Active Precipitation of Radiation Belt Electrons Using Rocket Exhaust Driven Amplification (REDA) of Man-Made Whistlers

Ground-based very low frequency (VLF) transmitters located around the world generate signals that leak through the bottom side of the ionosphere in the form of whistler mode waves. Wave and particle measurements on satellites have observed that these man-made VLF waves can be strong enough to scatter trapped energetic electrons into low pitch angle orbits, causing loss by absorption in the lower atmosphere. This precipitation loss process is greatly enhanced by intentional amplification of the whistler waves using a newly discovered process called rocket exhaust driven amplification (REDA). Satellite measurements of REDA have shown between 30 and 50 dB intensification of VLF waves in space using a 60 s burn of the 150 g/s thruster on the Cygnus satellite that services the International Space Station. This controlled amplification process is adequate to deplete the energetic particle population on the affected field lines in a few minutes rather than the multi-day period it would take naturally. Numerical simulations of the pitch angle diffusion for radiation belt particles use the UCLA quasi-linear Fokker Planck model to assess the impact of REDA on radiation belt remediation of newly injected energetic electrons. The simulated precipitation fluxes of energetic electrons are applied to models of D-region electron density and bremsstrahlung X-rays for predictions of the modified environment that can be observed with satellite and ground-based sensors.

Bird predation on black fly larvae and pupae in Ontario

Seven species of shore and water birds fed on immature stages of the black fly, Simulium vittatum Zetterstedt.

PREDATORS OF AEDES ATROPALPUS (COQ) (DIPTERA: CULICIDAE) AND OF OTHER MOSQUITOES BREEDING IN ROCK POOLS IN ONTARIO

Predators of Aedes atropalpus (Coq.) and of other rockpool mosquitoes were investigated at Cordova Mines, Ontario, by tagging larvae with radioactive phosphorus, P32. High radiation counts showed that six species of dytiscids, two of Hemiptera, a leech, and a minnow were predators of A. atropalpus. The dytiscid Laccophilus maculosus Germ. exceeded other arthropod predators in numbers and in degrees of radioactivity. Hydra oligactis Pallas killed but did not ingest the tagged larvae. Other evidence suggested that H. oligactis inhibits breeding by capturing young larvae and paralyzing later stages. Five species of aquatic insects were predacious on larvae of Anopheles and Culex.

SOME PREDATORS OF AEDES STIMULANS (WALK.) AND AEDES TRICHURUS (DYAR) (DIPTERA: CULICIDAE) IN WOODLAND POOLS

The predators of first- and second-instar larvae of Aedes stimulans and A. trichurus in temporary woodland pools near Belleville, Ontario, were determined mainly by use of mosquito larvae tagged with radioactive phosphorus, but in part from the presence of aedine remains found in the digestive tracts of dissected beetles. Of 428 pond animals collected from the test pools 122 were found to be radioactive above background. Among the 17 species of aquatic insects and other animals that fed on mosquito larvae, 8 species of Dytiscidae, 1 of Hydrophilidae, 1 of Limnephilidae, and 1 pond snail are regarded as important predators. Three additional species of water beetles were identified as predators from aedine remains in their digestive tracts. The abundance of the predators, and the times of occurrence of six species in relation to mosquito development, are discussed.