Oxford MIPAS meeting#32
27 May Apr 03

Present

Instrument Status [Prev] [Next]

L2 Data [Prev] [Next]
In /home/crun/eodg/mipas/L2/ [Plots of profile locations]

L1 Data [Prev] [Next]
All MIPAS L1B will be archived at the BADC

Auxiliary Data Updates (AD) [Prev] [Next]
New data in /home/crun/eodg/mipas

Data Assimilation (MJ) [Prev] [Next]
(MJ) Comparing MIPAS O3 with HALOE, SAGE III and RAL GOME (profile) data using isentropic data assimilation scheme. So far just 850K surface (approx 10mb or 30km).
Note that there was little MIPAS low-latitude (max O3) data in February so the February statistics should be regarded as unreliable.

REC Analysis (VP/AD) [Prev] [Next]
(VP) Performing full spectrum REC analysis in 10cm-1 wide "microwindows" for mid-lat day and night profiles in orbit 2081. Use retrieved profiles to model full spectrum (with RFM) and compare with MIPAS apodised spectra.
(AD) Monthly mean REC analyses, March data is split MAR_A (up to 15th) and MAR_B (19th onwards) either side of the L1B processor upgrade
Target species plots Nov02-Apr03 show fit of residual signatures for each species as function of altitude, converted to delta concentration, positive indicating more in atmospheric spectrum than modelled in retrieval. Pairs of dotted lines indicated +/- 10%, +/- 100% of mid-latitude day-time concentration, dashed lines indicate +/- climatological 1sigma variability
  • Most species have positive residuals below 30km, possibly indicating an underestimate of true concentration
  • Most species show discontinuity in signature at 30km (which is the altitude cut-off for the continuum retrieval?)
  • H2O Nov/Dec data is anomalous
  • No significant differences since March processing change
Spectral derivatives plots for 0th, 1st and 2nd derivative (corresponding to possible errors in radiometric gain, spectral shift and AILS width) plotted for MAR_A (left) and MAR_B (right), each point corresponds to a single microwindow at a single tangent altitude
  • Signatures generally within expected limits (indicated by dashed lines)
  • No significant differences detected after processing change
  • 0th derivative continues to show anomalously high values in the NO2 microwindows and the PT__0002 microwindow at 12,15 km

SF6 Retrievals (AB) [Prev] [Next]
SF6 retrievals using OPTIMO
  • Currently investigating improving S/N either by
    • Averaging retrieved SF6 profiles, 'removing' (somehow) A Priori
    • Averaging L1B radiances and performing a single retrieval

RAL Retrievals (VJ) [Prev] [Next]
2D tomographic retrieval being developed particularly for use with the MIPAS "S6" special mode (0.1cm-1 resolution, 100km profile spacing). Now works with simulated data
Starting to look at normal 1D retrievals with real data again

EGS [Prev] [Next]
IMK/IAA Posters/Presentations (link supplied by Gabi Stiller)
Added to EGS round-up from Meeting#29.

L1 Gain Oscillations (VP) [Prev] [Next]
Summary: improvement expected from March 03 update but still some effect

Occupation Matrix Statistics (CP) [Prev] [Next]
Summary: March 03 update may have resolved problem of apparently more contaminant profiles than pT, but still some unidentified OMs in use. Also still losing nominal OMs between +/-20 deg latitude, possibly due to 12-18km spectra being flagged as bad.

Comparisons with ODIN/SMR [Next]
Results from Jo Urban (U.Bordeaux) received 17 May
Compared data for 19-20 and 25-26 Sep 2002 for N2O and O3 with the SMR (microwave) instrument on ODIN.
Brief summary (from Jo)
  • SMR N2O is larger than MIPAS N2O, at least in the middle stratosphere (10-50ppbv), again quite some variability with altitude.
  • For O3 the agreement is within ~30%, but with some variability in altitude. Moreover, the two dates don't show the same trend as function of altitude.