Tall Tower Trace Gas Observatory
The Tall Tower Trace Gas Observatory has been supported by the National Science Foundation, Lower Atmosphere Chemistry Section (ATM-0546476), the Office of Science (BER) United States Department of Energy (DE-FG02-06ER64316), and the United States Department of Agriculture - National Institute of Food and Agriculture (USDA NIFA/2010-65112-20528). Current support is provided by the United States Department of Agriculture - National Institute of Food and Agriculture (USDA NIFA/2013-67019-21364). We express our sincere thanks to Minnesota Public Radio (KCMP 89.3 "The Current") and Tom Nelson for their logistical support.
Since spring 2007 measurements at the tall tower have included carbon and oxygen isotopes of CO2 based on laser spectroscopy, and traditional eddy fluxes of energy, water, and carbon. Carbon isotope measurements were discontinued in 2010. Nitrous oxide concentrations have been measured near continuously since spring 2010. Water vapor isotope measurements were initiated in spring 2010 and are on-going.
Carbon dioxide mixing ratio data from the Trace Gas Observatory have been used to help support the Ring 2 High-precision, high-accuracy CO2 mixing ratio measurements in support of the North American Carbon Program Mid Continent Intensive. For more information see RING2.
Citation: Miles, N.L., S.J. Richardson, K.J. Davis, A.E. Andrews, T.J. Griffis, V. Bandaru, and K.P. Hosman. 2013. NACP MCI: CO2 Flux Tower Measurements, Upper Midwest Region, USA, 2007-2009. Data set. Available on-line [https://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA. http://dx.doi.org/10.3334/ORNLDAAC/1202
Our current work is bringing together relatively long-term observations from the tall tower and modeling (WRF, WRF-STILT, WRF-CHEM, WRF-LES) to help interpret these long term bounday layer observations and to help constrain the budgets of water, carbon, and nitrogen at the regional scale.
Land use within the footprint of the tall tower.
Sonic anemometer-thermometer and air sample inlet mounted at 100 meters.
Tunable diode laser systems for measuring the oxygen and deteurium isotopes in water vapor and nitrous oxide and carbon dioxide concentrations.
Example of WRF nested model domain for examining sources/sinks of atmospheric water within the tall tower domain.
Influence of Agriculture on the Hydrologic Cycle in the Upper Midwest, United States
Combining tall tower and field-scale eddy covariance flux observations with WRF to examine the impact of agricultural activities on regional hydrology.
Using post-processing software such as VAPOR to examine advection of water vapor into the region and to help interpret changes in the isotope composition of water vapor at the tall tower.