International initiatives for the climate monitoring

Space agencies coordinate their response to these needs via the Coordination Group of Meteorological Satellites (CGMS) and the Committee for Earth Observation Satellites (CEOS) that jointly established the CEOS/CGMS Working Group on Climate (WGClimate). This joint working group implements the Architecture for Monitoring Climate from Space and has been assigned three overarching objectives:

• Providing a comprehensive and accessible view of existing and planned climate data records
• Delivering further climate data records, including multi-mission, through best use of available data.
• Optimise the planning of future satellite missions and constellations to expand existing and planned climate data records.

The first goal is about creating a list of climate data records that focus on Essential Climate Variables (ECVs) as defined by the Global Climate Observing System (GCOS). This list is called the ECV inventory.

Specific gap analyses based on the ECV Inventory and a coordinated action plan address the second and third objectives of the joint working group.

Fundamental Climate Data Records (FCDRs) and Essential Climate Variables (ECVs)

• Fundamental Climate Data Records (FCDRs) (or a level-1 data): A Fundamental Climate Data Record (FCDR) is a well-characterised, long-term data record, usually involving a series of instruments, with potentially changing measurement approaches, but with overlaps and calibrations sufficient to allow the generation of products that are accurate and stable, in both space and time, to support climate applications. FCDRs are typically calibrated radiances, backscatter of active instruments, or radio occultation bending angles. FCDRs also include the ancillary data used to calibrate them. The term FCDR has been adopted by GCOS and can be considered as an international consensus definition. (Example).
• Thematic Climate Data Records (TCDRs) (or level-2-3 data): A Thematic Climate Data Record (TCDR) is the counterpart of the FCDR in geophysical space. TCDRs that consists of a consistently processed time series of uncertainty-quantified retrieved values of a geophysical variable or related indicator, located in time and space, and of sufficient length and quality to be useful for climate science or applications (Example)
• Interim Climate Data Records (ICDRs): ICDRs that are consistently processed times series of uncertainty-quantified estimates of CDR values produced with better timeliness than, but otherwise minimizing differences with, the estimated CDR values. ICDRs are important to monitor climate closer to real time and actual developments of sea ice concentrations are a good example for that.

Lets study important terminologies one by one. We will consider CDR first and then breifly see how it is different from the Essential Climate Variables (ECVs).

1. Climate data Record (CDR)

Key characteristics of a CDR include:

• Long-term: CDRs should span at least 30 years to capture meaningful climate trends.
• High-quality: CDRs should undergo rigorous quality control procedures to ensure data accuracy and consistency.
• Consistent: CDRs should adhere to standardized data formats, protocols, and metadata to facilitate cross-comparison and analysis.
• Well-documented: CDRs should be accompanied by comprehensive documentation that describes the data collection methods, quality control procedures, and data processing steps.

Purposes of CDRs:

• Detecting climate change: CDRs provide the evidence needed to confirm the long-term trend of rising global temperatures and other climate changes.
• Characterizing climate variability: CDRs reveal patterns of climate variability, such as El Niño-Southern Oscillation (ENSO) and decadal climate oscillations.
• Understanding climate processes: CDRs help scientists understand the underlying mechanisms that drive climate change and variability.
• Evaluating climate models: CDRs are used to assess the accuracy and reliability of climate models, which are used to predict future climate conditions.
• Supporting decision-making: CDRs inform policy decisions related to climate adaptation, mitigation, and resource management.

Sources of Climate Data:

• Weather stations: These stations measure surface air temperature, precipitation, pressure, and other meteorological variables.
• Satellites: These platforms collect data on atmospheric composition, land surface characteristics, and ocean temperature and salinity.
• Tree rings: Tree rings provide a historical record of climate conditions, particularly temperature and precipitation.
• Ice cores: Ice cores extracted from glaciers and ice sheets contain trapped air bubbles that provide a record of atmospheric composition and temperature fluctuations over long periods.

Accessing Climate Data:

• National Oceanic and Atmospheric Administration (NOAA) Climate Data Online (CDO): This website provides access to a vast collection of climate data from NOAA and its partners.
• National Centers for Environmental Information (NCEI): This is the official website of NOAA's National Centers for Environmental Information, which is responsible for collecting, managing, and providing access to weather and climate data.
• European Centre for Medium-Range Weather Forecasts (ECMWF): This is an independent intergovernmental organization that provides meteorological data and services to its 34 member states.
• Copernicus Climate Change Service (C3S): This is a service provided by the European Union's Copernicus Programme that provides climate data and information to support climate change research, policy, and adaptation.
• World Meteorological Organization (WMO) Global Climate Data Centre: This is the world's largest archive of climate data, maintained by the World Meteorological Organization.

2. Essential Climate Variables (ECVs)

Essential Climate Variables (ECVs) are a set of key climate indicators that provide a comprehensive understanding of the Earth's climate system. They are identified and defined by the Global Climate Observing System (GCOS), an international partnership of governments, scientific institutions, and organizations responsible for ensuring that the world has the essential climate data and information needed for climate-related decision-making.

ECVs are selected based on their importance for understanding, assessing, and responding to climate change. There are 913 official ECVs (page-3, 496 existing and 417 planned), representing various aspects of the atmosphere, land, ocean, cryosphere, and biosphere.

ECVs are identified based on the following criteria:

• Relevance: The variable is critical for characterizing the climate system and its changes.
• Feasibility: Observing or deriving the variable on a global scale is technically feasible using proven, scientifically understood methods.
• Cost effectiveness: Generating and archiving data on the variable is affordable, mainly relying on coordinated observing systems using proven technology, taking advantage where possible of historical datasets.

3. Derived Essential Climate Variable (ECV):

Derived Essential Climate Variable (ECV) climate products are climate products that are derived from FCDRs. They are used to provide more specific information about the Earth's climate, such as the average temperature or precipitation for a particular region.

Examples

1. Fundamental Climate Data Records (FCDRs):
   • Surface air temperature (SAT): The average temperature of the Earth's surface near the ground.
   • Precipitation: The amount of water that falls to the Earth's surface as rain, snow, hail, or other forms.
   • Clouds: The amount and type of clouds in the atmosphere.
   • Atmospheric composition (including greenhouse gases, aerosols, and ozone): The amounts and concentrations of greenhouse gases, aerosols, and ozone in the atmosphere.
   • Surface pressure: The average pressure of the Earth's atmosphere near the ground.
   • Surface albedo: Percentage of sunlight that is reflected back into space from the Earth's surface.
2. Essential Climate Variables (ECVs):
   • Sea surface temperature (SST): The average temperature of the Earth's ocean surface.
   • Sea level: Height of the Earth's surface relative to a reference point.
   • Ocean circulation: Movement of water in the Earth's ocean.
   • Ocean salinity: Amount of salt in the Earth's ocean.
   • Ice cover: Amount of ice on the Earth's surface.
   • Carbon fluxes: Amounts of carbon moved between the atmosphere, land, and ocean.
3. Derived Essential Climate Variable (ECV) climate products:
   • Average temperature: The average temperature for a particular region.
   • Precipitation extremes: The highest and lowest precipitation amounts for a particular region.
   • Sea ice extent: The area of sea ice cover.
   • Ocean acidification: Increase in acidity of the Earth's ocean due to the absorption of carbon dioxide from the atmosphere.
   • Vegetation health: Condition of vegetation on the Earth's surface.

ECV Inventory

The ECV Inventory is a comprehensive database of climate data records that is maintained by the Coordination Group of Meteorological Satellites (CGMS) and the Committee for Earth Observation Satellites (CEOS). It is the primary repository of information about the availability, quality, and accessibility of data for the Essential Climate Variables (ECVs), which are key indicators of the Earth's climate system.

The ECV Inventory provides a wealth of information about climate data records, including:

• ECVs covered: The inventory lists all of the ECVs and the data records that are available for each ECV.
• Data sources: The inventory lists the different sources of data for each ECV, including satellites, ground-based instruments, and other sources.
• Spatial coverage: The inventory indicates the spatial coverage of each data record, including the latitude and longitude ranges, the altitude ranges, and the surface types covered.
• Temporal coverage: The inventory indicates the temporal coverage of each data record, including the start and end dates, the temporal resolution, and the data quality.
• Data quality: The inventory provides information about the quality of each data record, including the data sources, the processing methods, and the data validation procedures.
• Data access: The inventory provides information about how to access each data record, including the data providers, the data formats, and the access protocols.

The ECV Inventory is a valuable tool for researchers, policymakers, and other users of climate data. It can be used to:

• Identify data gaps: The inventory can be used to identify gaps in the availability of data for specific ECVs or in specific regions of the Earth.
• Compare data sources: The inventory can be used to compare the different data sources for a particular ECV and to assess their relative strengths and weaknesses.
• Plan data acquisition: The inventory can be used to plan future data acquisition activities and to identify the most appropriate data sources for specific projects.
• Evaluate data quality: The inventory can be used to evaluate the quality of existing data records and to identify data records that may be contaminated or unreliable.
• Make informed decisions: The inventory can be used to make informed decisions about climate research, policy, and adaptation.

The ECV Inventory is an essential resource for anyone working with climate data. It is a dynamic resource that is updated regularly to reflect the latest information about climate data availability.

Gap analysis

The gap analysis is a process of identifying and quantifying the gaps in the availability of Essential Climate Variables (ECVs) that can be best observed from space. This analysis is based on the ECV Inventory, which is a comprehensive database of climate data records from various sources.

The gap analysis identifies gaps in terms of:

• ECVs: The analysis identifies which ECVs are not adequately covered by existing data records.
• Spatial coverage: The analysis identifies which regions of the Earth are not adequately covered by existing data records.
• Temporal coverage: The analysis identifies which time periods are not adequately covered by existing data records.
• Data quality: The analysis identifies which data records are of insufficient quality for climate monitoring and research

Once the gaps have been identified, the WGClimate develops a coordinated action plan to address them. This plan includes:

1. Prioritizing ECVs: The WGClimate prioritizes the ECVs that need to be filled most urgently.
2. Identifying new data sources: The WGClimate identifies new data sources that can be used to fill the gaps.
3. Improving data access: The WGClimate works to improve the accessibility of existing data records.
4. Developing new data processing methods: The WGClimate develops new data processing methods to improve the quality of existing data records.

The gap analysis is an important tool for the WGClimate to ensure that the space-based architecture for climate monitoring is meeting the needs of the Global Climate Observing System (GCOS). By identifying and addressing the gaps in the availability of ECVs, the WGClimate can help to ensure that we have the data we need to understand, assess, and respond to climate change.

EUMESAT and it's role in providing climate data

References

1. Intergovernmental Panel on Climate Change
2. United Nations Framework Convention on Climate Change
3. Climate Action Tracker
4. The Climate Reality Project
5. 350.org
6. Glossary: Random, systematic, Structured random, and correlated data; Harmonisation, Traceability and Uncertainity, Georectification