Chemical model of one quadrant of our adopted disk produced by DALI. (a) Total oxygen and carbon partition between thegas and ice. We show the gas scale height with a thin dashed line, and the scale height of the large grains with a dot-dashed line. We show the water, carbon dioxide, carbon monoixde, and molecular oxygen ice lines with the black, silver, white, and grey contours, respectively. To the right and below these curves the disk is sufficiently cold that these molecular species freeze out onto the dust grains. The letters A–E refer to locations of chemical interest (see text). (b) Carbon-to-oxygen ratio in the gas and ice. The white contour is solar C/O, while blue and orange represents sub- and super-solar C/O, respectively.