Basic Meteorology Dr. Kevin Kloesel National Press Foundation March 12, 2007

Some analogies with the human body…. Blood pressure: hypertensive versus normal

On any given day…or two

GOALS: Earth’s rotation on its axis Earth’s rotation (orbit) around the Sun Patterns of Uneven Heating Patterns of Pressure Patterns of Weather!

Equatorial (Tropical) Regions Polar Regions

The uneven heating should produce a global temperature pattern that looks like this... Does it?

Quantitative Temperature measurements look like this... WHY?

And in July….

Mean annual temperature by latitude (shading indicates variability) Note! Be careful with graphs like this!

Coriolis Force An apparent force due to the earth’s rotation. Found in all moving reference systems. Occurs when reference systems interact. Ever tried to throw a ball on a rotating disk?

Polar Stereographic Projection - Northern Hemisphere The real world - Notice the global “connectivity”

Notice the “ridge” in the Central Plains and the “troughs” in the east and west. The trough is where you observe low 500mb heights (low thickness values and cold temps.). The ridge is where the highest thickness values (and highest temps.) are observed.

TROUGH ‘TROF’ TROUGH RIDGE

Anomalies are departures from normal. In this case, the warm colors indicate above normal, and the cold colors indicate below normal. Notice the alternating pattern as you move around the pole. These data are from May 2001.

Air Mass Classification

A global composite water vapor image.

SO MUCH COMPLEXITY SO MUCH TO LEARN IT’S ALL ABOUT RESOLUTION!

VOXELS mapped into PIXELS, at different resolution.

Review! The Earth is round, spins, orbits an energy source, and is tilted on its axis at 23.5 degrees. Therefore, we have cold (dense) air at the poles, and warm (less dense) air in the tropics. Cold air takes up less space (more dense) than warm air. The Earth is constantly trying to reach an equilibrium (moving warm air poleward and cold air equatorward). Ever-changing ingredients stirred by troughs and ridges bring the changing weather conditions that we observe on Earth.

Review cont! Ridge-trough patterns exist around the Earth and are connected in a circumpolar fashion in each hemisphere. Therefore, pattern changes in one region can impact the weather in others. Ridge-trough patterns result in the migration of air masses around the planet. Air mass boundaries are called fronts, and tend to be the focus for storms and precipitation.

BREAK TIME! Please do not hesitate to me with any questions Kevin Kloesel