How Sentinels Can Support Space- Based Weather Predictions

LAND MARINE ATMOSPHERE EMERGENCY MANAGEMENT CLIMATE CHANGE SECURITY

ISSUE 26 / SEPTEMBER 2013

HOW SENTINELS CAN SUPPORT SPACE- Facts BASED WEATHER PREDICTIONS > In Europe, the gross revenue from commercial weather Since many aspects of our lives are dominated by the weather, watching the forecasts amounts to €40 forecast is part of our daily routine. The economic and social benefits of accurate million weather forecasts are immense. For example, they help improve the efficiency of > Overall, weather forecasts agricultural systems, they are used to optimise logistical aspects of transport and in the EU are estimated to energy, and they help ensure our safety. Today's weather forecasts are based on bring financial benefits of €15 to 60 billion/year complex numerical models that assimilate a huge number of different geophysical > More than 90% of all measurements to simulate the behaviour of the atmosphere. The majority of these observational data used in measurements are provided by satellites. Research into ways of improving the global numerical weather forecasts is constantly in progress, particularly with the intent to early warning of prediction comes from extreme events, the nature and frequency of which may change as a consequence satellites of climate change. Copernicus satellites provide global information about the composition of the atmosphere and the state of Earth's surface that can support weather forecasts. Benefits The accuracy and reliability of weather predictions relies on the availability of satellite observations. Sea-state parameters such as sea-surface temperature, waves, currents and sea level can help model the exchange Satellite data support weather processes between the ocean and atmosphere more accurately. Also, atmospheric aerosols, dust and ozone forecasts to concentrations can improve the understanding of the boundary conditions related to atmospheric forcing. > improve day-to-day Different kinds of satellite instruments from radar altimeters and temperature radiometers, to atmospheric reliability by providing ultraviolet spectrometers, can be used to provide additional information complementing data from operational routine observations all over weather missions such as EUMETSAT's Meteosat and MetOp. the globe > improve the accuracy of numerical models and so the The European Centre for Medium-Range understanding of weather Weather Forecasts (ECMWF) is a worldwide processes leading international organisation that develops and operates global models > improve early warning of and data-assimilation systems to predict hazardous weather leading the behaviour of the atmosphere in the to better protection of life medium range and also up to longer and property periods of time by using probabilistic techniques. Every day, its powerful computing systems assimilate in near real-time over 12 millions of observation data from about 60 different satellites and from various ground networks. This Policy Objectives figure is a typical ECMWF chart showing the forecast mean sea level pressure and > EU Water Framework wind speed for 05 November 2012 – these are key parameters in weather forecasts Directive as they show how the air is moving and > EU Flood Directive where storms are developing. > Clean Air for Europe (CAFE) Source: ECMWF

www.esa.int/copernicus • http://copernicus.eu/ ISSUE 26 / SEPTEMBER 2013

COPERNICUSCopernicus servicesACTIVITIES Sentinel contribution Next steps

The Copernicus Services for Atmosphere, The Copernicus Sentinel-3, -4 and -5 and -5P > Establish seamless European monitoring Marine and Land Monitoring make use missions will support weather forecasting by: and forecast services for weather, ocean of satellite data to provide continuous and atmospheric composition at different data and information on atmospheric > determining global sea-surface spatial scales: global, continental, regional, composition and the state of Earth’s temperatures with the Sea and Land local Surface Temperature Radiometer (SLSTR) surface, thereby supporting weather > Improve the skills of numerical models (Sentinel-3) forecasts and reanalysis. using available data from integrated > providing accurate topographic observing systems across all timescales Example products: measurements with an advanced dual- > Continue to acquire high-quality satellite frequency Synthetic Aperture Radar > Nowcasting and forecasting of data for initialisation of predictive models Altimeter (SRAL) (Sentinel-3) atmospheric and ocean parameters at and for ocean–atmosphere and land– global and regional scales > monitoring the composition of the atmosphere coupling atmosphere, including air quality, > Re-analysis of weather parameters at > Provide space-based, consistent real-time stratospheric ozone and solar radiation various temporal resolutions (e.g. dust and re-analysed datasets (Sentinel-4, -5 and -5P) and ozone)

Sentinel-3 ESA's new global environmental satellite

The Sentinel-3 mission main objective is to measure sea- surface topography, sea- and land-surface temperature and ocean- and land-surface colour with high-end accuracy and reliability in support of forecasting systems, as well as for global environmental and climate monitoring. The mission will provide systematic data all over the globe. This is beneficial to support weather forecasts especially for areas where ground networks are scarce - notably over the oceans. Oceans play a key role in governing global weather patterns, and their characterization will become even more important in the future when coupled ocean-atmosphere models are expected to bring further improvements in weather predictions.

The first Sentinel-3 satellite will be ready for launch in 2014, followed by a second satellite to provide the required level of coverage for Copernicus services. The Sentinel-3 marine component will be operated by EUMETSAT, as Sentinel-4 and -5.

This image shows sea-surface temperature over the Atlantic as measured by Envisat's Advanced Along Track Scanning Radiometer (AATSR). The blue areas are corresponding to coldest waters and red to the warmest. AATSR, a precursor of the SLSTR that will be carried on Sentinel-3, was capable of measuring sea-surface temperature to an accuracy of a few tenths of a degree. Source: ESA