Differences

This shows you the differences between two versions of the page.

--- clipc:start [2015-06-30 09:28:42]
andreasd
+++ clipc:start [2016-11-03 13:19:38]
andreasd [Description of the Met Norway method]
@@ Line 1: / Line 1: @@
-====== CLIPC - Bias-corrected data ======
+====== CLIPC Bias-Correction======
+===== Available bias-corrected data =====
-[[http://www.clipc.eu|The CLIPC project]] provides access to climate information of direct relevance to a wide variety of users, from scientists to policy makers and private sector decision makers. Information will include data from satellite and in-situ observations, climate models and re-analyses, transformed data products to enable impacts assessments and climate change impact indicators.
+Bias-corrected EUR-44 CORDEX and EUR-11 CORDEX RCM data made by SMHI, IPSL and Met Norway for CLIPC are now **available** (with others) through the [[https://esgf-data.dkrz.de/search/esgf-dkrz/|ESGF]] project "CORDEX-Adjust".
+More information can be found [[http://www.cordex.org/index.php?option=com_content&view=article&id=275&Itemid=785|here]].
-This page documents the datasets produced by the Meteorologisk institutt within [[http://www.clipc.eu|the CLIPC project]] under the deliverable ”D6.1 : Climate model data for Europe, bias-corrected when necessary, for CCII-T1 calculation. Documented dataset”. The deliverable is focussing on bias-corrected data at three different resolutions:
+PLEASE REPORT to [[andreas.dobler@met.no|Andreas Dobler]], if you find something strange or errors in the Met Norway data.
-  - Global climate model (GCM) data interpolated to a common 2° × 2° grid,
-  - Regional climate model (RCM) data at the EURO-CORDEX 0.44° (~ 50 km × 50 km) grid
-  - RCM data at the EURO-CORDEX 0.11° (~ 12 km × 12 km) grid
-The Meteorologisk institutt will provide data for 2. and 3.
+Please have a look at some [[evaluation]] plots considering the bias-corrected data from Met Norway.
-Currently, the bias-corrected datasets are available through links on this page (see below) and at the [[http://www.clipc.eu/the-project/public-deliverables-and-milestones/milestones#m25|CLIPC milestone page]] but will eventually become available through [[http://esgf.llnl.gov/|ESGF]]. The datasets now published as CLIPC Deliverable D6.1 is one of the first ensemble of multi-method bias correction datasets derived from the published EURO-CORDEX RCM ensemble at two spatial resolutions and complemented by bias corrected GCM data.
+An overview on the bias-corrected data from Met Norway can be found here {{:clipc:BiasCorrectedDataList.pdf|}}
-===== News =====
+===== Project and deliverable summary =====
-  * Bias corrected EUR44-CORDEX and EUR11-CORDEX RCM data from SMHI are available [[http://exporter.nsc.liu.se/b780c1ede6904458829bae06bb99779d|here]]
+[[http://www.clipc.eu|The CLIPC project]] provides access to climate information of direct relevance to a wide variety of users, from scientists to policy makers and private sector decision makers. Information will include data from satellite and in-situ observations, climate models and re-analyses, transformed data products to enable impacts assessments and climate change impact indicators.
-  * Bias corrected EUR11-CORDEX RCM data from Met Norway are available at [[http://arcticdata.met.no/metamod/search/page/1/result?active_criteria=&freetext_13=clipc|the Arctic Data Centre]] ([[http://thredds.met.no/thredds/catalog/arcticdata/met.no/CLIPC/catalog.html| Thredds catalog]])
+**This page** documents the datasets produced by the Meteorologisk institutt within [[http://www.clipc.eu|the CLIPC project]] under the deliverable ”D6.1 : Climate model data for Europe, bias-corrected when necessary, for CCII-T1 calculation. Documented dataset”. The datasets is one of the first ensemble of multi-method bias-corrected datasets derived from the [[http://www.euro-cordex.net/|EURO-CORDEX]] RCM ensemble at two spatial resolutions and complemented by bias-corrected GCM data:
+  - Bias-corrected regional climate model (RCM) data at the EURO-CORDEX 0.11° (~ 12 km × 12 km) grid
+  - Bias-corrected RCM data at the EURO-CORDEX 0.44° (~ 50 km × 50 km) grid
+  - Bias-corrected global climate model (GCM) data interpolated to a common 2° × 2° grid,
+The Meteorologisk institutt provides bias-corrected data at the EURO-CORDEX 0.11° and the EURO-CORDEX 0.44° grid. These will also contribute to the Bias Correction Intercomparison Project [[http://www.meteo.unican.es/en/node/73279|BCIP]].
-NOTE THAT THIS IS ARE PRELIMINARY DATA PUBLICATIONS. DATA FORMAT, AVAILABILITY AND CONTENT MAY CHANGE WITHOUT NOTICE.\\
-PLEASE: REPORT, IF YOU FIND SOMETHING STRANGE IN THE DATA to [[andreas.dobler@met.no|Andreas Dobler]]
 ===== Terms of use=====
-All EURO-CORDEX simulations are published under the [[http://cordex.dmi.dk/joomla/images/CORDEX/cordex_terms_of_use.pdf|CORDEX terms of use]]. Until further notice, the terms of use for the bias-corrected data are the same as those from the uncorrected EURO-CORDEX simulations obtained from ESGF servers (and an overview on the restriction will follow as soon as the ESGF servers are online again).
+All EURO-CORDEX simulations are published under the [[http://cordex.dmi.dk/joomla/images/CORDEX/cordex_terms_of_use.pdf|CORDEX terms of use]]. Until further notice, the terms of use for the bias-corrected data from CLIPC are the same as those from the uncorrected EURO-CORDEX simulations obtained from ESGF servers. These are:
+  * All simulations have non-restricted use
-We acknowledge the following grants and work. Please include them when using or redistributing the bias-corrected CLIPC data.
+We acknowledge the following grants and work. Please acknowledge/cite these when you use or redistribute the bias-corrected CLIPC data from Met Norway.
   * The CLIPC EU project (grant agreement #607418)
-  * The EURO4M FP7 project (grant agreement #242093) for the EURO-CORDEX 0.11° reference/training data [[http://www.euro4m.eu/downloads/D2.4_Improved_MESAN_downscaled_dataset_at_3-12_km_resolution_for_most_of_the_past_20_yr_period.pdf"
+  * The EURO4M FP7 project (grant agreement #242093) and Hāggmark, L., Ivarsson, K.-I., Gollvik, S. and Olofsson, P.-O., 2000: MESAN, an operational mesoscale analysis system. Tellus A, 52: 2–20. doi: 10.1034/j.1600-0870.2000.520102.x for the EURO-CORDEX 0.11° reference/training data [[http://www.euro4m.eu/downloads/D2.4_Improved_MESAN_downscaled_dataset_at_3-12_km_resolution_for_most_of_the_past_20_yr_period.pdf |MESAN]]
-|MESAN]]
+  * Gudmundsson, L., Bremnes, J. B., Haugen, J. E., and Engen-Skaugen, T., 2012: Technical Note: Downscaling RCM precipitation to the station scale using statistical transformations -- a comparison of methods. Hydrol. Earth Syst. Sci., 16, 3383-3390, doi:10.5194/hess-16-3383-2012 for the bias-correction method used by Met Norway (quantile mapping).
-  * Gudmundsson, L., Bremnes, J. B., Haugen, J. E., and Engen-Skaugen, T., 2012: Technical Note: Downscaling RCM precipitation to the station scale using statistical transformations – a comparison of methods, Hydrol. Earth Syst. Sci., 16, 3383-3390, doi:10.5194/hess-16-3383-2012 for the bias-correction method (quantile mapping).
-===== Description of Met Norway method =====
+===== Description of the Met Norway method =====
-The method from the Meteorologisk institutt uses the R package [[http://cran.r-project.org/web/packages/qmap/index.html|qmap: Statistical transformations for post-processing climate model output]]. Basically, it performs a quantile mapping of the simulated time series to observed ones for each grid point. It does so by estimating values for regularly spaced quantiles of the empirical cumulative distribution function and using these estimates to perform a quantile mapping. Details on the method can be found in Gudmundsson et al. (2012, doi:10.5194/hess-16-3383-2012). The set-up includes a linear interpolation between the fitted transformed values, and simulated values lying outside the range of the training period (e.g., from climate projections) are extrapolated using the correction found for the highest quantile of the training period, as suggested by Boé et al. (2007, doi: 10.1002/joc.1602). Furthermore, the method includes an adjustment of wet-day frequencies.
+The method from the Meteorologisk institutt uses the R package [[http://cran.r-project.org/web/packages/qmap/index.html|qmap: Statistical transformations for post-processing climate model output]]. Basically, it performs a quantile mapping of the simulated time series to observed ones for each grid point. It does so by estimating values for regularly spaced quantiles of the empirical cumulative distribution function and using these estimates to perform a quantile mapping. Details on the method can be found in Gudmundsson et al. (2012, doi:10.5194/hess-16-3383-2012). The set-up includes a linear interpolation between the fitted transformed values, and simulated values lying outside the range of the training period (e.g., from climate projections) are extrapolated using the correction found for the highest quantile of the training period, as suggested by Boé et al. (2007, doi: 10.1002/joc.1602). Furthermore, the method includes an adjustment of wet-day frequencies for precipitation. For temperature, the quantile mapping takes into account the main trend by subtracting the (5-year) mean before the quantile mapping and adding it again afterwards. This is expected to reduce the impact on the mean climate change signal.
+\\
-So far, the GCM-RCM model combinations listed in Table 1 have become available at 0.11° from EURO-CORDEX and have been corrected. The bias correction has been applied to the variables precipitation (pr) and near-surface air temperature (tas). Further corrections will include daily minimum near-surface air temperature (tasmin) and daily maximum near-surface air temperature (tasmax). =====
+  * For the bias-corrected EUR-11 CORDEX data, the [[http://exporter.nsc.liu.se/620eed0cb2c74c859f7d6db81742e114/|daily 0.11° MESAN data]] has been used as reference/training data covering 1989-2010. The complete historical RCM data has been used for calibration.
+  * For the bias-corrected EUR-44 CORDEX data, the [[http://www.ecad.eu/download/ensembles/ensembles.php|daily 0.44° EOBS12 data]] has been used as reference/training data covering 1981-2010. For calibration the RCM data has been restricted to the same period (1981-2010) following the [[http://www.meteo.unican.es/en/node/73279|BCIP]] experiment design.
+(Scripts etc.: [[procedure]])
+===== Known issues =====
+Please note the following:
+  * There is a small remaining overall bias due to the use of “only” 101 quantiles to estimate the empirical cumulative distribution functions within qmap. See pdfs on [[evaluation]].
+  * There are additional remaining seasonal biases due to the calibration process which is carried out without splitting into seasons or months. See pdfs on [[evaluation]].
+  * The bias-correction method does not guarantee the conservation of climate change signals. The impact on the projected changes in mean conditions is relatively small, as can be seen here:\\
+{{:clipc:ClimChangeSignal_tas.pdf|}}\\
+{{:clipc:ClimChangeSignal_pr.pdf|}}\\
+{{:clipc:ClimChangeSignal_pr_rel.pdf|}}\\
+  * There are some days in the MESAN data when tasmax < tas or tas < tasmin. In the current set-up this is handed down to the bias-corrected data.
+While the first three points are a result of the idea to keep the method **very** simple (at least for the beginning), the last point is under investigation and may be fixed in a later version.
-\\
-\\
-\\
 ----
-[[andreas.dobler@met.no|Andreas Dobler]] 2015/06/30 09:02//
+ //[[andreas.dobler@met.no|Andreas Dobler]] 2015/07/15 11:00//