Stratospheric Ozone and Man

Volume II

Frank A. Bower

• Publisher: CRC Press
• Year: 2018
• Print ISBN: 9781315897820
• eBook ISBN: 9781351093828
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

The book, as originally conceived, was to be limited to technical considerations, but the scientific course of event has been so interwoven with non-scientific, but nevertheless related events, the authors felt necessary to include an account of this situation. Accordingly, the book is divided into five sections entitled: ? Stratospheric ozone ? Atmospheric processes influencing stratospheric ozone ? Does man influence stratospheric ozone ? Effects and research ? Public policy

Section 1: Does Man Influence Stratospheric Ozone?

Chapter 1

THE SUPERSONIC TRANSPORT

Anthony J. Broderick and Robert C. Oliver

TABLE OF CONTENTS

I.	Introduction
II.	SST Exhaust Composition
III.	The Genesis of the SST-Ozone Controversy
IV.	CIAP — NAS — COVOS — COMESA: The SST-Ozone Studies
V.	The Years 1975 to 1976: CH4 Oxidation Effects, Uncertainties, and Halocarbon Effects A. Uncertainties in the Ox−HOx−NOx Atmosphere B. Chlorofluorocarbons
VI.	The Kinetics Revolution, 1977 to 1978
VII.	1979 Status of Computed SST Effects on Ozone
VIII.	Discussion A. Attempts to Establish Predictive Validity B. Current Uncertainty of Predictions C. Anomalies D. Missing Reactions E. Multiple Solutions: A Modeling Problem F. Concluding Comments
IX.	Appendix
References

I. INTRODUCTION

By the beginning of the 1970s, the supersonic transport (SST) designs of the U.S., Great Britain and France, and the Soviet Union had been in the process of continual refinement for some 10 years. Prototypes of the Anglo-French Concorde and Soviet TU-144 had made their first flights. Simultaneously, a general environmental awareness had been building in the U.S. The year 1970 saw the initial implementation of the National Environmental Policy Act¹ (NEPA), with its clear declaration of U.S. policy on environmental preservation and enhancement; and the Clean Air Act Amendments of 1970² (CAAA), which charged the infant U.S. Environmental Protection Agency with establishing regulations which would reduce automobile emissions by a factor of 10 within about 5 years. NEPA and the Clean Air Act can, in retrospect, be viewed as major turning points on a road toward growing national concern for environmental protection and enhancement, and 1970 is the year that the SST collided with environmental interests.

The U.S., for the first time in many decades, was providing direct federal financial support for the development of commercial aircraft—the supersonic transport. Under contract to the government, the Boeing and the General Electric companies were to design, build, and test a commercially viable SST which was to carry nearly 300 passengers at 2.7 times the speed of sound between points as distant as New York and Paris. A key provision in this government-industry agreement was that development costs were to be paid back to the government by means of a royalty which would be part of the sales price for each aircraft subsequently sold by the Boeing/G.E. team. The government projected a substantial future profit from these sales, a contention viewed as overoptimistic by critics.

The direct-subsidy aspect of this arrangement rankled many. The long history of indirect federal support of commercial aircraft development—via research and development of military aircraft—was not something people seemed to be generally familiar with or, if they were, it seemed to present less of a philosophical problem. If the development of the world’s largest commercial aircraft, the Boeing® 747, had been materially enhanced by Boeing’s early work on the Air Force C-5A program; if the development of the modern high-bypass ratio turbofan engines for the Boeing® 747, the McDonnell-Douglas® DC-10, and the Lockheed® L-1011 widebody jets had been based on similar efforts, so be it. Apparently, such indirect subsidies could be rationalized on the basis of original defense needs driving the early development work, and commercial ingenuity subsequently making a profit. But the SST program was viewed by many as, purely and simply, a distasteful case of government subsidy to big business.

Concern had been expressed in the 1960s about the environmental effects of the SST, but that discontent centered almost exclusively on two issues: extreme noise on takeoff, compared to even the noisy early jets, the result of the enormous exhaust jet velocity of its four afterburning turbojet engines; and the prospect of frequent sonic booms. With regard to the sonic boom issue, it was finally agreed after many years of study and testing that sonic booms would not be tolerated by the average citizen. As a result, the U.S. Government considered that commercial supersonic flights over populated areas could not be permitted. Opponents of the SST then raised the issue of possible harm to wildlife in uninhabitated areas and to sealife from sonic booms. So in 1970 the sonic boom issue cannot really be said to have been resolved. Takeoff noise, on the other hand, was a distinctly more difficult problem. This environmental issue remains today as one of two key roadblocks, the other being energy consumption to the development of a commercially successful SST.

But there was yet another set of environmental concerns to be raised widely in 1970: what would be the effect of exhaust gases from the SST fleet? Would the large amounts of exhaust water vapor form persistent contrails or clouds? Would the amount of stratospheric ozone be reduced by the exhaust water vapor? Would nitric oxide emissions of the SST reduce stratospheric ozone? Would global climate changes result from SST operations?

II. SST EXHAUST COMPOSITION

The basic combustion chemistry of hydrocarbon fuels results in exhaust emissions of carbon dioxide (CO₂) and water vapor (H₂0). Owing to the heating of inlet air to very high temperatures, oxides of nitrogen (NO_x) are also found in the exhaust. Incomplete combustion—though combustion efficiencies of jet engines are remarkably high—results in emission of small amounts of carbon monoxide (CO) and unburned or only partially burned hydrocarbons (HC). Trace elements in the fuel itself also result in oxidized forms of emissions, with oxides of sulfur (SO_x) being of primary interest.

It is conventional to speak of the “emission index” of a jet engine when discussing exhaust emissions of a subs...

Table of contents

• Cover
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Prologue
• Section 1: Does Man Influence Stratospheric Ozone?
• Section 2: Effects and Research
• Section 3:: Public Policy
• Epilogue
• Acronyms
• Index