A foundational challenge inhibiting fundamental study of atmospheric corrosion is the limited ability to directly probe physicochemical processes occurring within electrolytes on surfaces at the micro- and sub-microscale. This talk will overview current and emerging in situ methods for electrochemical and chemical characterization of atmospherically corroding surfaces. Multi-electrode array sensing, microelectrode techniques, optical spectroscopy and other methods will be addressed along with current limitations and future prospects. Some recent advances in these areas will be exemplified through discussion of current research aimed at understanding the thermodynamic and kinetic linkages between evolving electrolytes and electrochemical processes for sodium chloride deposits on copper and aluminum. The role of integrated computational approaches as a means of advancing in-situ methods and providing complimentary physicochemical information will be addressed.