Large-scale, free Rossby waves in the atmosphere—an update

The existence of free, or normal mode Rossbywaves has been known for 50 yr. Studies have indicated that they can affect the large-scale flow in important ways; nevertheless there has been little written on them during the last decade. Here, evidence of their presence in a 40-yr record of NCEP/NCAR Reanalysis data is presented. It provides a starting point from which other published observations based on varying data sets are summarized. In addition, literature pointing to their possible effects is summarized. This update is submitted in the hopes that it will reinvigorate interest that can increase our understanding of variations in the large scales