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GCW Data Protocol




The World Meteorological Organization's Global Cryosphere Watch (GCW – see globalcryospherewatch.org) is an international mechanism for supporting observations of all components of the Earth´s cryosphere, including snow cover, glaciers, ice caps, ice sheets, sea ice, lake and river ice, permafrost, seasonally frozen ground, and solid precipitation. GCW aims to provide authoritative, clear, and useable data, information, and analyses on the past, current and future state of the cryosphere. Improving access to data and products is a fundamental objective of GCW.


The core of the GCW surface observing network is called CryoNet. This network is comprised of stations and sites which meet certain requirements. The GCW surface network is a component of the WMO Integrated Global Observing System (WIGOS). Through WIGOS and the WMO Information System (WIS), GCW provides a fundamental contribution to the Global Earth Observations System of Systems (GEOSS).


The principles enshrined in this GCW Data Protocol must be applied to qualified data from each station and site operated under the auspices of GCW, including submission of metadata and data per an agreed timetable. The GCW CryoNet Team is responsible for the Data Protocol. Questions about the policy and its implementation should be directed to the CryoNet Team lead.




The purpose of the GCW Data Protocol is to support the objectives of the Global Cryosphere Watch, which include the development of CryoNet, data and information delivery on the state of the cryosphere, and the creation of a data portal. The objective of GCW data management is to ensure the security, integrity, accessibility and free exchange of relevant data that support current research and future use of the data. The GCW Data Protocol provides initial guidance for meeting this objective. More detailed guidance is provided in separate GCW documents.


Data definition


As used here, “GCW data” includes data from stations and sites operated by the core GCW surface observing network, CryoNet, and data from contributing stations that are not part of CryoNet. All CryoNet data are produced in accordance with the minimum requirements set out for CryoNet stations and sites (see )http://globalcryospherewatch.org/cryonet/requirements.html), and with the procedures laid out in the GCW Best Practices Manual and GCW Best Practices Guide. Contributing stations may not necessarily meet the CryoNet station requirements and may not be compliant with GCW best practices. This data protocol applies to both CryoNet and contributing station data that are available through the GCW Data Portal. All stations are expected to meet GCW requirements by the beginning of the operational phase on 1 January 2020.




Metadata are essential to the discovery, access, and effective use of data. Metadata may be defined as all the information necessary for data to be independently understood by users and for ensuring proper stewardship of the data. All GCW observational data and products must be accompanied by metadata that document and describe the data. The metadata must be in a “machine readable” (i.e. digital) form. Regardless of any data access restrictions or delays in delivery of the data itself, operators of GCW CryoNet stations and sites should promptly provide basic descriptive metadata for datasets (WIS metadata) and observations facilities (WIGOS metadata) in an internationally recognized, standard format to the GCW Data Portal. When submitting data to the Data Portal, contributors should adhere to GCW’s best practices for data, as detailed in the following documents:


Guidelines for Data Centres Contributing to GCW

Operational Manual for Data Centres Contributing to GCW


Data availability and exchange


The Global Cryosphere Watch aims to make observational data and ancillary data freely available through its Data Portal, and whenever possible in near real-time. The data management is based on the FAIR Data Principles (Wilkinson et al. (2016). The GCW Data Portal is a web interface that contains information about datasets (metadata), but not the data themselves. Instead, it links to datasets that are stored at partner data centres. It is compatible with the WMO Information Service (WIS). Linkages between the GCW Portal and data partners/providers are illustrated at http://globalcryospherewatch.org/data/data.html.


At its Seventeenth Congress in 2015 (Cg-17), WMO agreed on Resolution 60 concerning the WMO policy for the international exchange of data and products to support the Global Framework for Climate Services (GFCS). Resolution 60 noted a number of other resolutions, including Resolution 40 (Cg-XII) on the policy and practice for the exchange of meteorological and related data and products including guidelines on relationships in commercial meteorological activities, and Resolution 25 (Cg-XIII) for the exchange of hydrological data. Resolution 40 adopts the following policy:


As a fundamental principle of the World Meteorological Organization (WMO), and in consonance with the expanding requirements for its scientific and technical expertise, WMO commits itself to broadening and enhancing the free and unrestricted international exchange of meteorological and related data and products.


The GCW Data Protocol will adhere to the above-mentioned resolutions and to the following open-access resolutions passed by international scientific organizations in the past 20 years:


·      ICSU 1996 General Assembly Resolution

·      ICSU Assessment on Scientific Data and Information

·      Article III-1c from the Antarctic Treaty

·      Intergovernmental Oceanographic Commission Data Exchange Policy


Full and open access” is defined by ICSU (2004) as equitable, non-discriminatory access to all data preferably free of cost, but some reasonable cost-recovery is acceptable. WMO Resolution 40 uses the terms "free and unrestricted" and defines these terms as meaning "non-discriminatory and without charge". "Without charge" in the context of this resolution means at no more than the cost of reproduction and delivery without charge for the data and products themselves.


Data preservation


Recognizing that the true value of scientific data is often realized long after they have been collected, it is essential to ensure long-term preservation and sustained access to GCW data. All GCW data must be archived in their simplest, useful form and be accompanied by a complete metadata description (including export of discovery metadata to the GCW Portal). Given that the GCW Data Portal does not store data, long-term preservation of GCW datasets is generally the responsibility of the data providers.


Data acknowledgment/attribution


To recognize the valuable role of data providers (those who collect, prepare, and provide the data) and to facilitate repeatability of experiments in keeping with the scientific method, users of GCW data must formally acknowledge data authors (contributors) and sources. Where possible, this acknowledgment should take the form of a formal citation, such as when citing a book or journal article. GCW encourages data citation according to the principles outlined by DataCite (https://www.datacite.org/), and recommends the form:


Creator (Publication year)







Doe. J. (2016).

Arctic Sea Ice Extent 1900-2016. Version 1.

My Institute/My Data Centre.



[Accessed 2016-11-25]


To simplify this process, GCW recommends that all datasets have a digital object identifier (DOI).




Data protocol documents created by SCAR, IPY, SVALI, IASC and the ICSU WDS data sharing principles were consulted during preparation of this document (see References).




The Antarctic Treaty. 1959. Available at: http://www.ats.aq/.

International Polar Year 2007–2008 Data Policy (version 1.2). Available at: http://classic.ipy.org/Subcommittees/final_ipy_data_policy.pdf.

ICSU (International Council for Science). 2004. ICSU Report of the CSPR Assessment Panel on Scientific Data and Information. Available at: http://www.icsu.org/publications/reports-and-reviews/priority-area-assessment-on-scientific-data-and-information-2004/paa-data-information.

Intergovernmental Oceanographic Commission Oceanographic Data Exchange Policy. 2003. Available at http://www.iode.org/contents.php?id=200.

Resolution of the International Council of Science (ICSU) General Assembly (24–27 September 1996). See: http://oldwww.iucr.org/iucr-top/cexec/rep96/icsu.htm.

SCAR Data Policy (2011). Scientific Committee for Antarctic Research. SCAR Report 39. Available at:


SVALI data policy (2011). Declaration of Intent between the Nordic Centres of Excellence (NCoE) within the sub-programme Interaction between Climate Change and the Cryosphere (ICCC) regarding an Open Data Policy. Nordic Top-level Research Initiative (2011). Available at: https://www.wmo.int/pages/prog/www/OSY/Meetings/GCW-CN1/INF21_Svali_Data_Policy.pdf.

Wilkinson, M. D., et al. (2016). The FAIR Guiding Principles for scientific data management and stewardship. SCIENTIFIC DATA 3:160018, DOI: 10.1038/sdata.2016.18.

World Data System Data Sharing Principles (2015). WDS Scientific Committee.

DOI: 10.5281/zenodo.34354                    Available at:


World Meteorological Organization Congress, Resolution 60 (Cg-17, 2015): WMO Policy for the International Exchange of Climate Data and Products to Support the Implementation of the Global Framework for Climate Services.

World Meteorological Organization Congress, Resolution 40 (Cg-XII, 1995): WMO Policy and Practice for the Exchange of Meteorological and Related Data and Products Including Guidelines on Relationships in Commercial Meteorological Activities. Available at http://www.wmo.int/pages/prog/www/ois/Operational_Information/Publications/Congress/Cg_XII/res40_en.html.

World Meteorological Organization Congress, Resolution 25 (Cg XIII, 1999). Exchange of Hydrological Data and Products. Available at: http://www.wmo.int/pages/prog/hwrp/documents/Resolution_25.pdf.




To create a framework for sustained in-situ and satellite-based observations of snow, ice and permafrost, GCW has formed partnerships with several international organizations that coordinate monitoring of individual components of Earth´s cryosphere, and with major data centres and distribution networks. Data partners include (in alphabetical order):


AARI            Arctic and Antarctic Research Institute, St. Petersburg, Russia

BAS             British Antarctic Survey, Cambridge, UK

ESA             European Space Agency

CCIN            Canadian Cryosphere Information Network

CryoClim       Norwegian Space Centre (NSC), Oslo, Norway

IASC            International Arctic Science Committee

ICSU            International Council for Science

IPY              International Polar Year

NSIDC          National Snow and Ice Data Center, Boulder, Colorado, USA

SCAR           Scientific Committee on Antarctic Research

SVALI          Stability and Variations of Arctic Land Ice

WDS            World Data System


(A PDF version of the Data Protocol is available here.)

Revised: 27 November 2017