Contributors: R. Gray (Met Office)
Issued by: Met Office/Rory Gray
Date: 06/10/2020
Ref: C3S_D312b_Lot1.2.3.9-v1.0_201910_SQAD-ICDR_ECV_WVP_UTH_v1.0.1
Official reference number service contract: 2018/C3S_312b_Lot1_DWD/SC1
History of modifications
List of datasets covered by this document
Related documents
Acronyms
General definitions
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Scope of the document
This document describes the systems used for delivering the MW UTH products to the Climate Data Store (CDS) of the Copernicus Climate Change Service (C3S). Interfaces to external data, the infrastructure for data processing (if applicable), and the interface to the CDS are outlined. Information about new data cycles and reprocessing are also provided in this document. Internal procedures for managing and communicating system maintenance, and for user support are described.
Executive summary
The MW UTH ICDR dataset is a measure of the upper tropospheric water vapour with global coverage twice a day. The UTH is inferred from the operational microwave humidity sounder, the Microwave Humidity Sounder (MHS), with the ICDR product using measurements covering the time span 1/1/2016 to 31/5/2019. This product can be compared with the corresponding quantity in climate models and to infer trends.
The dataset is made accessible via DWD's webserver at https://c3s.satproj.klima.dwd.de/data/ and can be ordered via HTTP protocol. The data are password-protected. Login details are provided to the CDS team via the entry in the Harmonised Table. Respective outages will be kept to a minimum and, whenever possible, communicated to C3S in advance.
The MW UTH ICDR product continues the time series started from the CM SAF dataset (1999-2015). A simple relationship relates the brightness temperatures to MW UTH. The processing is carried out on Met Office research linux clusters and the output file is then provided to DWD to be included as part of the C3S product portfolio.
We provide user support for queries relating to our products when forwarded to us by C3S.
1. System overview
1.1 System elements and interfaces
The interfaces for acquiring the satellite data and delivering the MW UTH ICDR dataset to C3S are described in this section.
1.1.1 Interfaces to external data
Generated ICDR products
The ICDR product is generated daily from satellite data downloaded via ftp from NOAA's Comprehensive Large Array-data Stewardship System (CLASS) data distribution facility ( www.class.noaa.gov ). The product files are then transferred via ftp to the 'incoming.dwd.de' ftp server at the DWD.
1.1.2 Delivery of the data to C3S
The data are made accessible via DWD's webserver at https://c3s.satproj.klima.dwd.de/data/. All data provided for the CDS by DWD will be uploaded to this server. It can be accessed via HTTP protocol. Exact addresses of the provided files will be provided to the CDS upon submission. This allows automated access to the files, e.g. via scripts handling the delivery chain of an order in the CDS from the server to the user. We aim for a 99% availability of the data server, with 95% of the data transactions happening at a rate of 10 Mbit/s or faster.
1.2 Hardware, supercomputers and cloud computing
1.2.1 Computing infrastructure
A linux based cluster is used at the Met Office to compute the MW UTH product from the ICDRs. This is part of the Met Office research computing infrastructure.
1.2.2 Back-up
Data brokered from other sources are not backed up because in the case of data corruption or loss on the data server, which serves as interface to the CDS, they can be downloaded again from their original, dedicated sources, where back-ups outside our responsibilities are maintained.
1.2.3 Webserver at DWD
DWD hosts the webserver (CentOs Linux) that can be accessed from outside the DWD firewall via HTTP. Monitoring of server availability is routinely performed using Nagios IT Infrastructure Monitoring Tool. The check is performed every 60 second and if the data on the webserver are unavailable, an automatic email notification is issued.
Preliminary analysis of the required disk space for data sets provided by DWD within C3S_312b_Lot1 necessary disk space shows that the quota on the data server dedicated to DWD's efforts within C3S_312b_Lot1 will not be exceeded.
2. Upgrade cycle implementation procedure
Extensions to this dataset will proceed as new data becomes available. After having been produced, the extension will be brokered to the CDS, as hitherto. These will be brokered six monthly.
3. Procedures for reprocessing CDRs
No reprocessing of the WV UTH ICDR dataset is foreseen as part of this project. Reprocessing is possible in the future, dependent upon improvements developed in the CM SAF.
4. System maintenance and system failures
In general, any issues with IT infrastructure that either delays delivery of data or impedes access to data via the CDS will be documented in the Quarterly Report.
4.1 Interfaces to external data
This section discusses treatment of delays at interfaces to external data sources.
4.1.1 Brokered data
It is beyond the scope of our responsibility to safeguard the stability of services and data servers of external providers. If we become aware of issues at their end that will impede the timely delivery of brokered data, we will notify C3S.
4.1.2 Input data sets for generated ICDRs
Unexpected system outages will be treated according to internal regulations and procedures at the Met Office's IT department. The IT department will record and resolve the issue according to their procedures and provide notifications as appropriate.
4.2 Production of data sets
Unexpected outages and failures to produce the data sets will be notified to DWD as appropriate.
4.3 Interface to the CDS
This section discusses maintenance and outages of the data server hosting the files for access through the CDS.
4.3.1 Planned maintenance
Planned outages of the data server on which the CDS accesses the files are kept to a minimum. However, software updates may become necessary, or hardware may need to be maintained or replaced. Such planned outages will be communicated to the CDS as early as possible. Respective notifications will be issued by DWD's IT department and delivered to the DWD-based members of the Service Management Team of C3S_312b_Lot1, who will ensure prompt passing on to the CDS. We do not expect to contact users of data sets submitted by us directly, communication will be to the CDS only.
We are open to requests by C3S to schedule dates on which no planned maintenance involving an outage should be carried out. Although a respective commitment by the IT department cannot be guaranteed, we always strive to respect such requests.
4.3.2 Unplanned outages
Unexpected system outages will be treated according to internal regulations and procedures at DWD's IT department. This involves notification of the DWD-based members of the Service Management Team, who will in turn notify C3S of the outage as quickly as possible. The IT department will resolve the issue according to their procedures and notify C3S, again via the Service Management Team.
5. User support
5.1 Enquiries
The user (customer) has the possibility to browse and search in the Copernicus Knowledge Base (CKB) (CAMS and C3S Knowledge Base (CKB)) or the Copernicus Climate Data Store desk (https://cds.climate.copernicus.eu/contact-us). This is known as the level-0 process of User Support.
Figure 1: The schematic of Copernicus User Support (Copernicus User Support Handbook, V2.1)
Contact and User Support process on JIRA service desk
If the level-0 support fails to answer the user's query, they may then make a request, which is sent to the Copernicus User Support (CUS) Service team at ECMWF. These (level-1) requests will be handled within 8 hours.
For any scientific and specialist enquiries that cannot be answered by the CUS team at ECMWF or addressed by the Copernicus Knowledge Base, the request will be forwarded to the Copernicus User Support Specialists (level-2).
Enquiries forwarded to the Copernicus User Support Specialist team will be acknowledged within 3 working days (target 100%) and a notification sent to the user. This step is handled on the JIRA 1 Service Desk established at ECMWF for the current project. In case of specific scientific issues, the enquiries will be channeled to the ECV and data specialist of the C3S2_312a_Lot1 project and should be resolved within 3 working weeks (target 85%). In case of brokered datasets, the data specialist may choose to contact the responsible team at the provider level if they cannot resolve the issue on their own. In each yearly quarter, we aim for User Support satisfaction scoring 3 in 90% of all voluntary based feedbacks by users, with 1 (very unsatisfied) to 5 (very satisfied). We will also list the number of tickets raised by users on the JIRA system in the Quarterly Report.
- JIRA: Project management software tool created by Atlassian company ↩
