The relative contributions of tropical Pacific sea surface temperatures and atmospheric internal variability to the recent global warming hiatus

2017 ◽  
Vol 44 (15) ◽  
pp. 7945-7954 ◽  
Author(s):  
Clara Deser ◽  
Ruixia Guo ◽  
Flavio Lehner
Keyword(s):  
Global Warming ◽  
Internal Variability ◽  
Tropical Pacific ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Global Warming Hiatus ◽  
Warming Hiatus

scholarly journals A Link between the Hiatus in Global Warming and North American Drought

2015 ◽  
Vol 28 (9) ◽  
pp. 3834-3845 ◽  
Author(s):  
Thomas L. Delworth ◽  
Fanrong Zeng ◽  
Anthony Rosati ◽  
Gabriel A. Vecchi ◽  
Andrew T. Wittenberg
Keyword(s):  
Global Warming ◽  
North America ◽  
Surface Temperature ◽  
North American ◽  
Radiative Forcing ◽  
Tropical Pacific ◽  
Global Warming Hiatus ◽  
Warming Hiatus ◽  
The Impact ◽  
The Tropical Pacific

Abstract Portions of western North America have experienced prolonged drought over the last decade. This drought has occurred at the same time as the global warming hiatus—a decadal period with little increase in global mean surface temperature. Climate models and observational analyses are used to clarify the dual role of recent tropical Pacific changes in driving both the global warming hiatus and North American drought. When observed tropical Pacific wind stress anomalies are inserted into coupled models, the simulations produce persistent negative sea surface temperature anomalies in the eastern tropical Pacific, a hiatus in global warming, and drought over North America driven by SST-induced atmospheric circulation anomalies. In the simulations herein the tropical wind anomalies account for 92% of the simulated North American drought during the recent decade, with 8% from anthropogenic radiative forcing changes. This suggests that anthropogenic radiative forcing is not the dominant driver of the current drought, unless the wind changes themselves are driven by anthropogenic radiative forcing. The anomalous tropical winds could also originate from coupled interactions in the tropical Pacific or from forcing outside the tropical Pacific. The model experiments suggest that if the tropical winds were to return to climatological conditions, then the recent tendency toward North American drought would diminish. Alternatively, if the anomalous tropical winds were to persist, then the impact on North American drought would continue; however, the impact of the enhanced Pacific easterlies on global temperature diminishes after a decade or two due to a surface reemergence of warmer water that was initially subducted into the ocean interior.

scholarly journals The Influence of Sea Surface Temperatures on the Northern Winter Stratosphere: Ensemble Simulations with the MAECHAM5 Model

2006 ◽  
Vol 19 (16) ◽  
pp. 3863-3881 ◽  
Author(s):  
E. Manzini ◽  
M. A. Giorgetta ◽  
M. Esch ◽  
L. Kornblueh ◽  
E. Roeckner
Keyword(s):  
Lower Stratosphere ◽  
Southern Oscillation ◽  
Internal Variability ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Mean Flow ◽  
Enso Events ◽  
Surface Temperatures ◽  
Northern Winter ◽  
Mean State

Abstract The role of interannual variations in sea surface temperatures (SSTs) on the Northern Hemisphere winter polar stratospheric circulation is addressed by means of an ensemble of nine simulations performed with the middle atmosphere configuration of the ECHAM5 model forced with observed SSTs during the 20-yr period from 1980 to 1999. Results are compared to the 40-yr ECMWF Re-Analysis (ERA-40). Three aspects have been considered: the influence of the interannual SST variations on the climatological mean state, the response to El Niño–Southern Oscillation (ENSO) events, and the influence on systematic temperature changes. The strongest influence of SST variations has been found for the warm ENSO events considered. Namely, it has been found that the large-scale pattern associated with the extratropical tropospheric response to the ENSO phenomenon during northern winter enhances the forcing and the vertical propagation into the stratosphere of the quasi-stationary planetary waves emerging from the troposphere. This enhanced planetary wave disturbance thereafter results in a polar warming of a few degrees in the lower stratosphere in late winter and early spring. Consequently, the polar vortex is weakened, and the warm ENSO influence clearly emerges also in the zonal-mean flow. In contrast, the cold ENSO events considered do not appear to have an influence distinguishable from that of internal variability. It is also not straightforward to deduce the influence of the SSTs on the climatological mean state from the simulations performed, because the simulated internal variability of the stratosphere is large, a realistic feature. Moreover, the results of the ensemble of simulations provide weak to negligible evidence for the possibility that SST variations during the two decades considered are substantially contributing to changes in the polar temperature in the winter lower stratosphere.

scholarly journals Geological Oceanography of the Pliocene Warm Period: A Review with Predictions on the Future of Global Warming

2021 ◽  
Vol 9 (11) ◽  
pp. 1210
Author(s):  
Markes E. Johnson
Keyword(s):  
Global Warming ◽  
Warm Period ◽  
Sea Surface ◽  
Extreme Weather Events ◽  
Temperature Sensitive ◽  
Extensive Literature ◽  
Sea Surface Temperatures ◽  
Storm Events ◽  
Surface Temperatures ◽  
The Future

Atmospheric carbon dioxide reached a record concentration of 419 parts per million in May 2021, 50% higher than preindustrial levels at 280 parts per million. The rise of CO2 as a heat-trapping gas is the principal barometer tracking global warming attributed to a global average increase of 1.2 °C over the last 250 years. Ongoing global warming is expected to perturb extreme weather events such as tropical cyclones (hurricanes/typhoons), strengthened by elevated sea-surface temperatures. The melting of polar ice caps in Antarctica and Greenland also is expected to result in rising sea levels through the rest of this century. Various proxies for the estimate of long-term change in sea-surface temperatures (SSTs) are available through geological oceanography, which relies on the recovery of deep-sea cores for the study of sediments enriched in temperature-sensitive planktonic foraminifera and other algal residues. The Pliocene Warm Period occurred between ~4.5 and 3.0 million years ago, when sea level and average global temperatures were higher than today, and it is widely regarded as a predictive analog to the future impact of climate change. This work reviews some of the extensive literature on the geological oceanography of the Pliocene Warm Period together with a summary of land-based studies in paleotempestology focused on coastal boulder deposits (CBDs) and coastal outwash deposits (CODs) from the margin of the Pacific basin and parts of the North Atlantic basin. Ranging in age from the Pliocene through the Holocene, the values of such deposits serve as fixed geophysical markers, against which the micro-fossil record for the Pliocene Warm Period may be compared, as a registry of storm events from Pliocene and post-Pliocene times.

scholarly journals Reconstructed 3-D Ocean Temperature Derived from Remotely Sensed Sea Surface Measurements for Mixed Layer Depth Analysis

2019 ◽  
Vol 11 (24) ◽  
pp. 3018 ◽  
Author(s):  
Yubeen Jeong ◽  
Jihyun Hwang ◽  
Jinku Park ◽  
Chan Joo Jang ◽  
Young-Heon Jo
Keyword(s):  
Global Warming ◽  
Spatial Resolution ◽  
Linear Trend ◽  
Mixed Layer Depth ◽  
Sea Surface ◽  
Layer Depth ◽  
Thermal Structures ◽  
Global Warming Hiatus ◽  
Surface Measurements ◽  
Warming Hiatus

The mixed layer depth (MLD) is generally estimated using in situ or model data. However, MLD analyses have limitations due to the sparse resolution of the observed data. Therefore, this study reconstructs three-dimensional (3D) ocean thermal structures using only satellite sea surface measurements for a higher spatial and longer temporal resolution than that of Argo and diagnoses the decadal variation of global MLD variability. To simulate the ocean thermal structures, the relationship between the ocean subsurface temperature and the sea surface fields was computed based on gridded Argo data. Based on this relationship, high spatial resolution and extended periods of satellite-derived altimeter, sea surface temperature (SST), and wind stress data were used to estimate the 3D ocean thermal structures with 0.25° spatial resolution and 26 standard depth levels (5–2000 m) for 24 years (1993–2016). Then, the MLD was calculated using a temperature threshold method (∆T = 0.2 °C) and correlated reasonably well (>0.9) with other MLD datasets. The extended 24-year data enabled us to analyze the decadal variability of the MLD. The global linear trend of the 24-year MLD is −0.110 m yr−1; however, from 1998 to 2012, the linear trend is −0.003 m yr−1 which is an order of magnitude smaller than that of other periods and corresponds to a global warming hiatus period. Via comparisons between the trends of the SST anomalies and the MLD anomalies, we tracked how the MLD trend changes in response to the global warming hiatus.

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