NASA has produced a couple of articles in the last few weeks demonstrating how Earth Observation (EO) data can help monitor both ends of the temperature spectrum.
Beginning with the heat, theyâ€™ve produced a map of all the fires detected across the UK in the first four months of 2019 using the 375m active fire data product produced from the Visible Infrared Imaging Radiometer Suite (VIIRS), onboard the NOAA/NASA Suomi NPP (National Polar-orbiting Partnership) satellite.
The image at the top of the blog shows the locations of the detected fires, although each dot on the map doesnâ€™t necessarily represent an individual fire. With its 3 040 km swath VIIRS provides full global coverage twice in a day, whilst mid-latitudes locations data can be collected three or four times each day. The product shows days on which an active fire was detected by the fire product algorithm from the data collected which when coupled with the 375 m pixel size may mean that each dot may represent more than one fire. For example, in April it was reported that fire-fighters were tackling twelve separate blazes across seven miles of Dartmoor, near Plymouth, on a single day and so the distribution of these fires would determine the number of fire detections.
Whilst the data suggests that 2019 has already seen more fires at this point than last year, and it is likely that the warmer than normal conditions experienced by the UK earlier this year will have contributed to this increase either through moorland and grasslands drying out quicker than normal, although some fires are reported to have been started by discard barbeques from people taking advantage of the weather. Possibly even the warmer weather itself provided more cloud-free conditions this year enabling more fires to be detected.
Whatever the reason, itâ€™s an important factor to monitor fire detection across the country and EO satellite data provides an effective way of doing so,
The second article is from the opposite end of the thermometer and is all about ice – specifically, a time series of images of the Pine Island Glacier in Antarctica. Pine Island is an outlet glacier – which means itâ€™s a valley glacier which drains an inland ice sheet or ice cap â€“ and is important as itâ€™s generally considered to be the fastest melting glacier in Antarctica accounting for approximately 25% of Antarcticaâ€™s ice loss.
Using the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASAâ€™s Terra satellite images have been taken over a twenty-year period showing changing of the ice-front in the glacier, which can be seen here. Whilst the front itself varies considerably during the time period the researcher’s overall view is that the glacier is retreating. Given the importance of this particular glacier, understanding what is happening and how this feature is changing is vital.
Interestingly, MODIS also has a fire detection product like VIIRS, but its spatial resolution is only 1 km compared to the 375 m of VIIRS.
Two more examples of how EO data can help monitor what is happening in the natural environment.