About
Terrestrial vegetation plays a major role in the climate system through primary productivity by photosynthesis and respiration, recycling of precipitation, and soil formation. Two essential climate variables (ECVs) that describe the state of the vegetation are the Leaf Area Index (LAI) and fraction of incident surface solar radiation in the photosynthetically active region (0.4-0.7 μm) absorbed by vegetation (FAPAR). Consistent, global time series of LAI and FAPAR can provide insight into the dynamic role of vegetation in the Earth's climate.
The Leaf Area Index (LAI) of a plant canopy or ecosystem, defined as one half of the total leaf area per unit horizontal ground surface area, determines the size of the interface for exchange of energy (including radiation) and mass between the canopy and the atmosphere. It also partly controls photosynthesis and respiration. Monitoring its distribution and changes is important for assessing growth and vigour of vegetation on the planet.
FAPAR plays a critical role in assessing the primary productivity of canopies, the associated fixation of atmospheric carbon dioxide, and the energy balance of the surface. It is one of the main inputs of Light Use-Efficiency (LUE) models to estimate biomass production.
Objective
The objective of the project is to develop a dataset and a processing chain for global, multi-decadal time series of LAI and FAPAR that is both ready for operational use, and that has demonstrated added value for the climate science community.
In the project we aim for the following innovations:
Maximizing the use of EO data: The final data sets will cover the global land mass for the period 2000-2021 at 1 km and 300m and will be based on the optimal joint retrieval of the following sensors:
- SPOT4/VGT1 and SPOT5/VGT2
- Terra/MODIS and Aqua/MODIS
- ENVISAT/MERIS
- Metop-A/B/C-AVHRR
- PROBA-V
- Sentinel-3/OLCI
- VIIRS
Using an innovative retrieval algorithm: A computationally efficient radiative transfer model inversion will make synergistic use of multiple satellite missions possible. After atmospheric correction, a coupled model for soil, snow, vegetation model and residual atmospheric effects will be used. The algorithm enables the optimal use of available data in a time window, and the quantification of uncertainties of the product.
Maximising the use of validation data: The selected sites include the following locations for which ground data is available or which are representative of global conditions (see also Figure 4):
- Direct 2.1: 140 sites with ground data for specific campaigns, 2000-2021
- GBOV: 23 sites with multi-temporal ground data, 2013-2019
- AMMA: 13 sites with multi-temporal ground data, 2005-2015
- LANDVAL v1.1: 720 sites for product inter-comparison
- Sites defined by the Climate Research Group
Exploiting synergies with other ECVs: In two science studies the fitness of the data products will be evaluated for the modelling of light and water use efficiency, combined with other ECVs, and for the identification of the effects of temperature anomalies in time series. A feasibility study for the solar induced chlorophyll fluorescence (SIF) will investigate the possibilities of SIF as a complementary ECV.
The project is organised in 3 cycles, focusing the development of the algorithm using state of the art tools, improvements by the progressive inclusion of more sensor data, and stepping up towards operational use. Science studies with the data will run in parallel to assess the scientific value of the products.
Data
Vegetation Parameters Products
The VP CCI+ data sets will be made available via CEDA .
The figure below illustrates the general concept of the data sets produced during the three cycles of this project. It is organized with progressive inclusion of sensors, spatial and temporal coverage and resolution, with the dimensions of the test datasets (TDS) and climate research data packages (CRDP) illustrated. The initial emphasis is on the implementation of an innovative approach, gradually shifting towards selection and optimization for an operational context. The first cycle is distributed into an initial product validation and algorithm selection exercise, followed by the development of the baseline algorithm.
The data sets are further defined in the table below. The selected sites include the following locations for which ground data is available or which are representative of global conditions (see also Figure 4):
- Direct 2.1: 140 sites with ground data for specific campaigns, 2000-2021
- GBOV: 23 sites with multi-temporal ground data, 2013-2019
- AMMA: 13 sites with multi-temporal ground data, 2005-2015
- LANDVAL v1.1: 720 sites for product inter-comparison
- Sites defined by the CRG
The data sets are further defined in the table below.
Name | Cycle | Resolution | Sensors | ROI | Period |
---|---|---|---|---|---|
TDS-1 | 1 | 1000 m | SPOT4/5-VGT1/2, PROBA-V, Sentinel-3 OLCI | Selected sites | 2019 |
CRDP-1 | 1 | 1000 m | SPOT4/5-VGT1/2, PROBA-V, Sentinel-3 OLCI | Selected sites + transect | 2000-2020 |
CRDP-2 | 2 | 1000 m | SPOT4/5-VGT1/2, PROBA-V, Sentinel-3 OLCI, Metop-A/B/C-AVHRR, VIIRS | Selected sites + transect | 2007-2020 |
TDS-2 | 2 | 300 m |
1. Terra/Aqua-MODIS, Envisat-MERIS 2. Terra/Aqua-MODIS, PROBA-V, Sentinel-3 OLCI |
Selected sites + transect |
1. 1 year (e.g. 2010) 2. 1 year (e.g. 2019) |
CRDP-3 | 3 | 1000 m |
Selected sensors from: SPOT4/5-VGT1/2, PROBA-V, Sentinel-3 OLCI, Metop-A/B/C-AVHRR, VIIRS |
Global | 2000-2020 |
CRDP-4 | 3 | 300 m |
Selected sensors from: Terra/Aqua-MODIS, Envisat-MERIS, PROBA-V, Sentinel-3 OLCI |
Global | 2000-2020 |
Team
The Vegetation Parameters CCI+ project is carried out by a consortium of 7 companies/institutes from 6 ESA member states.
Project coordination
- University of Twente (UT), The Netherlands, Christiaan van der Tol is Science Leader
- VITO Remote Sensing, Belgium: Else Swinnen is Project Manager
Algorithm team
Validation team
- EOLAB, Spain, Lead: Fernando Camacho
Engineering team
- VITO Remote Sensing, Belgium, Lead: Michal Moroz
The Climate Research Group (CRG)
- Imperial College London (ICL), UK: Ian Colin Prentice, Catherine Morfoupoulos
- University of Antwerp (UA), Belgium: Manuela Balzarolo
Contacts
Scientific Leader: Christiaan van der Tol
Project Manager: Else Swinnen
ESA Technical Officer: Clement Albergel
News & Events
Latest news & events
2022 CMUG Integration & Climate Change Initiative colocation
ESA's climate research community to meet on 24-27th October 2022
Learn moreOpen call for activities that foster stakeholder engagement on EO research
An open call for Future Earth research networks to collaborate on EO research activities
Learn moreGEO Work Programme 2023-2025 released for consultation
Comments on the Summary document (version 1) welcomed by 1 August
Learn moreVegetation observations focus of new ESA climate project
The aim is to develop long-term global multi-mission time series for LAI and FAPAR
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First user survey to define LAI and FAPAR requirements
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A side event at the UNFCCC Bonn Climate Conference highlights key report
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Bidders meeting planned for 9 June and proposals are invited
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It is climate day on Wednesday 25 May. Here is a run down of the key climate plenary and agora sessions
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