Martian north polar cap 1996-1997

In order to investigate the interannual variability of the regression of th e martian north polar cap, the regression of the martian north polar cap du ring the 1996-1997 apparition is examined utilizing measurements with CCD i mages. The regression of the north polar cap in 1996-1997 as determined from our m easurements is in excellent agreement with concurrent observations using th e Hubble Space Telescope, The regression of the north polar cap in 1996-199 7 seems to be a little faster than the mean regression or the regression in 1979-1980 after L-s = 51 degrees but seems to be similar to those in 1946, 1948, 1950, 1972, 1977-1978, and 1994-1995, (C) 1999 Academic Press.