...

Expand
title Click here to expand the list of related documents (D1-D4D6)
Reference ID Document D1 Product Validation and Intercomparison Report (PVIR), v6.1. ESA Cloud_cci. https://climate.esa.int/media/documents/Cloud_Product-Validation-and-Intercomparison-Report-PVIR_v6.0.pdf Last accessed on 16/05/2023 D2 Algorithm Theoretical Basis Document, v.6.2. ESA Cloud_cci. https://climate.esa.int/media/documents/Cloud_Algorithm-Theoretical-Baseline-Document-ATBD_v6.2.pdf Last accessed on 16/05/2023 D3 Karlsson, K.-G. et al, (2023) C3S Surface Radiation Budget  CDRs releases until 2021: Target Requirements and Gap Analysis Document. Copernicus Climate Change Service. Document ref. C3S2_D312a_Lot1.3.1.1-2021_TRGAD-SRB_v1.1 SRB: Target Requirements and Gap Analysis Document Last accessed on 16/05/2023 D4 Thomas, G. (2023) C3S Surface Radiation Budget Service: Algorithm Theoretical Basis Document. Copernicus Climate Change Service, Document ref. C3S2_D312a_Lot1.2.3.3-v4.0_202301_ATBD_CCISurfaceRadiationBudget_v1.2 SRB CCI-ICDR: Algorithm Theoretical Basis Document (ATBD) Last accessed on 16/05/2023

Acronyms

D5 Meirink, J.F., et al, (2023) C3S cross ECV document Service: Key Performance Indicators (KPIs). Copernicus Climate Change Service, Document ref. C3S2_D312a_Lot1.3.7.1_202303_Unified_KPI_Approach_v1.0 Key Performance Indicators (KPIs) Last accessed: 23.08.2023 D6 Carboni, E., Thomas, G. (2022) C3S Surface Radiation Budget Service: Product Quality Assurance Document. Copernicus Climate Change Service, Document ref. C3S2_D312a_Lot1.1.3.1-v4.0_202207_PQAD_CCISurfaceRadiationBudget_v1.0 SRB CCI ICDR: Product Quality Assurance Document Last accessed on 31/05/2023

Acronyms

Expand
title Click here to expand the list of acronyms
Acronym Definition AATSR Advanced Along-Track Scanning Radiometer ATBD Algorithm Theoretical Basis Document ATSR Along-Track Scanning Radiometer bc-RMSE Bias Corrected Root Mean Squared Error BOA Bottom of the Atmosphere BSRN Baseline Surface Radiation Network C3S Copernicus Climate Change Service CC4CL Community Cloud retrieval for Climate CCI Climate Change Initiative CDR Climate Data Record CERES Clouds and Earth Radiation Energy System EBAF Energy Balanced and Filled ECV Essential Climate Variable ENVISAT Environmental Satellite ERS European Research Satellite ESA European Space Agency GCOS Global Climate Observing System ICDR Interim Climate Data Record ORAC Optimal Retrieval of Aerosol and Cloud RAL Rutherford Appleton Laboratory SAL Surface Albedo SDL Surface Downwelling Longwave
Expand
title Click here to expand the list of acronyms
Acronym Definition AATSR Advanced Along-Track Scanning Radiometer ATBD Algorithm Theoretical Basis Document ATSR Along-Track Scanning Radiometer bc-RMSE Bias Corrected Root Mean Squared Error BOA Bottom of the Atmosphere BSRN Baseline Surface Radiation Network C3S Copernicus Climate Change Service CC4CL Community Cloud retrieval for Climate CCI Climate Change Initiative CDR Climate Data Record CERES Clouds and Earth Radiation Energy System EBAF Energy Balanced and Filled ECV Essential Climate Variable ENVISAT Environmental Satellite ERS European Research Satellite ESA European Space Agency GCOS Global Climate Observing System ICDR Interim Climate Data Record ORAC Optimal Retrieval of Aerosol and Cloud RAL Rutherford Appleton Laboratory SAL Surface Albedo SDL Surface Downwelling Longwave radiation SIS Surface Incoming Shortwave radiation SLSTR Sea and Land Surface Temperature Radiometers SNL Surface Net Longwave radiation SNS Surface Net Shortwave radiation SOL Surface Outgoing Longwave radiation SRB Surface Radiation Budget SRS Surface Reflected Shortwave radiation STFC Science and Technology Facilities Council TCDR Thematic Climate Data Record TOA Top of the Atmosphere

...

Expand
title Click here to expand the list of tables
Table 1-1: Summary of methodologies used to estimate the accuracies, for TCDR and ICDR datasets. Table 2-1: Summary of the accuracy of the Surface Radiation Budget dataset. Table 43-1: Summary of KPI results with 2.5 and 97.5 percentiles and number of ICDR months within the range Table 4-1: GCOS targets for Earth GCOS targets for Surface Radiation Budget ECVs and TCDR CDR values.

List of figures

Expand
title Click here to expand the list of figures
Figure 2-1: Results from [D1]; Top: Validation results for Cloud_cci surface incoming shortwave (SIS) flux using BSRN as a reference. Bottom: Bias for each ground station. Figure 2-2: Results from [D1]; Top: Validation results for Cloud_cci surface downwelling longwave (SDL) flux using BSRN as a reference. Bottom: Bias for each ground station. Figure 2-3: SRS, SOL, SIS and SDL values from SLSTR (ICDR dataset) for March 2017. Figure 2-4: SRS, SOL, SIS and SDL values from CERES dataset for March 2017.

General definitions

The “CCI product family” Climate Data Record (CDR) consists of two parts. The ATSR2-AATSR Surface Radiation Budget CDR is formed by a TCDR brokered from the ESA Cloud_cci project and an ICDR derived from the Sea and Land Surface Temperature Radiometer (SLSTR) on board of Sentinel-3A and -B. ICDR uses the same processing and infrastructure as the TCDR. Both TCDR and ICDR data have been produced by STFC RAL Space.

...

Stability: The variation of the bias over a multi-annual time period

Anchor
table1 table1

Table 1: Summary of variables and definitions

Anchor
table2 table2

Table 2: Definition of processing levels

Anchor
table3 table3

Table 3: Definition of various technical terms used in the document

Scope of the document

This document provides a description of the product validation results for the Climate Data Record (CDR) of the Essential Climate Variable (ECV) Surface Radiation Budget. This CDR comprises inputs from two sources: (i) brokered products from the Cloud Climate Change Initiative (ESA’s Cloud_cci), namely those coming from processing of the Advanced Along-Track Scanning Radiometer (A)ATSR) data and (ii) those produced under this contract for the Climate Data Store, specifically those coming from processing of the Sea and Land Surface Temperature Radiometers (SLSTR).

...

Anchor
table1_1 table1_1

Table 1-1: Summary of methodologies used to estimate the accuracies, for TCDR and ICDR datasets.

The Product Validation and Intercomparison Report [D1] includes the validation and intercomparison of the TCDR Surface Radiation Budget versus the CERES satellite dataset. The same methodology is used for the ICDR.

Info
icon false
1 Please find more information on the reference data on [D1]: BSRN (Annex A.5) and CERES (A.6)

Anchor
validation validation

2. Validation results

The validation results for the TCDR products are presented and described in detail in [D1], sections 3.3.2, 5.3 and 5.4. In this document, a summary highlighting the main results is presented.  Only SIS and SDL in the TCDR product are validated with BSRN.   All   All other properties (including SIS and SDL in the ICDR) are compared with CERES. The evaluation with CERES is considered to be a comparison because the CERES surface radiation dataset has a similar accuracy to the CDR dataset.

Anchor
table2_1 table2_1

Table 2-1: Summary of the accuracy of the Surface Radiation Budget dataset. The ‘bold’ accuracies come from direct validation with a ground measurement network (BSRN), the others come from the intercomparison with similar datasets (CERES) or with an uncertainty propagation. ICDR values are obtained from data between January 2017 and December 2021 for SLSTR-A and between October 2018 and December 2021 for SLSTR-B.

 The ICDR data of SIS, SRS, SOL and SDL are compared with CERES, using the methodology described in [D1] section 5.3 and 5.4, and results are presented here in section 2.2.

...

The resulting global mean accuracy for the SRB is 36 W/m² for TCDR, 14 W/m² , 17 W/m² and 18 W/m² for ICDR SLSTR-A , B and A+B respectively.

3. Application(

...

s) specific assessments

In addition to the extensive product validation (see chapter 2 for results and chapter 2/3 in [D6] for validation methodology) a second assessment is introduced to evaluate the Interim Climate Data Record (ICDR) against the Thematic Climate Data Record (TCDR) in terms of consistency. Since frequent ICDR deliveries make detailed validation not feasible, a consistency check against the deeply validated TCDR is used as an indication of quality. This is done by a comparison of the following two evaluations:

• TCDR against a stable, long-term and independent reference dataset
• ICDR against the same stable, long-term and independent reference dataset

The evaluation method is generated to detect differences in the ICDR performance in a quantitative, binary way with so called Key Performance Indicators. The general method is outlined in [D5] chapter 3. The same difference between TCDR/ICDR and the reference dataset would lead to the conclusion that TCDR and ICDR have the same quality (key performance is "good"). Variations or trends in the differences (TCDR/ICDR against reference) would require a further investigation to analyze the reasons. The key performance would be marked as "bad". The binary decision whether the key performance is good or bad is made in a statistical way by a hypotheses test (binomial test). Based on the TCDR/reference comparison (global means, monthly or daily means) a range is defined with 95% of the differences are within. This range (2.5 and 97.5 percentile) is used for the ICDR/reference comparison to check whether the values are in or out of the range. The results could be the following:

• All or a sufficient high number of ICDR/reference differences lies within the range defined by the TCDR/reference comparison: Key performance of the ICDR is "good"
• A smaller number of ICDR/reference differences is within the pre-defined range: Key performance of the ICDR is "bad"

3.1 Results

The results of the KPI test are summarized in Table 3-1.

Anchor
table3_1 table3_1

Table 3-1: Summary of KPI results with 2.5 and 97.5 percentiles and number of ICDR months within the range. Colors green or red mark the results of the binomial tests as good or bad, respectively.

Percentiles were calculated based on the comparison of the TCDR using the Advanced Along Track Scanning Radiometer (AATSR) instrument against CERES as reference dataset for the variables Surface Incoming Shortwave Radiation (SIS), Surface Reflected Shortwave Radiation (SRS), Surface Outgoing Longwave Radiation (SOL) and Surface Downwelling Longwave Radiation (SDL). Percentiles were based on the time from 2002-2012 with monthly means and applied to the ICDR from 01/2017 (10/2018) to 06/2022 for Sentinel-3A (Sentinel-3B and merged product Sentinel-3A+B) based on measurements of the Sea and Land Surface Temperature Radiometer (SLSTR).

Most of the ICDR months are outside the TCDR-based KPI limits and leading to “bad” KPI tests. Therefore, the ICDR is not stable in relation to the TCDR. This is due to multiple reasons starting with the fact of a five year gap (2012-2016) between TCDR and ICDR. In addition, TCDR and ICDR are based on different instruments with SLSTR on Sentinel-3 and (A)ATSR/ATSR-2 on Envisat/ERS-2, respectively. Differences occur due to a lower bias between ICDR and reference dataset and a subtraction of the monthly means (based on the TCDR) to remove the annual cycle leads to values outside of the KPI range (see method in [D5], chapter 3.2.2). Please note that significant changes between 01/2017 - 12/2020 and 01/2017 - 12/2021 are due to bugfixesThis section is not applicable. There are no additional application specific assessments known since the dataset has just been published.

4. Compliance with user requirements

...

Anchor
table4_1 table4_1

Table 4-1: GCOS targets for Earth Radiation Budget ECVs and CDR values. TCDR values taken from Table 5-4 and Table 5-5 in [D1].

 Known limitations [From D1 table 7.1]:

...

Anchor
reference reference

References

n/a

Info
icon false
This document has been produced with funding by the European Union in the context of the Copernicus Climate Change Service (C3S) .The activities leading to these results have been contracted , operated by the European Centre for Medium-Range Weather Forecasts , operator of C3S on behalf of on the European Union ( Delegation Agreement signed on 11/11/2014 and Contribution Agreement signed on 22/07/2021). All information in this document is provided "as is" and no guarantee or of 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.

Related articles

Content by Label
showLabels false max 5 spaces CKB showSpace false sort modified reverse true type page cql label in ("ecv","surface_radiation_budget") and type = "page" and space = "CKB" labels era-interim