Observations from space provide valuable information that contributes a great deal towards our understanding and effective management of climate change. MeteoSwiss is participating in the Climate Change Initiative of the European Space Agency (ESA) to maximise the potential for long-term observations of the earth.
| Project start | 01.01.2014 |
|---|---|
| Project end | 31.12.2016 |
| Region | International |
| Status | Completed projects |
Climate change is probably the biggest challenge for humanity in the 21st century, and it is becoming increasingly obvious that observations from space are critical in this regard. However, there is not as yet a coordinated, long-term programme to make these data globally available, as is already the case in meteorology, for example. Moreover, climate monitoring requires data to be stored over long periods of time, in order to provide reliable long-term records. Over the past few years, continuous and formalised dialogue between the authorities responsible for climate monitoring specification and space agencies has produced a coherent set of requirements on which there is worldwide agreement.
The European Space Agency has initiated a new programme with the aim of creating a lasting collection of climate observations: the Global Monitoring of Essential Climate Variables (ECV). The aim of the programme is to maximise the potential of the global archive of long-term observations of the earth that have been collected by the ESA over the past 30 years. The ESA Climate Change Initiative (ESA CCI) fulfils the extremely stringent set of requirements for highly stable, satellite-based long-term climate products, as laid down for the space agencies by the Global Climate Observing System (GCOS) and the Committee on Earth Observation Satellites (CEOS). The ESA CCI provides an important contribution to the ECV databases required by the United Nations Framework Convention on Climate Change (UNFCCC).
The initiative will set in motion a programme of work that will enable all ESA member states to contribute to solving the problems associated with climate change. The programme is based on the provision of climate variables derived from all available satellite datasets, and encompasses all aspects of data availability, including data acquisition, calibration and validation, long-term algorithm maintenance, data curation and reprocessing as required - all within the context of a set of internationally agreed priorities.
The ESA programme will bring together European expertise covering the full range of scientific, technical and development specialisations in the field of earth observation. Moreover, it will provide climate researchers and working groups around the world with lasting and transparent access to the data and findings.
The objective of the ESA CCI Clouds project is to provide long-term coherent cloud property datasets, exploiting the opportunities for synergy of various earth observation missions. This provides a greater degree of accuracy with enhanced temporal and spatial sampling than can be obtained from cloud property datasets that stem from a single source.
The ESA CCI Clouds project is designed to maximise the growing synergistic potential of past, current and future European and US satellite missions in order to meet the increasing demands for coherent long-term cloud property datasets within the scientific community. The primary objectives of the ESA CCI Cloud project are:
Climate monitoring applications: Characterisation stability and homogeneity of the CCI Cloud dataset: The potential of homogeneous long-term observations of cloud cover by satellites to complement long-term ground-based observations will only be significant when they are able to be estimated with a stability of around 1% or better over several decades. In spite of advances in retrieval algorithms, satellite-based cloud cover climatology is hampered by issues with technical artefacts, such as changes in satellite sensors, radiometric and geometric calibration problems, unwanted effects of optical angles or shifts in the diurnal overpass time. For this reason, MeteoSwiss has introduced the following research tasks into the ESA CCI Clouds project:
Integration of Cloud CCI into a flagship project for national GFCS activities: MeteoSwiss plays an active role in preparing the Cloud CCI data, and communicating it and making it available to the interested user community. The climate information user group recently expanded from a 'purely' scientific community of climate specialists into one which encompasses a wide range of users, such as social scientists, decision-makers, resource managers, health officials, reinsurance officials etc. This means that climate data providers share the responsibility not only for generating optimum quality data, but also for preparing the climate monitoring information in ways that make it useful for a wide range of users In the context of this remit, it is proposed that the final, validated Cloud CCI data retrieved over a 30+ year period be used in a national climate monitoring showcase project for Switzerland.
As part of this remit, MeteoSwiss provided validation activities with a particular focus on mountainous and polar regions: Such areas are most sensitive to climate fluctuations and change, and therefore require high quality data recording for the purposes of climate analysis. Furthermore, it is important from a scientific perspective that such an evaluation is conducted independently of the dataset producers.
The role of MeteoSwiss was to evaluate the ESA CCI cloud cover data derived from the AVHRR and MODIS sensors in comparison with the in-situ data for the relevant weather conditions in mountainous and polar regions (Antarctica, Spitzbergen and Greenland). In addition to reporting on the overall accuracy of the CCI cloud cover for these regions, this study also focused on finding the major inaccuracies between the satellite-based cloud cover and surface-based observations, in order to identify the main limitations of the satellite-based cloud cover retrieval algorithm. The identification of these limitations proved to be beneficial to the algorithm developers in the second phase of the CCI Clouds project, helping them to improve the cloud recognition methods.
The Ozone CCI project is part of the ESA Global Monitoring of Essential Climate Variables (ECVs) programme, more commonly known as the Climate Change Initiative (CCI), the second phase of which was begun in 2010 for a period of six years.
The CCI programme is intended to make a contribution to the databases that collect ECVs as required by the United Nations Framework Convention on climate change (UNFCCC) and the International Panel on Climate Change (IPCC).
Specifically, the ESA CCI Ozone project involves the following tasks:
Three main product lines are being developed:
The following diagram explains the concept:
Before the data is produced, the following questions have to be answered:
The scientists at MeteoSwiss have therefore produced a document containing the users' requirements.