scholarly journals Global Disease Outbreaks Associated with the 2015–2016 El Niño Event

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Assaf Anyamba ◽  
Jean-Paul Chretien ◽  
Seth C. Britch ◽  
Radina P. Soebiyanto ◽  
Jennifer L. Small ◽  
...  
Keyword(s):  
Southeast Asia ◽  
El Niño ◽  
Land Surface ◽  
El Nino ◽  
Southern Oscillation ◽  
Disease Outbreaks ◽  
Health Concern ◽  
Satellite Monitoring ◽  
Valley Fever ◽  
El Niño Event

Abstract Interannual climate variability patterns associated with the El Niño-Southern Oscillation phenomenon result in climate and environmental anomaly conditions in specific regions worldwide that directly favor outbreaks and/or amplification of variety of diseases of public health concern including chikungunya, hantavirus, Rift Valley fever, cholera, plague, and Zika. We analyzed patterns of some disease outbreaks during the strong 2015–2016 El Niño event in relation to climate anomalies derived from satellite measurements. Disease outbreaks in multiple El Niño-connected regions worldwide (including Southeast Asia, Tanzania, western US, and Brazil) followed shifts in rainfall, temperature, and vegetation in which both drought and flooding occurred in excess (14–81% precipitation departures from normal). These shifts favored ecological conditions appropriate for pathogens and their vectors to emerge and propagate clusters of diseases activity in these regions. Our analysis indicates that intensity of disease activity in some ENSO-teleconnected regions were approximately 2.5–28% higher during years with El Niño events than those without. Plague in Colorado and New Mexico as well as cholera in Tanzania were significantly associated with above normal rainfall (p < 0.05); while dengue in Brazil and southeast Asia were significantly associated with above normal land surface temperature (p < 0.05). Routine and ongoing global satellite monitoring of key climate variable anomalies calibrated to specific regions could identify regions at risk for emergence and propagation of disease vectors. Such information can provide sufficient lead-time for outbreak prevention and potentially reduce the burden and spread of ecologically coupled diseases.

The 2015/16 “Super” El Niño Event and Its Climatic Impact

2017 ◽  
Vol 05 (03) ◽  
pp. 1750017 ◽  
Author(s):  
Bing ZHOU ◽  
Xie SHAO
Keyword(s):  
Surface Temperature ◽  
El Niño ◽  
Land Surface ◽  
El Nino ◽  
Thermal Capacity ◽  
Time Interval ◽  
Equatorial Pacific Ocean ◽  
Climatic Impact ◽  
El Niño Event ◽  
Super El Niño

Climatic monitoring shows that 2015 has been the warmest year around the globe since the first modern observation was conducted in1880. Asia has witnessed its average land surface temperature reaching the highest level since 1901; China has seen the warmest year since 1951 when it had completed the meteorological records; the CO2 concentration in the atmosphere exceeds 400[Formula: see text]ppm; the ocean thermal capacity sets a new record high; and the global sea surface temperature has also been the highest since 1870. Against the backdrop of global warming, the incidence of strong El Niño and the duration of El Niño in the central and eastern equatorial Pacific Ocean have both significantly increased, while the time interval between El Niño and La Niña has shortened. The 2015/16 “Super” El Niño event exceeds previous two “Super” El Niño events in several indexes (e.g. durative event and peak intensity), although the 1982/83 El Niño event keeps the record in terms of the intensity of atmospheric response to the ocean. Influenced by the 2015/16 “Super” El Niño event, the general atmospheric circulation was significantly abnormal with extreme climate events frequently occurring in many places worldwide.

scholarly journals On the progress of the 2015–2016 El Niño event

2016 ◽  
Vol 16 (4) ◽  
pp. 2007-2011 ◽  
Author(s):  
Costas A. Varotsos ◽  
Chris G. Tzanis ◽  
Nicholas V. Sarlis
Keyword(s):  
Time Series ◽  
El Niño ◽  
Southern Oscillation Index ◽  
El Nino ◽  
Southern Oscillation ◽  
Linear Dynamics ◽  
El Niño Event ◽  
Non Linear ◽  
El Niño Events ◽  
Index Time Series

Abstract. It has been recently reported that the current 2015–2016 El Niño could become "one of the strongest on record". To further explore this claim, we performed the new analysis described in detail in Varotsos et al. (2015) that allows the detection of precursory signals of the strong El Niño events by using a recently developed non-linear dynamics tool. In this context, the analysis of the Southern Oscillation Index time series for the period 1876–2015 shows that the running 2015–2016 El Niño would be rather a "moderate to strong" or even a "strong" event and not “one of the strongest on record", as that of 1997–1998.

scholarly journals ENSO and IOD teleconnections for African ecosystems: evidence of destructive interference between climate oscillations

2011 ◽  
Vol 8 (1) ◽  
pp. 27-40 ◽  
Author(s):  
C. A. Williams ◽  
N. P. Hanan
Keyword(s):  
El Niño ◽  
Land Surface ◽  
Vegetation Change ◽  
El Nino ◽  
Southern Oscillation ◽  
Regional Scale ◽  
Interactive Effects ◽  
Surface Model ◽  
Destructive Interference ◽  
Climate Oscillations

Abstract. Rainfall and vegetation across Africa are known to resonate with the coupled ocean-atmosphere phenomena of El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). However, the regional-scale implications of sea surface temperature variability for Africa's photosyntheis have received little focused attention, particularly in the case of IOD. Furthermore, studies exploring the interactive effects of ENSO and IOD when coincident are lacking. This analysis uses remotely sensed vegetation change plus a land surface model driven with observed meteorology to investigate how rainfall, vegetation, and photosynthesis across Africa respond to these climate oscillations. In addition to the relatively well-known ENSO forcing, the IOD induces large departures of photosynthesis across much of Africa associated with anomalies in rainfall and vegetation greenness. More importantly, sizeable independent effects can be suppressed or even reversed by destructive interferences during periods of simultaneous ENSO and IOD activity. For example, effects of positive IOD on southeastern Africa tended to dominate those of El Niño during their coincidence spanning 1997–1998, with sign reversal of El Niño's typically strong suppression of photosynthesis in this region. These findings call into question past analyses examining teleconnections to ENSO or IOD in isolation, and indicate the need to consider their simultaneous states when examining influences on hydroclimatic and ecological conditions across Africa.

scholarly journals Land use change and El Niño-Southern Oscillation drive decadal carbon balance shifts in Southeast Asia

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Masayuki Kondo ◽  
Kazuhito Ichii ◽  
Prabir K. Patra ◽  
Joseph G. Canadell ◽  
Benjamin Poulter ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Southeast Asia ◽  
El Niño ◽  
Carbon Balance ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation

scholarly journals ENSO and IOD teleconnections for African ecosystems: evidence of destructive interference between climate oscillations

2010 ◽  
Vol 7 (4) ◽  
pp. 6323-6352
Author(s):  
C. A. Williams ◽  
N. P. Hanan
Keyword(s):  
El Niño ◽  
Land Surface ◽  
Vegetation Change ◽  
El Nino ◽  
Southern Oscillation ◽  
Regional Scale ◽  
Interactive Effects ◽  
Surface Model ◽  
Destructive Interference ◽  
Climate Oscillations

Abstract. Rainfall and vegetation across Africa are known to resonate with the coupled ocean-atmosphere phenomena of El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). However, the regional-scale implications of sea surface temperature variability for Africa's carbon sources and sinks have received little focused attention, particularly in the case of IOD. Furthermore, studies exploring the interactive effects of ENSO and IOD when coincident are lacking. This analysis uses remotely sensed vegetation change plus a land surface model driven with observed meteorology to investigate how rainfall, vegetation, and photosynthesis across Africa respond to these climate oscillations. In addition to the relatively well-known ENSO forcing, the IOD induces large departures of photosynthesis across much of Africa associated with anomalies in rainfall and vegetation greenness. More importantly, sizeable independent effects can be suppressed or even reversed by destructive interferences during periods of simultaneous ENSO and IOD activity. For example, effects of positive IOD on southeastern Africa tended to dominate those of El Niño during their coincidence spanning 1997–1998, with sign reversal of El Niño's typically strong suppression of photosynthesis in this region. These findings call into question past analyses examining teleconnections to ENSO or IOD in isolation, and indicate the need to consider their simultaneous states when examining influences on hydroclimatic and ecological conditions across Africa.

scholarly journals The pan-tropical response of soil moisture to El Niño

2019 ◽  
Author(s):  
Kurt C. Solander ◽  
Brent D. Newman ◽  
Alessandro Carioca de Aruajo ◽  
Holly R. Barnard ◽  
Z. Carter Berry ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Southeast Asia ◽  
El Niño ◽  
Amazon Basin ◽  
Multiple Scales ◽  
El Nino ◽  
Climate Anomalies ◽  
Mature Phase ◽  
El Niño Event ◽  
Sst Anomalies

Abstract. The 2015–16 El Niño event ranks as one of the most severe on record in terms of the magnitude and extent of sea surface temperature (SST) anomalies generated in the tropical Pacific Ocean. Corresponding global impacts on the climate were expected to rival, or even surpass, those of the 1997–98 severe El Niño event, which had SST anomalies that were similar in size. However, the 2015–16 event failed to meet expectations for hydrologic change in many areas, including those expected to receive well above normal precipitation. To better understand how climate anomalies during an El Niño event impact soil moisture, we investigate changes in soil moisture in the humid tropics (between ±25°) during the three most recent super El Niño events of 1982–83, 1997–98, and 2015–16, using data from the Global Land Data Assimilation System (GLDAS). First, we validate the soil moisture estimates from GLDAS through comparison with in-situ observations obtained from 16 sites across five continents, showing an r2 of 0.54. Next, we apply a k-means cluster analysis to the soil moisture estimates during the El Niño mature phase, resulting in four groups of clustered data. The strongest and most consistent decreases in soil moisture occur in the Amazon basin and maritime southeast Asia, while the most consistent increases occur over east Africa. In addition, we compare changes in soil moisture to both precipitation and evapotranspiration, which showed a lack of agreement in the direction of change between these variables and soil moisture most prominently in the southern Amazon basin, Sahel and mainland southeast Asia. Our results can be used to improve estimates of spatiotemporal differences in El Niño impacts on soil moisture in tropical hydrology and ecosystem models at multiple scales.

scholarly journals Resistance of African tropical forests to an extreme climate anomaly

2021 ◽  
Vol 118 (21) ◽  
pp. e2003169118
Author(s):  
Amy C. Bennett ◽  
Greta C. Dargie ◽  
Aida Cuni-Sanchez ◽  
John Tshibamba Mukendi ◽  
Wannes Hubau ◽  
...  
Keyword(s):  
Tropical Forests ◽  
El Niño ◽  
Tree Mortality ◽  
El Nino ◽  
Southern Oscillation ◽  
Carbon Sink ◽  
El Niño Event ◽  
Dry Conditions ◽  
Carbon Losses

The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015–2016 El Niño Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015–2016 El Niño event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Niño event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha−1 y−1) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests.

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