张家口市崇礼的雪季与冬奥会赛期的降雪特征分析

利用张家口市崇礼1960—2014年逐日降水和天气现象资料,分析了雪季与冬奥会赛期(2月4—20日)的降雪特征。结果显示:崇礼最早降雪初日为10月13日,最迟降雪终日为4月30日,初、终雪日多年平均为11月2日和4月6日;雪季长度最长和最短分别为190 d和123 d,多年平均为156 d。雪季间最长连续无降雪时段多出现在12月末到1月下旬。冬奥会赛期前的11月上旬降雪日数少,但降雪量较大;此后各旬降雪日数、雪量差异不大。2月4—20日间平均4~5 d出现一次降雪,且主要为中小雪,出现大雪的概率极低。这些结果为冬奥会赛场充分利用降雪资源、制定赛事计划和赛事期间的气象条件预测及预报等保障提供参考依据。

黔金丝猴(Rhinopithecus brelichi)雪季地表食物利用

2012年1月至3月,本研究采用粪便分析法对黔金丝猴冬季的食物利用进行了调查研究。结果表明在此期间黔金丝猴采食植物部位有嫩枝、树芽、叶片、花、树皮以及果实和种子,食物种类较多。其中,地表灌木层木姜子属(Litsea sp.)的嫩枝是黔金丝猴取食较多的采食对象。本次研究也首次发现黔金丝猴食用地面上的四照花果实。我们推测黔金丝猴利用落地果实的现象可能是该物种对温带森林中高质量食物果实和种子利用最大化的一种适应。建议在温带灵长类生态行为研究中,加强对落地果实、矮小灌木和草本植物等猴群食源植物的监测,以期精确地探讨物种的食性以及对环境的适应。

雪季

雪季老马都在期盼用绚烂编织花环，把风和日丽的景色装点；都在向往将芳香洒向绿野，把蜂飞蝶舞的世界渲染。春风尽了，秋雨歇了，你把深情留给了茫茫雪原，在不属于花的季节里，挺直了腰杆。也许，和煦的日子太平淡，你选择了严寒，因为严寒靠近春天；也许，岁月的尘埃太...

谁的雪季

北国。今冬无雪初冬的月。

雪季，与北京大栅栏的美丽邂逅

阳春三月．雪花被阳光感动的季节。窗外，皑皑白雪。望着春天里飘飘洒洒的落雪，让我想起了春节过后，途经北京时的那场雪。以及与大栅栏的美丽邂逅。

三十六个雪人

师专毕业后,我被分配到了全县最偏僻的一个山区。 学校的实际情况比我想像的还糟。整个中学就三个班,三个老师。

Seasonal Behavior of Pavement in Geothermal Snow-Melting System with Solar Energy Storage

A two-dimensional unsteady heat transfer model of pavement of geothermal road snow-melting system (GRSS) with solar energy storage is established and numerical simulation is carried out based on annual hourly meteorological data and boundary conditions. Simulated results show that ground surface temperature and heating flux decrease with the increase of buried depth, but increase with the increase of fluid temperature in winter. Heat-extracted amount and efficiency drop with the increase of fluid temperature in summer.Compared with ambient temperature, solar radiation has more direct influence on the heat-extracted flux of pipe walls of GRSS in summer. The relationships among maximum and idling snow-melting load, the rate of snowfall, ambient temperature and wind speed are made clear, which provides necessary references for the design and optimization of a practical road snow-melting system.

Warming over the North Pacific can intensify snow events in Northeast China

The variation of winter snowfall intensity over Northeast China and its relationship with the autumn North Pacific SST are investigated for the period 1960–2012. An upward trend is apparent for the winter snowfall intensity over Northeast China during the last half-century, coinciding with an increasing autumn SST over the North Pacific. Their interannual correlation coefficient reaches up to 0.58 for the past five decades, and 0.42 after their trends are removed. Further analyses indicate that the warming SST during autumn may persist into winter. Correspondingly, large parts of East Asia and the North Pacific are dominated by an anticyclonic anomaly, which can induce an anomalous southeasterly over Northeast China, weaken the northerly wind, then warm the surface, increase the water vapor content and intensify snowfall events. Thus, the autumn North Pacific SST can be considered as a key predictor for winter snowfall events over Northeast China. Results from leaveone-out cross-validation and independent validation both show a significant correlation and a small RMSE between prediction and observation. Therefore, the autumn SST over the North Pacific is suggested as a potential predictor for winter snowfall intensity in Northeast China.

Potential predictability of Eurasian spring snow water equivalent in IAP AGCM4 hindcasts

The potential predictability and skill of Eurasian spring snow water equivalent(SWE)are explored by using a suite of ensemble hindcast experiments with the fourth-generation IAP AGCM(IAP AGCM4)and observations for the period 1982–2012.IAP AGCM4 is generally capable of reproducing the spatial distribution of Eurasian spring SWE;nevertheless,the model overestimates the SWE over Eurasia,possibly because of positive precipitation biases in wintertime.IAP AGCM4 can successfully capture the long-term trend and leading pattern of Eurasian spring SWE.Additionally,the spring SWE anomalies are generally predictable in many regions over Eurasia,especially at high latitudes;moreover,IAP AGCM4 exhibits a remarkable prediction skill for spring SWE anomalies over Eurasia in many years during 1982 to 2012.In order to reveal the relative impacts of SST anomalies and atmospheric initial conditions on the seasonal predictability of Eurasian spring SWE,two additional sets of experiments are carried out.Overall,atmospheric initial anomalies have a dominant role,though the impact of SSTs is not negligible.This study highlights the importance of atmospheric initialization in seasonal climate forecasts of spring SWE anomalies,especially at high latitudes.

Possible connection between anomalous activity of Scandinavian Atmospheric Teleconnection Pattern and winter snowfall in the Yangtze-Huaihe River Basin of China

The temporal and spatial characteristics of winter snowfall in the Yangtze–Huaihe River Basin (YHRB) of China and its possible connection with Scandinavian Atmospheric Teleconnection Pattern (SCAND) anomalies are explored based on daily meteorological data contained in the Daily Surface Climate Dataset for China (V3.0) during the period 1960–2012. Results show that winter snowfall in the YHRB exhibits consistent anomalies over the whole region for the interannual variation during 1960–2012. Further analysis suggests that winter snowfall anomalies in the YHRB are closely linked to the anomalous wintertime SCAND activity. When there is more winter snowfall in the YHRB, SCAND is usually in a positive phase, accompanied by a strengthened Urals blocking high and East Asian trough, which is conducive to strengthened cold-air activity, intensified vertical motions, and more water vapor transport in the YHRB. In contrast, less winter snowfall in the YHRB usually happens in the negative phase of SCAND. Our results provide useful information to better understand the relevant mechanism responsible for anomalous winter snowfall in this area.

Effects of spring Arctic sea ice on summer drought in the middle and high latitudes of Asia

Based on data observed from 1979 to 2017,the influence of Arctic sea ice in the previous spring on the first mode of interannual variation in summer drought in the middle and high latitudes of Asia(MHA)is analyzed in this paper,and the possible associated physical mechanism is discussed.The results show that when there is more sea ice near the Svalbard Islands in spring while the sea ice in the Barents-Kara Sea decreases,the drought distribution in the MHA shows a north-south dipole pattern in late summer,and drought weakens in the northern MHA region and strengthens in the southern MHA region.By analyzing the main physical process affecting these changes,the change in sea ice in spring is found to lead to the Polar-Eurasian teleconnection pattern,resulting in more precipitation,thicker snow depths,higher temperatures,and higher soil moisture in the northern MHA region in spring and less precipitation,smaller snow depths,and lower soil moisture in the southern MHA region.Such soil conditions last until summer,affect summer precipitation and temperature conditions through soil moisture–atmosphere feedbacks,and ultimately modulate changes in summer drought in the MHA.

1961-2012年中国降雪时空变化特征分析

利用1961-2012年中国有固态降水观测且序列完整的1 400多站逐日降水量和天气现象数据,建立了完整性较好的降雪序列,选取雪季长度、降雪量、降雪日数、降雪强度和最大降雪量5个指标,分区域研究了中国降雪的时空变化特征。结果表明:中国降雪在空间上主要分布在青藏高原地区、东北地区以及新疆天山以北地区;中国大部分地区降雪量以小雪等级占主要,华中地区以暴雪等级的降雪量占主要;5个区域的降雪日数均以小雪等级占主要,华中地区占65%,其余区域占84%左右;5个区域的雪季长度均为缩短趋势,新疆北部地区主要由于雪季开始期大幅滞后,青藏高原地区、华北地区和华中地区主要由于雪季结束期大幅提前,东北和内蒙古东北部雪季缩短的原因中,雪季开始期滞后和雪季结束期提前各占一半;在降雪的时间变化上,新疆北部地区,降雪量和降雪日数为增加趋势,大雪等级降雪显著增加,东北和内蒙古东北部地区的降雪量和降雪日数无显著变化,其余3个区域的降雪量和降雪日数均有显著减少趋势,其中青藏高原地区暴雪和小雪等级的降雪量显著减少,华北地区的小雪等级降雪量减少显著,华中地区大雪和小雪等级降雪量减少显著。

Metamorphism and Microstructure of Seasonal Snow:Single Layer Tracking in Western Tianshan,China

【Title】【Author】Snowpack is a combination of several snow layers. Accordingly, snowpack natural metamorphism is composed of several stages. The aim of this study is to investigate the natural snow metamorphism at the snow layer unit. The field investigation was conducted at the Tianshan Station for Snow Cover and Avalanche Research, Chinese Academy of Sciences （43°16＇ N, 84°24＇ E, and 1,776 m a.s.l.）, during the winter of 2010-2011. A complete metamorphic procedure and the corresponding microstructure of a target snow layer were tracked. The results indicate that： the ideal and complete metamorphic process and the corresponding predominant snow grain shape have 5 stages： 1） unstable kinetic metamorphism near the surface; 2） unstable kinetic metamorphism under pressure; 3） stable kinetic metamorphism; 4） equilibrium metamorphism; 5） wet snow metamorphism. Snow grain size sharply decreased in the surface stage, and then changed to continuously increase. Rapid increase of grain size occurred in the stable kinetic metamorphism and wet snow metamorphism stage. The characteristic length was introduced to represent the real sizes of depth hoar crystals. The snow grain circularity ratio had a variation of “rapid increase – slow decrease – slow increase”, and the snow aggregations continuously increased with time. Snow density grew stepwise and remained steady from the stable kinetic to the equilibrium metamorphism stage. The differences in metamorphism extent and stages among snow layers, led to the characteristic layered structure of snowpack.

雨雪混合季，我把自己诗化了

昨天晚上，天酝酿了一整夜，参议的云越聚越多，压得星星熄灭了气息，不再给空中一点点可以目测的距离。

Energy Budget over Seasonal Snow Surface at an Open Site and Beneath Forest Canopy Openness during the Snowmelt Period in Western Tianshan Mountains,China

In this study, meteorological factors and snowmelt rate at an open site on sunny slope(OPS) and beneath forest canopy openness on shady slope(BFC) were measured using an automatic weather station and snow lysimeter during the snowmelt period in 2009, 2010 and 2013. The energy budget over snow surface was calculated according to these meteorological datasets. The analysis results indicated that the net shortwave radiation(K) and sensible heat flux(H) were energy sources, and the latent heat flux(LVE) was energy sinks of snow surfaces at all sites. The net longwave radiation(L) was energy sink at OPS and 80% BFC, but energy source at 20% BFC. The gain of K, H, and the loss of LVE at BFC were obviously lower than those at OPS. The L was the maximum difference of energy budget between snow surface at BFC and OPS. In warm and wet years, the most important factor of the energy budget variation at OPS was air humidity and the second mostimportant factor was air temperature. However, the ground surface temperature on the sunny slope was the most important factor for L and energy budget at BFC. With the increases in forest canopy openness and the slope of adjacent terrains, the influences of ground surface temperature on the sunny slope on L and the energy budget over snow surface at BFC increased, especially when the snow cover on the sunny slope melts completely.

Subseasonal prediction of winter precipitation in southern China using the early November snowpack over the Urals

Evolution of the autumn snowpack has been considered as a potential source for the subseasonal predictability of winter surface air temperature,but its linkage to precipitation variability has been less well discussed.This study shows that the snow water equivalent(SWE)over the Urals region in early(1–14)November is positively associated with precipitation in southern China during15–21 November and 6–15 January,based on the study period 1979/80–2016/17.In early November,a decreased Urals SWE warms the air locally via diabatic heating,indicative of significant land–atmosphere coupling over the Urals region.Meanwhile,a stationary Rossby wave train originates from the Urals and propagates along the polar-front jet stream.In mid(15–21)November,this Rossby wave train propagates downstream toward East Asia and,combined with the deepened East Asian trough,reduces the precipitation over southern China by lessening the water vapor transport.Thereafter,during 22 November to 5 January,there are barely any obvious circulation anomalies owing to the weak land–atmosphere coupling over the Urals.In early(6–15)January,the snowpack expands southward to the north of the Mediterranean Sea and cools the overlying atmosphere,suggestive of land–atmosphere coupling occurring over western Europe.A stationary Rossby wave train trapped in the subtropical westerly jet stream appears along with anomalous cyclonic circulation over Europe,and again with a deepened East Asian trough and less precipitation over southern China.The current findings have implications for winter precipitation prediction in southern China on the subseasonal timescale.

Northern-Hemisphere Snow Cover Patterns and Formation Conditions in Winter 2007 and 2012

The Arctic sea ice minimum records appeared in the Septembers of 2007 and 2012, followed by high snow cover areas in the Northern Hemisphere winters. The snow cover distributions show different spatial patterns in these two years: increased snow cover in Central Asia and Central North America in 2007, while increased snow cover in East Asia and northwestern Europe in 2012. The high snow cover anomaly shifted to higher latitudes in winter of 2012 compared to 2007. It is noticed that the snow cover had positive anomaly in 2007 and 2012 with the following conditions: the negative geopotential height and the related cyclonic wind anomaly were favorable for upwelling, and, with the above conditions, the low troposphere and surface air temperature anomaly and water vapor anomaly were favorable for the formation and maintenance of snowfalls. The negative geopotential height, cyclonic wind and low air temperature conditions were satisfied in different locations in 2007 and 2012, resulting in different spatial snow cover patterns. The cross section of lower air temperature move to higher latitudes in winter of 2012 compared to 2007.

Progress in Research on the Impacts of Global Climate Change on Winter Ski Tourism

The impacts of global climate change on ski tourism, which depends heavily on climate conditions, have increasingly gained concern overseas. This paper systematically summarized the relevant research ideas, the technical methods used, and the obtained achievements through an extensive synthesis of the previous studies. Moreover, the major shortcomings and the limitations in the recent studies are pointed in order to present a useful reference for our Chinese investigators. It indicates that the future climate warming would cause the loss of skiable areas, the shortening of skiing seasons and the sharp drop of ski visitors in many low altitude and low latitude ski resorts. The paper finally stressed that future research should pay particular attention to strengthening interdisciplinary cooperation and consider more factors about the impacts of climate-induced environmental changes on tourist flows. In the future ski resort planning and management, the possible impacts of global climate change should be taken into account.

The Influence of Seasonal Snow on Soil Thermal and Water Dynamics under Different Vegetation Covers in a Permafrost Region

Seasonal snow is one of the most important influences on the development and distribution of permafrost and the hydrothermal regime in surface soil. Alpine meadow, which constitutes the main land type in permafrost regions of the Qinghai-Tibet Plateau, was selected to study the influence of seasonal snow on the temperature and moisture in active soil layers under different vegetation coverage. Monitoring sites for soil moisture and temperature were constructed to observe the hydrothermal processes in active soil layers under different vegetation cover with seasonal snow cover variation for three years from 2010 to 2012. Differences in soil temperature and moisture in areas of diverse vegetation coverage with varying levels of snow cover were analyzed using active soil layer water and temperature indices. The results indicated that snow cover greatly influenced the hydrothermal dynamics of the active soil layer in alpine meadows. In the snow manipulation experiment with a snow depth greater than 15 cm, the snow cover postponed both the freeze-fall and thawrise onset times of soil temperature and moisture in alpine LC(lower vegetation coverage) meadows and of soil moisture in alpine HC(higher vegetation coverage) meadows; however, the opposite response occurred for soil temperatures of alpine HC meadows,where the entire melting period was extended by advancing the thaw-rise and delaying the freeze-fall onset time of the soil temperature. Snow cover resulted in a decreased amplitude and rate of variation in soil temperature, for both alpine HC meadows and alpine LC meadows, whereas the distinct influence of snow cover on the amplitude and rate of soil moisture variation occurred at different soil layers with different vegetation coverages. Snow cover increased the soil moisture of alpine grasslands during thawing periods. The results confirmed that the annual hydrothermal dynamics of active layers in permafrost were subject to the synergistic actions of both snow cover and vegetation coverage.

纵使霜雪下了一整季

一颗星即使再明亮，也终是孤单，假使可以相伴，我愿与你做两颗默默无闻的石头。