1 / 16

Chapter 8

Chapter 8 . Wind and Weather. Three main concepts in this chapter: Movement of air Wind Monitoring the wind. What moves the air? Pressure gradient (PG) Coriolis Effect Friction. Pressure Gradient – Horizontal motion is our concern. Caused by unequal heating of surfaces

jela
Download Presentation

Chapter 8

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 8 Wind and Weather

  2. Three main concepts in this chapter: • Movement of air • Wind • Monitoring the wind

  3. What moves the air? • Pressure gradient (PG) • Coriolis Effect • Friction

  4. Pressure Gradient – • Horizontal motion is our concern • Caused by unequal heating of surfaces • (albedo, land/water, sun angle) • A true force: motion is from high • pressure to low pressure all over earth • A greater PG, then a greater wind speed

  5. Isobars are close together on a map • showing a high gradient and stronger • wind

  6. Coriolis Effect– • Not a true force, but an apparent • force. • Increases as latitude increases. • Zero deflection at the equator. • Increase wind, increase Coriolis.

  7. Caused by earth’s rotation (winds deflected to the right in the N hemisphere and to the left in the S hemisphere). NSIDC (Ball activity here)

  8. Friction – • Reduces Coriolis; slows wind at • lower levels (surface). • At surface, pressure prevails. Winds • follow PG.

  9. Geostrophic Winds vs. Surface Winds Geostrophic winds are winds that flow aloft, above the surface; so no effect. Friction is gone, PG and Coriolis are balanced. Airflow is parallel to isobars and straight.

  10. Wind – • Motion of the air. • Forces all joining together.

  11. Monitoring the Wind - • Instruments used?

  12. Winds aloft are affected by winds at • the surface and vice versa – • Lows at surface have converging winds, • and aloft they are diverging. Elongated • regions are called “troughs.” • Highs at surface have diverging winds, • and aloft they are converging. Elongated • regions are called “ridges.” • When growth occurs, so do storms.

  13. Buys-Ballots Law – • Northern HS: • Put back to the wind. Rotate 45° to right. • Low pressure is to your left and high • pressure is to your right. ALWAYS works! • Check the local pressure maps to verify.

More Related