  The proposed ARIANNA-200 neutrino detector, located at sea-level on the Ross
Ice Shelf, Antarctica, consists of 200 autonomous and independent detector
stations separated by 1 kilometer in a uniform triangular mesh, and serves as a
pathfinder mission for the future IceCube-Gen2 project. The primary science
mission of ARIANNA-200 is to search for sources of neutrinos with energies
greater than 10^17 eV, complementing the reach of IceCube. An ARIANNA
observation of a neutrino source would provide strong insight into the
enigmatic sources of cosmic rays. ARIANNA observes the radio emission from high
energy neutrino interactions in the Antarctic ice. Among radio based concepts
under current investigation, ARIANNA-200 would uniquely survey the vast
majority of the southern sky at any instant in time, and an important region of
the northern sky, by virtue of its location on the surface of the Ross Ice
Shelf in Antarctica. The broad sky coverage is specific to the Moore's Bay
site, and makes ARIANNA-200 ideally suited to contribute to the multi-messenger
thrust by the US National Science Foundation, Windows on the Universe -
Multi-Messenger Astrophysics, providing capabilities to observe explosive
sources from unknown directions. The ARIANNA architecture is designed to
measure the angular direction to within 3 degrees for every neutrino candidate,
which too plays an important role in the pursuit of multi-messenger
observations of astrophysical sources.
