Dear Qiuyu,

First, remember that the temperature of an object is only an indicator of its state. What makes a glacier melt is not temperature, but the net heat flux into it.

Second, the sensible heat flux between an object and its environment is typically approximated by a rate equation that depends on the temperature gradient between the two media in contact. From that point of view, a higher air temperature would generate a larger sensible heat flux into the glacier than a lower air temperature, for a fixed glacier temperature.

Third, it is even more important to consider the time period during which the glacier is subjected to a given heat flux. Hence, a peak air temperature of 100 C that would last for only a nanosecond would have a negligible impact on the glacier, while a 12 hours exposure to 10 C average air temperature would definitely cause some melting.

Fourth, the arguments above address the issue of instantaneous heat flux and its impact on melting. The answer to your question might also depend on the length of the time period of interest (a day, a month, a year, a century, etc.)

To answer your question quantitatively with a known degree of accuracy, you should build a model of the glacier of interest and of its heat balance. This may involve multiple heat reservoirs and processes, including gains and losses due to sensible, latent and radiative processes. So there is no simple answer to your question.

Best regards, Michel.

Dear Wang,

It seems very good question. In my personal thinking, maximum temperature play important role in melting of the glacier than others. Let me explain it with example, suppose, all kind of temperature increasing i.e. Max., Min., and Average. Since, Minimum and average temperature are already lower than the maximum temperature. if temperature increases with all kind, maximum temperature will causes the maximum melting than others. Minimum and average temperature will also increase, but it will always less then maximum, Therefore, in my view, maximum temperature has greatest influence on glacier change.

The actual fact may different, this is my understanding.

Thank you,

Regards,

Mohan

Dear Qiuyu,

First, remember that the temperature of an object is only an indicator of its state. What makes a glacier melt is not temperature, but the net heat flux into it.

Second, the sensible heat flux between an object and its environment is typically approximated by a rate equation that depends on the temperature gradient between the two media in contact. From that point of view, a higher air temperature would generate a larger sensible heat flux into the glacier than a lower air temperature, for a fixed glacier temperature.

Third, it is even more important to consider the time period during which the glacier is subjected to a given heat flux. Hence, a peak air temperature of 100 C that would last for only a nanosecond would have a negligible impact on the glacier, while a 12 hours exposure to 10 C average air temperature would definitely cause some melting.

Fourth, the arguments above address the issue of instantaneous heat flux and its impact on melting. The answer to your question might also depend on the length of the time period of interest (a day, a month, a year, a century, etc.)

To answer your question quantitatively with a known degree of accuracy, you should build a model of the glacier of interest and of its heat balance. This may involve multiple heat reservoirs and processes, including gains and losses due to sensible, latent and radiative processes. So there is no simple answer to your question.

Best regards, Michel.