of varying size and age. Water sourcing (using hydrogen and oxygen isotopes), transpiration (Granier style sapflux probes) and drought tolerance traits are being monitored in a closed canopy ERC forest along with a newly encroached adjacent grassland. Additionally, an ERC seedling survival/mortality and demography study is currently underway and will continue to monitor seedling status from year to year.
Solar-Induced Flourescence Monitoring
Recent advancements in the observation of solar-induced fluorescence (SIF) offers new possibilities to monitor and quantify the photosynthetic activity of terrestrial ecosystems. SIF is generated from the photosynthetic process with a spectral range of about 650-800 nm, with two peaks in the red and far-red spectral regions. It is driven by absorbed photosynthetically active radiation (APAR) and can help reveal how APAR is partitioned by leaves for photosynthesis, non-photochemical quenching, or fluorescence. To better understand the relationship between SIF and photosynthesis, a FluoSpec (a continuous canopy-level SIF measurement system) was deployed at KAEFS. Specifically, the scientific questions being addressed include: (1) What is the relationship between photosynthesis and SIF at different time scales? (2) How does the SIF signal vary with environmental stress (drought or heatwave)? (3) What drives the variability of SIF during environmental stress?
Radar Research (ARRC Site)
KAEFS is an ideal location for variety of radar related precipitation studies because radar data from the WSR-88D KTLX and KOUN (research) radars above KAEFS are not contaminated by the ground clutter. To detect specific hydrometeors at the surface, 2-D Video Disdrometer - 2DVD data collection at this location began in 2006 and is ongoing. Further, during 2011 a Micro Rain Radar - MRR was added to the site. In addition, two parsivels, a heated bucket, temperature/humidity, and pressure sensors were deployed in 2014/2015. The newest addition, Pluvio2 L 400, weighing precipitation gauge, was installed this October 2018. The data are collected stored on the computers located at the site and instrumentation calibration is performed periodically, roughly two times per year, or if otherwise needed.
DOE ARM Site
The U.S. DOE Atmospheric Radiation Measurement (ARM) Program manages the Southern Great Plains site in Kansas and Oklahoma. It is the largest and most extensive climate research field site in the world and consists of 29 measurement facilities in Kansas and Oklahoma. ARM scientists focus on obtaining field measurements and developing models to better understand the processes that control solar and thermal infrared radiation transfer in the atmosphere (especially in clouds) and at the earth’s surface. KAEFS hosts one of the measurement facilities (Boundary Facility 6), which contains one microwave radiometer used to measure vertical column-integrated amounts of water vapor and liquid water, one ceilometer used to measure cloud base height and potential back scatter by aerosols, and one temperature, humidity, wind and pressure measuring system. The ARM facility at KAEFS was officially decommisioned in 2016.
Magnetometers study the electromagnetic environment of the Earth and space. Most of the magnetic field observed at ground level comes from deep within the Earth. Ground magnetometers measure magnetic induction due to electric currents flowing in the ionosphere at an altitude of approximately 100 kilometers which are closely connected to the variations in the magnetosphere and beyond. The highly varying activities on the Sun drive this so-called "space weather". Dr. Peter Chi form UCLA placed a magnetometer at KAEFS in spring 2006 in order to fill in a gap between units located in Dallas, TX and Wichita, KS and thus creating a network in the South Central United States where high-resolution magnetic measurements for space weather studies are lacking. The KAEFS magnetometer plays a role in an active research project that uses the ground measurements of field line resonance to remotely monitor the plasma density distribution in the magnetosphere. Through the participation in instrument operation and data inspection, students can obtain hands-on experience of space weather research in action.