1. El Nino La nina & The Southern Oscillation ENSO by ROBERT PERRY
WELCOME TO OUR BASIC INTRODUCTION TO EL NINO, LA NINA AND THE SOUTHERN OSCILLATION.
by ROBERT PERRY

2. The images, maps and diagrams in this presentation were taken from
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wide web. Any privately owned
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project will gladly be removed.
LEGAL BUT IMPORTANT INFORMATION. THANK YOU.

3. PEOPLE ARE GENERALLY MORE AWARE OF EL NINO WHEN THEY EXPERIENCE HEAVY RAINS AND THEIR AFTERMATH.

4. PACIFIC COAST HIGHWAY, NEAR MALIBU CALIFORNIA.
HERE WE SEE THE PACIFIC COAST HIGHWAY IN MALIBU, CALIFORNIA, BLOCKED BY A LANDSLIDE INDUCED BY HEAVY EL NINO RAINS.
PACIFIC COAST HIGHWAY, NEAR MALIBU CALIFORNIA.

5. El Nino WHEN SEVERE RAIN AND OCEAN DISTURBANCES PERIODICALLY
IN SPANISH, EL NINO MEANS “The Child” WITH A CAPITOL “C,” REFERRING TO THE BABY JESUS. WHAT DID THE CHRIST CHILD HAVE TO DO WITH THE NAME OF THIS OCEAN-ATMOSPHERE PHENOMENON? IT’S ORIGINAL NAME WAS GIVEN BY PERUVIAN COASTAL INHABITANTS AND FISHERMEN WHO NOTICED A PERIODIC RECURRENCE OF WARM OCEAN WATER AND A CORRESPONDING DECLINE IN PREFERRED FISH SPECIES. SINCE THE EFFECTS WERE MOST COMMON AROUND CHRISTMAS, THE NAME “El Nino” WAS GIVEN.
WHEN SEVERE RAIN AND OCEAN
DISTURBANCES PERIODICALLY
HIT THE COAST OF PERU MOST
DRAMATICALLY IN LATE DECEMBER,
COINCIDING WITH CHRISTMAS,
THE EVENT BECAME KNOWN AS
EL NINO, WHICH MEANS “THE
CHRIST CHILD.”

6. PREVAILING SURFACE CURRENTS IN THE TROPICAL EAST PACIFIC REGION
EQUATORIAL TRADE WINDS BLOWING FROM EAST TO WEST PUSH SURFACE WATERS ACROSS THE PACIFIC DURING NORMAL YEARS.
PREVAILING SURFACE CURRENTS IN
THE TROPICAL EAST PACIFIC REGION

7. MEASURING AND PREDICTING The Southern Oscillation
El Nino, La Nina and
The Southern Oscillation
1. BUOY DATA
HOW DO SCIENTISTS GATHER DATA ABOUT EL NINO?

8. The Tropical Atmosphere Ocean (TAO) Project
MOORED BUOYS WITH BOTH WEATHER AND OCEAN SENSORS UPLOAD THEIR DATA TO SATELLITES.

9. ARGOS satellite Moored buoy
THIS DIAGRAM SHOWS HOW MOORED BUOYS MAY BE CONFIGURED.

10. THIS MAP SHOWS THE POSITION OF BUOYS THAT HAVE BEEN DEPLOYED ACROSS THE TROPICAL PACIFIC TO STUDY EL NINO.

11. HOT
POOL
COLD
TONGUE
UNDER “NORMAL” CONDITIONS, THE TROPICAL TRADE WINDS CAUSE WARM SURFACE WATERS TO ACCUMULATE IN THE WESTERN PACIFIC. NOTICE ALSO THAT THE HUMBOLDT CURRENT WHICH RUNS UP THE COAST OF SOUTH AMERICA BRINGING COLD WATER TOWARDS THE EQUATOR, CREATES A COLD TONGUE AS IT MOVES AWAY FROM LAND.

12. HOT POOL COLD TONGUE NORMAL UPWELLING “NORMAL” CONDITIONS
IN THIS 3-DIMENSIONAL DISPLAY SEVERAL INTERESTING THINGS CAN BE DEDUCED ABOUT THE TROPICAL PACIFIC DURING A “NORMAL” YEAR. FIRST, THE COLD TONGUE FROM THE NORTH-FLOWING HUMBOLDT CURRENT CAN BE SEEN. SECOND, THE WATER IN THE TONGUE MOVING AWAY FROM LAND CAUSES AN UPWELLING OF DEEP, COLD, NUTRIENT RICH WATER TO REPLACE THE SHIFTING SURFACE WATER. THIS IS GOOD FOR PERUVIAN FISHERIES.
FINALLY, THIS ILLUSTRATION SHOWS HOW THE SEA SURFACE EXPANDS AND BECOMES ELEVATED. THE COLD WATER TONGUE, ON THE OTHER HAND, CONTRACTS AND CAUSES THE SEA SURFACE TO DEPRESS.
NORMAL
UPWELLING
“NORMAL” CONDITIONS

13. HOT POOL SHIFTS EAST NO COLD TONGUE
IN THESES NEXT SLIDES WE’LL LOOK AT THE SAME KINDS OF DATA DISPLAYED DURING AN EL NINO TIME PERIOD. HERE WE SEE THAT THE NORMAL WEST-TO-EAST BLOWING TRADE WINDS HAVE DECLINED AND THE POOL OF WARM WATER THAT TYPICALLY RESIDES ON THE WESTERN SIDE OF THE EQUATOR HAS BEEN ALLOWED TO FLOW BACK TOWARDS NORTH AND SOUTH AMERICA. THIS CANCELS THE NORMAL COLD TONGUE OF WATER FROM THE HUMBOLDT GYRE.

14. HOT POOL SHIFTS EAST NO COLD TONGUE NO UPWELLING EL NINO CONDITIONS
EL NINO CONDITIONS: AS THE WARMER-THAN-NORMAL WATER APPROACHES THE WEST COAST OF THE AMERICAS, THE THERMOCLINE TAKES A DRASTIC DIVE AND SHUTS DOWN THE UPWELLING PROCESS WHICH BRINGS NUTRIENTS TO THE SURFACE AND FUELS THE FOOD WEB. THIS IS NOT GOOD FOR PERUVIAN FISHERIES. NO
UPWELLING
EL NINO CONDITIONS

15. HOT POOL SHIFTS WEST EXTENDED COLD TONGUE
NOW THE COLD SISTER OF EL NINO, THE ALTERNATE PHASE OF THE OSCILLATION PATTERN, LA NINA BEGINS. TRADE WINDS BLOW STRONG AND PUSH WARM WATERS FAR TO THE WEST. THE COLD TONGUE OF THE HUMBOLDT GYRE EXTENDS MORE THAN HALF WAY ACROSS THE EQUATOR.

16. HOT POOL SHIFTS WEST EXTENDED COLD TONGUE HUGE UPWELLING
LA NINA CONDITIONS: DEPRESSED SEA LEVELS CREATE A HUGE UPWELLING. VAST AMOUNTS OF DEEP, COLD AND NUTRIENT RICH BOTTOM WATERS ARE RETURNED TO THE ILLUMINATED SURFACE. PHOTOSYNTHESIS RATES SKYROCKET, AND THE FOOD WEB IN THE OCEAN NEAR PERU BLOSSOMS. MEANWHILE THE HOT, ELEVATED SURFACE WATERS AND ALL THEY BRING WITH THEM LIE TO THE FAR WEST.
HUGE
UPWELLING
LA NINA CONDITIONS

17. SST’s (OC)
IN SUMMARY, HERE IS A LOOK AT EL NINO AND LA NINA (THE SOUTHERN OSCILLATION) SURFACE WATER TEMPERATURES SIDE BY SIDE. REMEMBER WHERE THE HOT AND COLD WATER IS DURING EACH PHASE OF THE CYCLE.

18. ENSO LINKING ATMOSPHERE AND OCEAN
NEXT WE SHALL SEE WHAT HOT AND COLD WATER DOES TO OUR ATMOSPHERE AND ITS WEATHER PATTERNS.

19. Storms move westward STRONG UPWELLING South America Australia
SO HERE’S THE WAY IT WORKS: HOT WATER EVAPORATES AND SENDS A LOT OF MOISTURE INTO THE ATMOSPHERE. THIS RETURNS TO THE SURFACE AS RAINFALL. ON THE OTHER HAND, COLD WATERS EVAPORATE VERY LITTLE AND CARRY NO MOISTURE INTO THE ATMOSPHERE. CONDITIONS ARE DRY. HOT WATER MEANS WET, COLD MEANS DRY. SO IN THIS ILLUSTRATION, A LA NINA PERIOD, THE HOT WATER POOL IN THE WEST MEANS HIGHER THAN NORMAL RAINFALL THERE, WHILE COLD WATERS TO THE EAST SPELL DROUGHT FOR THE AMERICAS.
South
America
Australia
STRONG
UPWELLING

20. Walker circulation Region of Upwelling South America Australia
UNDER “NORMAL” CONDITIONS, OR MORE ACCURATELY THE PERIOD BETWEEN EXTREME OSCILLATIONS, WARM WATER MOVES MORE THAN HALF WAY ACROSS THE EQUATOR TO THE EAST, BRINGING RAIN WITH IT. UPWELLINGS DUE TO THE MOVEMENT OF THE COLD TONGUE OFF SOUTH AMERICA IS GOOD.
South
America
Australia
Region of Upwelling

21. Storms move eastward Upwelling suppressed South America Australia
DURING EL NINO THE HOT WATER AND RAIN MOVE EAST. UPWELLING IS SHUT DOWN.
South
America
Australia
Upwelling suppressed

22. BIOLOGICAL IMPORTANCEof
UPWELLING
ONE OF THE MOST IMPORTANT BIOLOGICAL SIDE EFFECTS OF EL NINO, LA NINA AND THE SOUTHERN OSCILLATION HAS TO DO WITH AN OCEAN CIRCULATION PROCESS KNOWN AS UPWELLING. SIMPLE PUT, UPWELLING IS A VERTICAL WATER CURRENT COMING FROM THE DEEP AND DIRECTED TOWARDS THE SURFACE. WATER MOVING UP…THAT’S WHY IT IS CALLED UPWELLING. UPWELLING IS CAUSED BY WATER MOVING AWAY FROM THE LAND, OR TWO WATER MASSES MOVING APART. DIVERGING WATER MASSES CAN OCCUR ALONG THE EQUATOR DUE TO CORIOLIS EFFECTS, THE OCEAN GYRES CIRCULATE CLOCKWISE IN THE NORTHERN AND COUNTER CLOCKWISE IN THE SOUTHERN HEMISPHERE. SO IN EQUATORIAL REGIONS THEY MOVE AWAY FROM EACH OTHER CREATING A “VOID” TO BE FILLED BY WATER COMING UP FROM BELOW. IN COASTAL WATERS UPWELLING MAY OCCUR DUE TO CORIOLIS EFFECTS TOO, FOR EXAMPLE THE CALIFORNIA CURRENT MOVING FROM NORTH TO SOUTH NATURALLY TENDS TO BE DEFLECTED IN A CLOCKWISE DIRECTION WHICH MOVES SOME WATER AWAY FROM LAND. OFFSHORE WINDS MOVE SURFACE WATERS AWAY FROM THE SHORE TOO, AND IN BOTH CASES THIS WATER IS REPLACED BY DEEP WATER.

23. Normal Trade Winds cause
Causes cold
tongue to
extend west
ALONG THE EASTERN EDGE OF THE PACIFIC OCEAN, OR IN OTHER WORDS THE WEST COAST OF THE AMERICAS, THE EFFECTS OF CORIOLIS AND OFFSHORE WINDS NORMALLY SUPPORT AN UPWELLING REGIME. THE UPWELLING OF DEEP COLD WATERS BRINGS DISOLVED NUTRIENTS (OR “FERTILIZERS”) SUCH AS NITRATES, PHOSPHATES AND SILICATES TO THE SURFACE. AT THE SURFACE THE SUNLIGHT AND NUTRIENTS REQUIRED FOR PHOTOSYNTHESIS COMBINE TO PROMOTE THE GROWTH PHYTOPLANKTON THAT FORMS THE BASE OF THE FOOD CHAIN. IT IS THE NUTRIENT FERTILIZERS BEING TRANSPORTED TO THE ILLUMINATED SURFACE AREA, KNOWN AS THE PHOTIC ZONE, THAT CREATES THE BEST CHEMICAL AND PHYSICAL ENVIRONMENT FOR PHOTOSYNTHESIS.
Deep, cold &
nutrient rich
waters
NORMAL CONDITIONS
SUPPORT COASTAL
UPWELLING.

24. RETURN THE FERTILIZING NUTRIENTS TO THE PHOTIC
SUNLIGHT
PHOTIC ZONE
ONLY UPWELLING CAN
RETURN THE FERTILIZING
NUTRIENTS TO THE PHOTIC
ZONE
THE ABUNDANCE OF PHYTOPLANKTON IN UPWELLING REGIONS PROVIDES FOOD FOR HERBIVOROUS ZOOPLANKTON. ZOOPLANKTON ARE IN TURN CONSUMED BY LARGER ZOOPLANKTON OR SMALL FISH SUCH AS ANCHOVIES AND SARDINES. LARGER FISH EAT SMALLER FISH AND CONSEQUENTLY UPWELLING REGIONS ALSO SUPPORT THE COMMERCIALLY IMPORTANT FISHERIES THAT FEED HUMANS.
NORMAL CONDITIONS
SUPPORT COASTAL
UPWELLING.

25. EL NINO SUPRESSES COASTAL UPWELLING, REDUCES NUTRIENTS
DURING EL NINO THE TROPICAL TRADE WINDS ARE SUPPRESSED AND THE MOVEMENT OF WATER OFFSHORE THAT PROMOTES COASTAL UPWELLING IS REDUCED. THE FLOW OF NUTRIENT FERTILIZER CHEMICALS UP TO THE SUNLIT SURFACE IS STOPPED. PHOTOSYNTHETIC ORGANISMS ARE AFFECTED, AND THE FOOD CHAIN COLLAPSES. THIS IMPACTS THE LOCAL FISHERIES AND HAS AN IMPACT ON BOTH THE FEEDING AND ECONOMY OF HUMAN POPULATIONS.
EL NINO SUPRESSES COASTAL
UPWELLING, REDUCES NUTRIENTS
& CAUSES SURFACE POPULATIONS
TO DISAPPEAR.

26. MEASURING AND PREDICTING
ENSO USING SATELLITE
DATA
2. TOPEX
/Poseidon
NOW LET’S LOOK AT HOW EARTH ORBITING SATELLITES PROVIDE DATA REGARDING ENSO, AND WE’LL STUDY SOME OF THE GREAT GLOBAL IMAGES THEY CAPTURE.

27. RADAR ALTIMETERY ABOARD THE TOPEX/POISEIDON, A JOINT FRENCH AND AMERICAN SATELLITE, MEASURES THE HEIGHT OF THE OCEAN SURFACE. REMEMBER WARM WATER EXPANDS AND ELEVATES THE SEA SURFACE, AND COLD WATER CONTRACTS AND DEPRESSES THE SEA SURFACE. THAT’S HOW TOPEX/POSEIDON GATHERS DATA REGARDING ENSO.

28. HERE’S AN OVERVIEW OF HOW THINGS OPERATE AS TOPEX/POSEIDON MEASURES SEA LEVEL AND SENDS THIS DATA BACK TO EARTH.

29. Birth of the
1997 El Nino
TOPEX/POSEIDON DATA IN GLOBAL VISUAL FORMAT SHOWING THE FORMATION OF THE BIG EL NINO EVENT IN NOTICE THE TONGUE OF VERY WARM WATER, MEASURED BY HIGHLY ELEVATED SEA LEVELS, ACROSS THE EASTERN EQUATORIAL PACIFIC.

30. TOPEX/POSEIDON DATA IN GLOBAL VISUAL FORMAT SHOWING THE MONTLY PROGRESSION OF THE 1997 EL NINO AND ITS DEMISE IN 1998.

31. El
Nino
TOPEX/POSEIDON DATA IN GLOBAL VISUAL FORMAT SHOWING THE FULLEST EXTENT OF THE 1997 EL NINO. THE TONGUE OF WARM WATER IS NOW MASSIVE AND HAS SPREAD UP THE COAST OF NORTH AMERICA AND INTO ALASKA. ~

32. THE SOUTHERN OSCILLATION IMPLIES PERIODIC WAVES OR EPISODES OF EL NINO AND LA NINA. HERE WE SEE TOPEX/POSEIDON DATA IN GLOBAL VISUAL FORMAT SHOWING THE OPPOSITE OF EL NINO AS THE 1998 LA NINA DEVELOPS. THIS DATA STREAM HAS BEEN SENT BY ANOTHER SATELLITE, JASON-1, ALSO A JOINT PROJECT BETWEEN FRANCE AND THE USA.

33. La
nina
BY JANUARY 2000 THE FULLEST EXTENT OF LA NINA CAN BE SEEN IN THIS IMAGE. ALL OF THE HOT WATER HAS NOW PILED UP ON THE FAR WESTERN SIDE OF THE PACIFIC AND COLDER THAN NORMAL WATER DOMINATES THE EASTERN PACIFIC (WEST COAST OF THE US AND THE EQUATOR). ~

34. HERE IS A 3-DIMENSIONAL OCEANIC VIEW OF EL NINO AND ITS ATMOSPHERIC CONVECTION PATTERNS.~
El Nino

35. HERE IS A 3-DIMENSIONAL OCEANIC VIEW OF LA NINA AND ITS ATMOSPHERIC CONVECTION PATTERNS.~
La Nina

36. A= normal cold water upwelling off Peru.
A GREAT 3-DIMENSIONAL VIEW OF A THE EARLY FORMATION OF EL NINO IN 1997. ~
Jan El Nino is coming !
A= normal cold water upwelling off Peru.
B= Kelvin wave of hot water moving to the East.

37. Sept. 1997 - El Nino conditions !
A GREAT 3-DIMENSIONAL VIEW OF A FULL EL NINO IN 1997. ~
Sept El Nino conditions !

38. A GREAT 3-DIMENSIONAL VIEW OF A THE EARLY FORMATION OF LA NINA IN 1998.~
May La Nina is coming !

39. Pacific to mid-Pacific.
(0-10S)(90W-80W)
Southern hemisphere:
Equatorial S. American
coast.
(5N-5S)(150W-90W)
Equator: mid-Pacific
to S. American coast.
(5N-5S)(160E-150W)
Equator: Australia to
mid-Pacific.
THE SOUTHERN OSCILLATION IS THE RYTHMIC ALTERATION BETWEEN EL NINO AND LA NINA CONDITIONS WITH “NORMAL” YEARS IN BETWEEN. HERE WE SEE STRIPS OF DATA TAKEN AT DIFFERENT LATITUDES ACROSS THE PACIFIC AND THE ELEVATED OR DEPRESSED SEA SURFACE OVER TIME.
(5N-5S)( W)
Equator: western
Pacific to mid-Pacific.

40. cold phase
1945
1946
1947
1948
1949
1954
1955
1956
1964
1967
1970
1971
1973
1975
1988
1999
neutral phase
1944
1950
1952
1953
1958
1959
1960
1961
1962
1966
1968
1974
1977
1978
1979
warm phase
1951
1957
1963
1965
1969
1972
1976
1982
1986
1987
1991
1997
1980
1981
1983
1984
1985
1989
1990
1992
1993
1994
1995
1996
THE SOUTHERN OSCILLATION, YEAR BY YEAR.

41. THE EFFECTS OF
EL NINO
NOW LET’S LOOK AT SOME OF THE EFFECTS OF EL NINO.

42. Normal Rainfall ~ El Nino Rainfall
EL NINO INCREASES RAINFALL IN CERTAIN REGIONS, BUT NOT OTHERS. ~
El Nino Rainfall

43. EL NINO EFFECTS ANNUAL TEMPERATURES
EL NINO EFFECTS ANNUAL TEMPERATURES. WINTER IN THE NORTHERN HEMISPHERE IS SHOWN HERE.

44. EL NINO EFFECTS ANNUAL TEMPERATURES
EL NINO EFFECTS ANNUAL TEMPERATURES. SUMMER IN THE NORTHERN HEMISPHERE IS SHOWN HERE.

45. EL NINO EFFECTS THE POSITION OF THE JET STREAM WHICH DIRECTS THE PATH OF INCOMING STORMS.

46. JET STREAM LOCATIONS DURING LA NINA.

47. TEMPERATURE VARIATIONS ACROSS THE LOWER 48 UNITED STATES DURING EL NINO.

48. RAINFALL VARIATIONS ACROSS THE LOWER 48 UNITED STATES DURING EL NINO.

49. Tree Ring
Growth
EVIDENCE OF THE SOUTHERN OSCILLATION IN THE PAST: GROWTH RINGS ARE LARGER WHEN IT IS WET.

50. EN EN Approximately 25% of the 23,000 pups born in June 1997
EL NINO EFFECTS THE FOOD CHAIN, AS SEEN IN THIS GRAPH OF THE SEA LION POPULATIONS OVER TIME.
Approximately 25% of the
23,000 pups born in June 1997
at San Miguel Island died.

51. EL NINO ALTERS THE MIGRATION OF SALMON IN THE PACIFIC NORTHWEST.

52. THE TOTAL YIELD OF PERUVIAN ANCHOVY, OR ANCHOVETA, SHOW RESPONSE TO THE SOUTHERN OSCILLATION.

53. Hurricane Pauline - 8 Aug 97
EL NINO’S WARM WATER CREATES FAVORABLE CONDITIONS FOR TROPICAL HURRICANE FORMATION.

54. PRECIPITATION IN LOS ANGELES FOLLOWS THE SOUTHERN OSCILLATION.

55. Number of Occurrences of Above Normal Rainfall
(out of 8 El Niño Seasons)
Sep.-Nov. Dec.-Feb. Mar.-Apr. Season
EUREKA
RED BLUFF
SACRAMENTO
SAN FRANCISCO
FRESNO
BAKERSFIELD
SANTA BARBARA
LOS ANGELES
SAN DIEGO
CALIFORNIA RAINFALL IN RESPONSE TO EL NINO SHOWN AT DIFFERENT LOCATIONS ACROSS THE STATE.

56. THE MONSTER RAIN THAT ENGLFED THE ENTIRE STATE OF CALIFORNIA AT THE END OF THE 1997-98 EL NINO.
3 Feb 98
GOES Infrared

57. February 1998 Record Rainfall Amounts (inches):
Location Total Former Record/Year
Ukiah in 1958
Santa Barbara *17.33 in 1962
UCLA *18.37 in 1918
Chatsworth *17.71 in 1962
Oxnard in 1962
Simi Valley *11.15 in 1992
Northridge *14.23 in 1962
Monterey in 1978
San Francisco in 1878
L.A. Cvc Ctr in 1884
L.A. Airport in 1962
Lompoc in 1918
Redwood City in 1986
Santa Maria in 1962
Long Beach in 1937
* Denotes an all-time-record February monthly total.
RECORD BREAKING EL NINO TOTAL RAINFALL SUMMARIES AT DIFFERENT LOCATIONS IN CALIFORNIA.

58. EL NINO’S EFFECT ON HUMOR.

59. T H E E N D
THANKS FOR USING MY ENSO POWERPOINT SHOW!

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