Vladimir Valentinovich Alexandrov (Russian: Владимир Валентинович Александров; born 1938; disappeared 1985) was a Soviet/Russian physicist who created a mathematical model for the nuclear winter theory. He disappeared while at the Second International Conference of Nuclear Free Zones Local Authorities in Cordoba, Spain on 31 March and his ultimate fate remains unknown, though speculation continues. One of his last papers was Man and Biosphere published in 1985; it is said to have charted the moving trend in the science of nuclear winter. It was co-authored with Nikita Moiseyev and A. M. Tarko.