Oxford MIPAS meeting#26
04 Mar 03

Present

Oxford: Alastair Burgess, Anu Dudhia, Don Grainger, Francesco Lama, Clive Rodgers
RAL: Victoria Jay, Martin Juckes, Jolyon Reburn

Instrument Status [Prev] [Next]

Envisat switched off 07:27 20 Feb (Orbit 5099) due to `a communication problem affecting the command queue', although MIPAS itself had switched off earlier for an unspecified reason at 00:13 (Orbit 5094)

MIPAS back in measurement mode 13:48, 23 Feb (Orbit 5146)

Envisat Orbit Control manouevre, originally scheduled for 25 Feb, was brought forwards and performed during this interruption in operation.

L2 Data (CP) [Prev] [Next]

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

Data received up until 1st March

ESA Processing [Next]

At the MIPAS Special Modes meeting the previous week Claus Zehner said that the

Plan was to have the upgraded L1 processor working from April, and L2 from July.
MIPAS Special Modes observations will also start in April

Request from Rob Koopman to the MIPAS-QWG to specify particular orbits for processing activities - email below

Software Updates (AB) [Prev] [Next]

Software in /home/crun/eodg/mipas

/optimo/ (Oxford L2 processor) recommended set of compilation flags now identified for Linux, to be listed in file README.txt

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

New data in /home/crun/eodg/mipas

/CS/, /grd/ and /MW/ (LUTs, irreg.grids and MW database)
- New LUTs etc created for HNO3 microwindows 0001, 0006, 0012 (using corrected database with missing HNO3 lines inserted)

Missing L2 Data [Prev] [Next]

Antarctic data improving throughout February
But February shows more frequent problems over the equator (eg 8th Feb L2 profile locations)
Indicated as a L1B problem by unreasonably high cloud top height plots (from Michael Hoepfner, IMK)
Problem thought to be related to fringe count error and seems to be resolved with new version of L1B software (not yet installed)

Duplicate L2 Data (MJ)

Finding occurrences of duplicate profiles - same time, similar but not identical profiles eg pT, 1st Jan 2003, 16:54:30

Data Assimilation (MJ) [Prev] [Next]

Assimilating MIPAS O3 in an isentropic model

Successfully assimilated January data
SAGE III data for January comparison not yet available
Suggested looking for POAM data (similar instrument, better polar coverage) but none available since end 2000.
Still waiting for GOME O3 profile data to be processed at RAL

Minor Species (AD/AB) [Prev] [Next]

Part of the Special Modes study is to identify additional species which can be retrieved. Progress meeting#1 held on 27Feb03 in Bologna.

AD Presentation

Earlier work prioritised species which could be retrieved with greatest absolute accuracy (p6-7),
However if we allow for the climatological uncertainty in these species a different set of priorities emerges (p8)

Also depends on assumptions about profiles used for microwindow selection, so an attempt has been made to retrieve the various species from real data: OPTIMO retrievals for all species - Orbit 2081, Scan#12 (mid-lat day), latest L1B version.

Dashed lines represent A Priori, dotted lines +/-100% uncertainty
Symbols represent retrieval, inner error bars are retrieval error, outer error bars are +/-100% A Priori uncertainty
Colours represent improvement in information compared to a priori yellow (high) - orange - red - blue (low)
Some species (eg CFC-14) which should have been retrievable apparently are not - probably due to using unrealistic profile in simulations
Other species (HOCl, ClO) probably only retrievable in polar winter (not mid-lat day)

Error Analysis (AD) [Prev] [Next]

Another part of the special modes study is to update estimates of error sources (p2-4 of AD Presentation)

Changes since original MW selection are as follows

NESR updated to use in-flight values from orbit 2081 - about 25% higher
Uncertainty in Radiometric Gain - increased from 1% to 2%
Uncertainty in AILS width - value of 2% derived from observed 2nd derivative signatures in the residual spectra during the first 6 months of operation.
Uncertainty in high-altitude column - new
SO2 Climatological variability - now reduced by factor 10.

Date: Fri, 28 Feb 2003 15:45:46 +0100
From: Rob.Koopman@esa.int
To: mipas-qwg@esoc.esa.de
Subject: historic data requirements

Dear colleagues,

A reference dataset is being defined consisting of level 0 orbits from 2002
 that will be included in future (re)processing activities.  The three ACVT
 subgroups have already formulated requirements, but I invite you to specify
 datasets that are to become part of such a reference set, and should be
 processed at every upgrade.  Please provide me with orbit numbers and a brief
 justification text explaining the selection.

Regards,
E: Rob.Koopman@esa.int

Oxford MIPAS meeting#26 04 Mar 03

Oxford MIPAS meeting#26
04 Mar 03