Subseasonal transition of Barents-Kara sea-ice anomalies in winter related to the reversed warm Arctic-cold Eurasia pattern

“暖北极-冷欧亚”模态(WACE)的次季节反转会触发中国东部冬季的极端冷/暖转换以及春季沙尘暴.在这一显著的高纬度大气模态反转的驱动下,巴伦支海-喀拉海(BKS)的海冰异常也表现出次季节转换.当北极变暖以及乌拉尔山高压增强时,BKS异常向下的湍流热通量和增强的向下红外辐射有利于海冰融化;近地面的异常偏南风使海冰从薄冰区向多年冰区漂移,进一步扩大了开阔洋面.相反的机制出现在WACE反位相,导致BKS海冰异常偏多.当WACE次季节反转时,上述机制分别发生在前冬和后冬,使得BKS海冰异常出现显著的次季节转换.近10年随着WACE反转频率增多,BKS海冰前后冬的次季节变化增强.本文构建了WACE次季节反转的综合示意图,有助于更好地理解和预测中国东部极端气候.

Construction Technology of Warm Mix Asphalt Pavement in Cold High-Altitude Areas

With the continuous development of domestic highway construction,highway civil engineering and service level quality have attracted much attention.Good pavement quality and high-quality service make people feel comfortable and smooth when traveling.High-quality pavement can significantly reduce the probability of traffic accidents.At present,there is a direct relationship between pavement quality and pavement construction operations.Carrying out pavement construction operations in cold high-altitude areas requires a reasonable selection of construction equipment and methods.The application of warm-mix asphalt pavement construction technology can ensure pavement quality.Therefore,this paper analyzes the advantages of warm-mix technology,the environmental characteristics of cold high-altitude areas,and construction preparations,and discusses the construction technology of warm-mix asphalt pavement in cold high-altitude areas in detail,to improve the overall road quality of cold high-altitude areas.

Effects of cold preservation and warm reperfusion on rat fatty liver

INTRODUCTIONAlthough liver transplantation for irreversible liverdiseases is increasingly prevalent worldwide,patientdie while waiting for donors because of organshortages.One important problem commonlyencountered is that fatty livers often affect theoutcome of liver transplantation.It is reported thatthe incidence of abnormal fatty livers in autopsiesafter accidental death ranged from 15% to 24%.Since fatty livers may result in a primarynonfunction (PNF)liver graft,which contributes

The 2020/21 Extremely Cold Winter in China Influenced by the Synergistic Effect of La Niña and Warm Arctic

In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La Niña event which exceeded both oceanic and atmospheric thresholds began in August 2020 and in a few months developed into its mature phase,just prior to the 2020/21 winter.In this report,the mid−high-latitude large-scale atmospheric circulation anomalies in the Northern Hemisphere,which were forced by the negative phase of Arctic Oscillation,a strengthened Siberian High,an intensified Ural High and a deepened East Asian Trough,are considered to be the direct reason for the frequent cold surges in winter 2020/21.At the same time,the synergistic effect of the warm Arctic and the cold tropical Pacific(La Niña)provided an indispensable background,at a hemispheric scale,to intensify the atmospheric circulation anomalies in middle-to-high latitudes.In the end,a most recent La Niña prediction is provided and the on-coming evolution of climate is discussed for the remaining part of the 2020/21 winter for the purpose of future decision-making and early warning.

Characteristics of Temperature Change in China over the Last 2000 years and Spatial Patterns of Dryness/Wetness during Cold and Warm Periods

This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation in China has exhibited significant 50–70-yr, 100–120-yr, and 200–250-yr cycles. Results also show that the amplitudes of decadal and centennial temperature variation were 1.3℃ and 0.7℃, respectively, with the latter significantly correlated with long-term changes in solar radiation, especially cold periods, which correspond approximately to sunspot minima. The most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56°± 0.42℃（100 yr）^（-1）; however, temperatures recorded in the 20 th century may not be unprecedented for the last 2000 years, as data show records for the periods AD 981–1100 and AD1201–70 are comparable to the present. The ensemble means of dryness/wetness spatial patterns in eastern China across all centennial warm periods illustrate a tripole pattern： dry south of 25°N, wet from 25°–30°N, and dry to the north of 30°N. However, for all centennial cold periods, this spatial pattern also exhibits a meridional distribution. The increase in precipitation over the monsoonal regions of China associated with the 20 th century warming can primarily be attributed to a mega El Nino–Southern Oscillation and the Atlantic Multidecadal Oscillation. In addition, a significant association between increasing numbers of locusts and dry/cold conditions is found in eastern China. Plague intensity also generally increases in concert with wetness in northern China, while more precipitation is likely to have a negative effect in southern China.

Effects of a Traditional Japanese Medicine Goshajinkigan, Tokishigyakukagoshuyushokyoto on the Warm and Cold Sense Threshold and Peripheral Blood Flow

The purpose of this study was to investigate the effects of a traditional Japanese medicine Goshajinkigan (TJ-107) and Tokishigyakukagoshuyushokyoto (TJ-38) on warm sense threshold, cold sense threshold and the peripheral blood flow. 31 healthy volunteers (control group: 9people, TJ-107 group: 12 people, TJ-38group:10 people) were examined. Drugs administered 2.5 g a dose. Analysis was before and after 1 hour dosage. The warm and cold sense threshold in the thenar of the non-handedness site of these subjects was measured using a thermostimulator (Intercross-200, Intercross Co., Tokyo, Japan). The peripheral blood flow in the finger of the non-handedness site of these subjects was measured using a full-field laser perfusion imager (FLPI, Moor Instruments Ltd., England). Control: The vehicle had no significant effect on the warm sense threshold, cold sense threshold and the peripheral blood flow. TJ-107: The warm sense threshold and cold sense threshold were significantly decreased, and the reaction latency of cold sense was significantly shortening. The peripheral blood flow was significantly increased second and third finger at 115.6%, 119.3%, respectively. TJ-38: The cold sense threshold and the reaction latency of cold sense were significantly increased. The peripheral blood flow was significantly increased second and third finger with 114.3%, 112.8%, respectively. These results suggest that TJ-107 and TJ-38 have effects on the changed warm sense threshold, cold sense threshold and increased peripheral blood flow.

THE FREQUENCY CHARACTERISTICS OF WARM AND COLD EPISODES IN THE NIO REGIONS

On the basis of NOAA/CPC data of sea surface temperature anomaly in the Nio regions during Jan. 1950 – Dec. 2003, the wavelet power spectrum of SST were studied with significance and confidence testing at different scales in this paper. It shows that the SST are provided with multi-time scales structure nested one another, and vary on scales of 2 – 7 years, 8 – 20 years and >30 years. The most significant variation of the warm and cold episodes is in the 4-year band of period. The power, frequency structure and confidence of the same episode are different in different Nio regions. The intensity of oscillations is increasing at low frequency bands and decreasing at high frequency bands from east to west in the Ni?o regions, especially after 1970.

Opposing Trends of Winter Cold Extremes over Eastern Eurasia and North America under Recent Arctic Warming

Under recent Arctic warming,boreal winters have witnessed severe cold surges over both Eurasia and North America,bringing about serious social and economic impacts.Here,we investigated the changes in daily surface air temperature(SAT)variability during the rapid Arctic warming period of 1988/89–2015/16,and found the daily SAT variance,mainly contributed by the sub-seasonal component,shows an increasing and decreasing trend over eastern Eurasia and North America,respectively.Increasing cold extremes(defined as days with daily SAT anomalies below 1.5 standard deviations)dominated the increase of the daily SAT variability over eastern Eurasia,while decreasing cold extremes dominated the decrease of the daily SAT variability over North America.The circulation regime of cold extremes over eastern Eurasia(North America)is characterized by an enhanced high-pressure ridge over the Urals(Alaska)and surface Siberian(Canadian)high.The data analyses and model simulations show the recent strengthening of the high-pressure ridge over the Urals was associated with warming of the Barents–Kara seas in the Arctic region,while the high-pressure ridge over Alaska was influenced by the offset effect of Arctic warming over the East Siberian–Chukchi seas and the Pacific decadal oscillation(PDO)–like sea surface temperature(SST)anomalies over the North Pacific.The transition of the PDO-like SST anomalies from a positive to negative phase cancelled the impact of Arctic warming,reduced the occurrence of extreme cold days,and possibly resulted in the decreasing trend of daily SAT variability in North America.The multi-ensemble simulations of climate models confirmed the regional Arctic warming as the driver of the increasing SAT variance over eastern Eurasia and North America and the overwhelming effect of SST forcing on the decreasing SAT variance over North America.Therefore,the regional response of winter cold extremes at midlatitudes to the Arctic warming could be different due to the distinct impact of decadal SST anomalies.

Onshore warm tongue and offshore cold tongue in the western Yellow Sea in winter:the evidence

A winter onshore warm tongue extending from the Yellow Sea Warm Current to the southern Jiangsu coast, and an of fshore cold tongue extending from the southern Jiangsu coast to the southwest of Jeju Island(South Korea), are newly identified based on the sea-surface temperature from satellite remote sensing, and further confirmed by the distribution of suspended sediments. In addition, there are two obvious thermal fronts associated with the onshore warm tongue and off shore cold tongue. The narrow gap between the two thermal fronts is supposed to be the pathway for the off shore transport of cold coastal water and suspended sediments. The concurrence of onshore warm and of fshore cold tongues suggests the concurrence of onshore and off shore currents in the western Yellow Sea in winter, which seems to be inconsistent with the previously accepted view that, in winter, the Yellow Sea Coastal Current flows from the Old Huanghe Delta to the southwest of Jeju Island. This distinctive phenomenon helps establish an updated view of the circulation in the western Yellow Sea in winter.

Comparative Analysis of Strong Convection Process of Convective Cold Cloud and Convective Warm Cloud Type

On the night of April 20, 2017, there was a heavy rain in Longyan City, accompanied by strong convective weather such as strong lightning, short-term heavy precipitation, and 6 - 8 thunderstorms. The three-hour rain intensity and the six-hour rain intensity of Shanghang Tongxian Township and Nanyang Town were once in a century. Through the use of radar, radar wind profile and lightning locator data, the process can be divided into two phases: The first stage is the strong precipitation stage of Changting Datong Town during the 20 - 22 periods on the 20th. The process is accompanied by short-term heavy precipitation (59.7 mm/h), strong lightning activity, and 6 - 8 thunderstorm gales. It is a convective cold cloud dominated precipitation. The second stage is the strong precipitation stage of Shanghang Tongxian Township on the 21st, 02 - 04, and the short-term strong precipitation intensity reaches 75.7 mm/h, but the lightning and wind activity are weak, which is the convective warm cloud-oriented precipitation. There are significant differences in the strong convective weather between the two phases in the same background. The analysis shows that the strong echo of the first stage radar (above 60 dBz) is block-shaped southward, the speed of movement is fast, the height of the echo top is high, and the rear nascent monomer forms a train effect. In the second stage, the southwest-northeast-oriented convective zone moves to the northeast direction, forming the train effect of the echo zone. The center intensity is above 50 dBz, the echo top height is low, and the precipitation center moves slowly. This caused a large amount of accumulated rainfall. In this paper, the radar data is used to analyze the heavy rainfall process on the west coast of the straits, which has certain indication significance for the predictability of strong convective weather.

Assessment of Warm and Cold Ischemia on Functions of the Operated Kidney with ^99mTc-DMSA in Renal Masses: A Prospective and Randomized Study

Objective: To examine the effect of warm and cold ischemia on functions of the operated kidney in cases with a normal contralateral kidney undergoing nephron sparing surgery. Methods: This study enrolled 40 patients with a normal contralateral kidney and without a renal function threatening risk factor, who were operated with NSS. The patients were randomized at admission. They were divided into 2 equal groups as warm and cold ischemia. An ice application for 10 minutes was done to cold ischemia group after clamping renal artery. Renal functions were evaluated with Technesium-99m-Dimercaptosuccinic Acid (DMSA) and serum creatinine at the preoperative and postoperative (day 1, day 15, month 6, and month 12) period. Statistical analysis was done with Mann Whitney U test, Wilcoxon Signed Rank test, and Fredman test. A p value below 0.05 was considered statistically significant. Results: There were no significant differences between the groups in terms of age, body mass index, ischemia time, tumor size, amount of hemorrhage, and procedure time. Both groups had a significantly higher DMSA uptake at the preoperative period compared with the postoperative period (postoperative day 1, day 15, month 6, and month 12) (p 0.001). However, both groups had similar DMSA uptake results at the postoperative period. Preoperative and postoperative creatinine levels were not significantly different from each other in both groups. Conclusion: Based on tumor localization, nephron sparing surgery without use of superficial cooling appears as a viable option for small renal masses.

Extremely Cold and Warm Days in the Spanish Central Plateau: Analysis of Its Evolution from 1961 to 2010

From anomalies of daily data of maximum and minimum temperatures, that have been obtained as difference between the real data of every day and the average data of the corresponding day of the year in each of the 14 observatories of the Spanish Central Plateau (8 in North subplateau and 6 in the South subplateau) between 1961-2010, the extremely cold and warm days are determined, throughout all the year, in all the study area and the two different sub areas. We consider a day as an extremely cold day (ECD) if achieves simultaneously the following conditions: the anomaly of minimum temperature of the day is lower than the value of the P05 percentile of the series of daily anomalies of minimum temperature, and the value of the anomaly of daily maximum temperature is lower, as well, than the P05 percentile of the corresponding series of anomalies. The values of the thresholds determined by these percentiles are obtained considering the complete anomalies daily series of temperature for all the study regions. In order to establish the extremely warm days the methodology is the same but the conditions are: the anomaly of minimum temperature of the day is greater than the value of the P95 percentile of the series of daily anomalies of minimum temperature, and the value of the anomaly of daily maximum temperature is greater as well than the P95 percentile of the corresponding anomalies series. Once the extremely warm and cold days are determined, throughout the year in the period of time considered, for each zone, the corresponding series of annual frequencies are obtained. The analysis of tendency of these series indicates that in all the cases the tendency of the frequency of the extremely cold days is decreasing. Considering a linear model for the temporary behavior of the frequency, the reduce is of the order of 1 day every 10 years. In the case of the extremely warm days its annual frequency presents an increasing tendency, which indicates that the number of extremely warm days per year has been increased during the studied time interval. In agreement with the linear model of behavior, the increase is, approximately, of the order of 1 day per decade.

Influence of Major Stratospheric Sudden Warming on the Unprecedented Cold Wave in East Asia in January 2021

An unprecedented cold wave intruded into East Asia in early January 2021 and led to record-breaking or historical extreme low temperatures over vast regions.This study shows that a major stratospheric sudden warming(SSW)event at the beginning of January 2021 exerted an important influence on this cold wave.The major SSW event occurred on 2 January 2021 and subsequently led to the displacement of the stratospheric polar vortex to the East Asian side.Moreover,the SSW event induced the stratospheric warming signal to propagate downward to the mid-to-lower troposphere,which not only enhanced the blocking in the Urals-Siberia region and the negative phase of the Arctic Oscillation,but also shifted the tropospheric polar vortex off the pole.The displaced tropospheric polar vortex,Ural blocking,and another downstream blocking ridge over western North America formed a distinct inverted omega-shaped circulation pattern(IOCP)in the East Asia-North Pacific sector.This IOCP was the most direct and impactful atmospheric pattern causing the cold wave in East Asia.The IOCP triggered a meridional cell with an upward branch in East Asia and a downward branch in Siberia.The meridional cell intensified the Siberian high and low-level northerly winds,which also favored the invasion of the cold wave into East Asia.Hence,the SSW event and tropospheric circulations such as the IOCP,negative phase of Arctic Oscillation,Ural blocking,enhanced Siberian high,and eastward propagation of Rossby wave eventually induced the outbreak of an unprecedented cold wave in East Asia in early January 2021.

An Experimental Investigation on Low Load Combustion Stability and Cold-Firing Capacity of a Gasoline Compression Ignition Engine

Gasoline compression ignition (GCI) is one of the most promising combustion concepts to maintain low pollutant emissions and high efficiency. However, low load combustion stability and firing in cold-start operations are two major challenges for GCI combustion. Strategies including negative valve overlap (NVO), advanced injection strategies, fuel reforming, and intake preheating have been proposed in order to solve these difficulties;however, the cold start is still an obstacle. The objective of this work is to study effective methods to achieve GCI engine cold start-up. This work combines NVO, in-cylinder fuel reforming, and intake preheating to achieve quick firing under cold-start conditions and the subsequent warmup conditions. The results show that start of injection (SOI) during the intake stroke yields the best fuel economy, and injection during the compression stroke has the potential to extend the low load limit. Furthermore, SOI during the NVO period grants the ability to operate under engine conditions with cold intake air and coolant. With highly reactive products made by in-cylinder fuel reforming and fast heat accumulation in the combustion chamber, the NVO injection strategy is highly appropriate for GCI firing. An additional assisted technical method, such as intake preheating, is required to ignite the first firing cycle for a cold-start process. With the combination of NVO, in-cylinder fuel reforming, and intake preheating, the GCI engine successfully started within five combustion cycles in the experiment. After the firing process, the engine could stably operate without further intake preheating;thus, this method is appropriate for engine cold-start and warm-up.

Cold ischemia time in liver transplantation:An overview

The standard approach to organ preservation in liver transplantation is by static cold storage and the time between the cross-clamping of a graft in a donor and its reperfusion in the recipient is defined as cold ischemia time(CIT).This simple definition reveals a multifactorial time frame that depends on donor hepatectomy time,transit time,and recipient surgery time,and is one of the most important donor-related risk factors which may influence the graft and recipient’s survival.Recently,the growing demand for the use of marginal liver grafts has prompted scientific exploration to analyze ischemia time factors and develop different organ preservation strategies.This review details the CIT definition and analyzes its different factors.It also explores the most recent strategies developed to implement each timestamp of CIT and to protect the graft from ischemic injury.

Arctic warming and its influence on East Asian winter cold events:a brief recap

The rate of warming of Arctic surface temperature is about 2–3 times faster than the global mean surface warming. Increases of ice albedo feedback and water vapor as well as moisture intrusion from outside the Arctic all have major roles in this phenomenon. In contrast to this rapid Arctic warming, in recent decades, stronger cold air outbreaks have occurred more frequently during winter in East Asia than were recorded in the 1990s, resulting in severe socioeconomic impacts. A number of related studies have claimed the increased frequency of these stronger cold air outbreaks is linked to the amplified warming in the Arctic through complicated mechanisms. As there are time lags between the observed Arctic warming and East Asian cold weather response at various scales, understanding the entire chain of processes from the Arctic to East Asia has importance for forecasting winter weather in East Asia. There are two pathways linking Arctic warming with East Asian cold weather events. One is the synoptic-scale pathway in the lower troposphere via strengthening of the Siberian High initiated by Ural blocking. The other is the planetary-scale path through the stratosphere via activation of planetary waves and downward propagation, which weakens the polar vortex. This study briefly reviews the current understanding of the linkage mechanisms between Arctic warming and East Asian winter cold weather.

Donor hepatectomy time and liver transplantation outcomes: An opportunity that cannot be dismissed

The probability of developing primary dysfunction(PD)is a function of the probability of ischemia/reperfusion(I/R)injury.The probability of I/R injury in turn,is a function of several donor and transplantation process variables,among which is ischemia time.Custodio et al studied the duration of a special type of warm ischemia and showed,contrary to what is known,that a longer duration is not statistically different from a shorter one in PD development.This finding opens the door to the unforeseen opportunity of training fellows in performing hepatectomies,since the duration will not jeopardize liver transplant outcomes,albeit with some precautions.

Analysis of Changes of Extreme Temperature during June to August Season over Tanzania

Natural and human systems are exposed and vulnerable to climate extremes, which contributes to the repercussions of climate variability and the probability of disasters. The impacts of both natural and human-caused climate variability are reflected in the reported changes in climate extremes. Particularly at the local community levels in the majority of the regions, there is currently a dearth of information regarding the distribution, dynamics, and trends of excessive temperatures among the majority of Tanzanians. Over the years 1982-2022, this study examined trends in Tanzania’s extreme temperature over the June to August season. Based on the distinction between absolute and percentile extreme temperatures, a total of eight ETCCDI climate indices were chosen. Mann-Kendall test was used to assess the presence of trends in extreme climatic indices and the Sen’s Slope was applied to compute the extent of the trends in temperature extremes. The study showed that in most regions, there is significant increase of warm days and nights while the significant decrease of cold days and nights was evident to most areas. Moreover, nighttime warming surpasses daytime warming in the study area. The study suggests that anthropogenic influences may contribute to the warming trend observed in extreme daily minimum and maximum temperatures globally, with Tanzania potentially affected, as indicated in the current research. The overall results of this study reflect patterns observed in various regions worldwide, where warm days and nights are on the rise while cold days and nights are diminishing.

Abrupt temperature change and a warming hiatus from 1951 to 2014 in Inner Mongolia, China

An abrupt temperature change and a warming hiatus have strongly influenced the global climate.This study focused on these changes in Inner Mongolia, China. This study used the central clustering method, Mann-Kendall mutation test and other methods to explore the abrupt temperature change and warming hiatus in three different temperature zones of the study region based on average annual data series.Among the temperature metrics investigated, average minimum temperature(Tnav) shifted the earliest,followed by average temperature(Tnv) and average maximum temperature(Txav). The latest change was observed in summer(1990 s), whereas the earliest was observed in winter(1970 s). Before and after the abrupt temperature change, Tnav fluctuated considerably, whereas there was only a slight change in Txav.Before and after the abrupt temperature change, the winter temperature changed more dramatically than the summer temperature. Before the abrupt temperature change, Tnav in the central region(0.322°C/10 a)and west region(0.48°C/10 a) contributed the most to the increasing temperatures. After the abrupt temperature change, Tnav in winter in the central region(0.519°C/10 a) and in autumn in the west region(0.729°C/10 a) contributed the most to the temperature increases. Overall, in the years in which temperature shifts occurred early, a warming hiatus also appeared early. The three temperature metrics in spring(1991)in the east region were the first to exhibit a warming hiatus. In the east region, Txav displayed the lowest rate of increase(0.412°C/a) in the period after the abrupt temperature change and before the warming hiatus,and the highest rate of increase after the warming hiatus.