Deep Convective Clouds and Chemistry (DC3) Field Experiment Principal Investigators: Mary Barth (NCAR), Bill Brune (PSU), Chris Cantrell(NCAR), Steve Rutledge (CSU) Steering Committee: Ken Pickering Jim Crawford Laura Pan Andrew Heymsfield Don LenschowOwen Cooper Andy Weinheimer Paul KrehbielJeff Stith Alan Fried

DC3: Characterize the effects of continental, midlatitude deep convection on the transport and transformation of ozone and its precursors 1.Processing in the convection, 2.Processing in the anvil 3.Processing in the convective outflow hours later 4.Contrast different types of convection and different emission regions

Ancillary Objectives of DC3 1.Halogen Chemistry in the UTLS 2.Determine mass fluxes of air and trace gases into and out of the storm, 3.Cloud electrification and lightning discharge processes 4.Effects of deep convection on UT water vapor 5.Convective processing of aerosols and their impact on water and ice particles

A Storm Penetrating Aircraft (SPA) can help reach these objectives: 1.Processing of trace gases in the convection, 2.Processing in the anvil (mid to lower regions) 3.Cloud electrification and lightning discharge processes 4.Effects of deep convection on UT water vapor 5.Convective processing of aerosols and their impact on water and ice particles

Importance of Production of NOx by Lightning Barth et al., 2006, submitted to JGR

Cross Section of CO ppbv CO used as a tracer of boundary layer air Barth et al., 2006, submitted to JGR

Soluble Species and Their Fate in Deep Convection Total CH 2 O mixing ratios = gas + cloud water + rain + ice + snow + hail Barth et al., 2006, submitted to JGR

Transects across Anvil Disagreement among models, but no observations available CH 2 O (gas) H 2 O 2 (gas) HNO 3 (gas) CO O3O3 O3O3 Barth et al., 2007, in preparation

Priority Instruments on a SPA to Understand Convective Processing of Constituents 1.NO 150 lbs., 10 pptv detection limit, and 0.5-sec time response (courtesy of Andy Weinheimer, NCAR) 2.CO 3.Soluble Species: Formaldehyde, Hydrogen Peroxide, Nitric Acid

Ozone in the UT/LS region is important for climate change and for affecting the UV radiation reaching the Earth’s surface. Deep convection alters the composition of the UT/LS region. Important precursors of O 3 are NOx, HOx, and the HOx precursors.

Comprehensive cloud and lightning with a fair amount of chemistry information –STERAO, EULINOX, ELCHEM, TROCCINOX, SCOUT Comprehensive chemistry with little cloud and lightning information –INTEX, TRACE-P Previous Studies of Convection and Chemistry

Goals of DC3 1. To quantify the impact of continental, midlatitude convective storm dynamics, multiphase chemistry, lightning, and physics on the transport of chemical constituents to the upper troposphere,

Goals of DC3 2. To determine the role of anvil dynamics, multiphase chemistry, microphysics, radiation, and electrification on the chemical composition of convective outflow,

Goals of DC3 3. To determine the effects of convectively-perturbed air masses on ozone and its related chemistry in the midlatitude upper troposphere and lower stratosphere hours after the near convection region is sampled, Modeling study showing convectively-transported CO advection downwind of active convection. From Park et al. (2004) CO at z = 10.6 km 00 Z 15 June Z 15 June Z 15 June 1985

Goals of DC3 4. To contrast the influence of different surface emission rates on the composition of convective outflow. NOx emissionsIsoprene emissions

Ancillary Goals of DC3 1.To determine partitioning of reactive halogen and reservoir species in the UTLS 2.To determine the mass fluxes of air and trace gases into and out of the storm, including entrainment (determine fraction of boundary layer air that reaches LS, UT; determine fraction entrained; determine what part of the boundary layer is ingested by the storm; determine quantity of stratospheric ozone entrained into anvil) 3.To improve our understanding of cloud electrification and lightning discharge processes 4.To investigate the role of deep convection in contributing to the UT water vapor and in the transport of water vapor into the lowermost stratosphere 5.To connect aerosol and cloud droplet and ice particle number concentrations with convection characteristics and trace gas convective processing

Facilities: High altitude aircraft: HIAPER Low altitude aircraft: NASA DC-8 or C-130 Ground based dual Doppler and polarimetric radars Lightning mapping arrays Others –Ground precipitation network –Discussion of other aircraft (A-10, DOE G-1)

Setting: Summer 2009 –6 week period –start and stop times are still being determined Northeast Colorado and Central Oklahoma and Northern Alabama –Sufficient ground-based facilities –Likelihood of convection occurring in one of the three places is good –Contrast different environments (long-lived, shear storms vs airmass storms; high cloud bases vs low cloud bases; low chemical emissions vs higher emissions) JJA Lightning Annual Average Precipitation

Chemistry: –Agricultural emissions –Denver emissions likely to be sampled Convection: –Variety of single, multi and super cell convection –Lightning peaks in July Northeastern Colorado Facilities: –CHILL and PAWNEE radars in place –Need portable LMA installed Figure from Brenda Dolan (CSU)

Oklahoma Facilities: –LMA in place –Have both Doppler and polarimetric radars Chemistry: –Urban emissions from Oklahoma City –Agricultural emissions nearby –Isoprene emissions in eastern Oklahoma 3-D 2-D Convection: –large storms dominate in May and June (tornado season) –air mass storms dominate in July and August –Lightning peaks in late June

Northern Alabama Facilities: –LMA in place –Have radars, ozone lidar, ozonesondes Chemistry: –High biogenic emissions Convection: –Shear-induced convection in May; airmass thunderstorms during June, July, August –Peak lightning in July Radar ranges and LMA location

Recommendations from Recent Workshop Prefer to sample isolated convection for analyzing convective processing of chemical species Base aircraft near Oklahoma City –Central location; can easily fly to NE CO or N.AL; longer endurance because of lower elevation (than JeffCo) Preliminary studies of forecasting convective plume downwind Need to address specific issues

Working Groups 1)Climatology (O. Cooper) 2)Forecasting Convection and Downwind Plumes (M. Weisman) 3)Airborne Platforms (A. Fried) 4)Ground-based Platforms (D. MacGorman, S. Rutledge) 5)Flight Plans to address Science Goals (D. McKenna) 6)Satellite Data Contribution (L. Pan) 7)Linking Models and Observations (K. Pickering) 8)Education and Outreach (D. Rogers, S. Rutledge)

Timeline Working Groups address specific issues (now – Sept) PIs and steering committee incorporate information into Science Plan and Experimental Design Overviews –Decisions on specific issues Draft of documents by Oct/Nov Submit proposal to NSF/OFAP by Jan 2007