The Physical Geography of North America

By Antony R. Orme | Go to book overview

5
Dynamic and Synoptic Climatology
Roger G. Barry

Tectonic processes and subsequent geologic history have established the continental framework of North America, but it is the interaction of the coupled atmosphere—ocean system with this framework that generates its climate. In turn, climatic conditions greatly influence the hydrologic cycle, vegetation cover, and soils discussed in subsequent chapters. The climate has also changed over time, most dramatically after the disappearance of the last Laurentide Ice Sheet and associated Cordilleran ice caps and glaciers between about 12,000 and 8,000 years ago (see chapters 2– 4). Subsequent centennial- and multidecadal-scale climatic fluctuations, evidenced by neoglacial episodes in the Western Cordillera and recurrent episodes of severe drought in the western United States, have been no less important, however, in human affairs.

This chapter surveys the dynamic and synoptic aspects of North America's present climate, namely, the planetaryscale controls of atmospheric circulation and the embedded synoptic weather systems, recurrent mesoscale phenomena, and the resulting climatic conditions that affect the continent. The discussion is organized according to four topics: the planetary-scale setting, continental-scale influences and their climatic effects, synoptic regimes, and regional climatic features and anomalies. We begin by considering the overall climatic setting of the continent.

The climate of North America is shaped by geographical, oceanographic, and atmospheric factors and their interactions. The continent and adjacent Canadian Arctic Archipelago extend approximately from 15° to 80°N, and from 170°W in Alaska to 50°–60°W in eastern Canada, narrowing to between 120°W in southern California and 80°W in Florida before tapering southward through Mexico. High mountains along the continent's west coast join with intermontane plateaus and the Rocky Mountains farther east to form the Western Cordillera that extends southward from Alaska to Mexico. Mountains also dominate the eastern Canadian Arctic Archipelago and Labrador. The Arctic Ocean and year-round sea ice are key factors in the climate of the Canadian Arctic Archipelago and northern Alaska. The west coast waters are cold as a result of the southwardflowing California Current, whereas the warm Gulf Stream follows the Atlantic coast of the United States. However, the western Baffin Bay—Labrador Current transports subpolar water and, in late winter and spring, sea ice and icebergs southward to 48°W off Newfoundland. Maritime influences are also present in the heart of the continent in summer and autumn around Hudson Bay and the Great Lakes, as well as more generally as a result of the large number of smaller lakes and bogs in the boreal forest of Canada and the mixed forest of the upper Midwest. Until now, the effects of these smaller water bodies have not been represented in general atmospheric circulation models. The Gulf of Mexico is a prominent factor in the climate of the southern and southwestern United States and much of

-98-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this book

This book has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this book

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited page

Bookmark this page
The Physical Geography of North America
Table of contents

Table of contents

Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
/ 551

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.