The paper “Singularity formation and global existence of classical solutions for one-dimensional rotating shallow water system“, co-authored by Bin Cheng, Peng Qu (Fudan University, Shanghai) and Chunjing Xie (Shanghai Jiao Tong University), has been published in the SIAM Journal of Mathematical Analysis.  A link to the published version is here.  The paper studies classical solutions of the one-dimensional rotating shallow water system.  The main results are twofold. Firstly, they prove finite-time singularity formation by analyzing the weighted gradients of Riemann invariants and utilizing conservation of energy.  Secondly, when the initial data have constant potential vorticity, the global existence of small classical solutions is established.