scholarly journals Environmental variability during the last three millennia in the rain shadows of central Mexico

2021 ◽  
Vol 73 (1) ◽  
pp. A171220
Author(s):  
Gustavo Olivares-Casillas ◽  
Alex Correa-Metrio ◽  
Edyta Zawisza ◽  
Marta Wojewódka-Przybył ◽  
Maarten Blaauw ◽  
...  
Keyword(s):  
Climate Change ◽  
El Niño ◽  
High Frequency ◽  
Environmental Variability ◽  
El Nino ◽  
Global Climate ◽  
Anthropogenic Activities ◽  
Climatic Variability ◽  
Sea Surface ◽  
Ice Age

The last three millennia have been characterized by global temperature oscillations of around one Celsius degree, and high frequency variability on precipitation. Two main temperature anomalies have been reported worldwide, the Medieval Warm Period (MWP) and the Little Ice Age (LIA), characterized by higher and lower than average temperatures, respectively. Precipitation variability has been mostly associated with El Niño anomalies in the Equatorial Pacific. These global variability modes have been modulated by regional factors such as sea surface temperatures and their interaction with continental landmasses. Understanding regional responses to these anomalies would shed light on ecosystem response to environmental variability, a paramount tool for conservation purposes on the light of modern climate change. Here we present a 3,000-year sedimentary record from Lake Metztitlán, located in a Biosphere Reserve under the rain shadow of the Sierra Madre Oriental. Cladoceran and geochemical analyses were used to reconstruct lacustrine dynamics through the time period encompassed by the record. Our record points to highly dynamic lacustrine systems, coupled with global and regional climatic variability. In Metztitlán, the MWP was associated with low lake levels and a high torrentiality of the precipitation reflected in high-frequency peaks of detrital material. The LIA was associated with an enlarged water body, probably as a result of lower evapotranspiration. Overall, global climatic variability resulted in high variability of regional precipitation and detrital input in the Metztitlán region, in turn associated with changes in lake morphometry and depth. Our record highlights the vulnerability of the area to changes in sea surface temperature of the Gulf of Mexico, and to changes in the frequency of El Niño events. Although the effects of global climate change in the region are inescapable, our results emphasize the importance of controlling anthropogenic activities as an additional source of pressure on the regional ecosystems.

Climate Variability in the Context of Climate Change: El Niño and Other Oscillations

2008 ◽  
Author(s):  
Cynthia Rosenzweig ◽  
Daniel Hillel
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
North Atlantic ◽  
El Niño ◽  
El Nino ◽  
Global Climate ◽  
Climate System ◽  
The Arctic ◽  
The Pacific ◽  
Earth’S Climate

The climate system envelops our planet, with swirling fluxes of mass, momentum, and energy through air, water, and land. Its processes are partly regular and partly chaotic. The regularity of diurnal and seasonal fluctuations in these processes is well understood. Recently, there has been significant progress in understanding some of the mechanisms that induce deviations from that regularity in many parts of the globe. These mechanisms include a set of combined oceanic–atmospheric phenomena with quasi-regular manifestations. The largest of these is centered in the Pacific Ocean and is known as the El Niño–Southern Oscillation. The term “oscillation” refers to a shifting pattern of atmospheric pressure gradients that has distinct manifestations in its alternating phases. In the Arctic and North Atlantic regions, the occurrence of somewhat analogous but less regular interactions known as the Arctic Oscillation and its offshoot, the North Atlantic Oscillation, are also being studied. These and other major oscillations influence climate patterns in many parts of the globe. Examples of other large-scale interactive ocean–atmosphere– land processes are the Pacific Decadal Oscillation, the Madden-Julian Oscillation, the Pacific/North American pattern, the Tropical Atlantic Variability, the West Pacific pattern, the Quasi-Biennial Oscillation, and the Indian Ocean Dipole. In this chapter we review the earth’s climate system in general, define climate variability, and describe the processes related to ENSO and the other major systems and their interactions. We then consider the possible connections of the major climate variability systems to anthropogenic global climate change. The climate system consists of a series of fluxes and transformations of energy (radiation, sensible and latent heat, and momentum), as well as transports and changes in the state of matter (air, water, solid matter, and biota) as conveyed and influenced by the atmosphere, the ocean, and the land masses. Acting like a giant engine, this dynamic system is driven by the infusion, transformation, and redistribution of energy.

scholarly journals Early Pliocene (pre–Ice Age) El Niño–like global climate: Which El Niño?

Geosphere ◽  
2007 ◽  
Vol 3 (5) ◽  
pp. 337 ◽  
Author(s):  
Peter Molnar ◽  
Mark A. Cane
Keyword(s):  
El Niño ◽  
El Nino ◽  
Global Climate ◽  
Ice Age ◽  
Early Pliocene

scholarly journals Spatial correlates of forest and land fires in Indonesia

2020 ◽  
Vol 29 (12) ◽  
pp. 1088
Author(s):  
Z. D. Tan ◽  
L. R. Carrasco ◽  
D. Taylor
Keyword(s):  
El Niño ◽  
Negative Binomial ◽  
El Nino ◽  
Global Climate ◽  
Anthropogenic Activities ◽  
Data Availability ◽  
Management Planning ◽  
Study Region ◽  
Linear Mixed Effects ◽  
Binomial Models

Biomass fires in Indonesia emit high levels of greenhouse gases and particulate matter, key contributors to global climate change and poor air quality in south-east Asia. In order to better understand the drivers of biomass fires across Indonesia over multiple years, we examined the distribution and probability of fires in Sumatra, Kalimantan (Indonesian Borneo) and Papua (western New Guinea) over four entire calendar years (2002, 2005, 2011 and 2015). The 4 years of data represent years with El Niño and La Niña conditions and high levels of data availability in the study region. Generalised linear mixed-effects models and zero-inflated negative binomial models were used to relate fire hotspots and a range of spatial predictor data. Geographic differences in occurrences of fire hotspots were evident. Fire probability was greatest in mixed-production agriculture lands and in deeper, degraded peatlands, suggesting anthropogenic activities were strong determinants of burning. Drought conditions in El Niño years were also significant. The results demonstrate the importance of prioritising areas of high fire probability, based on land use and other predisposing conditions, in effective fire management planning.

scholarly journals Inter-seasonal investigation of coupled C & N greenhouse gas fluxes in pristine northern ecosystems

2021 ◽  
Author(s):  
Lona van Delden ◽  
Julia Boike ◽  
Eeva-Stiina Tuittila ◽  
Timo Vesala ◽  
Claire Treat
Keyword(s):  
Climate Change ◽  
Greenhouse Gas ◽  
High Frequency ◽  
Global Climate ◽  
Climatic Variability ◽  
Direct Interaction ◽  
Growing Season ◽  
Global Scale ◽  
Soil Matrix ◽  
Wetland Ecosystems

<p>Accurate annual greenhouse gas (GHG) budgets are the crucial baseline for global climate change forecast scenarios. On the other hand, the parameterization of these forecast models requires more than high-quality GHG datasets, but also the constant improvement of the representation of GHG producing and consuming processes. Extensive research efforts are therefore focusing on increasing our knowledge of the main GHG producing carbon (C) and nitrogen (N) cycles, though surprisingly not so much into their direct interaction. Most annual GHG budgets from pristine northern ecosystems are based on interpolated datasets from sampling campaigns mainly taken during the growing season. Within the ERC funded FluxWIN project, we are investigating how soil and pore water C & N interact and their biogeochemical GHG drivers change over seasons. Freeze-thaw events have previously been identified as significant GHG drivers by rapidly changing moisture and oxygen conditions in the soil matrix, but it remains unclear if and how C & N coupling contributes to these non-growing season emissions. Therefore, a fully automated static chamber system is monitoring GHG fluxes in high frequency at a boreal peatland ecosystem in Siikaneva, Finland. Nutrient stocks and biogeochemical dynamics within the soil matrix are compared to GHG soil-atmosphere exchange in the form of carbon dioxide (CO<sub>2</sub>), methane (CH<sub>4</sub>) and nitrous oxide (N<sub>2</sub>O) all year-round. We control for climatic variability and isolate differences in non-growing season emissions by using a moisture gradient from well-drained upland soils to adjacent wetland ecosystems. The use of these automated high-frequency GHG measurements in combination with year-round biogeochemical monitoring maximizes the likelihood of capturing episodic emissions and their drivers, which are particularly important during fall freeze and spring thaw periods. The gained information on the coupled C & N biogeochemical cycles will improve feedback estimates of climate change by including non-growing season processes in global-scale process-based models.</p>

Does the El Niño–Southern Oscillation control the interhemispheric radiocarbon offset?

2007 ◽  
Vol 67 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Chris S.M. Turney ◽  
Jonathan G. Palmer
Keyword(s):  
Southern Hemisphere ◽  
El Niño ◽  
Atmospheric Carbon Dioxide ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Ice Age ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Mean Values

AbstractSince the 1970s it has been recognised that Southern Hemisphere samples have a lower radiocarbon content than contemporaneous material in the Northern Hemisphere. This interhemispheric radiocarbon offset has traditionally been considered to be the result of a greater surface area in the southern ocean and high-latitude deepwater formation. This is despite the fact that the El Niño–Southern Oscillation (ENSO) is known to play a significant role in controlling the interannual variability of atmospheric carbon dioxide by changing the flux of ‘old’ CO2 from the tropical Pacific. Here we demonstrate that over the past millennium, the Southern Hemisphere radiocarbon offset is characterised by a pervasive 80-yr cycle with a step shift in mean values coinciding with the transition from the Medieval Warm Period to the Little Ice Age. The observed changes suggest an ENSO-like role in influencing the interhemispheric radiocarbon difference, most probably modulated by the Interdecadal Pacific Oscillation, and supports a tropical role in forcing centennial-scale global climate change.

scholarly journals Study of Climate Change Impact to Local Rainfall Distribution in Lampung Provinces

2016 ◽  
Vol 28 (1) ◽  
Author(s):  
Tumiar Katarina Manik ◽  
Bustomi Rosadi ◽  
Eva Nurhayati
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Global Climate Change ◽  
El Niño ◽  
El Nino ◽  
Global Climate ◽  
Seasonal Pattern ◽  
Rainfall Distribution ◽  
Local Climate ◽  
The Impact

Global warming which leads to climate change has potential affect to Indonesia agriculture activities and production. Analyzing rainfall pattern and distribution is important to investigate the impact of global climate change to local climate. This study using rainfall data from 1976-2010 from both lowland and upland area of Lampung Province. The results show that rainfall tends to decrease since the 1990s which related to the years with El Nino event. Monsoonal pattern- having rain and dry season- still excist in Lampung; however, since most rain fell below the average, it could not meet crops water need. Farmers conclude that dry seasons were longer and seasonal pattern has been changed. Global climate change might affect Lampung rainfall distribution through changes on sea surface temperature which could intensify the El Nino effect. Therefore, watching the El Nino phenomena and how global warming affects it, is important in predicting local climate especially the rainfall distribution in order to prevent significant loss in agriculture productivities.

scholarly journals Was the Little Ice Age more or less El Niño-like than the Mediaeval Climate Anomaly? Evidence from hydrological and temperature proxy data

2015 ◽  
Vol 11 (6) ◽  
pp. 5549-5604
Author(s):  
L. M. K. Henke ◽  
F. H. Lambert ◽  
D. J. Charman
Keyword(s):  
El Niño ◽  
Little Ice Age ◽  
Large Scale ◽  
El Nino ◽  
Global Climate ◽  
Temperature Reconstruction ◽  
Ice Age ◽  
Climate Anomaly ◽  
Proxy Data ◽  
Proxy Records

Abstract. The El Niño-Southern Oscillation (ENSO), an ocean–atmosphere coupled oscillation over the equatorial Pacific, is the most important source of global climate variability on inter-annual time scales. It has substantial environmental and socio-economic consequences such as devastation of South American fish populations and increased forest fires in Indonesia. The instrumental ENSO record is too short for analysing long-term trends and variability, hence proxy data is used to extend the record. However, different proxy sources have produced varying reconstructions of ENSO, with some evidence for a temperature–precipitation divergence in ENSO trends over the past millennium, in particular during the Mediaeval Climate Anomaly (MCA; AD 800–1300) and the Little Ice Age (LIA; AD 1400–1850). This throws into question the stability of the modern ENSO system and its links to the global climate, which has implications for future projections. Here we use a new statistical approach using EOF-based weighting to create two new large-scale ENSO reconstructions derived independently from precipitation proxies and temperature proxies respectively. The method is developed and validated using pseudoproxy experiments that address the effects of proxy dating error, resolution and noise to improve uncertainty estimations. The precipitation ENSO reconstruction displays a significantly more El Niño-like state during the LIA than the MCA, while the temperature reconstruction shows no significant difference. The trends shown in the precipitation ENSO reconstruction are relatively robust to variations in the precipitation EOF pattern. However, the temperature reconstruction suffers significantly from a lack of high-quality, favourably located proxy records, which limits its ability to capture the large-scale ENSO signal. Further expansion of the palaeo-database and improvements to instrumental, satellite and model representations of ENSO are needed to fully resolve the discrepancies found among proxy records.

scholarly journals A Response Characteristics Study of Widespread Power Grid Icing to El Nino

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Yuelun Di ◽  
Jiazheng Lu ◽  
Xunjian Xu ◽  
Tao Feng ◽  
Li Li
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
El Niño ◽  
El Nino ◽  
Global Climate ◽  
Power Grid ◽  
Ice Thickness ◽  
Winter Climate ◽  
Response Characteristics ◽  
Surrounding Areas

Under the circumstances of global climate change, the El Nino event affects power grid icing by influencing the winter climate characteristics. The response characteristics of the massive power grid icing to El Nino should be of concern. Based on analysis and comparison, this study found that the overall level of response of Hunan power grid icing to El Nino was weak in 2015 winter. Areas with severe power grid icing of Hunan at 2015 El Nino period are mainly distributed at the midwest and southeastern mountainous and surrounding areas, but the maximum ice thickness extremum area range is shrinking. The maximum ice thickness at the El Nino winter enhancing (weakening) follows the trend of El Nino increasing (decreasing). Overall, the maximum ice thickness response characteristics of Hunan power grid at the El Nino period can be divided into four types. This analysis of power grid icing characteristics during El Nino period summarizes the response characteristics of icing and can guide the research of power grid icing and ant-icing countermeasures.

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