Oxford MIPAS meeting#31
13 May Apr 03

Present

Oxford: Alastair Burgess, Anu Dudhia, Vivienne Payne
RAL: Victoria Jay, Martin Juckes, Jolyon Reburn

Instrument Status [Prev] [Next]

See Summary from Rob Koopman
Envisat mission reduced operations expected from 18-25 May 2003 during mission upgrades (details on the Envisat Web-Site)
MIPAS Special Observation Modes will be tried out in June

L2 Data [Prev] [Next]

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

Data received up until 13th May, plotted up until 25th April

L1 Data [Prev] [Next]

In /home/crun/eodg/mipas/L1B/

9 orbits from 12-24 Sep 2002 downloaded from IMK for AMIL2DA intercomparisons

MIP_NL__1PNPDK200209*

Auxiliary Data Updates (AD) [Prev] [Next]

New data in /home/crun/eodg/mipas

/OM/ Occupation Matrices
- /6km MWs for retrievals to 6km altitude selected earlier (20 Sep 2003, Summary), now OMs, error analyses and cloud-contaminated OMs added

Data Assimilation (MJ) [Prev] [Next]

Comparing MIPAS O3 with RAL GOME and SAGE III data using isentropic data assimilation scheme

Now received data until the end of March.
Running model at 1deg latitude - not much difference from 2deg model, although 2deg was significantly different from 4deg (as expected since profile spacing is also about 4deg)
Possibly look at using data assimilation for AMIL2DA MIPAS-GOMOS O3 and H2O comparisons?

REC Analysis (VP) [Prev] [Next]

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.

[Day] and [Ngt] (different colours for different altitudes, although not shown in key)
No clear evidence of any residual H2O signature, but signal may be confused by including many microwindows with weak H2O features

SF6 Retrievals (AB) [Next]

SF6 retrievals using OPTIMO

Using cross-section tabulation rather than HITRAN line data since this seems more comprehensive, and tabulation exists for a suitable range of atmospheric conditions down to 3mb pressure
Main SF6 feature (Q branch) at 948cm-1 sits on side of CO2 line and close to H2O line, so line modelling and H2O retrievals expected to be significant systematic error components
Retrieval up to 30km seems possible, but with suspicious peak observed at upper level
Weak signal, so investigating co-adding spectra to establish vertical profile

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)

First attempt at simulated 2D H2O retrieval from observations with "S6" special mode (although at 0.025cm-1 resolution), single microwindow.
Each iteration takes about 1 hour of CPU!

AMIL2DA (AD/VP) [Prev] [Next]

As part of the AMIL2DA project, IMK have selected the following SCIAMACHY and GOMOS profiles for comparison with MIPAS (email from Mathias Milz, 9 May 2003)

For SCIAMACHY we selected seven collocations from september  (20, 23,24 
september) with a maximum mismatch of 500 km. :

orbit   scan (imk-no.)   mean lat.  mean long.     crossing time (UTC)
2910      31               -43.056            0.305        20092002T095842
2911      29               -33.654        -22.535        20092002T113635
2952      29               -38.347          25.212        23092002T082229
2953      32               -47.735          -2.399        23092002T100547
2953      36               -67.595          -6.113        23092002T101121
2970      34               -38.362        -67.483        24092002T143315
2973      44               -67.598      -149.104        24092002T194319

Parameters to compare: O3 and NO2.


For GOMOS we selected 11 collocations from september  (20, 23,24 september) with 
a maximum mismatch of  5deg lat and 10 deg long :
orbit   scan)   mean lat.  mean long.     crossing time (UTC)
2911   48     -53.042      157.157        20092002T120255 TEM  O3  NO2
2911   49     -48.263      155.464        20092002T120416 TEM  O3  NO2  H2O
2912   53     -33.581      128.710        20092002T134855 TEM  O3  NO2  H2O
2915   56     -53.643        56.785        20092002T184509 TEM  O3  NO2
2915   57     -48.867        55.063        20092002T184630 TEM  O3  NO2
2915   59     -38.357        54.675        20092002T184922 TEM  O3  NO2  H2O
2915   60     -33.570        53.255        20092002T185043 TEM  O3  NO2  H2O
2952   47     -53.044     -153.978       23092002T084728 TEM  O3  NO2
2952   48     -48.266     -155.670       23092002T084849 TEM  O3  NO2  H2O
2952   50     -38.370     -155.853       23092002T085131 TEM  O3  NO2  H2O
2952   51     -33.582     -157.274       23092002T085252 TEM  O3  NO2  H2O

Parameters to compare: O3, NO2, H2O and Temperature


From Rob.Koopman@esa.int Tue May 13 11:56:20 2003

...

A brief MIPAS update:
Although since 26 March the slide velocity differences have not exceeded the
duration that triggers the intervention by the on-board monitoring system,
brief episodes of significant differences have still been detected
occasionally and data collection for analysis of these transient values has
begun, in order to complement the ongoing analysis of the events that lead to
instrument switch off.
Monitoring of cooler behaviour is now performed semi-operationally.
A dedicated non-linearity calibration (IF16+IF4+IF16) has been performed
successfully and part of the data have already become available.
A further Field-of-View calibration has been planned using Mercury on 16 May,
and the first Special Modes and Upper Atmosphere mode tests are planned for
early June (Marta De Laurentis will provide you with the details).
The operational level 1B processor version 4.57 has been activated on 18
March, and the update of the level2 processor is nearing completion.

...

Summary of MW selection for retrievals to 6km (20 Sep 2002)

CH4: 
Original selection (12-60km) - 3388pts
  1 CH4_0012 1227.175 1230.175 12 60  
  2 CH4_0001 1350.875 1353.875 12 60  
New selection (6-60km) - 3630pts
  1 CH4_0012 1227.175 1230.175  6 60  
  2 CH4_0001 1350.875 1353.875 12 60  
Same microwindows, but with CH4_0012 extended down to 6km.

H2O:
Original selection (12-60km) - 1900pts
  1 H2O_0001 1650.025 1653.025 15 60  
  2 H2O_0002  807.850  808.450 12 18  
  3 H2O_0007 1645.525 1646.200 27 60  
New selection (6-60km) - 2140pts
  1 H2O_0001 1650.025 1653.025 15 60  
  2 H2O_0022  946.650  947.700  6 18  
  3 H2O_0002  807.850  808.450  9 18  
  4 H2O_0007 1645.525 1646.200 27 60  
Add H2O_0022 since none of the other microwindows extends down to 6km,
and extend H2O_0002 down to 9km.

HNO3:
Original selection (12-42km) - 2662pts
  1 HNO30006  885.100  888.100 12 42  
  2 HNO30001  876.375  879.375 12 42  
New selection (9-42km) - 2904pts
  1 HNO30006  885.100  888.100  9 42  
  2 HNO30001  876.375  879.375  9 42  
Same microwindows, both extended down to 9km. Although both microwindows
can be used for 6km the random error approaches 50% so there is not enough
signal/noise to obtain a useful retrieval at 6km.

N2O:
Original selection (12-47km) - 1823pts
  1 N2O_0001 1272.050 1275.050 12 47  
  2 N2O_0004 1256.675 1257.975 12 30  
New selection (6-47km) - 2420pts
  1 N2O_0001 1272.050 1275.050 12 47  
  2 N2O_0012 1233.275 1236.275  6 27  
Replace N2O_0004 with N2O_0012 since neither of the original MWs can be
extended down to 6km. 

NO2:
Original selection (24-47km) - 2010pts
  1 NO2_0001 1607.275 1610.275 24 47  
  2 NO2_0003 1613.725 1616.600 24 47  
  3 NO2_0013 1622.550 1623.475 24 30  
No change since lowest altitude 24km limited by signal/noise

O3:
Original selection (12-60km) - 3466pts
  1 O3__0021  763.375  766.375 12 60  
  2 O3__0013 1039.375 1040.325 52 60  
  3 O3__0001 1122.800 1125.800 12 60  
New selection (6-60km) - 3950pts
  1 O3__0021  763.375  766.375  6 60  
  2 O3__0001 1122.800 1125.800  6 60  
  3 O3__0013 1039.375 1040.325 52 60  
Same microwindows but with O3__0021 and O3__0001 extended down to 6km, 
which also moves O3__0001 above O3__0013 in the selection sequence.

PT:
Original selection (12-68km) - 1965pts
  1 PT__0001  686.400  689.400 30 68  
  2 PT__0004  728.300  729.125 15 27  
  3 PT__0037  694.800  695.100 27 36  
  4 PT__0038  700.475  701.000 21 30  
  5 PT__0039  685.700  685.825 33 47  
  6 PT__0002  791.375  792.875 12 33  
  7 PT__0006  741.975  742.250 15 24  
New selection (6-68km) - 2749pts
  1 PT__0001  686.400  689.400 30 68  
  2 PT__0002  791.375  792.875  6 33  
  3 PT__0017  696.200  698.375 27 68  
  4 PT__0037  694.800  695.100 27 36  
  5 PT__0039  685.700  685.825 33 47  
  6 PT__0038  700.475  701.000 21 30  
Replaces PT__0004 and PT__0006 with much larger microwindow PT__0017.
However, the only information below 12km comes from PT__0002 
so it seems preferable to use the original selection with PT__0002 extended 
down to 6km since this has fewer measurements: 2087pts
Alternative new selection (6-68km) - 2087pts
  1 PT__0001  686.400  689.400 30 68  
  2 PT__0004  728.300  729.125 15 27  
  3 PT__0037  694.800  695.100 27 36  
  4 PT__0038  700.475  701.000 21 30  
  5 PT__0039  685.700  685.825 33 47  
  6 PT__0002  791.375  792.875  6 33  
  7 PT__0006  741.975  742.250 15 24  
-------------

Oxford MIPAS meeting#31 13 May Apr 03

Oxford MIPAS meeting#31
13 May Apr 03