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Reference ID

Document

D1

Climate Algorithm Theoretical Basis Document (C-ATBD) for Daily OLR CDR v01r02

https://www.ncei.noaa.gov/pub/data/sds/cdr/CDRs/Outgoing%20Longwave%20Radiation%20-%20Daily/AlgorithmDescription_01B-21.pdf 

D2

Copernicus User Support Handbook, V2.1

ftp link to the handbook1

last accessed on 31/05/2022

D3

Clerbaux, N., Velazquez Blazquez, A., Baudrez, E., Aebi, C., Akkermans, T., 2022, C3S Product Quality Assurance Document - Earth Radiation Budget data from NOAA / NCEI HIRS OLR v01r02 (daily and monthly)

C3S2_D312a_Lot1.1.2.1-v1.0_202103_PQAD_HIRS_OLR_v01r02

Available via : https://cds.climate.copernicus.eu/cdsapp#!/dataset/satellite-earth-radiation-budget?tab=doc

D4

Lee, H.-T., 2018, Quality Assurance Results and Summary for Monthly and Daily OLR CDR (rev.20180831).

http://olr.umd.edu/References/QA_Summary_OLR-Monthly_and_Daily_CDR_20180831.pdf


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1 Use FileZilla, WinSCP, Wget or other application to access this FTP site


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In addition to these annual files, an interim version (with “preliminary” in the name) that corresponds to the Interim Climate data record (ICDR) concept are also made available, e.g.

https://www.ncei.noaa.gov/thredds/dodsC/cdr/olr-daily/olr-daily_v01r02-preliminary_20220101_20220521.nc.html

1.3 Hardware and data server system – RMIB "go-between" server

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These separated daily HIRS OLR files can be accessed on the RMIB “go-between” server. The daily data files can be access via the generic URL which is of the form:

“https://gerb.oma.be/c3s/data/hirs-olr-daily/tcdr/v1.2/olr/YYYY/MM/DD”

where YYYY, MM, and DD are the calendar year, month and day. For instance:

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with “preliminary” added to the file name:

“https://gerb.oma.be/c3s/data/hirs-olr-daily/icdr/v1.2/olr/YYYY/MM/DD”

 e.g., https://gerb.oma.be/c3s/data/hirs-olr-daily/icdr/v1.2/olr/2023/01/20

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Specifically, the command to download a single day takes the form shown in the box below (where YYYY,MM,DD are the year, month and day). This command is executed for all the day/month/year which are present in the yearly files on the NOAA server.

A script is run automatically each night (at 05:00 UTC) and any new files or changes to existing yearly files on the NOAA server are detected. In case of a new/updated file, the daily data corresponding to the relevant year are extracted using the command in the box below. In practice, this daily extraction concerns the preliminary files from which new data are available (approximately) each day and are added to the icdr part of the go-between server. Once per year, the preliminary data are replaced by final data, and in this case also the corresponding daily data are extracted and added to the tcdr part of the go-between server.

Command used to extract the daily HIRS OLR files

#!/bin/bash

YYYY=2008
MM=11
DD=07

OUT=data_312a_Lot1_hirs-olr-daily_tcdr_v1.2_olr_YYYY_MM_DD.nc
URL=

https://www.ncei.noaa.gov/thredds/ncss/cdr/olr-daily


FILE=olr-daily_v01r02_${YYYY}0101_${YYYY}1231.nc
VAR="var=olr"
T_START="time_start=${YYYY}${MM}${DD}T00%3A00%3A00Z"
T_END="time_end=${YYYY}${MM}${DD}T23%3A59%3A59Z"

wget –O ${OUT} '${URL}/${FILE}?${VAR},${T_START}?${T_END}'


Following this request and the retrieval of the daily data file onto the RMIB server, the following 3 global attributes within the NetCDF file have to be changed as the output file contains a single day of data and not the full year anymore. This is done using 'cdo' for the following variables which are changed from

:time_coverage_start = "1979-01-01T00:00:00.00Z" ;
:time_coverage_end = "1979-12-31T23:59:59.99Z" ;
:time_coverage_duration = "P365D" ;

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The data products brokered from the NOAA/NCEI are served to the C3S CDS (pull mode) from an OPeNDAP server hosted by NOAA/NCEI: https://www.ncei.noaa.gov/thredds. However, as long as OPeNDAP functionality is not implemented in the CDS, the RMIB's go-between server is used:

"https://gerb.oma.be/c3s/data/hirs-olr-daily/tcdr/v1.2/olr/YYYY/MM/DD"

where YYYY, MM, DD are the requested year, month and day respectively. The planned outages of the server, and therefore the availability of data, will be communicated as far as possible to the CDS well in advance. Any notification procedures requested by the CDS will be complied with.

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