NOAA's arc
Think of the North Pole. It's where Santa lives. It's very cold. The South Pole is pretty cold, too. Remember the pictures of Sir Earnest Henry Shackleton on his expedition to the South Pole? It looked very cold.
Now think of the equator. Think of India, South China, North Africa, Central America, Jamaica, and Hawaii. Those places are hot. They're hot all the time. These are places you want to avoid if you sell wool jackets.
So let's imagine that the poles of the earth are sources of cold air, and the equator is the source of hot air. Let's imagine that these sources constantly spit hot and cold air up into the atmosphere, blanketing the planet from the top, bottom, and middle. When the cold air hits the hot air, we get storms.
Of course, most of the planet is water, so many storms happen over the oceans. When a storm happens over the ocean, winds blow on the surface of the water and create chop. Light wind produces small chop, but heavy storm winds produce big and ugly chop. Think of pirate movies, where the boat rocks precariously from side to side. Water splashes onto the deck. The first mate cries, "Aye captain, she's a-blowin' us o'er." Now, that's some real chop. Each piece of chop is a small wave. It has a height, a speed, and a direction. (The direction is the same as the wind that made it.)
When the storm dies, the individual waves of chop either die or keep moving. Those that were small and slow, and didn't have a lot of energy, fade into the water and die. But, those pieces of chop that picked up enough power during the storm keep moving. Picture a vast army of chop marching away from a storm event. As they travel, they organize. Smaller waves are overcome by bigger waves and their energy is absorbed. Waves at similar speeds group together. When enough chop travels away from a storm, and has travel time to organize into neat and clean groups of wave sets, we call that a swell.
Swells move across the ocean in a funny manner, known as deep wave propagation. A group of waves moves together. Big waves are in the middle. Smaller waves are in front and behind. But, each individual wave in the group moves faster than the group as a whole. A small wave rises up in the back of the group, becomes larger as it gets to the center of the group, then shrinks as it moves to the front of the group. When the wave reaches the front of the group, it disappears, and reappears in the back.
Why waves like to travel this way is a topic of discussion for physicists. I read a few theories, but I couldn't understand any of them. Personally, I think it's neat. I'm trying to convince my wife to try this with the family on walks through the park. All three of us could lie on the grass. The one in the back could pop up and crawl over the other two, then lay down in the front. The next one pops up, crawls over, lies down, pops up, crawls over, and lies down. We'd be the hit of the park, that's for sure.
"What the hell are you guys doing?"
"Deep water wave propagation."
Fascinating as it is, deep-water wave propagation doesn't have anything to do with surfing. We surf in shallow waters. So shallow, in fact, that the depth of the wave is less than the depth of the water. The bottom is pushed up over the top and the wave breaks.
Not many surfers care much about deep-water propagation directly. They do, however, care about people who care about deep-water propagation. That is, they care about surf forecasters.
Surf forecasting has grown more in the last thirty years than at any time in history. Surfers who listened to coastal radio broadcasts for ocean buoy data can now view real time color charts of wave height, period, and swell direction on their computer screen with the click of a mouse. Surf forecasters can accurately predict the arrival of swells and which beaches will get the best surf. A surfer today has resources to know what to expect at which beaches every day.
Since I started surfing in the mid 1990s, I have never known a time when reasonably reliable surf forecasts and accurate real time surf reports were not available to me.
Real time surf condition information is provided by buoys. Buoys are great devices. They sit in the ocean and they bob up and down. But they measure every movement. Those movements are processed into swell conditions: amplitude (wave height) period (time between waves), and direction. Since the dawn of the Internet, buoy data is easily available to anyone interested. Data from the buoys is updated hourly, or every three hours, depending on the buoy. CDIP, the Costal Data Information Program, has 14 buoys located along the coast of Southern California, from Point Conception to San Diego. NOAA, the National Oceanic and Atmospheric Administration, operates 7 buoys in the same region.
The Internet site for CDIP provides a color graph of wave heights along the entire California coast based on buoy data fed through computer models of the California coastline. The chart includes primary swell direction and period, and is updated with every polling of the buoys. The chart is called the "nowcast". I checked this website every morning from a computer next to the breakfast table in my dining room. The buoys updated at 3:40 a.m., giving me a good picture of the swell conditions only two hours before I would set foot in the water.
But, buoy data can only provide a snapshot of the present. To see the future, we look to NOAA. NOAA is pronounced Noah, like the man in the Hebrew Torah whom God warns about a coming storm. With this information, Noah was able to build a boat for his family and a few pets.
NOAA collects and distributes data from a vast satellite network above the globe. Weather monitor satellites fall into two general categories. Geo-synchronous satellites orbit the earth at the same speed of the earth's rotation, which fixes them above a position on the earth. The GEOS-8 and GEOS-10 satellites, for example, sit over the north and South Pacific Ocean. (GOES stands for Geostationary Operational Environmental Satellite). Geo-synchronous satellites take three types of pictures, visible images (VI), infrared imagery (IR) and water vapor imagery (WV), to determine cloud and storm patterns in the atmosphere. This data is extremely useful, but its value is increased when combined with the information from the polar orbit satellites, which spin over the north and south poles twice per day. POSIDON/TOPEX, ERS-2 and SSM/I are polar orbit satellites. They orbit at a lower altitude than geo-synchronous satellites, and enable observations of wave and sea heights and near-surface wind conditions. Then, of course, there is QuickSCAT. Launched in 1999, the QuicSCAT satellite observes over 90% of the planet's oceans every 24 hours. Using microwave radar, QuickSCAT measures surface wind speed and direction with an accuracy previously unimagined under nearly any weather condition.
In other words, when and where the wind blows, NOAA knows.
NOAA is a division of the US Department of Commerce. It employees 12,000 people, and operates on an annual budget of $3.2 billion. Its scope of services is too long to list. Suffice to say that the website at www.noaa.gov is the doorway to an incredible library of nautical, marine, atmospheric, costal, and satellite information.
One of the programs funded by NOAA (as well as the US National Weather Service, and the US National Center for Environmental Prediction) is called "Wavewatch III". Produced for predicting hazardous costal and nautical wave conditions, Wavewatch III is a global model of open ocean wave height, period, and direction. The model produces forecasts up to 108 hours. In other words, with the click of a mouse, surfers can see the size, direction, and energy of every swell, produced by every storm everywhere on the planet's surface.
Truly, this is the age of information.
North shore surfers from the beach boy generation tell stories about dropping everything to go surfing when the waves were good. One could never tell if the waves would be good or not, so one had to be ready to live at a moment’s notice. Surfers brushed aside family, jobs, friends, and obligations without even so much as a word of warning when the big swells came in.
I know a few days in advance.
Sources
www.stormsurf.com is the site that I read to understand waves. Most of this article is condensed from Stormsurf's pages. There are a bunch of tutorials on the site that are well worth reading for any surfer.
http://www.noaanews.noaa.gov/stories2004/s2356.htm
Underwater, underfunded: NOAA faces Budget Cuts, Amanda Onion, ABC News (accessed at http://www.cdnn.info/industry/i040322b/i040322b.html on 12/22/04)
www.noaa.gov
http://polar.ncep.noaa.gov/waves/
What isn't in this article is my opinion of the "pay for forecast" services (not to mention any names) that bleed US taxpayers for $20 a month for access to information that their government already paid hundreds and million of dollars for.
If these guys are scientists, and are moving the state of forecasting forward, then they should join NOAA, get some grant money, and give us all something that everyone can use. If they are, on the other hand, serving the industry, so that credit card, cell phone, and surfwear companies can have pictures of tow in surfers on big waves, then they should get the support of those industries that profit from it.
There may have been a time when this was appropriate, when the wealth of real time and predictive information wasn't as available and needed an interpretation and delivery service for surfers. But, that time is passed. The "pay for forecast" business in the US today is, in my opinion, unethical. It's a scam. Don't fall for it.
I get my info from www.stormsurf.com. He updates five-day predictions twice a week for the west coast, and does it for free. www.surfingsandiego.com also has a good little section on forecasts, which points back to Wavewatch III. The official wavewatch III portal is at http://polar.ncep.noaa.gov/waves/main_int.html
Copyright 2004 Travis R. English
Now think of the equator. Think of India, South China, North Africa, Central America, Jamaica, and Hawaii. Those places are hot. They're hot all the time. These are places you want to avoid if you sell wool jackets.
So let's imagine that the poles of the earth are sources of cold air, and the equator is the source of hot air. Let's imagine that these sources constantly spit hot and cold air up into the atmosphere, blanketing the planet from the top, bottom, and middle. When the cold air hits the hot air, we get storms.
Of course, most of the planet is water, so many storms happen over the oceans. When a storm happens over the ocean, winds blow on the surface of the water and create chop. Light wind produces small chop, but heavy storm winds produce big and ugly chop. Think of pirate movies, where the boat rocks precariously from side to side. Water splashes onto the deck. The first mate cries, "Aye captain, she's a-blowin' us o'er." Now, that's some real chop. Each piece of chop is a small wave. It has a height, a speed, and a direction. (The direction is the same as the wind that made it.)
When the storm dies, the individual waves of chop either die or keep moving. Those that were small and slow, and didn't have a lot of energy, fade into the water and die. But, those pieces of chop that picked up enough power during the storm keep moving. Picture a vast army of chop marching away from a storm event. As they travel, they organize. Smaller waves are overcome by bigger waves and their energy is absorbed. Waves at similar speeds group together. When enough chop travels away from a storm, and has travel time to organize into neat and clean groups of wave sets, we call that a swell.
Swells move across the ocean in a funny manner, known as deep wave propagation. A group of waves moves together. Big waves are in the middle. Smaller waves are in front and behind. But, each individual wave in the group moves faster than the group as a whole. A small wave rises up in the back of the group, becomes larger as it gets to the center of the group, then shrinks as it moves to the front of the group. When the wave reaches the front of the group, it disappears, and reappears in the back.
Why waves like to travel this way is a topic of discussion for physicists. I read a few theories, but I couldn't understand any of them. Personally, I think it's neat. I'm trying to convince my wife to try this with the family on walks through the park. All three of us could lie on the grass. The one in the back could pop up and crawl over the other two, then lay down in the front. The next one pops up, crawls over, lies down, pops up, crawls over, and lies down. We'd be the hit of the park, that's for sure.
"What the hell are you guys doing?"
"Deep water wave propagation."
Fascinating as it is, deep-water wave propagation doesn't have anything to do with surfing. We surf in shallow waters. So shallow, in fact, that the depth of the wave is less than the depth of the water. The bottom is pushed up over the top and the wave breaks.
Not many surfers care much about deep-water propagation directly. They do, however, care about people who care about deep-water propagation. That is, they care about surf forecasters.
Surf forecasting has grown more in the last thirty years than at any time in history. Surfers who listened to coastal radio broadcasts for ocean buoy data can now view real time color charts of wave height, period, and swell direction on their computer screen with the click of a mouse. Surf forecasters can accurately predict the arrival of swells and which beaches will get the best surf. A surfer today has resources to know what to expect at which beaches every day.
Since I started surfing in the mid 1990s, I have never known a time when reasonably reliable surf forecasts and accurate real time surf reports were not available to me.
Real time surf condition information is provided by buoys. Buoys are great devices. They sit in the ocean and they bob up and down. But they measure every movement. Those movements are processed into swell conditions: amplitude (wave height) period (time between waves), and direction. Since the dawn of the Internet, buoy data is easily available to anyone interested. Data from the buoys is updated hourly, or every three hours, depending on the buoy. CDIP, the Costal Data Information Program, has 14 buoys located along the coast of Southern California, from Point Conception to San Diego. NOAA, the National Oceanic and Atmospheric Administration, operates 7 buoys in the same region.
The Internet site for CDIP provides a color graph of wave heights along the entire California coast based on buoy data fed through computer models of the California coastline. The chart includes primary swell direction and period, and is updated with every polling of the buoys. The chart is called the "nowcast". I checked this website every morning from a computer next to the breakfast table in my dining room. The buoys updated at 3:40 a.m., giving me a good picture of the swell conditions only two hours before I would set foot in the water.
But, buoy data can only provide a snapshot of the present. To see the future, we look to NOAA. NOAA is pronounced Noah, like the man in the Hebrew Torah whom God warns about a coming storm. With this information, Noah was able to build a boat for his family and a few pets.
NOAA collects and distributes data from a vast satellite network above the globe. Weather monitor satellites fall into two general categories. Geo-synchronous satellites orbit the earth at the same speed of the earth's rotation, which fixes them above a position on the earth. The GEOS-8 and GEOS-10 satellites, for example, sit over the north and South Pacific Ocean. (GOES stands for Geostationary Operational Environmental Satellite). Geo-synchronous satellites take three types of pictures, visible images (VI), infrared imagery (IR) and water vapor imagery (WV), to determine cloud and storm patterns in the atmosphere. This data is extremely useful, but its value is increased when combined with the information from the polar orbit satellites, which spin over the north and south poles twice per day. POSIDON/TOPEX, ERS-2 and SSM/I are polar orbit satellites. They orbit at a lower altitude than geo-synchronous satellites, and enable observations of wave and sea heights and near-surface wind conditions. Then, of course, there is QuickSCAT. Launched in 1999, the QuicSCAT satellite observes over 90% of the planet's oceans every 24 hours. Using microwave radar, QuickSCAT measures surface wind speed and direction with an accuracy previously unimagined under nearly any weather condition.
In other words, when and where the wind blows, NOAA knows.
NOAA is a division of the US Department of Commerce. It employees 12,000 people, and operates on an annual budget of $3.2 billion. Its scope of services is too long to list. Suffice to say that the website at www.noaa.gov is the doorway to an incredible library of nautical, marine, atmospheric, costal, and satellite information.
One of the programs funded by NOAA (as well as the US National Weather Service, and the US National Center for Environmental Prediction) is called "Wavewatch III". Produced for predicting hazardous costal and nautical wave conditions, Wavewatch III is a global model of open ocean wave height, period, and direction. The model produces forecasts up to 108 hours. In other words, with the click of a mouse, surfers can see the size, direction, and energy of every swell, produced by every storm everywhere on the planet's surface.
Truly, this is the age of information.
North shore surfers from the beach boy generation tell stories about dropping everything to go surfing when the waves were good. One could never tell if the waves would be good or not, so one had to be ready to live at a moment’s notice. Surfers brushed aside family, jobs, friends, and obligations without even so much as a word of warning when the big swells came in.
I know a few days in advance.
Sources
www.stormsurf.com is the site that I read to understand waves. Most of this article is condensed from Stormsurf's pages. There are a bunch of tutorials on the site that are well worth reading for any surfer.
http://www.noaanews.noaa.gov/stories2004/s2356.htm
Underwater, underfunded: NOAA faces Budget Cuts, Amanda Onion, ABC News (accessed at http://www.cdnn.info/industry/i040322b/i040322b.html on 12/22/04)
www.noaa.gov
http://polar.ncep.noaa.gov/waves/
What isn't in this article is my opinion of the "pay for forecast" services (not to mention any names) that bleed US taxpayers for $20 a month for access to information that their government already paid hundreds and million of dollars for.
If these guys are scientists, and are moving the state of forecasting forward, then they should join NOAA, get some grant money, and give us all something that everyone can use. If they are, on the other hand, serving the industry, so that credit card, cell phone, and surfwear companies can have pictures of tow in surfers on big waves, then they should get the support of those industries that profit from it.
There may have been a time when this was appropriate, when the wealth of real time and predictive information wasn't as available and needed an interpretation and delivery service for surfers. But, that time is passed. The "pay for forecast" business in the US today is, in my opinion, unethical. It's a scam. Don't fall for it.
I get my info from www.stormsurf.com. He updates five-day predictions twice a week for the west coast, and does it for free. www.surfingsandiego.com also has a good little section on forecasts, which points back to Wavewatch III. The official wavewatch III portal is at http://polar.ncep.noaa.gov/waves/main_int.html
Copyright 2004 Travis R. English
posted by travinator @ 1:54 PM
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