This proposal is for the continuation of a study of the long term properties of cosmic ray anisotropies in interplanetary space surrounding the earth, with emphasis on the information that can be extracted from these data regarding the properties and long term variations of cosmic ray density gradients in the inner heliosphere. This work is expected to yield important information on the three-dimensional magnetic and cosmic ray profile near the earth, and its dependence on activity on the sun. It will permit studies of how the cosmic ray gradients near the earth are influenced by asymmetry of solar activity on the two solar activity hemispheres, and the way in which the dependence changes over the 11-year solar activity cycle and the 22-year solar cycle. Using data from inclined and vertical muon telescopes as well as data from other underground telescopes, it will be possible to observe these effects over a wide range of terrestrial latitudes over the period of 1965 to the present, and examine any dependence on heliospheric polarity and solar magnetic field reversal. This will allow a study of the continuing evolution of the heliospheric magnetic field and its influence on high rigidity galactic cosmic radiation in the inner heliosphere. Support is provided for continued data acquisition, reduction and interpretation, and for continued operation of currently operating large underground multi-directional muon telescope recorders at Embudo Cave and Socorro, New Mexico.
