Accuracy tests for two-time-level split-explicit scheme

Accuracy tests for two-type split-explicit integration schemes are carried out. For a better understanding of each scheme's properties, idealized simulations are performed using fully elastic equations. Since the fast-wave solver is calculated at the midpoint of a time step, the two-time-level split-explicit method demonstrates its superiority in gravity-wave simulation to the Klemp and Wilhelmson method. However, from the perspective of accuracy, the two-time-level split-explicit scheme is not attractive. It does not ensure the accuracy of large time step calculations, unlike the Klemp and Wilhelmson method.