Mineral Depletion:
SOIL:
is the prime source of minerals on which every living cell depends for its structure and function. Vitamins, enzymes, amino acids (protein) and a host of other biologically active substances are essential for our bodies to function properly. They virtually all include minerals as an integral part of their chemical structure. Dr Linus Pauling, twice noble prize winner, said “you can trace every sickness, every disease and every ailment to a mineral deficiency”. Yet, all over the world, minerals are disappearing from agricultural soils at an alarming rate. In 1992, the official report of the Rio Earth Summit concluded “there is deep concern over continuing major declines in the mineral values in farm and range soils throughout the world”. This statement was based on data showing that over the last 100 years, average mineral levels in agricultural soils had fallen worldwide – by 72% in Europe, 76% in Asia and 85% in North America. What has caused this staggering decline?
Most of the blame lies with artificial chemical fertilisers. We now know that plants absorb 70 to 80 different minerals from the soil, while the number returned to it by plants grown with commercial fertilisers can be counted on the fingers of one hand. Every crop that is cut or animal that is sent to market marks a further depletion in the mineral status of the soil on which it was raised. Organic wastes that in former times would have been composted and returned to the land are nowadays mostly consigned to landfill sites or incineration.
Pesticides and herbicides :Most of the blame lies with artificial chemical fertilisers. We now know that plants absorb 70 to 80 different minerals from the soil, while the number returned to it by plants grown with commercial fertilisers can be counted on the fingers of one hand. Every crop that is cut or animal that is sent to market marks a further depletion in the mineral status of the soil on which it was raised. Organic wastes that in former times would have been composted and returned to the land are nowadays mostly consigned to landfill sites or incineration.
also reduce the uptake of trace minerals by plants. Plants have an important relationship with certain fungi that can form networks covering several acres. The fungus obtains carbohydrates from the plant root, at the same time supplying the plant with nutrients it draws from the soil. This gives the plant access to a vastly greater mineral extraction system than is possible by their roots alone. Chemical fungicide sprays destroy these beneficial fungi and so again reduce the ability of plants to absorb soil minerals. Insecticides can also reduce trace mineral uptake by inactivating choline-containing enzymes in plants, essential for the absorption of manganese and other minerals.
The combined effect of soil mineral depletion and the reduced availability of those minerals that remain is that most of the food that we eat is mineral deficient. The table below summarizes the reductions in the average mineral content of 27 vegetables and 17 fruits, between 1940 and 1991. The results of the latest research are expected to show mineral values in continual decline.
A new study published earlier this year shows that, as might be expected, mineral levels in animal products reflect the picture in plant foods. Comparing levels measured in 2002 with those present in 1940, the iron content of milk was found to be 62% less, calcium and magnesium in parmesan cheese had each fallen by 70% and copper in dairy produce had plummeted by a remarkable 90%.
The UK government is putting resources into improving health by encouraging people to eat a healthy diet, including 5 portions of fruit and vegetables per day, but you scarcely hear a word about the problem of soil mineral depletion. Food seems to be considered as something quite separate from its source and means of production. But this is not rocket science – the foundation of human health is the quality of the food we eat, which relies ultimately on the vitality of the soil on which it is raised.
The combined effect of soil mineral depletion and the reduced availability of those minerals that remain is that most of the food that we eat is mineral deficient. The table below summarizes the reductions in the average mineral content of 27 vegetables and 17 fruits, between 1940 and 1991. The results of the latest research are expected to show mineral values in continual decline.
A new study published earlier this year shows that, as might be expected, mineral levels in animal products reflect the picture in plant foods. Comparing levels measured in 2002 with those present in 1940, the iron content of milk was found to be 62% less, calcium and magnesium in parmesan cheese had each fallen by 70% and copper in dairy produce had plummeted by a remarkable 90%.
The UK government is putting resources into improving health by encouraging people to eat a healthy diet, including 5 portions of fruit and vegetables per day, but you scarcely hear a word about the problem of soil mineral depletion. Food seems to be considered as something quite separate from its source and means of production. But this is not rocket science – the foundation of human health is the quality of the food we eat, which relies ultimately on the vitality of the soil on which it is raised.
Minerals
are needed for the proper formation of blood and bone, the maintenance of healthy nerve function, heartbeat regulation, reproduction and foetal development. They are essential to the process of growth, healing and energy release. And it is not just the presence of the mineral in the body that is important – they must be in the correct ratio to each other. The level of each mineral has an effect, directly or indirectly, on every other, so if one is out of kilter the whole system is affected.
Minerals are an essential part of our natural diet and a lack of them may in part account for our increasing susceptibility to the “diseases of civilisation” – such as heart disease (magnesium), cancer (selenium), diabetes (chromium) and mental illnesses (zinc). Every one of us should take care to get the minerals we need, for the good of our health.
Minerals are an essential part of our natural diet and a lack of them may in part account for our increasing susceptibility to the “diseases of civilisation” – such as heart disease (magnesium), cancer (selenium), diabetes (chromium) and mental illnesses (zinc). Every one of us should take care to get the minerals we need, for the good of our health.
Deforestation Philippines Forest Figures ------------------------------------------------------------------ Forest CoverTotal forest area: 7,162,000 ha % of land area: 24% ------------------------------------------------------------------ Primary forest cover: 829,000 ha % of land area: 2.8% % total forest area: 11.6% ------------------------------------------------------------------ Deforestation Rates, 2000-2005Annual change in forest cover: -157,400 ha Annual deforestation rate: -2.1% Change in defor. rate since '90s: -20.2% Total forest loss since 1990: -3,412,000 ha Total forest loss since 1990:-32.3% ------------------------------------------------------------------ Primary or "Old-growth" forests Annual loss of primary forests: n/a Annual deforestation rate: n/a Change in deforestation rate since '90s: n/a Primary forest loss since 1990: n/a Primary forest loss since 1990:0.0% ------------------------------------------------------------------ Forest ClassificationPublic: 89.5% Private: 10.5% Other: n/a Use Production: 75% Protection: 11% Conservation: 12% Social services: n/a Multiple purpose: n/a None or unknown: 2 ------------------------------------------------------------------ Forest Area BreakdownTotal area: 7,162,000 ha Primary: 829,000 ha Modified natural: 5,713,000 ha Semi-natural: n/a Production plantation: 304,000 ha Production plantation: 316,000 ha ------------------------------------------------------------------ PlantationsPlantations, 2005: 620,000 ha % of total forest cover: 8.7% Annual change rate (00-05): -46,400,000 ha ------------------------------------------------------------------ Carbon storageAbove-ground biomass: 1,566 M t Below-ground biomass: 376 M t ------------------------------------------------------------------ Area annually affected byFire: 6,000 ha Insects: n/a Diseases: 1,000 ha ------------------------------------------------------------------ Number of tree species in IUCN red listNumber of native tree species: 3,000 Critically endangered: 46 Endangered: 35 Vulnerable: 134 ------------------------------------------------------------------ Wood removal 2005Industrial roundwood: 403,000 m3 o.b. Wood fuel: 138,000 m3 o.b. ------------------------------------------------------------------ Value of forest products, 2005Industrial roundwood: $60,272,000 Wood fuel: $722,000 Non-wood forest products (NWFPs): n/a Total Value: $60,994,000 ------------------------------------------------------------------
Almost two decades after the Catholic Church leaders warned against an ecological debacle in the country, the disappearance of forests remains. Between 1990 and 2005, the Philippines lost one-third of its forest cover. The current deforestation rate is around 2% per year, a 20 % drop from the rate of the 1990s.
“No one says there is an increase in real forest cover in the Philippines. Maybe there is an increase in the number of trees, but it is not the forest we idealize, romanticize, log or even live in,” says Peter Walpole, executive director of the Ateneo de Manila University's Environmental Science for Social Change. “We have lost most of our forest of hold over the past 50 years and, along with them, many of the ecological services they provide.”
“No one says there is an increase in real forest cover in the Philippines. Maybe there is an increase in the number of trees, but it is not the forest we idealize, romanticize, log or even live in,” says Peter Walpole, executive director of the Ateneo de Manila University's Environmental Science for Social Change. “We have lost most of our forest of hold over the past 50 years and, along with them, many of the ecological services they provide.”
According to the Department of Environment and Natural Resources (DENR), the principal cause of the decimation of the country’s forest cover are logging (both legal and illegal), shifting cultivation (locally known as kaingin), forest fires, natural calamities (like earthquake),
as well as conversion to agricultural lands, human settlements and other land uses brought about by urbanization and increasing population pressure.
as well as conversion to agricultural lands, human settlements and other land uses brought about by urbanization and increasing population pressure.“Deforestation is a symptom of a bigger problem,” says Nicolo del Castillo, an architect by profession who teaches at the University of the Philippines. “ I probably sound tacky and outdated, but I see the problem in the prevailing system of values, that is, the greed, the need to be the biggest, the wealthiest, and sometimes you feel hopeless. I am an optimist, but possibly there will be more tragedies and maybe then more people will wake up.”
The removal of forest cover makes the Philippines susceptible to various environmental catastrophes. “Most of these were not seen in such intensity and magnitude before our time,” deplored Roy C. Alimoane, the current director of the Davao-based Mindanao Baptist Rural Life Center Foundation, Inc. “The signs cry out for immediate, nationwide attention.”
Deforestation has been increasingly blamed for soil erosion. Although not considered a serious threat, it is an unseen scourge. “Soil erosion is an enemy to any nation – far worse than any outside enemy into a country and conquering it because it is an enemy you cannot see vividly," warned Harold R. Watson, an American agriculturist who received a Ramon Magsaysay Award in 1985 for peace and international understanding. “It’s a slow creeping enemy that soon possesses the land.”
At least two provinces – Cebu and Batangas – have lost more than 80% of their topsoil to erosion. In Luzon, four major basins --- Bicol, Magat, Pampanga, and Agno – are in critical condition due to acute soil erosion and sedimentation.
The rampant cutting of trees has also significantly reduced the volume of groundwater available for domestic purposes. “If the forest perishes, so will the life of people,” said Diosmedes Demit, one of the farmers who joined the ‘Fast for the Forests’ in 1989. “The trees are our source of life. Without trees, there will be no water. If there is no water, there will be no life.”
Cebu, which has zero forest cover, is 99% dependent on groundwater. As a result, more than half of the towns and cities in Cebu, excluding Metro Cebu, have no access to potable water. In Metro Manila, where there are no forests to speak of, the water tables are being drawn at the rate of six to 12 meters a year causing saline water intrusion along the coastal areas.
Deforestation also brings too much water – in case of constant rain. “Rain which falls over a bare slope acts differently,” Gifford Pinchot wrote in A Primer for Forestry. “It is not caught by the crowns nor held by the floor, nor is its flow into the streams hindered by the timber. The result is that a great deal of water reaches the streams in a short time, which is the reason why floods occur.”
Remember the Ormoc tragedy in Leyte? More than five thousand people were reported to have perished from flash foods, injuring 292 others with 1,264 missing. The reported total cost of damage was P1.044 billion.
Deforestation also threatens the country’s wildlife resources. Two particular species of animals, the tamaraw and the Philippines eagle are almost extinct due to the massive deforestation. More than half the birds, amphibians and mammals endemic to the Philippines are threatened with extinction.
DENR’s Joselito Atienza said that 592 of the 1,137 species of amphibians, birds and mammals found only in the Philippines are considered “threatened or endangered.” Some 227 endemic species of plants are “critically endangered.”
Coral Bleaching
Ten percent of the world's reefs have been completely destroyed. In the Philippines, where coral reef destruction is the worst, over 70% have been destroyed and only 5% can be said to be in good condition. What has happened to destroy all of the reefs? Humans have happened.
There are two different ways in which humans have contributed to the degradation of the Earth's coral reefs, i
ndirectly and directly. Indirectly, we have destroyed their environment. As you read earlier, coral reefs can live only within a certain temperature and salinity range. Global warming caused by the green house effect has raised the temperature of the oceans so high that the coral get sick and die. Even a rise of one degree in the average water temperature can hurt the coral. Due to global warming, 1998 was the hottest year in the last six centuries and 1998 was the worst year for coral.The most obvious sign that coral is sick is coral bleaching. That is when either the algae inside die, or the algae leave the coral. The algae are what give coral its color, so without the algae the coral has no color and the white of the limestone shell shines through the transparent coral bodies. People have been noticing coral bleaching since the turn of the century, but only since the 1980s has it gotten really bad.
The warmer water also encourages the growth of harmful algae on top of the coral, which kills it, because it blocks out the sun. Without the sun, the zooxanthellae cannot perform photosynthesis and so they die. Without the zooxanthellae, the coral polyps die too. This algae is usually eaten by fish, but because of over fishing, there aren't enough fish left to eat all the algae. And the pollution we dump in the ocean is just what the algae needs to grow and be healthy, which means covering and eventually killing the coral reefs.
The direct way in which humans destroy coral reefs is by physically killing them. All over the world, but especially in the Philippines, divers catch the fish that live in and around coral reefs. They sell these fish to fancy restaurants in Asia and to fancy pet stores in the United States. This would be OK if the divers caught the fish carefully with nets and didn't hurt the reefs or take too many fish. But the divers want lots of fish and most of them are not very well trained at fish catching. Often they blow up a coral reef with explosives (picture below) and then catch all the stunned fish swimming around. This completely destroys the reefs, killing the coral polyps that make it as well as many of the plants and animals that call it home. And the creatures that do survive are left homeless.
Another way that divers catch coral reef fish is with cyanide. Cyanide is a poison. The divers pour this poison on the reef, which stuns the fish and kills the coral. Then they rip open the reef with crowbars and catch the fish while they are too sick from the poison to swim away. This poison kills 90% of the fish that live in the reef and the reef is completely destroyed both by the poison and then by being ripped apart.
All this may seem a bit depressing, but there are many groups in the world dedicated to saving the coral reefs. These groups work to educate people about the destruction of coral reefs. They lobby the United States Congress as well as the governments of other nations, trying to convince them not to buy fish that have been caught by destroying coral reefs. They encourage governments to crack down on pollution, both into the ocean and into the air, which causes global warming. They encourage visitors to coral reefs to be careful not to harm them. They even build artificial reefs to replace the reefs that have been destroyed. If you want to learn more about these groups, visit some of their websites, like the Coral Reef Alliance, Reef Relief, and the Planetary Coral Reef Foundation.
The warmer water also encourages the growth of harmful algae on top of the coral, which kills it, because it blocks out the sun. Without the sun, the zooxanthellae cannot perform photosynthesis and so they die. Without the zooxanthellae, the coral polyps die too. This algae is usually eaten by fish, but because of over fishing, there aren't enough fish left to eat all the algae. And the pollution we dump in the ocean is just what the algae needs to grow and be healthy, which means covering and eventually killing the coral reefs.
The direct way in which humans destroy coral reefs is by physically killing them. All over the world, but especially in the Philippines, divers catch the fish that live in and around coral reefs. They sell these fish to fancy restaurants in Asia and to fancy pet stores in the United States. This would be OK if the divers caught the fish carefully with nets and didn't hurt the reefs or take too many fish. But the divers want lots of fish and most of them are not very well trained at fish catching. Often they blow up a coral reef with explosives (picture below) and then catch all the stunned fish swimming around. This completely destroys the reefs, killing the coral polyps that make it as well as many of the plants and animals that call it home. And the creatures that do survive are left homeless.
Another way that divers catch coral reef fish is with cyanide. Cyanide is a poison. The divers pour this poison on the reef, which stuns the fish and kills the coral. Then they rip open the reef with crowbars and catch the fish while they are too sick from the poison to swim away. This poison kills 90% of the fish that live in the reef and the reef is completely destroyed both by the poison and then by being ripped apart.
All this may seem a bit depressing, but there are many groups in the world dedicated to saving the coral reefs. These groups work to educate people about the destruction of coral reefs. They lobby the United States Congress as well as the governments of other nations, trying to convince them not to buy fish that have been caught by destroying coral reefs. They encourage governments to crack down on pollution, both into the ocean and into the air, which causes global warming. They encourage visitors to coral reefs to be careful not to harm them. They even build artificial reefs to replace the reefs that have been destroyed. If you want to learn more about these groups, visit some of their websites, like the Coral Reef Alliance, Reef Relief, and the Planetary Coral Reef Foundation.
PHILIPPINES MANGROVE ECOSYSTEM & BIODIVERSITY
Mangroves - are salt-tolerant, woody, seed-bearing plants that are found in tropical and subtropical areas where they are subject to periodic tidal inundation. The Philippines has over 40 species of mangroves and is one of the most biodiverse regions in the world as there are only about 70 species of mangroves worldwide. The mangrove ecosystem is a very diverse one and is home to many birds, fish, mammals, crustaceans and other animals.
ROOT SYSTEM
Mangroves are very specialized plants and have adapted to survive in a very harsh environment where other plants cannot survive. An example of an interesting adaptation is the root system of mangroves. Since mangroves often live in muddy environments where gas exchange is difficult, the root systems of many mangrove species are highly specialized. One example of this is pneumatophores or breathing roots which look like fingers sticking out of the ground which are seen on Avicennia spp. (api-api) and Sonneratia spp. (pagatpat) trees. Other roots which grow out from branches and the trunk of mangrove trees such as those on Rhizophora spp. (bakaun) are called stilt or prop roots. These roots contain lenticels or breathing holes which allow gas exchange above the ground. These stilt roots also provide support and anchorage during high winds and wave action as well as serving as an attachment substrate for many marine organisms. Other species have knee or knob roots above the ground such as seen in Busain.
ADAPTATIONS: EXCRETERS/EXCLUDERS
PROPAGULES
Mangroves also have adapted certain reproductive mechanisms to deal with the harsh salt water environment. One of these is the viviparous propagule or tungki found on bakuan. This propagule is already germinated on the tree and has a basic stem structure and can therefore easily be implanted in the substrate and quickly begin to grow. If the propagule does however fall in the water it has the ability to float for up to one year which aids greatly in dispersal of mangrove species.
FOOD FOR MARINE ORGANISMS
Mangroves - are salt-tolerant, woody, seed-bearing plants that are found in tropical and subtropical areas where they are subject to periodic tidal inundation. The Philippines has over 40 species of mangroves and is one of the most biodiverse regions in the world as there are only about 70 species of mangroves worldwide. The mangrove ecosystem is a very diverse one and is home to many birds, fish, mammals, crustaceans and other animals.
ROOT SYSTEM
Mangroves are very specialized plants and have adapted to survive in a very harsh environment where other plants cannot survive. An example of an interesting adaptation is the root system of mangroves. Since mangroves often live in muddy environments where gas exchange is difficult, the root systems of many mangrove species are highly specialized. One example of this is pneumatophores or breathing roots which look like fingers sticking out of the ground which are seen on Avicennia spp. (api-api) and Sonneratia spp. (pagatpat) trees. Other roots which grow out from branches and the trunk of mangrove trees such as those on Rhizophora spp. (bakaun) are called stilt or prop roots. These roots contain lenticels or breathing holes which allow gas exchange above the ground. These stilt roots also provide support and anchorage during high winds and wave action as well as serving as an attachment substrate for many marine organisms. Other species have knee or knob roots above the ground such as seen in Busain.
ADAPTATIONS: EXCRETERS/EXCLUDERS
Mangroves must also deal with the saltwater environment that they live in. While many mangrove trees grow best in a mixture of saltwater, an excessive amount of salt would certainly kill them. In order to deal with this mangrove species have developed a number of different adaptations. Certain trees such as api-api are excreters and they expel salt crystals from their leaves which is then washed away by the rain. Others are excluders and block salt from entering through their roots. They accomplish this by having a high innate concentration of salt in their roots which prevents water from entering against the osmotic gradient. Other plants are secluders which concentrate salt in certain leaves which turn yellow and die and expel the salt when these leaves die.
PROPAGULES
Mangroves also have adapted certain reproductive mechanisms to deal with the harsh salt water environment. One of these is the viviparous propagule or tungki found on bakuan. This propagule is already germinated on the tree and has a basic stem structure and can therefore easily be implanted in the substrate and quickly begin to grow. If the propagule does however fall in the water it has the ability to float for up to one year which aids greatly in dispersal of mangrove species.
FOOD FOR MARINE ORGANISMS
Mangroves provide an important nursery for fish, shellfish and other organisms. It is estimated that each hectare of mangrove produces 3,600 kg of litterfall which provides food for 1,000 kg of marine organisms. With the abundance of food for fish present in the mangroves, each year one hectare of forest yields 283.5 metric tons of fish per year. Mangroves also provide other important functions such as preventing soil erosion and protecting shoreline from typhoons and strong waves. Mangroves provide many other products and services such as medicines, alcohol, housing materials and are an area for research and tourism.
THREATS
Even with all of these known benefits the state of mangroves within the Philippines is very dim. In the early 1900’s there were approximately 500,000 hectares of mangroves but today there are only about 120,000 hectares. Many of the mangrove areas were destroyed to make way for fishponds and reclamation areas. They were used indiscriminately for housing materials and were disturbed by siltation and pollution. Now that the true benefit of these ecosystems is known there is protection and rehabilitation of these important ecosystems. It is now illegal to cut down mangroves for any purpose and local governments and community organizations have taken active roles in planting and managing mangrove plantations. There is hope that in the future mangroves will return to the healthy status that they once held in the past.
THREATS
Even with all of these known benefits the state of mangroves within the Philippines is very dim. In the early 1900’s there were approximately 500,000 hectares of mangroves but today there are only about 120,000 hectares. Many of the mangrove areas were destroyed to make way for fishponds and reclamation areas. They were used indiscriminately for housing materials and were disturbed by siltation and pollution. Now that the true benefit of these ecosystems is known there is protection and rehabilitation of these important ecosystems. It is now illegal to cut down mangroves for any purpose and local governments and community organizations have taken active roles in planting and managing mangrove plantations. There is hope that in the future mangroves will return to the healthy status that they once held in the past.
El Nino and La Nina Weather Disturbances, Typhoons (Phil Setting)
El Niño/La Niña
In a previous Economic Issue of the Day (Vol. V, No. 1, July 2005), a basic understanding was presented on what the El Niño southern oscillation (ENSO) phenomenon is all about, its characteristics and two phases, and its implications.
ENSO is a phenomenon that takes place in the central and eastern equatorial Pacific largely characterized by an interaction between the ocean and the atmosphere and their combined effect on climate. The mutual interaction between the ocean and the atmosphere is a critical aspect of the ENSO phenomenon.
Major ENSO indicators are the sea surface temperature anomaly (SSTA) and the southern oscillation index (SOI). SSTA refers to the departure or difference from the normal value in the sea or ocean surface temperature. El Niño events are characterized by positive values (greater than zero) within a defined warm temperature threshold while La Niña events are characterized by negative values (less than zero) within a defined cold temperature threshold.
The SOI, on the other hand, measures the differences or fluctuations in air or atmospheric pressure that occur between the western and eastern tropical Pacific during El Niño and La Niña episodes. It is calculated on the basis of the differences in air pressure anomaly between Darwin in Australia (western Pacific) and Tahiti in French Polynesia (eastern Pacific). These two locations/stations are used in view of their having long data records.
Albeit the seeming straightforward description of these ENSO-related events as noted in the above, it is to be emphasized that through the years, it has not been easy to come up with a commonly agreed definition and identification of these ENSOrelated events, i.e., El Niño or La Niña. The reason is due to the use of more than one standard index as basis in monitoring ENSO phenomena and the employ of different methods in determining the magnitude or value of such index and threshold as well as the length of time that such magnitude persists. In line with this, the Philippines adopted the World Meteorological Organization (WMO) Regional Association IV Consensus Index and Definitions of El Niño and La Niña. Region IV includes the North and Central America member nations of the WMO, whose operational definitions in use of the two ENSO phases are the following:
El Niño: A phenomenon in the equatorial Pacific Ocean characterized by a positive SST departure from normal (for the 1971-2000 base period) in the Niño 3.4 region, greater than or equal in magnitude to 0.5 degrees C, and averaged over three consecutive months. Defined when the threshold or value is met for a minimum of five consecutive overlapping seasons.
La Niña: A phenomenon in the equatorial Pacific Ocean characterized by a negative SST departure from normal (for the 1971-2000 base period) in the Niño 3.4 region greater than or equal in magnitude to 0.5 degrees C, and averaged over three consecutive months. Defined when the threshold or value is met for a minimum of five consecutive overlapping seasons.
When is El Niño/La Niña occurring?
Because ENSO-related phenomena have been a major source of interannual climate variability around the globe, especially in recent years, it is important to be able to determine or identify when an El Niño/La Niña is occurring or will take place.
As noted earlier, monitoring the occurrence of an El Niño/ La Niña involves the use of two most common indicators, the SSTA and the SOI, with the SSTA based on the magnitude of departures/anomalies in the sea surface temperature in the Niño regions (see box), and the SOI based on the difference in air pressure between Tahiti and Darwin.
PAGASA: monitoring El Niño/La Niña events in the Philippines
In the Philippines, how is El Niño/La Niña identified/monitored? The country’s national meteorological agency, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), defines and identifies these phenomena on the basis of the abovementioned indicators which are also being used by the National Oceanic and Atmospheric Administration-National Centers for Environmental Prediction
(NOAA-NCEP) of the United States.
Typhoons in the Philippines
Describes the most notable tropical cyclones to enter the Philippine Area of Responsibility and affect the Philippines. Bagyo is a term referring to any tropical cyclone in the Philippine Islands. An average of 6 to 7 tropical cyclones hit the Philippines per year. A bagyo is categorized into four types according to its wind speed by the PAGASA. All tropical cyclones, regardless of strength, are named by PAGASA. Tropical depressions have maximum sustained winds of between 55 kilometres per hour (30 kn) and 64 kilometres per hour (35 kn) near its center. Tropical storms have maximum sustained winds of 65 kilometres per hour (35 kn) and 119 kilometres per hour (64 kn). Typhoons achieve maximum sustained winds of 120 kilometres per hour (65 kn) to 185 kilometres per hour (100 kn), with super typhoons having maximum winds exceeding 185 kilometres per hour (100 kn). The most destructive tropical cyclone to impact the Philippines was Tropical Storm Thelma in 1991, which killed thousands of people from its resultant flooding. The wettest known tropical cyclone to impact the archipelago was the July 1911 cyclone which dropped over 1,168 millimetres (46.0 in) of rainfall within a 24 hour period at Baguio City. At least 30 percent of the annual rainfall in the northern Philippines could be traced to tropical cyclones, while the southern islands receive less than 10 percent of their annual rainfall from tropical cyclones
El Niño/La Niña
In a previous Economic Issue of the Day (Vol. V, No. 1, July 2005), a basic understanding was presented on what the El Niño southern oscillation (ENSO) phenomenon is all about, its characteristics and two phases, and its implications.
ENSO is a phenomenon that takes place in the central and eastern equatorial Pacific largely characterized by an interaction between the ocean and the atmosphere and their combined effect on climate. The mutual interaction between the ocean and the atmosphere is a critical aspect of the ENSO phenomenon.
Major ENSO indicators are the sea surface temperature anomaly (SSTA) and the southern oscillation index (SOI). SSTA refers to the departure or difference from the normal value in the sea or ocean surface temperature. El Niño events are characterized by positive values (greater than zero) within a defined warm temperature threshold while La Niña events are characterized by negative values (less than zero) within a defined cold temperature threshold.
The SOI, on the other hand, measures the differences or fluctuations in air or atmospheric pressure that occur between the western and eastern tropical Pacific during El Niño and La Niña episodes. It is calculated on the basis of the differences in air pressure anomaly between Darwin in Australia (western Pacific) and Tahiti in French Polynesia (eastern Pacific). These two locations/stations are used in view of their having long data records.
Albeit the seeming straightforward description of these ENSO-related events as noted in the above, it is to be emphasized that through the years, it has not been easy to come up with a commonly agreed definition and identification of these ENSOrelated events, i.e., El Niño or La Niña. The reason is due to the use of more than one standard index as basis in monitoring ENSO phenomena and the employ of different methods in determining the magnitude or value of such index and threshold as well as the length of time that such magnitude persists. In line with this, the Philippines adopted the World Meteorological Organization (WMO) Regional Association IV Consensus Index and Definitions of El Niño and La Niña. Region IV includes the North and Central America member nations of the WMO, whose operational definitions in use of the two ENSO phases are the following:
El Niño: A phenomenon in the equatorial Pacific Ocean characterized by a positive SST departure from normal (for the 1971-2000 base period) in the Niño 3.4 region, greater than or equal in magnitude to 0.5 degrees C, and averaged over three consecutive months. Defined when the threshold or value is met for a minimum of five consecutive overlapping seasons.
La Niña: A phenomenon in the equatorial Pacific Ocean characterized by a negative SST departure from normal (for the 1971-2000 base period) in the Niño 3.4 region greater than or equal in magnitude to 0.5 degrees C, and averaged over three consecutive months. Defined when the threshold or value is met for a minimum of five consecutive overlapping seasons.
When is El Niño/La Niña occurring?
Because ENSO-related phenomena have been a major source of interannual climate variability around the globe, especially in recent years, it is important to be able to determine or identify when an El Niño/La Niña is occurring or will take place.
As noted earlier, monitoring the occurrence of an El Niño/ La Niña involves the use of two most common indicators, the SSTA and the SOI, with the SSTA based on the magnitude of departures/anomalies in the sea surface temperature in the Niño regions (see box), and the SOI based on the difference in air pressure between Tahiti and Darwin.
PAGASA: monitoring El Niño/La Niña events in the Philippines
In the Philippines, how is El Niño/La Niña identified/monitored? The country’s national meteorological agency, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), defines and identifies these phenomena on the basis of the abovementioned indicators which are also being used by the National Oceanic and Atmospheric Administration-National Centers for Environmental Prediction
(NOAA-NCEP) of the United States.
Typhoons in the Philippines
Describes the most notable tropical cyclones to enter the Philippine Area of Responsibility and affect the Philippines. Bagyo is a term referring to any tropical cyclone in the Philippine Islands. An average of 6 to 7 tropical cyclones hit the Philippines per year. A bagyo is categorized into four types according to its wind speed by the PAGASA. All tropical cyclones, regardless of strength, are named by PAGASA. Tropical depressions have maximum sustained winds of between 55 kilometres per hour (30 kn) and 64 kilometres per hour (35 kn) near its center. Tropical storms have maximum sustained winds of 65 kilometres per hour (35 kn) and 119 kilometres per hour (64 kn). Typhoons achieve maximum sustained winds of 120 kilometres per hour (65 kn) to 185 kilometres per hour (100 kn), with super typhoons having maximum winds exceeding 185 kilometres per hour (100 kn). The most destructive tropical cyclone to impact the Philippines was Tropical Storm Thelma in 1991, which killed thousands of people from its resultant flooding. The wettest known tropical cyclone to impact the archipelago was the July 1911 cyclone which dropped over 1,168 millimetres (46.0 in) of rainfall within a 24 hour period at Baguio City. At least 30 percent of the annual rainfall in the northern Philippines could be traced to tropical cyclones, while the southern islands receive less than 10 percent of their annual rainfall from tropical cyclones
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