The cryosphere plays a very important role in global climate change. Due to its highly sensitive to climate change, the cryosphere has a mutual dependent relationship with the liquid hydrosphere and they get feedback from each other. 

Due to the cryosphere melts, a large amount of cold fresh water empties into the sea. It will change the salinity and temperature of the ocean, and affect the global thermohaline circulation and climate change. In addition, cryosphere change has an important influence to the water resource and ecosystem. 

In the view of global water balance, the cryosphere expansion means the decrease of liquid water and weakening of water circulation. With the influence of human activities on the climate change, global cryosphere changes obviously, and the hydrological influence of the cryosphere changes the global water circulation. 

Freeze-melt processes of the cryosphere have important impacts on hydrological processes of oceans and rivers, as well as the atmospheric water cycle. Based on analysis of the composition of freshwater in oceans of the Polar Regions, the effect of the cryosphere on freshwater input to polar oceans is analyzed. 

Further, the relationship between the cryosphere and ocean thermohaline circulation is interpreted and the cryosphere contribution to sea level rise is discussed. In the freshwater cycle of the Antarctic and Arctic oceans from 60°to 90°latitude, Arctic sea ice and snow meltwater greatly exceeds water in the precipitation-evaporation process in the water cycle. 

Arctic snowmelt, river recharge, mountain glaciers, ice caps and the Greenland ice sheet, as well as changes in cryosphere elements such as the Antarctic ice sheet, sea ice, polynya and others, can significantly affect the strength of deep water convection and thereby the ocean thermohaline circulation. 

The research shows the cryosphere affects the process of global water cycle in different temporal and spatial scales. The cryosphere also plays an important hydrological role in oceanic cycle. And the change of fresh water in North and South Poles will affect the process of global ocean circulation and global climate. 

This research is financially supported by the National Natural Science Foundation of China (No. 41030638), and Major National Scientific Research Projects (No. 2013CBA01808), and the research achievement was published in Chinese Science Bulletin, under the title “The hydrological impact of cryosphere water cycle on global-scale water cycle”. 

Corresponding author: Prof. Ding Yongjian

E-mail: dyj@lzb.ac.cn