\(RMSE\ =\frac{1}{50}\text{\ \ }\sum_{y=2051}^{2100}{}\sqrt{\frac{1}{N_{\text{lat}}N_{\text{lon}}}\ \sum_{i}^{N_{\text{lat}}}\sum_{j}^{N_{\text{lon}}}L\left(i\right)\left(x_{i,j,y}-\left|x_{i,j,y,n}^{t}\right|_{n}\right)^{2}}\), (1)