scholarly journals Pre-Signal and Influencing Sources of the Extreme Cold Surges at the Beijing 2022 Winter Olympic Competition Zones

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 436
Author(s):  
Ting Ding ◽  
Hui Gao ◽  
Yuan Yuan
Keyword(s):  
Ural Mountain ◽  
Novaya Zemlya ◽  
Asian Winter Monsoon ◽  
Time Profiles ◽  
Second Stage ◽  
Extreme Cold ◽  
Cold Surges ◽  
Backward Analysis ◽  
Air Temperature Anomalies ◽  
Day By Day

The 24th Olympic and Paralympic Winter Games will take place in Beijing in 2022. All three competition zones are vulnerable to extreme cold surges (ECSs), owing to the occurrence of the East Asian winter monsoon. In this paper, a representative competition domain (37.5–42.5° N, 110–120° E) is adopted, with a view to avoiding the differences in both the geographies and the thresholds of ECSs among different zones by considering the probability of simultaneous occurrences. Since 2009, the ECSs in the domain have displayed higher frequency and extremity. Based on all ECS cases in the domain, the dominant circulation is revealed by a quasi “reverse-Ω” pattern, with two strong ridges over the east of the Ural Mountain and the Okhotsk Sea, and a broad, deep trough in East Asia. The influencing sources of the ECSs at the domain could be traced to the Novaya Zemlya by a day-by-day backward analysis. The oblique latitude/longitude–time profiles of both the 500 hPa geopotential height and the 850 hPa air temperature anomalies from the source to the domain clearly indicate that the pre-signal could have a leading influence that exceeds ten days, with a slow accumulation in the first stage and a rapid outburst in the second stage.

scholarly journals Unusual Late-Season Cold Surges during the 2005 Asian Winter Monsoon: Roles of Atlantic Blocking and the Central Asian Anticyclone

2009 ◽  
Vol 22 (19) ◽  
pp. 5205-5217 ◽  
Author(s):  
Mong-Ming Lu ◽  
Chih-Pei Chang
Keyword(s):  
Barents Sea ◽  
Winter Monsoon ◽  
The Arctic ◽  
Late Winter ◽  
Cold Air ◽  
Asian Winter Monsoon ◽  
Central Asian ◽  
East And Southeast Asia ◽  
Cold Surges ◽  
Cold Air Outbreaks

Abstract The highest frequency of late-winter cold-air outbreaks in East and Southeast Asia over 50 years was recorded in 2005, when three strong successive cold surges occurred in the South China Sea within a span of 30 days from mid-February to mid-March. These events also coincided with the first break of 18 consecutive warm winters over China. The strong pulsation of the surface Siberian Mongolia high (SMH) that triggered these events was found to result from the confluence of several events. To the east, a strong Pacific blocking with three pulses of westward extension intensified the stationary East Asian major trough to create a favorable condition for cold-air outbreaks. To the west, the dominance of the Atlantic blocking and an anomalous deepened trough in the Scandinavian/Barents Sea region provided the source of a succession of Rossby wave activity fluxes for the downstream development. An upper-level central Asian anticyclone that is often associated with a stronger SMH was anomalously strong and provided additional forcing. In terms of the persistence and strength, this central Asian anticyclone was correlated with the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) only when SMH is weak (warm winters). During strong SMH seasons (cold winters) the correlation vanishes. However, during late winter 2005 the central Asian anticyclone was strengthened by the Atlantic blocking through both the downstream wave activities and a circulation change that affected the Atlantic and west Asian jets. As a result, the period from mid-February to mid-March of 2005 stands out as a record-breaking period in the Asian winter monsoon.

scholarly journals Evaluation of outdoor thermal comfort conditions in northern Russia over 30-year period: Arkhangelsk region

2020 ◽  
Vol 24 (4) ◽  
pp. 252-260
Author(s):  
Pavel Konstantinov ◽  
Natalia Shartova ◽  
Mikhail Varentsov ◽  
Boris Revich
Keyword(s):  
Cold Stress ◽  
Thermal Comfort ◽  
Arctic Region ◽  
Outdoor Thermal Comfort ◽  
The Arctic ◽  
Novaya Zemlya ◽  
Arkhangelsk Region ◽  
Climatic Period ◽  
Bioclimatic Comfort ◽  
Extreme Cold

The aim of the current paper is to evaluate spatial and temporal characteristics of the distribution of bioclimatic comfort within the Arkhangelsk region (Russian Federation) with two modern indices of thermal comfort: PET and UTCI. Its average values calculated for the modern climatic period (1981-2010) in the monthly mean give a clear picture of spatial heterogeneity for the warmest month (July) and for the coldest one (January). The spatial picture of both indices in July allows us to distinguish three large internal regions: the Arkhangelsk province, the continental part of the Nenets Autonomous Okrug (NAO) and Novaya Zemlya islands (NZ). Winter distribution of thermal discomfort is fundamentally different: the coldest regions (with extreme cold stress) are equally NZ and the Eastern half of NAO; intermediate position is occupied by the West of the NAO and the extreme northeast of the Arkhangelsk region, the highest winter UTCI values are observed in the rest of the region. In Archangelsk-city extreme cold stress in January has repeatability 6.7%, in February-4%, in December-2.2%, respectively. The average number of time points during the year at which thermal stress is not observed is only 19%. Obtained results will be the basis for planning relevant health measures and providing reliable forecasts of the effects of climate change in the Arctic region.

scholarly journals Mathematical Analysis of a COVID-19 Epidemic Model by using Data Driven Epidemiological Parameters of Diseases Spread in India

2020 ◽  
Author(s):  
D Pal ◽  
D Ghosh ◽  
P K Santra ◽  
G S Mahapatra
Keyword(s):  
Incubation Period ◽  
Epidemic Model ◽  
Community Dynamics ◽  
Current Data ◽  
Dynamical Analysis ◽  
Second Stage ◽  
Protection Strategies ◽  
Using Data ◽  
Novel Coronavirus ◽  
Day By Day

This paper attempts to describe the outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) or named as novel coronavirus (COVID-19) via an epidemic model. This dangerous virus has dissimilar effects in different countries in the world. It is observable that the number of new active coronavirus cases is increasing day by day across the globe. India is now in the second stage of COVID-19 spreading, and as a densely populated country, it will be an epidemic very quickly if proper protection / strategies are not under-taken based on the database of the transmission of the disease. This paper is using the current data of COVID-19 for the mathematical modeling and its dynamical analysis. As an alternative of the standard SEIR model, we bring in a new representation to appraise and manage the outbreak of infectious disease COVID-19 through SEQIR pandemic model, which is based on the supposition that the infected but undetected by testing individuals are send to quarantine during the incubation period. During the incubation period if any individual be infected by COVID-19, then that confirmed infected individuals are isolated and the necessary treatments are arranged in proper way so that they cannot taint the other residents in the community. Dynamics of the SEQIR model is presented by basic reproduction number R₀ and the comprehensive stability analysis. Numerical results are depicted through apt graphical appearances using the data of five states and India.

scholarly journals A Climatological Study of Extreme Cold Surges along the African Highlands

2017 ◽  
Vol 56 (6) ◽  
pp. 1731-1738 ◽  
Author(s):  
Caitlin C. Crossett ◽  
Nicholas D. Metz
Keyword(s):  
East Coast ◽  
Cold Season ◽  
Meridional Flow ◽  
Extreme Cold ◽  
Cold Surges ◽  
African Highlands ◽  
Hemisphere Winter ◽  
Type 3

AbstractEquatorward-moving cold surges occur along the lee of high terrain during the cold season. Even though the east coast of Africa features high terrain, little research exists on cold surges along the African highlands despite the fact that these surges could have potentially large agricultural and societal effects. This paper examines a 5-yr climatology of the most extreme African-highlands cold surges spanning the 2008–12 period. During these years, 186 cold surges occurred to the lee of the African highlands, with 84 events extending between 30° and 35°S (type 1), 27 extending between 25° and 30°S (type 2), and 75 extending equatorward of 25°S (type 3) based on the 1000–850-hPa thickness pattern. This climatology reveals that extreme African-highlands cold surges have a climatological maximum in September. Cold surges of type 1 and type 2 tend to occur throughout the Southern Hemisphere winter and spring, whereas surges of type 3 are generally confined to the winter months. These cold surges can last from 2 to 8 days, with the highest frequency of events spanning a 3-day period. A typical cold-surge event features maximum 925-hPa meridional flow of 30.0–39.9 kt (1 kt = 0.51 m s−1) that most frequently advects cold Antarctic air to between 15.0° and 24.9°S and at times as far as the equator.

scholarly journals Classification of Extreme Cold Incursions over South America

2018 ◽  
Vol 33 (5) ◽  
pp. 1183-1203
Author(s):  
Isaque Saes Lanfredi ◽  
Ricardo de Camargo
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Weather Forecasting ◽  
Cold Air ◽  
Synoptic Conditions ◽  
Extreme Cold ◽  
Cold Surges ◽  
Similarities And Differences ◽  
Forcing Mechanisms

Abstract Cold-air incursions across South America present a variety of problems, sometimes by advancing to the Amazon basin and causing agricultural losses related to extreme low-temperature events. The synoptic conditions that produce cold-air incursions are relatively well understood; however, the most affected region depends on the route by which cold air spreads across the continent. Therefore, the classification of extreme cold-air incursions allows a better understanding of the particularities directly related to the aforementioned losses. In this work, similarities and differences among extreme cold surges were found through time series correlation of anomaly temperatures in four selected areas and compositing techniques from ERA-Interim reanalysis datasets, resulting in three distinct patterns: meridional penetration (MP), meridional restriction (MR), and east penetration (EP). The patterns identified here enable a more detailed understanding of the synoptic patterns and forcing mechanisms associated with extreme cold-air incursions and therefore can be used for operational weather forecasting.

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