1. MIPAS Monitoring at Oxford
Anu Dudhia, Alastair Burgess, Chiara Piccolo & Vivienne Payne
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2. MIPAS Monitoring at Oxford
Daily Means
Monthly Means
Occupation Matrix Statistics (monthly)
REC Analyses (monthly)
Results on web
and selected results provided for monthly reports
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3. Daily Mean Plots
BIRA reported depressed CH4 values following Envisat switch-on 7th Sep 03
indicated a need for day-by-day monitoring
Started generating daily zonal mean plots of NRT data at Oxford from 22nd Sep 03
Key findings
3-day pointing oscillation
Change in HNO3 following LUT upgrade
Step change in concentrations Nov 4th 03
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7. Monthly Mean Plots Main aims are: Key Findings
Monitoring monthly changes in mean value
Comparison with climatology
Comparison of latitude structure
Check for (un)expected diurnal variability
Check on scatter about mean
Key Findings
Tangent altitudes generally up to 1km higher than nominal
Persistent equatorial anomaly at 12/15km CH4, N2O
Most retrievals are within 10% of climatology
Not much change compared to 12 months ago
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18. Occupation Matrix Statistics
Main aims are to monitor:
L2 NRT profile count
Latitude distribution of retrievals
Frequency of corrupt bands
Frequency of cloud detection
Key Findings
Missing S.Polar data Jan 2003 (due to fringe count error)
L2 file format bug with profile counter (fixed in v3.57 but not in 3.59)
Unidentified OMs (due to altitude bands being too narrow and accidental use of old OM data at ESRIN in May03)
Decreasing frequency of cloudy OMs in October 2003
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19. Nov 02

20. Nov 03

21. REC Analysis Main aims are to monitor: Key Findings Additional Work
Residuals of key species
Residuals of error sources
Spectral derivative signatures
Key Findings
Spectral shift with wavelength
Possible underestimate of AILS width
Problems with NO2 microwindows
Additional Work
Oxford ‘OPTIMO’ retrieval of OCS
Check Spectral Calibration including D Band
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32. REC Analysis Extended Into The D Band
Zeroth (Gain)
Non-Operational Microwindows:
[PT, H2O], NH3, OCS, SF6, SO2

33. First (Shift)
No spectral calibration applied. These residuals originate with OPTIMO.
A Linear Trend?

34. Second (Spread)

35. Conclusions Results stable with time Specific points
Problems with NO2 microwindows?
Persistent equatorial anomaly at 12/15km CH4, N2O
Decrease of a few percent in trace gases since 3rd November 2003
Increase in HNO3 of the order of 10% since 23rd July 2003
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