Issued by: Technical University of Denmark / Sebastian B. Simonsen
Date: 03/05/2021
Ref: C3S_312b_Lot4.D1.IS.3-v3.0_GMB_System_Quality_Assurance_Document_i1.0
Official reference number service contract: 2018/C3S_312b_Lot4_EODC/SC2
History of modifications
List of datasets covered by this document
Related documents
Acronyms
Scope of the document
This document is the System Quality Assurance Document for Gravimetric Mass Balance (GMB) as part of the Copernicus Ice Sheets and Ice Shelves service. It describes the organisation of the data processing system and how product updates are implemented.
Executive summary
The service addresses three essential climate variables (ECVs) by providing four separate products.
- Ice velocity is given for Greenland in product D3.IS.4
- Gravimetric mass balance is given for Greenland and Antarctica in product D3.IS.5
- Surface elevation change is given for:
- Antarctica in product D3.IS.6.1
- Greenland in product D3.IS.6.2
We document here the production and support systems for the CDR v3 for gravimetric mass balance.
The gravimetric mass balance is a brokered dataset, and the system quality and assurance has been previously documented in Forsberg, 2015.
1. System overview
1.1. System elements and interfaces
The gravimetric mass balance is brokered from the Antarctica and Greenland CCI projects. The processing system consists of one ingestion chain which downloads the two datasets from:
- Antarctica: https://data1.geo.tu-dresden.de/ais_gmb/
- Greenland: http://products.esa-icesheets-cci.org/products/downloadlist/GMB/
After the download of the two individual datasets, the data are combined into a common NetCDF-file, which is then available for the end-users of the C3S products.
The CCI-project websites are https://climate.esa.int/en/projects/ice-sheets-antarctic/ and https://climate.esa.int/en/projects/ice-sheets-greenland/ which both have public documentation sections that include their product user guides, algorithm theoretical basis documents and other useful information.
1.2. Hardware, supercomputers and cloud computing
Not applicable for the brokered GMB data, as the creation of the final NetCDF-product is done in a python-environment on a laptop.
2. Upgrade cycle implementation procedure
Not applicable for the brokered GMB data. This is a complete, finished product from the Gravity Recovery and Climate Experiment (GRACE) mission and its follow-on mission GRACE-FO. Currently the processing of the GRACE-FO mission is still in the R&D stage, and data are only provided for the Greenland ice sheet. When available the Antarctic will be added.
3. Procedures for reprocessing CDR's
The GMB have been processed for the initial data release, at the beginning of the data brokering in 2019. With the release of the Greenland GRACE-FO data in 2020, this initial data release has been updated and now the time series are to present. New data releases are monitored and will be incorporated annually. We follow the R&D intensively and as soon we see promising result the brokering of GRACE-FO GMB for Antarctica will be implemented, but at time of writing no schedule for data release is available.
4. System maintenance and system failures
Not applicable for this brokered dataset.
5. User support
The GMB processing team at DTU Space has an account with the Copernicus User Support Jira Service Desk System, to handle level 2 user enquiries through the Jira helpdesk. The user support is provided by:
Contact Person Name: Sebastian Simonsen
E-mail Address: c3s-support@space.dtu.dk
References
Forsberg, R. et al, 2015, System Specification Document (SSD) for the Greenland Ice Sheet CCI Project of ESA's Climate Change Initiative, version v2.1. Available at http://esa-icesheets-greenland-cci.org/index.php?q=webfm_send/111
This document has been produced in the context of the Copernicus Climate Change Service (C3S).
The activities leading to these results have been contracted by the European Centre for Medium-Range Weather Forecasts, operator of C3S on behalf of the European Union (Delegation agreement signed on 11/11/2014). All information in this document is provided "as is" and no guarantee or warranty is given that the information is fit for any particular purpose.
The users thereof use the information at their sole risk and liability. For the avoidance of all doubt , the European Commission and the European Centre for Medium - Range Weather Forecasts have no liability in respect of this document, which is merely representing the author's view.
