Ongoing projects
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Final Report of the study:
Development of an Optimised Algorithm for Routine p,T and VMR Retrieval from MIPAS Limb Emission Spectra (1995-2004)
- 0 Final_report_executive summary
- 1 Final_report
- 10.01 ATBD
- 10.02 High Level Software Architecture
- 10.03 Software architecture and
- 10.04 SVD-decompression for
- 10.05 High Level Description
- 10.06 Pre-flight modifications
- 10.07 New functionalities implemented
- 10.08 Memorandum on determination of the VCM
- 10.09 Cloud detection for MIPAS
- 10.10 Latitude dependence of MIPAS Microwindow Selection
- 10.11 MIPAS predicted retrieval
- 10.12 HITRAN error correlations
- 10.13 Spectroscopic database updates
- 10.14 MIPAS_03 an update
- 10.15 Installation and code description
- 10.16 Results of WP 8300
- 10.16 Results of WP8300 update
- 10.17 Parameterisation of the Level 0 to 1b data
- 10.18 Level 0 to 1b Data Processing
- 10.19 MIPAS-B_Flight report Flight #6
- 10.20 MIPAS-B_Flight report flight #7
- 10.21 Implementation of balloon geometry
- 10.22 MIPAS-B2 data analysis
- 10.23 MIPAS-B2 Flight 6 data analysis
- 10.24 MIPAS-B2 Flight 7 data analysis
- 10.25 MIPAS-B2 Flight 6 data analysis
- 10.26 MIPAS-B2 Flight 7 data analysis
- 10.27 Level 2 algorithm characterisation
- 10.28 ORM for Commissioning Phase
- 10.29 Description of Statistical Tool
- 10.30 ORM Cal Val analysis 1stpart
- 10.30 ORM Cal Val analysis 2ndpart
- 10.31 REC analysis of MIPAS data
- 10.32 MIPAS Occupation Matrix Statistics
- 10.33 Detection of cloud effects
- 10.34 Results of intercomparisons
- 10.35 Averaging Kernels for MIPAS NRT
- 10.36 Mapping of temperature
Auxiliary Data for a Better Characterisation of MIPAS Level 2 Products:
measurements from January 2005 on
measurements from January 2005 on
Averaging Kernels
The Averaging Kernels for the 2002-2004 measurements were computed a-priori for different standard atmospheres.
For the measurements from January 2005 on, the AKs are provided for each retrieved profile in the Level 2 products. This is possible because with the new measurements regularization is needed to reduce instability of the retrieval (the vertical sampling grid is finer than the IFOV of the instrument, and retrieval is performed in correspondence of the measurement sampling grid). In this case, the Averaging Kernels computed on the retrieval grid are not equal to the Identity matrix, as is the case when no regularization is applied, and hence the computation of the Averaging Kernel is not too much time computing.
For the measurements from January 2005 on, the AKs are provided for each retrieved profile in the Level 2 products. This is possible because with the new measurements regularization is needed to reduce instability of the retrieval (the vertical sampling grid is finer than the IFOV of the instrument, and retrieval is performed in correspondence of the measurement sampling grid). In this case, the Averaging Kernels computed on the retrieval grid are not equal to the Identity matrix, as is the case when no regularization is applied, and hence the computation of the Averaging Kernel is not too much time computing.
Systematic Errors
The systematic errors have been estimated by Oxford University and are downloadable here.
For a description of the error analysis performed by Oxford University we refer to the website: http://www.atm.ox.ac.uk/group/mipas/err/.
For a description of the error analysis performed by Oxford University we refer to the website: http://www.atm.ox.ac.uk/group/mipas/err/.
pT error propagation matrices
Still not available
MIPAS Dedicated Spectroscopic Database
A dedicated spectroscopic database for MIPAS experiment has been built starting from HITRAN96 with improvements obtained through new laboratory studies or new calculations. A first version of the MIPAS database, which is called mipas_pf2.0, includes updates for the HOCl, HNO3, O3, NO2, CH4 and H2O molecules that have been validated performing comparisons between atmospheric simulated spectra and atmospheric ATMOS spectra (see Technical Note).
A new version of the spectroscopic database, which is called mipas_pf3.1, further improves hitran_mipas_pf2.0 with new laboratory spectroscopy or new calculations (see Technical Note )
The molecules that are improved in mipas_pf3.1 are CO2, HNO3, CH4, NO2, O3 and COF2.
The database mipas_pf3.1 is being used for near real time operational Level 2 analysis of MIPAS measurements since 23 July 2003.
References
For further explanation on the MIPAS spectroscopic database, please refer to the following papers:
A new version of the spectroscopic database, which is called mipas_pf3.1, further improves hitran_mipas_pf2.0 with new laboratory spectroscopy or new calculations (see Technical Note )
The molecules that are improved in mipas_pf3.1 are CO2, HNO3, CH4, NO2, O3 and COF2.
The database mipas_pf3.1 is being used for near real time operational Level 2 analysis of MIPAS measurements since 23 July 2003.
References
For further explanation on the MIPAS spectroscopic database, please refer to the following papers:
- J.-M. Flaud, A. Perrin, J. Orphal, Qingli Kou, P.-M. Flaud, Z. Dutkiewicz and C. Piccolo, “New analysis of the u5+ u9 - u9 hot band of HNO3”, Journal of Quantitative Spectroscopy & Radiative Transfer, 77, 355-364 (2003).
- J.-M. Flaud, G. Wagner, M. Birk, C. Camy-Peyret, C. Claveau, M.R. De Backer-Barilly, A. Barbe and C. Piccolo, “The Ozone absorption around 10 mm”, Journal of GeophysicalResearch – Atmospheres, Vol. 108, No. D9, 4269 (2003).
- J.-M. Flaud, C. Piccolo, B. Carli, A. Perrin, L.H. Coudert J.-L Teffo, and L.R. Brown “Molecular line parameters for the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) experiment”, J. Atm. and Ocean Optics, 16, 172-182 (2003).
HOW TO OBTAIN A COPY OF THE DATABASE
The database is distributed only to the teams that are part of ACVT (Atmospheric Chemistry Validation Team) under the following conditions:
- The database is provided free of charge.
- The database is distributed with the implicit understanding that:
it will be used for peaceful purposes within the field of scientific research;
it will not be distributed to other partners;
it will not be used for the production of commercial products. - The authors of the database shall not be held liable for any damage and /or third party infringement that may be caused by the use of the database.
- Inconsistencies and errors identified in the database will be reported to the authors.
The scientific results obtained using the database can be published in the scientific literature provided that reference is made to the following publication: J.-M. Flaud et al., J.Atm and Ocean Opt., 16, 172-182 (2003)
Send an e-mail to This email address is being protected from spambots. You need JavaScript enabled to view it. with copy to This email address is being protected from spambots. You need JavaScript enabled to view it. and
This email address is being protected from spambots. You need JavaScript enabled to view it. in which you:
- list your name and affiliation
- state that you have read and fully accepted the above conditions.
You will receive a password with which you can download the database.
The database is expected to be distributed to a wider community after the ACVT-2 Workshop, that is planned for 3-7 May 2004 at ESA-ESRIN.
The database is expected to be distributed to a wider community after the ACVT-2 Workshop, that is planned for 3-7 May 2004 at ESA-ESRIN.
Auxiliary Data for a Better Characterisation of MIPAS Level 2 Products:
June 2002 - March 2004 measurements
June 2002 - March 2004 measurements
In order to fully characterise MIPAS products, the following additional informations are needed, other than the VCM of the retrieved profiles.
Averaging Kernels
In order to perform the comparison of measurements of the same quantity obtained from different instruments we have to take into account the different characteristics of the observing systems. The different measurements that are compared may have:
- different altitude grids
- different vertical resolutions
- different a priori information
Therefore the differences observed in the comparison are not only due to measurement errors, but also to different representations of the retrieved profiles. As a consequence the alone variance covariance matrix of the retrieved profiles does not provide a sufficient information to perform a correct comparison between independent measurements. In addition to error information it is necessary to provide a description of how the observing system modifies the true state of the atmosphere. This information is included in the averaging kernel matrix.
Click here to download the Averaging Kernel Matrices of MIPAS for Near Real Time products.
Click here to download a document describing the Averaging Kernel Matrices of MIPAS for Near Real Time products.
Click here to download the Averaging Kernel Matrices of MIPAS for Off-line products.
Click here to download a document describing the Averaging Kernel Matrices of MIPAS for Off-line products.
Click here to download the Averaging Kernel Matrices of MIPAS for the non-target species: CFC-11, ClONO2, N2O5, CFC-12.
Click here to download the profiles corresponding to the atmosphere status for which the Averaging Kernel Matrices have been calculated.
The file IG_GEO.DAT contains the altitude grid where the profiles are represented.
Four directories are provided, one for each season. In each directory the files IG_*.DAT contain the profiles for each species (specified by the file name) and each latitude band (specified within the file).
Please refer to the documents above for explanation on their use.
Click here to download the Averaging Kernel Matrices of MIPAS for Near Real Time products.
Click here to download a document describing the Averaging Kernel Matrices of MIPAS for Near Real Time products.
Click here to download the Averaging Kernel Matrices of MIPAS for Off-line products.
Click here to download a document describing the Averaging Kernel Matrices of MIPAS for Off-line products.
Click here to download the Averaging Kernel Matrices of MIPAS for the non-target species: CFC-11, ClONO2, N2O5, CFC-12.
Click here to download the profiles corresponding to the atmosphere status for which the Averaging Kernel Matrices have been calculated.
The file IG_GEO.DAT contains the altitude grid where the profiles are represented.
Four directories are provided, one for each season. In each directory the files IG_*.DAT contain the profiles for each species (specified by the file name) and each latitude band (specified within the file).
Please refer to the documents above for explanation on their use.
Systematic Errors
The main error sources that affect the accuracy of the retrieved profiles are:
noise error, due to the mapping of radiometric noise in the retrieved profiles;
temperature error, which maps into VMR retrieved profiles;
systematic error, due to incorrect input parameters.
The noise error and the temperature error are obtainable by the level 2 products distributed by ESA. The systematic errors have been estimated by Oxford University and are downloadable here for the near real time products and here for the off-line products.
For a description of the error analysis performed by Oxford University we refer to the website: http://www.atm.ox.ac.uk/group/mipas/err/.
noise error, due to the mapping of radiometric noise in the retrieved profiles;
temperature error, which maps into VMR retrieved profiles;
systematic error, due to incorrect input parameters.
The noise error and the temperature error are obtainable by the level 2 products distributed by ESA. The systematic errors have been estimated by Oxford University and are downloadable here for the near real time products and here for the off-line products.
For a description of the error analysis performed by Oxford University we refer to the website: http://www.atm.ox.ac.uk/group/mipas/err/.
pT error propagation matrices
In order to make an accurate estimation of the pT error propagation in VMR retrievals it is necessary to propagate the variance-covariance matrix of pT retrieval according to the following formula:
VxpT=E VpT ET
where E is the pT error propagation matrix downloadable here for all the species.
