• The 11 year solar cycle UV irradiance effect and its dependency on the Pacific Decadal Oscillation 

      Guttu, Sigmund; Orsolini, Yvan J.; Stordal, Frode; Otterå, Odd Helge; Omrani, Nour-Eddine (Journal article; Peer reviewed, 2021)
      The stratospheric, tropospheric and surface impacts from the 11 year ultraviolet solar spectral irradiance (SSI) variability have been extensively studied using climate models and observations. Here, we demonstrate using ...
    • Has a warm North Atlantic contributed to recent European cold winters? 

      Keenlyside, Noel; Omrani, Nour-Eddine (Peer reviewed; Journal article, 2014-06-02)
      The rise of global surface temperature waned during the last decade, despite increasing greenhouse gas concentrations. The temperature changes were most pronounced over northern hemisphere land masses during winter (Cohen ...
    • Inconsistent Wind Speed Trends in Current Twentieth Century Reanalyses 

      Wohland, Jan; Omrani, Nour-Eddine; Witthaut, Dirk; Keenlyside, Noel (Peer reviewed; Journal article, 2019)
      Reanalysis data underpin much research in atmospheric and related sciences. While most reanalysis only cover the last couple of decades, National Oceanic and Atmospheric Administration (20CR) and European Centre for ...
    • Key Role of the Ocean Western Boundary currents in shaping the Northern Hemisphere climate 

      Omrani, Nour-Eddine; Ogawa, Fumiaki; Nakamura, Hisashi; Keenlyside, Noel; Lubis, Sandro W.; Matthes, Katja (Peer reviewed; Journal article, 2019)
      The individual impact of North Atlantic and Pacific Ocean Western Boundary Currents (OWBCs) on the tropospheric circulation has recently been studied in depth. However, their simultaneous role in shaping the hemisphere-scale ...
    • North Atlantic multi-decadal variability - mechanisms and predictability 

      Keenlyside, Noel; Ba, Jin; Mecking, Jennifer V.; Omrani, Nour-Eddine; Latif, Mojib; Zhang, Rong; Msadek, Rym (World Scientific Series on Asia-Pacific Weather and Climate, Chapter; Peer reviewed, 2015-10)
      The North Atlantic Ocean undergoes pronounced basin-wide, multi-decadal variations. The corresponding fluctuations in sea surface temperature (SST) have become known as the Atlantic Multi-decadal Oscillation (AMO) or ...
    • Ozone-induced climate change propped up by the Southern Hemisphere oceanic front 

      Ogawa, Fumiaki; Omrani, Nour-Eddine; Nishii, Kazuaki; Nakamura, Hisashi; Keenlyside, Noel (Peer reviewed; Journal article, 2015-11-23)
      The late twentieth century was marked by a significant summertime trend in the Southern Annular Mode (SAM), the dominant mode of tropospheric variability in the extratropical Southern Hemisphere (SH). This trend with ...
    • Significant multidecadal variability in German wind energy generation 

      Wohland, Jan; Omrani, Nour-Eddine; Keenlyside, Noel; Witthaut, Dirk (Peer reviewed; Journal article, 2019-09-12)
      Wind energy has seen large deployment and substantial cost reductions over the last decades. Further ambitious upscaling is urgently needed to keep the goals of the Paris Agreement within reach. While the variability in ...
    • Solar forcing synchronizes decadal North Atlantic climate variability 

      Thiéblemont, Rémi; Matthes, Katja; Omrani, Nour-Eddine; Kodera, Kunihiko; Hansen, Felicitas (Peer reviewed; Journal article, 2015-09-15)
      Quasi-decadal variability in solar irradiance has been suggested to exert a substantial effect on Earth’s regional climate. In the North Atlantic sector, the 11-year solar signal has been proposed to project onto a pattern ...