How sensitive are sediment dispersal and sea surface temperature to changing wind conditions? A mapping approach in the coastal waters of Herschel Island, Yukon Territory, Canada, using Landsat (TM, ETM+ and OLI/TIRS) satellite image data from 1986 to 2016.

• Main Author: Klein, Konstantin
• Format: Thesis
• Language: unknown
• Published: 2017
• Subjects: Climate change; Herschel; Herschel Island; Mackenzie river; permafrost; Yukon
• Online Access: https://epic.awi.de/id/eprint/48186/; https://epic.awi.de/id/eprint/48186/1/Thesis_combined_refs_2018_10_09.pdf; https://hdl.handle.net/10013/epic.4b993b6d-fc1e-4b47-9d3a-23f12eec5207

The Arctic is subject to substantial changes due to the greenhouse gas induced climate change. Ground temperatures and river discharge are rising, (permafrost) coasts are eroded and the carbon stored in them is released. The aforementioned factors contribute suspended sediment to the Arctic shelves which represent an uncertainty regarding future ecological and geological reactions. In order to increase the understanding of the development of Arctic shelves due to the changes described, this Master’s thesis presents a mapping approach of sediment dispersal and sea surface temperature (SST) in the coastal and nearshore zone of Herschel Island on the Canadian Beaufort Shelf. In this regard, 30 years of Landsat satellite imagery were analyzed and interpreted under different seasonal wind conditions (E and NW wind). Due to the absence of in-situ measurements to calibrate the spectral data, proxys were chosen for both values to receive a relative overview of the study area: the surface reflectance of the red band (655 nm) for turbidity (which acts as proxy for sediment dispersal) and at-sensor (uncorrected) temperature from thermal infrared channels (10,4–12,5 µm) for SST. For scenes with similar wind conditions, the mean was calculated, resulting in a very good representation over the observation period. During stable E wind conditions, the mean values of both turbidity and SST were higher than during NW wind conditions. This may result from the influence of the Mackenzie River Plume, distributing suspended sediment and fresh water over the Canadian Beaufort Shelf during stable E wind conditions. The low values during stable NW wind conditions indicate that the sediment and fresh water input from other sources than the Mackenzie River to the Canadian Beaufort Shelf are of minor importance compared to it. Turbidity shows large gradients from the nearshore to the offshore zone, indicating that large parts of the suspended sediment are deposited and transported in the nearshore zone. SST does not have such a strong ...