El Nino-Like Pattern in Ice Age Tropical Pacific Sea Surface Temperature

Science ◽  
2002 ◽  
Vol 297 (5579) ◽  
pp. 226-230 ◽  
Author(s):  
A. Koutavas
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jialin Lin ◽  
Taotao Qian

AbstractThe El Nino-Southern Oscillation (ENSO) is the dominant interannual variability of Earth’s climate system and plays a central role in global climate prediction. Outlooks of ENSO and its impacts often follow a two-tier approach: predicting ENSO sea surface temperature anomaly in tropical Pacific and then predicting its global impacts. However, the current picture of ENSO global impacts widely used by forecasting centers and atmospheric science textbooks came from two earliest surface station datasets complied 30 years ago, and focused on the extreme phases rather than the whole ENSO lifecycle. Here, we demonstrate a new picture of the global impacts of ENSO throughout its whole lifecycle based on the rich latest satellite, in situ and reanalysis datasets. ENSO impacts are much wider than previously thought. There are significant impacts unknown in the previous picture over Europe, Africa, Asia and North America. The so-called “neutral years” are not neutral, but are associated with strong sea surface temperature anomalies in global oceans outside the tropical Pacific, and significant anomalies of land surface air temperature and precipitation over all the continents.


2014 ◽  
Vol 27 (22) ◽  
pp. 8413-8421 ◽  
Author(s):  
Lei Zhang ◽  
Tim Li

Abstract How sea surface temperature (SST) changes under global warming is critical for future climate projection because SST change affects atmospheric circulation and rainfall. Robust features derived from 17 models of phase 5 of the Coupled Model Intercomparison Project (CMIP5) include a much greater warming in high latitudes than in the tropics, an El Niño–like warming over the tropical Pacific and Atlantic, and a dipole pattern in the Indian Ocean. However, the physical mechanism responsible for formation of such warming patterns remains open. A simple theoretical model is constructed to reveal the cause of the future warming patterns. The result shows that a much greater polar, rather than tropical, warming depends primarily on present-day mean SST and surface latent heat flux fields, and atmospheric longwave radiation feedback associated with cloud change further enhances this warming contrast. In the tropics, an El Niño–like warming over the Pacific and Atlantic arises from a similar process, while cloud feedback resulting from different cloud regimes between east and west ocean basins also plays a role. A dipole warming over the equatorial Indian Ocean is a response to weakened Walker circulation in the tropical Pacific.


2015 ◽  
Vol 28 (8) ◽  
pp. 3133-3151 ◽  
Author(s):  
Christine T. Y. Chung ◽  
Scott B. Power

Abstract El Niño–Southern Oscillation strongly influences the interannual variability of rainfall over the Pacific, shifting the position and orientation of the South Pacific convergence zone (SPCZ) and intertropical convergence zone (ITCZ). In 1982/83 and 1997/98, very strong El Niño events occurred, during which time the SPCZ and ITCZ merged into a single zonal convergence zone (szCZ) extending across the Pacific at approximately 5°S. The sea surface temperature anomalies (SSTAs) reached very large values and peaked farther east compared to other El Niño events. Previous work shows that tropical Pacific precipitation responds nonlinearly to changing the amplitude of the El Niño SSTA even if the structure of the SSTA remains unchanged, but large canonical El Niño SSTAs cannot reproduce the szCZ precipitation pattern. This study conducts idealized, SST-forced experiments, starting with a large-amplitude canonical El Niño SSTA and gradually adding a residual pattern until the full (1982/83) and (1997/98) mean SST is reproduced. Differences between the canonical and strong El Niño SSTA patterns are crucial in generating an szCZ event. Three elements influence the precipitation pattern: (i) the local meridional SST maxima influences the ITCZ position and western Pacific precipitation, (ii) the total zonal SST maximum influences the SPCZ position, and (iii) the equatorial Pacific SST influences the total amount of precipitation. In these experiments, the meridional SST gradient increases as the SSTAs approach szCZ conditions. Additionally, the precipitation changes evident in szCZ years are primarily driven by changes in the atmospheric circulation, rather than thermodynamic changes. The addition of a global warming SST pattern increases the precipitation along the equator and shifts the ITCZ farther equatorward.


2000 ◽  
Vol 203 (15) ◽  
pp. 2311-2322 ◽  
Author(s):  
B. Culik ◽  
J. Hennicke ◽  
T. Martin

We satellite-tracked five Humboldt penguins during the strong 1997/98 El Nino Southern Oscillation (ENSO) from their breeding island Pan de Azucar (26 degrees 09′S, 70 degrees 40′W) in Northern Chile and related their activities at sea to satellite-derived information on sea surface temperature (SST), sea surface temperature anomaly (SSTA), wind direction and speed, chlorophyll a concentrations and statistical data on fishery landings. We found that Humboldt penguins migrated by up to 895 km as marine productivity decreased. The total daily dive duration was highly correlated with SSTA, ranging from 3.1 to 12.5 h when the water was at its warmest (+4 degrees C). Birds travelled between 2 and 116 km every day, travelling further when SSTA was highest. Diving depths (maximum 54 m), however, were not increased with respect to previous years. Two penguins migrated south and, independently of each other, located an area of high chlorophyll a concentration 150 km off the coast. Humboldt penguins seem to use day length, temperature gradients, wind direction and olfaction to adapt to changing environmental conditions and to find suitable feeding grounds. This makes Humboldt penguins biological in situ detectors of highly productive marine areas, with a potential use in the verification of trends detected by remote sensors on board satellites.


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