This paper investigates the feasibility of periodic tracers (i.e., tracers injected in a periodic waveform) for subsurface characterization using numerical simulations. From a theoretical point of view, periodic tracers offer many advantages over conventional pulse or continuous tracers. For example, periodic tracers are more sensitive to various transport and reaction processes and are less susceptible to corruption by environmental noise. With the recent advances in computer-controlled injection technologies, time is now ripe for investigating the feasibility of these tracers for laboratory and field tracer tests. A series of numerical sensitivity analyses are performed in this study for assessing the sensitivity of these signals for various transport and reaction phenomena in the subsurface. Sensitivity coefficients are calculated and compared for conventional and periodic tracers for various transport phenomena. An inverse modeling case study is performed to evaluate the potential of periodic tracers for detecting the location and concentration of biological active zones. The results indicate that periodic tracers have the potential to perform significantly better than conventional tracers.