Craig Tepley likes to exploit both optical and radar techniques to explore the middle and upper atmosphere. He joined the Arecibo staff in 1983 and has been involved in many aspects of experimental work throughout the atmosphere and ionosphere. Such studies extend from investigations of the high altitude exospheric neutral hydrogen combined with measurements of the topside proton concentration, to the recently developed lower and middle atmospheric Doppler Rayleigh lidar observations of neutral winds and temperatures.
Craig's current interests include extending the Rayleigh lidar work to higher altitudes and to couple it with resonance fluorescence lidar observations of atmospheric composition and chemistry. Probing the upper mesosphere with resonance lidar beautifully complements incoherent scatter radar observations of the total ionization content of lower ionospheric sporadic layers, and twilight optical spectroscopic measurements of various metallic species. Such complementary investigations allow us to advance our understanding of the chemical composition of sporadic layers of ionization, and helps clarify the dynamic mechanisms involved in ion layer formation.