Pacific sea level rise patterns and global surface temperature variability

Abstract

During 1998–2012, climate change and sea level rise (SLR) exhibit two notable features: a slowdown of global surface warming (hiatus) and a rapid SLR in the tropical western Pacific. To quantify their relationship, we analyze the long‐term control simulations of 38 climate models. We find a significant and robust correlation between the east‐west contrast of dynamic sea level (DSL) in the Pacific and global mean surface temperature (GST) variability on both interannual and decadal time scales. Based on linear regression of the multimodel ensemble mean, the anomalously fast SLR in the western tropical Pacific observed during 1998–2012 indicates suppression of a potential global surface warming of 0.16° ± 0.06°C. In contrast, the Pacific contributed 0.29° ± 0.10°C to the significant interannual GST increase in 1997/1998. The Pacific DSL anomalies observed in 2015 suggest that the strong El Niño in 2015/2016 could lead to a 0.21° ± 0.07°C GST jump.

Interannual and Decadal Variability in Tropical Pacific Sea Level

“…Similar to the previous findings (i.e., Figure 2d in Peyser et al, 2016), the variability of the SSI as represented by its standard deviation is underestimated in the CMIP5 models. While most models also underestimate the mean, we do not find any correlation between the long-term mean SSI and its temporal variability (Figure 1).…”

“…The SSI is calculated as the difference of the mean DSL between the eastern (20 • S-20 • N, 160 • W-100 • W) and western (20 • S-20 • N, 120 • E-180 • E) tropical Pacific. The regions are chosen based on the DSL variability centers of the 1st empirical orthogonal function (EOF) in the AVISO and GFDL reanalysis products [13]. In the long-term mean, tropical Pacific sea level is tilted with the west higher than the east due to trade winds and water density differential (i.e., SSI is overall negative).…”

“…We quantify DSL variability in the tropical Pacific using a see-saw index (SSI) [13]. The SSI is calculated as the difference of the mean DSL between the eastern (20 • S-20 • N, 160 • W-100 • W) and western (20 • S-20 • N, 120 • E-180 • E) tropical Pacific.…”

“…To better understand the sources of model biases, we separate interannual and decadal DSL variability. Our work is focused in the region from 30 • S to 45 • N where an anomalously-fast SLR in the western Pacific has been observed during the satellite era [13]. In this region, interannual variability is dominated by El Niño/Southern Oscillation (ENSO) events.…”

Big Jump of Record Warm Global Mean Surface Temperature in 2014–2016 Related to Unusually Large Oceanic Heat Releases

“…Years 2015 and 2016 surpassed 2014 by 0.15°C (0.11°–0.19°C) and 0.21°C (0.18°–0.24°C), respectively. In 2015–2016, forecasts were published (Peyser et al, ; UK Met Office, ) predicting this jump in GMST using either operational forecast systems (Folland et al, ) or Pacific sea level anomalies along with a dynamical‐statistical method (Peyser et al, ). The subsequent observations confirm these GMST predictions.…”