Extreme Weather/Climate

L. David Roper
6 April, 2016

"Climate is what you expect; weather is what you get."



One definition of climate is " the composite or generally prevailing weather conditions of a region, as temperature, air pressure, humidity , precipitation, sunshine , cloudiness, and winds, throughout the year, averaged over a series of years." So, extreme climate is a compilation of extreme weather over a series of years.

The Intergovernmental Panel on Climate Change, which consists of thousands of climatologists, has given predictions of extreme weather events due to global warming in the 2007 report. Here is a summary:

The year 2010 slightly exceeded 2005 as the hottest year on record; it will probably go down in history as the year when it was realized by most of the public that extreme weather was evidence of global warming:

U.S. Climate Extremes Index

NOAA has devised a Climate Extremes Index (CEI) for the United States:

The dip from ~1950 to ~1980 was due to global dimming due to aerosols in the atmosphere due to fossil-fuels burning before clean-air legislation:

I have done a study of the increase in tornadoes over time in the United States.

U.S. Weather/Climate Disasters and Costs

Jet Stream

Both the northern and southern hemispheres have polar jet streams (altitude 7-12 km = 23,000-39,000 ft) and subtropical jet streams (altitude 10-16 km = 33,000-52,000 ft) that move from west to east at varying speeds up to nearly 400 km/hr = 249 mi/hr = 216 knots.

Jet streams stear storm systems in the lower atmosphere, so it is important as to the paths that they follow.

Research has begun on how the jet streams' paths are changed by global warming. Data indicate that the jet streams are slowly rising in altitude and moving toward the poles, but are dipping into the deep south during winters causing severe winter weather. The movement toward the poles means that the dry areas are moving toward the poles.

The increased temperatures in the arctic regions cause high pressure there, which causes the jet stream to dip into lower latitudes bringing cold arctic air with it. So both North America and Australia can have cold winters with much frozen precipitation. (Current Weather Blast Likely Intensified by Rising Global Temps)

Changing Jet Streams May Alter Paths of Storms and Hurricanes.

The precipation increases because the higher global temperatures evaporates more water into the atmosphere. Also, see this.


L. David Roper interdisciplinary studies
Roper Global Warming

L. David Roper, http://www.roperld.com/personal/roperldavid.htm
6 April, 2016