Browsing Bergen Open Research Archive by Author "Ólafsson, Haraldur"

Now showing items 1-9 of 9

    • Airborne observations of the Eyjafjalla volcano ash cloud over Europe during air space closure in April and May 2010 

      Schumann, U.; Weinzierl, B; Reitebuch, O; Schlager, H.; Minikin, A; Forster, C; Baumann, R; Sailer, T; Graf, K; Mannstein, H.; Voigt, C; Rahm, S; Simmet, R; Scheibe, M; Lichtenstern, M; Stock, P; Ruba, H; Schauble, D; Tafferner, A; Rautenhaus, M; Gerz, T; Ziereis, H; Krautstrunk, M; Mallaun, C; Gayet, JF; Lieke, K; Kandler, K; Ebert, M; Weinbruch, S; Stohl, Andreas; Gasteiger, J; Gross, S; Freudenthaler, V; Wiegner, M; Ansmann, A; Tesche, M; Ólafsson, Haraldur; Sturm, K (Peer reviewed; Journal article, 2011-03-11)
      Airborne lidar and in-situ measurements of aerosols and trace gases were performed in volcanic ash plumes over Europe between Southern Germany and Iceland with the Falcon aircraft during the eruption period of the Eyjafjalla ...

    • Aircraft-based observations and high-resolution simulations of an Icelandic dust storm 

      Blechschmidt, Anne-Marlene; Kristjansson, Jon Egill; Ólafsson, Haraldur; Burkhart, John; Hodnebrog, Øivind; Rosenberg, P.D. (Peer reviewed; Journal article, 2012-11-16)
      The first aircraft-based observations of an Icelandic dust storm are presented. The measurements were carried out over the ocean near Iceland's south coast in February 2007. This dust event occurred in conjunction with an ...

    • Downslope windstorm in Iceland –WRF/MM5 model comparison 

      Rögnvaldsson, Ólafur; Bao, J. W.; Ágústsson, Hálfdán; Ólafsson, Haraldur (Peer reviewed; Journal article, 2011-01-05)
      A severe windstorm downstream of Mt. Öræfajökull in Southeast Iceland is simulated on a grid of 1 km horizontal resolution by using the PSU/NCAR MM5 model and the Advanced Research WRF model. Both models are run with a ...

    • FLOHOF 2007: an overview of the mesoscale meteorological field campaign at Hofsjökull, Central Iceland 

      Reuder, Joachim; Ablinger, Markus; Ágústsson, Hálfdán; Brisset, Pascal; Brynjólfsson, Sveinn; Garhammer, Markus; Jóhannesson, Tómas; Jonassen, Marius O.; Kühnel, Rafael; Lämmlein, Stephan; de Lange, Tor; Lindenberg, Christian; Malardel, Sylvie; Mayer, Stephanie; Müller, Martin; Ólafsson, Haraldur; Rögnvaldsson, Ólafur; Schäper, Wolfgang; Spengler, Thomas; Zängl, Günther; Egger, Joseph (Peer reviewed; Journal article, 2012-04)
      The FLOHOF field campaign took place in the period July 21 to August 24, 2007 on and in the surroundings of Hofsjökull glacier in Central Iceland. During the campaign, 18 automatic weather stations (AWS) recording temperature, ...

    • The impact of assimilating data from a remotely piloted aircraft on simulations of weak-wind orographic flow 

      Ágústsson, Hálfdán; Ólafsson, Haraldur; Jonassen, Marius Opsanger; Rögnvaldsson, Ólafur (Journal article; Peer reviewed, 2014)
      Orographic winds near a 914 m high mountain in Southwest-Iceland are explored using unique observations made aloft with a small remotely piloted aircraft, as well as with traditional observations and high-resolution ...

    • Long-term variability of dust events in Iceland (1949-2011) 

      Dagsson-Waldhauserova, Pavla; Arnalds, Olafur; Ólafsson, Haraldur (Peer reviewed; Journal article, 2014-12-16)
      The long-term frequency of atmospheric dust observations was investigated for the southern part of Iceland and interpreted together with earlier results obtained from northeastern (NE) Iceland (Dagsson-Waldhauserova et ...

    • Multi-scale variability of winds in the complex topography of southwestern Norway 

      Jonassen, Marius Opsanger; Ólafsson, Haraldur; Reuder, Joachim; Olseth, Jan Asle (Peer reviewed; Journal article, 2012-01-02)
      Multi-scale variability of winds in the complex terrain of southwestern Norway is investigated using up to 20yr of observations from nine automatic weather stations and reanalysis data. Significant differences between the ...

    • Quantification of iron-rich volcanogenic dust emissions and deposition over the ocean from Icelandic dust sources 

      Arnalds, Olafur; Ólafsson, Haraldur; Dagsson-Waldhauserova, Pavla (Peer reviewed; Journal article, 2014-12-02)
      Iceland has extremely active dust sources that result in large-scale emissions and deposition on land and at sea. The dust has a volcanogenic origin of basaltic composition with about 10% Fe content. We used two independent ...

    • Simulations of the Bergen orographic wind shelter 

      Jonassen, Marius Opsanger; Ólafsson, Haraldur; Valved, Aslaug Skålevik; Reuder, Joachim; Olseth, Jan Asle (Peer reviewed; Journal article, 2013-10-10)
      Even though the coast of western Norway is very windy, the centre of Bergen is rather calm. To gain further understanding of this wind shelter, we study the flow in the complex topography of Bergen during two south-westerly ...