Science Applications for UAS: Where do we want to be in 10 years

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Science Applications for UAS Where do we want to
be in 10 years? The DOE ARM Perspective Greg
McFarquhar, University of Illinois Chief
Scientist DOE ARM Aerial Vehicle Program
(AVP) Civilian Applications of Unmanned Aircraft
Systems 2 Oct. 2007
http//www.atmos.uiuc.edu/mcfarq/aavp.whitepapero
verview.pdf
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Outline

• Past Efforts of ARM Airborne Science
• Current Goals for ARM Airborne Science
• Why UAS appropriate for these goals
• Science Questions we hope to address with UAS in
  next 10 years

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Past ARM Airborne Science ARM UAV Program

• The ARM-UAV Program was established by DOE to
• address the largest source of uncertainty in
  global warming
• the interaction of clouds and solar/thermal
  energy
• support the climate change community with
  valuable data sets
• develop measurement techniques and instruments
  suitable for use with the new class of high
  altitude, long endurance UAS
• demonstrate these instruments and measurement
  techniques in field measurement campaigns

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ARM-UAV conducted 12 major field campaigns
GA-ASI GNAT 750 (F93, S94)

• Field Campaigns to date
• Fall 1993, Edwards AFB, CA
• Spring 1994, Northern OK
• Fall 1995, Northern OK
• Spring 1996, Northern OK
• Fall 1996, Northern OK
• Fall 1997, Northern OK
• Spring 1999, PMRF Kauai, HI
• Summer 1999, Monterey, CA
• Winter 2000, Northern OK
• Fall 2002, Northern OK
• Fall 2004, North Slope, AK
• Winter 2006, Darwin, Australia

Grob Egrett (F95, S96)
GA-ASI Altus I (F96, F97)
GA-ASI Altus II (Su99)
Twin Otter (F93, S94, F95, S96, F96, F97, Sp99,
Su99, W00)
Proteus(F04, W06)
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ARM Airborne Science Refocused in 2006

• To maximize science return from program
• ARM UAV had reached mature state
• Need to transition to a program that took
  advantage of instrument/technique development to
  make an impact on science
• Change name to ARM Airborne Vehicle Program (AVP)
  to be consistent with current strategy of using
  both piloted unpiloted aircraft
• AVP refocused to make observations during not
  only 1-month long IOPs, but also to make them
  routinely over long time periods to get
  representative statistics on clouds needed for
  climate models

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ARM AVP is 3-Prong Program

• Routine observations of clouds, aerosols,
  radiative other atmospheric properties
• Participation in IOPs designed to contribute to
  our fundamental understanding of clouds,
  radiation and aerosols and their effects on
  global change
• Foster instrument incubator program where
  miniaturized in-situ and remote sensing
  instruments will be purchased or developed,
• small size and modularity of instruments will
  make them amenable to UAVs and larger aircraft

Both piloted unpiloted platforms will be used
for these activities depending on platform
suitability and availability
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What is role of UAS in AVP?

• UAS play central role in future AVP activities
  because they offer unique capabilities for
  acquisition of routine observations for IOPs
• Features of UAS helpful to ARM science
• Long endurance flights
• Routine or continual flights
• Flights in under sampled regions
• Close stacking of UAS at multiple levels
• Envision need for both slow/low and high
  flying/long duration platforms

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Long duration capability of UAS is requirement
for many science goals

• Limited duration of piloted aircraft prevents us
  from measuring single cloud systems at all
  evolution stages (growth, mature, dissipating)
• Long endurance UAS (e.g., 24 hours) will let us
  track and observe cloud systems over complete
  life time
• Help us understand physical mechanisms at work
• Provide data for parameterization development

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• UAS provide observations at unique scales not
  provided by other platforms
• Satellite observations poor temporal but good
  spatial coverage
• Ground observations good temporal but poor
  spatial coverage
• Routine aircraft observations offer critical
  missing link for determining how atmospheric
  properties vary over multiple scales
• Scaling in one region may not apply to that in
  another region, so need observations in multiple
  locations

CLASIC MAS data
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UAS can make routine transects over oceans/land

• How do cloud properties vary as function of SST?
• Many recent hypotheses (Thermostat, Iris) need
  observations for evaluation
• If we could routinely fly across equator we could
  build up a large routine statistical data base
  that we could use to evaluate such hypothesis

Cloud fraction varies with SST
Hartmann and Michelsen 2002
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UAS can make routine transects over oceans/land

• How do cloud properties vary with aerosol optical
  depth?
• Large uncertainty in IPCC reports is aerosol
  indirect forcingneed observations in wide range
  of meteorological conditions to understand
• Routine transects over land could determine how
  cloud/radiative properties vary with aerosols in
  different meteorological conditions

Aerosol forcing varies depending on
meteorological conditions
Wang and McFarquhar 2007
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UAS Routine Observations Help Develop Retrievals
IWP
Optical depth
Comstock et al.
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UAS Routine Observations Help Develop Retrievals
Routine observations could identify under what
conditions differing retrievals work
IWP
Optical depth
Comstock et al.
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Slow low flying UAS can aid carbon science

• Slower and lower flying platforms flying
  routinely over a variety of surfaces could help
  examine surface flux exchanges investigating
  sources and sinks of CO2
• Similar questions could be raised for surface
  fluxes of other important trace gases

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Locations of Past Ice Cloud Measurements
Observations in data sparse regions
Heymsfield and McFarquhar 2002, Cirrus
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Observations in data sparse regions

• UAS observations in sparse data regimes will help
  understand weather/climate
• Pristine oceans in southern hemisphere
• Impacts of aerosols on Arctic climate
• Observations over equator to understand ENSO
• Ideally in combination with a ground-based mobile
  facility
• Availability of routine UAS flights could help us
  address these issues

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UAS Routine Observations give PDFs

• Critical need for assessing sub-grid variability
  in grid box representative of a climate model
  (100 km)
• Parameterizations increasingly developed to
  predict PDFs, but few observations to evaluate
  them
• More routine aircraft observations could provide
  info on this sub-grid variability

Turner et al. 2005 CWG/IRF
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Stacked Flights of UAS

• Help determine radiative heating profiles in the
  atmosphere
• Help get information on vertical profile of cloud
  properties
• Critical for 3-d radiative transfer

Ramanathan et al. 2006 Maldives
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Summary

• Multiple science questions can be addressed with
  UAS
• ARM AVP will continue to explore use of UAS to
  accomplish the science goals of ARM airborne
  science
• ARM AVP will continue to explore development of
  instrumentation for UAS relevant to needs of ARM
  science goals
• Examples of other science issues that could be
  addressed in white paper http//www.atmos.uiuc.ed
  u/mcfarq/aavp.whitepaperoverview.pdf

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Major Accomplishments of ARM UAV

• Used piloted unpiloted aircraft for
• First science flight using UAV (1993)
• Stacked flight of UAV piloted aircraft for
  cloud solar absorption measurements (1995)
• Use of unescorted UAV in general flight space
  (1996)
• 26 hour flight of UAV over SGP (1996)
• Compact instruments for UAVs used (1990s/2000s)
• Instruments payload operated from ground
• Collected data for enhanced understanding of
  clouds/aerosols/ radiation in global change (2002
  SGP IOP, M-PACE 2004, TWP-ICE 2006)