Investigation of hydrogen sulphide eruptions along the Namibian coastline using different remote sensing systems

2009 ◽  
Vol 1 (3) ◽  
Author(s):  
Thomas Ohde
Keyword(s):  
Remote Sensing ◽  
Hydrogen Sulphide ◽  
Coastal Upwelling ◽  
Temporal Distribution ◽  
Dust Deposition ◽  
Ocean Colour ◽  
The North ◽  
Microwave Scatterometer ◽  
Westerly Direction ◽  
Remote Sensing Techniques

AbstractHydrogen sulphide eruptions with their typical turquoise discolorations at the water surface are a unique phenomenon along the Namibian coastline. The remote sensing techniques of ocean colour sensors and microwave scatterometers were used for the investigation of such events. The studies with ocean colour sensors showed that the turquoise discolorations near the Namibian coast were neither linked to dust deposition into the water column by desert storms nor to the reflection of bright material in shallow water areas. In addition, other coloured marine events like algae blooms and river outflows were differentiable from the hydrogen sulphide eruptions by their special optical properties. Quasi-true colour images and spectral identification methods were utilised to monitor and investigate the spatial and temporal distribution of sulphide events. In the past years, they were sometimes and locally limited discovered. Newest remote sensing observations including our own investigations have established that the occurrence of sulphide events is more frequent and longer lasting. The north-westerly direction of propagation and their velocity between 12 cm s-1 and 15 cm s1 were derived from an event on 14 April 2004. Lastly, the microwave scatterometer remote sensing was applied to investigate the relation of sulphide events to oceanographic conditions. The events from May 2004 were clearly related to strong coastal upwelling.

Modelling desertification risk in the north-west of Jordan using geospatial and remote sensing techniques

2014 ◽  
Vol 7 (2) ◽  
pp. 531-549 ◽  
Author(s):  
Jawad T. Al-Bakri ◽  
Laura Brown ◽  
Ze’ev Gedalof ◽  
Aaron Berg ◽  
William Nickling ◽  
...  
Keyword(s):  
Remote Sensing ◽  
North West ◽  
The North ◽  
Remote Sensing Techniques ◽  
Desertification Risk

Remote sensing of primary production in the ocean: promise and fulfilment

1995 ◽  
Vol 348 (1324) ◽  
pp. 191-202 ◽  
Keyword(s):  
Remote Sensing ◽  
Primary Production ◽  
North Atlantic ◽  
Local Algorithm ◽  
Ocean Colour ◽  
Remotely Sensed Data ◽  
Local Algorithms ◽  
The North ◽  
Basin Scale ◽  
The North Atlantic

Remote sensing of ocean colour affords us our only window into the synoptic state of the pelagic ecosystem, and is likely to remain the only such option into the foreseeable future. Estimation of primary production from remotely sensed data on ocean colour is a research problem in two parts: (i) the construction of a local algorithm; and (ii) the development of a protocol for extrapolation. Good local algorithms exist but their proper implementation requires that certain parameters be specified. Protocols for extrapolation have to include procedures for the assignment of these parameters. One suitable approach is based on partition of the ocean into a suite of domains and provinces within which physical forcing, and the algal response to it, are distinct. This approach is still in its infancy, but is best developed for the North Atlantic. Using this method, and using the accumulated data from oceanographic expeditions, leads to an estimate for the annual primary production of the North Atlantic at the basin scale. Direct validation of the result is not possible in the absence of an independent calculation, but the potential errors involved may be assessed.

scholarly journals The Roman Military Presence at Dalswinton, Dumfriesshire: a Reassessment of the Evidence from Aerial, Geophysical and LiDAR Survey

Britannia ◽  
2019 ◽  
Vol 50 ◽  
pp. 285-320 ◽  
Author(s):  
W.S. Hanson ◽  
R.E. Jones ◽  
R.H. Jones
Keyword(s):  
Remote Sensing ◽  
Aerial Photography ◽  
Geophysical Survey ◽  
Phase 2 ◽  
North West ◽  
The North ◽  
Military Presence ◽  
Temporary Structure ◽  
Roman Military ◽  
Remote Sensing Techniques

ABSTRACTThe Roman military presence at Dalswinton is reassessed using a range of remote sensing techniques (geophysical survey, LiDAR and aerial photography). At Bankfoot the absence of internal buildings suggests the postulated vexillation fortress was a more temporary structure; while numerous pits/ovens were identified across the interior of the large Stracathro-type camp. The primary fort at Bankhead was provided with in-turned entrances and two small annexes attached to the north-west and south-east quadrants of the fort. A third much larger annexe extended southwards down to the river. Only pits and furnaces were recorded within the annexes, two of which were expanded in Phase 2. Various buildings, including legionary and auxiliary barracks, were identified in the expanded fort of Phase 2, whose orientation remained unchanged. A mixed garrison of legionaries and auxiliary cavalry is indicated for both periods of occupation. Finally, the fort was deliberately demolished. The Roman attribution of the three nearby enclosures at Butterhole Brae can no longer be supported.

scholarly journals KARAKTERISTIK POTENSI ANGIN SEBAGAI SUMBER ENERGI TERBARUKAN DI INDONESIA DARI DATA SATELIT REMOTE SENSING

2019 ◽  
Vol 5 (1) ◽  
pp. 26
Author(s):  
I Ketut Swardika
Keyword(s):  
Remote Sensing ◽  
Renewable Energy ◽  
Turbine Blades ◽  
Electrical Energy ◽  
Energy Potential ◽  
North West ◽  
Technical Parameters ◽  
The North ◽  
Microwave Scatterometer ◽  
Power Curves

Global warming, climate changes mostly associates with solar-renewable energy; however wind-energy potential has no detail reports in Indonesia. This study aims to mapping of characteristics and potential of wind as renewable-energy from long-term (1997-2009) satellite remote-sensing. Wind direction (WD), speed (WS) derives from microwave/ scatterometer sensor on satellite operational years as follows: ADEOS (1997), DMSP (1998-1999), AMI (1997-1999), QuikSCAT (1999- 2009). Data processed into 0.25o grid, monthly temporal resolution. The regional characteristics of WD/WS, seasonal and zonal-longitudinal reveals by statistic. Electrical energy derives from kinetic energy of turbine-blades per-unit time. Energy conversion uses power-curves and technical parameters of 1.50 and 3.40 MW (GE 1.5s, 3.4-137 models) onshore installations with 25km2 per point, 15% availability area. Result shows WS has low characteristics in Indonesian-waters (<3.7ms-1). WS has high at north-south Java-Sumatra, Banda waters (<6.9ms-1). The zonal-seasonal wind variability of WD, WS stables at equator. Increases of degree-zonal (>5deg), wind curve follows north-south hemisphere characteristics and crosses in April, October. The north-west, south-east monsoon shows clearly only on north-western of Java-Sumatra waters. WS has range of 0-25.20ms-1, average 6.64ms-1 with Std. 1.64ms-1. With these WS, generation of electrical energy has range from 104.0 to 2230.5 kWh per-point installation grid.

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