Extreme Cold Waves Research Articles

Analyzing the effects of extreme cold waves on urban water supply network safety: A case study from 2020 to 2021

Urban water supply networks are crucial for the transportation of water resources. However, with the increasing frequency and severity of cold wave disasters linked to climate change, the impact on water supply systems has become a critical concern. These impacts include pipe failures, customer water outages, and challenges in meeting peak winter water demand. To address this, our study analyzes data from cold waves in Shanghai from late 2020 to early 2021. We statistically examined daily water supply volume, pressure, and pipe failures to detect abnormal changes. We also analyzed pipe failure rates based on different characteristics to identify which pipes are most vulnerable to cold wave damage. Understanding the winter cold wave's effects can help water companies prioritize maintenance on aging pipes before such events, reducing damage and improving service. This research adds to the understanding of climate change's impact on urban infrastructure and provides valuable insights for global water companies to optimize their maintenance strategies.

Internal Variability Dominated the Extreme Cold Wave Over North America in December 2022

AbstractIn December 2022, North America experienced an unprecedented extreme cold event. However, the underlying physical mechanisms of this cold wave, and the extent to which it is driven by internal variability or external forcing, are not fully understood. Using ERA5 reanalysis data and the HadGEM3‐A‐N216 attribution simulations, we identified internal variability as the main cause, contributing −5.14 K to surface air temperature (SAT) anomalies in North America. External forcing slightly mitigated the cold by 0.42 K. An internally generated wave train from the North Pacific, influenced in combination by Pacific‐North American (PNA) and North Pacific Oscillation (NPO) teleconnection patterns, initiated this intense cyclonic event, contributing −2.18 K and −2.12 K to SAT anomalies, respectively. La Niña‐like sea surface temperature anomalies amplified this wave train and resultant cold wave. Additionally, excessive snow cover in the previous November also intensified the December cold anomalies by enhancing surface albedo and reducing solar radiation.

철도산업과 기후변화대응

The railroad industry is the best means of transportation to respond to climate change, as it is more energy efficient than the automobile and aircraft industries and emits about six times less greenhouse gases. As of 2018, the transportation sector of railroads emits 2.6% of greenhouse gases, but greenhouse gases should be reduced by converting diesel locomotives to new and renewable energy locomotives and electric locomotives. However, the Framework Act on the Railway Industry, the Railroad Safety Act, the Railroad Construction Act, and the Railroad Business Act do not have legal and institutional mechanisms to respond to climate change or adapt to the climate crisis. Review the legislation and precedents of France and the United States to seek implications for Korea. The Framework Act on the Railway Industry shall establish and implement the national freight and passenger transport sharing rate and the greenhouse gas reduction target, and shall be improved to include matters on climate change and response to the climate crisis in the national policies and basic plans. The Railway Construction Act should also monitor the effects of climate change, such as extreme heat waves, extreme cold waves, extreme strong winds (types), extreme floods, and extreme wildfires, analyze the cost-benefit analysis of adverse effects on railway infrastructure to build them in advance, and maintain them to improve the quality of railway infrastructure, and include climate change response and adaptation to the climate crisis in the railway network plan. The Railway Business Act and the Railroad Safety Act should be revised to ban the operation of diesel locomotives in stages, such as California and the United Kingdom, to raise funds for the conversion of diesel locomotives to environment-friendly locomotives, report their status to the Minister of Land, Infrastructure and Transport, and stipulate that diesel locomotives cannot be idled for more than 30 minutes. Finally, railway stations and structures should be installed with geothermal power plants and solar power plants, and certified as carbon-zero buildings.

Synoptic dynamics of cold waves over north India: Underlying mechanisms of distinct cold wave conditions

The cold air outbreaks in the northern parts of India exert significant impacts on human health, energy, agriculture and transportation. In this study, we investigate the synoptic dynamics of cold waves and their linkages to large scale circulations for the winter period from 1982 to2020. Cold waves are classified into normal and intense (NCWs and ICWs) based on intensity and we examine the underlying mechanisms of formation and their atmospheric drivers. Notably, the spatial extent of the ICWs is almost double than that of normal ones thereby having the potential to affect a wider population. The NCWs are often influenced by western disturbances, leading to the inflow of cold air from Siberia (a region of shallow high). In contrast, ICWs are mostly linked to the presence of an omega block over the Ural-Siberian region. The downstream portion of the Ural block favours the inflow of cold northerlies into north India, leading to cold air advection and extreme cold wave conditions. The influence of Arctic warming for ICWs is further confirmed through a prominent Quasi-Resonant Amplification (QRA) fingerprint. Furthermore, La Niña condition seems to play a crucial role in triggering ICWs over north India. During La Niña, the prominent low level cyclonic anomaly helps in advecting the cold air from the higher latitudes into the country. The frequency as well as the duration of cold wave events are also found to be higher in La Niña years compared to El Niño and neutral years. The trend analysis of cold wave events over north India reveals a significant decrease in the frequency, duration and intensity during the analysis period due to a combination of various factors such as rising winter minimum temperatures (due to global warming), decreasing number of synoptic winter weather systems and Arctic amplification.

Guijing2501 (Citrus unshiu) Has Stronger Cold Tolerance Due to Higher Photoprotective Capacity as Revealed by Comparative Transcriptomic and Physiological Analysis and Overexpression of Early Light-Induced Protein

Cold is one of the major limiting factors for citrus production, particularly extreme cold waves. Therefore, it is of great importance to develop cold-tolerant varieties and clarify their cold tolerance mechanisms in citrus breeding. In this study, comparative transcriptomic and physiological analyses were performed to dissect the cold tolerance mechanism of Guijing2501 (GJ2501), a new satsuma mandarin (Citrus unshiu) variety with about 1 °C lower LT50 (the median lethal temperature) relative to Guijing (GJ). The physiological analysis results revealed that GJ2501 is more cold-tolerant with less photoinhibition, PSII photodamage, and MDA accumulation, but higher POD activity than GJ under cold stress. Comparative transcriptomic analysis identified 4200 DEGs between GJ and GJ2501, as well as 4884 and 5580 up-regulated DEGs, and 5288 and 5862 down-regulated DEGs in response to cold stress in GJ and GJ2501, respectively. “Photosynthesis, light harvesting” and “photosystem” were the specific and most significantly enriched GO terms in GJ2501 in response to cold stress. Two CuELIP1 genes (encoding early light-induced proteins) related to the elimination of PSII photodamage and photoinhibition were remarkably up-regulated (by about 1000-fold) by cold stress in GJ2501 as indicated by RT-qPCR verification. Overexpression of CuELIP1 from GJ2501 in transgenic Arabidopsis protected PSII against photoinhibition under cold stress. Taken together, the cold tolerance of GJ2501 may be ascribed to its higher photoprotective capacity under cold stress.

Features of Local Finite-Amplitude Wave Activity during Extreme Cold Waves over Eastern China

Abstract The frequent occurrence of extreme cold waves under climate change has attracted widespread attention. Based on the Japanese 55-year Reanalysis daily dataset from 1958 to 2021, we use a newly developed dynamic metric, the local finite-amplitude wave activity (LWA), to explore the precursory signals, outburst conditions, and key dynamic features of extreme cold waves over eastern China from the perspective of synoptic climatology. The statistical results show that approximately 40% of extreme cold waves have the following features. First, the formation of significant positive LWA anomalies over the Balkhash–Baikal region is an evident precursory signal, which is accompanied by significant cold surface air temperature anomalies that accumulate over mid- and high-latitude Eurasia. Second, the appearance of extreme positive LWA anomalies over the region east of Lake Baikal (ELB) is necessary for subsequent outbursts of extreme cold waves. These extreme positive LWA anomalies indicate the meridionally enhanced planetary trough over East Asia and advection of the accumulated cold air masses southeastward to eastern China. Third, the evident positive change in the LWA anomalies over the ELB is mainly attributable to the convergence of the zonal LWA flux due to the zonal wind in the eddy-free state and Stokes drift flux over the eastern area of the ELB and the convergence of the meridional eddy heat flux over the western area. This study demonstrates that the LWA could be used as a simple and feasible metric for monitoring and forecasting extreme cold waves. Significance Statement Enhanced waviness in circulation usually occurs before and during the outburst of extreme cold waves over eastern China. With a state-of-the-art diagnostic tool, the local finite-amplitude wave activity (LWA), the present study reveals both precursory signals and outburst conditions of these extreme cold events from the perspective of synoptic climatology. This study not only deepens our understanding of the dynamic process for extreme cold events over eastern China but also offers a method for monitoring and forecasting those extreme events. Our work also provides a method for studying other extreme climate events that are closely related to large-amplitude circulation waviness over the middle and high latitudes.

Objective Identification Method of Cold-Front Precipitation in Winter Half Years over East Asia

Cold front is an important weather system that produces precipitation in East Asia. Under the background of global warming, extreme precipitation caused by cold fronts presents a significant increasing trend. Hence, it is very important to quantify the cold-front precipitation that may cause great damages. In this study, an objective identification method is proposed for cold-front precipitation, which can objectively identify the precipitation area affected by cold fronts. Then, the climatological characteristics and trends of cold-front precipitation over East Asia in the winter half years from 1989 to 2018 are investigated by using the ERA-5 reanalysis dataset. Based on the dataset of cold fronts and frontal zones, this method automatically distinguishes the precipitation area affected by cold fronts to quantitatively estimate cold-front precipitation. The results show that this identification method can well describe cold-front activities and associated precipitation during an extreme cold wave event that occurred in southern China in January 2016. In the past 30 years, cold fronts have significantly contributed to the precipitation in East Asia in winter half years. The areas with the maximum cold-front precipitation and maximum contribution rate of cold-front precipitation to total precipitation are located in the North Pacific storm track, cold-front precipitation exceeds 700 mm, and the contribution of cold-front precipitation to total precipitation exceeds 60%. In addition, the contribution rates of cold-front precipitation are also relatively large in the midlatitudes of East Asia, especially in North China and Northeast China, where cold-front precipitation accounts for 50%–60% of total precipitation. In East Asia, the total precipitation in autumn is greater than that in winter; however, cold-front precipitation and its contribution rate in winter are significantly more and larger than those in autumn. As the cold-frontal activity is more frequent and intense in winter, the rainfall in winter depends more on cold fronts. In the past 30 years, the trends of cold-front precipitation and total precipitation are consistent in most parts of East Asia, indicating that cold-front precipitation makes a great contribution to the trend of total precipitation in winter half years.

A Statistical Linkage between Extreme Cold Wave Events in Southern China and Sea Ice Extent in the Barents-Kara Seas from 1289 to 2017

A Statistical Linkage between Extreme Cold Wave Events in Southern China and Sea Ice Extent in the Barents-Kara Seas from 1289 to 2017

Short-term impact of an extreme weather event on the threatened Dupont’s LarkChersophilus duponti

SummaryThe frequency and intensity of extreme weather events represent a threat for biological diversity and are expected to increase in many regions over the following decades due to climate change. Our current knowledge about the impact of extreme weather events on the population dynamics of bird species is very limited. Here, we evaluated the impact of an extreme winter snowstorm on the abundance of 14 populations of the threatened Dupont’s LarkChersophilus duponti, a resident bird whose European population is restricted to Spain. We found a drastic and significant population decline in the next reproductive season following the extreme weather event. During the control period (2017–2020) the species suffered an overall annual decline of 19.4% (±5.0, SE). However, the overall annual decline after the storm was 67.6% (±9.4, period 2019–2021), with a mean decline of 66.5% (±15.9) for seven populations monitored both the year before and the year after the snowstorm (period 2020–2021). The snow covered the ground for over 10 days in central and eastern Spain, which together with a subsequent extreme cold wave could have reduced the species ability to find food resources and properly thermoregulate, forcing the species to move to unknown areas. Indeed a few days after the storm, several individuals were reported in areas typically avoided. Such displacements may increase the mortality risk for dispersing individuals, besides the direct effects of the extreme cold event, such as thermal challenges to energy balance or a reduced immune function. We discuss the potential role that extreme weather events may have on the population dynamics and conservation of the species.

Dynamic synergistic effects of large-scale three-dimensional circulation anomalies on the record-breaking cold wave in February 2021 in North America

In contrast to previous studies that mainly focused on the influence of the polar vortex in the horizontal circulation on the local cold air, this study uses the three-pattern decomposition of global atmospheric circulation (3P-DGAC) to reveal the dynamic synergistic effects of horizontal circulation, local meridional circulation, and local zonal circulation on cold waves, by examining the record-breaking extreme cold wave (ECW) in February 2021 across North America. In terms of horizontal circulation, this ECW is preceded by the strengthening of blocking highs over the North Pacific and North Atlantic that force the tropospheric polar vortex edge toward North America, resulting in the development of the North American trough. The strongly northwesterly wind caused by the North American trough strengthens the local meridional circulation over North America, transporting cold Arctic air to the mid-low latitudes. Meanwhile, the local meridional circulation over North America strengthens the ascending motion and subsequently promotes the development of local zonal circulation over the North Atlantic. In turn, the developed local zonal circulation reinforces the blocking highs over the two oceans, slowing the movement of the trough and ridge systems eastward and leading to a long duration for this ECW. The composite analysis further conforms that the vertical sinking motion corresponding to blocking highs over the two oceans is mainly contributed by the local zonal circulation, and the strong local zonal circulation over the North Atlantic could lengthen the duration of the cold wave by strengthening the blocking highs. This study suggests that 3P-DGAC is an effective tool for investigating the three-dimensional structural characteristics of anomalous circulations in ECWs.

Extreme cold wave in early November 2021 in China and the influences from the meridional pressure gradient over East Asia

In early November 2021, China experienced its second strongest cold wave event during 1981–2021. Although the Siberian high is considered the main factor influencing cold wave events in East Asia, it was not extremely strong from 4 to November 9, 2021. The spatial distribution of the correlation coefficients between the sea level pressure and the daily temperature anomalies shows a monopole pattern, with a notable negative centre in the southern part of the Siberian high monitoring domain. However, the correlation between the sea level pressure and temperature drop presents a typical dipole pattern, with a distinct negative centre in the northern monitoring domain and a positive centre in southern East Asia. During the November 2021 super cold wave process, the sea level pressure anomalies display a dipole pattern with a higher centre in the north and a lower centre in the south owing to the northward shift of the Intertropical Convergence Zone. The meridional pressure gradient index clearly reveals the non-negligible effect of subtropical low-pressure on this super cold wave process, indicating its possibly essential supplementary role in enhancing this process. The above findings provide a new understanding of its mechanism and long-range forecasts.

On the Successiveness of the Two Extreme Cold Events in China during the 2020/21 Winter According to Cold Air Trajectories

Two extreme cold air events successively hit China during 28–31 December 2020 (the late 2020 event) and during 6–8 January 2021 (the early 2021 event), which caused great losses. These two events have received extensive attention in relation to synoptic weather systems and remote forcing. Although it has been noted that a near-surface cool condition can greatly impact tropospheric circulation, its role in the successiveness of two such extreme cold waves remains unclear. This study focused on cold air pathways from the Lagrangian perspective, and explored the potential influence of cold air over the key region in terms of connecting the two cold events using a piecewise potential vorticity inversion. With the obtained results, three cold air sources with three corresponding air routes were identified in the two cold events. The northern pathway dominated the late 2020 event, in which the cold air intruded from the eastern Laptev Sea and moved southward to China. In contrast, the early 2021 event was mainly associated with the northwestern pathway in which the cold air came from the Ural Mountains and moved clockwise. Notably, cold air traveling along the western route from western Lake Balkhash arrived at the north of the Tianshan Mountains earlier and amplified the positive height anomaly in situ. Moreover, such an enhanced positive height anomaly moved the direction of the cold air from the northern and northwestern routes southward and thus played a key role in the successiveness of the two extreme cold events.

Cold waves in Terai region of Nepal and farmer’s perception of the effect of fog events and cold waves on agriculture

Cold waves are considered one of the important extreme weather events affecting winter crop production in the Indo-Gangetic Plain (IGP). In spite of media coverage of extreme cold events in the Terai area of Nepal (Nepal section of IGP) in recent years, few studies on this topic were found. This study investigates cold waves and their impact on agriculture during winter in the Terai region of Nepal. Historical daily maximum and minimum temperature data from six stations in the Terai (Dhangadhi, Nepalgunj, Bhairahawa, Simara, Janakpur, and Biratnagar) during 1971–2015 were analyzed to study the occurrence of cold days, cold nights, extreme cold days, extreme cold nights, cold wave days, and extreme cold wave days in the Terai. The average number of cold days per annum ranges from 15.6 to 17.9 days and the extreme cold days per annum ranges from 3.2 to 3.6 days in the Terai. Except for Nepalgunj, all the Terai stations show statistically significant increasing trends in the frequency of cold days and extreme cold days over the last four decades. Similarly, the average number of cold wave days varies from 9.2 to 13.8 per annum and the average number of extreme cold wave days varies from 1.4 to 3.8 days in the Terai region of Nepal. By comparing the co-occurrence of foggy days and cold and extreme cold wave days at Biratnagar, Simara, Bhairahawa, and Nepalgunj airport, it is also observed that most of the cold and extreme cold wave days are also foggy days. The perception of farmers regarding the effect of fog and cold wave events was explored through focus group discussions at Dhanusha and Sunsari districts of Nepal and found that the fog and cold events have significantly affected their winter crops, livestock, and their day-to-day life.

Arctic and Pacific Ocean Conditions Were Favorable for Cold Extremes over Eurasia and North America during Winter 2020/21

Abstract A sequence of extreme cold events occurred across Eurasia and North America during winter 2020/21. Here, we explore the causes and associated mechanisms for the extremely cold temperatures using both observations and large-ensemble simulations. Experiments were conducted with observed ocean surface boundary conditions prescribed globally, and regionally to discern the specific influence of Arctic, tropical Pacific, and North Pacific drivers. Increased likelihood of daily cold extremes in mid-December to mid-January are found in Eurasian midlatitudes in response to reduced Arctic sea ice. Tropical sea surface temperature anomalies, more specifically the La Niña pattern, increased probability of extreme cold over high-latitude Eurasia in early January to early February. Both reduced Arctic sea ice and La Niña increased the probability of daily cold extremes over western North America in late January to late February. We conclude that a combination of reduced Arctic sea ice, La Niña, and a sudden stratospheric warming in January 2021 were factors in the February 2021 extreme cold wave that caused huge societal disruptions in Texas and the southern Great Plains. Although the magnitude of the simulated cold extremes are relatively small when compared with observed anomalies, the Arctic and Pacific Ocean surface conditions in winter 2020/21 increased the probability of cold days as cold or colder than observed by approximately 17%–43%.

Characteristics of extreme cold wave events over Southwest China and their possible relationship with the North Atlantic SST

Characteristics of extreme cold wave events over Southwest China and their possible relationship with the North Atlantic SST

The Impacts and Adaptation of Climate Extremes on the Power System: Insights from the Texas Power Outage Caused by Extreme Cold Wave

Along with the aggravation of climate change, various weather and climate extreme events (abbreviated as climate extremes) are becoming more frequent. During the transition to the use of clean energy, the power system will show increasingly prominent features such as high ratio of clean energy, high ratio of electrification, and a high proportion of electric and electronic equipment, coupled with summer and winter load peaks. Against this backdrop, this paper studies the impacts of climate extremes on the power system using the Texas power outage as an example, and proposes general adaptation measures to cope with climate extremes. For a start, this paper reviews the power outage in Texas caused by an extreme cold wave across the North America in 2021, and conducts an in-depth analysis of its causes. Then, based on the theoretical framework of disaster risk management, this paper analyzes the weather and climate disaster risks, extreme events, exposure, and vulnerability faced by the power system in the context of climate change and extreme events. Finally, in order to build a new power system, this paper establishes an overall framework for the power system to mitigate and adapt to climate change, and summarizes the key techniques involved in power generation, transmission, distribution, and consumption, as well as key technologies in the fields of power supply, power grid, power load, and energy storage, and the strategies and measures for addressing climate change.

Structure and Large‐Scale Organization of Extreme Cold Wave Events Over the Chinese Mainland During the Boreal Cold Season

AbstractRecent changes in the Earth's climate have led to renewed interest in extreme cold wave (ECW) events. This study identifies the ECW patterns over the Chinese mainland, their corresponding large‐scale meteorological patterns (LMPs) and their favorable planetary wave patterns over 1961–2015. A self‐organizing map classifies ECWs into northeast, nationwide, northwest–south and Qinghai–Tibetan Plateau clusters. The cold anomalies are primarily contributed by the anomalous wind advecting climatological mean temperature for the leading three clusters, but diabaitic heating for the Qinghai–Tibetan Plateau cluster. The associated LMPs are primarily characterized by a dipole with a positive height anomaly over Siberia and a negative height anomaly extending from Japan to the Iranian Plateau, which displaces southwestward among the four ECW clusters. The LMPs induce anomalous northerly flows extending from the upper troposphere to the near‐surface, which deepen the negative height anomaly southwestward from the East Asian trough and accumulate cold air masses over the key regions within the dipole that are phase‐locked with the LMPs (i.e., baroclinic growth). Such baroclinic growth of the LMP is larger during periods of a planetary wave (wavenumbers 1–5) resembling the Northern Annular Mode (NAM). Meanwhile, the negative (positive) phase of the NAM provides more direct contribution to the LMP of the northeast and nationwide (Qinghai‐Tibetan Plateau) ECW clusters and thus are likely to favor the occurrence of ECWs. The negative phase of NAM‐like planetary waves exhibit a positive trend after the transition year of 1987, and could potentially increase the occurrence frequency of nationwide ECWs.

Consideration of Time Lag of Sea Surface Temperature due to Extreme Cold Wave

Consideration of Time Lag of Sea Surface Temperature due to Extreme Cold Wave

2020/21 record-breaking cold waves in east of China enhanced by the ‘Warm Arctic-Cold Siberia’ pattern

Extreme cold waves frequently occur in east of China that dramatically endanger ecological agriculture, power infrastructure and human life. In this study, we found that the ‘Warm Arctic-Cold Siberia’ pattern (WACS) significantly enhanced cold waves in east of China according to daily composites from 1979 to 2018. During the winter 2020/21, a record-breaking cold wave broke out following a noticeable WACS phenomenon and induced the record-low surface air temperature at 60 meteorological stations since they were established (nearly 60 years). On 3 January 2021, the difference in temperature anomaly between the Barents–Kara Sea and Siberia reached 20 °C, the peak of winter 2020/21. With a shrinking meridional temperature gradient, the atmospheric baroclinicity weakened correspondingly. The accompanying atmospheric anomalies, i.e. the persistent Ural Blocking High and Baikal deep trough effectively transported stronger cold air than the sole impact from Arctic warming. After 4 d, the east of China experienced a severe surface air temperature decrease of more than 8 °C, covering an area of 2500 000 km2. During the same winter, a record-breaking warm event occurred in February 2021, and the ‘Cold Arctic-Warm Eurasia’ pattern also appeared as a precursory signal. Furthermore, on the interannual scale, the connection between winter-mean temperature anomalies in east of China and the WACS pattern also existed and even performed more strongly in both observations and simulation data of CMIP6.

Planetary and synoptic-scale dynamic control of extreme cold wave patterns over the United States

The roles of planetary and synoptic-scale waves in extreme cold wave (ECW) events over the southeastern (SE) and northwestern (NW) United States (US) are studied using a spherical harmonic decomposition in conjunction with piecewise tendency diagnosis (PTD). Planetary waves and synoptic waves jointly work together to initiate ECW events. Notably, the planetary waves not only provide a direct contribution to circulation field enacting ECW events but also alter the background circulation field in such a manner that promotes synoptic waves growth via increases in regional barotropic deformation. The SE-ECW events, concurrent with the Northern Hemisphere annular mode (NAM) negative phase, feature high latitude intensification and subsequent southeastward movement of cold surface air temperature (SAT) anomalies. The planetary-scale pattern provides a sizable contribution to the total wave pattern on both sea level pressure (SLP) and upper level. Moreover, the negative NAM planetary anomaly acts to displace the jet equatorward and thereby increases the barotropic deformation of the synoptic-scale anomaly over southeastern US. PTD confirms that the planetary-scale barotropic deformation plays a key role in deepening the negative height anomaly with a secondary contribution from baroclinic growth. In contrast, NW-ECW events feature a regional SAT cold anomaly that intensified in situ in association with a quasi-stationary positive SLP anomaly with a substantial planetary-scale wave component. The upper level circulation is characterized by a pronounced anomalous ridge over the Gulf of Alaska and a northeast-southwest tilted negative height anomaly to its east. The negative height anomaly axis is orthogonal to the planetary-scale dilatation, result in a stronger planetary barotropic deformation of the incipient negative height anomaly.