scholarly journals Role of synoptic eddy feedback on polar climate responses to the anthropogenic forcing

2010 ◽  
Vol 37 (14) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jong-Seong Kug ◽  
Da-Hee Choi ◽  
Fei-Fei Jin ◽  
Won-Tae Kwon ◽  
Hong-Li Ren
2020 ◽  
Author(s):  
Vittal Hari ◽  
Oldrich Rakovec ◽  
Martin Hanel ◽  
Yannis Markonis ◽  
Rohini Kumar

<p>The damages caused by climate extremes to socio-economy and environment is unprecedented during the recent decades, and it causes even more damage when the climate extremes occur in consecutive years. Since the starting of this Century, Europe has witnessed a series of extreme droughts (2003, 2010, 2015, 2018-19) with substantial socioeconomic and ecological losses. This study, with the help of long term data inventory starting from 1766-present, evaluates the occurrence of consecutive two-year droughts using Standardized Precipitation Index (SPI) and Standard Precipitation-Evaporation Index (SPEI) during the vegetation period. Although, the 2018 drought is reported in many of the recent studies, 2019 also suffered a huge rainfall deficit together with rising atmospheric temperature. This indicates an increasing evapotranspiration rates, which may intensify the existing drought conditions that originally developed from rainfall deficits. These effects are further noticed in terms of widespread reduction in the overall vegetative development during 2018-2019.</p><p>Considering this impact, we evaluate 2018-19 droughts in terms of both SPI and SPEI and compare its extent with the extreme hot drought of 2003 to place these ongoing droughts within a climatological context. The average severity of the combined two-year drought event (2018-19) is comparable to that of the 2003 drought. However, for the 2003 event, the drought recovered during the proceeding year, which was not the case for the year 2018-19, which is evident from decline in vegetation development dynamics. Furthermore, the analysis with consecutive droughts during 2018-19 in Central Europe shows that it is a very rare event with a return period of over 200 years; and therefore can be considered as one of the most severe droughts in Europe since 1766. </p><p>Using a suite of climate model simulations from CMIP-5 (N=12), we detected an important and potential role of human-induced climate change in increasing the risk of occurrence of the consecutive droughts over central Europe. Here, with the implementation of the fraction of attributable risk (FAR), we show the signifying role of human influence (or anthropogenic forcing) in modulating the consecutive year droughts. Furthermore, these events in the future projection of climate models suggest an increasing frequency in the latter part of 21st century.</p>


2017 ◽  
Vol 29 (7) ◽  
pp. 2045-2059 ◽  
Author(s):  
José Antonio López-Sáez ◽  
Grettel Vargas ◽  
Jesús Ruiz-Fernández ◽  
Olivier Blarquez ◽  
Francisca Alba-Sánchez ◽  
...  

2014 ◽  
Vol 02 (02) ◽  
pp. 1450015
Author(s):  
Xingshu ZHAO

The United States and China have common but differentiated climate mitigation responses. Most studies so far have sought to explain this divergence with a focus on energy resources, technology, economic, or social factors. These studies ignore the role of strategy and institutions, and thus appear incomplete. In this paper, the author investigates the climate mitigation responses of the United States and China from a strategic and institutional perspective, explores how their climate responses are shaped, and identifies possible weaknesses hidden in their climate approaches. The paper finds that the United States and China have distinct national climate positions due to their diverse strategies and institutions. However, they have chosen similar policy tools and have achieved fairly comparable emission reductions thus far. In the long run, the effectiveness and efficiency of the low-carbon transformation will possibly be hindered by weaker policy innovation capability at sub-national levels in China and the operationally volatile energy strategy in the United States.


2010 ◽  
Vol 115 (D17) ◽  
Author(s):  
Da-Hee Choi ◽  
Jong-Seong Kug ◽  
Won-Tae Kwon ◽  
Fei-Fei Jin ◽  
Hee-Jeong Baek ◽  
...  

2018 ◽  
Vol 31 (22) ◽  
pp. 9313-9333 ◽  
Author(s):  
John P. Krasting ◽  
Ronald J. Stouffer ◽  
Stephen M. Griffies ◽  
Robert W. Hallberg ◽  
Sergey L. Malyshev ◽  
...  

Abstract Oceanic heat uptake (OHU) is a significant source of uncertainty in both the transient and equilibrium responses to increasing the planetary radiative forcing. OHU differs among climate models and is related in part to their representation of vertical and lateral mixing. This study examines the role of ocean model formulation—specifically the choice of the vertical coordinate and the strength of the background diapycnal diffusivity Kd—in the millennial-scale near-equilibrium climate response to a quadrupling of atmospheric CO2. Using two fully coupled Earth system models (ESMs) with nearly identical atmosphere, land, sea ice, and biogeochemical components, it is possible to independently configure their ocean model components with different formulations and produce similar near-equilibrium climate responses. The SST responses are similar between the two models (r2 = 0.75, global average ~4.3°C) despite their initial preindustrial climate mean states differing by 0.4°C globally. The surface and interior responses of temperature and salinity are also similar between the two models. However, the Atlantic meridional overturning circulation (AMOC) responses are different between the two models, and the associated differences in ventilation and deep-water formation have an impact on the accumulation of dissolved inorganic carbon in the ocean interior. A parameter sensitivity analysis demonstrates that increasing the amount of Kd produces very different near-equilibrium climate responses within a given model. These results suggest that the impact of the ocean vertical coordinate on the climate response is small relative to the representation of subgrid-scale mixing.


2014 ◽  
Vol 140 ◽  
pp. 134-145 ◽  
Author(s):  
S. Pakhomova ◽  
E. Vinogradova ◽  
E. Yakushev ◽  
A. Zatsepin ◽  
G. Shtereva ◽  
...  

2015 ◽  
Vol 96 (12) ◽  
pp. S111-S114
Author(s):  
Lianchun Song ◽  
Siyan Dong ◽  
Ying Sun ◽  
Guoyu Ren ◽  
Botao Zhou ◽  
...  

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