First Major Slide

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Arctic Mechanisms of Interaction Between the
Surface and the Atmosphere (AMISA)
PI Al Gasiewski1 Co-PIs Ola Persson2, Don
Cavalieri3, Markus Thorsten3, and Michael
Tjernström4 1Center for Environmental
Technology/ Univ. of Colorado, Boulder,
Colorado 2CIRES/NOAA/ESRL/PSD, Boulder, Colorado
3NASA Goddard, Greenbelt, MD 4Dept. of
Meteorology, Univ. of Stockholm, Stockholm,
Sweden

• Other participants
• V. Leuski, D. Kraft, grad student, CET at U. of
  CO
• B. Brooks, U. of Leeds, UK aerosol sampling
• E. Sukovich, CIRES - microphysics

Funding obtained from U.S. National Aeronautics
and Space Administration (NASA)
2
NASA McDonnell-Douglas DC-8-72 research aircraft
- flexible altitudes, extended range (300-14,000
m 5400 nm) - prolonged flight duration (12 hr) -
large scientific payload capability (30,000
lbs)- on-board laboratory environment
Airborne measurements over/in vicinity of R/V
Oden with in-situ and remote sensors on NASA
DC-8. Six flights during Aug 11-29, 2008. To be
based in Kiruna, Sweden
Measurements focused on A. Synoptic/mesoscale
structure of clouds, dynamics parameters, and
surface features B. Testing and validation of
satellite retrieval techniques C. In-situ
sampling of cloud microphysics, aerosol species,
and size distributions
White area sea ice extent 9/3/2007 Magenta line
median sea ice extent 1979-2000 (NSIDC)
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SCIENCE OBJECTIVES
Specific Objectives 1) in-situ validation for
ship, aircraft, satellite data 2) determine
processes linking cloud radiative/microphysical
properties to synoptic/mesoscale disturbances,
boundary-layer structure, and surface energy
budgets near freezeup 3) determine type and size
distribution of aerosols in/near high-latitude,
low-level clouds and thermal inversion 4)
aircraft/satellite sea-ice imaging/mapping and
atmospheric radiometric profiling 5)
validate/improve NASA Aqua AMSR-E sea-ice
concentration algorithm under fall transition
conditions, esp. atmospheric correction 6)
evaluate C-/L-band for lead/meltpond
discrimination
4
Instrumentation
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Instrumentation
CAPS Cloud Aerosol and Precipitation
Spectrometer
PSR on aircraft
Aerosol sampling Leeds airborne VACC
1. MetOne Condensation Particle Counter (CPC) -
total aerosol load per ml for particles R gt 3nm
Data rate 10 Hz 2. Scanning Mobility Particle
Sizer (SMPS) - give number concentration for 3
nm lt R lt 150 nm. - spectrum generated every 2.5
min 3. Volatility System. - provides
physio-chemical information about the sampled
aerosol - obtain size-segregated composition of
aerosol and estimate of population mixing state
- volatility spectrum obtained every 10 min
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Flight Tracks
Mesoscale/mid-altitude track
Synoptic, high-altitude track
Synoptic/mesoscale sampling track 1) high-level
passes (10 km) on way to Oden (black dot) and
mid-level (1 km) in vicinity of Oden 2) use
dropsondes (D) and remote sensors for mapping and
profiling Obtain 1) synoptic
thermodynamic/kinematic structure of environment
upwind and near Oden 2) integrated water CLW -
pseudo profile with up/down sfc DCR 3)
radiative flux divergence of low-level cloud tops
Low-level track liquid cloud penetration
Low-altitude transect liquid cloud
penetration Obtain 1) particle size
distributions of liquid drops/cloud ice, CLW
-CAPS 2) integrated water CLW - pseudo profile
with up/down sfc DCR 3) sub-cloud broadband
radiative flux divergence 4) detailed mapping of
surface meltponds/leads
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Key Dates May 12-13 testing dropsondes in
Palmdale, CA July 17-25 installation/integration
of sensors on DC-8, Palmdale CA Aug. 8 Transit
of DC-8 to Kiruna Aug. 11 First possible
sortie Aug. 29 Last possible DC-8 sortie

• Outstanding Issues
• Building mounting ferrings for dual-channel
  radiometers
• Building mounting ferrings for broadband
  radiometers
• Building/testing dropsondes in conjunction with
  Yankee Technology
• Finalizing CAPS probe procurement, training staff
  on system
• Finalizing/procuring aerosol inlet system
• Procuring accommodations for science staff in
  Kiruna
• Coordination logistics with R/V Oden
• (items 4,5 from ARCTAS participants?)

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• END
• SLUT
• FIN
• ENDE

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AMISA SCIENCE OBJECTIVES
3) Validate the NASA Aqua AMSR-E sea-ice
concentration retrievals under summer conditions
(pre-melt, meltponds, and freezeup) Summer
conditions are particularly difficult for the
retrieval of sea ice concentration because melt,
freeze, meltpond development greatly modify the
sea ice and snow emissivities.
From Markus and Dokken, 2002
The figure shows modeled sea ice concentration
from the NASA Team (NT) and enhanced NASA Team
(NT2) for different summer sea ice conditions.
The top and bottom figure how the atmosphere is
handled.
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AMISA SCIENCE OBJECTIVES
4) Validate the atmospheric correction portion of
the NASA Aqua AMSR-E sea-ice concentration
algorithm
The standard AMSE-E sea ice concentration
algorithm (NT2 Markus and Cavalieri, 2000)
includes an atmospheric correction scheme, which
is particularly important in the marginal sea ice
zone and during summer.
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AMISA SCIENCE OBJECTIVES
5) Develop a microwave (C-/L-band) capability for
distinguishing between meltponds and open water
areas (leads and polynyas) Meltponds are a
critical error source in the determination of sea
ice concentration. The sensitivity of water
emissivity to salinity may make it possible to
distinguish between freshwater meltponds and open
ocean areas. Although this sensitivity decreases
with decreasing temperature (see Figure). The
utilization of lower frequency channels will be
explored.
2.65 GHz
From Klein and Swift, 1977
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Map showing (a) two primary aircraft sampling
regions, and (b) sample high-level transit flight
track at 7.5 km altitude to the Oden area. In
(b), the Oden is marked by the large black dot,
transit legs are shown as black lines, and
approximate dropsonde locations marked by D.
The S marks the spiral descents or ascents. The
maps also show marginal ice zone and perennial
ice on August 17, one day after the historic mean
date of freezeup.The box near the Oden shows the
primary surface-characterization area.