Source: Joint Institute for the Study of Atmosphere and Ocean: http://www.atmos.washington.edu/pdo |
| Winds from the Pacific Ocean bring moist air to the Rockies.
When the sea surface is warm, more water evaporates
from the sea and makes its way to the Rockies. |
|
| In 1976 there was a major change in the
ocean and atmospheric circulation in the
northern Pacific Ocean. |
|
| This brought less snow to the Rockies.
The circulation changed back again in the
late 1990s and brought drought to the prairies. |
|
|
Demuth and Keller (2002)
|
