What has Metop-A seen in 15 years?

Volcanic eruptions

Early data showing Mount Etna

The first EUMETSAT case that included Metop-A data was about the Sicilian volcano Mount Etna — one of the world's most active volcanoes. In November 2006, just a month after Metop-A was launched and before it was declared fully operational, the AVHRR instrument captured imagery of the eruption (Figure 1). The smoke plume can be seen top right in the image.

See the case Monitoring Mount Etna for more than 20 years

Disruptive Icelandic volcanoes

In Spring 2010 and 2011 aviation traffic was shutdown due to the eruptions of Eyjafjallajökull and Grímsvötn in Iceland.

This colourful enhanced Metop-A AVHRR image (Figure 2) shows the extent of the Eyjafjallajökull plume in May 2010.

See the case Eyjafjallajökull volcanic eruption

Following the eruption of the Grímsvötn volcano on the evening of 21 May 2011, two separate plumes of ejected sulphur dioxide (SO₂). The high-resolution Metop-A IASI instrument observed the SO₂ as it spread out over Greenland, Canada, the polar regions and towards Siberia.

See the case Grimsvötn volcanic ash and SO2 plumes

Tracking sulphur dioxide from the Raikoke volcano

In more recent years Metop-A data was more extensively used for analysis of the plume, rather than just images of volcanic plumes themselves, as this case from 2019 shows.

The GOME-2 instruments on Metop-A and B detected the evolution of sulphur dioxide plumes from the Raikoke volcano in the Kuril Islands in June 2019. The AC SAF SO₂ products (Figures 4 and 5) show the very small expulsion of SO₂ on 21 June and the swirling mass of SO₂ by 27 June.

See the case Eruption of the Raikoke volcano

Air quality

Monitoring the ozone hole

Metop GOME-2 data was used by scientists at the Deutsche Zentrum für Luft- und Raumfahrt (DLR), the German Aerospace Center, for the long-term monitoring of the evolution of the ozone hole.

In 2007, the DLR noted a strong reversal in the spreading of the ozone hole in mid-September because of an unusual meteorological circulation in the south polar stratosphere. An unusually high intensity of planetary waves — which cause air circulation around the world — resulted in the thinning of the ozone layer, especially over the south Atlantic and South America. At the same time, the ozone level rose over Australia.

The 2007 ozone hole over the Antarctic was at its maximum size, twice as big as Europe, at the end of September.

See the case Metop-A measures ozone hole over the Antarctic

Less pollution during COVID lockdown

More recently, in 2020, analysis of total column of NO₂ from Metop-A (and -B) GOME-2 helped to show that the COVID-19 lockdown earlier in the year had a visible effect on pollution.

Figure 7 shows the decrease in NO₂ in March 2020, seen by GOME-2 instruments. The difference was calculated based on the average March concentrations from 2007–2018.

During the March lockdown, although there were different levels of restrictions in different countries in Europe, there was a visible decrease, more pronounced in the most polluted areas — Po Valley, Ruhr-Rhine, Benelux, London and Paris. The decrease peaked to 6x10^15 mol/cm² with an average decrease of approximately 30% to 50%, compared to previous years.

See the case Pollution levels drop during COVID-19 lockdown

Ice

Greenland ice sheet melting

Between 10 and 12 July 2012, backscatter data from the ASCAT instrument on Metop-A detected a very fast surface snow melt event, covering almost the entire Greenland ice sheet.

Figure 8 shows the false colour RGB images from Metop-A ASCAT and Oceansat-2 OSCAT, 8 and 11 July 2012. This image is from a single day of C-band data (ASCAT) and Ku-band data (Oceansat-2). Land is grey, summer melt is the dark green, fast surface melt is red, refrozen melt is bright white, unmelted firn is dark grey/blue.

See the case Extreme Greenland ice sheet melt

Climate experts are using Metop data records to observe the cooling of the North Atlantic Ocean during the last decade due to the melting of Greenland ice sheet. The Ocean and Sea Ice Satellite Application Facility (OSI SAF) provides data records of Sea Surface Temperatures (SST) derived from cloud cleared Advanced Very High Resolution Radiometer (AVHRR) observations from the Metop and NOAA satellites.

See the case Melting Greenland ice sheet cools North Atlantic Ocean

Snow

Snowfall is usually very rare in the Canary Islands, but in February 2016 unusual heavy snow hit and Metop-A was ideally placed to see the lying snow a few days later. The Metop-A AVHRR Natural Colour RGB image from 21 February at 11:13 UTC (Figure 10) gave a good view of the snow in Tenerife's highlands.

See the case Unusual heavy snowfalls in the Canary Islands

Fires

Catastrophic fires in California

The October 2007 California wildfires were a series of wildfires that burned across Southern California from 20 to 24 October. At least 1,500 homes were destroyed and approximately 972,147 acres of land was burned from Santa Barbara County to Mexico border.

The Metop-A AVHRR image from 22 October (Figure 11) showed masses of smoke pouring off the coastline.

See the case Catastrophic fires in California

Notre-Dame fire

In April 2019 fire destroyed part of the historic Parisian cathedral Notre-Dame. Hotspots from those devastating fires were captured in Metop-A imagery.

On 15 April at 20:09 UTC Metop-A passed over the fire while it was still ongoing and observed the region around Paris at near-nadir viewing angle. The 1km full resolution area coverage data (Figure 12) showed a 3.7µm brightness temperature which was roughly 291.1K (18.0ºC).

See the case Devastating fire at Notre-Dame

Tropical cyclones

Hurricane Sandy

Hurricane Sandy was one of the most significant storms in northeast US history. The storm resulted in 185 fatalities (at least 65 of those in the Caribbean) and caused over $50 billion in damage, making it the second most costly hurricane in US history, behind Hurricane Katrina in 2005.

Figure 13 is the Metop-A AVHRR image of Sandy when it had intensified into a strong category 1 hurricane, with winds of 90mph and the wind field measured over 1,000 nautical miles in diameter, and was approaching the US east coast on 29 October 2012.

See the case Hurricane Sandy hits the USA

Tropical Cyclone Ashobaa

In early June 2015, Tropical Cyclone Ashobaa formed over the Indian Ocean, and then headed towards Oman. According to the Oman Department of Meteorology, the island of Masirah (off the east coast of Oman) received 239.4mm of rain during the three days that Ashobaa affected the country.

It can be seen from Figure 14 that the centre of the cyclone was not visible in Metop-A infrared (AVHRR) imagery but clearly appeared in microwave (MHS) imagery.

MHS and AVHRR comparison

Metop-A IR 10.8, 9 June 05:29 UTC Metop-A MHS 89 GHz, 9 June 05:29 UTC

 

See the case Tropical Cyclone Ashobaa

Busy in the Indian Ocean

2019 saw a lot of cyclonic activity in the northern Indian Ocean, with five systems being generated. Two of the cyclones (Fani and Vayu) were pre-monsoon and three (Hikka, Kyarr and Maha) were post-monsoon. Kyarr was strongest tropical cyclone ever recorded in the Arabian Sea.

The IR10.8 image from Meteosat-8 (Figure 15) detected the centre of the cyclone at the same time as Metop-A passed overhead, thus the ASCAT wind product showed the same position as the Meteosat-8 image. The ASCAT product in this image also gives an indication of the high wind speeds when this was a category 4 cyclone.

See the case Active Indian Ocean tropical cyclone season

Flooding

Parts of the Middle East were left devastated after severe floods in late March and early April 2019. The morning view from Metop-A on 8 April (Figure 16) shows the state of flooding in the border region between Iraq and Iran, though isolated flooded areas could be found on many different places in the region.

See the case Widespread flooding in the Middle East

Ship trails

Contrails are a common sight in our skies but did you know we can also see ship trails in satellites imagery?

In March 2007, Metop-A captured impressive views of ship trails off North America (Figure 17).

See the case Ship trails & industrial plumes