Seasonal Forecasts and Water Management in Arizona: A Case Study of the 1997–98 El Niño Event

WRPMD'99 ◽  
1999 ◽  
Author(s):  
Thomas C. Pagano ◽  
Holly C. Hartmann ◽  
Soroosh Sorooshian
2003 ◽  
Vol 16 (19) ◽  
pp. 3153-3170 ◽  
Author(s):  
Frédéric Vitart ◽  
Magdalena Alonso Balmaseda ◽  
Laura Ferranti ◽  
David Anderson

1994 ◽  
Vol 99 (B12) ◽  
pp. 23921-23937 ◽  
Author(s):  
J. O. Dickey ◽  
S. L. Marcus ◽  
R. Hide ◽  
T. M. Eubanks ◽  
D. H. Boggs

Author(s):  
Casey Keat-Chuan Ng ◽  
Choo-Hou Goh ◽  
Jia-Chun Lin ◽  
Minn-Syenn Tan ◽  
Willie Bong ◽  
...  

2019 ◽  
Vol 10 ◽  
Author(s):  
Bruno O. Gimenez ◽  
Kolby J. Jardine ◽  
Niro Higuchi ◽  
Robinson I. Negrón-Juárez ◽  
Israel de Jesus Sampaio-Filho ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diego Páez-Rosas ◽  
Jorge Torres ◽  
Eduardo Espinoza ◽  
Adrian Marchetti ◽  
Harvey Seim ◽  
...  

AbstractCurrently, the Galapagos sea lion (GSL, Zalophus wollebaeki) and Galapagos fur seal (GFS, Arctocephalus galapagoensis) are among the most important endemic species for conservation in the Galapagos Archipelago. Both are classified as “Endangered” since their populations have undergone drastic declines over the last several decades. In this study we estimated the abundance of both otariids, and their population trends based using counts conducted between 2014 and 2018 in all their rookeries, and we analyzed the influence of environmental variability on pup production. The GSL population size in 2018 in the archipelago was estimated to be between 17,000 to 24,000 individuals and has increased at an average annual rate of 1% over the last five years after applying correction factors. The highest number of GSL counted in the archipelago was in 2014 followed by a population decline of 23.8% in 2015 that was associated with the El Niño event that occurred during that year. Following this event, the population increased mainly in the northern, central and southeastern rookeries. The GSL pup abundance showed a decreasing trend with the increase in intensity of the El Niño. The GFS population in 2018 was counted in 3,093 individuals and has increased at an annual rate of 3% from 2014 to 2018. A high number of GFS counted in 2014 was followed by a population decrease of 38% in 2015, mainly in the western rookeries. There was interannual population fluctuations and different growth trends among regions of the archipelago. GSL and GFS pup abundance has a strong decreasing tendency with the increase in the subthermocline temperature (ST) and the El Niño 1 + 2 index. Our results provide evidence that both species are highly vulnerable to periodic oceanographic-atmospheric events in the Galapagos Archipelago which impact prey abundance and the flow of energy in the unique Galapagos ecosystem.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Luyu Chang ◽  
Jianming Xu ◽  
Xuexi Tie ◽  
Jianbin Wu
Keyword(s):  
El Niño ◽  
El Nino ◽  

2018 ◽  
Vol 31 (24) ◽  
pp. 9869-9879 ◽  
Author(s):  
Jianping Duan ◽  
Lun Li ◽  
Zhuguo Ma ◽  
Jan Esper ◽  
Ulf Büntgen ◽  
...  

Large volcanic eruptions may cause abrupt summer cooling over large parts of the globe. However, no comparable imprint has been found on the Tibetan Plateau (TP). Here, we introduce a 400-yr-long temperature-sensitive network of 17 tree-ring maximum latewood density sites from the TP that demonstrates that the effects of tropical eruptions on the TP are generally greater than those of extratropical eruptions. Moreover, we found that large tropical eruptions accompanied by subsequent El Niño events caused less summer cooling than those that occurred without El Niño association. Superposed epoch analysis (SEA) based on 27 events, including 14 tropical eruptions and 13 extratropical eruptions, shows that the summer cooling driven by extratropical eruptions is insignificant on the TP, while significant summer temperature decreases occur subsequent to tropical eruptions. Further analysis of the TP August–September temperature responses reveals a significant postvolcanic cooling only when no El Niño event occurred. However, there is no such cooling for all other situations, that is, tropical eruptions together with a subsequent El Niño event, as well as extratropical eruptions regardless of the occurrence of an El Niño event. The averaged August–September temperature deviation ( Tdev) following 10 large tropical eruptions without a subsequent El Niño event is up to −0.48° ± 0.19°C (with respect to the preceding 5-yr mean), whereas the temperature deviation following 4 large tropical eruptions with an El Niño association is approximately 0.23° ± 0.16°C. These results indicate a mitigation effect of El Niño events on the TP temperature response to large tropical eruptions. The possible mechanism is that El Niño events can weaken the Indian summer monsoon with a subsequent decrease in rainfall and cooling effect, which may lead to a relatively high temperature on the TP, one of the regions affected by the Indian summer monsoon.


Ocean Science ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 187-194 ◽  
Author(s):  
F. Zheng ◽  
J. Zhu

Abstract. The 2006–2007 El Niño event, an unusually weak event, was predicted by most models only after the warming in the eastern Pacific had commenced. In this study, on the basis of an El Niño prediction system, roles of the initial ocean surface and subsurface states on predicting the 2006–2007 El Niño event are investigated to determine conditions favorable for predicting El Niño growth and are isolated in three sets of hindcast experiments. The hindcast is initialized through assimilation of only the sea surface temperature (SST) observations to optimize the initial surface condition, only the sea level (SL) data to update the initial subsurface state, or both the SST and SL data. Results highlight that the hindcasts with three different initial states can all successfully predict the 2006–2007 El Niño event 1 year in advance and that the hindcast initialized by both the SST and SL data performs best. A comparison between the various sets of hindcast results further demonstrates that successful prediction is more significantly affected by the initial subsurface state than by the initial surface condition. The accurate initial surface state can trigger the easier prediction of the 2006–2007 El Niño, whereas a more reasonable initial subsurface state can contribute to improving the prediction in the growth of the warm event.


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