1 / 4

Monthly averages: discussion item

Monthly averages: discussion item. J E Russell Imperial College, London j.e.russell@imperial.ac.uk. Monthly averages: original proposal. Monthly mean products would include: time-step mean: 15 minute monthly average diurnal product for clear and all-sky

donter
Télécharger la présentation

Monthly averages: discussion item

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Monthly averages: discussion item J E Russell Imperial College, London j.e.russell@imperial.ac.uk

  2. Monthly averages: original proposal • Monthly mean products would include: • time-step mean: 15 minute monthly average diurnal product for clear and all-sky • Overall monthly mean for clear and all-sky (sum of 15 minute averages) • Produced at RAL from the BARG Edition product (already an average over an exact 15 minute period) • Requires night-time cloud flag • Would benefit from additional clear sky information added to the BARG determined from the HR data – these could be adjusted by clear sky specific correction factors. • All sky = summation of all data where none missing • Clear sky missing points filled by interpolation based on diurnal models (albedo interpolated in SW according to ADM) • Anticipated that missing all sky data would be treated in the same way where appropriate and consistent with GERB processing

  3. Monthly averages: CM-SAF products • Monthly mean products would include: • time-step mean: hourly average diurnal product for all-sky • Overall monthly mean for all-sky (sum of hourly averages) • Produced at RMIB from the GERB ARCH (high resolution snapshot data) • ARCH fluxes (at SEVIRI acquisition times) interpolated in time and integrated by trapezium rule • Missing all-sky points filled with GERB-like (where present) corrected with gross factor to adjust between GERB and GERB-like fluxes. This includes SZA > 80 and sunglint, both of which have GERB radiance observations. • Currently no separate clear sky average • Requires night-time cloud flag • Would benefit from additional clear sky information added to the BARG determined from the HR data – these could be adjusted by clear sky specific correction factors.

  4. Monthly averages • CM-SAF advantages and disadvantages • CM-SAF represents a cheap solution in that already produced by RMIB, thus the availability of the average product should be more rapid • Will free up man-power at RAL to allow addressing of more fundamental issues of product improvement • In common with the RAL based solution still requires additional clear sky for which night-time cloud flags are needed. Unlike the RAL solution the production of the clear sky average may have to re-specified for consistency with the all sky product • Not the ideal or most obvious GERB monthly average product and will be harder to validate, so may in fact not be available validated any sooner than the RAL solution. • Not consistent with the GERB BARG data, uses more GERB-like data to fill than required, based on ARCH data which is not a standard GERB product, not planned to be part of the edition archive and the furthest from validation • Co-ordination of reprocessing or updates with the GERB products may be problematic as produced as part of an external project

More Related