Oxford MIPAS meeting#127
30 Oct 07

Present

Instrument Status [Prev] [Next]
18-24th Passive decontamination, followed by various non-linearity characterisation tests
29th Oct: alternate rearward and sideways viewing orbits
1-10th Nov: new "standard" 10 day cycle of observations: 3 days NOM, 1 day MA, 1 day UA, 3 days NOM, 2 days off.

L1B Data (JH) [Prev] [Next]
L1B coverage maps updated to Oct 14th

L1C Software (AD) [Prev]
Oxford pre-processing software to apodise L1B spectra and extract microwindows [Web Page]

Oxford L2 Processing (AD) [Prev] [Next]
Running MORSE to retrieve our own L2 data: pT, H2O, O3, HNO3, CH4, N2O, NO2, CFC-11, CFC-12, ClONO2, N2O5 and CO (LTE assumption)
Currently processing
  • all recent data with a lag of around 1 month (2 weeks for L1B data to appear, plus 2 weeks for L2 processing).
  • Backlog of any missing data since June 1st 2007
  • All September data from previous years for comparison with this year

    MIPAS - HIRDLS Comparisons (CW) [Prev] [Next]
    [Plots] showing updated version of MIPAS (Oxford L2) v latest version of HIRDLS L2 Products (here, just for 20-60N, 28JAN05, Tem, H2O and O3)
    HIRDLS is in blue and MIPAS in red. The "error" bars and dashed lines are the standard deviation about the zonal average.
    Plan to use SD in above to determine actual precision of HIRDLS data.

    Cloud Classification (JH) [Next]
    Initial attempt to distinguish spectral features for ice and water clouds based on actual cloudy spectra classified by (climatological) temperature into obvious water and ice regimes, but cannot find a single tangent altitude where both occur. A more sophisticated approach will be required.

    Polar Mesospheric Ozone [Prev]
    MORSE MA Mode retrievals show large O3 values at 90km over the S.Pole (polar night) in June 2007 [Plot]
    • Individual [O3 VMRs] @87km show that this is a persistently retrieved feature, not just due to one or two stray retrievals
    • Also, O3 lines clearly visible in [averaged 87km spectra] for 60-90S for nighttime (blue) but not in daytime (red) (1020-1060cm-1)

    2007 Antarctic Spring (AD) [Prev] [Next]
    [Oxford retrievals] of recent MIPAS measurements are showing some unusual behaviour in the 80-90S (red lines on plots) region up to early September in the 100-10mb region (comparing column amounts above 100mb with those from 10mb surface, which generally look normal)
    • A [WMO Press Release] says that the [O3 hole] was smaller than usual this year, and [temperatures] warmer, although neither is evident from the Oxford MIPAS retrievals
    • Data for end of September shows values returning to "normal"
    • Next: run MIPAS retrievals for all available days in previous Septembers for better inter-annual comparison

    ACPD Papers [Prev] [Next]
    Papers selected from the ACPD website for discussion
    "The wintertime two-day wave in the Polar Stratosphere, Mesosphere and lower Thermosphere"
    D.J.Sandford et al. (published 16 Oct 2007, open until 11 Dec 2007)
    Introduced by LMV
    "Global distribution of mean age of stratospheric air from MIPAS SF$_6$ measurements"
    G.P.Stiller et al. (published 18 Sep 2007, open until 13 Nov 2007)
    Comments being collected by JW.
    Other MIPAS-related papers in the Open Discussion phase, which may be adopted at a future meeting
    "Retrieval of global upper tropospheric and stratospheric formaldehyde (H2CO) distributions from high-resolution MIPAS-Envisat spectra"
    T.Steck et al. (published 18 Sep 2007, open untl 13 Nov 2007)
    "MIPAS: an instrument for atmospheric and climate research"
    H.Fischer et al. (published 25.06.2007, open until 11.09.2007)