scholarly journals Association Between Stroke Occurrence And Changes In Atmospheric Circulation 

2020 ◽  
Author(s):  
Jone Vencloviene ◽  
Ricardas Radisauskas ◽  
Daina Kranciukaite-Butylkiniene ◽  
Abdonas Tamosiunas ◽  
Vidmantas Vaiciulis ◽  
...  

Abstract Background: The impact of weather on morbidity from stroke has been analysed in previous studies. As the risk of stroke was mostly associated with changing weather, the changes in the daily stroke occurrence may be associated with changes in atmospheric circulation. The aim of our study was to detect and evaluate the association between daily numbers of ischaemic strokes (ISs) and haemorrhagic strokes (HSs) and the teleconnection pattern.. Methods: The study was performed in Kaunas, Lithuania, from 2000 to 2010. The daily numbers of ISs, subarachnoid haemorrhages (SAHs), and intracerebral haemorrhages (ICHs) were obtained from the Kaunas Stroke Register. We evaluated the association between these types of stroke and the teleconnection pattern by applying Poisson regression and adjusting for the linear trend, month, and other weather variables. Results: During the study period, we analysed 4,038 cases (2,226 men and 1,812 women) of stroke. Of these, 3,245 (80.4%) cases were ISs, 533 (13.2%) cases were ICHs, and 260 (6.4%) cases were SAHs. An increased risk of SAH was associated with a change in mean daily atmospheric pressure over 3.9 hPa (RR=1.49, 95% CI 1.14-1.96), and a stronger El Niño event had a protective effect against SAHs (RR=0.34, 95% CI 0.16-0.69). The risk of HS was positively associated with East Atlantic/West Russia indices (RR=1.13, 95% CI 1.04-1.23). The risk of IS was negatively associated with the Arctic Oscillation index on the same day and on the previous day (RR=0.97, p<0.033). During November-March, the risk of HS was associated with a positive North Atlantic Oscillation (NAO) (RR=1.29, 95% CI 1.03-1.62), and the risk of IS was negatively associated with the NAO index (RR=0.92, 95% CI 0.85-0.99). Conclusions: The results of our study provide new evidence that the North Atlantic Oscillation, Arctic Oscillation, East Atlantic/West Russia, and El Niño-Southern Oscillation pattern may affect the risk of stroke. The impact of these teleconnections is not identical for various types of stroke. Emergency services should be aware that specific weather conditions are more likely to prompt calls for more severe strokes.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jone Vencloviene ◽  
Ricardas Radisauskas ◽  
Daina Kranciukaite-Butylkiniene ◽  
Abdonas Tamosiunas ◽  
Vidmantas Vaiciulis ◽  
...  

Abstract Background The impact of weather on morbidity from stroke has been analysed in previous studies. As the risk of stroke was mostly associated with changing weather, the changes in the daily stroke occurrence may be associated with changes in atmospheric circulation. The aim of our study was to detect and evaluate the association between daily numbers of ischaemic strokes (ISs) and haemorrhagic strokes (HSs) and the teleconnection pattern. Methods The study was performed in Kaunas, Lithuania, from 2000 to 2010. The daily numbers of ISs, subarachnoid haemorrhages (SAHs), and intracerebral haemorrhages (ICHs) were obtained from the Kaunas Stroke Register. We evaluated the association between these types of stroke and the teleconnection pattern by applying Poisson regression and adjusting for the linear trend, month, and other weather variables. Results During the study period, we analysed 4038 cases (2226 men and 1812 women) of stroke. Of these, 3245 (80.4%) cases were ISs, 533 (13.2%) cases were ICHs, and 260 (6.4%) cases were SAHs. An increased risk of SAH was associated with a change in mean daily atmospheric pressure over 3.9 hPa (RR = 1.49, 95% CI 1.14–1.96), and a stronger El Niño event had a protective effect against SAHs (RR = 0.34, 95% CI 0.16–0.69). The risk of HS was positively associated with East Atlantic/West Russia indices (RR = 1.13, 95% CI 1.04–1.23). The risk of IS was negatively associated with the Arctic Oscillation index on the same day and on the previous day (RR = 0.97, p < 0.033). During November–March, the risk of HS was associated with a positive North Atlantic Oscillation (NAO) (RR = 1.29, 95% CI 1.03–1.62), and the risk of IS was negatively associated with the NAO index (RR = 0.92, 95% CI 0.85–0.99). Conclusions The results of our study provide new evidence that the North Atlantic Oscillation, Arctic Oscillation, East Atlantic/West Russia, and El Niño-Southern Oscillation pattern may affect the risk of stroke. The impact of these teleconnections is not identical for various types of stroke. Emergency services should be aware that specific weather conditions are more likely to prompt calls for more severe strokes.


2020 ◽  
Author(s):  
Jone Vencloviene ◽  
Ricardas Radisauskas ◽  
Daina Kranciukaite-Butylkiniene ◽  
Abdonas Tamosiunas ◽  
Vidmantas Vaiciulis ◽  
...  

Abstract Background: The impact of weather on morbidity from stroke was analysed in previous studies. As the risk of stroke was mostly associated with changing weather, the changes in the daily number of strokes may be associated with global changes in atmospheric circulation. The aim of our study was to detect and evaluate the association between daily numbers of ischaemic stroke (IS) and haemorrhagic stroke (HS) and the teleconnection pattern. Methods: The study was conducted in Kaunas city, Lithuania, from 2000 to 2010. The daily numbers of IS, subarachnoid haemorrhages (SAH), and intracerebral haemorrhages (ICH) were obtained from Kaunas Stroke Register. We evaluated the association between these types of stroke and the teleconnection pattern by applying Poisson regression, adjusting for the linear trend, month, and other weather variables. Results: During the study period, we analysed 4,038 cases (2,226 men and 1,812 women) of stroke. Of these, 3,245 (80.4%) cases were IS, 533 (13.2%) cases were ICH, and 260 (6.4%) cases were SAH. A change in mean daily atmospheric pressure of >3.9 hPa was associated with the risk of SAH (RR=1.49, 95% CI 1.14-1.96), and a stronger El Niño event had a protective effect against SAH (RR=0.34, 95% CI 0.16-0.69). The risk of HS was positively associated with East Atlantic/West Russia indices (RR=1.13, 95% CI 1.04-1.23). The risk of IS was negatively associated with Arctic Oscillation indices (RR=0.97, 95% CI 0.94-0.99). During November-March, a positive North Atlantic Oscillation (NAO) was associated with HS (RR=1.29, 95% CI 1.03-1.62), and a negative association between the NAO index and IS (RR=0.92, 95% CI 0.85-0.99) was found. Conclusions: The results of our study provided new evidence that the North Atlantic Oscillation, Arctic Oscillation, East Atlantic/West Russia, and El Niño-Southern Oscillation pattern may affect the risk of stroke. The impact of these teleconnection indices is not identical for different types of stroke. Emergency services should be aware of the fact that specific weather conditions are more likely to prompt calls for more severe strokes.


2020 ◽  
Author(s):  
Jone Vencloviene ◽  
Ricardas Radisauskas ◽  
Daina Kranciukaite-Butylkiniene ◽  
Abdonas Tamosiunas ◽  
Vidmantas Vaiciulis ◽  
...  

Abstract Background: The impact of weather on morbidity from stroke was analysed in previous studies. As the risk of stroke was mostly associated with changing weather, the changes in the daily number of strokes may be associated with global changes in atmospheric circulation. The aim of our study was to detect and evaluate the association between daily numbers of ischaemic stroke (IS) and haemorrhagic stroke (HS) and the teleconnection pattern. Methods: The study was conducted in Kaunas city, Lithuania, from 2000 to 2010. The daily numbers of IS, subarachnoid haemorrhages (SAH), and intracerebral haemorrhages (ICH) were obtained from Kaunas Stroke Register. We evaluated the association between these types of stroke and the teleconnection pattern by applying Poisson regression, adjusting for the linear trend, month, and other weather variables. Results: During the study period, we analysed 4,038 cases (2,226 men and 1,812 women) of stroke. Of these, 3,245 (80.4%) cases were IS, 533 (13.2%) cases were ICH, and 260 (6.4%) cases were SAH. A change in mean daily atmospheric pressure of >3.9 hPa was associated with the risk of SAH (RR=1.49, 95% CI 1.14-1.96), and a stronger El Niño event had a protective effect against SAH (RR=0.34, 95% CI 0.16-0.69). The risk of HS was positively associated with East Atlantic/West Russia indices (RR=1.13, 95% CI 1.04-1.23). The risk of IS was negatively associated with Arctic Oscillation indices (RR=0.97, 95% CI 0.94-0.99). During November-March, a positive North Atlantic Oscillation (NAO) was associated with HS (RR=1.29, 95% CI 1.03-1.62), and a negative association between the NAO index and IS (RR=0.92, 95% CI 0.85-0.99) was found. Conclusions: The results of our study provided new evidence that the North Atlantic Oscillation, Arctic Oscillation, East Atlantic/West Russia, and El Niño-Southern Oscillation pattern may affect the risk of stroke. The impact of these teleconnection indices is not identical for different types of stroke. Emergency services should be aware of the fact that specific weather conditions are more likely to prompt calls for more severe strokes.


2019 ◽  
Vol 19 (16) ◽  
pp. 10787-10800 ◽  
Author(s):  
Juan Feng ◽  
Jianping Li ◽  
Hong Liao ◽  
Jianlei Zhu

Abstract. The high aerosol concentration (AC) over eastern China has attracted attention from both science and society. Based on the simulations of a chemical transport model using a fixed emissions level, the possible impact of the previous autumn North Atlantic Oscillation (NAO) combined with the simultaneous El Niño–Southern Oscillation (ENSO) on the boreal winter AC over eastern China is investigated. We find that the NAO only manifests its negative impacts on the AC during its negative phase over central China, and a significant positive influence on the distribution of AC is observed over south China only during the warm events of ENSO. The impact of the previous NAO on the AC occurs via an anomalous sea surface temperature tripole pattern by which a teleconnection wave train is induced that results in anomalous convergence over central China. In contrast, the occurrence of ENSO events may induce an anomalous shift in the western Pacific subtropical high and result in anomalous southwesterlies over south China. The anomalous circulations associated with a negative NAO and El Niño are not favorable for the transport of AC and correspond to worsening air conditions over central and south China. The results highlight the fact that the combined effects of tropical and extratropical systems play a considerable role in affecting the boreal winter AC over eastern China.


2011 ◽  
Vol 92 (6) ◽  
pp. S1-S236 ◽  
Author(s):  
J. Blunden ◽  
D. S. Arndt ◽  
M. O. Baringer

Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Niño phase at the beginning of the year to a cool La Niña phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin and near-record high North Atlantic basin hurricane activity. The remaining five main hurricane basins experienced below- to well-below-normal tropical cyclone activity. The negative phase of the Arctic Oscillation was a major driver of Northern Hemisphere temperature patterns during 2009/10 winter and again in late 2010. It contributed to record snowfall and unusually low temperatures over much of northern Eurasia and parts of the United States, while bringing above-normal temperatures to the high northern latitudes. The February Arctic Oscillation Index value was the most negative since records began in 1950. The 2010 average global land and ocean surface temperature was among the two warmest years on record. The Arctic continued to warm at about twice the rate of lower latitudes. The eastern and tropical Pacific Ocean cooled about 1°C from 2009 to 2010, reflecting the transition from the 2009/10 El Niño to the 2010/11 La Niña. Ocean heat fluxes contributed to warm sea surface temperature anomalies in the North Atlantic and the tropical Indian and western Pacific Oceans. Global integrals of upper ocean heat content for the past several years have reached values consistently higher than for all prior times in the record, demonstrating the dominant role of the ocean in the Earth's energy budget. Deep and abyssal waters of Antarctic origin have also trended warmer on average since the early 1990s. Lower tropospheric temperatures typically lag ENSO surface fluctuations by two to four months, thus the 2010 temperature was dominated by the warm phase El Niño conditions that occurred during the latter half of 2009 and early 2010 and was second warmest on record. The stratosphere continued to be anomalously cool. Annual global precipitation over land areas was about five percent above normal. Precipitation over the ocean was drier than normal after a wet year in 2009. Overall, saltier (higher evaporation) regions of the ocean surface continue to be anomalously salty, and fresher (higher precipitation) regions continue to be anomalously fresh. This salinity pattern, which has held since at least 2004, suggests an increase in the hydrological cycle. Sea ice conditions in the Arctic were significantly different than those in the Antarctic during the year. The annual minimum ice extent in the Arctic—reached in September—was the third lowest on record since 1979. In the Antarctic, zonally averaged sea ice extent reached an all-time record maximum from mid-June through late August and again from mid-November through early December. Corresponding record positive Southern Hemisphere Annular Mode Indices influenced the Antarctic sea ice extents. Greenland glaciers lost more mass than any other year in the decade-long record. The Greenland Ice Sheet lost a record amount of mass, as the melt rate was the highest since at least 1958, and the area and duration of the melting was greater than any year since at least 1978. High summer air temperatures and a longer melt season also caused a continued increase in the rate of ice mass loss from small glaciers and ice caps in the Canadian Arctic. Coastal sites in Alaska show continuous permafrost warming and sites in Alaska, Canada, and Russia indicate more significant warming in relatively cold permafrost than in warm permafrost in the same geographical area. With regional differences, permafrost temperatures are now up to 2°C warmer than they were 20 to 30 years ago. Preliminary data indicate there is a high probability that 2010 will be the 20th consecutive year that alpine glaciers have lost mass. Atmospheric greenhouse gas concentrations continued to rise and ozone depleting substances continued to decrease. Carbon dioxide increased by 2.60 ppm in 2010, a rate above both the 2009 and the 1980–2010 average rates. The global ocean carbon dioxide uptake for the 2009 transition period from La Niña to El Niño conditions, the most recent period for which analyzed data are available, is estimated to be similar to the long-term average. The 2010 Antarctic ozone hole was among the lowest 20% compared with other years since 1990, a result of warmer-than-average temperatures in the Antarctic stratosphere during austral winter between mid-July and early September.


2012 ◽  
Vol 25 (14) ◽  
pp. 4993-5010 ◽  
Author(s):  
Ying Li ◽  
Ngar-Cheung Lau

Abstract The spatiotemporal evolution of various meteorological phenomena associated with El Niño–Southern Oscillation (ENSO) in the North Pacific–North American–North Atlantic sector is examined using both NCEP–NCAR reanalyses and output from a 2000-yr integration of a global coupled climate model. Particular attention is devoted to the implications of downstream eddy developments on the relationship between ENSO and the atmospheric circulation over the North Atlantic. The El Niño–related persistent events are characterized by a strengthened Pacific subtropical jet stream and an equatorward-shifted storm track over the North Pacific. The wave packets that populate the storm tracks travel eastward through downstream development. The barotropic forcing of the embedded synoptic-scale eddies is conducive to the formation of a flow that resembles the negative phase of the North Atlantic Oscillation (NAO). The more frequent and higher persistence of those episodes during El Niño winters contribute to the prevalence of negative NAO conditions. The above processes are further delineated by conducting a case study for the 2009/10 winter season, in which both El Niño and negative NAO conditions prevailed. It is illustrated that the frequent and intense surface cyclone development over North America and the western Atlantic throughout that winter are associated with upper-level troughs propagating across North America, which in turn are linked to downstream evolution of wave packets originating from the Pacific storm track.


Sign in / Sign up

Export Citation Format

Share Document