scholarly journals The Role of Ocean Dynamical Thermostat in Delaying the El Niño–Like Response over the Equatorial Pacific to Climate Warming

2017 ◽  
Vol 30 (8) ◽  
pp. 2811-2827 ◽  
Author(s):  
Yiyong Luo ◽  
Jian Lu ◽  
Fukai Liu ◽  
Oluwayemi Garuba
Keyword(s):  
Climate Warming ◽  
El Niño ◽  
El Nino ◽  
Heat Budget ◽  
Equatorial Pacific ◽  
Ocean Dynamics ◽  
Trade Wind ◽  
Equatorial Pacific Ocean ◽  
Budget Analysis

The role of ocean dynamics in the response of the equatorial Pacific Ocean to climate warming is investigated using both an atmosphere–ocean coupled climate system and its ocean component. Results show that the initial response (fast pattern) to an uniform heating imposed on the ocean is a warming centered to the west of the date line owing to the conventional ocean dynamical thermostat (ODT) mechanism in the eastern equatorial Pacific—a cooling effect arising from the up-gradient upwelling. In time, the warming pattern gradually propagates eastward, becoming more El Niño–like (slow pattern). The transition from the fast to the slow pattern likely results from 1) the gradual warming of the equatorial thermocline temperature, which is associated with the arrival of the relatively warmer extratropical waters advected along the subsurface branch of the subtropical cells (STCs), and 2) the reduction of the STC strength itself. A mixed layer heat budget analysis finds that it is the total ocean dynamical effect rather than the conventional ODT that holds the key for understanding the pattern of the SST in the equatorial Pacific and that the surface heat flux works mainly to compensate the ocean dynamics. Further passive tracer experiments with the ocean component of the coupled system verify the role of the ocean dynamical processes in initiating a La Niña–like SST warming and in setting the pace of the transition to an El Niño–like warming and identify an oceanic origin for the slow eastern Pacific warming independent of the weakening trade wind.

scholarly journals Do CMIP5 Models Show El Niño Diversity?

2020 ◽  
Vol 33 (5) ◽  
pp. 1619-1641 ◽  
Author(s):  
Jie Feng ◽  
Tao Lian ◽  
Jun Ying ◽  
Junde Li ◽  
Gen Li
Keyword(s):  
El Niño ◽  
El Nino ◽  
Heat Budget ◽  
Equatorial Pacific ◽  
Cmip5 Models ◽  
Budget Analysis ◽  
Future Global Warming ◽  
Central Equatorial Pacific ◽  
The Future ◽  
Sst Gradient

AbstractWhether the state-of-the-art CMIP5 models have different El Niño types and how the degree of modeled El Niño diversity would be impacted by the future global warming are still heavily debated. In this study, cluster analysis is used to investigate El Niño diversity in 30 CMIP5 models. As the method does not rely on any prior knowledge of the patterns of El Niño seen in observations, it provides a practical way to identify the degree of El Niño diversity in models. Under the historical scenario, most models show a poor degree of El Niño diversity in their own model world, primarily due to the lopsided numbers of events belonging to the two modeled El Niño types and the weak compactness of events in each cluster. Four models are found showing significant El Niño diversity, yet none of them captures the longitudinal distributions of the warming centers of the two El Niño types seen in the observations. Heat budget analysis of the sea surface temperature (SST) anomaly suggests that the degree of modeled El Niño diversity is highly related to the climatological zonal SST gradient over the western-central equatorial Pacific in models. As the gradient is weakened in most models under the future high-emission scenario, the degree of modeled El Niño diversity is further reduced in the future. The results indicate that a better simulation of the SST gradient over the western-central equatorial Pacific might allow a more reliable simulation/projection of El Niño diversity in most CMIP5 models.

Sensitivity of Subsurface Processes of Equatorial Pacific Ocean to the Heat and Momentum Fluxes: A Case Study of 1997-98 El Niño

2020 ◽  
Vol 89 (sp1) ◽  
pp. 26
Author(s):  
Karmakar Ananya ◽  
Parekh Anant ◽  
Jasti Sriranga Chowdary ◽  
Chellappan Gnanaseelan
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Equatorial Pacific ◽  
Equatorial Pacific Ocean ◽  
Momentum Fluxes

scholarly journals Distinguishing Characteristics of Spring and Summer Onset El Niño Events

2020 ◽  
Vol 33 (11) ◽  
pp. 4579-4597
Author(s):  
Hua Xu ◽  
Jianjun Xu ◽  
Chunlei Liu ◽  
Niansen Ou
Keyword(s):  
Zonal Wind ◽  
El Niño ◽  
El Nino ◽  
Heat Budget ◽  
Onset Time ◽  
Bjerknes Feedback ◽  
Budget Analysis ◽  
Basin Scale ◽  
El Niño Events ◽  
El Nino Events

AbstractEl Niño events can be classified into two categories according to the onset time: the spring (SP) El Niño with onset time from April to June and the summer (SU) El Niño with onset time from July to October. The SP El Niño is a basin-scale phenomenon and is closer to the conventional ENSO. It goes through the earlier and stronger heat build-up process, and the earlier occurrence of westerlies in the equatorial Pacific, which can partly explain its earlier onset time. For SU El Niño, in contrast, the anomalous signals, such as SSTAs, zonal wind anomalies, and subsurface variations, are much weaker, which can be attributed to the weaker accumulation of warm water and shorter duration of positive Bjerknes feedback. During its peak phase, anomalous southeasterlies over the eastern Pacific enhance the wind–evaporation–SST (WES) feedback and impede the development of positive SSTAs there, and then lead to a west shift of SSTA center. Recharge/discharge processes exist in both types of events but are weaker in the SU type, which may be caused by the lack of meridional Sverdrup transports as a result of weak zonal wind anomalies. A heat budget analysis demonstrates that the relative importance of thermocline (TH) and zonal advective (ZA) feedbacks in SP and SU El Niño is different. In SP El Niño, the TH feedback is dominant compared to ZA feedback in both the GODAS and SODA datasets. In SU El Niño, however, these two terms are equally important in GODAS, but not in the SODA dataset.

Biological response to the 1997-98 and 2009-10 El Niño events in the equatorial Pacific Ocean

2012 ◽  
Vol 39 (10) ◽  
pp. n/a-n/a ◽  
Author(s):  
Michelle M. Gierach ◽  
Tong Lee ◽  
Daniela Turk ◽  
Michael J. McPhaden
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Biological Response ◽  
Equatorial Pacific ◽  
Equatorial Pacific Ocean ◽  
El Niño Events ◽  
El Nino Events

scholarly journals Implications of changing El Niño patterns for biological dynamics in the equatorial Pacific Ocean

2011 ◽  
Vol 38 (23) ◽  
pp. n/a-n/a ◽  
Author(s):  
D. Turk ◽  
C. S. Meinen ◽  
D. Antoine ◽  
M. J. McPhaden ◽  
M. R. Lewis
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Equatorial Pacific ◽  
Equatorial Pacific Ocean ◽  
Biological Dynamics

scholarly journals Upper equatorial Pacific Ocean current and salinity variability during the 1996-1998 El Niño-La Niña cycle

2000 ◽  
Vol 105 (C1) ◽  
pp. 1037-1053 ◽  
Author(s):  
Gregory C. Johnson ◽  
Michael J. McPhaden ◽  
G. Dail Rowe ◽  
Kristene E. McTaggart
Keyword(s):  
Pacific Ocean ◽  
El Niño ◽  
El Nino ◽  
Equatorial Pacific ◽  
La Niña ◽  
Ocean Current ◽  
Equatorial Pacific Ocean ◽  
La Nina ◽  
Salinity Variability

scholarly journals Nuclear Niño response observed in simulations of nuclear war scenarios

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Joshua Coupe ◽  
Samantha Stevenson ◽  
Nicole S. Lovenduski ◽  
Tyler Rohr ◽  
Cheryl S. Harrison ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Equatorial Pacific ◽  
Climate Impacts ◽  
Food Sources ◽  
Trade Wind ◽  
Nuclear War ◽  
Crop Failure ◽  
Phytoplankton Productivity ◽  
Global Cooling

AbstractThe climate impacts of smoke from fires ignited by nuclear war would include global cooling and crop failure. Facing increased reliance on ocean-based food sources, it is critical to understand the physical and biological state of the post-war oceans. Here we use an Earth system model to simulate six nuclear war scenarios. We show that global cooling can generate a large, sustained response in the equatorial Pacific, resembling an El Niño but persisting for up to seven years. The El Niño following nuclear war, or Nuclear Niño, would be characterized by westerly trade wind anomalies and a shutdown of equatorial Pacific upwelling, caused primarily by cooling of the Maritime Continent and tropical Africa. Reduced incident sunlight and ocean circulation changes would cause a 40% reduction in equatorial Pacific phytoplankton productivity. These results indicate nuclear war could trigger extreme climate change and compromise food security beyond the impacts of crop failure.

scholarly journals Mammalia, Carnivora, Otariidae, Arctocephalus galapagoensis Heller, 1904: first continental record for Costa Rica

Check List ◽  
2010 ◽  
Vol 6 (4) ◽  
pp. 630 ◽  
Author(s):  
Andrea Montero-Cordero ◽  
Damián Martínez Fernández ◽  
Gabriela Hernández-Mora
Keyword(s):  
Costa Rica ◽  
El Niño ◽  
El Nino ◽  
First Record ◽  
Costa Rican ◽  
Equatorial Pacific ◽  
Equatorial Pacific Ocean ◽  
Eastern Equatorial Pacific ◽  
Fur Seal ◽  
Eastern Equatorial Pacific Ocean

This is the first record of Arctocephalus galapagoensis for the mainland coast of Costa Rica, which is outside the geographical distribution of this species about 1,300 km from its type locality. Changes in environmental conditions during El Niño events might be responsible for a higher incidence of these sightings. The presence of a moderate El Niño along the central and eastern equatorial Pacific Ocean during this month coincides with the occurrence of the fur seal in Costa Rican coasts. No photo record had ever been registered before for this country.

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