Figure 5

Winter time series of CO, CO₂, Rn, N₂O, and δ¹³C – CO₂ from Lower Katies Bower corresponding with correlation plots (30/6/15–17/7/15). CO₂ & Rn is 10x lower in winter. Rn and N₂O soil gas tracers do not correlate with CO₂. Air-flow is dominantly from the Grand Arch (Figs 1 and 2) diluting cave air with ambient air. Winter uni-directional air-flow with low CO₂ induces speleothem growth (δ¹³C – CO₂ = −19.5‰ VPDB, Fig. 6) and shows large synchronous fluctuations in CO₂ not Rn & N₂O soil gas tracers indicating a small cave source of CO₂ from speleothem growth.