slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
El Niño and La Niña Heather Price Science Seminar January 7, 2011 SNL PowerPoint Presentation
Download Presentation
El Niño and La Niña Heather Price Science Seminar January 7, 2011 SNL

Loading in 2 Seconds...

play fullscreen
1 / 29

El Niño and La Niña Heather Price Science Seminar January 7, 2011 SNL - PowerPoint PPT Presentation


  • 63 Views
  • Uploaded on

El Niño and La Niña Heather Price Science Seminar January 7, 2011 SNL. “Australia blames 'La Niña' for epic floods” (Sydney, Jan 6, 2011). “Who's to blame for lack of snow? La Niña or Boulder City Council?” (Boulder , Colorado, Jan 6, 2011).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'El Niño and La Niña Heather Price Science Seminar January 7, 2011 SNL' - selah


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

El Niño and La Niña

Heather Price

Science Seminar

January 7, 2011

SNL

slide2

“Australia blames 'La Niña' for epic floods” (Sydney, Jan 6, 2011)

“Who's to blame for lack of snow? La Niña or Boulder City Council?” (Boulder , Colorado, Jan 6, 2011)

“Tough little girl. La Niña proves as disruptive as her better-known brother” (The Economist, Jan 6, 2011)

“La Niña Snows Make Skiers Smile” (Mt. Bachelor, Oregon , Jan 3, 2010)

slide4

Asia

South

America

Normal Conditions

upwelling

  • Strong winds from east to west over Pacific
  • Water piled up in western Pacific (~1/2 meter)
  • SST sea surface temperature in west (red=30C) and
  • cold in east (blue=22C)
  • Rainy over SE Asia, dry over S. America.
  • Upwelling off South American coast
  • Good anchovy fishing off Peru
slide5

La Niña Conditions

  • Stronger winds from east to west over Pacific
  • Water piled up in western Pacific (>1/2 meter)
  • SST sea surface temperature in west (red=30C) and cold in east (blue=22C)
  • Rainy over SE Asia, Australia dry over S. America.
  • Good anchovy fishing off Peru, from increased upwelling
  • North America (US) Forecasts
  • Heavier precipitation in Pacific Northwest, Northern Rockies, Great Lakes, Ohio valley
  • Below average precipitation in Southwest and south east states
  • Upwelling off South American coast
slide6

El Niño Conditions

No upwelling

  • Weak or even reversed winds from east to west over Pacific
  • Water no longer piled up in western Pacific
  • Warm water pool in west (30C) moves east
  • Rainy over central Pacific, flooding in Peru
  • Upwelling off South American weakens or stops
  • Really poor or no anchovy fishing off S. America, Peru
  • Positive feedback loop helps El Nino grow:
  • weaker winds warmer ocean weaker winds
slide7

Sea Level and

Sea Surface Temperature (SST)

http://www.cdc.noaa.gov/~jjb/anim.html

slide8

El Nino

La Nina

slide10

La Niño

El Niño

slide11

El Niño La Niña impacts ocean productivity

Normal Conditions and La Nina = more productive

Nutrients

El Nino Conditions = less productive

slide12

How does El Niño impact weather?

Normal/La Nina

El Nino

  • Jet stream (~12km) shifts North
  • during El Nino years (thin arrows)
  • A ridge of high pressure over North America's west coast during El Nino winters steers storms that would otherwise pass through Washington and Oregon northward toward the coast of Alaska as indicated by the big red arrow.
  • More storms develop in the Gulf of Mexico, bringing heavy rains to much of the southern United States during El Nino.
  • Strengthening of the westerlies in the Southern Hemisphere during its winter season brings heavy precipitation to parts of southern Brazil and northern Chile and Argentina.
slide14

Fires in the Amazon

El Niño plays havoc with world weather

Worsening drought in Sahel

  • Weakens Indian Monsoon.
  • Pushes mid-latitude storms poleward.
  • Causes drought in central North America.
slide15

1983 El Niño caused

severe drought, heat waves and

Bushfires in Australia.

Flames devour farmland in Victoria, Australia.

El Niño triggered prolonged drought of 1983 made fire a constant hazard. In 1983, winds whipped fires from Adelaide to Melbourne, destroying seven towns and several thousand homes.

slide16

Apparently La Niño also

plays havoc with world weather

“Australia blames 'La Niña' for epic floods” (Sydney, Jan 6, 2011)

“Who's to blame for lack of snow? La Niña or Boulder City Council?” (Boulder , Colorado, Jan 6, 2011)

“Tough little girl. La Niña proves as disruptive as her better-known brother” (The Economist, Jan 6, 2011)

“La Niña Snows Make Skiers Smile” (Mt. Bachelor, Oregon , Jan 3, 2010)

slide18

What’s happening with now

Sea Surface Temperature (SST)?

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.html

slide20

El Niño Observing System used to predict and monitor

  • Long term operational support for Pacific Ocean observations that are the foundation of accurate El Nino forecasts:
    • Moored buoysDrifting buoysVolunteer ship temperature probesSea level measurements
  • Total cost of these ocean observations is $4.9 million per year
slide21

November 4, 2010

ENSO Alert System Status:La Niña is expected to last at least into the Northern Hemisphere spring 2011. Consistent with nearly all ENSO forecast models, La Niña is expected to last at least into the Northern Hemisphere spring 2011. A large majority of models also predict La Niña to become a strong episode (defined by a 3-month average Niño-3.4 index of –1.5oC or colder) by the November-January season before gradually weakening. A few of the models, including the NCEP Climate Forecast System (CFS), suggest that La Niña could persist into the Northern Hemisphere summer 2011. However, no particular outcome is favored beyond the Northern Hemisphere spring due to large model disagreement and lower model skill during the period.

Likely La Niña impacts during November 2010-January 2011 include suppressed convection over the central tropical Pacific Ocean, and enhanced convection over Indonesia. Expected impacts in the United States include an enhanced chance of above-average precipitation in the Pacific Northwest, Northern Rockies (along with a concomitant increase in snowfall), and Ohio Valley, while below-average precipitation is most likely across the south-central and southeastern states.

Climate Prediction Center web page: http://www.cpc.ncep.noaa.gov

slide25

In recent years El Niño events have occurred more frequently as the global temperature anomalies associated with each El Niño increase.

  • Extreme regional weather and climate anomalies associated with El Niño are being exacerbated by increasingly higher temperatures.
  • The warmer conditions are linked to higher concentrations of atmospheric greenhouse gases.

National Climatic Data Center, Asheville, NC

slide26

Bleached Coral

El Niño impacts on Coral Reefs

Healthy Coral

During El Nino years ocean temperatures rise causing coral bleaching.

  • Coral Bleaching
  • Occurs when coral polyps expel their colorful symbiotic zooxantheallae algae.
  • Warmer ocean temperatures just 2 degree C above average cause bleaching.
  • The algae photosynthesize organics for the coral polyps while the polyps provide nutrients for the algae.
  • Coral polyps die within weeks if the algae does not return.
slide27

Healthy Coral

What’s so special about Coral Reefs?

  • Coral reefs are Rainforests of the Ocean
  • Reefs cover only 0.2% of ocean’s area but are:
    • some of the Earth’s most diverse living ecosystems;
    • habitat for 1/3 of marine fish and tens of thousands of other species (turtles, eel, marine mammals, etc);
    • nurseries for non-reef dwelling species;
    • support local economies, fisheries and tourism;
    • protect shorelines and coastal communities from
    • storms, wave damage and erosion;
    • generate beach sand;
    • Full of new and undiscovered biomedical resources that we've only just begun to explore.
slide28

Coral Bleaching past 15 years

Source: ReefBase 2008

"It's a scary picture from what we've seen. Over the last 15 years, the Northern Hemisphere tropical temperatures have gone up by ½ degree Fahrenheit.”

“The problem is if we have another few episodes (of bleaching) like we did a few years ago, when the temperatures get too high for too long, we're limited to what we can do.“ Alan Strong of NOAA

slide29

Coral Reefs provide valuable clues

  • record of El Nino events for past 130,000 yrs
  • most intense El Nino events occurred in past 100 yrs
  • two strongest El Nino were 1982 & 1997
  • bleaching is considered “canary in coal mine” for
  • climate change

How do we study Corals?

Corals record changes in local rainfall and temperature in the ratio of two isotopes of oxygen incorporated in their calcium carbonate skeletons.

Cores are drilled through boulder-size corals and successive thin slices reveal the change in oxygen composition - and climate - back in time.