Imaging service

Supporting nowcasting applications

Nowcasting applications are the focus of the imaging services.

Last Updated

14 December 2022

Published on

21 May 2020

This can be done through the visual identification and characterisation of weather systems, their quantitative assessment via more advanced quantitative products, or very short-range prediction using extrapolated or probabilistic products that rely on data from MTG imagers.

Spectral imaging

Applications benefiting from the spectral imagery mission, achieved through the Flexible Combined Imager (FCI) instrument:

Improved meteorological information about the rapid processes of the atmospheric water cycle, resulting in improved severe weather forecasts and early warnings.
Daytime total column precipitable water retrieval enhanced with support of 0.91µm channel, especially over land.
Improved detection of very thin cirrus clouds assisted with 1.375µm channel.
Improved retrieval of cloud microphysics with additional 2.26µm 'microphysical’ channel.
True colour imagery available for first time, supported by new 0.44µm and 0.51µm channels.
Improved aerosol retrievals, especially over land — important for volcanic ash and air quality monitoring.
Improved fire detection via extended dynamical range of the 3.8µm channel.
Increase in the quality of climate relevant products, through higher spatial resolution.

Figures 1–8 are comparisons between current imagery from SEVIRI on MSG, the MODIS instruments on board NASA's Terra and Aqua satellites and the VIIRS instrument on Suomi-NPP. Imagery from MTG will have comparable resolution to that from the MODIS instruments.

MTG example SEVIRI v MODIS Ash — Figure 1: Example of ash detection, SEVIRI Natural Colour RGB, 12:15 UTC, 26 November 2006 (left), MODIS True Colour RGB, 12:20 UTC, 26 November 2006

MTG example SEVIRI v MODIS Dust — Figure 2: Example of dust monitoring, SEVIRI Dust RGB, 18:00 UTC, 29 October 2010 (left), MODIS Dust RGB, 18:15 UTC, 29 October 2010

MTG example SEVIRI v MODIS Thin Clouds — Figure 3: Example of thin cloud detection, SEVIRI Dust RGB, 11:00 UTC, 23 May 2005 (left), MODIS NIR1.3, 11:00 UTC, 23 May 2005

MTG example SEVIRI v MODIS Sev Con — Figure 4: Example of severe convection detection/cloud microphysics, SEVIRI RGB Composite (VIS0.6, NIR1.6, IR10.8), 11:45 UTC, 27 November 2009 (left), MODIS RGB Composite (VIS0.6, NIR2.2, IR11.0), 11:47 UTC, 27 November 2009

MTG example SEVIRI v VIIRS Convective Clouds — Figure 5: Example of convective cloud detection, 11 June 2018, 11:37 UTC; SEVIRI data (left), and FCI imagery (right) simulated over Central Europe based on data from the VIIRS instrument on the NOAA Suomi-NPP satellite; combining 0.865µm imagery (background) and 11.45µm (convective storms) to a ‘sandwich’ product.

MTG example SEVIRI v VIIRS Fog — Figure 6: Example of fog detection, 16 Nov 2018, 01.37 UTC; simulated FCI imagery at 2km spatial resolution based on data from the VIIRS instrument on the NOAA Suomi-NPP satellite (right panel), and SEVIRI imagery at approximately 5km spatial resolution over Czech Republic (3km spatial resolution at sub-satellite point, left panel; Brightness Temperature differences (VIIRS I4 (3.7µm)–I5 (10.8 µm); SEVIRI 3.9µm–10.8µm)

MTG example SEVIRI v MODIS Fire — Figure 7: Example of fire detection: MSG SEVIRI 3.9µm channel at 3km sampling distance, with brightness temperature saturating at 344K (red pixels) (left), MODIS 3.9µm channel at 1km sampling distance (right) simulating FCI imagery, showing more detailed fire locations and a range of fire brightness temperatures (yellow-orange-red colours); Botswana, 29 August 2008.

MTG example SEVIRI v MODIS Fire (Portugal) — Figure 8: Example of fire detection: MSG SEVIRI RGB 3km spatial sampling distance (left), MODIS RGB imagery as proxy for FCI at 1km spatial sampling distance (right). Portugal, 5 August 2018.

Figure 9: Comparison of full-disc and rapid scanning between current SEVIRI (left) and future FCI (right)

Lightning imaging

Applications benefiting from the lightning imagery mission, achieved through the Lightning Imager (LI) instrument:

Improvements for nowcasting and very short range forecasting of severe thunderstorms through information on total lightning (intra-cloud, cloud-to-ground, and cloud-to-cloud lightning). Note: with optical pulse detection, it is not possible to distinguish between cloud-to-ground and cloud-to-cloud lightning.
Continuous and simultaneous observations of total lightning in geostationary field of view, with high timeliness (120s, with goal of reaching 60s).
Detection, monitoring, tracking and extrapolate of the development of active convective areas and storm life cycles.
By providing data on the total lightning, the LI instrument will help improve the quality of information essential for air traffic routing and safety.

MTG Lightning Imager (LI): U.S. Proxy Data — Figure 10: Comparison of full-disc and rapid scanning between current SEVIRI (left) and future FCI (right) using GOES ABI imagery as proxy.

Figure 11: Simulated lightning event for 24 hours on 16 June 2013

Service details

The information delivered to the users will be the time, position and intensity of detected optical pulses converted into geophysical flashes (point data).

Additionally, users will be provided with accumulated flashes over a period of 30 seconds (gridded data on the same grid as FCI instrument data, derived from accumulated point data), which can be further stacked for longer integration periods depending on the users’ application.

Continuous and simultaneous observations of total lightning with almost full-disc coverage, delivered to the users with very high timeliness provides (together with the associated FCI data) a valuable tool for assessment and nowcasting of severe weather from pure satellite data, over almost the full satellite field of view. An example of such an integrated view is provided from the GOES-16 pre-operational data (Figure 12).

MTG Services GOES16 Proxy example — Figure 12: GOES-16 pre-operational data. Credit: NOAA/NASA

LI and climate

For climate purposes the LI will:

Help in assessing the impact of climate change on thunderstorm activity.
Aid the study and monitoring of the physical and chemical processes in the atmosphere regarding nitrogen oxide (NOx), which plays a key role in the ozone conversion process and acid rain generation.
Provide information on a global scale with known error-characteristics. This information is needed in regional models to improve very short-range forecasts of convective events and verification/validation of algorithms to nowcast convective initiation (time and location).

An example of statistics derived from similar climate dataset from LIS and OTD instruments is shown in Figure 13.

MTG Services climate dataset from LIS and OTD instruments — Figure 13: Climate dataset from LIS and OTD instruments. Credit: NOAA/NASA

Further services

Geostationary Search and Rescue (GEOSAR) Relay

MTG carries a small communications payload (GEOSAR) to relay distress signals of 406MHz beacons to a central reception station in Europe, which passes the signals on for quick organisation of rescue activities. The geostationary relay allows a continuous monitoring of the earth disc and immediate alerting.

Data collection and retransmission

MTG will provide a data collection and retransmission service to collect and relay environmental data from automated data collection platforms, including surface, buoy, ship, balloon or airborne platform.