WMOD00311

• Title: Harold D. Orville Symposium - Forty Years of Modeling Clouds and Weather Modification
• Date: 4/26/2003
• Weather Modification - Doc Type: Report

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Preface

Over the past forty years, we have witnessed significant progress in the understanding of
cloud microphysics and cloud dynamics, their interactions and their practical
implications. It is now understood that cloud growth and development, and ultimately
storm severity, is the result of a complex interplay of cloud microphysical processes,
which influence storm thermodynamics and vertical accelerations, and cloud dynamics,
acting on a background of atmospheric and topographic environmental conditions. The
results ofthis interplay determine cloud development, the nature of cloud structure, the
precipitation type and amount, and storm severity. These in turn, have implications for
such issues as: air quality, lightning, precipitation modification, and safety issues related
to weather hazards. This progress is obviously a collective effort by many researchers
over many decades. However, there is one individual who has played a key role in the
many contributions to this field that is Prof. Harold D. Orville.

In his forty years' of research, Prof. Orville has worked on a variety of research topics,
ranging from the modeling of clouds, flow over topography, cloud microphysics, cloud
dynamics, weather modification, to acid rain. In his forty years of teaching at the Dept. of
Atmospheric Sciences (formerly, Dept. of Meteorology), Dr. Orville has produced many
outstanding students. In celebration of Dr. Orville's distinguished career, the Institute of
Atmospheric Sciences of the South Dakota School of Mines and Technology has
organized a special symposium with a focus on cloud modeling and weather modification
on Saturday, 26 April 2003. The program consists often invited speakers who will
provide an overview of progress and current understanding of the state of science in key
areas. They will also highlight critical issues fundamental to future progress. Thus this
symposium will provide mileposts for the current state of scientific understanding and
point toward key directions for future investigators. This preprint volume provides a
permanent record of the presentations.

We extend our appreciation to members of the local organizing committee of this
symposium and the staff of the Institute of Atmospheric Sciences. Special thanks go to
Elaine Baker (SDSM&T), Connie Crandall (SDSM&T), Kim Kimbro (UCAR) for their
capable assistance in the organizing of the symposium, and the publication of the
brochure and preprint volumes. Finally we wish to acknowledge the support provided by
the Institute of Atmospheric Sciences, the South Dakota School of Mines and
Technology, the Office of Naval Research, and the University Corporation for
Atmospheric Research for this symposium.

Program Committee

Simon Chang
Mark Hjelmfelt
Ying-Hwa Kuo
Paul Smith