Figure 4.

Model sensitivity in ¹⁷O-excess over δ′¹⁸O for different variables and parameters during evaporation and recharge for initial water with Salar de Llamara groundwater composition (black dot). Open symbols represent steady states for E/I of 0.5 and 1 at given h, respectively. Normal boundary conditions (solid line) are ρ = 1.1 g/cm³, n = 0.5, δ¹⁸O_V = −15.3‰, ¹⁷O-excess_V = 33 per meg, h = 0.43, T = 23 °C. (a) Evaporation at variable relative humidity (h). (b) Evaporation at variable density (ρ) – proportional to salt content – from which h_eff is calculated. (c) Evaporation at variable wind turbulence, ${}^{⁎}\alpha _{l-v\_diff}^n$. (d) Evaporation at variable water temperature (T). (e–h) Evaporation at variable δ¹⁸O_V (−20.3 to −10.3‰) and ¹⁷O-excess (3 to 63 per meg).