Philippine Journal of Science
139 (1): 119-126, June 2010
ISSN 0031 - 7683
Short Communication
The 2009-2010 El Niño Southern Oscillation in the
Context of Climate Uncertainty: The Philippine Setting
Graciano P. Yumul Jr.1,2, Carla B. Dimalanta1, Nathaniel T. Servando3,
and Flaviana D. Hilario3
1
National Institute of Geological Sciences, College of Science,
University of the Philippines, Diliman, Quezon City, Philippines
2
Department of Science and Technology, Bicutan, Taguig City, Metro Manila, Philippines
3
Philippine Atmospheric, Geophysical, and Astronomical Services Administration,
Department of Science and Technology, Science Garden, Diliman, Quezon City, Philippines
The Philippines is no stranger to El Niño Southern Oscillation (ENSO) events and its attendant
impacts. Despite being plagued by several disastrous weather events that brought in a lot of
rains during the period of September – October 2009, the country had, in fact, been warned
of a conventional El Niño event as early as August 2009. With the continued below normal
rainfall conditions due to the moderate 09-10 El Niño event being experienced in the country,
measures to prepare against these drought conditions are being implemented. The drought
and dry spell conditions are expected to persist until summer so the country must switch to a
crisis mode in dealing with the impacts that will accompany this ENSO event.
Key Words: climate change, drought, El Niño Southern Oscillation, Philippines
INTRODUCTION
The El Niño Southern Oscillation (ENSO) events in
the Philippines are characterized generally by drought
conditions (e.g. Changnon 1999; Lyon et al. 2006;
Abastillas 2009). This would happen if the ENSO is a
conventional one when warming occurs in the eastern
Pacific Ocean near the South American region. Recent
works have recognized a different kind of El Niño, the
Modoki or Dateline El Niño, which forms in the central
Pacific region near the International Deadline (e.g. Ashok
et al. 2007; Weng et al. 2009). Should Dateline El Niño
occur, the effects on the Philippines would actually be
the reverse. This means that instead of expecting drought,
Dateline El Niño would result in extensive rainfall in the
country similar to what has been observed in other places
(e.g. Pielke and Landsea 1999; Larkin and Harrison 2005a;
Kao & Yu, 2009). This happened in 2004, a Dateline
*Corresponding author: [email protected]
[email protected]
El Niño year, wherein the eastern Luzon seaboard,
specifically the province of Quezon and its vicinity,
received anomalous amounts of rain that resulted in loss
of lives and destruction of properties (Yumul et al. 2009a).
In dealing with conventional El Niño events, available
data shows that the Philippines had learned and had
improved much in the handling these kind of occurrences.
Significant improvement has been observed on how
the Government handled past El Niño events in terms
of proactive trade policy, local distribution and pricing
of rice coupled with improved world rice market and
available foreign exchange reserves (Chang and Reuveny
2009; Dawe et al. 2009). This is further complemented by
increased understanding of the ENSO phenomenon and
available advance technology that gives early warning
about this climate event (Dawe et al. 2009; Yumul et al.
2009b). Sea surface temperature anomaly (SSTA) has
been known to directly affect rice production. As the SSTA
increases and drought ensues, rice production decreases.
119
Philippine Journal of Science
Vol. 139 No. 1, June 2010
This has occurred not only in the Philippines but also in
other Asian countries like Indonesia and Thailand (e.g.
Naylor et al. 2001; Dawe et al. 2009; delos Reyes and
David 2009). In spite of these realizations and the lessons
we have learned in handling this kind of event, the country
cannot afford not to be alarmed whenever the prevailing
condition is that of an El Niño.
In 2009, the Philippines was characterized by hazards
and disasters that were mostly triggered by too much
water – from floods and flash floods to landslides. What
is ironic is that most of the media releases at the start
of this year were warnings and reminders to observe
water conservation because of the ENSO event being
experienced in the country. The present ENSO event has
been recognized last year that resulted into the Philippine
Government issuing an advisory about the 2009-2010 El
Niño as early as August 2009. The public, though, may not
have really felt the need to prepare for El Niño because
the period of September-October 2009 during the initial
phase of the El Niño was actually very wet due to tropical
cyclones characterized by too much water content dumped
in Luzon. It is the purpose of this paper to characterize
the 2009-2010 El Niño event especially in the context of
climate change and how the Philippines can mitigate the
negative impacts of this ENSO event.
2009-2010 ENSO
The upper ocean in the tropical eastern Pacific from time
to time undergoes extensive warming which may last up
to three months or more. This unusual warming, known
as El Niño, is attributed to a change in atmospheric
pressure between the western and central regions of the
Pacific Ocean. El Niño causes tropical rainfall to shift
from the western to the eastern Pacific Ocean bringing
increased rains in Ecuador and northern Peru and drought
to Indonesia and Australia (WMO 2009). The observed
ocean and atmospheric changes are part of the global
variations in the atmosphere referred to as the El Niño
Southern Oscillation (ENSO). The Southern Oscillation
pertains to changes in sea level air pressure patterns in the
Southern Pacific Ocean. A relationship has been observed
in the change in air pressures between Darwin, Australia
and Papeete, Tahiti in the South Pacific. The average air
pressure in Darwin is higher than in Tahiti during an El
Niño. The daily pressure variations between Tahiti and
Darwin are computed as the Southern Oscillation Index
and offer a means of monitoring ENSO conditions (e.g.
Moya and Malayang 2004; National Weather Service
2009).
El Niño and La Niña events are monitored using sea
surface temperature (SST) anomalies which has resulted
in the subdivision of the tropical Pacific basin into four
regions based on their SSTs: Niño 1 (80°-90°W and 5°120
Yumul et al.: 2009-2010 El Niño Southern
Oscillation in the Philippines
10°S), Niño 2 (80°-90°W and 0°-5°S), Niño 3 (90°-150°W
and 5°N-5°S) and Niño 4 (150°-160°E and 5°N-5°S).
With the increasing number of studies on the ENSO, some
modifications have been proposed for these regions. Niño
1+2 combines the original Niño 1 and Niño 2 while Niño
3.4 has been proposed to cover the region between 120°150°W and 5°N-5°S. An El Niño event is declared if the
SST anomaly in the Niño 3.4 region (deviation from the
normal) is at least 0.5°C over a period of three consecutive
months (e.g. Trenberth 1997; Moya and Malayang 2004;
Kao and Yu 2009). Based on deviations of the SSTs from
normal, El Niño events can be classified as weak (SSTA =
0.5 to 1.0°C), moderate (SSTA = 1.0 to 1.5°C) and strong
(SSTA >1.5°C) (e.g. NOAA 2009). The 1982-1983 and
1997-1998 are considered strong events while the 19941995 El Niño event is weak and the 1986-1987, 1991-1992
and 2002-2003 events are considered moderate ones (e.g.
Landsea and Knaff 2000; McPhaden 2004). In addition to
the decreased amount of rainfall in general in the Western
Pacific region, the duration of a conventional El Niño
event is also used to gauge its severity. For the present
El Niño, the peak SSTA was at 1.8°C but was noted only
for a short duration. The overall average SSTA which
persisted for a long period is 1.5°C making the 2009-2010
El Niño a moderate event.
In June 2009, a steady increase in SSTs was reported
by various meteorological agencies and SST anomalies
ranged from 0.6°C to 0.9°C. By July 2009, SST values
were 1°C above average along the equatorial eastern
Pacific marking the arrival of El Niño. The 2009-2010
El Niño is, thus, considered a conventional El Niño
since the maximum SST anomalies are in the tropical
eastern Pacific. This is in contrast to the Modoki or
Dateline El Niño which, as noted above, is characterized
by maximum SST anomalies which converge near the
dateline (e.g. Weng et al. 2007; Kao and Yu 2009). Most
model forecasts indicated that the El Niño will persist for
several months with NOAA predicting that the condition
was going to continue until winter of 2009-2010. The El
Niño gained strength in December 2009 with calculated
Niño-3.4 index values greater than +1.8°C. The advisories
warned of possible increased precipitation in the central
and west-central Pacific Ocean whereas drier than average
conditions were expected to prevail over Indonesia
(Climate Prediction Center 2009; 2010; NOAA 2009).
In the Philippines, the Department of Science and
Technology - Philippine Atmospheric, Geophysical
and Astronomical Services Administration (DOSTPAGASA) also started issuing warnings and advisories
on the impending El Niño condition that was likely to
impact the country. Climate models suggest that the
country may experience the effects of El Niño until June
2010. Effects such as below normal rainfall conditions
are already experienced in some parts of the country
Philippine Journal of Science
Vol. 139 No. 1, June 2010
(Figure 1). This is especially critical for the Visayas and
Mindanao areas which, despite the enormous amounts
of rain dumped in Luzon by the September – October
2009 weather disturbances, received minimal rainfall
since that period. Some areas in Capiz Province in
Panay island that have been experiencing below normal
rainfall since August, were declared to be under drought
conditions (five consecutive months of below normal
rainfall) (Figure 1). By December 2009, dry spell (three
to four consecutive months of below normal rainfall) was
affecting other parts of the country such as Pampanga,
Batangas, Aurora and Quezon in Luzon island; Northern
Samar, Aklan, and Guimaras in the Visayas; and Davao
del Sur, South Cotabato and Sultan Kudarat in Mindanao
(DOST-PAGASA 2010). The impacts of the 2009-2010
El Niño event in the Philippines worsened by February
2010. The DOST-PAGASA El Niño Advisory No. 7
reported that three more provinces, namely, Isabela, Nueva
Yumul et al.: 2009-2010 El Niño Southern
Oscillation in the Philippines
Viscaya and Quirino were under drought conditions.
The number of provinces under dry spell also increased.
These include Abra, Benguet, Kalinga, Ifugao, Apayao,
Mountain Province, Ilocos Norte, Ilocos Sur, La Union,
Pangasinan, Cagayan and Bataan. The National Disaster
Coordinating Council reported that the crop damage due
to the current El Niño is estimated at P10.4 billion with
the Cagayan Valley incurring the biggest loss.
DISCUSSION
From wet to dry: Turning off the faucet
When Government announced in August 2009 that the
country must prepare for an El Niño based on DOSTPAGASA prognosis, it was not surprising that people
were not so impressed considering what happened in
Figure 1. Rainfall anomaly maps for the Philippines for the months of August 2009 to January 2010. Since August 2009, some areas in
Capiz have received below normal rainfall (yellow and red colored areas). Other parts of Luzon and Visayas are under dry spell
conditions as of January 2010 (source: DOST-PAGASA).
121
Philippine Journal of Science
Vol. 139 No. 1, June 2010
September to October 2009. As is known now, September
saw the onslaught of Tropical Storm Ketsana (local name:
Ondoy) that brought Metropolitan Manila and nearby
areas to a standstill due to massive flooding. October saw
the flooding of Northern Luzon, specifically Pangasinan
while Benguet experienced a number of rainfall-induced
landslides, due to Typhoon Parma (local name:Pepeng).
The latter part of October saw the flooding of southern
Luzon due to Typhoon Mirinae (local name: Santi). The
media started asking how it can be so wet when the
Philippines should actually be under an El Niño event.
Nonetheless, by November 2009, it was recognized that
although Luzon was very wet, Visayas and Mindanao
were under stress in terms of water scarcity (Figure
1). In December 2009, most of Luzon had received
below normal rainfall resulting in some provinces being
recognized under or about to experience dry spell and
drought conditions. An area is considered under a dry
spell condition if its rainfall has been below normal for at
least three months while areas under drought conditions
are those that have received below normal rainfall for
five months.
Available data shows that as of January 2010, the
amount of rain was still below normal in most parts of
the country triggering the reactivation of the Department
of Agriculture-led Task Force El Niño to deal with the
situation (Figure 1). The National Disaster Coordinating
Council (NDCC) coordinates other efforts to ensure
that the negative impact of this event is minimized. The
APEC Climate Center (2010) climate forecast shows
that the 2009-2010 El Niño event continues to prevail
in the Pacific Ocean with warm sea surface temperature
anomalies exceeding 1.5°C. Available data suggests
that the El Niño is now near its peak and is expected
to persist through spring (APEC Climate Center 2009).
The APCC climate outlook for February to April 2010
indicates warm conditions and below normal rainfall
for the Philippines (Figure 2). As is always the case,
when water scarcity leading to drought is just starting
(meteorological drought), the concern is more on the
natural event that caused it. But as the drought progresses
to agricultural and hydrological droughts, the issue
shifts to how the negative impacts (social, economic and
political) of the drought on society can be minimized
(WMO 2006). For urban centers in the country, repairs
of leaks and reduction of water pressure are being done
with the possibility of rationing water. Increasing public
awareness on the impending problem and convincing
everybody to conserve water are being done now. Shallow
tube wells, introduction of drought resistant rice variety,
planting quick turn-around plant varieties in areas with
enough moisture and repair of irrigation systems are being
implemented in the agricultural rural areas. With the
shutdown or reduced operation of hydroelectric plants,
122
Yumul et al.: 2009-2010 El Niño Southern
Oscillation in the Philippines
the maintenance of fuel-fired power plants is being fast
tracked to avoid a power crisis. For that matter, specific
and directed interventions by the local government units
during this particular El Niño event must be the norm as
the effects of ENSO vary regionally.
It is supposed to be dry but why is there flooding?
While the NDCC is preparing for the negative effects
of the El Niño event, floods and landslides were being
reported along the eastern seaboard of Luzon (i.e. Aurora)
and Mindanao (i.e. Surigao-Davao area) due to rains
associated with the Northeast Monsoon and tail-end of the
cold front. For that matter, Naujan in Oriental Mindoro
was also declared under a state of calamity in the second
week of January 2010 due to strong rains. It is important
for people to understand that: a) if there is an El Niño
event, not all areas in a country would be dry. Some
would still be receiving rain even to the point of causing
flooding as observed in the mentioned areas; and b) there
are no two similar El Niño events (e.g. McPhaden 2004).
Although we have learned a lot from previous El Niño
events, we cannot assume or even conclude that what were
true then can be applicable today.
It is in this context that the present 2009-2010 El Niño
event must not be taken as an individual event but as part
of the whole climate process. If one were to look at the
2009 weather, it was characterized by very wet conditions
(e.g. anomalous rain associated with the cold front in
January 2009, very wet summer covering the months
March to May 2009 and the strong tropical cyclones
that hit the country) and can be said to be La Niña-like
(Figure 1). Conventional La Niña events in the country
are generally wet. This has been explained by the presence
and greater chances of formation of vertical shear winds
during La Niña events which is not present during El
Niño events (e.g. Pielke and Landsea 1999; Chan and
Liu 2004). Thus, the 2009 events are consistent with
the empirical observation that in the Philippines, wet
conditions precede an El Niño event. Additional studies
are needed to constrain and interpret these observations
in the general context of a globally warming world within
the backdrop of climate uncertainty (e.g. McPhaden 2004;
Larkin and Harrison 2005b; Tootle et al. 2009).
Although the El Niño phenomenon cannot be said
to directly indicate any changes in the climate, any
perturbations in the El Niño cycle can actually be
interpreted as a possible representation of climate
uncertainty (Diaz et al. 2001; IPCC 2007). For that matter,
in the context of human-induced global warming, climate
uncertainty is more of the norm rather than the exception
(e.g. Parry et al. 2001; Kerr 2007; Roe and Baker 2007;
Risbey 2008). In the Philippines, conventional El Niño
events are associated with droughts. With the added effect
Philippine Journal of Science
Vol. 139 No. 1, June 2010
Yumul et al.: 2009-2010 El Niño Southern
Oscillation in the Philippines
Figure 2. The probabilistic multi model ensemble (MME) forecasts for the period February to April 2010. The MME model
indicates that the Philippines will continue to experience: A. below normal rainfall (50 to 70%) and B. temperatures
will remain warmer (source: APEC Climate Center 2010).
123
Philippine Journal of Science
Vol. 139 No. 1, June 2010
Yumul et al.: 2009-2010 El Niño Southern
Oscillation in the Philippines
Table 1. Data for the different dams in Luzon island, as of February 9, 2010, show lower water levels compared to
the normal elevations (source: DOST-PAGASA).
Reservoir
Water Level
(m)
Normal High/
Spilling
Elevation (m)
Deviation from
Normal High
Elevation (m)
Elevation
From Rule
Curve (m)
Deviation from
Rule Curve (m)
ANGAT
198.86
212.00
-13.14
201.26
12.40
IPO
100.76
100.87
-0.11
-
-
LAMESA
79.93
80.00
-0.07
-
-
AMBUKLAO
740.26
752.00
-11.74
752.00
-11.74
BINGA
561.30
575.00
-13.70
574.00
-12.70
SAN ROQUE
255.71
278.00
-22.29
256.79
-1.08
PANTABANGAN
207.34
221.00
-13.66
210.31
-2.97
MAGAT
166.93
193.00
-26.07
187.51
-20.58
Dams
of global warming and climate uncertainty, El Niñoinduced droughts can actually be expected to be more
severe (Parry et al. 2009; Schneider 2009; Smith et al.
2009; Stine et al. 2009).
Shall we go on a crisis-mode?
The different institutions in the country, from the
Government (both national and local) to the academe,
private sector and civil society organizations, are all
advocating to proactively address the negative effects
of El Niño. There is a good reason for this. The data
would show that there are provinces that are under
dry spell/ drought level conditions. For Metropolitan
Manila, the water inflow to the Angat Dam, which is
its main water source, is on the low side (Table 1).
Reduced water pressure, intensive leak repairs, standby
well reactivation and installation of static tanks, among
others, are being done by the water concessionaires to
ensure that Metropolitan Manila will have water supply
until June 2010 (http://business.inquirer.net/money/
breakingnews/view/20100114-247386/MWSS-to-drawless-water-from-Angat-dam-by-February; http://www.
mayniladwater.com.ph/news.php). The National Water
Resources Board (NWRB) and the water concessionaires
have identified additional sources of water that can be
tapped should the need arise. By law, it is also set that
water supply for domestic usage takes precedence over
that of power generation and irrigation. However, if
the drought condition continues past July, the capital
city may have a problem with water supply. It would
be remembered that the 2007 dry spell occurred in
July and August 2007 (Yumul et al. 2009a; 2009b). It
is only February (as of the initial writing of this short
communication) and the summer months are just about
to start. That would mean that the chances of rainfall
would be very low. Mindanao, for that matter, has been
124
placed under a state of calamity in March 2010 due to
serious power outages since a significant amount of their
power supply comes from hydroelectric power plants.
With the absence of rain, these hydroelectric plants will
have low water level, preventing them to optimize their
power generating capacities. With this kind of scenario,
the country really has to tackle things proactively. There
should already be a shift in the “reason for concern”
status to that of “crisis” mode. It is in having this crisis
mode status that people start to take notice of what is
happening and start doing things expected from them.
This is, however, easier said than done. Each decision
involves socio-economic implications. It is in this
respect, that the different stakeholders have to fully
understand the issue and determine which options they
would adopt. By doing this, it is expected that most,
if not all, will be onboard in addressing the negative
impacts of the 2009-2010 ENSO event.
CONCLUSION
Available data shows that the 2009-2010 conventional
El Niño is a moderate one and that it may last until June
2010. However, one cannot dismiss the possibility that the
lack in water that we are experiencing in February will
not extend until the third quarter of this year. Instead of
taking the risk that we can run out of water by July 2010,
it may be prudent for the country to go on crisis mode and
assume that the prevailing El Niño event can extend even
after the summer (April, May, June) of 2010.
Philippine Journal of Science
Vol. 139 No. 1, June 2010
ACKNOWLEDGEMENT
Discussions with the different members of the National
Disaster Coordinating Council, especially the Office of
Civil Defense-Department of National Defense, have
provided us a good glimpse of the preparations our country
is doing. To these people we are thankful. Logistic support
came from the Department of Science and Technology,
Philippine Atmospheric, Geophysical and Astronomical
Services Administration and University of the PhilippinesNational Institute of Geological Sciences.
REFERENCES
ABASTILLAS RG. 2009. Overview on climate and
trends in the Philippines. Unpublished DOST-PAGASA
report.
[APCC] APEC CLIMATE CENTER. 2009. Seasonal
climate outlook for OND 2009 and climate highlights
for July – September 2009. APCC Newsletter 4:3-4.
[APCC] APEC CLIMATE CENTER. 2010. Climate
outlook for February – April 2010. Accessed from
http://www.apcc21.net/climate/climate01_01.php. on
08 February 2010.
ASHOK K, BEHERA SK, RAO SA, WENG H,
YAMAGATA T. 2007. El Niño Modoki and its
possible teleconnection. J Geophys Res 112: C11007,
doi:10.1029/2006JC003798.
CHAN JCL, LIU KS. 2004. Global warming and western
North Pacific typhoon activity from an observational
perspective. J Climate 17:4590-4602.
CHANG H-O, REUVENY R. 2009. Climatic natural
disasters, political risk, and the international trade. Global
Envl Change doi:10.1016/j.gloenvcha.2009.11.005.
CHANGNON SA. 1999. Impacts of 1997-1998 El Niñogenerated weather in the United States. Bull Amer
Meteor Soc 80, 1819-1828.
[CPC] CLIMATE PREDICTION CENTER. 2009.
El Niño/Southern Oscillation (ENSO) Diagnostic
Discussion – 9 July 2009. Accessed from http://
www.cpc.noaa.gov/products/ analysis_ monitoring/
enso_disc_jun2009/ on 28 January 2010.
[CPC] CLIMATE PREDICTION CENTER. 2010.
El Niño/Southern Oscillation (ENSO) Diagnostic
Discussion – 7 January 2010. Accessed from http://
www.cpc.noaa.gov/products/ analysis_monitoring/
enso_disc_jan2010/. on 28 January 2010.
DAWE D, MOYA P, VALENCIA S. 2009. Institutional,
Yumul et al.: 2009-2010 El Niño Southern
Oscillation in the Philippines
policy and farmer responses to drought: El Niño events
and rice in the Philippines. Disasters 33: 291-307.
DIAZ HF, HOERLING MP, EISHEID JK. 2001. ENSO
variability, teleconnections and climate change. Intl J
Climatol 21: 1845-1862.
DELOS REYES MLF, DAVID WP. 2009. The effect of
El Niño on rice production in the Philippines. Philip
Agric Sci 92: 170-185.
[DOST-PAGASA] DEPARTMENT OF SCIENCE AND
TECHNOLOGY - PHILIPPINE ATMOSPHERIC,
GEOPHYSICALAND ASTRONOMICAL SERVICES
ADMINISTRATION. 2010. El Niño advisory No. 5.
Accessed from http://kidlat.pagasa.dost.gov.ph/cab/
ensoadvi.htm. on 28 January 2010.
[IPCC] INTERGOVERNMENT PANEL ON CLIMATE
CHANGE. 2007. Climate Change 2007: The Physical
Basis. Cambridge, United Kingdom and New York,
NY, USA: Cambridge University Press. 996 p.
KAO H-Y, YU J-Y. 2009. Contrasting Eastern-Pacific and
Central-Pacific Types of ENSO. J Climate 22: 615-632.
KERR R. 2007. Pushing the scary side of global warming.
Science 316: 1412-1415.
LANDSEA CW, KNAFF JA. 2000. How much skill was
there in forecasting the very strong 1997-1998 El Niño?
Bull Amer Meteor Soc 81, 2107-2120.
LARKIN NK, HARRISON DE. 2005a. On the definition
of El Niño and associated seasonal average U.S.
weather anomalies. Geophys. Res Lett 32, L13705,
doi:10.1029/2005GL022738.
LARKIN NK, HARRISON DE. 2005b. Global seasonal
temperature and precipitation anomalies during El Niño
autumn and winter. Geophys. Res Lett 32, L16705,
doi:10.1029/2005GL022860.
LYON B, CRISTI H, VERCELES ER, HILARIO FD,
ABASTILLAS R. 2006. Seasonal reversal of the
ENSO rainfall signal in the Philippines. Geophys Res
Letters 33: L24710, doi:10.1029/2006GL028182.
McPHADEN MJ. 2004. Evolution of the 2002/03 El Niño.
Bull Amer Meteor Soc doi:10.1175/BAMS-85-5-677.
MOYA TB, MALAYANG BSIII. 2004. Climate variability
and deforestation – reforestation dynamics in the
Philippines. Environ Development and Sustainability
6: 261–277.
NATIONAL WEATHER SERVICE. 2009. El Nino
Southern Oscillation (ENSO). Accessed from http://
www.srh.noaa.gov/srh/jetstream/tropics/enso.htm. on
23 August 2009.
125
Philippine Journal of Science
Vol. 139 No. 1, June 2010
[NOAA] NATIONAL OCEANIC AND ATMOSPHERIC
ADMINISTRATION. 2006. ENSO cycle: recent
evolution, current status, and predictions. Climate
Prediction Center, National Centers for Environmental
Prediction. Accessed from http://www.cpc.ncep. noaa.gov/
products/ analysis_monitoring/lanina/ on 04 April 2010.
[NOAA] NATIONAL OCEANIC AND ATMOSPHERIC
ADMINISTRATION. 2009. El Niño arrives; expected
to persist through winter 2009-10. Accessed from http://
www.noaanews.noaa.gov/stories2009/20090709_
elnino.html. on 28 January 2010.
NAYLOR RI, FALCON WP, ROCHBERG D, WADA,
N. 2001. Using El Niño/Southern Oscillation climate
data to predict rice production in Indonesia. Climatic
Change 50: 255-265.
PARRY M, LOWE J, HANSON C. 2009. Overshoot,
adapt and recover. Nature 458: 1102-1103.
PARRY M, ARNELL N, MCMICHAEL T, NICHOLLS
R, MARTENS P, KOVATS S, LIVERMORE M,
ROSENZWEIG C, IGLESIAS A, FISCHER G. 2001.
Millions at risk: defining critical climate change threats
and targets. Global Environ Change 11: 181-183.
Yumul et al.: 2009-2010 El Niño Southern
Oscillation in the Philippines
rim during recent El Niño Modoki and El Niño events.
Clim Dyn 32: 663-674.
[WMO] WORLD METEOROLOGICAL
ORGANIZATION. 2006. Drought Monitoring
and Early Warning: Concepts, Progress and Future
Challenges. WMO Publication No. 2006, Geneva,
Switzerland: World Meteorological Organization. 24p.
[WMO] WORLD METEOROLOGICAL
ORGANIZATION. 2009. El Niño. Accessed from
http://www.wmo.int/pages/about/wmo50/e/world/
climate_pages/el_nino_e.html. on 23 August 2009.
YUMUL GPJR, CRUZ NA, SERVANDO NT,
DIMALANTA CB. 2009a. The last five years (20042008) of extreme weather events and related disasters
in the Philippines: a foreboding of what climate change
will bring? Disasters, In press.
YUMUL GPJR, CRUZ NA, DIMALANTA CB,
HILARIO FD, SERVANDO NT. 2009b. The 2007
dry spell in Luzon (Philippines): Its cause, impact
and corresponding response measures. Clim Change
doi:10.1007/s10584-009-9677-0.
PIELKE RAJR, LANDSEA CW. 1999. La Niña, El Niño
and Atlantic Hurricane Damages in the United States.
Bull Amer Meteor Soc 80: 2027-2033.
http://business.inquirer.net/money/breakingnews/
view/20100114-247386/MWSS-to-draw-less-waterfrom-Angat-dam-by-February (Accessed on April
24, 2010)
RISBEY J. 2008. The new climate discourse: Alarmist or
alarming? Global Environ Change 18: 26-37.
http://www.mayniladwater.com.ph/news.php (Accessed
on April 24, 2010)
ROE G, BAKER M. 2007. Why is climate sensitivity so
unpredictable? Science 318: 629-632.
SCHNEIDER S. 2009. The worst-case scenario. Nature
458: 1104-1105.
SMITH J, SCHNEIDER S, OPPENHEIMER M, YOHE
GW ET AL. 2009. Assessing dangerous climate change
through an update of the Intergovernmental Panel on
Climate Change (IPCC) “reasons for concern”. Proc
Nat Acad Sci U.S.A. 106: 4133-4137.
STINE A, HUYBERS P, FUNG I. 2009. Changes in
the phase of the annual cycle of surface temperature.
Nature 457: 435-441.
TOOTLE GA, PIECHOTA TC, AZIZ O, MILLER WP,
LAKSHMI V, DRACUP JA, JERLA C. 2009. The
2009-2010 El Niño: Hydrologic relief to U.S. regions?
EOS Trans Am 90, 481-482.
TRENBERTH KE. 1997. The definition of El Niño. Bull
Am Meteorol Soc 78: 2771-2777.
WENG H, BEHERA SK, YAMAGATA T. 2009.
Anomalous winter climate conditions in the Pacific
126