L Tallis, K Shine, T Gardiner, M Coleman

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L Tallis, K Shine, T Gardiner, M Coleman

description

Assessment of the consistency of near infrared water vapour line intensities in recent HITRAN databases using ground based FTIR spectrometer measurements of solar radiation. L Tallis, K Shine, T Gardiner, M Coleman. Analysis Method. In a similar way to Casanova, et al. (2006) - PowerPoint PPT Presentation

Transcript of L Tallis, K Shine, T Gardiner, M Coleman

Page 1: L Tallis, K Shine, T Gardiner, M Coleman

L Tallis, K Shine, T Gardiner, M Coleman

Page 2: L Tallis, K Shine, T Gardiner, M Coleman

Analysis MethodIn a similar way to Casanova, et al. (2006)Optical depth spectrum given by

Where Fm is the measured signal by the FTIR, Fs is the extraterestrial irradiance given by Kurucz (1995), τm is the optical

depth, θ is the solar zenith angle and k(v) is an unknown calibration factor.

Rearrangement, ignoring the calibration factor

Page 3: L Tallis, K Shine, T Gardiner, M Coleman

FitOptical depth is calculated for water vapour

(τw) and for five other principle absorbers in the region: CH4, CO2, O2, N2O and O3 (τg) using RFM

Linear fit of the “pseudo” optical depth to that calculated by RFM

Fit pseudo to the form of a x τw + τg + b

Page 4: L Tallis, K Shine, T Gardiner, M Coleman

Fit

Page 5: L Tallis, K Shine, T Gardiner, M Coleman

Retrieved “a” parameter

Page 6: L Tallis, K Shine, T Gardiner, M Coleman

Retrieved “a” parameter

Average a1.033

2Average a 3000 cm-1 – 8000 cm-1

0.9823

Average a 8000 cm-1 – 9500 cm-1

1.1614

Average a 10000 cm-1 - 11500 cm-1

0.9560

InSb / CaF2 Setup

HITRAN 2004

HITRAN 2008

Average a1.037

5Average a 3000 cm-1 – 8000 cm-1

0.9783

Average a 8000 cm-1 – 9500 cm-1

1.1579

Average a 10000 cm-1 - 11500 cm-1

0.9762

HITRAN 2008 / HITRAN 2004

Average a1.005

5Average a 3000 cm-1 – 8000 cm-1

0.9961

Average a 8000 cm-1 – 9500 cm-1

0.9971

Average a 10000 cm-1 - 11500 cm-1

1.0233

Page 7: L Tallis, K Shine, T Gardiner, M Coleman

Retrieved “a” parameterHITRAN 2004 HITRAN 2008

Average a Value Between

DateTime (U.T.)

Solar Zenith Angle

700cm-1 and 1400cm-1

800cm-1 and 1000cm-1

1100cm-1 and 1250cm-1

700cm-1 and 1400cm-1

800cm-1 and 1000cm-1

1100cm-1 and 1250cm-1

19 Aug 2008 1311 39 0.88 0.88

22 Aug 2008 1005 48 0.82 0.82

1200 38 0.70 0.70

1230 38 0.69 0.71 0.71 0.69 0.70 0.70

1409 44 0.66 0.66

1418 45 0.82 0.86 0.83 0.82 0.86 0.83

18 Sep 2008 080407 71 0.76 0.82 0.69 0.75 0.81 0.69

111459 50 0.81 0.86 0.81 0.81 0.85 0.81

MCT / KBr Setup