Chapter 12, Problem 12.143P

A shallow layer of water is exposed to the natural environment as shown

Consider conditions for which the solar and atmospheric irradiations are $G_s={\text{ 600 W/m}}^2{\text{ and G}}_{atm}=3{\text{00 W/m}}^2$ , respectively, and the air temperature and relative humidity are $T_{\infty }={27}^{\circ }C\text{ and }{\varphi }_{\infty }=0.50$ , respectively. The reflectivities of the water surface to the solar and atmospheric irradiation are ${\rho }_s=0.3\text{ and }{\rho }_{atm}=0$ , respectively, while the surface emissivity is $\epsilon =0.97$ . The convection heat transfer coefficient at the air−water interface is ${\text{h= 25 W/m}}^2\cdot \text{K}$ . If the water is at ${27}^{\circ }C$ , will this temperature increase or decrease with time?