A suite of gas phase in situ measurements were deployed on the NSF/NCAR C-130 during the Ice in Clouds Experiment – Tropical campaign in July, 2011. Carbon monoxide, ozone, methane, and carbon dioxide were measured continuously with a time resolution of 2-s, 0.4-s, 0.2-s and 0.2-s, respectively. These insoluble trace gases can be used as indicators of entrainment, especially when a large gradient is observed between boundary layer and free tropospheric air, and in the absence of cloud precipitation. This condition was consistently observed in the ICE-T observations. Entrainment analysis of these conserved tracers will be presented for case studies of non-precipitating towering cumulus.