High resolution nitrate analyses of snow sequences in Antarctica may provide evidence that the snow contains a chemical record of ionization from charged particles incident upon the upper atmosphere of the earth. Nitrate concentration in snow and firn will be measured on-site in Antarctica by ultraviolet spectrophotometry to detect short pulses of high nitrate concentration which can be directly related to specific solar flares known from past records of geomagnetic activity and satellite data on the charged particle fluence in the interplanetary medium. This project will analyze, at high resolution, a firn and ice core that covers the last 3000 years. With this core, it will be possible to acquire a time series that includes most of recorded history and will permit an examination of the nitrate record of major solar activity features like the Maunder, Spoerer and Wolf Minima and to obtain a detailed record of the response of the solar cycle and associated flare activity to these long-term variations.
