Sentinel-1 Sees Through Surigae's Clouds

ESA's radar satellite strips away the storm's canopy to reveal the violent sea surface beneath Typhoon Surigae.

By The space-quantum Desk

Most typhoon imagery gives you white spirals against blue ocean. [1]

At the time of acquisition, Surigae was tracking north-eastwards across the Philippine Sea, roughly 200 km south of Shikoku, Japan. By 1 October it was almost 1000 km away, placing it about 200 km south of Tokyo. [1]

The colour in the image is not decorative. ESA's radar instrument records two separate polarisations, each mapped to a distinct colour channel. [1]

Radar's ability to pierce cloud cover makes it the instrument of record when optical sensors are blind — which, in the middle of a typhoon, is always.

Since the image was taken, Surigae has weakened considerably and is currently classed as a tropical depression, with maximum wind speeds of 55 km per hour — a fraction of its peak intensity. [1]

The image is part of ESA's ongoing Earth from Space collection, processed from modified Copernicus Sentinel data and available under a CC BY-SA 3.0 IGO licence or ESA Standard Licence — content can be used under either. [1]

The orange-yellow ring in the image is where the radar instrument has detected rough ocean conditions and strong winds.ESA