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2015
2015
2015
Monitoring aerosol optical depth during the Arctic night: Instrument development and first results
Moon-photometric measurements were made at two locations in the Arctic during winter nights using two different modified Sun photometers; a Carter Scott SP02 and a Precision Filter Radiometer (PFR) developed at PMOD/WRC. Values of aerosol optical depth (AOD) were derived from spectral irradiance measurements made at four wavelengths for each of the devices. The SP02 was located near Barrow, Alaska and recorded data from November 2012 to March 2013, spanning five lunar cycles, while the PFR was deployed to Ny-Ålesund, Svalbard each winter from February 2014 to February 2019 for a total of 56 measurement periods. A methodology was developed to process the raw data, involving calibration of the instruments and normalizing measured spectral irradiance values in accordance with site-specific determinations of the extraterrestrial atmospheric irradiance (ETI) as Moon phase cycled. Uncertainties of the derived AOD values were also evaluated and found to be in the range, 0.006–0.030, depending on wavelength and which device was evaluated.
The magnitudes of AOD determined for the two sites were in general agreement with those reported in the literature for sunlit periods just before and after the dark periods of Arctic night. Those for the PFR were also compared with data obtained using star photometers and a Cimel CE318-T, recently deployed to Ny-Ålesund, showing that Moon photometry is viable as a means to monitor AOD during the Arctic night. Such data are valuable for more complete assessments of the role aerosols play in modulating climate, the validation of AOD derived using various remote sensing techniques, and applications related to climate modeling.
Elsevier
2024
2012
2012
2013
2012
2012
2011
1999
2011
Monitoring atmospheric composition and deposition in Norway
The Norwegian monitoring programme is set up to meet national and international obligations and needs for measurement data with a long-term commitment. The data are important for compliance monitoring as well as input for effect studies. The monitoring of atmospheric composition and deposition are organised under national programmes mainly funded by the Norwegian Environment Agency in addition to some direct support from the Ministry of Climate and Environment. NILU – Norwegian Institute for Air Research is responsible for the daily operation and reporting of the results from this monitoring. The monitoring aim to fulfil several inter-connected purposes and is divided in four main programmes: transboundary fluxes, contaminants, climate change and the ozone layer. In addition, regularly moss surveys are conducted to assess atmospheric deposition of pollutants such as heavy metals.
NILU
2022
2004
2013