scholarly journals Diurnal and Seasonal Variations of Surface Ozone and Its Precursors in the Atmosphere of Yanbu, Saudi Arabia

2014 ◽  
Vol 05 (05) ◽  
pp. 408-422 ◽  
Author(s):  
Hesham A. Al-Jeelani
Keyword(s):  
Saudi Arabia ◽  
Seasonal Variations ◽  
Surface Ozone

scholarly journals Stroke Seasonality and Weather Association in a Middle East Country: A Single Tertiary Center Experience

2021 ◽  
Vol 12 ◽  
Author(s):  
Saeed A. M. Alghamdi ◽  
Mohammed A. Aldriweesh ◽  
Bayan A. Al Bdah ◽  
Muath A. Alhasson ◽  
Sultan A. Alsaif ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Seasonal Variations ◽  
Medical Condition ◽  
Meteorological Data ◽  
Cold Season ◽  
Current Evidence ◽  
Stroke Incidence ◽  
Tertiary Center ◽  
Significant Difference ◽  
Hot Season

Background: Stroke is a medical condition that leads to major disability and mortality worldwide. Some evidence suggests that weather and seasonal variations could have an impact on stroke incidence and outcome. However, the current evidence is inconclusive. Therefore, this study examines the seasonal variations and meteorological influences on stroke incidence and outcome in the largest city in Saudi Arabia.Methods: From February 2016 to July 2019, we retrospectively reviewed data from all patients with acute ischemic (AIS) or hemorrhagic stroke (HS) admitted to the stroke unit in a tertiary academic center in Saudi Arabia. The corresponding daily meteorological data were obtained for the same period. We considered the months from November to March as the cold season and April to October as the hot season.Results: The final cohort included 1,271 stroke patients; 60.89% (n = 774) cases occurred in the hot season, while 39.1% (n = 497) in the cold season. Males accounted for 69.6% (n = 884) of the cases. The proportion of ischemic stroke was 83.2% [hot season 83.9% (n = 649) vs. cold season 82.3% (n = 409)]. We found no statistically significant difference between seasons (hot or cold) in stroke incidence, severity [National Institutes of Health Stroke Scale (NIHSS)], hospital course (pneumonia, thromboembolism, intensive care stay, or length of stay), or outcome [modified Rankin scale (mRS) on discharge and death].Conclusions: In Riyadh, Saudi Arabia, our study found no impact of weather or seasonal variations on stroke incidence, hospital course, or outcomes. However, our findings warrant further research in different country regions.

scholarly journals Seasonal variations of respiratory viruses detected from children with respiratory tract infections in Riyadh, Saudi Arabia

2018 ◽  
Vol 11 (2) ◽  
pp. 183-186 ◽  
Author(s):  
Saad S. Albogami ◽  
Meshal R. Alotaibi ◽  
Saud A. Alsahli ◽  
Emad Masuadi ◽  
Mohammad Alshaalan
Keyword(s):  
Saudi Arabia ◽  
Respiratory Tract ◽  
Seasonal Variations ◽  
Respiratory Tract Infections ◽  
Respiratory Viruses ◽  
Tract Infections

Spatial and seasonal variations of surface ozone formation regime and source attributions in the Guanzhong Basin, China

2020 ◽  
Author(s):  
Guohui Li ◽  
Ruonan Wang ◽  
Naifang Bei ◽  
Jiarui Wu ◽  
Suixin Liu ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Surface Ozone ◽  
Ozone Formation ◽  
Guanzhong Basin

scholarly journals A climatology of surface ozone in the extra tropics: cluster analysis of observations and model results

2007 ◽  
Vol 7 (4) ◽  
pp. 12541-12572 ◽  
Author(s):  
O. A. Tarasova ◽  
C. A. M. Brenninkmeijer ◽  
P. Jöckel ◽  
A. M. Zvyagintsev ◽  
G. I. Kuznetsov
Keyword(s):  
Seasonal Variations ◽  
Surface Ozone ◽  
Transport Processes ◽  
Diurnal Variability ◽  
Model Cluster ◽  
Seasonal Maximum ◽  
Polluted Sites ◽  
Summer Maximum ◽  
The One ◽  
Spring Maximum

Abstract. Important aspects of the seasonal variations of surface ozone are discussed. The underlying analysis is based on the long-term (1990–2004) ozone records of Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP) and the World Data Center of Greenhouse Gases which do have a strong Northern Hemisphere bias. Seasonal variations are pronounced at most of the 114 locations for any time of the day. Seasonal-diurnal variability classification using hierarchical agglomeration clustering reveals 5 distinct clusters: clean/rural, semi-polluted non-elevated, semi-polluted semi-elevated, elevated and polar/remote marine types. For the cluster "clean/rural" the seasonal maximum is observed in April, both for night and day. For those sites with a double maximum or a wide spring-summer maximum, the one in spring appears both for day and night, while the one in summer is more pronounced for daytime and hence can be attributed to photochemical processes. For the spring maximum photochemistry is a less plausible explanation as no dependence of the maximum timing is observed. More probably the spring maximum is caused by dynamical/transport processes. Using data from the 3-D atmospheric chemistry general circulation model ECHAM5/MESSy1 covering the period of 1998–2005 a comparison has been performed for the identified clusters. For the model data four distinct classes of variability are detected. The majority of cases are covered by the regimes with a spring seasonal maximum or with a broad spring-summer maximum (with prevailing summer). The regime with winter–early spring maximum is reproduced by the model for southern hemispheric locations. Background and semi-polluted sites appear in the model in the same cluster. The seasonality in this model cluster is characterized by a pronounced spring (May) maximum. For the model cluster that covers partly semi-elevated semi-polluted sites the role of the photochemical production/destruction seems to be overestimated. Taking into consideration the differences in the data sampling procedure the carried out comparison demonstrates the ability of the model to reproduce the main regimes of surface ozone variability quite well.

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