Martian North Polar Cap 1996–1997

In order to investigate the interannual variability of the regression of the martian north polar cap, the regression of the martian north polar cap during the 1996–1997 apparition is examined utilizing measurements with CCD images. The regression of the north polar cap in 1996–1997 as determined from our measurements is in excellent agreement with concurrent observations using the Hubble Space Telescope. The regression of the north polar cap in 1996–1997 seems to be a little faster than the mean regression or the regression in 1979–1980 afterLs=51° but seems to be similar to those in 1946, 1948, 1950, 1972, 1977–1978, and 1994–1995.