While the federal government operates several hundred full- and part-time weather stations in the United States, given the size of the nation, many more stations are needed to fully define our weather and climate. The number of points is greatly expanded by the nation’s team of cooperative weather observers. These volunteers take vital temperature, rainfall, and snow fall measurements on a daily basis at almost 10,000 sites across the nation. Their instruments are checked by the National Weather Service. Over five million cooperative reports are collected and assembled each year at the National Climatic Data Center.
Many of these cooperative stations remain within the same families for generations. Colorado has eleven cooperative weather observer stations that have been in operation for 100 years or more. Such continuous strings of weather data taken in the same placed are invaluable in assessing whether or not global and regional climate is in fact changing with time. The earliest known such weather records in America were kept by a clergyman at Swedes’ Fort, near Wilmington, Delaware, in 1644 and 1645.
Weather observing is a major hobby in the United States. Two publications that would be of interest to hobbyists are the American Weather Observer (401 Whitney Blvd, Belvidere, Illinois, 61008-3772; 815/544-9811; awowx@aol.com) and Weather-wise magazine (published by Heldreff Publishers, Washington, D.C.; call 1-800-365-9753 to place a subscription).

Many scientists with training in physics work on atmospheric-related problems. These can include issues related to radar and radio wave propagation, optical propagation, acoustics and spectroscopy, to name just a few. The field can be highly theoretical and mathematical. There are also many observationally oriented programs in which new sensing systems are developed such as Doppler lidar, radar, and acoustic profiler and satellite sounding systems.

Atmospheric chemistry is a scientific discipline that deals with the chemical constituents in our air. The problems addressed, often at a very highly theoretical level, include understanding and predicting stratospheric ozone levels, which are now known to be strongly influenced by chemicals injected into the atmosphere by humans. Closer to the ground, unraveling the problem of regional smog has remained a major challenge. The fate of many chemicals released into the atmosphere and their interactions with ecosystems is under close study. The emissions of natural pollutants from trees, soil micro-organism, and geological processes is vital to understanding global chemical balances. There are now more than 10 million manufactured chemicals that have been identified. Many of them are released into the atmosphere with as yet unknown consequences.

Weather is responsible for 85 percent of the U.S. areas declared a natural disaster area by the President. The average annual direct damage toll due to natural disasters in the United States has been running at about $6 billion. In recent years the toll has been much higher, such as 1989’s $15+ billion and 1992’s $30+ billion. While natural disasters usually cannot be prevented, adequate planning and timely warnings can greatly reduce the loss in human lives and property.
Federal, state, and local governments coordinate the distribution and response to weather warnings. The planning of evacuation routes and shelter locations in hurricane zones is one example. Conducting community awareness programs in flood and tornado-prone regions and upgrading building codes to make buildings less prone to wind failure are current activities. Dispersion meteorologists routinely simulate in computers the consequences of hypothetical accidents at nuclear and chemical plants so that the impact of any real accident can be greatly minimized.

The forensic meteorologist, who may act as either a background consultant or an actual testifying expert, will collect, interpret, and analyze atmospheric data in sup port of insurance fraud claim investigations, civil and criminal trials, and environ mental regulatory actions. The forensic meteorologist may be employed directly by an insurance company, the attorneys for either the plaintiff or defendant in a case, or, with increasing frequency, may be appointed by the court itself. Regardless of the employing party, it is not the role of the meteorologist to be an advocate for either side in a dispute, but to assist the judge and/or jury in understanding the often complex facts in a case so that they may reach an appropriate verdict.
Some typical problems dealt with in forensic meteorology include the following:
An automobile accident was caused by poor visibility—was that from a natural fog or pollutants from a nearby industrial plant? Was the building damaged by a tornado or a straight line thunderstorm wind? A person was found dead near a downed power line—was it a fault in the utilities’ line or a lightning strike? How can we demonstrate that rain fell at a site that is located many miles distant from any National Weather Service reporting station?
The forensic meteorologist may collect standard weather observations, assemble weather radar and satellite imagery, process weather data taken by a party in the case, or locate non-standard sources of data such as lightning ground stroke reports or atmospheric data taken by air pollution monitoring networks. These data are then used in a comprehensive analysis of the meteorological facts pertinent to a case. There is increasing use of sophisticated computer graphics and video animation of weather information in trials and administrative hearings. Most forensic meteorologists have had long and varied careers in the atmospheric sciences, and it is their hard-earned expertise that is in demand. Few recent graduates can expect to be heavily engaged in such activities until they have significantly enhanced their resumes. Most successful forensic meteorologists have met the qualifications of Certified Consulting Meteorologist (CCM).

On 7 November 1940, brisk winds of 30 - 35 mph caused the structure of the Narrows Bridge in Tacoma, Washington, to vibrate so excessively, the entire structure collapsed into the water. And “Galloping Gertie,” as the span was dubbed, entered the engineering Hall of Shame. But it also gave impetus to a field that could be called wind engineering. Meteorologists must work with structural and civil engineers when high-rise buildings, sports stadiums, bridges, and other large structures are designed and built. The failure to properly account for the characteristics of the wind in a given area can be a costly mistake. Also, the “wind proofing” of even ordinary homes can potentially save billions of dollars when the next major hurricane slams ashore.
 

This computer simulation of the dispersion by winds of hypothetical radioactive pollutants released from a nuclear power plant was created for emergency response planning and evacuation studies.
  

Meteorologists can apply their skills to the operation of nuclear generating stations such as this one on the Lake Michigan shoreline.

When weather forecasts can be used in conjunction with commodities trading, some significant profits can be generated (losses can be whopping, too). Three days’ notice of a killing freeze in the Florida citrus belt can be the signal to buy orange juice futures. An overnight rain in the parched soybean belt can drive prices down quickly. Advance knowledge of the rainfall can prompt a profitable sale before prices collapse. In many ways this type of weather prediction deals with the complex connectedness of things in nature. How did a cool spell in Wisconsin in July 1994 affect the price of your Thanksgiving cranberries? Turns out the chilly mid-summer weather in the Wisconsin cranberry bogs hampered the pollination of the berries by the local bees. And while the final berry yield was 1.6 million tons, it was below a good year’s output. Sup ply and demand takes over, and your Thanksgiving condiment goes up in price.
It was wet, then it was warm in Iowa in February 1992. The result? Mud. So much mud that school buses got bogged down, some schools even closed, and hogs couldn’t be brought to market. Cattle had trouble putting on weight as they were working so hard carrying around all that mud. But commodities traders who know about potential problems like this before the rest of the market catches on can use it to their economic advantage.

How much does a bad winter cost the U.S. economy? The harsh winter of 1976-77 was estimated to cause $37 billion in direct economic losses due to lost retail sales, increased energy consumption, difficulties in transportation and industrial production, and crop losses. Advanced warning can help reduce some of these losses. Cold weather, for instance, affects heating bills, thermal underwear sales, shipping—and video rentals. In many cities, video rentals have been known to double on weekends when the weather is exceptionally cold. Cold weather also means hot pizza. One Twin Cities pizza delivery establishment found that when it was bitterly cold, even normally hardy Minnesotans would rather someone else get the frostbite—his sales increased $400—500 on very cold evenings. Knowing that in advance means bringing in more help to meet demand. Baseball teams hire private forecasters to predict the beginning and end of rain to help the ground crews decide when to put on the tarps. On a larger scale, knowing that the temperature will jump 10°F in New York City on a summer day allows an electrical utility to purchase the needed extra power before the demand soars and the prices of power go up with it. The correct forecast of a few degree temperature rise or fall can save an electric company millions of dollars. Precipitation pre dictions for mountain reservoirs and drainage basins assist utility managers in planning hydroelectric power generation. Forecasts of temperature for snow making at a ski resort, rainfall on an outdoor movie set, relative humidity for a proscribed agricultural burn, and winds for a hot-air balloon rally are just a few of the many forecasts made for industry by the private weather forecasting firms in the United States.

Meteorologists have played a central role in much of the air quality research and control efforts in the United States over the past several decades. Atmospheric conditions play a key role in predicting the diffusion and transport (collectively called dispersion) of pollutants. If a new power plant is to be built, it is necessary to know the impact of the pollutants that it will release. Since one can’t measure pollution concentrations before the plant is built, numerical models of pollution dispersion simulate the atmosphere’s influence upon the plume once it leaves the proposed smoke stack. In an effort to control regional ozone, meteorologists work with chemists to create numerical “photochemical grid models” in which the known pollutant emissions are used to predict the ozone levels. Once these models are verified, then one can predict the consequences of planned emission controls, such as cutting automobile hydrocarbon emissions by 10 percent or power plant oxides of nitrogen releases by 30 percent. The complex models are necessary because the actual results of such controls can often be quite different from what might be expected.

Crops are clearly sensitive to weather. And sometimes something can be done about it. Knowing that the next few days will be rain-free can prompt a farmer to make hay while the sun is shining, and thus maximize the yield. Forecasts of winds can assist in aerial application of chemicals while avoiding herbicide drift onto a neighbor’s tomato field or organically grown fruit. Frost and freeze forecasts can be a call to action to fire up smudge pots, turn on wind machines or water sprinkling systems in the citrus groves. Cold, low lying spots in Wisconsin can have frost even during summer. Cranberries growing in the shallow bogs can be protected by flooding the field. The application of agricultural chemicals as well as irrigation water can be timed much more precisely and economically by monitoring past weather and matching it to predicted conditions.