Oxford MIPAS meeting#34
01 Jul 03

Present

Oxford: Alastair Burgess, Anu Dudhia, Vivienne Payne, Chiara Piccolo, Chun-hay Kom ("Steve", Vac student)
RAL: Victoria Jay, Jolyon Reburn

Instrument Status [Prev] [Next] (Some details on the Envisat Web-Site)

Comments from Rob Koopman (30Jun03):

Since March there has been an increasing occurrence of an anomalous (>1.5%) difference in interferometer mirror slide speeds, MIPAS will be forced into Heater/Refuse mode on 2nd/3rd July so that full instrument buffer data can be extracted on the next recurrence
Some time in April/May there was a jump in platform pointing of the order of 23mdeg (>1km) - should be visible in the MIPAS pressure/altitude registration?

L1 Data [Prev] [Next]

Comments from Rob Koopman (30Jun03): Still being process using 18Mar03 upgrade (v4.57) Modifications expected to non-linearity correction and microwindows for ILS calibration L1B `public' release might be in mid-July.
Note received from Manfred Birk and Georg Wagner (DLR) on non-linearity and ice-contamination corrections applied to orbit 2081 (circulated to AMIL2DA project).

L2 Data [Prev] [Next]

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

Data received up until 1st Jul, plotted up until 25th Jun.
Software version 4.57 in use since 19 Mar 2003.
Next L2 upgrade (mid-Jul?) will include cloud-detection, may include extended altitude range
ESA planning on reprocessing data since September 2002

Data Assimilation (AD/CP) [Prev] [Next]

ECMWF workshop 23-26 Jun 02

Steve Pawson (DAO, NASA/GSFC): Good agreement (+/-0.5ppmv) between MIPAS O3 and SBUV 7-9mb, Dec02, currently comparing MIPAS temperatures with those from SABER (radiometer on TIMED satellite)
Antje Dethof (ECMWF): MIPAS H2O 50% drier than ECMWF analysis at low altitude, but OK towards top of stratosphere, ECMWF O3 thought to be too low at 50mb. Note that Antje's comparisons of MIPAS T, O3 and H2O v ECMWF are included in the MIPAS Monthly Reports
Dominic Fonteyn (BIRA): MIPAS H2O lower than HALOE, Nov02-Feb03

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

MW, LUTs, irregular grids now created for 17 additional species: CFC12, CFC14, ClONO2, CFC11, HCFC22, NH3, HCN, COF2, OCS, SF6, N2O5, C2H6, HOCl, H2O2, ClO and CCL4

(AD) Occupation matrices constructed for CFC12, ClONO2, CFC11, HCFC22, NH3, COF2 and SF6 - species recommended for trials with ORM since useful accuracy appears obtainable with 2-3 microwindows - MIPAS_SM Presentation [PDF file]
(AB) Use OPTIMO to try and retrieve minor species from Orbit 2081 - AMIL2DA/MIPAS_SM Presentation [PDF file]

OPTIMO Retrievals of Major Species (VP/AB) [Prev] [Next]

Oxford retrieval code, improvements

Cloud detection: set a priori continuum to high value when clouds are detected (using single-channel detection)
Oscillations reduced by increasing correlation length in a priori covariances from 7km to 50km.
AMIL2DA Presentation [PDF file]

AMIL2DA [Prev] [Next]

EU F5 project coordinated by IMK to develop independent MIPAS retrieval algorithms (Website)

Comparisons with GOMOS and SCIAMACHY NO2 and O3 profiles show general consistency but not enough GOMOS/SCIA measurements to determine any bias
Comparisons with MIPAS/GOME O3 also generally consistent
Intercomparison paper describing different processor results for orbit 2081 needs to be updated to include new Oxford and RAL results
Project Final Report now under construction

Special Modes (AD) [Next]

Apart from the MIPAS nominal mode (17 sweeps from 68-6km in 3km or greater steps, at 0.025cm-1 resolution) there are 6 `Special Modes' due to be acquired during July, but only processed as far as Level 1B

Mode	Description	Alt. Range	Vert. Resl	Spec. Resl
S1	Polar Chem. & Dynam.	7-55 km	2 km	0.025 cm^-1
S2	Trop/Strat Exchange	5-40 km	1.5 km	0.025 cm^-1
S3	Aircraft Emissions	6-40 km	1.5 km	0.025 cm^-1
S4	Stratospheric Dynamics	8-53 km	3 km	0.1 cm^-1
S5	Diurnal Changes	15-60 km	3 km	0.025 cm^-1
S6	Upper Trop/Lower Strat	6-35 km	2 km	0.1 cm^-1

As part of the MIPAS_SM (=Special Modes) project, preliminary occupation matrices have been constructed for the 0.025cm^-1 modes using the existing microwindow databases MIPAS_SM Presentation [PDF file]

Major problems encountered if the vertical sampling is decreased to less than 3km, so mode S5 OK, S1 marginal, S2 and S3 probably give no useful information due to increased S/N (ie decreased signal associated with Jacobians for narrower retrieval spacing)

Optimising Retrieval Sequence/Combinations (CP)

Investigating which pairs of species can be most efficiently combined into a joint retrieval, and best sequence for retrieving species.

MIPAS_SM Presentation [PDF file]
Conclusions are only preliminary since a limited number of trial microwindows have been selected - this needs to be extended.

Oxford MIPAS meeting#34 01 Jul 03

Oxford MIPAS meeting#34
01 Jul 03