Operations Updates
ARM Climate Research Facility Operations Update - January 15, 2007
This bimonthly report provides a brief summary of significant accomplishments and activities in the operations area of the ARM Climate Research Facility (ACRF).
Radon Measurements to Help Scientists Estimate Carbon Dioxide Exchange
Researchers installed a continuous 222Rn monitor at the base of the 60-meter tower at the SGP Central Facility. A sampling tube connected to the tower supplies air to the container, where the radon is measured.
In November, ARM scientists and researchers from the National Oceanic and Atmospheric Administration's Climate Monitoring and Diagnostics Laboratory began a collaborative field campaign at the ACRF Southern Great Plains (SGP) site. The science objective of the Radon Measurements of Atmospheric Mixing (RAMIX) field campaign is to quantify the mixing rate of air between the surface and the atmospheric boundary layer—the layer of air from Earth's surface up to about 1 km. This information is valuable for studies of the terrestrial carbon cycle and cloud formation. In particular, uncertainties in estimates of regional carbon dioxide (CO2) exchange (that rely on models of atmospheric transport) are dominated by model error in the vertical mixing rate. The RAMIX campaign will provide an independent measure of mixing rate that scientists will combine with measured variations in atmospheric CO2 mixing ratio to estimate regional CO2 exchange.
Carbon dioxide is a greenhouse gas and has been identified as a major contributor to global warming. Because terrestrial vegetation absorbs carbon dioxide from the atmosphere and stores the carbon in soils, scientists believe that carefully chosen land use and management (e.g., conservation tillage) can be effective in reducing global warming. Measuring the regional carbon exchange is one way of measuring the net rate at which warming and cooling is occurring.
Radon (222Rn) provides a valuable tracer of atmospheric mixing because it is emitted relatively ubiquitously from the land surface and has a short enough half-life (3.8 days) to allow characterization of mixing processes based on time variations and/or vertical profile measurements. To provide accurate estimates of atmospheric mixing rate, the RAMIX team will use both 222Rn concentration measurements and a spatially explicit model of surface 222Rn flux that will be tested with in situ measurements. Beyond the tower measurements of 222Rn, airborne 222Rn concentration measurements will increase the accuracy of the mixing rate estimates. Data from RAMIX are expected to contribute to a separate but related measurement and modeling effort, the Aircraft Carbon field campaign, which will also assess the nature of the carbon cycle by looking at carbon profiles in the atmosphere.
New ACRF Exhibit Makes Debut at Fall Meeting of American Geophysical Union
The new ACRF display made its debut at the 2006 Fall Meeting of the American Geophysical Union (AGU) in December in San Francisco.
ACRF staff returned to San Francisco in December 2006 for the 2006 American Geophysical Union (AGU) Fall Meeting, this time with a new exhibit. With over 1,120 sessions and 13,023 abstracts to choose from (an increase of more than 15 percent over the 2005 Fall Meeting), another attendance record was set. Nearly 14,000 scientists from around the world crowded the halls of the Moscone Center to share their research on Earth and space sciences. Former Vice President Al Gore also made an appearance on December 14, holding a Town Hall Meeting on "Climate Change: The Role of Science and the Media in Policymaking."
Meeting attendees were drawn to the new, modern exhibit, where ACRF staff fielded questions regarding ARM data availability and accessibility. ACRF staff also shared the ACRF mission and goals with interested participants and provided information regarding the ARM science program and the newly formed ARM Aerial Vehicles Program. And once again, the ACRF Education and Outreach climate change coloring and activity book was a popular item for visiting teachers and students.
ARM researcher Dr. Jennifer Comstock shares her ARM experience with an interested postdoctoral applicant.
Numerous posters and talks at this year's AGU meeting used data from many of ACRF's field campaigns, such as the Tropical Warm Pool-International Cloud Experiment, the Mixed-Phase Arctic Cloud Experiment, and the ARM Mobile Facility's deployments at Point Reyes National Seashore and Niamey, Niger, West Africa. ARM researchers, including ARM's Chief Scientist Warren Wiscombe, presided over several sessions. Dr. Wiscombe was also an invited speaker during the Atmospheric Sciences session on Light Scattering and Radiative Transfer: Basic Research and Applications. Researchers sponsored by ARM/ACRF routinely attend the regularly scheduled AGU meetings each year. The AGU is an international scientific society of over 41,000 members, and is a leader in the increasingly interdisciplinary research area of geophysical sciences.
