scholarly journals Multidecadal variations of Fremantle sea level: Footprint of climate variability in the tropical Pacific

2004 ◽  
Vol 31 (16) ◽  
Author(s):  
Ming Feng
Keyword(s):  
Climate Variability ◽  
Sea Level ◽  
Tropical Pacific ◽  
The Tropical Pacific

scholarly journals Tropical Pacific spatial trend patterns in observed sea level: internal variability and/or anthropogenic signature?

2012 ◽  
Vol 8 (2) ◽  
pp. 787-802 ◽  
Author(s):  
B. Meyssignac ◽  
D. Salas y Melia ◽  
M. Becker ◽  
W. Llovel ◽  
A. Cazenave
Keyword(s):  
Sea Level ◽  
Climate Models ◽  
Internal Variability ◽  
Tropical Pacific ◽  
External Forcing ◽  
Spatial Trend ◽  
Trend Pattern ◽  
Coupled Climate Models ◽  
Sea Level Trend ◽  
The Tropical Pacific

Abstract. In this study we focus on the sea level trend pattern observed by satellite altimetry in the tropical Pacific over the 1993–2009 time span (i.e. 17 yr). Our objective is to investigate whether this 17-yr-long trend pattern was different before the altimetry era, what was its spatio-temporal variability and what have been its main drivers. We try to discriminate the respective roles of the internal variability of the climate system and of external forcing factors, in particular anthropogenic emissions (greenhouse gases and aerosols). On the basis of a 2-D past sea level reconstruction over 1950–2009 (based on a combination of observations and ocean modelling) and multi-century control runs (i.e. with constant, preindustrial external forcing) from eight coupled climate models, we have investigated how the observed 17-yr sea level trend pattern evolved during the last decades and centuries, and try to estimate the characteristic time scales of its variability. For that purpose, we have computed sea level trend patterns over successive 17-yr windows (i.e. the length of the altimetry record), both for the 60-yr long reconstructed sea level and the model runs. We find that the 2-D sea level reconstruction shows spatial trend patterns similar to the one observed during the altimetry era. The pattern appears to have fluctuated with time with a characteristic time scale of the order of 25–30 yr. The same behaviour is found in multi-centennial control runs of the coupled climate models. A similar analysis is performed with 20th century coupled climate model runs with complete external forcing (i.e. solar plus volcanic variability and changes in anthropogenic forcing). Results suggest that in the tropical Pacific, sea level trend fluctuations are dominated by the internal variability of the ocean–atmosphere coupled system. While our analysis cannot rule out any influence of anthropogenic forcing, it concludes that the latter effect in that particular region is stillhardly detectable.

scholarly journals Decadal Sea Level Variability in the Pacific Ocean: Origins and Climate Mode Contributions

2019 ◽  
Vol 36 (4) ◽  
pp. 689-698 ◽  
Author(s):  
Lingsheng Meng ◽  
Wei Zhuang ◽  
Weiwei Zhang ◽  
Angela Ditri ◽  
Xiao-Hai Yan
Keyword(s):  
Pacific Ocean ◽  
Sea Level ◽  
Time Scales ◽  
Wind Stress ◽  
Tropical Pacific ◽  
Central Basin ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Sea Level Variations ◽  
The Tropical Pacific

AbstractSea level changes within wide temporal–spatial scales have great influence on oceanic and atmospheric circulations. Efforts have been made to identify long-term sea level trend and regional sea level variations on different time scales. A nonuniform sea level rise in the tropical Pacific and the strengthening of the easterly trade winds from 1993 to 2012 have been widely reported. It is well documented that sea level in the tropical Pacific is associated with the typical climate modes. However, sea level change on interannual and decadal time scales still requires more research. In this study, the Pacific sea level anomaly (SLA) was decomposed into interannual and decadal time scales via an ensemble empirical mode decomposition (EEMD) method. The temporal–spatial features of the SLA variability in the Pacific were examined and were closely associated with climate variability modes. Moreover, decadal SLA oscillations in the Pacific Ocean were identified during 1993–2016, with the phase reversals around 2000, 2004, and 2012. In the tropical Pacific, large sea level variations in the western and central basin were a result of changes in the equatorial wind stress. Moreover, coherent decadal changes could also be seen in wind stress, sea surface temperature (SST), subtropical cells (STCs), and thermocline depth. Our work provided a new way to illustrate the interannual and decadal sea level variations in the Pacific Ocean and suggested a coupled atmosphere–ocean variability on a decadal time scale in the tropical region with two cycles from 1993 to 2016.

scholarly journals Future extreme sea level seesaws in the tropical Pacific

2015 ◽  
Vol 1 (8) ◽  
pp. e1500560 ◽  
Author(s):  
Matthew J. Widlansky ◽  
Axel Timmermann ◽  
Wenju Cai
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
El Niño ◽  
El Nino ◽  
Tropical Pacific ◽  
Greenhouse Warming ◽  
Mean Sea Level ◽  
Global Mean Sea Level ◽  
Global Mean ◽  
The Tropical Pacific

Global mean sea levels are projected to gradually rise in response to greenhouse warming. However, on shorter time scales, modes of natural climate variability in the Pacific, such as the El Niño–Southern Oscillation (ENSO), can affect regional sea level variability and extremes, with considerable impacts on coastal ecosystems and island nations. How these shorter-term sea level fluctuations will change in association with a projected increase in extreme El Niño and its atmospheric variability remains unknown. Using present-generation coupled climate models forced with increasing greenhouse gas concentrations and subtracting the effect of global mean sea level rise, we find that climate change will enhance El Niño–related sea level extremes, especially in the tropical southwestern Pacific, where very low sea level events, locally known as Taimasa, are projected to double in occurrence. Additionally, and throughout the tropical Pacific, prolonged interannual sea level inundations are also found to become more likely with greenhouse warming and increased frequency of extreme La Niña events, thus exacerbating the coastal impacts of the projected global mean sea level rise.

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