Our society is increasingly weather and climate dependent.
Data from Earth observation and meteorological satellites have become vital for forecasting the weather at all ranges, monitoring the climate, and producing timely warnings and other information that support public and private decision making for our social and economic well-being and sustained development.
Operating Earth observation and meteorological satellites is contributing directly to the implementation of the 2030 Agenda through the provision of global, accurate, consistent and timely observations of the weather, environment and climate from space.
The use of the data from such activities saves lives, prevents economic loss and supports sustainable development and innovation. The fulfilment of these objectives contributes practically and tangibly to the achievement of many of the Sustainable Development Goals.
To be up to the challenge of sustainable development in the next decade and beyond, and to meet expectations from governments, citizens and industries on forecasts and early warnings of high-impact weather events, the availability of a global network of Earth observation and meteorological satellites has to be ensured.
The role of EUMESTAT and other space agencies
Meteorological and Earth observation satellites are equipped with visible and infrared imagers and sounders. The data provided by these instruments are used to derive many meteorological and environmental parameters. The polar-orbiting satellites are additionally equipped with active and passive microwave sensing instruments that provide, for example, vertical profiles of temperature and humidity of the atmosphere, information on the distribution of clouds, snow and ice cover, and ocean surface temperatures and winds, on a global basis.
These atmospheric variables are all known to play an important role in weather forecasting and long-term climate change monitoring.
The primary objective of EUMETSAT, an intergovernmental organization, is to establish, maintain and exploit meteorological satellites, taking into account, as far as possible, the recommendations of the World Meteorological Organization (WMO).
This is done in close cooperation with all other space agencies that operate meteorological satellites, with the shared objective of maintaining a global network of meteorological satellites, in the framework of the Coordination Group of Meteorological Satellites (CGMS). In response to the global climate action agenda, a further objective is to contribute to the operational monitoring of the climate and detection of climatic changes through this global network of Earth-observation and meteorological satellite systems. The implementation of the Global Architecture for Climate Monitoring from Space is coordinated by the Joint Working Groupon Climate established by CGMS and the Committee on Earth Observation Satellites (CEOS).
High-impact weather
Observations from geostationary and non-geostationary meteorological satellites are used by National Meteorological and Hydrological Services (NMHS) across the world in their endeavours to protect life and prevent economic loss from meteorological and hydrological hazards.
Real-time satellite data are either used directly for nowcasting high-impact weather or ingested in numerical prediction models supporting forecasts for ranges from days to seasons.
Additionally, there is a global network of data collection systems on meteorological satellites to collect and relay, in real-time, in-situ observations from automated platforms deployed over continents and oceans. For example, satellites over the Indian Ocean form part of the global tsunami early warning system.
Building on these forecasts, NMHS release early warnings that help reduce the number of people affected by disasters and the related economic loss. Through their use in weather forecasts, weather observations from space also contribute to transport safety and capacity, sustainable development and agriculture, water and land resource management and protection of public health, e.g. in case of heat waves amplified by heat islands in megacities.
Weather forecasts also support economic growth, as our highly-developed economies and many areas of our modern lives are very weather sensitive. This is the case in the transport, energy, agriculture, tourism, food, and construction industries, for example.
Consequently, the socio-economic benefits of forecasts and their constant improvement are proportional to the gross domestic product (GDP) of a country or a region.
Record-breaking Hurricane Dorian during September 2019 making landfall at Elbow Cay, Bahamas, with wind speeds of 295 km/h, observed by a number of instruments on different satellites (Metop‑A, Sentinel‑3B, GOES‑17). The different satellite-based instruments can be used to investigate different characteristics of hurricanes and their impacts as in this example. Image credit: EUMETSAT
Our oceans
One essential component is the monitoring of the oceans.
The resulting integrated marine data stream provides information about ocean currents, ocean surface winds, sea state, sea ice, sea surface temperature and ocean colour.
These data are used directly and ingested in weather and ocean prediction models to provide crucial information for safety at sea, operations of marine infrastructure, fisheries, sustainable use of marine resources and the protection of vital marine and coastal ecosystems.
Mean sea level rise is both an impact and sensitive indicator of climate change with particular repercussions for coastal areas and small island States. Therefore, the availability of reliable, highly accurate mean sea level measurements will be crucial for achieving the central aims of the 2015 Paris Agreement. Those aims are to strengthen the global response to the threat of climate change, as well as countries' ability to deal with its impacts.
Sea level rise observed by 12 satellites over a period of 28 years (top) and a map of regional sea level trends (bottom). Image credit: EUMETSAT
Atmospheric composition
Another important element is the monitoring of the atmospheric composition from space using geostationary and polar-orbiting satellites, in future also with additional dedicated Sentinel instruments provided by the EU Copernicus programme.
These satellite observations provide key inputs to forecasts of air quality over large urban areas, the ozone layer and harmful ultraviolet radiation, as well as sand and dust storms, in particular in Africa.
Public health benefits from the use of this information for regulating traffic or other economic activities and for warning of potential respiratory problems.
The data and imagery are also used for forecasting the dispersion and transport of accidental pollution and to monitor wildfires and the plumes of aerosols and the gases they generate. During the March 2020 lockdown in Europe, although there were different levels of restrictions in different countries, there was a visible decrease
of NO2 emissions. This was more pronounced in the most polluted areas — Po Valley, Ruhr-Rhine, Benelux, London and Paris.
March anomaly of tropospheric column density of NO2 — based on long-term mean (2007–2018). Left: March anomaly of total column of NO2 from Metop‑A and B
GOME‑2. Reference period is 2007–2018. Right: Sentinel 5p TROPOMI NO2 anomaly for March 2020. Reference period is 2019, due to the limited time coverage of the instrument. Images credit: EUMETSAT
Observations of volcanic ash and SO2 plumes are also crucial for ensuring safety of aviation and optimization of air traffic management capacity in case of eruptions.
The ash plume from the eruption of Eyjafjallajökull as seen from Meteosat‑9 on 13 May 2010 revisiting the British Isles and the Benelux countries (left), reaching Belgium, The Netherlands and Germany on18 May 2010 (right). This ash plume seriously impacted civil aviation globally. Image credit: EUMETSAT.
The changing climate
Satellites have unique potential for observing systematically and globally 31 of the 50 Essential Climate Variables (ECVs) identified by the WMO's Global Climate Observing System (GCOS).
With almost 40 years of meteorological satellite data (e.g. from Meteosat satellites), and commitments for collecting another30 years' of observations from its current and next-generation satellites, EUMETSAT, like its international partner space agencies, is one key contributor to the Architecture for Climate Monitoring from Space, jointly coordinated by the Coordination Group for Meteorological Satellites (CGMS) and the Committee on Earth Observation Satellites (CEOS).
Through data rescue, the systematic recalibration of historical data and the reprocessing oblong series of data using the latest algorithms, for example, EUMETSAT alone has already delivered many climate records addressing 15 ECVs. It has further plans to deliver more and improved data records to address additional ECVs from the atmosphere, ocean and terrestrial domains.
Weather forecasts and energy production
The interdependencies between energy, the weather and the climate are increasing.
As the demand for energy remains temperature-dependent, the weather now determines the supply of the renewable part of the energy mix.
Weather forecasts influence day-to-day decisions on energy production, while climate data are essential inputs for well-informed decisions on strategic investments in the energy sector, in particular on preferred energy sources and production capacity.
Observations from meteorological satellites have a twofold contribution as they increase the performance of weather forecasts and are used to produce climate records of solar radiation parameters that can aid decision-making in relation to solar-energy installations.
The need for relevant frequency spectrum resources
The exploitation of these meteorological and Earth-observation satellites relies on the interference-free availability of the necessary frequency resources, which are ensured by the appropriate provisions in the Radio Regulations.
This is important for the control of satellites, the operation of a number of microwave instruments for active and passive sensing, and the timely distribution of the data directly from the satellites, or through alternative means of data distribution using other radiocommunication services. This large portfolio of radio-frequency usage requires that the radio-frequency resources allocated to the corresponding radiocommunication services in the Radio Regulations are kept available and protected from interference in the long term.
This is particularly important for passive microwave sensing instruments, which due to their sensitivity, require particular recognition in the Radio Regulations.
Since weather and climate monitoring are global challenges requiring strategic investments in the necessary global infrastructure, in space and on the ground, for the benefit of human society, the support of radiocommunication administrations from around the world for the protection of these indispensable frequency resources is necessary.
