The Microwave Temperature Profiler MTP

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The Microwave Temperature Profiler (MTP) on
START-08
MJ Mahoney - JPL/Caltech Julie Haggerty -
NCAR Jan 9, 2008
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The NSF/NCAR GV Microwave Temperature Profiler
(MTP)
Top View
Scan Mirror
Frequency Synthesizer
Cal Target
StepMotor
Radiometer
Bottom View
Controller Board
DC Power Supplies
HDPE Window
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The Molecular Oxygen Absorption Spectrum (0-20 km)
Molecular oxygen absorption is the result of 44
rotational spectral lines from 50 to 835 GHz 37
lines are in the 60 GHz band. Below 10 km the
lines are heavily pressure-broadened and line
shape is not important. Above 10 km line shape
starts to matter.
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MTP Measurements Technique
In the R-J limit the oxygen emission from a thin
layer (dr) is proportional to the temperature
times the absorption coefficient times the layer
thickness attenuated by the intervening
absorption
where W(r) is the weighting function. If the
absorption coefficient is nearly constant and the
temperature changes proportional to range (r)
then
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MTP Performance During CRAVE
Above The overall MTP performance relative to
flight level for 23 comparisons with Ticosondes
(1-sigma error bars are shown). Left Examples of
two MTP retrievals (pink) compared to Ticosondes
(white).
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Data Products - Temperature Profile
An Altitude Temperature Profile (ATP) from the
NASA DC-8 MTP. The yellow dots are the retrieved
temperatures, the horizonal yellow line is the
aircraft altitude and the horizontal dashed line
is the tropopause altitude. Other information is
also shown.
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Data Products - Temperature Curtain

• CTC for DC-8 TOTE-VOTE transit flight from
  Fairbanks, Alaska to Hawaii
• Flight level is black trace, tropopause is shown
  as white dots
• The polar jet is at 57N and the subtropical jet
  is at 33N note double trop region

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Data Products - Isentropes
ATPs can be used to identify constant theta, or
isentrope, levels -- the streamlines on which air
parcels flow. The figure above illustrates DC-8
observations of a dramatic mountain lee wave
which occurred over the Norwegian Mountains on
January 25, 2000 during the first SOLVE campaign.
The green area shows the terrain cross-section,
while the black traces show MTP isentropes and
the blue trace the DC-8 flight altitude.

• .

A. Dornbrack et al. , Evidence for
inertia-gravity waves forming polar stratospheric
clouds over Scandinavia, J. Geophys. Res.,
107(D20), 8287, doi10.1029/2001JD000452, 2002.