In addition to the better-studied land-atmospheric carbon fluxes, the land-water transfer of carbon also directly affects terrestrial carbon sequestration. The export of dissolved organic carbon (DOC) through soils is an important process for the transport of carbon from terrestrial to aquatic ecosystems. Current studies show that two physical factors related to sorption dynamics and hydrology play dominant roles in regulating DOC loading. These processes have been represented in conceptual and numerical models, but the sorption dynamics driven by atmospheric depositions (e.g. heavy precipitation, nitrogen, and sulfur) are rarely represented. Heavy precipitation obviously increases the runoff, but the DOC concentration can also be changed in different soil layers as a result. Higher nitrogen loads may increase the intact phenolic compounds in the soil, which can decrease the soil adsorption ability and increase the DOC concentration with runoff. In addition, more DOC can be produced through active soil organic carbon decomposition processes, resulting in greater DOC loading. Furthermore, decreasing sulfur deposition accelerates the soil DOC solubility and decreases the soil adsorption ability, thus more DOC could be transported to aquatic ecosystems. In addition, soil organic carbon decomposition can be more active due to increasing soil acidity. In current Terrestrial Ecosystem Model (TEM, version 6), for example, the leaching quantity of DOC is estimated by the DOC concentration of the water yield. However, the sorption impact from atmospheric depositions is not simulated. Here, we synthesize current DOC estimation methods and improve the TEM6 model by developing the TEM6-DOC extension to allow it the ability to simulate the both of these key physical processes. We parameterized this extension with published field and experimental data, and estimated the terrestrial DOC loading of the Continental United States over the period of 1981-2010. We then studied the influence of each atmospheric deposition driver on land-water DOC loading through turning on different combinations of simulation experiments. Our results suggest that 1) during this period, the average annual DOC loading increased from 35.3 Tg C yr^-1 (1981) to 64.5 Tg C yr^-1 (2010); 2) Decreasing sulfur deposition played a more important role on DOC loading, which is greater than the influence from nitrogen deposition; 3) The runoff was the main driver of the interannual variation in  DOC export; and 4) Heavy precipitation can greatly increase the total DOC loading, which was mostly exported from the forest floor, and has smaller influence on the deeper soil DOC loading.