Asian Summer Precipitation over the Past 544 Years Reconstructed by Merging Tree Rings and Historical Documentary Records

2018 ◽  
Vol 31 (19) ◽  
pp. 7845-7861 ◽  
Author(s):  
Hui Shi ◽  
Bin Wang ◽  
Edward R. Cook ◽  
Jian Liu ◽  
Fei Liu
Keyword(s):  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Rainfall Variability ◽  
Low Frequency ◽  
Summer Precipitation ◽  
Small Scale ◽  
Central Pacific El Niño ◽  
Asian Summer ◽  
Mode A

Sparse long-term Asian monsoon (AM) records have limited our ability to understand and accurately model low-frequency AM variability. Here we present a gridded 544-yr (from 1470 to 2013) reconstructed Asian summer precipitation (RAP) dataset by weighted merging of two complementary proxies including 453 tree-ring-width chronologies and 71 historical documentary records. The RAP dataset provides substantially improved data quality when compared with single-proxy-type reconstructions. Skillful reconstructions are obtained in East and North China, northern India and Pakistan, the Indochina Peninsula, midlatitude Asia, the Maritime Continent, and southern Japan. The RAP faithfully illustrates large-scale regional rainfall variability but has more uncertainties in representing small-scale local rainfall anomalies. The RAP reproduces a realistic climatology and captures well the year-to-year rainfall variability averaged over monsoon Asia, arid central Asia, and all of Asia during the twentieth century. It also shows a general agreement with other proxies (speleothems and ice cores) during the period of 1470–1920. The RAP captures the remarkably abrupt change during the 1600s recorded in the upwelling proxy over the Arabian Sea. Four major modes of variability of the Asian summer precipitation are identified with the long record of the RAP, including a biennial El Niño–Southern Oscillation (ENSO) mode, a low-frequency ENSO mode, a central Pacific El Niño–like decadal mode, and an interdecadal mode. In sum, the RAP provides a valuable dataset for study of the large-scale Asian summer precipitation variability, especially the decadal–centennial variability that is caused by external forcing and internal feedback processes within the Earth climate system.

Large‐scale reductions in terrestrial carbon uptake following central Pacific El Niño

2021 ◽  
Author(s):  
Matthew P. Dannenberg ◽  
William K. Smith ◽  
Yulong Zhang ◽  
Conghe Song ◽  
Deborah N. Huntzinger ◽  
...  
Keyword(s):  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Carbon Uptake ◽  
Terrestrial Carbon ◽  
Central Pacific ◽  
Central Pacific El Niño

scholarly journals Orographically Anchored El Niño Effect on Summer Rainfall in Central China

2017 ◽  
Vol 30 (24) ◽  
pp. 10037-10045 ◽  
Author(s):  
Kaiming Hu ◽  
Shang-Ping Xie ◽  
Gang Huang
Keyword(s):  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Rainfall Variability ◽  
Eastern China ◽  
Summer Rainfall ◽  
Central China ◽  
Northwest Pacific ◽  
The Tibetan Plateau ◽  
Rainfall Anomalies

Year-to-year variations in summer precipitation have great socioeconomic impacts on China. Historical rainfall variability over China is investigated using a newly released high-resolution dataset. The results reveal summer-mean rainfall anomalies associated with ENSO that are anchored by mountains in central China east of the Tibetan Plateau. These orographically anchored hot spots of ENSO influence are poorly represented in coarse-resolution datasets so far in use. In post–El Niño summers, an anomalous anticyclone forms over the tropical northwest Pacific, and the anomalous southwesterlies on the northwest flank cause rainfall to increase in mountainous central China through orographic lift. At upper levels, the winds induce additional adiabatic updraft by increasing the eastward advection of warm air from Tibet. In post–El Niño summers, large-scale moisture convergence induces rainfall anomalies elsewhere over flat eastern China, which move northward from June to August and amount to little in the seasonal mean.

scholarly journals Tropospheric column ozone response to ENSO in GEOS-5 assimilation of OMI and MLS ozone data

2016 ◽  
Vol 16 (11) ◽  
pp. 7091-7103 ◽  
Author(s):  
Mark A. Olsen ◽  
Krzysztof Wargan ◽  
Steven Pawson
Keyword(s):  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Southern Oscillation ◽  
Convective Transport ◽  
Vertical Transport ◽  
Small Scale ◽  
Middle Latitudes ◽  
Column Ozone ◽  
The Tropics

Abstract. We use GEOS-5 analyses of Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone observations to investigate the magnitude and spatial distribution of the El Niño Southern Oscillation (ENSO) influence on tropospheric column ozone (TCO) into the middle latitudes. This study provides the first explicit spatially resolved characterization of the ENSO influence and demonstrates coherent patterns and teleconnections impacting the TCO in the extratropics. The response is evaluated and characterized by both the variance explained and sensitivity of TCO to the Niño 3.4 index. The tropospheric response in the tropics agrees well with previous studies and verifies the analyses. A two-lobed response symmetric about the Equator in the western Pacific/Indonesian region seen in some prior studies and not in others is confirmed here. This two-lobed response is consistent with the large-scale vertical transport. We also find that the large-scale transport in the tropics dominates the response compared to the small-scale convective transport. The ozone response is weaker in the middle latitudes, but a significant explained variance of the TCO is found over several small regions, including the central United States. However, the sensitivity of TCO to the Niño 3.4 index is statistically significant over a large area of the middle latitudes. The sensitivity maxima and minima coincide with anomalous anti-cyclonic and cyclonic circulations where the associated vertical transport is consistent with the sign of the sensitivity. Also, ENSO related changes to the mean tropopause height can contribute significantly to the midlatitude response. Comparisons to a 22-year chemical transport model simulation demonstrate that these results from the 9-year assimilation are representative of the longer term. This investigation brings insight to several seemingly disparate prior studies of the El Niño influence on tropospheric ozone in the middle latitudes.

scholarly journals Evolution of the 2006–2007 El Niño: the role of intraseasonal to interannual time scale dynamics

2008 ◽  
Vol 14 ◽  
pp. 219-230 ◽  
Author(s):  
M. J. McPhaden
Keyword(s):  
El Niño ◽  
Time Scale ◽  
Large Scale ◽  
El Nino ◽  
Low Frequency ◽  
Enso Cycle ◽  
Interannual Time Scale ◽  
Unusual Behavior ◽  
Factors Affecting

Abstract. We describe development of the 2006–2007 El Niño, which started late, ended early and was below average strength. Emphasis is on the interplay between large scale, low frequency (i.e., seasonal-to-interannual time scale) deterministic dynamics and episodic intraseasonal wind forcing in the evolution of the event. Efforts to forecast the El Niño are reviewed, with discussion of factors affecting its predictability. Perspectives on the contemporaneous development of an Indian Ocean Dipole Zonal Mode event in 2006 and possible influences of global warming on the ENSO cycle, which exhibited unusual behavior in the first decade of the 21st century, will also be presented.

scholarly journals Tropospheric column ozone response to ENSO in GEOS-5 assimilation of OMI and MLS ozone data

2016 ◽  
Author(s):  
M. A. Olsen ◽  
K. Wargan ◽  
S. Pawson
Keyword(s):  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Southern Oscillation ◽  
Convective Transport ◽  
Vertical Transport ◽  
Small Scale ◽  
Middle Latitudes ◽  
Column Ozone ◽  
The Tropics

Abstract. We use GEOS-5 analyses of Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone observations to investigate the magnitude and spatial distribution of the El Niño Southern Oscillation (ENSO) influence on tropospheric column ozone (TCO) into the middle latitudes. This study provides the first explicit spatially resolved characterization of the ENSO influence and demonstrates coherent patterns and teleconnections impacting the TCO in the extratropics. The response is evaluated and characterized by both the variance explained and sensitivity of TCO to the Niño 3.4 index. The tropospheric response in the tropics agrees well with previous studies and verifies the analyses. However, we show a newly identified two-lobed response symmetric about the Equator in the western Pacific/Indonesian region consistent with the large-scale vertical transport. We also find that the large-scale transport in the tropics dominates the response compared to the small-scale convective transport. The ozone response is weaker in the middle latitudes, but significant explained variance of the TCO is found over several small regions, including the central United States. However, the sensitivity of TCO to the Niño 3.4 index is statistically significant over a large area of the middle latitudes. The sensitivity maxima and minima coincide with anomalous anti-cyclonic and cyclonic circulations where the associated vertical transport is consistent with the sign of the sensitivity. Also, ENSO related changes to the mean tropopause height can contribute significantly to the midlatitude response. Comparisons to a 22-year chemical transport model simulation demonstrate that these results from the nine-year assimilation are representative of the longer-term. This investigation brings insight to several seemingly disparate prior studies of the El Niño influence on tropospheric ozone in the middle latitudes.

scholarly journals The 10–20 d Low-Frequency Oscillation Characteristics of Summer Precipitation in Eastern China in the Decaying Year of CP ENSO

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 616
Author(s):  
Cong Cai ◽  
Lijuan Wang ◽  
Junyu Wang ◽  
Zhiqiang Wang
Keyword(s):  
El Niño ◽  
El Nino ◽  
Eastern China ◽  
Low Frequency ◽  
Summer Precipitation ◽  
La Niña ◽  
Low Frequency Oscillation ◽  
Cp El Niño ◽  
La Nina ◽  
Oscillation Characteristics

Using National Centers for Atmospheric Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data and observational data, the low-frequency oscillation characteristics of precipitation in eastern China during the decaying summer of central Pacific El Niño–Southern Oscillation (CP ENSO) and the corresponding low-frequency atmospheric oscillation characteristic were investigated. The results showed that summer precipitation in eastern China during the decaying year of CP El Niño (La Niña) was more (less) than the climatological mean and that 10–20 d was its dominant period. Low-frequency oscillations at different tropospheric levels had different effects on low-frequency precipitation. In the upper troposphere, Eastern China was dominated by low-frequency divergence and positive (negative) anomaly of low-frequency height during the decaying year of CP El Niño (La Niña), and there was strong (weak) northwest–southeast wave-active flux transport. In the middle troposphere, the range and intensity of the subtropical western Pacific High (SWPH) of CP El Niño was larger and stronger than that of CP La Niña, which may be related to the low-frequency height fields. Meanwhile, the correspnding low-frequency wind field, water vapor circulation systems and moisture transport channels in the lower troposphere, along with the low-frequency vertical movement were significantly different, causing the low-frequency precipitation of CP El Niño to be stronger than CP La Niña.

scholarly journals ENSO diversity driving low-frequency change in mesoscale activity off Peru and Chile

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Carlos Conejero ◽  
Boris Dewitte ◽  
Véronique Garçon ◽  
Joël Sudre ◽  
Ivonne Montes
Keyword(s):  
El Niño ◽  
El Nino ◽  
Low Frequency ◽  
Altimeter Data ◽  
Central Pacific El Niño ◽  
Central Chile ◽  
El Niño Event ◽  
El Niño Events ◽  
Ep El Niño ◽  
El Nino Events

Abstract Transient mesoscale oceanic eddies in Eastern Boundary Upwelling Systems are thought to strongly affect key regional scale processes such as ocean heat transport, coastal upwelling and productivity. Understanding how these can be modulated at low-frequency is thus critical to infer their role in the climate system. Here we use 26 years of satellite altimeter data and regional oceanic modeling to investigate the modulation of eddy kinetic energy (EKE) off Peru and Chile by ENSO, the main mode of natural variability in the tropical Pacific. We show that EKE tends to increase during strong Eastern Pacific (EP) El Niño events along the Peruvian coast up to northern Chile and decreases off central Chile, while it is hardly changed during Central Pacific El Niño and La Niña events. However the magnitude of the EKE changes during strong EP El Niño events is not proportional to their strength, with in particular the 1972/1973 El Niño event standing out as an extreme event in terms of EKE increase off Peru reaching an amplitude three times as large as that during the 1997/1998 El Niño event, and the 2015/2016 El Niño having instead a weak impact on EKE. This produces decadal changes in EKE, with a similar pattern than that of strong EP El Niño events, resulting in a significant negative (positive) long-term trend off Peru (central Chile).

scholarly journals Differential Influences of Teleconnections from the Indian and Pacific Oceans on Rainfall Variability in Southeast Asia

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 886
Author(s):  
Abdul Azim Amirudin ◽  
Ester Salimun ◽  
Fredolin Tangang ◽  
Liew Juneng ◽  
Muhamad Zuhairi
Keyword(s):  
Indian Ocean ◽  
Southeast Asia ◽  
El Niño ◽  
El Nino ◽  
Rainfall Variability ◽  
June July August ◽  
Rainfall Patterns ◽  
Negative Impacts ◽  
The Individual ◽  
June July

This study investigates the individual and combined impacts of El Niño and the positive Indian Ocean Dipole (IOD) on the Southeast Asia (SEA) rainfall variability. Using composite and partial correlation techniques, it is shown that both inter-annual events have individually distinct impacts on the SEA rainfall anomaly distribution. The results showed that the impacts of the co-occurrence of El Niño and IOD events are significant compared to the individual effects of pure El Niño or pure IOD. During June-July-August and September-October-November, the individual impacts of the pure El Niño and IOD events are similar but less significant. Both events caused negative impacts over the southern part of SEA during June-July-August (JJA) and propagated northeastward/eastward during September-October-November (SON). Thus, there are significant negative impacts over the southern part of SEA during the co-occurrence of both events. The differential impacts on the anomalous rainfall patterns are due to the changes in the sea surface temperature (SST) surrounding the region. Additionally, the differences are also related to the anomalous regional atmospheric circulations that interact with the regional SST. The anomalous Walker circulation that connects the Indian Ocean and tropical Pacific Ocean also plays a significant role in determining the regional anomalous rainfall patterns.

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