Nitrogen chemistry absorption features in near-infrared transmission spectra. A reference model with enhanced nitrogen chemistry (Section 3.2) is perturbed in mixing ratio, temperature, and cloud fraction. The “transit depth excess” results from subtracting a model with enhanced nitrogen chemistry from an identical model without nitrogen chemistry (see the inset). The intermediate shading shows this subtraction for the unperturbed reference model. Left: reference model with enhanced NH3. Right: reference model with enhanced HCN. Dashed lines indicate covered regions. The WFC3, K-band, and Spitzer IRAC bandpasses are indicated.