摘要
The rapid increase of the atmospheric carbon dioxide (CO_2) and its great impact on global climate since the industrial revolution has drawn much attention of the science community [1], while the change of oxygen (O_2) has been concerned only in the recent decades and mainly in oceanic regions [2]. It has been observed that oxygen concentration has decreased in the open ocean thermocline in many ocean regions since 1960s.
The rapid increase of the atmospheric carbon dioxide （CO2） and its great impact on global climate since the industrial revolution has drawn much attention of the science community [1], while the change of oxygen （O2） has been concerned only in the recent decades and mainly in oceanic regions [2].
