The ERA-CLIM Observation Feedback Archive

C. Codorean, D. Dee, H. Hersbach, P. Poli, D. Tan

ECMWF

What is observation feedback?

Why is it useful?

The OFA data server

EMS2013 – The ERA-CLIM Observation Feedback Archive

Observation feedback: Metadata for observations used in reanalysis

What is observation feedback?

For each observation:• Residual relative to model prediction• Quality control indicators• Estimated bias adjustment• Relative weight in the reanalysis• Residual relative to reanalysis estimate

These quantities are derived by using the maximum available information (contextual observations + laws of physics)

EMS2013 – The ERA-CLIM Observation Feedback Archive

Why is observation feedback useful?

1. Information content and traceability of reanalysis products

ERA-20C: 3 Feb 1899

EMS2013 – The ERA-CLIM Observation Feedback Archive

Why is observation feedback useful?

2. Documenting observation usage and quality control

EMS2013 – The ERA-CLIM Observation Feedback Archive

Why is observation feedback useful?

3. Statistical assessment of reanalysis quality

EMS2013 – The ERA-CLIM Observation Feedback Archive

Why is observation feedback useful?

4. Detecting erroneous observations

Mean sea-level pressure observations (ERA-20C, Sep-Nov 1992)

Observed value [hPa]

Mod

el p

redi

ction

[hPa

]

Faulty pressure sensor(not detected until after

ERA-20C production)

EMS2013 – The ERA-CLIM Observation Feedback Archive

Why is observation feedback useful?

5. Improving bias adjustments for observations

EMS2013 – The ERA-CLIM Observation Feedback Archive

Why is observation feedback useful?

5. Improving bias adjustments for observations

Analysis residuals:

Bias adjustments for satellite radiances:

EMS2013 – The ERA-CLIM Observation Feedback Archive

Access to reanalysis products

Data policy:• All gridded reanalysis products available, for research & commercial• All input observations available, for research only

ERA Data Servers:• All gridded reanalysis data and derived fields• Relies on ECMWF’s Meteorological Archiving and Retrieval System (MARS)• Currently >12,000 registered users of ERA-Interim data• Interactive access via web; batch access using scripts (preferred)

Observation Feedback Archive:• All input observations used in reanalysis – traceable to source • Web interface with dynamic data selection, and script access• Facilities for data visualization and downloading• Relies on a simple generic observation database (ODB) + tools

EMS2013 – The ERA-CLIM Observation Feedback Archive

New data server at http://apps.ecmwf.int/datasets/

Coming soon:• ERA-20C + feedback • ERA-Interim feedback