...

Contributors: G.E. Thomas (UKRI-STFC RAL Space) and R. Shevchuk (Brockmann Consult)

Issued by: STFC RAL Space (UKRI-STFC) / Gareth Thomas and Brockmann Consult / Roman Shevchuk

Date: 26/05/2023 12 Jan 2024 

Ref: C3S2_D312a_Lot1.2.1.4-v4.0_2023056_202407_PUGS_ECV_CCICloudPropertiesCLD_SLSTR_v1.2_final

Official reference number service contract: 2021/C3S2_312a_Lot1_DWD/SC1

...

Easy Heading Macro
navigationExpandOption collapse-all-but-headings-1

Anchor
history_of_modifications history_of_modifications

History of modifications

Expand
title Click here to expand the history of modifications
Ch. 2.3.2 Version Date Description of modification Chapters / Sections V1.0 28/1105/20222024 Brought forward from previous phase of C3S. Updated to include description of merged Sentinel-3A and -3B level 3 products (RAL) and addition of further dataset extension (Brockmann Consult) All V1.1 0625/0307/20232024 Implementation of the comments from the review teamUpdated to address reviewer's comments All v1.2 2629/0507/20232024 Addition of chapter 2.3.2 to list gaps and anomalies Implementation of the comments from the review team and finalization for publication All

Anchor
list_of_datasets list_of_datasets

List of datasets covered by this document

Expand
title Click here to expand the list of datasets covered by this document
Deliverable ID Product title Product type (CDR, ICDR) Version number Delivery date D3.3.17-v3.0 ECV Cloud properties brokered from ESA's Properties brokered from ESA’s Cloud_cci ATSR-AATSRv3 AATSR v3 dataset CDRTCDR V3.0 30/04/2020 D3.3.18-v3.x.1.1 P3-P6 ECV Cloud properties Properties derived from SLSTR ICDR V3.1.1 30/11/2020 - 30 26/ 09 08/2021 D2.1.1 - P1/2 D2.1.3-P1-P2 ECV Cloud Properties derived from SLSTR ICDR V3.1.1V4.0 3130/05/2022 - onward

...

– 03/05/2023 D2.1.3 P1 ECV Cloud Properties derived from SLSTR ICDR V4.0 03/05/2023 D2.9.2 ECV Cloud Properties derived from SLSTR extension ICDR V4.0 31/05/2024

Anchor
related_documents related_documents

...

Related documents

Expand
title Click here to expand the related documents (D1-D5D6)
Reference ID Document D1 Thomas, G. (SFTC-RAL), 2023) . C3S Cloud Properties Service: Algorithm Theoretical Basis Document. Copernicus Climate Change Service, Document ref. C3S2_D312a_Lot1.2.1.3-v4.0_202301_ATBD_CCICloudProperties_v1.2 CP CCI ICDR: Algorithm Theoretical Basis Document Last accessed on 1629/0504/20232024 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 1629/0504/20232024 D3 Product User Guide, v5.1. ESA Cloud_cci, https://climate.esa.int/media/documents/Cloud_Product-User-Guide-PUG_v5.1.pdf Last accessed on 1629/0504/20232024 D4 Comprehensive Error Characterisation Report, v4.1. ESA Cloud_cci. https://climate.esa.int/media/documents/Cloud_Comprehensive-Error-Characterisation-Report-CECR_v4.1.pdf Last accessed on 1629/0504/20232024 D5 Karlsson, K.-G., et al., (2023) C3S Cloud Properties  CDRs releases until 2021Service: Target Requirements and Gap Analysis Document. Copernicus Climate Change Service.  Document ref. C3S2_D312a_Lot1.3.1.1-20212022_TRGAD-CLD_v1.1 CP: Target Requirements and Gap Analysis Document Last accessed on 1629/0504/20232024

Acronyms

D6 N. Fomferra, M. Böttcher, M. Zühlke, C. Brockmann and E. Kwiatkowska, "Calvalus: Full-mission EO cal/val, processing and exploitation services," 2012 IEEE International Geoscience and Remote Sensing Symposium, 2012, pp. 5278-5281, doi: 10.1109/IGARSS.2012.6352418. https://ieeexplore.ieee.org/document/6352418

Anchor
acronyms acronyms

Acronyms

Expand
title Click here to expand the list of acronyms
Acronym Definition AATSR Advanced Along-Track Scanning Radiometer (A)ATSR Shorthand for the Along-Track Scanning Radiometer series of instruments. In the current context, refers to ATSR-2 and AATSR. ATBD Algorithm Theoretical Basis Document ATSR-1, -2 Along Track Scanning Radiometer AVHRR Advanced Very High Resolution Radiometer BC Brockmann Consult C3S Copernicus Climate Change Service CC4CL Community Cloud for CLimate CCI (ESA) Climate Change Initiative CDR Climate Data Record CDS Climate Data Store CER Cloud Particle Effective Radius CFC Cloud Fractional
Expand
title Click here to expand the list of acronyms
Acronym Definition AATSR Advanced Along-Track Scanning Radiometer (A)ATSR Shorthand for the Along-Track Scanning Radiometer series of instruments. In the current context, refers to ATSR-2 and AATSR. ATBD Algorithm Theoretical Basis Document ATSR-1, -2 Along Track Scanning Radiometer AVHRR Advanced Very High Resolution Radiometer C3S Copernicus Climate Change Service CC4CL Community Cloud for CLimate CCI (ESA) Climate Change Initiative CDR Climate Data Record CDS Climate Data Store CER Cloud Particle Effective Radius CFC Cloud Fractional Cover COT Clout Optical Thickness CPH Cloud Phase CTH Cloud Top Height CTP Cloud Top Pressure CTT Clout Top Temperature DARD Data Access Requirements Document DWD Deutscher Wetterdienst ECV Essential Climate Variable ENVISAT (the) Environmental Satellite ERS-2 Environmental Research Satellite ESA European Space Agency FCDR Fundamental Climate Data Record GCOS Global Climate Observing System ICDR Interim Climate Data Record IWP Cloud Ice Water Path LWP Cloud Liquid Water Path MODIS Moderate Resolution Imaging Spectroradiometer NIR Near-Infrared ORAC Optimal Retrieval of Aerosol and Cloud PUG Product User Guide RAL Rutherford Appleton Laboratory SLSTR Sea and Land Surface Temperature Radiometer STFC Science and Technology Facilities Council TCDR Thematic Climate Data Record TRGAD Target Requirements and Gap Analysis Document UKRI UK Research and Innovation WMO World Meteorological Organisation

List of tables

Anchor
list_of_tables list_of_tables

List of tables

Expand
title Click here to expand the list of tables
Table 1-1: GCOS targets for cloud properties ECVs Table 1-2: Cloud properties included in Cloud_cci TCDR and SLSTR ICDR monthly products Table 2-1: GCOS targets for cloud ECVs Table 2-2: Cloud properties included in Cloud_cci TCDR and SLSTR ICDR daily products Table 2-3: Summary of gaps and anomalies for each satellite

...

Anchor
list_of_figures list_of_figures

List of figures

Expand
title Click here to expand the list of figures
Figure 1-1: Overview of data producers, satellites, time coverages and grids for the ICDRs.

Anchor
general_definitions general_definitions

General definitions

Table 1: Summary of variables and definitions

Table 2: Definition of processing levels

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

Scope of the document

Anchor
scope_of_the_document scope_of_the_document

Scope of the document

This Product User Guide and Specification (PUGS) document is associated with the Climate Data Store (CDS) catalogue entry: Cloud properties global This Product User Guide and Specification (PUGS) document is associated with the Climate Data Store (CDS) catalogue entry: Cloud properties global gridded monthly and daily data from 1982 1979 to present derived from satellite observations. This Climate Data Record (CDR) comprises inputs from two three 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 (data (also named TCDR (Thematic Climate Data Record)), and two Interim Climate Data Records (ICDR) extensions namely (ii) those produced under this contract for the CDS, specifically those coming from processing of the Sea and Land Surface Temperature Radiometers (SLSTR) . Both CDRs are produced by Rutherford Appleton Laboratory (RAL) Space using the Optimal Retrieval of Aerosol and Cloud (ORAC) iii) those produced under this contract for the CDS, specifically those coming from processing of the SLSTR by Brockmann Consult (BC).

Both of the ICDRs mentioned above are produced using the Optimal Retrieval of Aerosol and Cloud (ORAC) algorithm, using the Community Cloud for Climate (CC4CL) processor under the ESA Cloud_cci project.  One ICDR was produced by Rutherford Appleton Laboratory (RAL) Space for the period 01/2017 to 06/2022 and the other ICDR by Brockmann Consult (BC) for the period 07/2022 to 12/2023.

This document provides information on how to use these products and it . It is not part of the official CCI documentation, but produced only in the scope of the brokering to the CDS.

Anchor
executive_summary executive_summary

Executive summary

The ESA Climate Change Initiative (CCI) Cloud Properties Climate Data Record (CDR) is a brokered product from the ESA Cloud_cci project, while the extension Interim CDR (ICDR) produced from the Sea and Land Surface Temperature Radiometers (SLSTR) is produced specifically for C3S. The product is generated by RAL Space, using the Community Cloud for Climate (CC4CL) processor, based on the Optimal Retrieval of Aerosol and Cloud (ORAC) algorithm. The ICDR product was generated by RAL Space up to 06/2022 and by BC for the period 07/2022 to 12/2023.

The Cloud_cci dataset comprises 17 years (1995-2012) of satellite-based measurements derived from the Along Track Scanning Radiometers (ATSR-2 and AATSR) onboard the ESA second European Research Satellite (ERS-2) and ENVISAT. This CDR TCDR is partnered with the ICDR produced from the Sentinel-3 Sea and Land Surface Temperature Radiometers (SLSTR), beginning in 2017 (Sentinel-3A) and 2018 (Sentinel-3B), when data from each platform became available. In addition to the individual data from each platform, a merged product is provided from 10/2018 onwards.

The TCDR and ICDRs provide both The CDR provides level-3 data (monthly means) and level-2 (daily means) on a regular two grids: (1) regular equal angle global latitude-longitude grid (with a resolution of 0.5°× 0.5°) as well as level-2 data (daily means) on a regular and (2) regular equal area global latitude-longitude grid (with the second option solely for the merged product from 07/2022 onwards). An overview of the various data producers, satellites, grids and time coverages for the ICDRs is shown in section 1, Figure 1-1.

Both grids have a resolution of 0.1°×5°× 0.1°) and includes 5° for monthly means and 0.1°× 0.1° for the daily means. Both grids include these products: cloud fractional cover (CFC), cloud phase (water/ice), cloud optical thickness (COT), cloud particle effective radius (CER), cloud liquid/ice water path (LWP/IWP), and cloud-top pressure (CTP), height (CTH) and temperature (CTT).

These products are brokered to (in the case of (A)ATSR) or produced for the Climate Data Store (in the case of SLSTR) by the Copernicus Climate Change Services (C3S). The respective data products (daily and monthly means) are first described in terms of their input data and a brief overview of the algorithms is provided; their target requirements in the scope of C3S and achieved performances are given; relevant information for usage is provided. The latter comprises geographical grid specifications, the data format, naming conventions, and the acknowledgement policy.

Anchor
chapter1 chapter1

1. Cloud_cci global monthly cloud products

The Cloud_cci global monthly cloud properties product, version 3.0, is brokered to the CDS by the C3S from STFC RAL Space. The SLSTR ICDR until 06/2022, versions 3.1.1 and 4.0, is supplied to the CDS via the same route and uses the same processing software and infrastructure as the CDRTCDR. The SLSTR ICDR, version 4.0 from 07/2022 to 12/2023 is processed on BC infrastructure using the same processing software for Level-2, the additional grid version (equal area) was processed using the Calvalus aggregator for Level-3 step [D6]. Although the format of the brokered data products differs from the official CCI products, the intellectual property rights remain with the Cloud_cci team. In detail, the official daily and monthly files from Cloud_cci contain more than 180 variables, but the specified C3S format splits them into separate parts per ECV. That way, each file has a reduced data amount as well as an increased usability. The landing page for the official CCI products is https://climate.esa.int/en/projects/cloud/. Detailed information on the cloud products and their use are outlined in the CCI Product User Guide [D3].

The product provides estimates The product provides estimates of monthly mean global cloud properties over land and ocean from the Along Track Scanning Radiometer ((A)ATSR) series of satellite sensors, on a 0.5°×0.5° latitude-longitude grid from mid-1995 until early 2012. The SLSTR based ICDR extends the coverage, with a five-year gap, from 2017 onwards and is only available through the CDS. Version 3.x 1.1 of the ICDR provides data from a single SLSTR (flying on board either Sentinel-3a or -3b), while version 4.0 combines data from both SLSTR instruments into a single combined product (starting with the launch of the Sentinel-3b in late 2018). The processing of version 3.1.1 and 4.0 are is identical – the sole difference is whether the two instruments are treated separately or treated as a single data-stream.

...

All monthly means are provided on an equal angle projection. In addition, the product from 07/2022 onwards is provided on an equal area projection as well (see Figure 1-1 for an overview).

Image Added

Anchor
figure1-1 figure1-1

Figure 1-1: Overview of data producers, satellites, time coverages and grids for the ICDRs. Products above/below the horizontal black line are produced by RAL Space/Brockmann Consult (BC) respectively, while data from 07/2022 onwards is provided on two different grids.

1.1

Anchor
section1.1 section1.1

Product description

The Cloud_The Cloud_cci product brokered to the CDS consists of cloud properties derived from the (A)ATSR instruments; specifically:

...

The analysis algorithm applied in producing the Cloud_cci products is the Optimal Retrieval of Aerosol and Clouds (ORAC), while the overall data processing system used in the project is referred to as Community Cloud for Climate (CC4CL). The algorithm, processing chain and all input and auxiliary data are detailed described in the C3S ATBD [D1], Cloud_cci ATBD [D2], Sus et al. (2018) and McGarragh et al. (2018).

The brokered CDR TCDR is extended, with a five-year gap, from 2017 with an ICDR derived from the SLSTR instruments, which fly onboard the Copernicus operational Sentinel-3 satellites. From Since late 2018, a second Sentinel-3 platform is available, which doubles the spatial coverage of SLSTR and allows for nearly complete global coverage twice a day. The SLSTR product is produced using the same processing chain as the (A)ATSR CDR.TCDR.

Anchor
section1.2 section1.2

1.2 Target requirements

The target requirements for cloud observations are laid-out in the Target Requirements and Gap Analysis Document (TRGAD) [D5], but are summarised here. These requirements originate from the WMO Global Climate Observing System (GCOS) initiative, which defines and lays down targets for the observation of essential climate variables (ECVs). It should be noted that GCOS defines ideal targets for Earth observation systems, which are often not attainable using existing or historical observing systems. Table 1-1 provides an overview of the GCOS requirements for cloud properties.

Anchor
table1_-1 table1_-1

Table 1-1: GCOS targets for cloud properties ECVs. Note that the Cloud_cci doesn't meet the temporal requirements due to the nature of the satellite observations, but exceeds the spatial resolution and aims to achieve the uncertainty and stability requirements.

Anchor
section1.3 section1.3

1.3 Data usage information

Cloud_cci and SLSTR ICDR products are provided in NetCDF (version 4), which are compliant with the conventions CF 1.8 and the NASA Global Change Master Directory (GCMD) Science Keywords vocabulary. Filenames follow the structure:

C3S-312bL1-L3C-MONTHLY-CLOUD-INST_ORAC_EA_PLATFORM{}_YYYYMM{_}_fvVVV_fvV.V.nc,

where INST and PLATFORM refer to the instrument and platform from which data originates (either ATSR2 and ERS2, or AATSR and ENVISAT for the

...

TCDR, or SLSTR and Sentinel-3a or -3b for the ICDR), EA is added for the additional equal area grid and left out for the equal angle grid, and YYYYMM provides the year and month covered by the monthly mean product, and

...

V.V denotes the product version

...

.

...

Data are provided as monthly means of cloud properties, as described in Table 1-2, on a regular latitude-longitude grid, with a spacing of 0.5° in both dimensions (thus grid centres lie at -89.75°, -89.25°, -88.75°, …, 89.75° in latitude and -179.75°, -179.25°, -178.75°, …, 179.75° in longitude).

The list of cloud properties, the variable names used within the NetCDF data files and their units are given in Table 1-2.

Anchor
table1_-2 table1_-2

Table 1-2: Cloud properties included in Cloud_cci TCDR and SLSTR ICDR monthly products available through the CDS.

For lists and details of known issues and limitations of the data, the user is referred to the referenced ATBDs and papers in Section 1.1, as well as the TRGAD [D5]. In particular, it should be noted that the monthly mean is computed using data from sun-synchronous polar-orbiting satellites, with a relatively narrow swath. Thus, it cannot be considered a representation of the mean properties of clouds across the whole month for two reasons:

...

Info
icon false
1 At high latitudes temporal sampling becomes somewhat better, as adjacent orbits overlap.

...

Anchor
subsection1.3.1

...

subsection1.3.1

1.3.1 Uncertainties

The ORAC retrieval algorithm is an implementation of Optimal Estimation (Rodgers, 2000) and as such provides uncertainty estimates on all retrieved parameters, propagated from the uncertainty in the input satellite measurements (as well as any forward modelling error included in the uncertainty calculations). The propagation of the L2 uncertainty into L3 products, such as those brokered to the CDS, is not straight forward. Users should refer to the Cloud_cci Comprehensive Error Characterisation Report [D4].

...

3. Correlated uncertainty in value. If a the L2 pixels are assumed to be correlated with each other, the uncertainty in the resulting average can be calculated using: 

...

where σ²_std is the unweighted standard deviation about the mean and c is the correlation between the L2 pixels.

Anchor
chapter2 chapter2

2. Cloud_cci global daily cloud products

The Cloud_cci global daily cloud properties product, version 3.0, is brokered to the CDS by the C3S from STFC RAL Space. The SLSTR ICDR, versions 3.1.1 and 4.0 are supplied to the CDS via the same route and uses the same processing software and infrastructure as the CDRthe TCDR. The SLSTR ICDR, version 4.0 from 07/2022 to 12/2023 is processed on BC infrastructure using the same processing software for Level-2, the additional grid version (equal area) was processed using Calvalus aggregator for Level-3 step. Although the format of the brokered data products differs from the official Cloud_cci products, the intellectual property rights remain with the Cloud_cci team. In detail, the official daily and monthly files from Cloud_cci contain more than 180 variables, but the specified C3S format splits them into separated parts per ECV. That way, each file has a reduced data amount as well as an increased usability. The landing page for the official CCI products is https://climate.esa.int/en/projects/cloud/.

The product provides estimates of daily mean global cloud properties over land and ocean from the Along Track Scanning Radiometer ((A)ATSR) series of satellite sensors, on a 0.1°×0.1° latitude-longitude grid from mid-1995 until early 2012. The SLSTR based ICDR extends the coverage, with a five-year gap, from 2017 onwards and is only available through the CDS. Version 3.x of the ICDR provides data from a single SLSTR (flying on board either Sentinel-3a or -3b), while version 4.0 combines data from both SLSTR instruments into a single combined product (starting with the launch of the Sentinel-3b in late 2018). The processing of version 3.x and 4.0 are identical – the sole difference is whether the two instruments are treated separately or treated as a single data-stream.

...

All monthly means are provided on an equal angle projection. In addition, the product from 07/2022 onwards is provided on an equal area projection as well (see Figure 1-1 for an overview).

Anchor
section2.1 section2.1

2.1 Product description

The Cloud_cci product brokered to the CDS consists of cloud properties derived from the (A)ATSR instruments; specifically:

• ATSR-2, which flew on the second European Research Satellite (ERS-2) from June 1995 until January 2008. ERS-2 lost global coverage in June 2003, due to failure of the onboard data storage; Cloud_cci data do not extent extend beyond this date (thus providing approximately one-year of overlap with the succeeding AATSR product.
• Advanced-ATSR (AATSR), which flew on ENVISAT from May 2002 until the satellite’s failure in April 2012.

...

The analysis algorithm applied in producing the Cloud_cci products is the Optimal Retrieval of Aerosol and Clouds (ORAC), while the overall data processing system used in the project is referred to as Community Cloud for Climate (CC4CL), and these are detailed in the C3S ATBD [D1], Cloud_cci ATBD [D2], Sus et al. (2018) and McGarragh et al. (2018).

The brokered CDR TCDR is extended, with a five-year gap, from 2017 with an ICDR derived from the SLSTR instruments, which fly onboard the Copernicus operational Sentinel-3 satellites. From Since late 2018, a second Sentinel-3 platform is available, which doubles the spatial coverage of SLSTR and allows for nearly complete global coverage twice a day. The SLSTR product is produced using the same processing chain as the (A)ATSR CDR.TCDR.

Anchor
section2.2 section2.2

2.2 Target requirements

The target requirements for cloud observations are laid-out in the Target Requirements and Gap Analysis Document (TRGAD) [D5], but are summarised here. These requirements originate from the WMO Global Climate Observing System (GCOS) initiative, which defines and lays down targets for the observation of essential climate variables (ECVs). It should be noted that GCOS requirements are targets and defines ideal targets for Earth observation systems, which are often not attainable using existing or historical observing systems. Table 2-1 provides an overview of the GCOS requirements for cloud properties.

Anchor
table2_-1 table2_-1

Table 2-1: GCOS targets for cloud ECVs. Note that the Cloud_cci doesn't doesn’t meet the temporal requirements due to the nature of the satellite observations, but exceeds the spatial resolution and aims to achieve the uncertainty and stability requirements.

Anchor
section2.3 section2.3

2.3 Data usage information

Cloud_cci products are provided in NetCDF (version 4), which are compliant with the conventions CF 1.8 and the NASA Global Change Master Directory (GCMD) Science Keywords vocabulary. Filenames follow the structure:

C3S-312bL1-L3C-DAILY-CLOUD-INST_ORAC_EA_PLATFORM{}_YYYYMMDD{_}fvVVV{_}_ fvV.V.nc,

where INST and PLATFORM refer to the instrument and platform from which data originates (either ATSR2 and ERS2, or AATSR and ENVISAT for the CDRTCDR, or SLSTR and Sentinel-3a or -3b for the ICDR), YYYYMMDD EA is added for the additional equal area grid and left out for the equal angle grid, and YYYYMM provides the year , and month and day covered by the daily monthly mean product, and VVV V.V denotes the product version (3.0 for the TCDR, 3.1 for the ICDR).

Data are provided as daily means of cloud properties, as described in Table 2-2, on a regular latitude-longitude grid, with a spacing of 0.1° in both dimensions (thus grid centres lie at -89.95°, -89.85°, -89.75°, …, 89.95° in latitude and -179.95°, -179.85°, -179.75°, …, 179.95° in longitude).

Unlike the monthly product, the daily product separates the variables into day and night observations, stored in different variables within the product. In this context "day" “day” measurements are defined as those where the solar zenith angle is low enough that the solar reflectance can be used in the retrieval scheme. In the case of ORAC this means a solar zenith angle of θ0<80° . There are two main reasons for this approach:

...

The list of cloud properties, the variable names used within the NetCDF data files and their units are given in Table 2-2.

Anchor
table2_-2 table2_-2

Table 2-2: Cloud properties included in Cloud_cci TCDR and SLSTR ICDR daily products .available through the CDS.

For lists and details of known issues and limitations of the data, the user is referred to the referenced ATBDs and papers in Section 1.1.

Anchor
section2.3.1 section2.3.1

2.3.1 Uncertainties

The ORAC retrieval algorithm is an implementation of Optimal Estimation (Rodgers, 2000) and as such provides uncertainty estimates on all retrieved parameters, propagated from the uncertainty in the input satellite measurements (as well as any forward modelling error included in the uncertainty calculations). The propagation of the L2 uncertainty into L3 products, such as those brokered to the CDS, is not straight forward. Users should refer to the Cloud_cci Comprehensive Error Characterisation Report [D4].

Uncertainty and variability in the monthly daily mean cloud properties is expressed using three separate values, as described by Bennartz (2017, pers. comm.):

1. Standard deviation about the mean. This value is the unweighted standard deviation of the L2 retrieval values about the mean value reported for each L3 pixel.

...

where σ_i are the uncertainties of the  L2 N L2 pixels included in the average, and the <> indicates the mean value.

3. Correlated uncertainty in value. If a the L2 pixels are assumed to be correlated with each other, the uncertainty in the resulting average can be calculated using: 

...

where σ²_std  is the unweighted standard deviation about the mean and c is the correlation between the L2 pixels.

2.3.2 Gaps and anomalies

A small number of gaps occurs in the daily means of the dataset. These are due to maintenance reasons or outages of instruments. In addition, anomalies appear and lead to a number of days which should be treated with caution. Table 2-3 provides a list of days which are either not available or anomalous.

...

Sentinel-3A

...

Anchor
chapter3 chapter3

...

Sentinel-3B

...

3. Data access information

The original repository for the CCI formatted L3 data can be accessed through the Cloud_cci homepage https://climate.esa.int/en/projects/cloud/data/, as can all relevant documentation from the project. It should be noted that Cloud_cci L3 data is not in the same format as data brokered to the CDS, however the same L2 retrieval output was used to produce both products. In detail, the official daily and monthly files from Cloud_cci contain more than 180 variables, but the specified C3S format split them into separate parts per ECV. That way, each file has a reduced data amount as well as an increased usability.

Cloud_cci data should also be available through the ESA_cci data portal http://cci.esa.int/data, which provides online data mining, analysis and visualization tools for CCI data through the CCI Toolbox.

Only the brokered (A)ATSR based CDR TCDR is available through the ESA_cci data portal (original provider) as well as the CDS (brokered from CCI within the C3S Project), with SLSTR data being supplied only to the CDS.

3.1 Data access through CCI

Within C3S, the distribution will be through the CDS (https://cds.climate.copernicus.eu/) where documentation created for the inclusion of the data in the CDS, such as this PUGS, will be also provided.

...

only supplied by the CDS.

Anchor
section3.1 section3.1

3.1 Data access through the CDS

Within C3S, the distribution will be is through the CDS (https://cds.climate.copernicus.eu/) where documentation created for the inclusion of the data in the CDS, such as this PUGS, will be is also provided.

Anchor
section3.2 section3.2

3.

...

2 Product ordering process

You need to be registered and logged in to order products in the CDS. A login is provided upon registration, all products in the CDS are delivered free of charge.

Anchor

...

references

...

references

References

Bennartz, R., 2017: Error propagation in the generation of gridded satellite datasets, DWD Visiting Scientist Report.

...

Sus, O., M. Stengel, S. Stapelberg, G. McGarragh, C.A. Poulsen, A.C. Povey, C. Schlundt, G.E. Thomas, M. Christensen, S. Proud, M. Jerg, R.G. Grainger, R. Hollmann, 2018: The Community Cloud retrieval for Climate (CC4Cl) – Part 1: A framework applied to multiple satellite imaging sensors. Atmos. Meas. Tech., 11, 3373-3396, DOI: 10.5194/amt-11-3373-2018.

Info

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 on the European Union (Contribution Agreement signed on 22/07/2021). All information in this document is provided “as is” "as is" and no guarantee 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 author's view.

Anchor
related_articles related_articles

Related articles

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