Title: Deep Convective Clouds and Chemistry DC3 Field Experiment
1Deep 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
Lenschow Owen Cooper Andy Weinheimer Paul
Krehbiel Jeff Stith Alan Fried
2DC3 Characterize the effects of continental,
midlatitude deep convection on the transport and
transformation of ozone and its precursors
- Processing in the convection,
- Processing in the anvil
- Processing in the convective outflow 12-48 hours
later - Contrast different types of convection and
different emission regions
http//utls.tiimes.ucar.edu/Science/dc3.shmtl
3Ancillary Objectives of DC3
- Halogen Chemistry in the UTLS
- Determine mass fluxes of air and trace gases into
and out of the storm, - Cloud electrification and lightning discharge
processes - Effects of deep convection on UT water vapor
- Convective processing of aerosols and their
impact on water and ice particles
http//utls.tiimes.ucar.edu/Science/dc3.shmtl
4A Storm Penetrating Aircraft (SPA) can help reach
these objectives
- Processing of trace gases in the convection,
- Processing in the anvil (mid to lower regions)
- Cloud electrification and lightning discharge
processes - Effects of deep convection on UT water vapor
- Convective processing of aerosols and their
impact on water and ice particles
5Importance of Production of NOx by Lightning
Barth et al., 2006, submitted to JGR
6Cross Section of CO
CO used as a tracer of boundary layer air
ppbv
Barth et al., 2006, submitted to JGR
7Soluble Species and Their Fate in Deep Convection
Total CH2O mixing ratios gas cloud water
rain ice snow hail
Barth et al., 2006, submitted to JGR
8Transects across Anvil
Disagreement among models, but no observations
available
Barth et al., 2007, in preparation
9Priority Instruments on a SPA to Understand
Convective Processing of Constituents
- NO
- 150 lbs., 10 pptv detection limit, and 0.5-sec
time response - (courtesy of Andy Weinheimer, NCAR)
- CO
- Soluble Species
- Formaldehyde, Hydrogen Peroxide, Nitric Acid
10(No Transcript)
11Ozone in the UT/LS region is important for
climate change and for affecting the UV radiation
reaching the Earths surface. Deep convection
alters the composition of the UT/LS
region. Important precursors of O3 are NOx, HOx,
and the HOx precursors.
12Previous Studies of Convection and Chemistry
- 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
13Goals 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,
14Goals of DC3
2. To determine the role of anvil dynamics,
multiphase chemistry, microphysics, radiation,
and electrification on the chemical composition
of convective outflow,
15Goals of DC3
3. To determine the effects of convectively-pertur
bed air masses on ozone and its related chemistry
in the midlatitude upper troposphere and lower
stratosphere 12-48 hours after the near
convection region is sampled,
CO at z 10.6 km 00 Z 15 June 1985
06 Z 15 June 1985
Modeling study showing convectively-transported
CO advection downwind of active convection. From
Park et al. (2004)
12 Z 15 June 1985
16Goals of DC3
4. To contrast the influence of different surface
emission rates on the composition of convective
outflow.
NOx emissions
Isoprene emissions
17Ancillary Goals of DC3
- To determine partitioning of reactive halogen and
reservoir species in the UTLS - 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) - To improve our understanding of cloud
electrification and lightning discharge processes
- 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 - To connect aerosol and cloud droplet and ice
particle number concentrations with convection
characteristics and trace gas convective
processing
18Facilities
- 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)
19Setting
Annual Average Precipitation
- 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
20Northeastern Colorado
- Facilities
- CHILL and PAWNEE radars in place
- Need portable LMA installed
- Chemistry
- Agricultural emissions
- Denver emissions likely to be sampled
- Convection
- Variety of single, multi and super cell
convection - Lightning peaks in July
Figure from Brenda Dolan (CSU)
21Oklahoma
- Facilities
- LMA in place
- Have both Doppler and polarimetric radars
- Chemistry
- Urban emissions from Oklahoma City
- Agricultural emissions nearby
- Isoprene emissions in eastern Oklahoma
- Convection
- large storms dominate in May and June (tornado
season) - air mass storms dominate in July and August
- Lightning peaks in late June
22Northern 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
23Recommendations 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
24Working Groups
- Climatology (O. Cooper)
- Forecasting Convection and Downwind Plumes
(M. Weisman) - Airborne Platforms (A. Fried)
- Ground-based Platforms (D. MacGorman, S.
Rutledge) - Flight Plans to address Science Goals (D.
McKenna) - Satellite Data Contribution (L. Pan)
- Linking Models and Observations (K. Pickering)
- Education and Outreach (D. Rogers, S. Rutledge)
25Timeline
- 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