Weather forecasting Forecasting difficulty Crystal ball Commentary

Vilhelm Bjerknes, Jacob Bjerknes atmospheric sciences

Weather forecasting

• Vilhelm Bjerknes believed a mathematical model
• could help predict the weather.
• Existing models were not adequate,
• so he combined fluid dynamics with thermodynamics.
• His equations, applied to oceanic and atmospheric
• motions, made modern weather forecasting feasible.
• After World War I, he and his son, Jacob,
• working together on the life-cycle of mid-latitude cyclones,
• realized that most weather activity,
• borrowing a concept from the war,
• happens at the fronts—
• at the boundaries between air masses.

Forecasting difficulty

• Step out from under the trees to check for clouds.
• Wet a finger in your mouth then raise it in the air;
• which side is cooler tells the direction of the wind.
• Otherwise, in trying to predict the weather, it is difficult
• to get good data, difficult to model atmospheric and oceanic processes,
• and difficult to put it all together in a reasonable time.
• To make matters worse, weather is chaotic,
• so the further into the future you try to predict
• the less accurate your predictions will turn out to be.

Crystal ball

• If you had a crystal ball
• would you use it to get rich
• or would you try to help others?
• Would people believe you?
• Would you try to convince them?
• Would knowing give you the means
• of making things better for everyone?
• Could you alter the future, really,
• or would your trying to do so already be a part
• of what your crystal ball would show you?