Oxford MIPAS meeting#58
06 Jul 04

Present

Oxford: Alastair Burgess, Anu Dudhia, Don Grainger, Vivienne Payne, Chiara Piccolo, Analia Quijano, Gareth Thomas, Payel Das & Iris Yiu (undergraduate vacation projects)
RAL: Martin Juckes

Instrument Status [Prev] [Next]

Some details on the Envisat Web-Site including Instrument Availability web-site

Unavailable since 26th March due to mechanical problems.

L2 OFL Data (AQ) [Prev] [Next]

In /home/crun/mipas/L2/2PODPA/ [Plots of profile locations]

L2 OFL (off-line) data continues to be processed, most recently filling in extra orbits for days already partly processed.
Software version 4.61 in use since 17 Mar 2004
Note that some off-line data processed using v4.59 has been removed from the ESA ftp site, although we still have it at Oxford. The web-page has been amended to show which days have only been processed with v4.59 (pink squares) compared to v4.61 (grey squares).
Yvan Orsolini recently sent an email to the MIPAS QWG requesting MIPAS data from Nov/Dec 03 (no v4.61 Off Line data, only v4.59 so far). We have sent him the NRT data since he preferred to continue using that instead of the v4.59 Off-Line data.

Reduced Resolution Microwindows (AD) [Prev] [Next]

Currently selecting final set of microwindows for all species.

IFAC have been testing out retrievals using preliminary pT and H2O microwindows and, although they have successfully processed a whole orbit (after a few changes to the L1B data) they report higher than expected chi-square values. So far the cause is unknown. [Next]

MORSE (AD) [Prev] [Next]

MIPAS retrieval code being written at Oxford for public use, funded by NERC.

A web-page is now set up: http://www.atm.ox.ac.uk/MORSE
Version 1 is now public and a tar file created containing the source code and example retrievals.

NH3 (AB) [Prev] [Next]

Preparing talk and paper on NH3 retrievals for COSPAR (18th-25th July).

Continuum (GT) [Prev] [Next]

Continuing to improve programs for extracting continuum spectra from MIPAS L2 data to investigate aerosol signatures in atmospheric continuum.

Isotopic Retrievals (VP,CP) [Prev] [Next]

Using MORSE to retrieve isotopes of O3 (CP), H2O and CH4 (VP) for comparison with ODIN/SMR data for 22Nov02 and 22Nov03.

(O3) while plots of the main isotope and minor isotope look reasonable on their own, plots of the ratio look very noisy. Should the plots show an average of the ratio or a ratio of the averages? Also some uncertainty about a factor 2 in definition of the "delta" values. [Next]
(H2O & CH4) working on processing a complete day rather than a single orbit

ODIN Comparisons (PD) [Prev] [Next]

Received IDL software from Jo Urban for reading ODIN data.

Currently working on extracting ODIN results (particularly H2O and O3) for comparison with MIPAS.
Problem that ODIN profiles appear to be on an altitude grid rather than a pressure grid, and any pressure information not obvious.

Data Assimilation (MJ) [Prev] [Next]

Running data assimilation model to compare different sounders

So far completed 6 months of analysis using NRT MIPAS data, but will redo with Off Line data before writing up as a paper.
Also extending assimilation comparisons to included GOME data.

Pressure Retrieval (AD/IY) [Next]

Student project, just started.

Investigate whether it is possible to directly retrieve tangent pressure from L1B spectra by simply taking the ratio of the average radiances in two specifically chosen microwindows (analagous to the cloud-detection).
[Plot of A band spectra for nominal tangent alts]
Aim is to find two channels whose ratio gives unique tangent pressure value independent of atmospheric profile
If it is sufficiently accurate this would be useful for people who want to directly assimilate MIPAS radiances or bypass the pT retrieval to use, for example ECMWF, temperature fields.

Oxford MIPAS meeting#58 06 Jul 04

Oxford MIPAS meeting#58
06 Jul 04