"tendency_of_X" means derivative of X with respect to time. The construction "atmosphere_moles_of_X" means the total number of moles of X contained in the entire atmosphere, i.e, summed over the atmospheric column and over the entire globe. The chemical formula of molecular hydrogen is H2.
"tendency_of_X" means derivative of X with respect to time. The construction "atmosphere_moles_of_X" means the total number of moles of X contained in the entire atmosphere, i.e, summed over the atmospheric column and over the entire globe. The chemical formula of molecular hydrogen is H2.