Yf. Shi et al., Decadal climatic variations recorded in Guliya ice core and comparison with the historical documentary data from East China during the last 2000 years, SCI CHINA D, 42, 1999, pp. 91-100
The high-resolution records of delta(18)O and snow accumulation variations
from the Guliya ice core provide valuable data for research on climatic var
iations at a decadal resolution during the past 2000 years in China. Based
on the ice core data, five spells have been divided: the warm and wet perio
d before 270 AD, the cold and dry period between 280 and 970 AD, the modera
te and dry period between 970 and 1510 AD, the well-defined "Little Ice Age
" with drastic cold-warm fluctuations between 1510 and 1930 AD and the warm
ing period since 1930 AD. According to the combination of temperature and p
recipitation, cold events (55 times) surpass warm ones (26 times), and dry
events (55 times) surpass wet ones (45 times). Cold-wet events (14 times) a
re less than cold-dry ones (16 times), while warm-wet events (10 times) are
more than warm-dry ones (4 times). If the difference of 2 parts per thousa
nd in delta(18)O (corresponding to 3K in temperature) between two or three
adjacent decades is taken as the criterion of it, the abrupt change has tak
en place 33 times or so since the 3rd century. Among them are four large on
es, occurring in 250-280, 550-580, 1220-1260, and 1520-1560 AD respectively
. Comparison of the ice core data with the latest comprehensive research re
sults on historical documents of East China shows that the great climatic e
vents appeared simultaneously or at the same age in the ice core record and
in the documentary data, suggesting that consistences and similarities in
climatic variation among different areas are far away from each other in th
e lower to mid-latitudes. However, there is a great difference between them
during the Medieval Warm Period, which is conspicuous in the historical do
cuments hut not in the ice core. In addition, the first cold event of the L
ittle Ice Age on East China was 60 years earlier than that of the Guliya Ic
e Cap, when the degree of cooling in West China is more intensive than that
of East China. But the third cold event in East China lagged behind that i
n West China during the late 19th century. The 1820s cold event in both Wes
t and East China may be caused by the magnificent Tambora volcanic eruption
in 1815.