TITLE:
Response of Permafrost Thermal Regime to Climate Change over Northern Hemisphere in the 21st Century
AUTHORS:
Wenhao Yang, Hongxia Shi
KEYWORDS:
CMIP5, Permafrost, Mean Annual Ground Temperature, Depth of Zero Annual Amplitude
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.9 No.9,
September
28,
2021
ABSTRACT: Based on the CMIP5 simulation and numerical model, the permafrost thermal
regimes over Northern Hemisphere land during the early (2016-2035), middle (2046-2065)
and late (2080-2099) period of 21st century are projected, and its relationship
with climate change is also analyzed. The results show that, relative to the
reference period of 1986-2005, the mean annual ground temperature (MAGT) over
Northern Hemisphere shows an increasing trend, with a decreasing trend of the
depth of zero annual amplitude (DZAA), and the most significant changes occur
in Siberia, Tibetan Plateau, Canada arctic and Alaska, and the changes in MAGT
and DZAA grow larger with time and emission, especially during the LP for
RCP8.5, MAGT will increase by 4 and DZAA decreases by 1.5 m (the
relative change exceeds 20%) in most regions. The changes of permafrost in the
21st century mainly depend on the changes of cold permafrost. The relationship
between MAGT and air temperature as well as that between DZAA and air
temperature suggests that the increase of MAGT and the decrease of DZAA are
related to the increase of air temperature in winter, especially in January. However,
the rate of change in MAGT and DZAA gradually declines, with the temperature increasing.