scholarly journals Biogeochemical cycling and phyto- and bacterio-plankton communities in a large and shallow tropical lagoon (Terminos Lagoon, Mexico) under 2009–2010 El Niño Modoki drought conditions

2016 ◽  
Author(s):  
Pascal Conan ◽  
Mireille Pujo-Pay ◽  
Marina Agab ◽  
Laura Calva-Benitez ◽  
Sandrine Chifflet ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bacterial Community ◽  
El Niño ◽  
El Nino ◽  
Organic Phosphorus ◽  
Biogeochemical Cycling ◽  
Large Set ◽  
El Niño Modoki ◽  
Terminos Lagoon ◽  
Plankton Communities

Abstract. A large set of biogeochemical (nutrients, dissolved and particulate organic matter), phytoplanktonic (biomass and photosynthetic activity) and bacterial (bacterial diversity and ectoenzymatic activities) parameters were determined to understand how the severe drought period relative to the 2009–2010 El Niño Modoki episode influenced biogeochemical cycling and phyto- and bacterio-plankton communities in Terminos Lagoon (Mexico) potentially prefiguring future environmental conditions due to expected trends in climate change. During the study period, the water column of Terminos Lagoon functioned globally as a sink, and especially as a "nitrogen assimilator", because of high production of particulate and dissolved organic matter although exportation of autochthonous matter to the Gulf of Mexico was weak. Coupling between top-down and bottom-up controls accounted for the diverse responses in phytoplankton productivity. Nitrogen and phosphorus stoichiometry mostly accounted for the heterogeneity in phytoplankton and bacteria distribution in the lagoon. In the Eastern part, we found a clear decoupling between areas enriched in dissolved inorganic nitrogen in the North close to Puerto real coastal inlet and areas enriched in phosphate (PO4) in the South close to the Candelaria estuary. Such a decoupling limited the potential for primary production resulting in an accumulation of dissolved organic carbon and nitrogen (DOC and DON, respectively) close to the river mouth. In the Western part of the lagoon, maximal phytoplankton development resulted from the coupling between Palizada river inputs of nitrate (NO3) and particulate organic phosphorus -PP- (but depleted in PO4) and bacterial activity transforming PP and dissolved organic phosphorus (DOP) to available PO4. The Chumpan River only marginally contributed to PO4 inputs due to its very low contribution to overall river inputs. We also found that a complex array of biogeochemical and phytoplanktonic parameters were the driving force behind the geographical distribution of bacterial community structure and activities. Finally, we showed that nutrients brought by the Palizada River supported an abundant bacterial community of polycyclic aromatic hydrocarbon (PAH)-degraders, which are of significance in this important oil production zone.

scholarly journals Biogeochemical cycling and phyto- and bacterioplankton communities in a large and shallow tropical lagoon (Términos Lagoon, Mexico) under 2009–2010 El Niño Modoki drought conditions

2017 ◽  
Vol 14 (4) ◽  
pp. 959-975 ◽  
Author(s):  
Pascal Conan ◽  
Mireille Pujo-Pay ◽  
Marina Agab ◽  
Laura Calva-Benítez ◽  
Sandrine Chifflet ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bacterial Community ◽  
Gulf Of Mexico ◽  
El Niño ◽  
El Nino ◽  
Organic Phosphorus ◽  
Phytoplankton Productivity ◽  
El Niño Modoki ◽  
Terminos Lagoon ◽  
Bacterioplankton Communities

Abstract. The 2009–2010 period was marked by an episode of intense drought known as the El Niño Modoki event. Sampling of the Términos Lagoon (Mexico) was carried out in November 2009 in order to understand the influence of these particular environmental conditions on organic matter fluxes within the lagoon's pelagic ecosystem and, more specifically, on the relationship between phyto- and bacterioplankton communities. The measurements presented here concern biogeochemical parameters (nutrients, dissolved and particulate organic matter [POM], and dissolved polycyclic aromatic hydrocarbons [PAHs]), phytoplankton (biomass and photosynthesis), and bacteria (diversity and abundance, including PAH degradation bacteria and ectoenzymatic activities). During the studied period, the water column of the Términos Lagoon functioned globally as a sink and, more precisely, as a nitrogen assimilator. This was due to the high production of particulate and dissolved organic matter (DOM), even though exportation of autochthonous matter to the Gulf of Mexico was weak. We found that bottom-up control accounted for a large portion of the variability of phytoplankton productivity. Nitrogen and phosphorus stoichiometry mostly accounted for the heterogeneity in phytoplankton and free-living prokaryote distribution in the lagoon. In the eastern part, we found a clear decoupling between areas enriched in dissolved inorganic nitrogen near the Puerto Real coastal inlet and areas enriched in phosphate (PO4) near the Candelaria estuary. Such a decoupling limited the potential for primary production, resulting in an accumulation of dissolved organic carbon and nitrogen (DOC and DON, respectively) near the river mouths. In the western part of the lagoon, maximal phytoplankton development resulted from bacterial activity transforming particulate organic phosphorus (PP) and dissolved organic phosphorus (DOP) to available PO4 and the coupling between Palizada River inputs of nitrate (NO3) and PP. The Chumpan River contributed only marginally to PO4 inputs due to its very low contribution to overall river inputs. The highest dissolved total PAH concentrations were measured in the El Carmen Inlet, suggesting that the anthropogenic pollution of the zone is probably related to the oil-platform exploitation activities in the shallow waters of the southern of the Gulf of Mexico. We also found that a complex array of biogeochemical and phytoplanktonic parameters were the driving force behind the geographical distribution of bacterial community structure and activities. Finally, we showed that nutrients brought by the Palizada River supported an abundant bacterial community of PAH degraders, which are of significance in this important oil-production zone.

scholarly journals The Response of Tropical Atmospheric Energy Budgets to ENSO*

2013 ◽  
Vol 26 (13) ◽  
pp. 4710-4724 ◽  
Author(s):  
Michael Mayer ◽  
Kevin E. Trenberth ◽  
Leopold Haimberger ◽  
John T. Fasullo
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Warm Pool ◽  
Smooth Transition ◽  
Energy Budgets ◽  
Enso Events ◽  
El Niño Modoki ◽  
Static Energy ◽  
The Tropics

Abstract The variability of zonally resolved tropical energy budgets in association with El Niño–Southern Oscillation (ENSO) is investigated. The most recent global atmospheric reanalyses from 1979 to 2011 are employed with removal of apparent discontinuities to obtain best possible temporal homogeneity. The growing length of record allows a more robust analysis of characteristic patterns of variability with cross-correlation, composite, and EOF methods. A quadrupole anomaly pattern is found in the vertically integrated energy divergence associated with ENSO, with centers over the Indian Ocean, the Indo-Pacific warm pool, the eastern equatorial Pacific, and the Atlantic. The smooth transition, particularly of the main maxima of latent and dry static energy divergence, from the western to the eastern Pacific is found to require at least two EOFs to be adequately described. The canonical El Niño pattern (EOF-1) and a transition pattern (EOF-2; referred to as El Niño Modoki by some authors) form remarkably coherent ENSO-related anomaly structures of the tropical energy budget not only over the Pacific but throughout the tropics. As latent and dry static energy divergences show strong mutual cancellation, variability of total energy divergence is smaller and more tightly coupled to local sea surface temperature (SST) anomalies and is mainly related to the ocean heat discharge and recharge during ENSO peak phases. The complexity of the structures throughout the tropics and their evolution during ENSO events along with their interactions with the annual cycle have often not been adequately accounted for; in particular, the El Niño Modoki mode is but part of the overall evolutionary patterns.

The El Niño Modoki

2021 ◽  
pp. 93-114
Author(s):  
Shamal Marathe ◽  
Ashok Karumuri
Keyword(s):  
El Niño ◽  
El Nino ◽  
El Niño Modoki

scholarly journals Reintensification of the Anomalous Western North Pacific Anticyclone during the El Niño Modoki Decaying Summer: Relative Importance of Tropical Atlantic and Pacific SST Anomalies

2020 ◽  
Vol 33 (8) ◽  
pp. 3271-3288
Author(s):  
Juan Feng ◽  
Wen Chen ◽  
Xiaocong Wang
Keyword(s):  
El Niño ◽  
North Pacific ◽  
General Circulation ◽  
Western North Pacific ◽  
El Nino ◽  
Central Pacific ◽  
El Niño Modoki ◽  
Sst Cooling ◽  
Sst Warming ◽  
Sst Anomalies

AbstractThe El Niño Modoki–induced anomalous western North Pacific anticyclone (WNPAC) undergoes an interesting reintensification process in the El Niño Modoki decaying summer, the period when El Niño Modoki decays but warm sea surface temperature (SST) anomalies over the tropical North Atlantic (TNA) and cold SST anomalies over the central-eastern Pacific (CEP) dominate. In this study, the region (TNA or CEP) in which the SST anomalies exert a relatively important influence on reintensification of the WNPAC is investigated. Observational analysis demonstrates that when only anomalous CEP SST cooling occurs, the WNPAC experiences a weak reintensification. In contrast, when only anomalous TNA SST warming emerges, the WNPAC experiences a remarkable reintensification. Numerical simulation analysis demonstrates that even though the same magnitude of CEP SST cooling and TNA warming is respectively set to force the atmospheric general circulation model, the response of the WNPAC is still much stronger in the TNA warming experiment than in the CEP cooling experiment. Further analysis demonstrates that this difference is caused by the distinct location of the effective tropical forcing between the CEP SST cooling and TNA SST warming for producing a WNPAC. The CEP cooling-induced effective anomalous diabatic cooling is located in the central Pacific, by which the forced anticyclone becomes gradually weak from the central Pacific to the western North Pacific. Thus, a weak WNPAC is produced. In contrast, as the TNA SST warming–induced effective anomalous diabatic cooling is just located in the western North Pacific via a Kelvin wave–induced Ekman divergence process, the forced anticyclone is significant and powerful in the western North Pacific.

scholarly journals The roles of tropical and subtropical wind stress anomalies in the El Niño Modoki onset

2018 ◽  
Vol 52 (11) ◽  
pp. 6585-6597 ◽  
Author(s):  
Xin Wang ◽  
Chengyang Guan ◽  
Rui Xin Huang ◽  
Wei Tan ◽  
Lei Wang
Keyword(s):  
Wind Stress ◽  
El Niño ◽  
El Nino ◽  
El Niño Modoki

Predictability of the Super IOD Event in 2019 and Its Link With El Niño Modoki

2020 ◽  
Vol 47 (7) ◽  
Author(s):  
Takeshi Doi ◽  
Swadhin K. Behera ◽  
Toshio Yamagata
Keyword(s):  
El Niño ◽  
El Nino ◽  
El Niño Modoki

Climate Dynamics of ENSO Modoki Phenomena

2018 ◽  
Author(s):  
Swadhin Behera ◽  
Toshio Yamagata
Keyword(s):  
El Niño ◽  
El Nino ◽  
Walker Circulation ◽  
The United States ◽  
La Niña ◽  
Central Pacific ◽  
El Niño Modoki ◽  
Enso Modoki ◽  
La Nina ◽  
Sst Anomalies

The El Niño Modoki/La Niña Modoki (ENSO Modoki) is a newly acknowledged face of ocean-atmosphere coupled variability in the tropical Pacific Ocean. The oceanic and atmospheric conditions associated with the El Niño Modoki are different from that of canonical El Niño, which is extensively studied for its dynamics and worldwide impacts. A typical El Niño event is marked by a warm anomaly of sea surface temperature (SST) in the equatorial eastern Pacific. Because of the associated changes in the surface winds and the weakening of coastal upwelling, the coasts of South America suffer from widespread fish mortality during the event. Quite opposite of this characteristic change in the ocean condition, cold SST anomalies prevail in the eastern equatorial Pacific during the El Niño Modoki events, but with the warm anomalies intensified in the central Pacific. The boreal winter condition of 2004 is a typical example of such an event, when a tripole pattern is noticed in the SST anomalies; warm central Pacific flanked by cold eastern and western regions. The SST anomalies are coupled to a double cell in anomalous Walker circulation with rising motion in the central parts and sinking motion on both sides of the basin. This is again a different feature compared to the well-known single-cell anomalous Walker circulation during El Niños. La Niña Modoki is the opposite phase of the El Niño Modoki, when a cold central Pacific is flanked by warm anomalies on both sides.The Modoki events are seen to peak in both boreal summer and winter and hence are not seasonally phase-locked to a single seasonal cycle like El Niño/La Niña events. Because of this distinction in the seasonality, the teleconnection arising from these events will vary between the seasons as teleconnection path will vary depending on the prevailing seasonal mean conditions in the atmosphere. Moreover, the Modoki El Niño/La Niña impacts over regions such as the western coast of the United States, the Far East including Japan, Australia, and southern Africa, etc., are opposite to those of the canonical El Niño/La Niña. For example, the western coasts of the United States suffer from severe droughts during El Niño Modoki, whereas those regions are quite wet during El Niño. The influences of Modoki events are also seen in tropical cyclogenesis, stratosphere warming of the Southern Hemisphere, ocean primary productivity, river discharges, sea level variations, etc. A remarkable feature associated with Modoki events is the decadal flattening of the equatorial thermocline and weakening of zonal thermal gradient. The associated ocean-atmosphere conditions have caused frequent and persistent developments of Modoki events in recent decades.

scholarly journals The relative impacts of El Niño Modoki, canonical El Niño, and QBO on tropical ozone changes since the 1980s

2014 ◽  
Vol 9 (6) ◽  
pp. 064020 ◽  
Author(s):  
Fei Xie ◽  
Jianping Li ◽  
Wenshou Tian ◽  
Jiankai Zhang ◽  
Cheng Sun
Keyword(s):  
El Niño ◽  
El Nino ◽  
El Niño Modoki
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