Wintertime seesaw reported


  • Anonymous


The atmospheric ‘seesaw’ between Greenland and northern Europe was more responsible for last winter's record cold in the eastern United States than any possible anthropogenic causes, according to a report at the 1977 AGU Fall Meeting.

Jeffery Rogers of the University of Colorado's Institute of Arctic and Alpine Research and Harry VanLoon of the National Center for Atmospheric Research reported that the wintertime climate of the entire northern hemisphere responds when the atmospheric seesaw modes are occurring as a result of fluctuations in the Icelandic low or Icelandic cyclone, a major atmospheric surface pressure system often noted on monthly average pressure maps. On the average this cyclone alternates between deep and shallow states in a period of just over 2 years. The pressure distribution over the entire hemisphere, particularly near the position of the North Pacific or Aleutian low, responds at the same time.