Collaborative UTLS Research Interests at NCAR and the Use of HIAPER

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Collaborative UT/LS Research Interests at NCAR
and the Use of HIAPER

• ACD L. Pan, S. Schauffler, W. Randel, B. Ridley
• MMM M. Barth (also ACD), D. Lenschow (also ATD),
  A. Heymsfield
• ATD J. Stith, D. Rogers, T. Campos
• CGD P. Rasch

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Motivations

• Important impact - Ozone, water vapor, cirrus
  clouds, and aerosols have major effects on
  Earths radiation budget

• Complicated processes - Multiscale transport and
  exchange between LS and UT, strong gradients in
  trace constituents, and multiphase chemistry

• Common interest - critical mass of collaborators
  interested in chemistry,dynamics and microphysics
  of UT/LS

• New tools - the AURA satellite (2004) and HIAPER
  (2005)

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Dynamics, Chemistry, and Clouds in UT/LS
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Inter-related scientific issues in
UT/LS transport - chemistry - clouds

• Seasonal variations in ozone and water vapor are
  controlled by transport and chemistry

• Production and loss of ozone in this region is
  very sensitive to radicals (HOx,NOx, ROx ClOx,
  BrOx) and their precursors, which can be brought
  to UT by convective transport

• Cloud processing/tranport of chemical species and
  production of NOy by lightening link convection
  to upper tropospheric chemistry

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Scientific Issues (cont.)

• Multiphase chemistry associated with aerosols and
  cloud particles is not well understood

• Aerosol composition in the upper troposphere
  depend on transport history

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Integrated studies using satellite data, HIAPER,
and models

• Satellite observations provide spatial temporal
  coverage needed for global modeling efforts
• Aircraft provide observations of small-scale
  processes in targeted areas
• New models can provide powerful tools for
  designing observational studies and interpreting
  the measurements.

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Tropopause in the Extratropics

• Thermal tropopause derived from the Microwave
  Temperature Profiler (MTP/JPL, Gary/Mhoney) data
  (TOTE/VOTE) and PV, zonal wind fields from UKMO
  analyses

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DIAL ozone (Browell) , MTP tropopause
(Gary/Mahoney), UKMO PV
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DIAL ozone (Browell) , MTP tropopause
(Gary/Mahoney), UKMO zonal wind
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Model (CLaMS) Investigation of SONEX flight 10
L. Pan et al., work in progress
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A Mixing Layer Revealed by Tracer Correlation

• ER-2 measurements across the extratropical
  tropopause in two latitudinal locations
• Colors indicate the data points are above (red)
  or below(green) the thermal tropopause
• The characteristics of the mixing layers are
  different at the two latitudinal locations,
  showing the influence of the subtropical jet.

L. Pan work in progress
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Figure 1, Schematic of the convective injection
of peroxides and the cycling of HOy in the upper
troposphere Cohan et al., 1999.
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Net ozone production (24 hour average) as a
function of NOx above 8 km. Blue pluses are
steady state point model calculations and red
solid circles are steady state observed
calculations. The three curves show model
calculations for average conditions during
SUCCESS at 11 km, assuming different levels of
HOx source. The dashed line assumes the
peroxides and formaldehyde to be at steady state,
the dotted line uses the same steady state
assumption but does not include production of HOx
from acetone photolysis, and the solid line
assumes a convective source of peroxides and
formaldehyde with acetone photolysis Jaegle et
al., 1998.
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SUBVISUAL CIRRUS
Heymsfield (1986)
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Monsoon circulation and STE
(Dethof et al. 1999)
Randel et al., JGR 2001
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Satellite Platforms - AURA/HIRDLS

• The AURA satellite is scheduled to be launched in
  2004 for a nominal mission of five years. Four
  instruments on board are HIRDLS, MLS, OMI, and
  TES.

• HIRDLS (NCAR/ACD involved) observes global
  distribution of temperature and concentrations of
  O3, H2O, CH4, N2O, NO2, HNO3, N2O5, CFC-11,
  CFC-12, ClONO2, and aerosols in the upper
  troposphere, stratosphere, and mesosphere.

• High resolution measurements (vertical 1 km and
  horizontal 4x5 Lat-Lon).

• HIAPER campaigns in UT/LS regions, in addition to
  the defined scientific objectives, may also
  contribute to AURA/HIRDLS validation.

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HIAPER - an ideal platform for UT/LS studies

• High altitude capability that is ideal for mid
  latitude UT/LS studies
• Long flight duration for broad spatial coverage
  in the tropopause region
• Capacity for reasonable sized chemistry/tracer/aer
  sol/radiation instrument complement
• Possibility of having significant remote sensing
  capability onboard

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HIAPER measurements that can contribute to the
UT/LS studies

• Meteorological parameters temperature and
  temperature profiles, pressure, winds,
• In situ and Remote sensing measurement of
  chemical tracers O3, H2O (total water and
  isotopes) , CO, CH4, N2O, CO2, halocarbons
• Ozone photochemistry NOy, species contributing
  to NOy, HOx, RO2, CH2O, peroxides, hydrocarbons,
  photolysis rates,

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HIAPER measurements (cont.)

• Cloud and aerosols Aerosol and hydrometeor size
  distributions, condensed water content,
  extinction coefficient, asymmetry parameter, CCN,
  aerosol compositions
• Sampling rates for small-scale processes - 25 per
  second for mean structure-2 per second
• onboard calculation and display of variables to
  facilitate flight planning

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Collaborative UT/LS Research at NCAR

• To identify key scientific issues in UT/LS
  research and to define our primary objectives (in
  progress)
• To design an infrastructure to implement a
  collaborative effort
• To plan HIAPER campaigns for the defined UT/LS
  scientific objectives in conjunction with
  university and other collaborators.