CAVIAR Meeting September 2010. ASSESSMENT OF H 2 O LINE INTENSITIES.
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Transcript of CAVIAR Meeting September 2010. ASSESSMENT OF H 2 O LINE INTENSITIES.
CAVIAR Meeting
September 2010
ASSESSMENT OF H2O LINE INTENSITIES
Assessment of H2O Line Intensities
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Assessment of H2O Line Intensities
Accepted: JMS May 2010
“….compared to HITRAN2008 …. our values are higher by about 15% for intensities…”
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HITRAN08 / Oudot
Oudot Example
Average “a” Parameter
HITRAN08 Oudot UCL3000-8000 Err 8000-9200 Err 10000-14000 Err 8000-9200 Err 8000-9200 Err
0.99 0.03 1.17 0.05 0.98 0.06 1.02 0.05 1.06 0.04
CONTINUUM DETECTION
H2O Continuum Detection
• Fit spectral lines to simulation (with no continuum)
a τw + b τg + τaero + c
• a, b, c can vary freely• τaero is obtained from handheld aerosol instrument• c is baseline shift, or continuum absorption
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H2O Continuum Detection
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H2O Continuum Detection
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H2O Continuum Detection
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H2O Continuum Detection
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H2O Continuum Detection (25 cm-1)
H2O Continuum Detection (1 cm-1)
Conclusions• H2O line intensities consistency analysis
– 8000 - 9200 cm-1 spectral region is too weak in HITRAN08 by about 20%– New linelist by Oudot gives underestimation about 3%
• Technique for continuum retrieval is currently being developed but initial results are promising– Revised calibration now available– Look for consistently across a number of days– Sensitivity tests to error in profile (e.g 1% ppmv how does retrieved continuum change)– Refine aerosol contribution
• Compare retrieved continuum to new CAVIAR laboratory measurements
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