Deep Convective Clouds & Chemistry
Experiment (DC3) |
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Principal Investigators
Contact PI:
Mary Barth
NCAR- ACD
303-497-8186
Chris Cantrell
NCAR- ACD
303-497-1479
William Brune
PSU
814-865-3286
Steven Rutledge
CSU
970-491-8283
Steering Committee
(includes those above)
Jim Crawford
NASA-Langley
757-864-7231
Owen Cooper
NOAA-CSD, CU-CIRES
303-497-3599
Alan Fried
NCAR-EOL
303-497-1475
Andrew Heymsfield
NCAR-MMM
303-497-8943
Paul Krehbiel
NMT
505-835-5215
Don MacGorman
U. of Oklahoma
405-325-5667
Laura Pan
NCAR-ACD, TIIMES
303-497-1467
Walter Petersen
NASA-MSFC
256-961-7861
Kenneth Pickering
NASA-Goddard
301-405-7639
Jeffrey Stith
NCAR-EOL
303-497-1032
Andy Weinheimer
NCAR-ACD
303-497-1444
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 Click figures to view the details
DC3 Experimental Design - January 2009
DC3 Science Plan - January 2009
The Deep Convective Clouds and Chemistry (DC3) field campaign will investigate the impact of deep,
midlatitude continental convective clouds, including their dynamical, physical, and lightning processes,
on upper tropospheric (UT) composition and chemistry. The campaign will make use of extensively
instrumented aircraft platforms and ground-based observations.
The NSF/NCAR Gulfstream-V
(GV) aircraft is the primary platform to study the high altitude outflow of the storms, and is instrumented
to measure a variety of gas-phase species, radiation, and cloud particle characteristics. The GV will also
document the downwind chemical evolution of the convective plume.
 The NSF/NCAR C-130 (C-130) aircraft
complements the GV via in situ observations to characterize the convective storm inflow and provides
remote sensing to aid in flight planning and column characterization.
Ground-based radar networks are
used to depict the physical and kinematic characteristics of storms and provide guidance to the aircraft
operations. The impact of lightning on outflow composition is constrained through detailed measurements
from VHF lightning mapping arrays.
DC3 surpasses previous experiments addressing these topics
by using advanced instrumentation not previously available. The DC3 field experiment also includes
ground-based collection of precipitation followed by chemical analysis. Satellite data are used to 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 help satellite retrievals of atmospheric
constituents such as NO2 near storms.
The observations will be conducted in three locations: 1) northeastern Colorado, 2) central Oklahoma, and
3) northern Alabama in order to gather data on different types of storms and with different boundary layer
compositions as well as to ensure sampling of convection during the time period of the field campaign.
The types of storms being sampled are air mass, multicell, and supercellular convection.
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Motivation |
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Schematic of a) a mature airmass thunderstorm and b) a squall line vertical cross section. Taken from the NOAA National Weather Service http://www.srh.weather.gov/srh/jetstream/index.htm. Superimposed on panel b are processes affecting chemical species that are ingested into storms. |
The upper troposphere and lower stratosphere (UTLS) is an important region for Earth’s climate because
water vapor, ozone, cirrus clouds and aerosols in this region strongly contribute to radiative forcing
of the climate system.
The UT and LS have very different chemical compositions resulting in strong gradients
across the tropopause. Further, the UTLS is a highly dynamic region influenced by a broad range
of scales, from deep convection and gravity waves, to tropospheric weather systems and the stratospheric
large-scale circulation.
Convective transport is a major pathway for rapidly moving chemical constituents
and water from the boundary layer to the upper troposphere and in some cases to the lower stratosphere.
Yet the impact of convective transport on the UTLS composition and chemistry has not been fully characterized
on either the global or continental scale.
Ozone in the UTLS region is important for climate change and for affecting the UV radiation reaching the Earth's surface. Ozone is produced from NOx and HOx radicals. Thus, quantifying the sources of NOx and HOx in the upper troposphere is key to understanding the climate implications of upper tropospheric O3. Deep convection alters the composition of the UTLS region.
DC3 is proposed to study the impact of continental, midlatitude deep convection on the UTLS
composition and chemistry above the continental U.S. during the lifetime of the storm itself and during
the period 12-48 hours after active convection.
DC3 will give us:
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Comprehensive chemistry on board a high-altitude and lower-altitude aircraft. The NSF/NCAR HIAPER and C-130 are being requested.
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Comprehensive storm information from ground-based Doppler and polarimetric radars
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Outstanding information on lightning location from lightning mapping arrays
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Science Goals |
 To quantify and characterize the convection and convective transport within the first few hours of active convection, investigating:
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storm dynamics and physics,
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lightning and its production of nitrogen oxides,
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cloud hydrometeor effects on wet scavenging of species,
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chemistry in the anvil
To quantify the changes in chemistry and composition after active convection, focusing on
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Ancillary Goals |
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Experimental Design
- DC3 Experimental Design - January 2009
- Platform & Payload Information - January 2009
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 High Altitude Aircraft
(e.g. NSF/NCAR G-V)
outfitted with gas-phase and aerosol characterization instrumentation to sample convective outflow |
 Low Altitude Aircraft
(e.g. NSF/NCAR C-130 or NASA DC-8) configured with in situ and remote gas, aerosol, liquid and ice characterization instruments to sample inflow region, mid-troposphere, and locate downwind plumes |
Ground based facilities:
To measure winds, hydrometeors, lightning characteristics, thermodynamics, and species profiles and utilize (existing) ground based networks to sample in diverse precipitation, lightning and background chemistry regimes: |
Northeast Colorado
Operated by Colorado State University
- CSU-CHILL Radar
- Pawnee national radar facilities
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Central Oklahoma
Surface facilities maintained by the National Severe Strom Laboratory & University of Oklahoma
- SMART-Rs C-Band
- KOUN polarimetric radar
- Oklahoma Lightning Mapping Array
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 Northern Alabama
Facilities operated by the University of Alabama-Huntsville & NASA Marshall Space Flight Center
- ARMOR polarimetric radar
- MAX X-band radar
- Northern Alabama lightning mapping array
- MIPS moblile sounding facility
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Forecasting:
Forecasting for DC3 operations will be accomplished through the use of guidance from both operational
and research numerical models. |
Satellite Data:
Satellite Data will be used to examine the influence of convection on the UTLS composition
and chemistry. These spaceborne data will be used before the DC3 field deployment to better prepare for
the operating period. |
Post-Mission Numerical Modeling & Analysis:
Post-mission modeling efforts will include cloud-resolving numerical models and model that utilize
parameterized convection (e.g., regional models). |
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Meetings
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Documents
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