A class of large solution of 2D tropical climate model without thermal diffusion

In this paper, we consider the Cauchy problem of 2D tropical climate model without thermal diffusion and construct global smooth solutions by choosing a class of special initial data whose $L^{\infty}$ norm can be arbitrarily large

Ill-posedness for the periodic Camassa--Holm type equations in the end-point critical Besov space B∞,11B^{1}_{\infty,1}

For the real-line case, it is shown that both the Camassa--Holm \cite{Guo} and Novikov equations \cite{Li-arx} are ill-posed in $B_{\infty,1}^{1}$. In this paper, by presenting a new construction of initial data which leads to the norm inflation phenomena, we prove that both the periodic Camassa--Holm and Novikov equations are also ill-posed in $B_{\infty,1}^{1}$.Comment: arXiv admin note: substantial text overlap with arXiv:2201.02839; text overlap with arXiv:2112.14104, arXiv:2207.08190, arXiv:2104.0597