1 #include<stdio.h>
2 #include<math.h>
3 
et_a(double r_net_day,double evap_fr,double tempk)4 double et_a(double r_net_day, double evap_fr, double tempk)
5 {
6     double latent, t_celsius, result;
7 
8     t_celsius = tempk - 273.15;
9     latent = (24.0*60.0*60.0) / ((2.501 - 0.002361 * t_celsius) * pow(10, 6));
10 
11     result = r_net_day * evap_fr * latent;
12 
13     return result;
14 }
15