ATM OCN (Meteorology) 100

PLANETARY SCALE CIRCULATION 
(continued)
PART II: THE JET STREAM & THE CIRCUMPOLAR VORTEX

Summer 1999

Lecture #18 Scheduled for:

15 JUL 1999 (R)

Recommended Readings from Moran and Morgan (1997):

pages 240-243; 234-240.

Objectives:

• To explain the cause of the thermal-wind relation and identify the characteristics.
• To explain why the midlatitude flow aloft is predominantly westerly, with upper tropospheric jet streams, located over the near surface polar front.
• To identify the thermal distribution and regions of an upper atmospheric wave.
• To describe the seasonal variation in the circumpolar vortex.

Today's Lecture Outline:

A. INTRODUCTION

• Definition and significance
• Discovery of the Jet Stream

B. ANATOMY OF THE JET STREAM

• Jet Stream Structure
• Types of Major Jet Streams
• Seasonal Variations in Jet Streams
• Reasons for Jet Streams
• The Thermal Wind Relationship

C. WAVES IN THE WESTERLIES

• The Circumpolar Vortex
• Observed Wave Features in The Circumpolar Vortex
• Long Planetary or Rossby Waves
• Seasonal Variations in the Circumpolar Vortex

Last revision 26 May 1999