文献类型：期刊文献

英文题名：Investigating the Uncertainty in Global SST Trends Due to Internal Variations Using an Improved Trend Estimator

作者：Lian, Tao[1];Shen, Zheqi[1];Ying, Jun[1];Tang, Youmin[1,2];Li, Junde[1];Ling, Zheng[3]

机构：[1]Second Inst Oceanog, State Key Lab Satellite Ocean Environm Dynam, Hangzhou, Zhejiang, Peoples R China;[2]Univ British Columbia, Environm Sci & Engn, Prince George, BC, Canada;[3]Guangdong Ocean Univ, Guangdong Key Lab Coastal Ocean Variabil & Disast, Zhanjiang, Peoples R China

年份：2018

卷号：123

期号：3

起止页码：1877

外文期刊名：JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS

收录：SCI-EXPANDED(收录号：WOS:000430918500017)、、Scopus(收录号：2-s2.0-85043352652)、WOS

基金：We gratefully acknowledge two anonymous reviewers for insight comments and suggestions that aided the revision of the manuscript. The HadISST1 data set is obtained from the Met Office Hadley Centre (http://www.metoffice.gov.uk/hadobs/hadisst/). The rest of the SST data sets are obtained from the NCEP data center (https://www.esrl.noaa.gov/psd/data/gridded/). This work is supported by grants from the Second Institute of Oceanography, SOA (QNYC201501), and the National Natural Science Foundation of China (41506025, 41606012, 41530961, 41690121, and 41690120).

语种：英文

外文关键词：internal variation; secular trend

外文摘要：A new criterion was proposed recently to measure the influence of internal variations on secular trends in a time series. When the magnitude of the trend is greater than a theoretical threshold that scales the influence from internal variations, the sign of the estimated trend can be interpreted as the underlying long-term change. Otherwise, the sign may depend on the period chosen. An improved least squares method is developed here to further reduce the theoretical threshold and is applied to eight sea surface temperature (SST) data sets covering the period 1881-2013 to investigate whether there are robust trends in global SSTs. It is found that the warming trends in the western boundary regions, the South Atlantic, and the tropical and southern-most Indian Ocean are robust. However, robust trends are not found in the North Pacific, the North Atlantic, or the South Indian Ocean. The globally averaged SST and Indian Ocean Dipole indices are found to have robustly increased, whereas trends in the zonal SST gradient across the equatorial Pacific, Nino 3.4 SST, and the Atlantic Multidecadal Oscillation indices are within the uncertainty range associated with internal variations. These results indicate that great care is required when interpreting SST trends using the available records in certain regions and indices. It is worth noting that the theoretical threshold can be strongly influenced by low-frequency oscillations, and the above conclusions are based on the assumption that trends are linear. Caution should be exercised when applying the theoretical threshold criterion to real data.