FN Archimer Export Format
PT J
TI The Thermocline Biases in the Tropical North Pacific and Their Attributions
BT 
AF Zhu, Yuchao
   Zhang, Rong-Hua
   Li, Delei
   Chen, Dake
AS 1:1,2,3;2:1,2,3,4,5;3:1,2,3;4:6,7;
FF 1:;2:;3:;4:;
C1 CAS Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
   Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
   Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
   Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xian, China
   University of Chinese Academy of Sciences, Beijing, China
   State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
   Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
C2 CHINESE ACAD SCI, CHINA
   CHINESE ACAD SCI, CHINA
   QNLM, CHINA
   CHINESE ACAD SCI, CHINA
   UNIV CHINESE ACAD SCI, CHINA
   SIO, CHINA
   SOUTHERN MARINE SCIENCE ENGINEERING GUANGDONG LAB, CHINA
IF 5.38
TC 12
UR https://archimer.ifremer.fr/doc/00688/79983/82944.pdf
LA English
DT Article
DE ;Climate models;Model errors;Model evaluation/performance
AB The tropical thermocline plays an important role in regulating equatorial sea surface temperature (SST); at present, it is still poorly simulated in the state-of-the-art climate models. In this paper, thermocline biases in the tropical North Pacific are investigated using the newly released CMIP6 historical simulations. It is found that CMIP6 models tend to produce an overly shallow thermocline in the northwestern tropics, accompanied by a deep thermocline in the northeastern tropics. A pronounced thermocline strength bias arises in the tropical northeastern Pacific, demonstrating a dipole structure with a sign change at about 8°N. These thermocline biases are accompanied with biases in the simulations of oceanic circulations, including a too weak North Equatorial Countercurrent (NECC), a reduction in water exchanges between the subtropics and the equatorial regions, and an eastward extension of the equatorward interior water transport. The causes of these thermocline biases are further analyzed. The thermocline bias is primarily caused by the model deficiency in simulating the surface wind stress curl, which can be further attributed to the longstanding double-ITCZ bias in the tropical North Pacific. Besides, thermocline strength bias can be partly attributed to the poor prescription of oceanic background diffusivity. By constraining the diffusivity to match observations, the thermocline strength in the tropical northeastern Pacific is greatly increased. 
PY 2021
PD MAR
SO Journal Of Climate
SN 0894-8755
PU American Meteorological Society
VL 34
IS 5
UT 000615495000005
BP 1635
EP 1648
DI 10.1175/JCLI-D-20-0675.1
ID 79983
ER

EF