Michael T. Mellon Olivier Gasnault B. Diez R.C. Elphic Justin Hagerty D. J. Lawrence S. Maurice T.H. Prettyman William C. Feldman 2007 <p><span>Neutron leakage currents measured using the Mars Odyssey Neutron Spectrometer are used to develop a two‐layer model of the distribution of hydrogen (here parameterized as water‐equivalent hydrogen, WEH) at high northern latitudes. The WEH abundance in the upper layer, Wup, was found to range between 1% and about 5%. The maximum value of the apparent thickness, D, of this upper layer peaks at about 60° latitude, giving the appearance of zonal bands of enhanced D in both hemispheres. This maximum is consistent with an expected transition from WEH contained solely in hydrous minerals at lower latitudes, to WEH contained both in the forms of water ice and water of hydration at high latitudes. A strong anti‐correlation between the WEH concentration in the lower layer and apparent depth, D, at high latitudes is observed and may provide clues to the origin of these deposits.</span></p> application/pdf 10.1029/2006GL028936 en American Geophysical Union Vertical distribution of hydrogen at high northern latitudes on Mars: The Mars Odyssey Neutron Spectrometer article