Sudden cosmic ray decreases: No change of global cloud cover

Currently a cosmic ray cloud connection (CRC) hypothesis is subject of an intense controversial debate. It postulates that galactic cosmic rays (GCR) intruding the Earth's atmosphere influence cloud cover. If correct it would have important consequences for our understanding of climate driving processes. Here we report on an alternative and stringent test of the CRC‐hypothesis by searching for a possible influence of sudden GCR decreases (so‐called Forbush decreases) on clouds. We find no response of global cloud cover to Forbush decreases at any altitude and latitude.

[1]  D. Kniveton,et al.  Cosmic ray decreases and changes in the liquid water cloud fraction over the oceans , 2009 .

[2]  H. Svensmark,et al.  Cosmic ray decreases affect atmospheric aerosols and clouds , 2009 .

[3]  Kristján Jónasson,et al.  Cosmic rays, cloud condensation nuclei and clouds – a reassessment using MODIS data , 2008 .

[4]  I. Usoskin,et al.  Variations of aerosol optical properties during the extreme solar event in January 2005 , 2008 .

[5]  F. Arnold.  Atmospheric Ions and Aerosol Formation , 2008 .

[6]  T. Sloan,et al.  Testing the proposed causal link between cosmic rays and cloud cover , 2008, 0803.2298.

[7]  L. Desorgher,et al.  The extreme solar cosmic ray particle event on 20 January 2005 and its influence on the radiation dose rate at aircraft altitude. , 2008, The Science of the total environment.

[8]  F. Arnold.  Atmospheric Aerosol and Cloud Condensation Nuclei Formation: A Possible Influence of Cosmic Rays? , 2007 .

[9]  M. Gurtner,et al.  Atmocosmics:. a Geant 4 Code for Computing the Interaction of Cosmic Rays with the Earth's Atmosphere , 2005 .

[10]  E. Lovejoy,et al.  Tropospheric ionization and aerosol production: A model study , 2004 .

[11]  M. Todd,et al.  Short-term variability in satellite-derived cloud cover and galactic cosmic rays: an update , 2004 .

[12]  I. Usoskin,et al.  Latitudinal dependence of low cloud amount on cosmic ray induced ionization , 2004, physics/0407066.

[13]  K. Froyd,et al.  Atmospheric ion‐induced nucleation of sulfuric acid and water , 2004 .

[14]  J. M. Reeves,et al.  Particle Formation by Ion Nucleation in the Upper Troposphere and Lower Stratosphere , 2003, Science.

[15]  P. Laut.  Solar activity and terrestrial climate: an analysis of some purported correlations , 2003 .

[16]  J. Kristjánsson,et al.  Solar activity, cosmic rays, clouds and climate – an update , 2003 .

[17]  H. Svensmark,et al.  Galactic cosmic ray and El Nino Southern Oscillation trends in International Satellite Cloud Climatology Project D2 low-cloud properties , 2003 .

[18]  Eigil Kaas,et al.  A new look at possible connections between solar activity, clouds and climate , 2002 .

[19]  J. Kirkby,et al.  Cosmic Rays, Clouds, and Climate , 2002, Science.

[20]  R. Bradley,et al.  Solar influences on cosmic rays and cloud formation: A reassessment , 2002 .

[21]  F. Arnold,et al.  Cosmic ray‐induced aerosol‐formation: First observational evidence from aircraft‐based ion mass spectrometer measurements in the upper troposphere , 2002 .

[22]  Petra M. Udelhofen,et al.  Cloud cover variations over the United States: An influence of cosmic rays or solar variability? , 2001 .

[23]  Richard P. Turco,et al.  From molecular clusters to nanoparticles: Role of ambient ionization in tropospheric aerosol formation , 2001 .

[24]  D. Livingstone,et al.  Some results relevant to the discussion of a possible link between cosmic rays and the Earth's climate , 2001 .

[25]  P. Farrar.  Are Cosmic Rays Influencing Oceanic Cloud Coverage – Or Is It Only El Niño? , 2000 .

[26]  H. Cane.  Coronal Mass Ejections and Forbush Decreases , 2000 .

[27]  H. Svensmark,et al.  Low cloud properties influenced by cosmic rays , 2000, Physical review letters.

[28]  W. Rossow,et al.  Advances in understanding clouds from ISCCP , 1999 .

[29]  J. Haigh,et al.  Some doubts concerning a link between cosmic ray fluxes and global cloudiness , 1999 .

[30]  Henrik Svensmark,et al.  Variation of cosmic ray flux and global cloud coverage—a missing link in solar-climate relationships , 1997 .

[31]  C. Butlerb,et al.  The possible connection between ionization in the atmosphere by cosmic rays and low level clouds , 2004 .