Oxford MIPAS meeting#36
29 Jul 03
Scatter plot of MIPAS
ozone (layer between 20-40 hPa) against latitude. You can see some
unrealistically large values around 80S.
Those high values are found between 100W and 40W (see
plot which shows values betwenn
70-90S plotted against longitude), i.e. around the Antarctic peninsula.
I think that's a region of strong gravity wave activity and PSC
occurrence, so this would fit together.
I have also noticed what I think must be contamination by PSCs in the
ESA NRT data, for H2O and for O3. I've attached a couple of plots for
24th June.
Current
Extended
Species
N.MWs
Range
N.pts
Range
N.Pts
pT
7
12-68km
1965pts
9-68km
2026pts
CH4
2
12-60km
3388pts
9-68km
3630pts
H2O
3
12-60km
1900pts
9-68km
2046pts
HNO3
2
12-42km
2662pts
9-42km
2904pts
N2O
2
12-47km
1823pts
9-60km
2118pts
NO2
3
24-47km
2010pts
24-68km
2721pts
O3
3
12-60km
3466pts
9-68km
3989pts
Dear colleagues, Yesterday the MIPAS level 2 processor upgrade from version 4.57 to version 4.59 has been executed (see the product MPH field SOFTWARE_VER). The most important algorithm change is the implementation of cloud detection. The cloud detection algorithm is currently only used to reject sweeps in processing in order to improve the quality of the product retrieval, no cloud information is provided in the product data file. In the next processor upgrade a product format change will be implemented to allow reporting of cloud information. (Scientific NRT retrievals of cloud information from MIPAS data can already be obtained from Leicester University at http://www.leos.le.ac.uk/mapscore/). The second modification executed yesterday is the upgrade of relevant level 2 Auxiliary Data Files (see also the DSD of any MIPAS level 2 product). MIP_CS2_AX from 20030723 MIP_MW2_AX from 20030723 MIP_OM2_AX from 20030723 MIP_PI2_AX from 20030723 MIP_PS2_AX from 20030723 MIP_SP2_AX from 20030723 MIP_IG2_AX from 20030601 This upgrade is mainly aimed at activation of the cloud-detection algorithm, but also involves improvement of microwindows and occupation matrices (including elemination of gaps between altitude validity ranges), activation of the new spectroscopic database. These files will shortly be uploaded to the envisat web site (http://envisat.esa.int/services/auxiliary_data/mipas/) Note that two further ADF updates are foreseen for the short term (please refer to the earlier message on this subject below). Regards, ----- Forwarded by Rob Koopman/esrin/ESA on 07/24/03 10:00 AM ----- Note that the change from 4.55 to 4.57 affected only the level 1 algorithm, the level 2 algorithms themselves will be modified at the next update. A short recap of recent changes on MIPAS to support your analyses: MIPAS level 1 processor 18 March, update from version 4.55 to version 4.57 Minor algorithm changes: aliassing spike removal, NESR reporting, ADC saturation flagging Important bugfix on the handling of Fringe Count Errors The current configuration is as follows (see enviview product format help for details on these auxiliary files): MIP_CA1_AX from 20020902 MIP_CL1_AX from 20021113: This is a significant modification already discussed at the workshop, this reconfiguration takes into account line of sight calibration results by correcting the pointing by 1.7 km and affects data quality in a discontinuous manner. MIP_CS1_AX from 20021014 MIP_MW1_AX from 20020924 MIP_PS1_AX from 20020730 MIP_CO1_AX and MIP_CG1_AX: These files are updated once per week to correct for gain changes due to ice. The updates are performed to keep data quality constant. MIPAS level 2 processor: Although the version number changed on 18 March to 4.57, this is because it is a joint delivery with the level 1. No algorithm changes have been activated in that release so any data quality discontinuity that you may find between these versions would be due to propagation of level 1 changes. The current configuration is as follows (see also the DSDs in the header of any MIPAS level 2 product): MIP_CS2_AX from 20020101 MIP_IG2_AX from 20030601 MIP_MW2_AX from 20020615 MIP_OM2_AX from 20020615 MIP_PI2_AX from 20020101 MIP_PS2_AX from 20021113 MIP_SP2_AX from 20020101 On the short term, the following changes that affect data quality are foreseen: - Release of MIPAS level 2 processor version 4.59 (see sw_version field in MPH) with cloud detection as most important algorithm change - A first update of level 2 auxiliary data (to actually activate the cloud detection in the new processor, improved microwindows and occupation matrices) - An update of level 1 auxiliary data (improved non-linearity correction, spectral calibration, ILS characterisation, line-of-sight calibration) - A second update of level 2 auxiliary data (to extend the retrieval altitude range, and further modifications to improve retrieval quality). These 4 changes are expected to change (improve) data quality and you will therefore be informed of their activation. Routine production and dissemination to you will continue all the time, inevitably resulting in a quality discontinuity at each of the changes ( the first and second will be combined into a single change). After completion of all these changes (as recommended at the validation workshop) the historic comissioning phase cal/val data will be (re)processed with the final configuration to have homogeneous and continuous quality with the very latest and best configuration. These data too will be provided to the ACVT for validation. The next two steps are to use the final configuration for - release of routinely produced data to the science PI's - reprocessing of all historic data >From the start of this activity onwards, the processors and their configuration will be kept stable for long intervals to construct a homogeneous long-term dataset.
