geophysical and morphological processes in the arctic ... in ice-free areas • allows estimation of...

Coastline retrieval • Semi-automatic processor for SAR data • Contrast-based detection of land- water-boundary • Retrieves land-water-line under ice-free conditions • Precision of about 2 image pixels Sea state retrieval • Fully automated processor for Sentinel-1 IW mode and TerraSAR-X data • Retrieves significant wave height H s in ice-free areas • Allows estimation of impacted wave energy to coast during ice- free season Geophysical and morphological processes in the Arctic coastal regions and marginal ice zone by using remote sensing data Stefan Wiehle (1), Andrey Pleskachevsky (1), Anja Frost (1), Mikhail Dobrynin (2) (1) German Aerospace Center (DLR), Remote Sensing Technology Institute, Maritime Safety and Security Lab, Henrich-Focke-Str. 4, 28199 Bremen, Germany (2) University of Hamburg, CEN - Center for Earth System Research and Sustainability, Hamburg, Germany Summary • Climate change severely affects Arctic coasts with erosion rates of up to 2-6 m per year • Remote Sensing with SAR satellites allows estimating coastal erosion in the Arctic • Supporting modelling and observation campaigns with sea state and coastline processor Remote Sensing opportunities • Polar latitude means almost daily coverage by many Earth Observation satellites • Synthetic Aperture Radar (SAR) • Active sensing technology • Penetrates clouds • Independent from illumination, important during polar night • Sentinel-1 mission • 10 m pixel spacing • 250 km swath width • Frequent, regular acquisitions • Free data access • TerraSAR-X mission • Resolutions down to <1 m • Monitoring of areas of interest New Siberian Islands Map of Laptev Sea and New Siberian Islands Delineated coastlines from Sentinel-1 (2015, 10 m pixel spacing, 250 km swath width) and TerraSAR-X Spotlight (2018, 1.5 m pixel spacing, 10 km swath width). The TerraSAR-X scene from March shows the presence of ice; the Sentinel-1 scene from October is ice-free. Sea ice does not allow for automatic coastline detection and even makes manual delineation challenging due to lack of contrast at the coast. TerraSAR-X data © DLR 2018 Sentinel-1 2017-09-25 Time series of 6 images of Sentinel-1 in IW mode, acquired every 12 days from July 27 to September 25, 2017 (left to right), where the Laptev Sea was mostly ice-free. More images are available for adjacent regions from different orbits or in the low-resolution EW acquisition mode The Sentinel-1 SAR satellite (Image: ESA) Permafrost soil at the Laptev Sea coast (Photo: Mikhail Grigoriev) Rising temperatures Ice-free days increasing from 80 to >95 per year Melting of permafrost ground at shores More wave energy impacts coast Increasing coastal erosion, currently 2-6 meters per year H s ~1.5m L p ~ 80m H s ~3.5m L p ~250m TerraSAR-X SM 1.25 m pixel spacing Sentinel-1 IW 10 m pixel spacing Differences in sea state imaging between TerraSAR-X StripMap (SM) and Sentinel-1 Interferometric Wide Swath (IW) mode

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Page 1: Geophysical and morphological processes in the Arctic ... in ice-free areas • Allows estimation of impacted wave energy to coast during ice-free season Geophysical and morphological

Coastline retrieval • Semi-automatic processor for

SAR data • Contrast-based detection of land-

water-boundary • Retrieves land-water-line under

ice-free conditions • Precision of about 2 image pixels Sea state retrieval • Fully automated processor for

Sentinel-1 IW mode and TerraSAR-X data

• Retrieves significant wave height Hs in ice-free areas

• Allows estimation of impacted wave energy to coast during ice-free season

Geophysical and morphological processes in the Arctic coastal regions and marginal ice zone by using remote sensing data Stefan Wiehle (1), Andrey Pleskachevsky (1), Anja Frost (1), Mikhail Dobrynin (2)

(1) German Aerospace Center (DLR), Remote Sensing Technology Institute, Maritime Safety and Security Lab, Henrich-Focke-Str. 4, 28199 Bremen, Germany (2) University of Hamburg, CEN - Center for Earth System Research and Sustainability, Hamburg, Germany

Summary • Climate change severely affects

Arctic coasts with erosion rates of up to 2-6 m per year

• Remote Sensing with SAR satellites allows estimating coastal erosion in the Arctic

• Supporting modelling and observation campaigns with sea state and coastline processor Remote Sensing opportunities

• Polar latitude means almost daily coverage by many Earth Observation satellites

• Synthetic Aperture Radar (SAR) • Active sensing technology • Penetrates clouds • Independent from illumination,

important during polar night • Sentinel-1 mission

• 10 m pixel spacing • 250 km swath width • Frequent, regular acquisitions • Free data access

• TerraSAR-X mission • Resolutions down to <1 m • Monitoring of areas of interest

New Siberian Islands

Map of Laptev Sea and New Siberian Islands

Delineated coastlines from Sentinel-1 (2015, 10 m pixel spacing, 250 km swath width) and TerraSAR-X Spotlight (2018, 1.5 m pixel spacing, 10 km swath width). The TerraSAR-X scene from March shows the presence of ice; the Sentinel-1 scene from October is ice-free. Sea ice does not allow for automatic coastline detection and even makes manual delineation challenging due to lack of contrast at the coast. TerraSAR-X data © DLR 2018

Sentinel-1 2017-09-25

Time series of 6 images of Sentinel-1 in IW mode, acquired every 12 days from July 27 to September 25, 2017 (left to right), where the Laptev Sea was mostly ice-free. More images are available for adjacent regions from different orbits or in the low-resolution EW acquisition mode

The Sentinel-1 SAR satellite (Image: ESA)

Permafrost soil at the Laptev Sea coast (Photo: Mikhail Grigoriev)

Rising temperatures

Ice-free days increasing from 80 to >95 per year Melting of

permafrost ground at

shores More wave energy impacts coast

Increasing coastal erosion, currently 2-6 meters per year

Hs~1.5m Lp~ 80m Hs~3.5m Lp~250m

Terr

aSA

R-X

25 m