HIRDLS HNO3 Version 2'04'09 Doug Kinnison, John Gille, Rashid Khosravi, Cora Randall, Lynn Harvey, e

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HIRDLS HNO3Version 2.04.09Doug Kinnison, John
Gille, Rashid Khosravi, Cora Randall, Lynn
Harvey, et alHIRDLS Science Team

• January 30, 2008

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Outline

• Signal characteristics
• Vertical resolution
• Measured Precision
• Accuracy (relative to Aura MLS)
• Accuracy (relative to ACE-FTS)
• HNO3 in the UTLS region.

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HIRDLS HNO3 Pre-launch Signal Characteristics
Edwards et al., Appl. Optics, 1995.
HNO3 has a strong radiance signal in channel 8
between 861-903 cm-1 With minor interferences
from CFC-11,12 and H2O, Aerosol
Limb Radiance Spectra for HIRDLS channels 6-9 for
a Tangent Height of 25km
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HNO3 Channel 8 Radiance Signal is Strong!

• Atmospheric radiances from HIRDLS Channels span
  4 orders of magnitude.
• Initial success for T and O3 was for channels
  with largest radiances, most tolerant to
  correction errors.

T
CH4
H2O
HNO3
Aerosol
O3
ClONO2
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HNO3 Validation - Estimate of Vertical Resolution
Green Line Averaging Kernels Red Line Is the
integrated area under each kernel.
Blue Line Vertical resolution as derived from
the FWHM of each averaging kernel.
Courtesy of Rashid Khosravi
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HNO3 Validation - Estimate of Precision (measured)
V2.04.09
Region of low atmospheric variability.
Courtesy of Cora Randall
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HNO3 Validation - Estimate of Accuracy (relative
to MLS)
MLS
HIRDLS-MLS/MLS
HIRDLS
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Latitude-height cross sections for HIRDLS and MLS
HNO3. The results in this figure are a zonal mean
average of 27 days (in March 2007).
V2.04.09
Courtesy of V. Lynn Harvey
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HNO3 Validation - Estimate of Accuracy (relative
to MLS)
Latitude-height cross sections of HIRDLS-MLS
coincidences for two different HIRDLS scan
tables. The left column is for scan table 13 the
right column is for scan table 23. There are
165,513 and 67, 595 coincidence used to create
the panels for scan table 13 and 23 respectively.
V2.04.09
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HNO3 Validation - Estimate of Accuracy (relative
to ACE-FTS)
V2.04.09
Latitude-longitude cross sections of HIRDLS (red)
and ACE-FTS (blue) measurement locations.
Coincidences are defined as occurring within
2-hours in time and 500 km. The coincidences show
hear are for scan table 23. There were 150
coincidences between 19 May 2006 an 31 October
2006.
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HNO3 Validation - Estimate of Accuracy (relative
to ACE-FTS)
Profile differences of HIRDLS and ACE-FTS for
Scan Table 23.
V2.04.09
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UTLS Region - comparison with Houston AVE Campaign
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UTLS Region - comparison with Houston AVE Campaign

• Agreement is good between 100-70hPa.
• HIRDLS does not completely resolve the HNO3
  filament measured by CIMS.
• Meteorological analysis suggests there is large
  horizontal and temporal variability in 15 km
  region. Therefore it is very likely that HIRDLS
  is not measuring the same air mass as CIMS.

V2.04.09
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Characterizing Filaments in the UTLS region
Descending orbit segment on March 10th 2006
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Characterizing Filaments in the UTLS region
Latitude height comparison of NCEP GFS and HIRDLS
O3 and HNO3 data products. White lines are
horizontal wind contours. Black line is 2 PV
contour. Dashed Black Line is tropopause
height. Blue dashed line is the 400 K contour.
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Summary

• HIRDLS Instrument obtains 5000-7000 HNO3 profiles
  per day!
• HIRDLS profiles are generally good over the
  latitude range of 64?S-80?N and pressure range
  of 100-10hPa, with some profiles, depending on
  latitude having useful information between
  100-161 hPa.
• The Individual profile measured precision is
  between 10-15, but can be much higher if the
  HNO3 abundance is low or outside the 100-10hPa
  range.
• HIRDLS HNO3 is biased 0-15 low relative to Aura
  MLS and 0-30 low relative to ACE-FTS.

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Future Science

• Characterize the seasonal magnitude and
  variability of HNO3 in the UTLS region. Will
  compare to available aircraft data and model
  climatology.
• HIRDLS HNO3 data will be useful in characterizing
  transport processes (e.g., filaments) in the
  mid-to-high latitude UTLS region.

Kinnison, Gille, Barnett, Randall, Harvey,
Lambert, Khosaravi, et al., accepted, JGR,
Global observations of HNO3 from HIRDLS - First
Results