Introduction - Severe Convective Storms and Tornadoes: Observations and Dynamics - page 3

To the latter end, in this chapter the reader is referred to Figures 1.1 -1.10 , which
are a non-exhaustive mosaic of some of the major players in severe storm
research in the past six decades and some of the instrumentation used in field
experiments.
Modern observing systems and some of the techniques used to study severe
convective storms using them are described briefly in many of the chapters, but
students and readers are referred elsewhere for more details. The following
chapter (Chapter 2) describes the basic physics and thermodynamics of convec-
tion, including the older plume and thermal models along with a brief
introduction to the classic linear analysis of Rayleigh-Be´ nard convection. The
dynamics and behavior of the two basic types of convective building blocks,
''ordinary cells'' and ''supercells'' are detailed in Chapters 3 and 4, respectively.
The former includes discussion of density-current dynamics, downdrafts, and
multicell behavior. Chapter 5 is a treatment of the dynamics of larger conglomer-
ates of convective cells, ''mesoscale convective systems (MCSs)'', Tornadoes,
which can form in either type of convective cell and in some MCSs, are then
discussed in Chapter 6. There is a brief discussion of short-range forecasting, the
possible effects of climate change on severe convective storm occurrence, and
topics for future research in Chapter 7.
1.2 A BRIEF HISTORY OF SEVERE STORM FIELD PROGRAMS AND
NUMERICAL MODELING EFFORTS
1.2.1 Field programs and instrument development
The seminal field program for the study of severe convective storms was the
Thunderstorm Project, conducted near Orlando, Florida in the summer of 1946
and near Wilmington, Ohio in the summer of 1947. An objective of this field
program was to learn enough to be able to reduce the likelihood of thunderstorm-
related airplane crashes. In situ measurements were made in and around thunder-
storms in aircraft and at the surface. Rawinsonde measurements were made
profiling the vertical thermodynamic and wind structure of the troposphere, and
radar reflectivity data were collected, enabling the identification of the entire life
cycle of convective storms. Most field programs since then have been focused on
the study of convective storms, severe or otherwise, and have been variations on
the original theme of the Thunderstorm Project. The University of Chicago-based
leaders of the Thunderstorm Project, Horace Byers and his graduate student
Roscoe Braham, named the precipitation region associated with a discrete updraft
in a convective storm a ''cell'', in analogy to a biological cell, and identified three
distinct stages in the life cycle of a thunderstorm cell. Braham's M.Sc. thesis was
incorporated into a classic and much referenced (even up to the current time)
volume attributed to both Byers and Braham and published in 1949.