Prof. Shi Yaolin’s Team Research Findings on Ice Cave Reported by BBC News

Published: 2015-12-30
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The British Broadcasting Corporation (BBC News) had an online interview with CAS Academician and TWAS Member Professor Shi Yaolin. It reported at length his team's research findings about ice caves in the report, “The impossible ice caves that stay frozen through summer” (http://www.bbc.com/earth/story/20151211-the-impossible-ice-caves-that-stay-frozen-through-summer).

A published research paper, “Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China”, by Professor Shi and his student Dr. Yang Shaohua, attracted the BBC’s interest. Ice caves exist in locations where the annual average air temperature is higher than 0℃. An example is Ningwu ice cave, Shanxi Province, which is also the largest ice cave in China. How to explain the mechanism of its formation and preservation is a challenging task.

In order to quantitatively investigate this problem, Professor Shi’s research team used the finite-element method to simulate the heat transfer process at the ice cave. There were two major control factors. First, there is the seasonal asymmetric heat transfer wherein heat is inefficiently transferred into the ice cave from outside by conduction in spring, summer and fall. In winter, thermal convection occurs which efficiently transfers heat out of the ice cave, thus cooling it down. Secondly, the ice–water phase change provides a heat barrier for heat transfer into the cave in summer. There are Chinese tourism managers who have installed airtight doors at ice cave entrances with the intention of protecting the caves. However, calculations indicate that such doors prevent cooling air circulation in winter which will cause the ice caves to melt within forty years.

Prof. Shi's research is popularizes science concerning the effects of climate change, including such relevant factors as tourists, heated colored lights, and climatic conditions, to better understand the sustainable maintenance of ice caves. Science News – Magazine of The Society for Science & The Public, has also reported Prof. Shi’s ice cave research (https://www.sciencenews.org/article/how-melt-ice-cave).

By Chang Yue