回転球面上の減衰性2次元乱流からのパターン形成

抄録

Time-evolutions of decaying turbulence in two-dimensional non-divergent fluid on a rotating sphere were conducted with high-resolution numerical model to examine what stream pattern appears finally.
To investigate the condition needed for each pattern to appear in detail, higher-resolution model are used and wider parameter range of initial condition or angular velocity of sphere rotation are swept than other past researches on the same subject.
As a result, it is confirmed that the appearance of easterly polar vortex when the angular velocity of sphere rotation is rapid is a robust feature. Furthermore, it turned out to be necessary for band structure of zonal flow to appear in middle and low latitudes that initial energy must be injected into small scale enough as well as the angular velocity of sphere rotation is rapid.