Page 16 - 《高原气象》2023年第1期

高 原 气 象 42 卷
12

A Review of the Research Progress on the Drivers of the

"Arctic amplification" Phenomenon and Its Influence

HAN Xiaoxiao ， MENG Xianhong ， ZHAO Lin ， LI Zhaoguo ， AN Yingying ， LIU Yumeng 1， 2
1
1
1， 2
1， 2
1
（1. Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions， Northwest Institute of
Eco-Environment and Resources， Chinese Academy of Sciences， Lanzhou 730000， Gansu， China；
2. University of Chinese Academy of Sciences， Beijing 100049， China）
Abstract： Since the 21st century， due to global warming， the Arctic near-surface temperature increases rapidly，
the warming rate can reach more than twice the global average rate， known as the "Arctic amplification" （AA）
phenomenon. This paper discusses the causes of the Arctic amplification effect from three aspects： first， in the
Arctic climate feedback， the decrease of sea ice leads to the increase of open sea surface， the absorption of solar
radiation increases， the sea-air interaction is enhanced， and the sea ice melts further. This is positive feedback.
Second， due to the low absolute temperature in the Arctic， according to Planck's radiation law， Planck feedback
is negative in the Arctic， but it promotes the Arctic amplification effect. Third， more open sea and higher temper‐
ature increase the humidity and the number of clouds in the Arctic. Due to the greenhouse effect of water vapor，
the lower wave radiation increases， and it promotes the near-surface layer heating. Water vapor and cloud feed‐
back on the Arctic warming contribution has significant seasonality， mainly occurring in winter. The increase of
temperature thickens the atmospheric column. The change of the upper-pressure gradient causes the change of
zonal wind， the zonal component decreases and the meridional component increases， forms the ridge， through
which the lower latitude region can exchange heat and water vapor with the Arctic. The Arctic Oscillation （AO）
and the North Atlantic Oscillation （NAO） have also been confirmed related to Arctic warming. The Atlantic Me‐
ridional Overturning Circulation （AMOC） anomaly was once thought to be the driver of Arctic warming. Recent
studies suggest it is more likely to be the result of Arctic warming. The Arctic amplification influences mid-lati‐
tude and even global climates by affecting atmospheric circulation. Warming in the Arctic strengthens the Siberi‐
an High， the growth of the duration of the Siberian High and its expansion into East Asia result in enhanced cold
advection in the coastal areas of East Asia and adjacent seas in winter， affecting the East Asian Winter Wind Sys‐
tem（EAWM） and promoting the flow of cold air to East Asia. It will result in severe winter cold in East Asia，
forming a "warm Arctic-cold Eurasian" pattern. In addition， Arctic warming leads to cold events in eastern North
America， corresponding to the 250 hPa anomalous elevation field， forming low troughs. Winter climate waves
can be formed by those low troughs and high ridges over the northeastern Pacific Ocean or Greenland. It is be‐
lieved that Arctic warming and sea ice loss can affect the mid-latitudes through two mechanisms： first， Arctic
warming changes the zonal wind by affecting the pressure field， then increases the blocking event. However， the
research shows that the effect of this mechanism on the mid-latitude is not significant. Second， it affects the atmo‐
spheric circulation of the northern hemisphere through trophic-stratospheric coupling， but this mechanism is still
controversial. However， due to flaws in research methods and uncertainty in the data， the factors affecting the
Arctic amplification effect are still controversial. For example， many studies believe that ice and snow albedo
feedback is the core factor driving the “Arctic amplification” phenomenon， and other factors indirectly affect the
Arctic amplification through sea ice and snow melting. Some studies have shown that even without considering
the role of sea ice， the Arctic amplification phenomenon is still significant. Therefore， it is particularly important
to improve research methods and the quality and accuracy of data. Finally， the existing problems are put forward.
Key words： Arctic amplification； drivers； sea ice reduction； radiation feedback； poleward transport