Comparison of ocean heat content estimated using two eddy-resolving hindcast simulations based on OFES1 and OFES2

Liao, Fanglou1,2; Wang, Xiao Hua2; Liu, Zhiqiang1,3

2022-02-07

10.5194/gmd-15-1129-2022

Geoscientific Model Development   影响因子和分区

1991-959X

1991-9603

In this study, we have compared the ocean heat content (OHC), estimated using two eddy-resolving hindcast simulations based on Ocean General Circulation Model for the Earth Simulator version 1 (OFES1) and version 2 (OFES2). Results from a global objective analysis of subsurface temperature (EN4) were taken as a reference. Both EN4 and OFES1 suggest that OHC has increased in most regions of the top 2000 m during 1960-2016, which is mainly associated with the deepening of neutral density surfaces and variations along the neutral density surfaces of regional importance. Upon comparing the results obtained from the two OFES hindcasts, we found substantial differences in the temporal and spatial distributions of the OHC, especially in the Atlantic Ocean. A basin-wide heat budget analysis showed that there was less surface heating for the major basins in OFES2. The horizontal heat advection was mostly similar; however, OFES2 had a significantly stronger meridional heat advection associated with the Indonesian Throughflow (ITF) above 300 m. Additionally, large discrepancies in the vertical heat advection were also evinced when the two OFES results were compared, especially at a depth of 300 m in the Indian Ocean. We inferred that there are large discrepancies in the vertical heat diffusion (those that cannot be directly evaluated in this study due to data unavailability), which, along with the different magnitudes of sea surface heat flux and vertical heat advection, were the major factors responsible for the examined differences in OHC. This work suggests that OFES1 provides a reasonable multi-decadal estimate of global and basin-integrated warming trends above 700 m, except for the top 300 m for the Pacific Ocean and between 300-700 m for the Indian Ocean. Although the estimates of the global OHC during 1960-2016 are consistent with observations between 700-2000 m, caution is warranted while examining the basin-wide multi-decadal OHC variations using OFES1. The seemingly suboptimal OHC estimate based on OFES2 suggests that any conclusions on long-term climate variations derived from OFES2 might suffer from large drifts, necessitating audits.

SCI

英语

第一 ; 通讯

Key Special Project for Introduced Talents Team of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)[GML2019ZD0210]

Geology

Geosciences, Multidisciplinary

WOS:000758163400001

COPERNICUS GESELLSCHAFT MBH

Web of Science

1.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen 518055, Peoples R China
2.Univ New South Wales, Sch Sci, Sino Australian Res Consortium Coastal Management, Canberra, ACT 2610, Australia
3.Southern Marine Sci & Engn Guangdong Lab Guangzho, Guangzhou 511458, Peoples R China

Liao, Fanglou,Wang, Xiao Hua,Liu, Zhiqiang. Comparison of ocean heat content estimated using two eddy-resolving hindcast simulations based on OFES1 and OFES2[J]. Geoscientific Model Development,2022,15(3).

Liao, Fanglou,Wang, Xiao Hua,&Liu, Zhiqiang.(2022).Comparison of ocean heat content estimated using two eddy-resolving hindcast simulations based on OFES1 and OFES2.Geoscientific Model Development,15(3).

Liao, Fanglou,et al."Comparison of ocean heat content estimated using two eddy-resolving hindcast simulations based on OFES1 and OFES2".Geoscientific Model Development 15.3(2022).