When Weather Matters Most When Weather Matters Most: timeline In their own words: Richard Reed

UCAR at 40 Who We Are Introduction One Planet, One Atmosphere Between Sun and Earth Measuring and Modeling •When Weather Matters Most Spreading the Word Knowledge for All Looking toward the Future UCAR at a Glance List of acronyms

1960s

1967 • First Foray NCAR manages its first major field program, the Line Islands Experiment. Surface, airborne, and satellite data are gathered from the central equatorial Pacific to study the region's role in global circulation. The project kicks off the 15-year Global Atmospheric Research Program (GARP; see 1974).

1968 • Microscale Motion Research on small-scale air motion leaps forward with data from an internal navigation system that helps aircraft orient themselves in space. Through a nose-mounted probe adapted by Donald Lenschow (NCAR) and Jim Telford (Desert Research Institute), air flow in all directions is measured and correlated to heat, moisture, and other variables.

1972 • Inside Hail The National Hail Research Experiment, based in northeast Colorado, begins five years of work that breaks new ground in observing and understanding thunderstorms. NHRE gathers the first direct evidence of how rain and hail are formed. Randomized cloud-seeding trials do not show any reduction in hailfall due to seeding, a result consistent with new knowledge of hailstorm processes gained from the study. NCAR's ongoing mesoscale and societal impact groups both emerge from NHRE's work.

1974 • GARP's World After years of coordination and planning with many universities and over 70 nations, NCAR participates in the GARP Atlantic Tropical Experiment (GATE), the world's biggest atmospheric field study to date. Exhaustive sampling off the west coast of Africa for GATE yields a better understanding of tropical storm systems and a huge data set still in use 25 years later. In 1979, GARP's Global Weather Experiment provides the worldwide coverage needed to improve computer models of weather and climate.

1981 • High Plains Storms The Cooperative Convective Precipitation Experiment brings some 200 U.S. and European participants to southeast Montana for the largest thunderstorm study ever undertaken. Led by Brant Foote and Charles Knight, CCOPE deploys 14 aircraft, 8 radars, and 130 automated surface weather stations. The coordinated measurements produce key insights into how air is entrained and mixed in clouds and how ice particle growth leads to giant hail in supercell storms.

1982 • Mesoscale Modeling A computer forecast model originally developed at Pennsylvania State University becomes the PSU/NCAR mesoscale model, with NCAR providing remote and on-site support. By the late 1990s, its fifth generation (MM5) has over 600 users at more than 200 institutions worldwide.

1984 • Sailing into Storms In one of a series of related studies, a sailplane operated by NCAR and the National Oceanic and Atmospheric Administration flies in and near New Mexico thunderstorms. The sailplane data challenge earlier ideas of electrical charge distribution within storms, finding negative charge at higher altitudes and more charge on smaller particles than expected.

1985 • Turbulent Ideas A cluster of scientists from across NCAR forms the Geophysical Turbulence Program, soon to become a nucleus for international collaboration on basic and applied turbulence research. Chin-Hoh Moeng and colleagues launch more than a decade of work modeling the eddies that shape marine stratocumulus clouds—clouds that strongly affect the globe's radiative balance.

1987 • Storms and Boundaries Data gathered in CCOPE (see 1981) from the first weather radar sensitive enough to see echoes in clear air lead to a field project in northeast Colorado and to radar studies led by James Wilson. The goal is to show how thunderstorm outflows can trigger new storm cells along small-scale boundaries. The work leads to creation in the mid-1990s of the Auto- nowcaster, which projects storm growth and movement up to an hour in advance. 1990s 1990 • Frontal Twist The MM4 model (see 1982) confirms striking observations, made several years earlier, of an intense low-pressure center in the North Atlantic. The low had wrapped cold air almost completely around itself, "secluding" a warm pocket at its core. The finding forces revision of frontal theories developed more than 60 years earlier and helps forecasters better analyze and predict intense coastal storms. 1992–93 • Tropical Revelations UCAR coordinates logistics for 100 institutions taking part in the Tropical Ocean and Global Atmosphere Program's four-month Coupled Ocean- Atmosphere Response Experiment. TOGA COARE finds greater variability than predicted in the weather regime across the western tropical Pacific, birthplace of El Niño. The project also detects dry air aloft that fuels unexpectedly strong storms and cool, windy outflows. 1994–95 • VORTEX The Verification of the Origins of Rotation in Tornadoes Experiment canvasses the southern Great Plains over two consecutive summers, deploying people and instruments from NCAR and over a dozen other participating institutions. VORTEX captures tornado formation—and, at times, its surprising failure—from the ground and the air in greater detail than ever before. 1996 • Lassoing Lightning A Colorado field study led by NCAR examines the role of lightning in the chemical, electrical, dynamical, and microphysical makeup of thunderstorms. Measurements from the STERAO (Stratosphere-Troposphere Experiment: Radiation, Aerosols, and Ozone) project show that substantial amounts of nitrogen oxides, a precursor of ozone, are produced by lightning and are deposited primarily in the upper troposphere. The project also finds that, contrary to previous thinking, intracloud lightning can be a major source of lightning-produced nitrogen oxides. 1997–99 • Winter Storm Incubators Several field programs across the Atlantic and Pacific gather data on the genesis of the oceanic weather systems that eventually become severe coastal and continental storms. These studies help refine the idea of targeted observations: Data gathered over a small region at the heart of emerging weather features can improve the later performance of forecast models over a much larger area. UCAR at 40 Who We Are Introduction One Planet, One Atmosphere Between Sun and Earth Measuring and Modeling •When Weather Matters Most Spreading the Word Knowledge for All Looking toward the Future UCAR at a Glance List of acronyms Other UCAR Publications • UCAR | NCAR | UOP Executive editor Lucy Warner, lwarner@ucar.edu Prepared for the Web by Jacque Marshall Last revised: Fri Jan 26 17:18:32 MST 2001