Lightning represents a natural phenomenon of substantial interest. Due to its complex nature, research continues in many countries and reveals amazing results. Lightning is actively observed because of its relevance to Earth climate and air composition in addition to the classical aspects of related human fatalities and damage to forests, buildings, power lines, aircraft, structures and electronic devices. In this volume, the most important contemporary questions on lightning are addressed and analyzed under many experimental and theoretical aspects. Lightning detection techniques using ground-based and space-borne methods are described, along with network engineering and statistical analysis. Contributions detail research on atmospheric electricity, cloud physics, lightning physics, modeling of electrical storms and middle atmospheric events. Special phenomena such as triggered lightning and sprite observations are examined. Lightning-induced nitrogen oxides and their effects on atmospheric chemistry and climate are discussed. Each topic is presented by international experts in the field. Topics include: * air chemistry * convective storms * infrasound from lightning * lightning and climate change * lightning and precipitation * lightning and radiation * lightning and supercells * lightning and thunderstorms * lightning detection * lightning from space * lighting protection * lightning return strokes * observations and interpretations * spatial distribution and frequency * triggered lightning * weather extremes

The strong and continuing increase in airtraffic, the plans to build supersonicair- craftsand hypersonicspace-transportsystems, the developments ofhydrogentech- nology, andthe generalconcern onglobalchangeshave raised questionson effects of emissions from air traffic on the environment and especially the atmosphere aboveand shortlybelowthe tropopause. What are the consequences of watervap- our emissions on the formation of high clouds and global c1imate?What are the possibleeffectsofemissions on the ozonelayerin the stratosphere and uppertro- posphere?Which technological developments can help to reducethe emissions? These questions get increasing attention in the public. Some previous meetings of scientific experts have shown that the topic is of high interest but most questions cannot be answered yet to asufficientdegree. More research is necessaryand the topic requires interdisciplinarycooperation. Moreover, there is a need to document the basic knowledge required to assess possible consequences of increasing and changingtraffic. With respect to possible global changes, airtraffic at cruising alti- tude seemsto have the mostimportantinnuence and itbecomes necessaryto con- sidertechnological alternatives. The German Aerospace Research Establishment (DLR) has initiated aseries of seminars on fundamental problems ofsciences inwhich DLR is envolved. Previous seminarsconsidered: 1984 NonlinearDynamicsofTranscritical Flows 1985 UncertaintyandControl 1986 Artificial Intelligenceand Man-Machine-Systems 1987 Parallel Computing in Science and Engineering 1988 HydrocarbonOxidation 1989 Optlmizatlon, Methods and Applications, Possibilities andLimitations This bookcontainsten paperswhichhad been preparedfor presentationatthe 1990 DLR-Seminaron AirTrafficand the Environment- Background, Tendencies and Potential Global AtmosphericEffects. At the seminar, an additional paper is to be presented by Dr. Dieter H. Ehhalt.