Weather and Climate

• “Weather” - tropospheric events associated with atmospheric flows of few 100 m & few days or less

• Weather phenomena - chaotic, but atmospheric data averaged over a month - more regular

• But exists interannual variability

• “Climate” - state of the atmosphere averaged over several years +: the expected weather for a particular time of year.

• It is determined by the boundary conditions of the atmosphere-ocean system:

  • solar irradiance (power output of the sun)
  • atmospheric composition (greenhouse gases...)
  • positions of continents, ice-sheets etc.