Severe Cold Event Research Articles

Comparative physiology and transcriptome response patterns in cold-tolerant and cold-sensitive varieties of Solanum melongena

BackgroundClimate change has led to severe cold events, adversely impacting global crop production. Eggplant (Solanum melongena L.), a significant economic crop, is highly susceptible to cold damage, affecting both yield and quality. Unraveling the molecular mechanisms governing cold resistance, including the identification of key genes and comprehensive transcriptional regulatory pathways, is crucial for developing new varieties with enhanced tolerance.ResultsIn this study, we conducted a comparative analysis of leaf physiological indices and transcriptome sequencing results. The orthogonal partial least squares discriminant analysis (OPLS-DA) highlighted peroxidase (POD) activity and soluble protein as crucial physiological indicators for both varieties. RNA-seq data analysis revealed that a total of 7024 and 6209 differentially expressed genes (DEGs) were identified from variety “A” and variety “B”, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment of DEGs demonstrated that the significant roles of starch and sucrose metabolism, glutathione metabolism, terpenoid synthesis, and energy metabolism (sucrose and starch metabolism) were the key pathways in eggplant. Weighted gene co-expression network analysis (WGCNA) shown that the enrichment of numerous cold-responsive genes, pathways, and soluble proteins in the MEgrep60 modules. Core hub genes identified in the co-expression network included POD, membrane transporter-related gene MDR1, abscisic acid-related genes, growth factor enrichment gene DELLA, core components of the biological clock PRR7, and five transcription factors. Among these, the core transcription factor MYB demonstrated co-expression with signal transduction, plant hormone, biosynthesis, and metabolism-related genes, suggesting a pivotal role in the cold response network.ConclusionThis study integrates physiological indicators and transcriptomics to unveil the molecular mechanisms responsible for the differences in cold tolerance between the eggplant cold-tolerant variety “A” and the cold-sensitive variety “B”. These mechanisms include modulation of reactive oxygen species (ROS), elevation in osmotic carbohydrate and free proline content, and the expression of terpenoid synthesis genes. This comprehensive understanding contributes valuable insights into the molecular underpinnings of cold stress tolerance, ultimately aiding in the improvement of crop cold tolerance.

Effect of a severe cold spell on overwintering survival of an invasive forest insect pest

Cold temperatures can play a significant role in the range and impact of pest insects. Severe cold events can reduce the size of insect outbreaks and perhaps even cause outbreaks to end. Measuring the precise impact of cold events, however, can be difficult because estimates of insect mortality are often made at the end of the winter season. In late January 2023 long-term climate models predicted a significant cold event to occur over eastern North America. We used this event to evaluate the immediate impact on hemlock woolly adelgid (Adelges tsugae Annand) overwintering mortality at four sites on the northern edge of the insects invaded range in eastern North America. We observed complete mortality, partial mortality and no effects on hemlock woolly adelgid mortality that correlated with the location of populations and strength of the cold event. Our data showed support for preconditioning of overwintering adelgids having an impact on their overwintering survival following this severe cold event. Finally, we compared the climatic conditions at our sites to historical weather data and previous observations of mortality in Nova Scotia. The cold event observed in February 2023 resulted in the coldest temperatures observed at these sites, including the period within which hemlock woolly adelgid invaded, suggesting cold conditions, especially under anthropogenic climate forcing, may not be a limiting factor in determining the ultimate northern range of hemlock woolly adelgid in eastern North America.

Has substantial sea ice loss along the Siberian coast contributed to the 2020/2021 winter cold wave in China?

In winter 2020/2021, several episodes of cold air outbreaks have wreaked havoc across much of China, resulting in exceptionally low temperatures over northern-to-southeastern China. Our analysis shows that the anomalous circulation leading to the cold wave in China was characterized as: (a) a strengthening of the Siberian high, (b) a deepening of the East Asian trough, and (c) a weakening of the stratospheric polar vortex. Prior to the winter, in summer and autumn, the largest sea ice loss along the Siberian coast was observed. We therefore address the question whether the substantial sea ice loss has contributed to the cold wave. First, applying singular value decomposition (SVD) analysis, we find strong coherence between the autumn Arctic sea ice coverage and temperatures over the central-to-east Asian region with the sea ice component (SVD1_SIC) reaching a record high in 2020 and displaying a decadal shift around 2005. Associated with both the interannual and decadal variations of the SVD1_SIC, there are similar circulation anomalies as described in (a), (b) and (c) above. Second, applying self-organizing maps, wintertime daily air temperatures are clustered into nine nodes with Node-1 mostly resembling “warm Arctic, cold Eurasia” pattern. The frequency of Node-1 shows a similar decadal shift as observed in SVD_SIC1 above, with a correlation of about 0.56. Associated with Node-1, the circulation anomalies are consistent with features highlighted in (a), (b) and (c) above. Thus, taking all the evidence into account, we conclude that the substantial sea ice loss along the Siberian coast contributed significantly to the 2020/2021 winter cold wave in China. The mechanism behind the contribution in this study highlights that the Arctic sea ice loss is favourable for certain circulation patterns on climate timescale, reinforcing disruptive chain of reactions on weather timescale, and leading to severe cold events.

Impacts of Sudden Stratospheric Warming on Extreme Cold Events in Early 2021: An Ensemble‐Based Sensitivity Analysis

AbstractImpacts of sudden stratospheric warming (SSW) on three severe cold events (C1–C3) over Northern Hemisphere in early 2021 were investigated using subseasonal‐to‐seasonal ensemble forecasts. The SSW was characterized by successive displacement and split of the stratospheric polar vortex (SPV). Ensemble‐based sensitivity analyses showed that C1 over Siberia and C2 over western Canada were more related to SPV variations at a lead time of 1–2 weeks than C3 over central U.S. Within ensemble forecasts, a more elongated SPV with higher geopotential height over northern Eurasia were conducive to C1, whereas a SPV with the more poleward retreat from displacement contributed to C2. The forecast accuracy of stratospheric heights over the sensitive region at 2 weeks lead was significantly correlated with the forecast skill of the tropospheric circulation pattern preceding C1, implying that prediction of specific cold weather events may be improved by a better forecast of key features in SPV variations.

Effects of Barents–Kara Seas ice and North Atlantic tripole patterns on Siberian cold anomalies

Possible physical routes are presented that link the decline in sea-ice concentration (SIC) in the Barents–Kara Seas (BKS), the sea surface temperature anomaly in the pattern of the North Atlantic tripole (NAT), and the Siberian cold anomaly in boreal winter, via mid–high-latitude circulation anomalies mainly characterized by Ural blocking (UB). It is found that the Siberian cold anomalies with BKS SIC loss are mostly related to UB, while those without significant BKS SIC loss are significantly correlated with the North Atlantic Oscillation (NAO). The negative/positive-phase NAT (NAT−/NAT+) exerts its impact on the cold/warm anomalies over northern Eurasia through coupling with the negative/positive-phase NAO (NAO−/NAO+). In particular, a strong NAT− winter tends to cause a cold anomaly shifting southwards from the polar area to mid–high-latitude of Eurasia, producing a severe cold event over Siberia. From the perspective of intraseasonal atmospheric circulation, a UB event under NAT− winter leads to a more intense Siberian cold anomaly than one under NAT+, suggesting a vital role played by the NAO in forming cold conditions in Siberia. Considering the effects of BKS sea-ice variation, it is revealed that the UB-related Siberian cold anomaly tends to achieve its maximum strength in a NAT− winter when the BKS SIC declines. However, for winters with sea ice loss in BKS but a weak NAT+, the UB-related Siberian cold anomaly shows southward displacement. It is also found that strong NAT− coupling with a strong NAO− can cause cold conditions in Siberia without the need for a BKS SIC decline and long-lived UB, and this explains 75% of the cold Siberian winters in the context of increased BKS SIC.

Morphological response of the red palm weevil, Rhynchophorus ferrugineus, to a transient low temperature analyzed by computer tomography and holographic microscopy.

The red palm weevil (RPW), Rhynchophorus ferrugineus, is one of the worst palm pests worldwide. Our study aims to assess its internal and external morphological response to a sudden but transient decrease in the environmental temperature. Wild pre-pupae were subjected for 7 days to either low (5.0±0.5°C) or ambient temperature (23±1°C). Such conditions mimic a thermal anomaly happening in the larval stage most exposed to environmental factors. We quantified the changes undergone at: 1) the internal morphology, by X-Ray Computer Tomography (CT); 2) the 3-D integument' architecture, by Digital Holographic Microscopy (DHM); and 3) the glucose in hemolymph as a potential endogenous cryoprotectant. From X-ray CT we found that both pre-pupae subjected to cold and those remaining at ambient temperature follow a development where their fat body content decreases while a thick and dense cuticle is formed. There was no difference between both groups in the rate of change of fat body/dense tissues. Nevertheless, the cold group presents a slight developmental delay at the level of hemolymph content. Through DHM we again obtained that pre-pupae subjected to cold have not experienced a stop in their development. However, a more obvious developmental delay is now observed in this group at the level of the integumental roughness. Finally, regarding glucose, we found similar levels in control and ambient temperature larvae, while it was clearly increased in 51,7% of those subjected to cold. Our whole results provide morphological and biochemical evidence showing that the larval-pupal transition of the RPW continues almost undisturbed even during the quiescent state induced by a sudden and severe cold event. Nevertheless, a certain developmental delay is observed in both internal and external morphology. Additionally, the increased glucose level only found in the cold group suggests that glucose is part of the RPW cold tolerance strategy.

Non-freezing cold event stresses can cause significant damage to mangrove seedlings: assessing the role of warming and nitrogen enrichment in a mesocosm study

Mangroves are expanding poleward along coastlines globally as a response to rising temperatures and reduced incidence of freezing under climate change. Yet, knowledge of mangrove responses to infrequent cold events in the context of climate warming and regional nitrogen (N)-enriched eutrophication is limited. We conducted a mesocosm experiment in which the seedlings of two mangrove species (A. marina and B. gymnorrhiza) were grown either at ambient temperature or under warming with and without nitrogen (N) loading. During a short winter period, an unusually severe cold event occurred with the lowest temperature of 2 °C in the experimental region. We took this unique opportunity to assess possible response of these mangrove species to the cold stress under various environmental conditions. The cold event caused various degrees of damage to the seedlings of both mangrove species, with the warming treatment seemingly protecting leaves and branches from the cold damage. However, the warming treatment did not buffer mangroves to mortality from the low temperature stress in either species. The cold event resulted in significant decreases in seedling growth rates and net ecosystem CO2 uptake in the post-cold period relative to the pre-cold period, although the cold event did not alter the effects of warming treatment on these parameters of both mangrove species. The cold event differentially altered physiological responses of the two species growing under N loading, with the seedlings of A. marina growing in higher N concentrations having a reduced growth response after the cold event, whereas those of B. gymnorrhiza showed no change in post-cold period versus pre-cold period growth. Our results suggest that cold events may play a pivotal role in regulating mangrove survival and growth even under future warming scenarios. Two mangrove species exhibited differential survival and growth responses to the cold event at different N concentrations, which may have implications for how we can restore and conserve mangroves among the world’s eutrophied sub-tropical estuaries and with future warming.

Differing mechanisms for the 2008 and 2016 wintertime cold events in southern China

AbstractSouthern China was hit by a severe cold event during January 21–25, 2016, characteristic of a drastic and sudden temperature drop, with new records of low temperatures set in widespread areas. This cold event was dynamically linked to the activity of the Arctic oscillation (AO) whose evolution led the event by about 2 weeks. Different from this short lasting but intense cold event in 2016, another cold event in the 2008 winter lasted much longer and occurred in tandem with freezing precipitation. Their differences in the duration and precipitation are essentially determined by differing behaviours of blocking highs at mid–high latitudes, the India–Burma Trough and the western Pacific subtropical high. The rapid southward invasion of cold air masses during the 2016 event resulted from the rapid decay of the blocking high, which emanated wave energies downstream and likewise lost wave energies to the local mean flow. By contrast, during the 2008 cold event, continuous upstream wave energy dispersion recurrently stimulated disturbances in the blocking domain, which then extracted energies from the mean flow efficiently to survive markedly longer. Moreover, in the 2008 case, the deepening of the India–Burma Trough and the westward extension of the western Pacific subtropical high jointly enhanced the moisture transport, leading to the freezing rain. This favourable configuration for precipitation was absent in the 2016 case, dictating its dry nature accordingly.

Two Impacts of Arctic Rapid Tropospheric Daily Warming From Different Warm Temperature Advection on Cold Winters Over Northern Hemisphere

AbstractA number of previous studies show that the long‐term Arctic winter warming causes severe cold over East Asia and North America. We use the atmospheric data from National Centers for Environmental Prediction/National Center for Atmospheric Research Reanalysis to define the Arctic rapid tropospheric daily warming (RTDW) events that in one day, Arctic average 1,000‐hPa air temperature is over 3σ warmer anomaly in situ winter. We find that main warm temperature advection of the RTDW events is from Atlantic Ocean and Pacific Ocean, named the Atlantic pattern and the Pacific pattern, respectively. The RTDW events of different warm temperature advection have different vertical distributions of warming. Therefore, different polar vortex splitting is induced and the splitting of polar vortex means movement of the cold air mass. The impacts of RTDW events on the Northern Hemisphere cold winter are mainly through the Asia‐Europe path caused by the Atlantic pattern and the North America path caused by the Pacific pattern. As for the Asia‐Europe path, the cold air invades the northern hemisphere from northwest Europe to Southeast Asia throughout the entire Eurasian continent. In the case of the North America path, the negative temperature anomalies are located in the west of Canada and America. The different warm temperature advection of RTDW events leads to different regions of the polar cold air mass invasion through different paths. Our results may help find out where the severe cold events impact on after the Arctic RTDW events with the occurrence of different warm temperature advection.

Resilience of a tropical sport fish population to a severe cold event varies across five estuaries in southern Florida

AbstractFor species that are closely managed, understanding population resilience to environmental and anthropogenic disturbances (i.e., recovery trajectories across broad spatial areas) can guide which suite of management actions are available to mitigate any impacts. During January 2010, an extreme cold event in south Florida caused widespread mortality of common snook, Centropomus undecimalis, a popular sport fish. Interpretation of trends using fishery‐independent monitoring data in five south Florida estuaries showed that changes in catch rates of adult snook (>500 mm standard length) varied between no effects postevent to large effects and 4‐yr recoveries. The reasons for the variation across estuaries are unknown, but are likely related to differences in estuary geomorphology and habitat availability (e.g., extent of deep rivers and canals) and differences in the proportions of behavior contingents (i.e., segments of the population that use divergent movement tactics) that place snook in different areas of the estuary during winter. Emerging awareness of the presence of behavior contingents, identification of overwintering sites, and improvements of abundance indices in remote nursery habitats should provide a better understanding of population resilience to disturbance events for snook. Given that changes in the frequency of short‐lived, severe cold events are currently unknown, the findings and management actions described here for a tropical species living at the edge of its distribution should be useful to scientists forecasting the effects of climate change.

Winter cold tolerance and the geographic range separation of Bromus tectorum and Bromus rubens, two severe invasive species in North America

AbstractThe invasive grasses Bromus rubens and Bromus tectorum are responsible for widespread damage to semiarid biomes of western North America. Bromus. tectorum dominates higher and more northern landscapes than its sister species B. rubens, which is a severe invader in the Mojave desert region of the American Southwest. To assess climate thresholds controlling their distinct geographic ranges, we evaluated the winter cold tolerance of B. tectorum and B. rubens. Freezing tolerance thresholds were determined using electrolyte leakage and whole‐plant mortality. The responses of the two species to winter cold and artificial freezing treatments were similar in 2007–2008 and 2009–2010. When grown at minimum temperatures of 10 °C, plants of both species had cold tolerance thresholds near −10 °C, while plants acclimated to a daily minimum of −10 to −30 °C survived temperatures down to −31 °C. In the winter of 2010–2011, a sudden severe cold event on December 9, 2010 killed all B. rubens populations, while B. tectorum was not harmed; all tested plants were 7–8 weeks old. Controlled acclimation experiments demonstrated that 8‐week‐old plants of B. rubens had a slower acclimation rate to subzero temperatures than B. tectorum and could not survive a rapid temperature drop from 1 to −14 °C. Four‐month‐old B. rubens populations were as cold tolerant as B. tectorum. Our results show that severe and sudden freeze events in late autumn can kill young plants of B. rubens but not B. tectorum. Such events could exclude B. rubens from the relatively cold, Intermountain steppe biome of western North America where B. tectorum predominates.

Biologging to examine multiple life stages of an estuarine-dependent fish

To better understand habitat use through ontogeny, this paper synthesizes 7 yr of biologging research on the adult and juvenile life stages of an estuarine-dependent fish, the com- mon snook Centropomus undecimalis in Charlotte Harbor, Florida, USA. During 3 yr of telemetry research in a putative nursery habitat (mangrove creeks), we resighted 85.4% of 1924 juvenile snook marked after, and 13.5% of 2191 juveniles marked prior to, deployment of a telemetry array. During 4 yr of research in spawning habitat (barrier island beaches), we used seine nets and recaptured 5.63% of 3304 marked adult snook. After analyzing these concurrent data sets, we found significant intra- and interannual site fidelity patterns in both life stages, while document- ing movement between juvenile and adult spawning habitats. Additionally, this tag-based approach allowed an investigation of the relative effects of a severe cold event, which reduced apparent survival by 22.6 to 38.3% for juveniles and 97.8 to 98.5% for adults. This work presents data within and between life stages that are critical to understanding processes affecting onto - genetic habitat use and connectivity and underscores the importance of incorporating within- stage fidelity and emigration in studies on ontogeny.

Effects of a Severe Cold Event on the Subtropical, Estuarine-Dependent Common Snook, Centropomus undecimalis

The effects of infrequent disturbance events on marine fishes are often difficult to determine, due largely to lack of sufficient pre— and post—disturbance event data. In January 2010, subtropical southwestern Florida (USA) experienced extreme cold for 13 days, which caused extensive mortality of many fish species. The effect of this severe cold event on common snook ( Centropomus undecimalis), an economically important gamefish, was assessed using three years (2007—2009) of pre—event and one year (2010) of post—event data from a tag—recapture program conducted over 28 km of Gulf of Mexico barrier islands of Florida. All metrics pointed to a significant effect of the severe cold event: post—disturbance apparent survival of marked fish was 96—97% lower than pre—disturbance, and post—disturbance common snook abundance was 75.57% and 41.88% less than in 2008 and 2009, the two years immediately pre—event. Although severe cold events have impacted subtropical Florida in the past, these events are infrequent (the previous recorded event was >30 years prior), and documentation of the impacts on common snook have not previously been published.

Responses of the Okhotsk Sea environment and sedimentology to global climate changes at the orbital and millennial scale during the last 350 kyr

We measured productivity proxies (chlorin, carbonate and organic carbon, opal, and biogenic Ba content) and lithophysical proxies (magnetic susceptibility, water content, density, and coarse sediment fraction) in sediment of central Okhotsk Sea core PC-7R. The age model covering the last 350kyr of this core was constructed by correlating the dated series of relative paleointensity lows recognized in geomagnetic intensity records, marine isotope stage (MIS) boundaries determined in broad variations of the lithophysical and productivity proxies, and tephrochronology. The orbital changes of the lithophysical and productivity proxy stacks lag behind Northern Hemisphere summer radiation by approximately 6.3 and 5.9kyr, respectively. This lag is consistent with a Milankovich model of climate control by solar radiation through the northern ice sheet volume and sea surface and surrounding land responses, which are fast compared with sedimentological evidence. Productivity proxies of the Okhotsk Sea also demonstrate 52 abrupt, pronounced productivity minima associated with regional climate coolings during the last 350kyr, which present useful indicators of millennial-scale climate changes in this marginal sea. Based on the postulated synchronicity of Dansgaard–Oeschger cycles in the Northern Hemisphere and the established simultaneity of 11 Okhotsk Sea coolings in the last 77kyr with abrupt severe cold events in the Greenland ice core and North Atlantic Heinrich events, all of these may be regarded as Heinrich-equivalent event anomalies. The Okhotsk Sea events have their counterparts in the records of North Atlantic sediments, the Greenland ice sheet, East Asia summer monsoon, and the Antarctic ice sheet. Probably the Arctic Oscillation was the main factor determining orbital and millennial climate oscillations in the high-latitude Northern Hemisphere, including the Okhotsk Sea region.

Heat- and cold-related mortality in the North-East of Poland as an example of the socio-economic effects of extreme hydrometeorological events in the Polish Lowland

This article looks at certain socioeconomic consequences of extreme hydrometeorological phenomena in the Polish Lowland, e.g. floods, droughts, hurricanes, heat and cold waves that have all become more intense in Poland over recent years. The particular focus is on the impact of extreme high temperature and severe cold events on socio-medical parameters such as mortality. The analysis is especially concerned with increased daily numbers of deaths in 3 large urban centers located in northeast Poland.

Chronostratigraphie des accumulations würmiennes dans la moyenne vallée du Rhône. L'apport des dates radiocarbone

A radiocarbon dating of the Moras drilling (30 800 cal BP) is located at the bottom of lacustrine deposits on the Crémieu plateau. A former ice-dammed lake is attributed to the ponding of meltwaters in the Moras River valley by a diffluence of the Rhône glacier It allows to assert that the Rhône glacier did invade the piedmont of the Alps dunng the Late Würm and that this recurrence can be correlated with the so-called stade D (Mandier, 1988a). This stratigraphy is confirmed elsewhere in the fluvio-glacial alluvium of the Rhône valley m the Péage-de-Roussillon area (24 000 cal BP and 22 250 cal BP) and m the alluvium of the Isère valley at Saint-Hilaire-du-Rosier (32 500 cal BP and 25 500 cal BP). The last Würm terraces above the Holocene levels are positioned at two thirds of the amount of total incision following stade D. All of these terraces are comprised in between 17 000 cal BP and 18 250 cal BP in the Rhône and in the Isère valley. They are correlated with stade E (Morestel stade). A tentative correlation with Greenland GRIP drilling is proposed : the Rhône LGM of stade A > 45 000 cal BP (considering the presence of Mousterian industry on top of a terrace) is better correlated with isotopic stade 4 (Heinrich 6 event). For stades B and C, two solutions are proposed. The first one links these stades to the double cold event occurring between GRIP interstadial 4 and 5. The second one, correlates stades B and C with Heinrich 4 and Heinrich 5 events. Stade D can be clearly attributed to the severe cold event, which occurred between GRIP interstadial 3 and 2 (Heinrich 2 event). At last, stade E (Morestel) must be attnbuted to the cold event which follows interstadial 2 and which ends at 1 8 250 cal BP.