The atmospheric travel distance of persistent organic pollutants-revisit and application in climate change impact on long-rang transport potential

Abstract

This study developed a model to measure long-range transport potential (LRTP) of persistent organic pollutants (POPs). To be consistent with the nature of atmospheric transport, LRTP is derived from a perturbation solution of an atmospheric transport model (ATM) for persistent chemicals. A characteristic travel distance (CTD) is defined to express the LRTP and derived from the perturbation solution of the ATM. Compared with various LRTP models developed previously, this model provides a tool to assess the persistence and LRTP of a toxic chemical, derived by taking into account the influence of surface characteristics and turbulence on the LRTP. Given these advantages, the model can be further extended to quantify the changes in LRTP induced by different climate change scenarios. The new model demonstrates that the CTD increases with increasing height associated with increasing wind speed, temperature, and decreasing decaying effect of the surface friction. The influences of the surface characteristics, dry deposition, and precipitation washout on the CTD are discussed. The model was also applied to assess the response of the CTDs of POP to the 21st-century climate change under different emission scenarios. Results show the longer CTDs associated with increasing global mean temperature and shorter CTDs by rising global precipitation. It was found that increasing precipitation in the late 21st century could alter the increasing CTD trend induced by rising temperature.