New nitrogen comes from the air, which is 78 % nitrogen by volume, but it is almost all in the form of nitrogen gas. (sciencemag.org)
Because biological activity is limited by nitrate availability in the North Pacific Ocean, the input of new nitrogen from the atmosphere may increase photosysnthesis in the sunlit layers and export of carbon - rich organic material out of the surface ocean into the deep. (sciencedaily.com)
So biogeochemist William Wieder of the National Center for Atmospheric Research in Boulder, Colorado, and colleagues looked at the projections for new plant growth in the various models and considered how much new nitrogen and phosphorus would be required for these projections to be met. (sciencemag.org)