The key role of decadal modulated oscillation in recent cold phase

Abstract

Global temperature change is strongly affected by internal climate variability (ICV). The temporal change of the ICV on the decadal to multi‐decadal scales is referred as the decadal modulated oscillation (DMO) that plays a dominated role in the occurrence of enhanced warming and warming hiatus. However, investigation on the DMO in modern historical period has received limited attention. In this study, the ensemble empirical mode decomposition (EEMD) method was applied to the surface air temperature (SAT) during the boreal cold season to extract the DMO signal in the past century. Two most sensitive areas of DMO trend over northern Eurasia and northwestern North America were identified and used to build a time series of regionally enhanced DMO. It showed an obvious decadal periodic oscillation at 11–23 years and exhibited increasing amplitude. In addition, regression analysis using Niño3.4, Pacific Decadal Oscillation (PDO), Atlantic Multi‐decadal Oscillation (AMO), and Arctic Oscillation (AO) revealed a major role of the AO in DMO over the mid‐to‐high latitudes in the Northern Hemisphere (NH). However, such strong oscillation signal has not been detected in most of the Coupled Model Intercomparison Project Phase 5 (CMIP5) models, and the extracted regionally enhanced DMO are capable of improving the predictability of SAT over the mid‐to‐high latitudes in the NH.

Dominant role of Atlantic multidecadal oscillation in the tipping point of maximum and minimum temperatures over inner East Asia

“…To understand the modulated effect of the AMO on the decadal variability of Tmax and Tmin, we used the EEMD method to decompose the time series of weighted‐mean Tmax, Tmin of inner East Asia and the AMO, and also to decompose the time series of Tmax and Tmin at each grid in East Asia during 1950–2014. According to the frequencies of five IMFs we obtained, the component of decadal modulated oscillation (DMO) component is the sum of IMF 3, 4, and 5, which is thought to be induced mainly by the oceanic internal climate variability (Huang et al ., 2017; Luo et al ., 2019). Though the interannual Tmax and Tmin manifested almost synchronous changes during 1982–2014, there is a distinction between their variations at the decadal time scale from 1950 to 2014, accompanied by different correlations with the AMO.…”

On the coupled interdecadal variations of the extra‐tropical surface air temperature and the isentropic meridional airmass transport in Northern winter

“…On top of the long‐term global warming, the winter surface air temperature (SAT) exhibits significant interdecadal changes (Li et al, 2022; Luo et al, 2019; Matthes et al, 2015; Xie et al, 2017). These changes can be observed from the changing rate of the long‐term warming of the global mean SAT.…”

“…For example, there appear two rapid warming periods (1910s–1930s and 1980s–1990s) and one cooling period (1940s–1970s) in the 20th century (Hansen et al, 2010; Swanson & Tsonis, 2009). The continental SAT in Northern winter is found achieving a warm peak around 2000 and then decreasing in the period of 2001–2013 (Luo et al, 2019). Decadal changes of the winter continental SAT also show remarkable regional differences.…”

“…As for the influencing factors for the interdecadal changes of the SAT over the NH, some studies emphasized on their associations with the atmospheric internal variabilities including changes of the Siberian high (Gong et al, 2001; Sung et al, 2018), the Aleutian Low (Overland et al, 1999), the Ural blocking (Cohen et al, 2014; Luo et al, 2016; Yao et al, 2017), the AO (Gong et al, 2019; He et al, 2017; Li et al, 2022; Woo et al, 2012) and the stratospheric polar vortex (Garfinkel et al, 2017; Kim et al, 2014; Zhang et al, 2018). Other studies link the SAT changes to oceanic variabilities including sea surface temperature (Chen et al, 2022; Cohen et al, 2020; Dai et al, 2015; Dong & Dai, 2015; Luo et al, 2019; Parker et al, 2007; Steinman et al, 2015; Tollefson, 2014; Xie et al, 2019) and sea ice (Kim & Son, 2016; Kug et al, 2015; Mori et al, 2019; Overland et al, 2015; Petoukhov & Semenov, 2010; Screen et al, 2018; Zhang et al, 2018), and to other external processes such as volcanic eruption (Santer et al, 2014) and solar radiation (Wang & Dickinson, 2013). While some studies attributed the recent ‘cold Eurasia’ to the sea ice loss or the reduced snow cover due to the Arctic warming amplification (Cohen et al, 2014, 2020; Kim et al, 2014; Kim & Son, 2016; Kug et al, 2015; Mori et al, 2014, 2019; Zhang et al, 2018), some other studies showed the influence from the Pacific decadal oscillation (PDO) and the Atlantic multi‐decadal oscillation (AMO) on the ‘warm Arctic‐cold Eurasia’ (Luo et al, 2022; Sung et al, 2018; Yu et al, 2020).…”