2017 seen from the sky – A personal selection

2017 is about finishing, 2018 is going to take over. Here is a personal retrospective view on 2017 with a subjective selection of remarkable satellite images.

Massive wildfires spread across parts of the world such as Chile; Western Canada and the United States; Portugal and Spain; France and even Greenland in 2017. The most recent once, California’s Thomas Fire, was even the largest wildfire of the year in the state. MODIS AquaAqua, Sentinel-2 and many other space-borne instruments reveal these episodes and their intensity. Due to the on-going changes in our climate, it is unfortunately expected that such fires will occur again in 2018, perhaps even stronger.

Smoke from the Greenland fire, August 2017, seen in satellite images copernicus sentinel -2b/pierre Markuse/ESA (Source: https://www.newscientist.com/article/2143159-largest-ever-wildfire-in-greenland-seen-burning-from-space)

Natural-color images from MODIS-Aqua sensor, over east Canada within the period of 2017.07.31-2017.08.08. Red points indicate actively burning areas identified from MODIS, on-board Terra and Aqua platforms. Smokes stretch very far away from these points (Source: https://worldview.earthdata.nasa.gov).

Red Sun, dust and smoke in Europe

In October 2017, a unique combination of 2 independent events – fires in Portugal & Spain, and a tropical storm – brought dust and smoke all over Europe leading then an unusual red Sun observed in France, UK, Finland and the Netherlands. These events were observed notably by OMI, GOME-2 and MODIS Aqua. More information in No borders for particles! – Red Sun, Saharan dust and smoke over whole Europe

MODIS-Aqua visible image on 17.10.2017 (right) acquired in early afternoon: dust particles in yellow over France, united Kingdom and the Netherlands (Source: https://worldview.earthdata.nasa.gov)

Aerosol Absorbing Index (AAI) from GOME-2 sensor on-board MetOp-B platform on 16-17-18.10.2017. Copyright KNMI, EUMETSAT and the Atmospheric Composition (AC) Satellite Applicattion facilities (SAF) (Source: http://www.temis.nl/o3msaf/vaac/vaac_gome2.php?sat=gome2b&year=2017&datatype=pics&freq=daily&filter=Filtered&region=Europe).

A huge 100-Mile Iceberg breaking away from Antarctica

An iceberg of 120 miles long and with a weight of more than a trillion metric tons broke away in Antarctica last July. It was floating along the so-called Larsen-C ice shell and was carefully monitored by worldwide scientists, notably by Sentinel-1 images. This event rose even more concerns about how Antarctica is evolving in the context of a warmer climate and sea level perturbations.

Such event was well documented in near-real time by our colleague Stef Lhermitte from GRS-TU Delft.

California wildfire lights in, Puerto Rico lights out

Satellite images of Earth “night lights” have been a curiosity for the public and a tool of fundamental research for at least 25 years. New global maps have been released by NASA’s Goddard Space Flight Center using the NASA-NOAA Suomi National Polar-orbiting Partnership (Suomi-NPP) satellite. Some of them depict in an impressive way some dramatic episodes of this year: Hurricane Maria struck Puerto Rico, a commonwealth of the United States, leaving the island devastated and all but destroying its power grid; the fast-moving fire that swept into Ventura, California, on December 5, 2017. looking as bright as the urban Los Angeles area.

SUOMI-NPP images o night light in Puerto Rico on September 27-28 2017. One image in each pair shows a typical night before Maria made landfall, based upon cloud-free and low moonlight conditions; the second image is a composite that shows light detected by VIIRS on the nights of September 27 and 28, 2017. By compositing two nights, the image has fewer clouds blocking the view. (Note: some clouds still blocked light emissions during the two nights, especially across southeastern and western Puerto Rico.) The images above show widespread outages around San Juan, including key hospital and transportation infrastructure. Credit NASA (Source: https://earthobservatory.nasa.gov/IOTD/view.php?id=91044).

The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this nighttime image of the fire at 1:05 a.m. local time (09:05 Universal Time) on December 5, 2017. Credit NASA (Source: https://earthobservatory.nasa.gov/NaturalHazards/view.php?id=91376).

Monitoring hurricanes

Given the important images, it is important to monitor the mentioned hurricanes and tropical storms. Satellites like Sentinel-3 allow not only to characterise them (e.g. in terms of brightness temperature) but also to follow their displacement.

First air quality images from TROPOMI aboard Sentinel-5 Precursor (P)

Of course, how not to finish this series without mentioning Sentinel-5 P and its instrument TROPOMI? Many persons waited for it for more than 10 years. I personally heard about it the first time some 5-6 years ago, and then waited for its launch during the last 4 years while working on my research with its predecessor OMI. And finally, just a few months before the end of my current job, Sentinel-5 P was launched, a very happy Friday 13th (October)!

With its unique high spatial resolution (7 x 3.5 km2) and top design sensor, this is the very first European operational mission dedicated to atmospheric composition within the Copernicus programme. The instrument is still under calibration until April 2018, being prepared for the developed services, and many works have to be done to derive accurate estimations of toxic gases and particles in the atmosphere. But the very 1st revealed maps of NO2 – Nitrogen dioxide, SO2 – Sulphur dioxide, O3 – Ozone, CO – Carbon monoxide are already outstanding. What is mostly remarkable are the very fine scale structures of all the pollution plumes already visible.

No doubt that the next months and years will be promising for this instrument. Air pollutants will be seen in much more detail than what has been accomplished before. And, while these first results demonstrate the sophistication of the satellite’s instrument, they certainly bring the issue of air pollution sharply into focus. Even though I am going to work on another project in 2018, I will keep a close eye on the next results from TROPOMI S5P.

One of the first images from the Copernicus Sentinel-5P mission shows nitrogen dioxide over Europe on 22 November 2017. It shows high emissions over the Po Valley in northern Italy and over western Germany. Nitrogen dioxide pollutes the air mainly as a result of industrial fossil fuel combustion and road traffic. Credit KNMI/ESA (Source: http://www.esa.int/spaceinimages/Images/2017/12/Sentinel-5P_sees_nitrogen_dioxide_over_Europe).

SO2 – Sulphur dioxide observed by TROPOMI from the Mount Agung volcanic eruption on Bali, Indonesia, on 27 November 2017. Credit KNMI/ESA (Source: http://www.esa.int/spaceinimages/Images/2017/12/Sentinel-5P_captures_Bali_volcanic_eruption).

Smoke plume from TROPOMI S5P in California region. Credit KNMI / ESA (Source: http://www.bbc.com/news/science-environment-42375062).

CO – Carbon monoxide from TROPOMI S5P. Credit SRON/KNMI.

And in addition look at this NO2 global animation – an average over a couple of days from TROPOMI S5P. Credit KNMI / ESA here.

And so many other pictures of 2017 that I could have posted here, but I invite you to have a look to my past posted weblog pages.

Looking forward to more images and discoveries from space in 2018! And I wish to everyone reading this a Merry Christmas and a very healthy & happy new year!