Other Research Aircraft

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Other Research Aircraft

• DC-8 (with MTP)
• ER2, WB57
• HALO (2009?)
• UK BAe-146
• Smaller jets (Learjets, Falcon, etc)
• Commercial aircraft (esp. in special programs)
• Turboprop aircraft with wind-sensing (but
  altitude limitation)
• NCAR C-130, P3s, etc.
• King Air, Merlin, etc.
• Many more ... but need a quality wind-sensing
  system

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G-V Characteristics

• Certified flight to 51,000 ft climb to 41,000 ft
  fully loaded
• Max. range near 6000 n mi (gt10,000 km)
• 12-person crew satellite comm. system
• Wind-sensing
• radome-port system with dual INS/GPS and
  differential GPS
• to be added all-weather gust system, laser
  velocimeter, higher-quality INS/GPS

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Observing Gravity Waves Using Research Aircraft

• In Situ Measurements
• Wind
• horizontal wind
• vertical wind
• turbulence characterization
• Pressure (including high-resolution for
  perturbations)
• Temperature and air density
• Fluxes
• Tracers (q, ozone, CO, aerosol conc., etc)

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Observing Gravity Waves Using Research Aircraft

• Remote Measurements
• Microwave Temperature Profiler (MTP)-2007
• Aerosol-Backscatter Lidar (HSRL)-2008
• GPS full-spectrum receiver-2008
• Future
• Cloud Radar-2009
• Remote sensing of wind
• DIAL lidar(s)

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Anticipated Accuracies
(for all, resolution is much better so changes of
perhaps 10 of these values can be measured
reliably)

• Horizontal wind 0.5 m/s
• Vertical wind lt0.5 m/s
• Temperature 0.3C
• Pressure 0.3 mb?
• MTP 1-2K, 100 m vertical

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What Capabilities Are New?

• Altitude and range (and plans for routine
  operation at UT/LS altitudes)
• High-quality wind system (with GPS corrections)
  and flux-measuring system
• Temperature profiling (soon)
• Pressure-sensing system capable of measuring
  pressure fluctuations with high resolution (via
  differential GPS and special attention to
  calibration of p measurements)

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MTP measurements from DC-8 in SOLVE (from MJ
Mahoney)
375K
15
airflow
325K
p. altitude km
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GPS Full-Spectrum Receiver

• Enables the aircraft to perform like a LEO
  satellite
• occultation soundings at locations selected for
  coverage
• ability to measure path-integral time delay in
  directions of a set of satellites, from above
  most water vapor
• potential uses in conjunction with the MTP

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GPS
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Tracers

• In addition to the basic parameters of the wave,
  it is possible to measure many tracers that are
  steady on the time scale of the wave
• water vapor
• ozone
• CO
• particle concentration
• etc.

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Pressure Measurements

• Aircraft all measure pressure and fly by
  reference to a constant pressure
• Normally, measured pressure fluctuations can't be
  distinguished from altitude changes
• GPS systems now provide a high-resolution
  reference altitude, valid (with diff. GPS) to ca.
  10 cm.
• Opportunity to measure pressure fields with high
  spatial resolution (from D-value measurements)

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Measurement Opportunity

• In a gravity wave, can measure
• fluctuations u',v',w',T',p' (and hence density')
• T profiler will provide N and H (or sounding)
• linear theory constraints these amplitudes,
  dependent on k,l,m,N,H,f
• With all measured except mvertical wavenumber,
  have highly constrained solution that provides m,
  vertical propagation, etc.

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Example (over Utah)
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Another Example
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Polarization Relations
(approx.)
Expect vertical and horizontal amplitudes to be
similar, and (for typical conditions seen in
TREX) p fluctuations to be around 0.5 mb. The
corresponding D-value changes are around 20 m,
and so are measurable with the combined
GPS/pressure system.
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Another Example
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Variance Spectrum, w
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Variance Spectrum, w
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Variance Spectrum, u
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Observing Opportunities

• Long ferry legs at UT/LS altitudes provide
  opportunities for assembling climatology.
  (Example TREX flown from Colorado, ferry legs to
  California)
• Aircraft showed good flight characteristics in
  turbulence (although experience limited)
• Above-cloud observations possible (and some will
  be accumulated routinely). Opportunity to
  characterize turbulence