Based upon a submitted Scientific Program Overview (SPO) document for the Deep Convective Clouds and Chemistry (DC3) field campaign, this preliminary effort will focus on support of required coordination of potential DC3 investigators planning this large experiment.
If supported, DC3 will investigate the impact of deep, mid-latitude continental convective clouds, including their dynamical, physical, and lightning processes, on upper tropospheric (UT) composition and chemistry. DC3 will be requesting access to extensively instrumented aircraft platforms and ground-based observation systems. The NSF/NCAR Gulfstream-V (GV) aircraft would be the primary platform to study the high altitude outflow of the storms, and would be instrumented to measure a variety of gas-phase species, radiation, and cloud/precipitation particle characteristics. The GV would also document the downwind chemical evolution of the convective plume. The NSF/NCAR C-130 (or possibly the NASA DC-8) aircraft would complement the GV via in situ observations to characterize the convective storm inflow and provide remote sensing to aid in GV flight plan optimization and column characterization. Ground-based radar networks would depict the volumetric precipitation and kinematic characteristics of storms and provide guidance to the aircraft operations. The impact of lightning on outflow composition would be constrained through detailed measurements from VHF lightning mapping arrays. DC3 would thus surpass earlier experiments that addressed these topics by using advanced instrumentation not previously available. Satellite data would place the airborne and ground-based measurements in the context of the wider geographical region and help guide sampling strategies. At the same time, DC3 measurements would serve to augment satellite retrievals of atmospheric constituents such as nitrogen dioxide near storms.
Broader impacts of the planned field program would include extensive education and outreach activities and via improved understanding of sources of UT ozone, which is important to climate forcing and air quality, for assessment reports and resulting policy implications. Further, DC3 measurements would be instrumental in improving model parameterizations of convective transport, production of nitric oxide by lightning, and wet deposition of chemical species. Undergraduate and graduate students would participate in DC3 in a variety of ways including airborne and ground-based observations, design and construction of instruments, operation and improvement of numerical models, precipitation collection and analysis, and reporting of the results to the scientific community through presentations and publications. Outreach and media days during the field campaign would provide a valuable means to engage the public in atmospheric science.
Intellectual merit and broader impacts: This grant supported preparing for the Deep Convective, Clouds and Chemistry (DC3) field project. The PI was heavily involved in the planning stage, attending multiple meetings with the other DC3 PI’s, participating in numerous telecons, etc. In carrying out DC3 a very unique dataset was obtained regarding the dynamics, microphysics, electrification and chemical aspects of deep convection. One particular noteworthy accomplishment with significant intellectual merit is the fact that DC3 was able to collect such data in three distinct meteorological regions, Colorado, Oklahoma and Alabama. Furthermore, these three regions represent diverse chemical environments. DC3 collected data on isolated severe convection, isolated non-severe convection and two Mesoscale Convective Systems. The highest lightning generated NOx concentrations were observed in the MCS case in mid June. Another exciting data collection period for DC3 occurred around the High Park fire period in Colorado. A series of storms were observed on 27 June. Storms that ingested smoke from the fire appeared similar to nearby storms forming in smoke free air, from the perspective of radar observations. However the "smoke" storms were inverted electrically, that is, they had charge structures with positive charge situated beneath negative charge. The smoke free storms had normal polarity, with negative charge situated at lower heights compared to positive charge. These cases are the focus of current studies. Although the impact of DC3 can only be measured by forthcoming knowledge gained and the generation of peer reviewed studies, one broader impact that is readily evident is the merger of the meteorological and atmospheric chemistry communities to study the coupling between storm dynamics and chemical production and transport. This collaboration was very evident during the field phase.
