@article{oai:nitech.repo.nii.ac.jp:00004547,
 author = {Watanabe, Takeshi and Iwayama, Takahiro and Fujisaka, Hirokazu},
 issue = {2},
 journal = {PHYSICAL REVIEW E},
 month = {Feb},
 note = {We numerically study the time evolution of coherent vortices in decaying turbulence described by the Charney-Hasegawa-Mima equation with the weak dissipation. Self-organized coherent vortices develop through the mutual advection and the vortex  merging. The dimensional analysis provides the dynamical scaling law of structure function of the potential vorticity field S(k,t) = E5/4λ1/2t1/2G(k/k?(t)) [k?(t)?E-1/8λ3/4t-1/4] with a scaling function G(x), which turns out to be in good agreement with numerical experiments. In physical space, quantities related to coherent vortices develop algebraically with time. The dimensional analysis predicts that the total number N of vortices decreases as N?t-χ  with exponent χ=1/2. Moreover, it is found that the remarkable feature of this system is the approximate conservation of the area of the coherent region in the potential voracity field., application/pdf},
 pages = {1636--1643},
 title = {Scaling law for coherent vortices in decaying drift Rossby wave turbulence},
 volume = {57},
 year = {1998}
}