Three Pacific typhoons
at the same time A typhoon is defined as a tropical cyclone in the western Pacific. Typhoons generally track in a westward or northern direction, and occur most frequently in a region of the western Pacific and east Asia that includes the Philippines, Vietnam, Taiwan, southern China, South Korea, southern Japan, Guam, the Marianas Islands and parts of Micronesia. They generally do not occur south of the Philippines and blow themselves out if they travel west of Vietnam or into the interior of China.
A typhoon is essentially the same thing as a hurricane, which is defined as a strong tropical storm with winds over 75 miles per hour, occurring in the west Atlantic and the eastern Pacific, particularly in southeastern North Americas and the Caribbean. Similar storms in the Indian Ocean are called tropical cyclones. Ones that strike Australia are called willie willies. Cyclone is also a catch all phrase which describes all low pressure systems over tropical waters and includes typhoons and hurricanes. All these storms feature super heavy rain as well as high winds.
The word “typhoon” comes from the Cantonese word "tai feng." The approach of a typhoon is heralded by large waves, a storm surge, and falling barometric pressure. As it gets nearer mountains of cumulus clouds appear and wind squalls intensify, climaxing with a sweeping wall of dense clouds with furious winds and torrential rain. Describing a South China Sea storm in 1935, one American captain wrote: "A terrible crash was heard! The vessel trembled like an aspen-leaf...with the sea pouring in over the bow, and the topsails shivering like so many rags." Joseph Conrad described the storms in his novels Lord Jim and Typhoon.
The typhoon season lasts from the early summer to early autumn, often coinciding with the monsoon season in Southeast Asia and the wet season in eastern Japan. The main typhoon and hurricane season is from June to November. Sometimes they appear as early as May and as late as December. Storms can be particularly fierce in years of the El Niño. Usually more damage is caused by the heavy rain than by the winds.
In Japan typhoons are given numbers and are named in order of occurrence. In other Asian countries since 2000 they have been given names. Each member of a group called the Typhoon Committee, comprised of 14 Asian countries, including Japan, provide 10 names for a total of 140 names
Websites and Resources
warning alert in China Links in this Website: LAND AND GEOGRAPHY OF JAPAN Factsanddetails.com/Japan ; CLIMATE AND WEATHER IN JAPAN Factsanddetails.com/Japan ; STORMS, FLOODS AND SNOW IN JAPAN Factsanddetails.com/Japan ; TYPHOONS Factsanddetails.com/Japan ; TYPHOONS IN JAPAN Factsanddetails.com/Japan ; NATURAL RESOURCES AND JAPAN Factsanddetails.com/Japan
Good Websites and Sources on Climate and Weather: Good Photos of the Seasons at Japan-Photo Archive japan-photo.de ; Statistical Handbook of Japan Land and Weather Chapter stat.go.jp/english/data/handbook ; 2010 Edition stat.go.jp/english/data/nenkan ; News stat.go.jp Japan Meteorological Agency Japan Meteorological Agency ; Weather Underground wunderground.com/global/JP ; Weather Channel Weather Channel ;World Climate World Climate ; Accuweather Accuweather ; Climate Data climatetemp.info/japan ;Wikipedia article on Geography of Japan Wikipedia ;
Typhoon Megi in October 2010 Good Websites and Sources of Storms and Floods: Weather Warnings from Japan Meteorological Agency jma.go.jp/en/warn ; Marine Warnings from Japan Meteorological Agency jma.go.jp/en/seawarn ; Wikipedia article on Snow Country in Japan Wikipedia ; Landslide Distribution Map bosai.go.jp/en ; BBC Picture Gallery of Flood in Japan news.bbc.co.uk ; Academic Paper of Flood Maps in Japan internationalfloodnetwork.org ; Tornados in Japan Survey by the American Meteorological Society ams.allenpress.com ; BBC report on 2006 Tornado bbc.co.uk
Typhoons: Typhoon and Hurricane Basics aoml.noaa.gov ; Data and Images from Pacific Typhoons eorc.jaxa.jp/ADEOS Typhoon and Hurricane Satellite Images and Photos fotosearch.com ; Video from Nasty Typhoon in Taiwan YouTube ; Typhoon Video YouTube ; Central Pacific Hurricane Center at the National Weather Service prh.noaa.gov ; Wikipedia article on Tropical Cyclones Wikipedia ; National Hurricane Center at the National Weather Service nhc.noaa.gov ; Jet Propulsion Laboratory Images of Typhoons jpl.nasa.gov/images ;
Typhoons in Japan : Typhoon and Tropical Cyclone Information from the Japan Meteorological Agency Japan Meteorological Agency ; Video of Typhoon Surfing in Japan YouTube ; Brochure on Typhoons in Japan pdf file rms.com/Publications ; Good Japan Times article on Typhoons in Japan search.japantimes.co.jp ; Digital Typhoon Information from the and United States Navy agora.ex.nii.ac.jp/digital-typhoon ; Ise-Wan Typhoon Wikipedia article on the 1959 Ise-wan Typhoon (Typhoon Vera) wikipedia.org/wiki/Typhoon_Vera ; U.S. Navy Report on the 1959 Ise-wan Typhoon pdf file usno.navy.mil and usno.navy.mil ; Lessons from the Isewan Typhoon pdf file katrina.lsu.edu/downloads/Typhoon_Isewan
Hurricanes and typhoons in the northern hemisphere have an eye and thunderstorm-producing cumulus clouds that spiral out in a clockwise direction from the eye. They eye is 5 to 25 miles wide and is relatively calm, sometimes windless. Strong winds blowing towards the center of the area of extreme low pressure and cirrus streamer clouds radiating in a east or southeast direction are bent by the Coriolis affect. The most destructive part of the storm is usually the northern, leading side of the storm. The east side of a typhoon generally is more devastating than the west side.
The “eyewall,” an area just beyond the eye, is the region of the storm with the most intense winds. It is often only a kilometer or so wide but it interacts with the rings of thunderstorms that produce the heaviest winds and rains and its behavior and dynamics are crucial to the behavior of the storm as a whole. The eyewall is shaped by two opposing forces: 1) moist, warm air from inside the eye, which can feed the eyewall, strengthening it; and 2) dry air from outside the eye that can slowly bleed into it, and calm it down.
tropical cyclone zones
Air flowing from high pressure to low pressure causes winds. If the difference between high pressure and low pressure is great, intense circulation is generated, causing a powerful storm. As air spirals into a low-pressure zone warm humid air and warm sea surface winds meet and ascend, causing clouds to billow upwards. Further lowering of air pressure can cause winds to swirl even faster towards the center.
The deflecting action of the Earth’s rotation spins the developing cyclone (counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere). When water in the ascending clouds cools and falls as rain heat energy is produced, which further warms the storm, lowering the pressure and making the storm stronger. The cyclone can continue to strengthen as long as it remains over warm water and is not destroyed by vertical wind shear—winds traveling at different speeds at lower and high altitudes—which can cut off the top of a storm breaking up its energy producing engine.
Types of Typhoons
Supertyphoons are very destructive. They are defined as typhoons with winds over 150 miles per hour. Such storms produce horizontal rain and can measure several hundred miles across, cover thousands of square miles and reach an altitude of almost ten miles. The largest storm on record, the 1979 typhoon Tip, produced gale force across a 650 mile area.
The power generated by a major hurricane or typhoon is said to be equal to half a million nuclear bombs. The power of an average storm is said to be equal to 1.5 trillion watts—the equivalent to about half the world’s entire electrical generating capacity.
Atlantic storms and hurricanes are defined as: 1) a tropical depression; 2) a tropical storm (less than 74 miles per hour); 3) Category One (between 74 and 95 miles per hour); 4) Category Two (between 95 and 110 miles per hour); 3) Category Three (between 111 and 130 miles per hour); Category Four (between 131 and 155 miles per hour); and Category Four (more than 155 miles per hour).
In Asia, different countries have different systems for identifying typhoons. Some countries such as Japan use numbers. Others use names.
Many so called ‘storms seeds” with the potential to become typhoons form in the summer west of the International Date Line in an area of the tropical Pacific at a latitude between 10 and 20 degrees north. They usually begin as westward-drifting “waves” of clouds drawn into an area of low pressure around the Caroline Islands of Micronesia (between Hawaii and the Philippines in the Pacific) and grow into westward-moving tropical depressions.
Because the Caroline Islands of Micronesia are breeding grounds for typhoons they rarely get hit by fully developed storms. Typhoons usually pass north of Palau.
As the clouds advance across the warm water they pick up energy as the water evaporates. At a critical point the clouds develop into a vortex of air that rotates in a counter-clockwise direction because of the Coriolis effect (see above). The water temperatures generally have to be above 80̊F for all this to occur. The warmer the sea surface temperatures are, and the more warm, moist air there is, the stronger the storm will be.
A number of things have to come together for a typhoon to form. Among them are the presence of an initial low-pressure system that pulls the air to a particular spot in the ocean; the Coriolis effect spinning the air in a vortex; differences in wind speed in the upper and lower parts of the atmosphere that create horizontal “shear forces”; and the presence of cold air 10 miles up in the atmosphere.
Factors that influence typhoon development include water temperatures and rainfall amounts in the Pacific; El Niño (which produces high-level winds that blow the top off typhoon clouds); and stratospheric jet-stream wind patterns. Scientist also believe that typhoons can be influenced by seemingly unrelated things like the atmospheric temperatures above Singapore.
According to a study by scientists at the University College London high sea temperatures are the most reliable indicator of increased typhoon and hurricane activity. The reasoning is that warmer seas cause more water to evaporate. As the water rises, latent heat is released which provides the energy for a low pressure cell to develop into a hurricane.
Typhoon Tokage Typhoons are self-feeding and self-reinforcing events fueled by: 1) evaporated water that releases energy when it condenses back into water; and 2) driving rapid updrafts that cause water to evaporate from the ocean, forming self-sustaining vortexes of swirling clouds and high winds. The dynamics of all this—especially of forces than can cause a storm to suddenly intensify—remain little understood. Among the clues that a storm is about to intensify are the presence of chimney clouds called hot towers that can reach as high as 11 milies into the atmosphere.
Rapidly moving air over warm water absorbs unusually large amount of water vapor through evaporation. As the air converge at the center of the storm, it rises. As the air rises, it cools and some of the water vapor condenses into droplets. That process release energy in the form of “heat cf condensation.” [Source: Washington Post, ✳]
The heat is released into a column of air that is already warmer than the air outside the storm. There can be as much as a 30̊F difference between air in the eyewall and air at the same altitude outside the storm. The heat dissipates slowly, in part because the air is contained in a rotating system. Meanwhile, the newly released reheated air continues to rise, eventually losing more moisture and condensation and releasing more heat. In this way a large and powerful typhoon can influence its environment in such a way as to allow the storm to get even bigger and stronger.✳
When the rising air exits from the system, sometimes as high as 50,000 feet above the sea surface, it is cold and relatively dry. As it departs more air is pulled in at the bottom of the storm, continuing the cycle. The energy from the warm water beneath the storm is vital to keeping the whole thing going. When a typhoon goes over cool water or land it tends to fall apart. High upper atmosphere winds are also great typhoon killers. They can sometimes sheer the tops off of a typhoon and cause it to suddenly collapse.
Hurricanes maintain and gain strength over the sea and lose strength when the go overland. Islands are often so small they little effect. The intensity of a storm is also related to its interaction with the sea. Warm water at the top of the ocean provides fuel. As the storm spins, it churns the water beneath it, bringing cooler water from the depths. The cooler water acts as a brake to slow the engine down. Some of the most intense storms are feed by warm water that is hundreds of meters deep and the breaking action of cooler water does not occur. Large waves can also slow a storm down by blunting the winds that created them.
Damage from Typhoons
Typhoon Tokage Typhoons can cause millions or even billions of dollars in damage. Buildings slide down hillsides; valleys flood; villages disappear under landslides and mud slides; roads and bridges are washed away; crops become waterlogged, or are blown over or uprooted, or covered in mud. Destruction levels can be particularly high when a storm stalls and strong, driving rains persist for hours or even days, or when the storm slams into mountains, producing particularly large amounts of rain. Some typhoons are so powerful they blow plankton and small sea creatures into the sky, where they float around on clouds.
Usually much more damage and death is caused by rains than winds. People die from being hit by flying debris or falling trees or crushed in collapsed building but are more likely to die from drowning in flooded rivers or from suffocating under rain-induced mud slides and landslides. Most victims from really deadly storms die from storm surges—masses of ocean water that are pushed forward by the winds—that can penetrate several miles inland. The surges are particularly deadly if they occur at high tide.
Typhoons often do the most damage on low coral islands which are sometimes inundated with waves that can reach a height of 30 meters at sea and storm surges that sweep water across the entire island, annihilating every tree and hut in their path. Modern buildings and houses with cinder block walls and metal roofs are usually strong enough to withstand the winds of strong typhoons but thatched-roof huts and shanties are easily blown over or crushed by falling trees. Palm trees also blow over pretty easily because they don't have a deep root system.
Long term damage and hardships from typhoons are caused by sickness and starvation as water supplies become contaminated; cholera and dysentery; poisonous snakes flooded out of their dens; damaged crops and stored food; and the disruption or destruction of transportation routes used to bring in relief supplies. Over the longer term fields and agricultural land may be is destroyed and rivers may be rerouted. Where factories are washed away and infrastructure is damaged, people may begin migrating out. In poor countries there is inevitably not enough money to fix everything.
The danger from typhoons increases with time as coastal areas become more developed and urban areas sink as result of the drawing of underground water. Global warming is predicted to raise sea levels, making the situation even more dire.
There are examples of typhoons and hurricanes striking certain areas and dramatically altering the coastline. Barrier island are particularly vulnerable, there are cases of such island that were formed thousands if years ago that have been whittled down to islets and remnants in 150 years by storms, subsiding land and rising sea levels.
Areas Hit by Typhoons
Most typhoons usually track north and first strike places like Guam, Saipan, Taiwan and Okinawa and then either move northward into Japan or Korea or move westward into the Philippines, Vietnam, or China. Because the Caroline Islands of Micronesia are breeding grounds for typhoons they rarely get hit by fully developed storms. Typhoons usually pass north of Palau.
The island of Okinawa lies right in the heart of Typhoon alley. The islands there get hit by an average of seven storms a year, some of them with winds exceeding 190 miles per hour. in the old days, fisherman's families there kept their finances in the name of the wife because fisherman often went out to sea and didn't come back.
Stronger and More Frequent Typhoons?
from a typhoon in 1939 Some climatologists believe that the surge in the number of typhoons and hurricanes in recent years may be linked to global warming which warms up the seas and provides more energy for weather phenomena that develop into severe storms. In 1995, there were unusually high number of hurricanes. Coincidently or not, 1995 also had the highest global surface temperatures on record. and ocean temperatures in the Atlantic were the highest ever recorded. In one of the 11 years between 1995 and 2005 there were unusually high numbers of hurricanes.
There are generally more major hurricanes in years when the sea surface temperatures are higher than average. Sea temperatures in the Atlantic Ocean rose steadily from 2000 to 2004, and each of these years had an “above normal” hurricane season with the exception of 2002 which was a weak El Nino year. But the Atlantic patterns fluctuates and are not consistent. The mid 1920s through the 1960s were very active when temperatures were relatively cool. The 1970s and the early 1990s were quiet.
There was a particularly high number of typhoons in 2004. By August of that year there had already been nineteen, 35 percent more than normal. Ocean temperatures in 2004 were around two degrees F higher than normal. The year 2005 was a bad year for hurricanes. There were 27 named tropical storms—including Katrina, which killed more than 1,000 people and lef much of New Orelans and the neigboring coast in ruins—so many the list of storm names was extended with Greek letters. There were a record 15 hurricanes, including foru category 5 storms.
Typhoon Bilis Super typhoons stronger than Hurricane Katrina that devastated New Orleans are expected to hit the Asia-Pacific region over the coming decades with global warming being one of the causes. Some scientist have suggested that global warming will increase the rain fall from typhoons by 20 percent and increase their winds by 10 percent. Damages is also worsening because more intense typhoons are coinciding with rising seas levels. But not all the damage is the fault of the storms. Damage typhoons is also increasing because more people than ever live on coastlines or other vulnerable areas.
To study storm intensity, scientists use models that reduce storms to grid of points and study how these points interact. The smallest resolution for a point on these models is about one square kilometer. Most are about a hundred square kilometers. Thus far these models have proved to be poor predictors of intensity because the features that cause storms to gain and lose intensity are often smaller than a square kilometer.
To gain insight into typhoon and hurricane dynamics, scientists are studying how moist and dry air affect the eyewall; looking closely at the eye itself and the vortexes that sometimes form there; and setting up wind detectors on the ground in places were storms hit and measure the flow of air as it passes through building or us funneled by mountains and valleys.
Storm intensity used to be predicted solely on the basis of atmospheric conditions. More accurate predication models now feature information on ocean surface temperatures. These days oceans temperatures are studied with probes that no only measure sea temperatures at the surface but also measure currents and temperatures at deeps up to 3000 feet to gain insights into how movements of warm and cool water affect storms.
About a dozen supercomputers around the globe have storm predictor models. There is even a supercomputer in Florida that evaluates all the data from all the supercomputers to see which models are the best predictors and best match reality.
Damage from Typhoon Saomi in August 2006
Close range information on hurricane is gathered by planes that fly over the storms, into the eye of the storm and drop probes called dropsaonders that look like a baton attached to a parachute and measure wind speeds and direction, humidity, heat and pressure as the descend through the storm. They take about 15 minute to descend from 40,000 feet to the sea. Scientist also use airborne devices launched with weather balloons whose movements can be tracked with Global Positioning System (GPS) systems.
American scientists studying hurricanes use NOAA P-3 turboprop planes to fly into the eye of Atlantic hurricanes. They generally only study conditions several thousand feet above the worst turbulence and use dopplar radar to observe the bands of rain as part of the Hurricane Rainband and Intensity Change Experiment (RAINEX). Often times two or three ate flown at the same time to get a big picture view of the storm.
These day robotic aircraft are being used to fly right into the heart of the storm. In 2005, an 28-pound aircraft called the Aerosonder flew into the middle of a tropical storm and stayed there for 10 hours, flying as low as 1,200 feet, measuring wind speeds, moisture content of the air, heat and pressure, and relaying information at a rate of twice a second. One its primary mission was how observe how heat form the ocean was transferred to the storm.
Observing Typhoons with Satellites
Typhoons are photographed from space using weather satellites. Before the existence of these satellites determining where a typhoon was going, where or when it would strike was often speculation at best.
The Tropical Rainfall Measuring Mission (TRMM) satellite was launched in November 1997. It has a unique “rain radar” that probes like a CT scan deep into clouds with microwave, infrared and lightning sensors, allowing scientists accurately see the eye and powerful updrafts to investigate how typhoons and other storms form as well study other things like global warning and the El Nino affect and rainfall patterns around the globe.
One scientist told the Washington Post, “TRMM’s radar can peer inside tropical storms to watch them evolve...A lot of times you’ll see just see a ball of white cloud, but TRMM can go to the core, see the eye wall start to develop: Is it intensifying? Is it getting better defined? Is it falling apart.” TRMM is especially good at detecting fast rising columns of air that act as energy pumps for the whole system.
NASA almost let TRMM satellite fall to earth rather spend the relatively paltry sum of $28 million to keep it aloft, Scientists were outraged that such a valuable tool could be allowed to fall to earth just like that. One of the reasons for the lack of money was a shift funds to Bush’s Mars program. Funding came through at the last minute.
Rain from Typhoon Wipha Typhoons cause much less loss of life than they used, in part because of effective warning system that help people get out of harm’s way. Scientists have gotten good at predicting the track of storms but still have difficulty predicting the damage because they have difficulty determining a storm’s intensity at a given spot and figuring how long it will stay at that spot.
Typhoons are relatively easy to track because they are often directed by high pressure system that move the storm in easy to predict patterns. Storms are generally carried westward from the places they were formed by tropical easterly winds. As they head northward they are more influenced by the jet stream and the prevailing westerly winds. The presence of land and winds in the upper atmosphere going different directions than those on the ground can disrupt the storm itself and make its movements more unpredictable.
Predications are made by gathering data from satellites, models, and other data such as that from aircraft that fly into the eye and plug all this information into several supercomputer storm simulators to get give information on the track, strength and damage. Predications are given in the form of 24 hour, three day and five day projections.
Typhoon Warning System
Typhoons frequently occur in Taiwan, which has its own storm warning system that alerts Taiwanese citizens of impending storms over the TV and radio. The first warnings are a 1) Storm Advisory, which warns a storm could strike within 48 hours; a 2) Sea Warning, which projects a storm will be within 60 miles of the shore within 24 hours; and a 3) Land warning, which projects a storm will hit land within eight hours.
Typhoon Saomi Condition 24: destructive winds can be expected in 24 hours. At this stage Taiwanese are advised to fill their gas tanks, make sure they have plenty of flashlight batteries and candles and put away loose boards or other items that can be picked up by the wind and injure people.
Condition 12: destructive winds can hit within 6 hours. At this time Taiwanese are told to move valuables upstairs, and fill the bathtub and containers with water.
Condition 6: destructive winds can hit within 3 hours. Taiwanese are told to turn up refrigerator to maximum cold and try not to open it; unplug nonessential appliances; stay indoors; use the phone only for emergencies; do not travel; and tape large windows that might be exposed to heavy winds.
Emergency Alert: Destructive winds and rain are occurring over the island. Stay indoors, move furniture away from the windows, roll up rugs and place them on furniture if there is a possibility of flooding. If power goes out use refrigerator as little as possible.
Some scientists say the best place to seek shelter in a storm is a concrete parking garage which is unlikely to collapse because it solidly built and winds blow through it rather than push on it. Moreover the winds that blow through it subside once they are inside the structure
Storm modification ideas once regarded as kooky but now being given serious thought include: 1) using large ship-based fans on a ship centered in the eye to break up the inner wall ofa the storm and make it implode; 2) sprinkling the eyewall with rain-inducing silver iodine to cause convection and make the eyewall expand, weakening it; and 3) shooting heat-absorbing carbon (soot) into eyewall to change the distribution of heat, also weakening it.
Studying Typhoons in Japan
Typhoon Durian in
December 2006 Typhoons and hurricanes are watched with satellites in geostationary orbit 22,000 miles above the earth; reconnaissance aircraft that fly into the heart of storms to collect data on winds, humidity and pressure; Doppler weather radar that gives details on wind changes with scans that occur once every six minutes; and computer models that take in all the various data and predict directions, times, rainfall amounts and flooding.
Wind predictions are still inaccurate. In 2005, the average error was 23 mph, the same as in 1970. Observations have been made of typhoons that have struck Japan using American WC-130 aircrafts that have taken off from American bases in Japan and Guam. Japan has not conducted many of these kinds of observations because of the high cost of running the missions.
The Japanese Meteorological Agency plans to study typhoons by dropping observation devises with small parachutes from a plane into a storm. The devises, which measure wind direction, pressure and temperature and other conditions, are not dropped into the eye but rather into areas of intense wind activity.
There has been some discussion of using weather modification techniques to reduce the power and change the course of typhoons and hurricanes. One scheme calls the harnessing an army of planes to drop soot on the top of the clouds to lower their temperature. Ideas such as cloud-seeding storms with silver dioxide that were dismissed as ineffective in the 1960s have drawn interest in recent years as the understanding of storms has increased to a point where perhaps a pinpoint strike on part of the storm vital to its strength might work to weaken or modify it.
Image Sources: Typhoon News weblog, NASA, Wiki Commons
Text Sources: New York Times, Washington Post, Los Angeles Times, Daily Yomiuri, Times of London, Japan National Tourist Organization (JNTO), National Geographic, The New Yorker, Time, Newsweek, Reuters, AP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
© 2009 Jeffrey Hays
Last updated March 2010