Credits- Ma'am Lea

1. Climatic Changes

2. ENSO
• develops in the Pacific Ocean,
• associated with extreme climatic
variability; devastating rains, winds,
drought,
• migration, from time to time, of warm
surface waters from the western equatorial
Pacific Basin to the eastern equatorial
Pacific region, along the coasts of Peru
and Ecuador.

3. Origin
• Boy Child; Little One
• Anchovy Peruvian Fishermen; warm
currents flowing along American Coasts
during Christmas

4. Occurence
• Under normal conditions, the prevailing
southeasterly trade winds produce a
surface current flowing toward the equator
along the western South American coast.
The waters leaving the coast are replace
by colder waters from below (upwelling),
which is rich in phytoplankton, the food
source of anchovy.

5. More….
• The warm current (El Niño) temporarily
displaces nutrient-rich upwelling cold
water resulting in the heavy harvest of
anchovies. The abundant catch, however,
is shortlived. What follows is a sharp
decline in the fish population , resulting in
a lesser catch. At times, warming is
exceptionally strong and ruins the anchovy
harvest.

6. Characteristics
•
It occurs in the Pacific basin every 2 to 9 years;
•
- It usually starts during the Northern winter (December to
February);
•
- Once established, it lasts until the first half of the following year,
although at times, it stays longer;
•
- It exhibits phase-locking in annual cycles (El Niño and rainfall
•
- fluctuations associated with it tend to recur at the same time of the
year; and
•
- It usually has a biennial cycle (El Niño events will often be
preceded
and/or followed by La Niña).

7. Indicators
• Abnormalities such as:
- delayed onset of the rainy season
- early termination of the rainy season
- weak monsoon activity
*isolated heavy downpours with short duration
- weak tropical cyclone activity
*far tropical cyclone track
*less no. of tropical cyclones entering the PAR
*less intense tropical cyclones

8. Effects
• environmental (degradation of soil which could
lead to desert-like conditions if persistent, effect
on water quality like salt water intrusion, high
forest/grass/bus fire risk, domestic water supply
shortages, etc.);
• (b) social (disruption of normal human activities,
migration to urban communities, human and
health problems, etc.); and
• (c) economic (unemployment, food shortages,
significant reduction in the productivity and
subsequent revenue of various industries,
hydro-electric power generation, etc.).

9. La Nina
– La Niña develops over the central and eastern
equatorial Pacific and is characterized by
unusually cold surface temperatures of the
ocean. La Niña is associated with extreme
climatic variability such as devastating rains,
winds, drought

10. Origin
• The term La Niña (the Little Girl) was used
by many scientists and meteorologists to
differentiate it from El Niño. It is
sometimes called El Viejo (Old Man), AntiEl Niño, or simply "cold event" or "cold
episode".

11. Impact
• Impacts of La Niña on Philippine climate include
anomalies in rainfall, temperature and tropical
cyclone activities. During La Niña conditions,
major parts of the country experience near
normal to above normal rainfall conditions
particularly over the eastern sections of the
country. La Niña conditions also favor tropical
cyclone formation over the western Pacific which
tend to increase the number of tropical cyclones.

12. Reference
• http://kidlat.pagasa.dost.gov.ph/cab/enso.htm