G5.11 Non-operational provision of fiducial reference-measurement data and some satellite-derived products reduces their utility for monitoring and applications

Gap abstract: 

Copernicus Services, including the Climate Change Service (C3S), will provide information in close to real time using global and regional reanalysis outputs, as well as satellite L2 products. These outputs are not always consistent with their own climatology, because input data are not produced with the same quality at real-time as they are in elaborated climate data records. The availability of so-called "Climate Data Record Interim Products" would remedy this problem by producing products with as high as possible consistency with the climatology, being based on automated satellite inter-calibration and careful quality control. These types of data records are emerging from operational satellite agencies, but lacks optimal means for validation due to non-availability of many non-satellite reference measurements in close to real-time. 

Part I Gap description

Primary gap type: 
  • Governance (missing documentation, cooperation etc.)
Secondary gap type: 
  • Technical (missing tools, formats etc.)
ECVs impacted: 
  • Temperature,Water vapour, Ozone, Aerosols, Carbon Dioxide, Methane
User category/Application area impacted: 
  • Operational services and service development (meteorological services, environmental services, Copernicus Climate Change Service (C3S) and Atmospheric Monitoring Service (CAMS), operational data assimilation development, etc.)
  • International (collaborative) frameworks and bodies (space agencies, EU institutions, WMO programmes/frameworks etc.)
  • Climate research (research groups working on development, validation and improvement of ECV Climate Data Records)
Non-satellite instrument techniques involved: 
  • Independent of instrument technique
  • Gap 1.10 where the remedy of it would enable the networks of reference measurements with better geographical distribution that can become candidate for operational quality control and data dissemination.

    The remedies of Gap 1.10 and this gap can be realised in parallel. 

Detailed description: 

Copernicus Services, including the Climate Change Service, will provide information in close to real-time using global and regional reanalysis outputs, as well as satellite-derived products. For the validation of these products, both delivered with high timeliness, it is essential to have non-satellite reference measurements available for use in near-real-time, which is rarely the case today. There is a need to operationalise quality control and delivery of such data in the future to realise the potential benefits that fiducial reference measurements with characterised uncertainty offer.

Currently, many reference measurements are provided with specific delays due to requirements for certain quality-control measures to be applied. But in many other cases, delayed mode provision relates solely to network data policies and / or to data transmission protocols. The usage scenario for a Virtual Observatory within a Copernicus Service would likely need a close to real time availability of reference quality data streams to enable the assessment of very recent satellite-data products and the close to real time performed reanalysis. If the quality analysis and data provision for non-satellite fiducial reference measurements cannot be operationalised, leading to faster delivery, quality assessments of Copernicus products at short time scales shall remain of limited nature, reducing the value of the data for applications.

In addition, the timely operational delivery of satellite Climate Data Record Interim Level 2 products that are consistent with their long-term climatology also needs to be fostered to improve close to real-time reanalysis products and their validation. The validation of the Interim products could enhance the needs for non-satellite reference measurements as part of an operational validation set up.

Operational space missions or space instruments impacted: 
  • Independent of specific space mission or space instruments
Validation aspects addressed: 
  • Other:
The gap addresses the timeliness of validation that is needed for close to real time outputs of Copernicus Services.

Part II Benefits to resolution and risks to non-resolution

Identified benefitUser category/Application area benefittedProbability of benefit being realisedImpacts
Operational quality control and delivery of non-satellite reference measurements would allow for better characterisation of satellite and reanalysis products offered in close to real time.
This would most likely generate a higher demand for operationally produced reference measurements where the operational delivery requires also a sustained funding of the needed measurement devices and associated data services.
  • All users and application areas will benefit from it
  • Medium
Quality analysis for time-critical services of Copernicus could be significantly increased by providing reference measurements closer to real time.
Operational production of L2 Climate Data Record Interim satellite products would allow for more consistent reanalysis outputs and its validation.
  • All users and application areas will benefit from it
  • Medium
Quality analysis for time-critical services of Copernicus could be significantly increased by providing CDR Interim L2 products for assimilation and validation of reanalysis. The validation of such products requires the first benefit to be realised.
Identified riskUser category/Application area at riskProbability of risk being realisedImpacts
If the remedy on non-satellite reference measurements is not started, the use of non-satellite reference measurements remains limited.
  • All users and application areas will suffer from it.
  • Medium
Reference measurements may play only a minor role in the validation of Copernicus service outputs with potential long-term consequences for the network maintenance. This also applies to their use in the validation of emerging CDR Interim L2 products.
If the remedy on the satellite CDR Interim is not started, reanalysis outputs and other Copernicus satellite-based products suffer from temporal inconsistencies.
  • All users and application areas will suffer from it.
  • Medium
Quality assurance for CDR Interim L2 products would be far from optimal and financial support of reference-measurement systems may fade also endangering the validation of long-term data records.

Part III Gap remedies

Gap remedies: 

Remedy 1: Operationalise processing and delivery for non-satellite reference measurements and satellite CDR Interim L2 products.

Primary gap remedy type: 
Secondary gap remedy type: 
Proposed remedy description: 

A first step would be to assess the current procedures for quality control and delivery mechanism for non-satellite reference measurements, and to work out a proposal to further automate them. Depending on the needs, specific projects could be established to operationalise the processes and associated software. The dissemination of such data could be included into operational dissemination mechanisms used for operational data provisions such as over the WMO Information System.

In addition, entities producing GCOS ECV climate data records from satellite measurements should be encouraged to develop a mechanism that continues the data processing by keeping high consistency with the produced CDR. This involves automated inter-satellite calibration for input data to retrieval schemes and a strongly automated quality control, using non-satellite reference measurements that produces statistics in particular related to the temporal consistency with the long term CDR, e.g., stability and trend estimates with uncertainty. Such data shall be disseminated with high timeliness (~2-3 days delay). 


The remedy has the potential to significantly increase the use of non-satellite fiducial reference data in Copernicus Services. The operational character of quality control and delivery mechanism for such data and their subsequent operational use would potentially lead to a funding of measurement systems from operational sources that would sustain the measurement systems and associated data services rather long-term. This could be realised in conjunction with the already emerging generation of CDR Interim L2 products that need reliable reference measurements for their validation, which may increase the chance for funding. 

Measurable outcome of success: 

Close to real-time availability of non-satellite reference measurements and their use in the continuation of GCOS ECV climate data records with high timeliness to Copernicus Services. 

Expected viability for the outcome of success: 
  • Medium
  • High
Scale of work: 
  • Programmatic multi-year, multi-institution activity
Time bound to remedy: 
  • Less than 10 years
Indicative cost estimate (investment): 
  • Very high cost (> 10 million)
Indicative cost estimate (exploitation): 
  • Yes
Potential actors: 
  • Copernicus funding
  • National funding agencies
  • National Meteorological Services
  • ESA, EUMETSAT or other space agency
  • SMEs/industry