CONTRIBUTION OF OBLIQUELY INCIDENT PARTICLES TO NEUTRON MONITOR COUNTING RATE

We describe a new method for calculating geomagnetic cutoffs that inco rporates obliquely incident primaries, and we use it to interpret a se a level neutron monitor latitude survey. Effects due to obliquely inci dent primaries are significant and may be responsible for anomalies ob served in this and other latitude surveys. We define an ''apparent'' c utoff that takes these obliquely incident particles into account. Use of our apparent cutoff in a Dorman function fit to the 1994-1995 Barto l Research Institute-University of Tasmania latitude survey data resul ts in a significant improvement over use of the more conventional effe ctive vertical cutoff.