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Mercedes Gomez Jacobo
Faculty Mentor: Dr. Justin Schoof
07/25/12
El Niño Southern Oscillation (ENSO) impacts in Central America-El Salvador
Abstract
Central America (C.A.) is home to many biodiversity hot spots and over 50 million
people. This study will take an in depth look at El Salvador temperature and precipitation records
during different phases of El Niño-Southern Oscillation(ENSO). The first goal is to review the
available literature on drivers of climate variability in El Salvador, including topographic
features and ocean/atmosphere interactions. The second goal is to investigate the potential role of
climate change in El Salvador, and its implications for humans/biodiversity with repeated events
such as floods, landslides and drought. The third goal of this study is to analyze available data
and quantify the effects of ENSO on climate in El Salvador. The study includes a review and
comparison of two climate model predictions for Central America. The results of this research
confirm that ENSO has an effect on the regional climate of El Salvador. Some of the results were
consistent with past studies, such as increased surface air temperatures during El Niño, while
others were counter to past studies, such as precipitation during La Niña. El Salvador receives
less rain during ENSO periods than during neutral years. Better climate observation and
improved modeling will assist in mitigating disasters in the future.
1. Introduction
The climatology of Central America is the result of complex interactions between the
surrounding oceans and natural cyclical events. It is important to understand because it is home
to over 17,000 plant species and many biodiversity hotspots (Dow and Downing, 2006). The
Central American isthmus and the Caribbean Islands are home to over 50 million people
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(Karnauskas and Busalacchi, 2008). The purpose of this study is to review available literature on
climate in Central America with an emphasis on El Salvador, investigate the potential role of
climate change in the area, and use the available data to quantify the effects of El Niño-Southern
Oscillation (ENSO) in El Salvador. Central America, as defined by the United Nations geo
scheme, includes the following countries: Belize, Mexico, Guatemala, Honduras, El Salvador,
Nicaragua, Costa Rica and Panama (www.unstats.un.org). Within Central America, El Salvador
is a part of the Pacific ring of fire and is home to over 20 volcanoes (Hall and Brignoli, 2003),
which further contribute to topographic and climatological variations.
The climate of El Salvador is influenced by sea surface temperatures (SSTs) (Ose and
Arakawa, 2011), northeast trade winds (Hall and Brignoli, 2003), and the Intertropical
Convergence Zone (ITCZ) (Haggerty, 1988). The mountainous regions within the country such
as the Sierra Madre de Chiapas and Cordillera Alotepeque-Metapan also have influence over the
regional climate. The combination of high relief and abundant moisture availability creates
ecosystems with high biodiversity, which are particularly sensitive to changing climate and El
Niño – Southern Oscillation (ENSO) (Karmalkar et al., 2011).
Relatively little research has focused specifically on the climate of Central America and
the impacts of ENSO, even less exists on the direct regional impact on El Salvador (Hernandez
et al., 2006). This region has experienced negative environmental impacts in the last 50 years due
to climate change (Flannery, 2005), deforestation (Hernandez et al., 2006), and major climatic
events such as hurricanes (Emanuel, 2005). The United Nations and the World Health
Organization (WHO) have found that some of the most devastating climatic events are
associated with ENSO, such as hurricane Stan which severely affected El Salvador in 2005 in the
form of lingering torrential rain (Verner, 2010).
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Figure 1.Political map of Central America showing the location of El Salvador along the Pacific
Coast (source: www.lonelyplanet.com)
Figure 2.Map of El Salvador showing departments (source: www.geology.com)
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1.1. ENSO
El Niño Southern Oscillation is a natural phenomenon that occurs every 3 to 7 years and
is reflected in SSTs in the equatorial Pacific Ocean. El Niño is characterized by unusually warm
SSTs and La Niña is characterized by unusually cool SSTs. For ENSO monitoring, the National
Oceanic and Atmospheric Administration (NOAA) uses SSTs in the Niño 3.4 region (120W to
170W longitude and 5S to 5N latitude). El Niño, also known as the warm phase, occurs when
the 3-month mean SST anomaly in the Niño 3.4 region exceeds +0.5oC. La Niña, also known as
the cold phase, occurs when the 3-month mean SST anomaly in the Niño 3.4 region exceeds 0.5oC. When the SSTs are not consistent with El Niño or La Niña, conditions are said to be
neutral (www.cpc.ncep.noaa.gov).
ENSO has a near simultaneous effect on Central American temperature and precipitation
(Karmalkar, 2011). In general during the warm phase of ENSO (El Niño) positive surface air
temperature anomalies and negative precipitation anomalies are observed over Central America.
Respectively during the cold phase of ENSO (La Niña) negative surface air temperatures are
recorded and positive precipitation anomalies are observed over the same region (Nagura et al.,
2007).
1.2. Human impact
El Salvador is the most densely populated country in the region with over 6 million
inhabitants and serves as the 3rd largest economy in Central America (www.cia.gov). El Salvador
is vulnerable to tropical storms, hurricanes, seismic and volcanic activity (Hall and Brignoli,
2003). One of the major consequences of extreme climatic events, especially hurricanes, is
spread of disease at accelerated rates. According to the World Health Organization, over 2,500
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cases of cholera were reported in 1998 in the Central American Region; approximately half of
these cases were reported after Hurricane Mitch struck in October of 1998 (www.paho.org).
The World Health Organization has identified three areas of serious concern regarding
climate variability and disease in Central America. The first is the increase of vector borne
diseases such as malaria, dengue and yellow fever. The second is water borne diseases like
cholera and diarrheal diseases such as E. coli contaminations. The third is malnutrition which is
coupled with weather disasters, diarrhea, waterborne illnesses and threatened food supplies due
to drought or flooding (Andersen et al., 2010). Other dangers to human health include cardio
respiratory diseases brought on by increased temperatures which can increase particulate matter,
pollen and ozone in the atmosphere, urban areas are exposed to heat island effects which increase
mortality and morbidity especially among the homeless, elderly and poor who lack the means to
take evasive action (Verner, 2010). This research paper is focused on the direct social and
physical effects of ENSO on El Salvador using local station data, climate models, as well as
other factors that make El Salvador a high risk natural disaster area.
2. Background
2.1. Climatology and Physical Geography
The Central American region experiences two distinct seasons: a wet winter season from
May through October and a dry summer season from November to April (Portig, 1965). The area
also presents a bimodal annual cycle of precipitation which means that precipitation reaches a
peak in June then it decreases in July and August, it reaches a second peak in September or
October (Mangaña, 1999). The ministry of environment and natural resources of El Salvador
(Ministerio de Medio Ambiente y Recursos Naturales www.snet.gob.sv) divides the country into
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three separate thermal zones based on elevation. The three thermal zones range from 28oC in the
coastal plains to as low as 10oC in the highest altitudes. Physical drivers of climate in El
Salvador are the northeast trade winds during the dry summer season and the northward
movement of the ITCZ which creates a low pressure system off the Pacific coast bringing rain in
the winter (Haggerty, 1988). During the dry season the high altitudes receive the majority of
their moisture through orographic cloud formation which creates cloud forests along the
Honduran border as well as a small region in the center of the country. The persistent cloud
cover provides precipitation in the dry season and is an important part of the regional hydrologic
cycle (Hall and Brignoli, 2003). Recent increases in temperature indicate the dry season is
becoming drier and the moisture that comes in the form of orographic precipitation coupled with
increasing temperatures creates drought-like conditions (Karmalkar, 2011). This subtropical
region experiences strong wind gusts from the northern Polar Regions of North America. The air
is warmed as it passes over the Gulf of Mexico on its way to Central America, made possible
because of the North American mountain ranges that create a passage way for the air to travel
south (Hall and Brignoli, 2003).
2.2. Climatic events in the last 30 years
Latin America and the Caribbean are among the regions of the world most prone to
climate related hazards (Rossing and Rubin, 2010). Hurricane Mitch 1998 claimed
approximately 11,000 lives and is the strongest October Atlantic hurricane on record (Emanuel,
2005), and it is associated with the 1997-1998 El Niño event and the subsequent La Niña (Verner,
2010). In El Salvador, Hurricane Mitch was responsible for 240 deaths, massive flooding,
mudslides, loss of crops, and the spread of disease (WHO, 1998). In this event, El Salvador had 8
cases of cholera reported, however neighboring countries like Guatemala had over 1,100 cases
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and 33 deaths from cholera reported after Mitch (WHO, 1998). Presence of disease in
neighboring countries make it clear that the country is susceptible to widespread outbreaks, a
susceptibility that may be increased by climate change (Verner, 2010).
According to a United Nations Joint Agency Appeal in October of 2005 a series of
disastrous events triggered the country of El Salvador into a state of emergency. A volcanic
eruption (October 1) followed by torrential rains which were remnants of Hurricanes Rita and
Stan (October 3, 4) wiped out much of that year’s coffee harvest, brought on over 700 mudslides
and forced over 54,000 people to evacuate their homes. The country also experienced a 6.2
magnitude earthquake (October 7) that same week (UN Joint Report, 2005). It is also
noteworthy to observe that in this search no scholarly journals were found that discussed the
disease epidemics or the negative effects of ENSO in El Salvador. Only the United Nations and
the World Health Organization had reports that were available for analysis.
The most recent climatic disaster struck El Salvador in October of 2011. A United
Nations emergency appeal reported that tropical depression 12E (www.nasa.gov) caused heavy
rains in Central America for 10 days affecting over 1.2 million people and killing 100 in the
region. In El Salvador 30 deaths were reported due to landslides, 56,000 people were displaced
in need of food, clean water and sanitation (www.un.org). The UN office for the coordination of
human affairs (OCHA) reported an increase in flood related illnesses such as diarrhea,
conjunctivitis, chicken pox and dengue. Over 69% of the country experienced flood damaged
roads and infrastructure hampering access to remote areas. The agency also expressed concern
for food security since the region was already experiencing high food prices before the floods
which will only be exacerbated by crop losses (OCHA, 2011). The Office of Civil Protection
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reported on October 21, 2011 tropical depression 12E caused the overflow of 132 rivers, 419
landslides, 185 floods, 18 cases of subsidence and 20 sunken areas (www.ifrc.org).
Another main concern regarding rising global temperatures and climate variability is
maintaining biodiversity in certain areas that are declared as hot spots such as parts of Central
America and South America where decline of amphibian populations is strong (Karmalkar et al.,
2011). In Costa Rica the Golden Toad became the first species to be declared victim of global
warming and climate change (Flannery, 2005). The extinction of the Golden Toad coincided
with an exceptionally dry interval caused by the 1986-1987 El Niño. Pounds et al. (2006) argued
that the extinction of the Golden Toad was due to the chytrid fungus that thrived as a result of
changes in climate. The available data did not support the hypothesis that climate change alone
could drive the spread of pathogens, and therefore this theory was later dismissed (Lips et al.,
2008). The Golden Toad relies on the mist that comes in form of orographic precipitation in
order to survive. The 1986-1987 El Niño created a warmer setting in which the high clouds of
Monteverde, Costa Rica remained mistless and led to the extinction of the Golden Toad, the
exact cause however was not discovered until 1999 (Flannery, 2005). El Salvador is home to 87
plants and animals that are considered endangered species IUCN (Glenn, 2006) potential
changes in climate could drive some species to extinction.
2.3. Climate model projections of global warming and ENSO
Several studies have been performed to assess the reliability of climate models to project
future temperature and precipitation in Central America (Karmalkar et al., 2011; Hernandez et al.,
2006). One study compares the Global Climate Model (GCM) (known as a multi data set: MMD)
against a regional climate model called PRECIS (Providing Regional Climates for Impacts
Studies)and found that the GCM severely underestimated precipitation with predictions off by
over 30% in some instances (Karmalkar et al., 2011). Overall the models both struggled in
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simulating ENSO and disagreed on its future behavior. One main conclusion of this study that
both models agreed on are the IPCC (2007) projections regarding overall temperature and
precipitation. Both models indicate that most of the Central American region will experience
drier conditions in the future as the global temperatures increase.
3. Methods
3.1 Analysis of temperature and precipitation of El Niño vs. La Niña events
El Salvador has 6 weather stations that collect temperature and precipitation data. The
station in the nation’s capital of San Salvador has the longest record available. For that reason
the San Salvador station data was used for this study. The first weather station began to take
readings in 1956.
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Figure 3.Time series of maximum and minimum temperature (Tmax, Tmin), dew point
temperature (Tdew) and precipitation at San Salvador from 1956-2010.
There is a large gap of missing records from approximately 1967 through 1973, again
from 1986 to 1994 (Figure 3); both of these periods were times of political unrest and civil war.
The data that was recorded from 1956 to 1967 included maximum/minimum temperatures and
dew point temperature. Precipitation data was not collected until 1974. In addition to the years of
data that are missing mentioned above, there is no precipitation data from 2005 to 2010. The
data used for this research to calculate monthly averages was based on each month having more
than 75% of the day recorded for that month.
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To better understand the effects of ENSO in El Salvador, the San Salvador station data
were analyzed in the context of the NOAA ENSO data. First, we compared mean maximum
temperature fluctuations during the three ENSO phases (El Niño, La Niña, and neutral) (Figure
4).
Figure 4.Monthly mean maximum temperature (Tmax) at San Salvador for El Niño (red), La Niña
(blue) and neutral (black) years.
The final data analyzed for this study are average monthly precipitation totals. The station
in El Salvador that provided these readings is approximately 30 miles inland from the Pacific
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Ocean. Given the topographic variation in the region, the relationships depicted might vary
among regions of El Salvador.
Figure 5.Monthly mean precipitation (PRCP) at San Salvador for El Niño (red), La Niña (blue)
and neutral (black) years.
4. Results and discussion
Based on the information that we have it is clear that El Niño is associated with higher
than average (Tmax) surface air temperatures. ENSO does not seem to be associated with large
variations in minimum temperature averages (Tmin) or dew point temperature averages (Tdew)
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(not shown). El Niño is associated with lower than average rainfall during the wet season. La
Niña is also associated with lower rainfall (in relation to the neutral phase) to a lesser extent. La
Niña years also have lower than average surface air temperatures, this anomaly corresponds to
trends observed in the region in the past (Ose and Arakawa, 2011). Of the missing data,
precipitation is extremely valuable and lacking the most. With a more complete record, the
relationship between ENSO phases and precipitation extremes could be better defined. The
increased surface air temperatures recorded in El Salvador during El Niño years correlate with
the El Niño trends observed in other regions (Karnauskas and Busalacchi, 2009).This implies
that El Salvador is at higher risk of waterborne disease outbreaks such as diarrhea and cholera in
hot weather, these diseases are highly sensitive to changes in climate (Verner, 2010). Extreme
weather events such as floods and heavy rains increase the incidence of waterborne diseases,
after the 1997-98 ENSO event, a time series analysis showed an 8% increase in admissions due
to diarrhea for each 1oC increase in temperature in the Central American region (WHO 2003).
Rising temperatures may lengthen the season, or alter the geographical distribution of
waterborne diseases, much of the protozoa viruses and bacteria that cause them thrive in warm
water and weather (Andersen et al., 2011).
El Niño years leave behind a pattern of disease. Following the 1997-98 El Niño a great
spike occurred in the cases of both malaria and dengue fever. After the 2002-03 El Niño, the
number of dengue cases reached record levels in Central America; dengue has the most severe
impacts in children ages 5-9 (Verner, 2010). The torrential rains of October 2011 do coincide
with a La Niña event. In 2011 NOAA marked the August, September, October season as the first
La Niña anomaly of the late year (www.cpc.ncep.noaa.gov). We cannot say definitively that La
Niña is responsible of the extreme weather of October 2011, but with better monitoring, we
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could look for trends in the ENSO phenomenon that could help governments and NGO’s prepare
for catastrophes.
5. Conclusion
In order to protect the people and environment of El Salvador resources need to be
allocated for better monitoring of weather and climate in the country. Using data from a single
station is limiting because it cannot represent all the variations that occur in a country that ranges
from 0m at sea level to 2,700m in elevation (www.snet.gob.sv). While ENSO appears to have an
effect of rainfall reduction in El Salvador, the neutral climate experiences higher rainfall levels
that are sometimes associated with hurricane activity in the Atlantic such as hurricanes Rita and
Stan in 2005, which was a neutral ENSO year.
The probability of disease spreading at elevated rates is higher during periods of above
average precipitation and climatic distress combined with rising global temperatures (Verner,
2010). El Salvador is home to over 300 rivers many of which are prone to flooding (Haggerty,
1988). Prolonged precipitation is a large factor responsible for land/mudslides in many regions of
El Salvador and other parts of Central America. On September 19, 1982 after a receiving 223mm
of rain in 2 days the land on the slopes of the San Salvador volcano began to move, a mass of an
estimated 220,000𝑚3 dropped on to the capital city in a neighborhood called Montebello killing
500 and leaving 2,400 homeless(CEPRODE, 1994). The 1982 event was during an El Niño year,
based on our research the precipitation was not at higher than normal level however it was 3
months after a 7.3 magnitude earthquake which is said to have created cracks in the slopes
(Bommer et al., 2011). It is also noteworthy to point out that all climatic data for 1982 and much
of 1983 is missing, possibly due to the earthquake and landslide catastrophes that occurred at that
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time, once again this displays the crucial need for good climatic record keeping in the country. El
Salvador faces higher risks overall due to the level of seismic activity, after prolonged rains the
soil is loose and easily shaken by strong earthquakes. The soil is also loose in many regions due
to deforestation which began in the 1960’s at a high rate and peaked in the early 1990’s leaving
behind only2- 5% of natural forest standing in the country (Hetcht, 2005). The United Nations
reported in 2008 that 14% of the land in the El Salvador is forest; this implies that the
reforestation efforts being put in place are slowly working (http://data.un.org) (Hetcht, 2005).
Each El Niño and La Niña event has a different impact and duration, along with other
factors that interact with the climate of Central America and El Salvador. An improvement in
climate data collection for the region is crucial in order to protect the people. Safety and
preparedness will be a major result of continuing to research the vulnerability of the region. It
would be helpful to continue this research and connect climatic records with ENSO records for
the entire 7 Central American countries in order to have a better understanding of how ENSO
affects the area. Another coupling of information could include the interaction of the Indo Pacific
Warm Pool with ENSO in relation to impacts. It is important to evaluate dangers/risk based on
the factors that are present in the area: climate variability, seismic/volcanic activity, hurricanes
and deforestation which put people, plants and animals in danger. When governments and local
authorities use the information that is known about climatic trends for disaster mitigation,
climate science can help save lives.
Works Cited
"UN data | country profile | El Salvador." UN data. N.p., n.d. Web. 4 July 2012.
<http://data.un.org/CountryProfile.aspx?crName=EL%20SALVADOR>.
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Black, Maggie, and Jannet King. The atlas of water. New ed. London: Earthscan, 2009. Print.
Bommer, Julian , Anne Lemonie, Mauricia Ciudad-real, Belen Benito, Manuel Lopez-Menjivar,
Raul Madariaga, Joseph Mankelow, Patricia Mendez de Hasbun, William Murphy,
Mario Nieto-Lovo, Carlos Rodriguez-Pineda, and Herman Rosa. "The El Salvador
Earthquakes of January and February 2001: Context, characteristics and implications for
seismic risk." Soil Dynamics and Earthquake Engineering 5.22 (2002): 389-419.
"CIA-The World Fact book." www.cia.gov. US Government, n.d. Web. 23 May 2012.
<https://www.cia.gov/library/publications/the-world-factbook/geos/es.html>.
"Centro de Proteccion para Desastres." Centro de Proteccion para Desastres. CEPRODE (1994),
n.d. Web. 4 June 2012. <http://ceprode.org.sv/>.
"Clima en El Salvador." Ministerio de Medio Ambiente Y Recursos Naturales. El Salvador
Government Agency, n.d. Web. 22 May 2012.
<www.snet.gob.sv/ver/meteorologia/clima+en+el+salvador/>.
"Climate Prediction Center - Monitoring & Data: ENSO Impacts on the U.S. - Previous Events."
Climate Prediction Center. N.p., n.d. Web. 28 May 2012.
<http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml
>.
Dow, Kirstin, and Thomas E. Downing. The atlas of climate change: mapping the world's
greatest challenge. Berkeley: University of California Press, 2006.
Emanuel, Kerry A. Divine wind: the history and science of hurricanes. Oxford: Oxford
University Press, 2005.
"Emergency Appeal El Salvador: floods." International Federation of Red Cross and Red
Crescent Societies. N.p., n.d. Web. 27 June 2012.
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Mercedes Gomez Jacobo
Faculty Mentor: Dr. Justin Schoof
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<www.ifrc.org/docs/appeals/11/MDRSV004ea.pdf>.
Flannery, Tim F. "A Warning from the Golden Toad." The weather makers: the history and
future impact of climate change. Melbourne: Text Publishing, 2005. 114.
Glenn, C.R. "Endangered Species in El Salvador." Earth's Endangered Creatures. N.p., n.d.
Web. 3 June 2012. <http://www.earthsendangered.com/searchregions3.asp?search=1&sgroup=allgroups&ID=120>.
Haggerty, Richard A. El Salvador: a country study. 2nd ed. Washington, D.C.: The Division,
1990.
Hall, Carolyn, and Hector Brignoli. Historical atlas of Central America. Norman: University of
Oklahoma Press, 2003.
Hernandez, Jose L., Jayanthi Srikishen, David J. Erickson III, Robert Oglesby, and Daniel Irwin.
"A Regional Climate Study of Central America using the MM5 Modeling System:
Results and Comparisons to Observations." International Journal of Climatology 26
(2006): 2161-2179.
"Hurricane Lester - October 13-22, 1998." Hydrometeorological Prediction Center (HPC) Home
Page. United States Government, n.d. Web. 9 June 2012.
<http://www.hpc.ncep.noaa.gov/tropical/rain/lester1998.html>.
"Infectious Diseases Posing the Greatest Epidemiological Risk Following Hurricane Mitch in
Central America 7 December 1998." PAHO/WHO - OPS/OMS. World Health
Organization, n.d. Web. 10 June 2012.
<http://www.paho.org/english/ped/pedep07.htm#top>.
Kane, R.P. "Rainfall Extremes in Some Selected Parts of Central America and South America:
ENSO and Other Relationships Reexamined." International Journal of Climatology 19
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Mercedes Gomez Jacobo
Faculty Mentor: Dr. Justin Schoof
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(1999): 423-455.
Karmalkar, Ambarish V., Raymond S. Bradley, and Henry F. Diaz. "Climate change in Central
America and Mexico: regional climate model validation and climate change
projections." Climate Dynamics 37.3-4 (2011): 605-629. www.springerlink.com.
Karnauskas, Kristopher B., and Antonio J. Busalacchi. "The Role of SST in the Eastern Pacific
Warm Pool in the Interannual Variability of Central American Rainfall." Journal of
Climate 15 (2009): 2605-2623.
Klotzbach, Philip J. "The Influence of El Nino Southern Oscillation and the Atlantic
Multidecadal Oscillation on Caribbean Tropical Cyclone Activity." Journal of Climate
24.3 (2011): 721-731.
"Landslides in Central America." Landslide Hazards Program. US Geological Survey, n.d. Web.
4 July 2012. <http://landslides.usgs.gov/research/other/centralamerica.php>.
Lips, KR, JRM III Diffendorfer, and MW Sears. "Riding the Wave: Reconciling the Roles of
Disease and Climate Change in Amphibian Declines." Public Library of Science Biology
6.3 (2008): e72.
Magaña, V, JA Amador, and S Medina. "The Midsummer Drought Over Mexico and Central
America." Journal of Climate 12.6 (1999): 1577-1588.
"NASA - Hurricane Season 2011: Tropical Depression 12E (Eastern Pacific Ocean)." NASA Home. N.p., n.d. Web. 19 June 2012.
<http://www.nasa.gov/mission_pages/hurricanes/archives/2011/h2011_td12e.html>.
Nagura, Motoki, Kentaro Ando, and Keisuke Mizuno. "Pausing of the ENSO Cycle: A Case
Study from 1998-2002." Journal of Climate 21 (2007): 342-363.
Portig, WH. "Central American Rainfall." Geography Review 65 (1965): 68-90.
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Mercedes Gomez Jacobo
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07/25/12
Pounds, JA, MR Bustamante, SR Ron, GA Sanchez-Azofeifa, CJ Still, BE Young, LA Coloma,
JA Consuegra, MPL Fogden, PM Foster, E LaMarca, KL Masters, A Merino-Viteri, and
R Puschendorf. "Widespread Amphibian Extinctions from Epidemic Disease Driven by
Global Warming." Nature 439. (7073) (2006): 161-167.
Samson, J, D Berteaux, B.J. McGill, and M.M. Humphries. "Geographic disparities and moral
hazards in the predicted impacts of climate change on human population." Global
Ecology and Biogeography 20 (2011): 532-544. http://wileyonlinelibrary.com. Web. 15
May 2011.
"UN agencies step up assistance to flood-ravaged El Salvador." Welcome to the United Nations:
It's Your World. N.p., n.d. Web. 4 July 2012.
<http://www.un.org/apps/news/story.asp?NewsID=40195&Cr=&Cr1>.
"United Nations Statistics Division- Standard Country and Area Codes Classifications (M49)."
United Nations Statistics Division. N.p., n.d. Web. 11 June 2012.
<http://unstats.un.org/unsd/methods/m49/m49regin.htm>.
Verner, Dorte, and Lykke Andersen. Reducing poverty, protecting livelihoods, and building
assets in a changing climate: social implications of climate change in Latin America and
the Caribbean. Washington, D.C.: World Bank, 2010.
Xu, Haiming, Shang-Ping Xie, Yuquing Wang, and R. Justin Small. "Effects of Central
American Mountains on Eastern Pacific Winter ITCZ and Moisture Transport." Journal
of Climate 18 (2005): 3856-3873.
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