This award supports measurements of a suite of volatile organic compounds (VOCs), including oxygenated volatile organic compounds (OVOCs), non-methane hydrocarbons (NMHCs), halocarbons, and some nitrogen and sulfur containing species, onboard the NSF-GV Aircraft during the Deep Convective Clouds and Chemistry (DC3) field campaign. The DC3 program will investigate the influence of deep convective systems on the composition and chemistry of the mid-latitude upper troposphere and lower stratosphere using two aircraft in combination with ground based instrumentation. The program will occur in three locations: 1) northeastern Colorado, 2) central and western Oklahoma, and 3) northern Alabama allowing for the assessment of different types of storms and different boundary layer compositions and convective environments. The instrument supported through this award is an airborne fast gas chromatograph/mass spectrometer that was recently developed specifically for the GV- the TOGA (Trace Organic Gas Analyzer). This instrument will measure organic compounds with high accuracy, precision, and low detection limits (about 10 ppt to 1 ppt) at a sampling rate of 2 minutes or less. The instrument will provide data necessary to define the linkages among atmospheric chemical composition, mid-latitude convection, and upper troposphere/lower stratosphere (UT/LS) chemistry. Organic compounds specific to these issues, including tracers of anthropogenic and biogenic activity, chemical precursors and intermediates, and oxidation products will be measured throughout the troposphere and extending into the Upper Troposphere/Lower Stratosphere (UT/LS) region. These measurements will allow testing of several of the hypotheses integral to the DC3 program and help achieve the two primary goals of DC3, which are: 1) Quantify and characterize of the convective transport of fresh emissions and water to the upper troposphere within the first few hours of active convection, investigation of storm dynamics and physics, lightening and its production of nitrogen oxides, the effect of cloud hydrometeors on scavenging of species, surface emission variability, and chemistry in the anvil; and 2) Quantify the changes in chemistry and composition in the upper troposphere after active convection, focusing on 12-48 hours after convection and the seasonal transition of the chemical composition of the UT. The broader impacts of this project include education and technical training, outreach, and the societal importance of understanding atmospheric processing related to air quality and climate. This project will provide support for the graduate research of a student.
