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Volatiles play an important role in the dynamical and chemical processes in the Earth. The presence of volatiles drastically changes mineral stability and rheological behavior of the rocks. Chemical fractionation, such as partial melting, hydration, and dehydration are controlled by volatiles in the rocks. Volatiles enhance the production of magmas and drive their ascent and volcanic eruption. The atmosphere and hydrosphere have been generated by variety of degassing events from the mantle through volcanism. Some volatiles in the Earth's surface have been suggested to be recycled back into the mantle beyond subduction zones. Although the significance of volatiles in the Earth's evolution has been recognized, each of these processes is poorly constrained. We therefore welcome contributions from experimental, observational, and modeling studies that help shed light on the behavior, chemical/physical characteristics, and flux/budget of volatiles, such as hydrogen, carbon, nitrogen, noble gases, halogens, and sulfur. We encourage studies linking the behavior of multiple volatile elements and their isotopic compositions. Studies investigating the linkage between volatile and solid geochemical tracers, the phase equilibria of volatile-bearing mantle assemblages, and the effect of volatiles on the physical properties of the mantle are also welcome.