Precise Weather Models Guide Navy's War Planning.
Technologies that can predict weather conditions with a high degree of precision are valued tools for U.S. military commanders as they prepare for war.
The Navy's involvement in predicting weather for all U.S. military forces is integral to the Defense Department's war planning work, because awareness of weather conditions is necessary to fight today's wars, said Richard Spinrad, technical director for the Oceanographer of the Navy.
"Fighting without a knowledge of the weather is like fighting with no maps of the terrain," said Cmdr. David Titley, a Navy meteorologist assigned to the office of the assistant secretary of the Navy for research, development and acquisition.
"The side that can best anticipate and exploit changes in the weather creates a significant advantage for itself," said Paul Schneider, principal deputy assistant secretary of the Navy for research, development and acquisition. "As it has been said many times before, we are not interested in a fair fight. We seek all possible advantages for our combat troops," he said.
The Fleet Numerical Meteorology and Oceanography Center (FNMOC), based in Monterey, Calif., and the office of the oceanographer, based at the Naval Observatory in Washington, D.C., work in tandem to forecast weather for the fleet. While FNMOC's 300 employees engage in "operational processing," collecting weather data from sources all over the world and plugging the data into models, the oceanographer's office manipulates the information to find patterns, maintains historical records and develops program initiatives. The oceanographer's office is the program sponsor for FNMOC, as well as for the Naval Meteorological and Oceanographic Command (METOC) in Bay St. Louis, Miss.
FNMOC processes weather information by using sophisticated modular supercomputers. Because they are modular, the entire system does not go down when one module breaks. The computer has the capacity to work around a broken module until it can be replaced. Much of the data collected from the supercomputers also is sent simultaneously to another of FNMOC's customers, the Commerce Department's National Weather Service, which provides weather information to the public. FNMOC also hosts an unclassified free Web site, accessible through http://www.fnmoc.navy.mil. According to Spinrad, the Navy's increasing Web presence is part of the concept of a "net-centric Navy."
"Weather models have been deemed a strategic national asset by the federal government," said Bob Bishop, chairman and chief executive officer of SGI Federal, the company that makes the modular supercomputers used by the Navy to collect weather data. "Weather affects everyone," he said. "The travel, aviation, sports, recreation and military industries" all have business to conduct that is either successful or not, depending on the nature of the weather, said Bishop. In fact, Bishop reported, earlier this year, the Navy and another of SGI Federal's customers, The Weather Channel, signed a memorandum of understanding to engage in professional collaboration. The Weather Channel is reportedly interested in generating the same kinds of weather models created by FNMOC, which "utilize the largest existing, real-time databases of oceanic and atmospheric operations," Bishop said.
Weather models fill in the gaps of time and space, said Titley. "We need to be able to put the data that we collect together into a coherent package, and the way we do that is to use the model to step forward in time and space and forecast the weather.
"So I can go to any point (on the weather model), be it the Persian Gulf, the central Pacific or New York City, and I can tell what the forecast will be," said Titley.
The supercomputers are located at FNMOC headquarters, in Monterey. "We receive data from sources all around the world. From ships, satellites, buoys, aircraft and land stations, we are continually receiving data, and we assimilate that data into our models," said Mike Clancy, chief scientist and deputy director of FNMOC. Eight Navy military survey vessels, one P-3 aircraft, several mobile survey teams, unmanned aerial vehicles and unmanned underwater vehicles are used to collect the data. Also, cooperative agreements with other countries allow the Navy to glean additional information, said Spinrad.
Two models are run by the supercomputers that are available to the fleet at all times. A global model, which provides up-to-the-minute reports of weather conditions anywhere on the face of the earth, is called the Navy Operational Global Atmospheric Prediction System (NOGAPS). The Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) is a regional model that covers selected parts of the world and can be run at a higher spatial resolution to provide a more detailed prediction of the weather. "We focus the COAMPS model runs in areas of high Defense Department interest, which are often coastal areas," said Clancy.
"This reflects the fact that the Navy in the post-Cold War world, has many of its operations in coastal areas, whereas during the Cold War, the main Navy mission was to take on the Soviet fleet in the open ocean," Clancy explained.
Sailors are able to access weather conditions by logging on to the oceanographer's Web site or the master environmental library, a military-only site managed by the oceanographer's office. They also can request specific regional information from the oceanographer's staff. Also, when a vessel enters a particular region, the oceanographer's office tracks its progress, and alerts shipboard personnel if any weather conditions could affect its course, according to Ed Weitzner, manager of modeling and simulation environmental support policy for the oceanographer.
Weather's Effects an Weapons
Part of Schneider's duties as deputy assistant secretary of the Navy for research, development and acquisition is to recommend which tools must be acquired to maintain and improve the Navy's forecasting capabilities. "We are sensitive to the effects that clouds, high winds, rain, snow and cold temperatures have on both weapons and the personnel who function in those environments," he said.
According to Spinrad, "we have the capability to forecast high-resolution images of winds and precipitation," he said. This is a critical capability for planning air strikes. For example, "the modern battlefield is very much dominated by precision-guided munitions, such as laser-guided weapons. Lasers are sensitive to things like clouds and aerosols, like smoke and dust," Clancy said.
"In the case of cruise missiles, if they're encountering a severe headwind, they might not be able to make it to the target. Or a high temperature might also make it difficult to reach the target," he said. The wind also affects the safety of such operations as in-flight refueling, and knowing what the weather conditions will be helps officials to determine whether to schedule aircraft sorties, Clancy said.
For example, Clancy explained, the Dday invasion of Notmandy, during World War II, was planned for a particular day, partially because of optimal weather conditions. "Weather was a significant issue, as well as the size of the ocean waves. The weather was a big factor in the go/no-go decision-making process to launch the attack that day," he said. The failed Iranian hostage-rescue mission during the Catter administration, Clancy related, was, complicated by "a severe sandstorm impeding helicopter operations," he said.
More recently during the Gulf War, "the weather over the target was clearly an issue, particularly the amount of cloud cover, and there were lots of instances where aircraft were not able to use their precision-guided weapons because of restricted visibility." Clancy said. "One might decide not to launch a strike on a particular day because the ceiling (cloud cover) could be too low," he said.
The Defense Department has a long history of trying to understand and predict the weather and the conditions of the ocean. "We want to be able to pick the weather to fight in," said Clancy.
However, the ability to predict the weather is not foolproof, according to Titley. "The chaos in the atmosphere limits the capability of predicting everything. But from a military perspective, if I could tell a commander what the weather would he like for the next 12-15 days, that would influence not only the specific tactics that he would take, but would also impact the operation as a whole. If I knew I had a 'weather window' of opportunity, that could potentially impact when the commander would conduct an operation," Titley said.
There is a certain amount of human guessing that must be used to determine that weather window, to fill in the gaps of the models. "A model by definition, does not incorporate every scale that's in the real atmosphere," Titley said. "It's pretty good, but like any model, there are some assumptions and simplifications that have to be made. That's one of the reasons we have people employed as meteorologists, because if the models were perfect, we wouldn't need them."
The weather affects the jet stream of the ocean, and knowledge about specific conditions involving the water and the ocean floor can affect the performance of shipboard electronics, said Weitzner. "There are highs and lows in the atmosphere of the oceans, and conditions such as twirling water can create phenomena such as a slow-moving cyclone. Transmission ability can become limited if this creates a muddy ocean bottom," he said. However, currents can also act as an effective acoustic block, so if you know where the front of the weather current is, you can hide behind it and not be detected (by an enemy)," he said.
The undersea sounds can sometimes be loud, and this can influence ships' sensors such as sonar. "If the ocean is noisy, it's like you are in a shower, and you can't hear anything outside the shower." Whether the ocean bottom is muddy also can affect the noise levels inside the ocean. "Sounds can bounce off the bottom," but if the bottom is muddy, noise is simply absorbed, Weitzner said.
Titley explained that since there are so many factors that go into predicting the wather, it is impossible to forecast with 100 percent success. "The weather keeps changing, and that's why we have to keep paying attention to it," he said.
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|Author:||Book, Elizabeth G.|
|Date:||Nov 1, 2001|
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