Chlorofluorocarbons--compounds created only through human activity--have appeared and are also increasing alarmingly. These compounds ultimately interact with other chemicals on the surface of minute ice particles in the Antarctic stratosphere and cause massive reductions in the life-protecting ozone shield there. There is mounting evidence that the global mean surface temperature has increased by approximately 0.5o Celsius over the last 100 years and that the global sea level has risen by 10 to 20 centimeters during this same period.
In 1959, the field of atmospheric sciences was in its infancy. Only two years earlier, the first earth-orbiting satellite, Sputnik I, had been launched, and one year later, the first weather satellite, Television and Infrared Observation Satellite (TIROS) I, would transmit the first pictures of clouds from space. The WSR-57 national weather radar network was just two years old and numerical weather prediction less than ten. The first computer dedicated to the atmospheric sciences, the IBM 1620 located at NCAR, became operational in 1961; it could perform about 1,000 additions per second.
The major research issues of the day revolved around meteorology per se, including, for example, weather prediction, weather modification, and dynamic, physical, and air-pollution meteorology. The range of useful prediction of large-scale weather systems, such as extratropical cyclones, was about two days, and forecasting the occurrence of these systems by computer models had just begun. Little predictive skill existed for smaller-scale, shorter-lived phenomena such as thunderstorms. Knowledge of many mesoscale phenomena was rudimentary, and in routine operations conventional radar was the only tool available for mesoscale observations.
The atmospheric sciences as practiced in 1991 are dramatically advanced from 1959. Sophisticated weather satellites from five different countries and the European Space Agency continuously monitor global weather. Modern Doppler radars, wind profilers, automated surface weather stations, and new sounding systems provide high-resolution, accurate data for research around the world. With the approaching modernization of the National Weather Service, these systems are on the verge of becoming extensively used in operational prediction in the United States. The CRAY Y-MP8/864 at NCAR performs over a billion calculations each second, more than a million times more speed than was available in 1959. Universities and other research laboratories and centers have equivalently powerful computing systems available to and used by the UCAR community.
The range of useful large-scale weather forecasts has increased from two to six days. Fine-mesh regional prediction models, capable of resolving many of the larger mesoscale systems, are in operational use, and very fine mesh mesoscale and cloud models have been developed and used successfully in a variety of research studies. Analysis of data from field and modeling studies conducted during the past decade has greatly expanded knowledge of a wide range of mesoscale phenomena.
The study of climate and the climate system, a relatively minor subdiscipline of meteorology in 1959, has become one of the most intellectually exciting and globally important modern research areas. Climate is now broader than atmospheric sciences, encompassing biology, chemistry, ecology, geology, geography, hydrology, oceanography, solar physics, solid-earth sciences, and elements of the social sciences. Earlier fears of an imminent ice age have been replaced by growing concerns that we may well see, within the lifetime of today's youth, a climate warmer than ever before experienced by human civilization.
The period since UCAR's founding has witnessed a significant, pervasive, and growing recognition that the earth is a complex, coupled system and that atmospheric, biologic, chemical, geologic, hydrologic, oceanic, and human-created components must be studied as a whole. In contrast to 1959, this view is now widespread in the broad scientific and policy communities, and research practices reflect this view more and more. Recognition of the earth as a system and of the profound potential societal and economic impacts of that system on humankind (and vice versa) has led universities to establish multidisciplinary centers, institutes, and degree programs. The same recognition has led industries to participate in global change research as part of their strategic planning for the future. Federal agencies, governments, and nongovernmental organizations around the world are cooperating in innovative ways to plan jointly for research, with the goal of assuring coordinated programs and appropriate levels of support.
At the same time, local and regional severe weather and extreme events continue to harass humankind in all parts of the world. For example, July 1988 was the hottest month on record in the Northern Hemisphere. Nearly 40% of the contiguous United States experienced severe or extreme drought during that summer. In June of that year, the combined flow of the Mississippi, St. Lawrence, and Columbia Rivers was 45% below normal. The United States suffered more than $15 billion in crop losses and between 5,000 and 10,000 deaths attributable to heat stress. In the same year, catastrophic floods in east and south Asia killed 10,000 people; heat waves and droughts in the People's Republic of China, where rainfall was less than 25% of normal, caused 8,000 reservoirs and countless rivers to dry up; and Hurricane Gilbert, the strongest Atlantic hurricane on record, killed more than 200 people and caused massive property damage in Haiti, Jamaica, and Mexico.
Dramatic advances have occurred since 1959 in the observational and computational tools available to attack the complex, interconnected, and intellectually challenging problems that characterize earth systems and weather research. Sophisticated instruments and platforms provide an unprecedented capability to observe the atmosphere, oceans, land surfaces, and the sun. These tools include radars, profilers, satellites, space-based positioning and navigation systems, instrumented aircraft, instruments capable of measuring infinitesimal quantities of gases and particles in the atmosphere, and integrated sensing systems that operate automatically in remote sites. Extraordinarily and increasingly powerful and flexible computers are able to process enormous quantities of diverse data and to simulate the earth system through ever more complete high-resolution numerical models.
The University Corporation for Atmospheric Research was founded to strengthen and extend the atmospheric sciences' capabilities and the resources of the universities and the nation. UCAR, its member universities, and their national center have been at the forefront of improving our fundamental understanding of the atmosphere. The partnership between the universities and UCAR/NCAR has led in developing crucial interdisciplinary links and observational and computing technologies critical to the atmospheric sciences. With such a background, the UCAR community is well placed--and has the responsibility--to play a strong and fundamental role in addressing the complex, interdisciplinary, and international environmental challenges of the 1990s. This document presents a decadal strategy for UCAR to participate in meeting that responsibility.