We have performed realistic 3D radiation MHD simulations of the solar atmosphere. These simulations show jet-like features that are similar to the type II spicules discovered with Hinode's Solar Optical Telescope. These type II spicules have been associated with so-called rapid blueshifted events (RBE's) on the solar disk, and with significant blueward asymmetries in transition region and coronal lines at the footpoints of coronal loops (discovered with Hinode's EIS). These observational results and their ubiquity suggest they may play a significant role in providing the corona with hot plasma. We will present a detailed comparison of the properties of the simulated jets, with those of type II spicules (observed with Hinode) and RBE's (with ground-based instruments). We will present analysis of a wide variety of synthetic emission lines from the simulations covering temperatures from 10,000 K to several million K, and compare their intensities, velocities, line widths and asymmetry with those of the observed phenomena. We will also show how the formation mechanism of these jets (reconnection at tangential discontinuities) complicates efforts to establish a firm link between observations of magnetic fields and of chromospheric flows, and suggests that magnetic field observations at chromospheric heights may be crucial to establish from observations how these jets are formed.