El-Nino Conditions (a) Under ordinary conditions, higher pressure

El-Nino Conditions (a) Under ordinary conditions, higher pressure over the southeastern Pacific and lower pressure near Indonesia produce easterly trade winds along the equator. These winds promote upwelling and cooler ocean water in the eastern Pacific, while warmer water prevails in the western Pacific. The trades are part of a circulation (called the Walker circulation) that typically finds rising air and heavy rain over the western Pacific and sinking air and generally dry weather over the eastern Pacific. When the trades are exceptionally strong, water along the equator in the eastern Pacific becomes quite cool. This cool event is called La Nino (b) During El Nino conditions atmospheric pressure decreases

over the eastern Pacific and rises over the western Pacific. This change in pressure causes the trades to weaken or reverse direction. This situation enhances the countercurrent that carries warm water from the west over a vast region of the eastern tropical Pacific. The thermocline, which separates the warm water of the upper ocean from the cold water below, changes as the ocean conditions change from non-El Nino to El Nino. El-Nino Conditions (a) Average sea surface temperature departures from normal as measured by satellite. During El Nino conditions upwelling is greatly

diminished and warmer than normal water (deep red color) extends from the coast of South America westward, across the Pacific. (b) During La Nina conditions, strong trade winds promote upwelling, and cooler than normal water (dark blue color) extends over the eastern and central Pacific. El-Nino Conditions Typical winter weather patterns across North America during an El Nino warm event (a) and during a La Nina cold event (b). During El Nino conditions, a persistent trough of low pressure forms over the north Pacific and, to the south of the low, the jet stream (from off the Pacific) steers wet weather and storms into California and the southern part of the

United States. During La Nina conditions, a persistent high-pressure area forms south of Alaska forcing the polar jet stream and accompanying cold air over much of western North America. The southern branch of the polar jet stream directs moist air from the ocean into the Pacific Northwest, producing a wet winter for that region. El-Nino Conditions The Ocean Nino Index (ONI). The numbers on the left side of the diagram represent a running 3month mean for sea surface temperature variations (from normal) over the tropical Pacific Ocean from latitude 5 N to 5 S and from longitude 120 W to 170 W. Warm E1 Nino episodes are in red; cold La Nina episodes are in blue. Warm and cold events occur when the deviation from the normal is 0.5 or

greater. An index value between 0.5 and 0.9 is considered weak; an index value between 1.0 and 1.4 is considered moderate, and an index value of 1.5 or greater is considered strong. El-Nino Conditions Regions of climatic abnormalities associated with El NinoSouthern Oscillation conditions (a) during December through February and (b) during June through August. A strong ENSO event may trigger a

response in nearly all indicated areas, whereas a weak event will likely play a role in only some areas. El-Nino Conditions Typical winter weather patterns across North America during an El Nino warm event (a) and during a La Nina cold event (b). During El Nino conditions, a persistent trough of low pressure forms over the north Pacific and, to the south of the low, the jet stream (from off the Pacific) steers wet weather and storms into California and the southern part of the United States. During La Nina conditions, a persistent high-pressure area forms south of Alaska forcing the polar jet stream and accompanying cold air over much of western North America. The southern branch of the polar jet stream directs moist air from the ocean into the Pacific Northwest, producing a wet winter for that region.

Recently Viewed Presentations

  • Informational Webinar Slides

    Informational Webinar Slides

    At least one team member attends an online informational webinar. November 2017. Participate in monthly webinars. Beginning December 2017. Regularly meet as a team to implement interventions and monitor performance. December 2017 until the end of project. Complete survey assessments...
  • ANALOGY ESSAY - Luzerne County Community College

    ANALOGY ESSAY - Luzerne County Community College

    ANALOGY ESSAY PRE-WRITING THE PROCESS ANALOGY ESSAY PROCESS: First, choose a subject that concerns you: Some issue in your career field, from personal experience, or of national concern politics, war, economy, history, education This will be your "Subject X" *...
  • BMPTRAINS Model: Background information on swales

    BMPTRAINS Model: Background information on swales

    From BMPTRAINS Model (FDOT and UCF) Differences between rainfall and stormwater harvesting. ... For Harvesting Recommend Filtrationby Horizontal Well, disc filter or Sand Filtration(Horizontal well less cone of depression) PUMP lift is limited to 20 feet. Some Definitions.
  • Intro to Schoolnet - IUSD Librarian Intranet

    Intro to Schoolnet - IUSD Librarian Intranet

    The "forget password" may be disabled if your district uses single sign-on, e.g., same username for the district and Schoolnet. On your own computer, bookmark the site for later. * Tell participants to think of My Schoolnet as Schoolnet's version...
  • Shop tools & Supplies

    Shop tools & Supplies

    Shop tools & Supplies Ag Mechanics Tool ID Gloves "PPE" Safety Glasses "PPE" Needlenose Pliers Hearing Protection "PPE" Combination Square Drill + Drill Press Drill bits Angle Grinder Diagonal or Side-cutting Pliers Bench Grinder Chop Saw Band Saw Tap +...
  • November 2015 Shrinking, Flexible & Focused: The Future

    November 2015 Shrinking, Flexible & Focused: The Future

    The Grand Central event was an extension of the social media strategy within the brand's repositioning campaign. Dubbed #WeighThis, from the 360i agency, the social push kicked off in late June. That was followed in early July by a new...
  • classify matter by physical properties, including shape, relative

    classify matter by physical properties, including shape, relative

    identify factors in the environment, including temperature and precipitation, that affect growth and behavior such as migration, hibernation, and dormancy of living things.[2.9B] October 2014. Elementary Science - 2nd Grade
  • Beyond Articles - University College London

    Beyond Articles - University College London

    Publishing Official Datasets Toby Green OECD Publishing 4th Bloomsbury Conference on e-Publishing and e-Publications 24th and 25th June , 2010 Publishing Official Data in cool ways since 1961 Climategate! "investigation reveals scientific concern about missing tree ring data".