scholarly journals Impact of developing ENSO on the Tibetan Plateau summer rainfall

2021 ◽  
pp. 1-56
Author(s):  
Shuai Hu ◽  
Tianjun Zhou ◽  
Bo Wu
Keyword(s):  
Tibetan Plateau ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Summer Rainfall ◽  
Climate Impacts ◽  
South Asian High ◽  
The Tibetan Plateau ◽  
Research Attention

AbstractThe year-to-year variations of Tibetan Plateau (TP) summer rainfall have tremendous climate impacts on the adjoining and even global climate, attracting extensive research attention in recent decades to understand the underlying mechanism. In this study, we investigate an open question of how the El Niño-Southern Oscillation (ENSO) influences the TP precipitation. We show that the developing ENSO has significant impacts on the summer rainfall over the southwestern TP (SWTP), which is the second EOF mode of the interannual variability of summer rainfall over the TP. Moisture budget indicates that both the suppressed vertical motion and the deficit of moisture contribute to the reduction of SWTP rainfall during El Niño’s developing summer, with the former contribution four times larger than the latter. Moist static energy analyses indicate that the anomalous advection of climatological moist enthalpy by anomalous zonal wind is responsible for the anomalous descending motions over the SWTP. The El Niño-related southward displacements of the South Asian high and the upper-level cyclonic anomalies over the west of TP stimulated by the suppressed Indian summer monsoon precipitation are two key processes dominating the anomalous zonal moist enthalpy advection over SWTP. Meanwhile, the India-Burma monsoon trough is strengthened during El Niño developing summer, which prevents the water vapor into the SWTP, and thus contributes to the deficit of summer SWTP rainfall. Our results help to understand the complicated ENSO-related air-sea interaction responsible for the variability of TP precipitation and have implications for seasonal prediction of the TP climate.

Integration of Tibetan Plateau ice-core temperature records and the influence of atmospheric circulation on isotopic signals in the past century

2014 ◽  
Vol 81 (3) ◽  
pp. 520-530 ◽  
Author(s):  
Xiaoxin Yang ◽  
Tandong Yao ◽  
Daniel Joswiak ◽  
Ping Yao
Keyword(s):  
Tibetan Plateau ◽  
Atmospheric Circulation ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Ice Core ◽  
Past Century ◽  
The Tibetan Plateau ◽  
The Past ◽  
Increasing Trends

AbstractTemperature signals in ice-core δ18O on the Tibetan Plateau (TP), particularly in the central and southern parts, continue to be debated because of the large scale of atmospheric circulation. This study presents ten ice-core δ18O records at an annual resolution, with four (Malan, Muztagata, Guliya, and Dunde) in the northern, three (Puruogangri, Geladaindong, Tanggula) in the central and three (Noijin Kangsang, Dasuopu, East Rongbuk) in the southern TP. Integration shows commonly increasing trends in δ18O in the past century, featuring the largest one in the northern, a moderate one in the central and the smallest one in the southern TP, which are all consistent with ground-based measurements of temperature. The influence of atmospheric circulation on isotopic signals in the past century was discussed through the analysis of El Niño/Southern Oscillation (ENSO), and of possible connections between sea surface temperature (SST) and the different increasing trends in both ice-core δ18O and temperature. Particularly, El Niño and the corresponding warm Bay of Bengal (BOB) SST enhance the TP ice-core isotopic enrichment, while La Niña, or corresponding cold BOB SST, causes depletion. This thus suggests a potential for reconstructing the ENSO history from the TP ice-core δ18O.

scholarly journals Reconciling the Discrepancy of Post-Volcanic Cooling Estimated from Tree-Ring Reconstructions and Model Simulations over the Tibetan Plateau

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 738
Author(s):  
Jianping Duan ◽  
Peili Wu ◽  
Zhuguo Ma
Keyword(s):  
Tibetan Plateau ◽  
Climate Variability ◽  
Tree Ring ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Volcanic Eruptions ◽  
The Tibetan Plateau ◽  
Model Simulations ◽  
Internal Climate Variability

Volcanic eruptions are a major factor influencing global climate variability, usually with a cooling effect. The magnitudes of post-volcanic cooling from historical eruptions estimated by tree-ring reconstructions differ considerably with the current climate model simulations. It remains controversial on what is behind such a discrepancy. This study investigates the role of internal climate variability (i.e., El Niño/Southern Oscillation (ENSO) warm phase) with a regional focus on the Tibetan Plateau (TP), using tree-ring density records and long historical climate simulations from the fifth Coupled Model Intercomparsion Project (CMIP5). We found that El Niño plays an important role behind the inconsistencies between model simulations and reconstructions. Without associated El Niño events, model simulations agree well with tree-ring records. Divergence appears when large tropical eruptions are followed by an El Niño event. Model simulations, on average, tend to overestimate post-volcanic cooling during those periods as the occurrence of El Niño is random as part of internal climate variability.

scholarly journals Remote Effects of IOD and ENSO on Motivating the Atmospheric Pattern Favorable for Snowfall Over the Tibetan Plateau in Early Winter

2021 ◽  
Vol 3 ◽  
Author(s):  
Hongyan Shen ◽  
Zhiqiang Gong ◽  
Boqi Liu ◽  
Yipeng Guo ◽  
Xiaoli Feng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Thermal Conditions ◽  
The Tibetan Plateau ◽  
Early Winter ◽  
Atmospheric Conditions ◽  
Leading Role ◽  
Community Atmosphere Model

The interannual variation of snowfall over the Tibetan Plateau (TP) in early winter (November–December) and its related atmospheric attribution are clarified. Meanwhile, the influence of tropical sea surface temperatures (SSTs) on TP snowfall is investigated by diagnostic analyses and Community Atmosphere Model (CAM5) simulations. The leading mode of TP snowfall in early winter features a spatially uniform pattern with remarkable interannual variability. It is found that the Indian Ocean Dipole (IOD) and El Niño Southern Oscillation (ENSO) are main external forcing factors for TP snowfall. Positive IOD with positive ENSO and positive IOD with neutral ENSO cases both have remote impact on motivating Southern Eurasia (SEA) pattern, which can induce an anomalous cyclone around the TP. The corresponding anomalous ascending motion and cold air in the mid-upper troposphere provide the dynamical and thermal conditions for heavy snowfall. The low-level southwesterly winds are enhanced over the Arabian Sea and Bay of Bengal, bringing abundant water vapor into the TP for excessive snowfall. Furthermore, CAM5 simulation experiments forced by IOD- and ENSO-related SST anomalies are performed to verify their combined and independent effects on TP snowfall in early winter. It is confirmed that either positive IOD or El Niño has certain impacts on motivating circulation anomalies favorable for snowfall over the TP. However, IOD plays a leading role in producing the excessive snowfall-related atmospheric conditions, and there is an asymmetric influence of ENSO and IOD on the TP snowfall.

ENSO modulates the variability of ice core δ18O in the central Tibetan Plateau

2020 ◽  
Author(s):  
Jing Gao ◽  
Tandong Yao ◽  
Guangjian Wu ◽  
Camille Risi
Keyword(s):  
Tibetan Plateau ◽  
El Niño ◽  
Land Surface ◽  
El Nino ◽  
Southern Oscillation ◽  
Ice Core ◽  
The Tibetan Plateau ◽  
Ice Core Record ◽  
Tropical Sea ◽  
Annual Scale

<p>The El Nino-Southern Oscillation (ENSO) drives interannual variability of rainfall, ecosystems and floods in many parts of the world. Climates in the Tibetan Plateau (TP) called as the “water tower” may be impacted by ENSO, but the character of ENSO impact and its mechanism are still not well understood. Here we present the isotopic profiles (δ<sup>18</sup>O) from a new Zangsegangri (ZSGR) ice core drilled in 2013 in the central TP covering 200 years to understand the ENSO impact on the TP climate. The imprint of ENSO is evidenced at annual scale as recorded in ice core. This ice core δ<sup>18</sup>O record also reveal contributions of south/north moisture sources change with the transition of El nino/La nina events which are triggered by the tropical sea surface temperature, associated with the change of convections along the moisture transport paths. These rapid changes lead to the variation of ZSGR ice core δ<sup>18</sup>O, namely El Nino events result in lower δ<sup>18</sup>O in the ZSGR ice core record. The mechanism of ENSO impact on the ZSGR ice core δ<sup>18</sup>O are quantified with LMDZiso model. The significant impact of ENSO activity on the Tibetan ice core record during the past centuries implies the importance of ENSO in land surface processes in the TP.</p>

scholarly journals El Niño–Southern Oscillation and its impact in the changing climate

2018 ◽  
Vol 5 (6) ◽  
pp. 840-857 ◽  
Author(s):  
Song Yang ◽  
Zhenning Li ◽  
Jin-Yi Yu ◽  
Xiaoming Hu ◽  
Wenjie Dong ◽  
...  
Keyword(s):  
El Niño ◽  
Climate Models ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Climate Impacts ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Conventional View ◽  
Future Global Warming

AbstractExtensive research has improved our understanding and forecast of the occurrence, evolution and global impacts of the El Niño–Southern Oscillation (ENSO). However, ENSO changes as the global climate warms up and it exhibits different characteristics and climate impacts in the twenty-first century from the twentieth century. Climate models project that ENSO will also change in the warming future and have not reached an agreement about the flavor, as to the intensity and the frequency, of future ENSO conditions. This article presents the conventional view of ENSO properties, dynamics and teleconnections, and reviews the emerging understanding of the diversity and associated climate impacts of ENSO. It also reviews the results from investigations into the possible changes in ENSO under the future global-warming scenarios.

scholarly journals Spurious North Tropical Atlantic precursors to El Niño

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjun Zhang ◽  
Feng Jiang ◽  
Malte F. Stuecker ◽  
Fei-Fei Jin ◽  
Axel Timmermann
Keyword(s):  
El Niño ◽  
Cross Correlation ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Tropical Atlantic ◽  
The North ◽  
Sst Variability ◽  
Primary Driver ◽  
North Tropical Atlantic

AbstractThe El Niño-Southern Oscillation (ENSO), the primary driver of year-to-year global climate variability, is known to influence the North Tropical Atlantic (NTA) sea surface temperature (SST), especially during boreal spring season. Focusing on statistical lead-lag relationships, previous studies have proposed that interannual NTA SST variability can also feed back on ENSO in a predictable manner. However, these studies did not properly account for ENSO’s autocorrelation and the fact that the SST in the Atlantic and Pacific, as well as their interaction are seasonally modulated. This can lead to misinterpretations of causality and the spurious identification of Atlantic precursors for ENSO. Revisiting this issue under consideration of seasonality, time-varying ENSO frequency, and greenhouse warming, we demonstrate that the cross-correlation characteristics between NTA SST and ENSO, are consistent with a one-way Pacific to Atlantic forcing, even though the interpretation of lead-lag relationships may suggest otherwise.

Summer Cooling Driven by Large Volcanic Eruptions over the Tibetan Plateau

2018 ◽  
Vol 31 (24) ◽  
pp. 9869-9879 ◽  
Author(s):  
Jianping Duan ◽  
Lun Li ◽  
Zhuguo Ma ◽  
Jan Esper ◽  
Ulf Büntgen ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
El Niño ◽  
El Nino ◽  
Volcanic Eruptions ◽  
The Tibetan Plateau ◽  
Temperature Deviation ◽  
El Niño Event ◽  
El Niño Events ◽  
Large Volcanic Eruptions ◽  
El Nino Events

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.

scholarly journals The El Niño: A Meteorological Risk Factor for Vector-borne Diseases

2021 ◽  
Author(s):  
Avi Patel ◽  
Keyword(s):  
El Niño ◽  
Neglected Tropical Diseases ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Economic Loss ◽  
Tropical Diseases ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
Climate Crisis

The El Niño Southern Oscillation (ENSO) has been ravaging numerous coastal and inland communities with excessive flooding and drought conditions, causing immense economic loss, and the incidence of many neglected tropical diseases. Affecting over 60 million people directly, El Niño remains one of the greatest enigmas to human health, and combined with the ever-escalating global climate crisis, El Niño events are only projected to increase in magnitude in the coming years (WHO, 2016).

scholarly journals The Impact of Obliquity Change on El Niño Southern Oscillation (ENSO) and La Niña Climate Episodes

2022 ◽  
Author(s):  
Paul C. Rivera
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Global Climate ◽  
Global Climate Model ◽  
La Niña ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
La Nina ◽  
The Impact

An alternative physical mechanism is proposed to describe the occurrence of the episodic El Nino Southern Oscillation (ENSO) and La Nina climatic phenomena. This is based on the earthquake-perturbed obliquity change (EPOCH) model previously discovered as a major cause of the global climate change problem. Massive quakes impart a very strong oceanic force that can move the moon which in turn pulls the earth’s axis and change the planetary obliquity. Analysis of the annual geomagnetic north-pole shift and global seismic data revealed this previously undiscovered force. Using a higher obliquity in the global climate model EdGCM and constant greenhouse gas forcing showed that the seismic-induced polar motion and associated enhanced obliquity could be the major mechanism governing the mysterious climate anomalies attributed to El Nino and La Nina cycles.

scholarly journals The impact of the 2015/2016 El Niño on global photosynthesis using satellite remote sensing

2018 ◽  
Vol 373 (1760) ◽  
pp. 20170409 ◽  
Author(s):  
Xiangzhong Luo ◽  
Trevor F. Keenan ◽  
Joshua B. Fisher ◽  
Juan-Carlos Jiménez-Muñoz ◽  
Jing M. Chen ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Carbon Cycle ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Carbon Sink ◽  
Global Climate ◽  
Prognostic Models ◽  
Positive Anomaly ◽  
The Impact

The El Niño-Southern Oscillation exerts a large influence on global climate regimes and on the global carbon cycle. Although El Niño is known to be associated with a reduction of the global total land carbon sink, results based on prognostic models or measurements disagree over the relative contribution of photosynthesis to the reduced sink. Here, we provide an independent remote sensing-based analysis on the impact of the 2015–2016 El Niño on global photosynthesis using six global satellite-based photosynthesis products and a global solar-induced fluorescence (SIF) dataset. An ensemble of satellite-based photosynthesis products showed a negative anomaly of −0.7 ± 1.2 PgC in 2015, but a slight positive anomaly of 0.05 ± 0.89 PgC in 2016, which when combined with observations of the growth rate of atmospheric carbon dioxide concentrations suggests that the reduction of the land residual sink was likely dominated by photosynthesis in 2015 but by respiration in 2016. The six satellite-based products unanimously identified a major photosynthesis reduction of −1.1 ± 0.52 PgC from savannahs in 2015 and 2016, followed by a highly uncertain reduction of −0.22 ± 0.98 PgC from rainforests. Vegetation in the Northern Hemisphere enhanced photosynthesis before and after the peak El Niño, especially in grasslands (0.33 ± 0.13 PgC). The patterns of satellite-based photosynthesis ensemble mean were corroborated by SIF, except in rainforests and South America, where the anomalies of satellite-based photosynthesis products also diverged the most. We found the inter-model variation of photosynthesis estimates was strongly related to the discrepancy between moisture forcings for models. These results highlight the importance of considering multiple photosynthesis proxies when assessing responses to climatic anomalies. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.

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