Arctic Mechanisms of Interaction Between the Surface and the Atmosphere (AMISA). PI: Al Gasiewski 1 Co-PIs: Ola Persson 2 , D on Cavalieri 3 , Markus Thorsten 3 , and Michael Tjernström 4 1 Center for Environmental Technology/ Univ. of Colorado, Boulder, Colorado - PowerPoint PPT Presentation
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Landskrona, Sweden April 14-18, 2008 ASCOS Planning Meeting Arctic Mechanisms of Interaction Between the Surface and the Atmosphere (AMISA) PI: Al Gasiewski 1 Co-PIs: Ola Persson 2 , Don Cavalieri 3 , Markus Thorsten 3 , and Michael Tjernström 4 1 Center for Environmental Technology/ Univ. of Colorado, Boulder, Colorado 2 CIRES/NOAA/ESRL/PSD, Boulder, Colorado 3 NASA Goddard, Greenbelt, MD 4 Dept. of Meteorology, Univ. of Stockholm, Stockholm, Sweden Other participants: 1) V. Leuski, D. Kraft, grad student, CET at U. of CO 2) B. Brooks, U. of Leeds, UK – aerosol sampling 3) E. Sukovich, CIRES - microphysics g obtained from U.S. National Aeronautics and Space Administration
Arctic Mechanisms of Interaction Between the Surface and the Atmosphere (AMISA)
PI: Al Gasiewski1Co-PIs: Ola Persson2, Don Cavalieri3, Markus Thorsten3, and Michael
Tjernström4
1Center for Environmental Technology/ Univ. of Colorado, Boulder, Colorado2CIRES/NOAA/ESRL/PSD, Boulder, Colorado
3NASA Goddard, Greenbelt, MD4Dept. of Meteorology, Univ. of Stockholm, Stockholm, Sweden
Other participants:1) V. Leuski, D. Kraft, grad student, CET at U. of CO2) B. Brooks, U. of Leeds, UK – aerosol sampling3) E. Sukovich, CIRES - microphysics
Funding obtained from U.S. National Aeronautics and Space Administration (NASA)
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
NASA McDonnell-Douglas DC-8-72 research aircraft
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
- 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
Measurements focused onA. Synoptic/mesoscale structure of clouds, dynamics parameters, and surface featuresB. Testing and validation of satellite retrieval techniquesC. In-situ sampling of cloud microphysics, aerosol species, and size distributions
White area: sea ice extent 9/3/2007Magenta line: median sea ice extent 1979-2000 (NSIDC)
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
SCIENCE OBJECTIVES
Specific Objectives1) 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 freezeup3) determine type and size distribution of aerosols in/near high-latitude, low-level clouds and thermal inversion4) 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 correction6) evaluate C-/L-band for lead/meltpond discrimination
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
Volatile Aerosol Concentration and Composition (VACC)
University of Leeds' system Aerosol number concentration spectra and aerosol composition
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
Instrumentation
1. MetOne Condensation Particle Counter (CPC) - total aerosol load per ml for particles R > 3nm; Data rate 10 Hz2. Scanning Mobility Particle Sizer (SMPS) - give number concentration for 3 nm < R < 150 nm. - spectrum generated every 2.5 min3. 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
Aerosol sampling: Leeds airborne VACC
PSR on aircraftCAPS: Cloud Aerosol and Precipitation Spectrometer
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
Flight Tracks
Synoptic/mesoscale sampling track1) 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 Oden2) integrated water & CLW - pseudo profile with up/down & sfc DCR3) radiative flux divergence of low-level cloud tops
Synoptic, high-altitude track
Low-altitude transect & liquid cloud penetrationObtain 1) particle size distributions of liquid drops/cloud ice, CLW -CAPS2) integrated water & CLW - pseudo profile with up/down & sfc DCR3) sub-cloud broadband radiative flux divergence4) detailed mapping of surface meltponds/leads
Mesoscale/mid-altitude track
Low-level track & liquid cloud penetration
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
Key DatesMay 12-13: testing dropsondes in Palmdale, CAJuly 17-25: installation/integration of sensors on DC-8, Palmdale CAAug. 8: Transit of DC-8 to KirunaAug. 11: First possible sortieAug. 29: Last possible DC-8 sortie
Outstanding Issues1) Building mounting ferrings for dual-channel radiometers2) Building mounting ferrings for broadband radiometers3) Building/testing dropsondes in conjunction with Yankee Technology4) Finalizing CAPS probe procurement, training staff on system5) Finalizing/procuring aerosol inlet system6) Procuring accommodations for science staff in Kiruna7) Coordination logistics with R/V Oden
(items 4,5 from ARCTAS participants?)
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
ENDSLUTFIN
ENDE
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
AMISA SCIENCE OBJECTIVES3) 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.
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.
From Markus and Dokken, 2002
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
AMISA SCIENCE OBJECTIVES4) 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.
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
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.
AMISA SCIENCE OBJECTIVES
2.65 GHz
From Klein and Swift, 1977
April 14-18, 2008ASCOS Planning Meeting Landskrona, Sweden
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.
