We collected and verified documentary records of the latest spring snowing dates(LSSD)in Hangzhou during Southern Song Dynasty.Furtherly,the statistical correlation between this proxy and February–April mean temperat...We collected and verified documentary records of the latest spring snowing dates(LSSD)in Hangzhou during Southern Song Dynasty.Furtherly,the statistical correlation between this proxy and February–April mean temperature in Hangzhou was examined,and samples later than the perennial mean of the LSSD during Southern Song Dynasty were transformed into the decadal mean of LSSD by means of Boltzmann function.General characteristics of this reconstructed LSSD series with a 10-year temporal resolution was analyzed,and it was also compared with other documentary evidences and reconstructed climate series in China for the period 1131–1270.The results and discussion suggested that:(1)Records of the LSSD in Hangzhou during Southern Song Dynasty did not refer to ice pellets and graupels,which had an explicit climate significance(–0.34℃/10 d,R2=0.37,p<0.001).However,when this proxy is used to reconstruct temperature changes,all dates should be converted into proleptic Gregorian style and meet the same criterion of"true Qi"as the Chinese traditional calendar after 1929.(2)The decadal mean of LSSD can be effectively estimated by using the forefront of LSSD in the decade on the basis of Boltzmann function,whose extrapolation has a lesser uncertainty than those on the basis of linear models or polynomial models.(3)The spring climate in Hangzhou during 1131–1270 was almost as warm as the period 1951–1980.At the centennial scale,this period can be divided into two phases:the cold 1131–1170 and the warm 1171–1270.In the latter,1181–1200 and 1221–1240 were two cold intervals at the multi-decadal scale.(4)The reconstructed LSSD series was consistent well with other documentary evidences and reconstructed climate series in China for 1131–1270,which may reflect the influence on the climate over most regions of China imposed by the Pacific Decadal Oscillation(PDO).展开更多
SINCE December 2025,Urumqi City and Altay Prefecture in northwest China’s Xinjiang Uygur Autonomous Region,and northeast China’s Jilin Province have both entered their snow seasons.The snow holidays(for primary and ...SINCE December 2025,Urumqi City and Altay Prefecture in northwest China’s Xinjiang Uygur Autonomous Region,and northeast China’s Jilin Province have both entered their snow seasons.The snow holidays(for primary and secondary school students)in Urumqi and Altay ran from December 1 to 5.When combined with the preceding and following weekends,the holiday extended to nine days.展开更多
Yiwu merchants ride a winter sports boom as“Made in China”winter gear heats up the global economy.YIWU,located in east China’s Zhejiang Province,is globally renowned as a hub for small commodities.This winter,its s...Yiwu merchants ride a winter sports boom as“Made in China”winter gear heats up the global economy.YIWU,located in east China’s Zhejiang Province,is globally renowned as a hub for small commodities.This winter,its snow and ice sports products are generating a surge in business.Products such as snowboards,ski goggles,and ski poles are drawing an increasing number of merchants worldwide for purchases.展开更多
Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of sno...Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of snow drought on the regional hydrology remain insufficiently understood.In this study,we integrated multisource data,including the Fifth Generation European Centre for Medium-Range Weather Forecasts Atmospheric Reanalysis for Land Applications(ERA5-Land)data and hydrological station data,to systematically assess the snow drought patterns and their impacts on streamflow during 1950–2023.We identified snow drought events based on precipitation and snow fraction anomalies relative to climatological means and classified them into warm snow drought,dry snow drought,and warm&dry snow drought.The results revealed that snow drought was a recurrent phenomenon,occurring in 51.70%of the years during the study period,with warm&dry snow drought accounting for 21.90%of the total events.Both the frequency and severity exhibited pronounced spatial variability,largely governed by the elevation and snowfall fraction.Specifically,the frequency of warm snow drought was negatively correlated with the snowfall fraction,decreasing on average by 0.20 per unit increase in snowfall fraction,whereas the frequency of dry snow drought was positively correlated,increasing by 0.07 per unit increase.The streamflow analysis results demonstrated that snow drought typically reduced the warm-season discharge by 5.00%–18.00%in certain rivers,thereby exacerbating the water stress during the dry season.The results of this study advance our understanding by explicitly linking the types of snow drought to hydrological responses in Central Asia’s high mountains,providing a scientific basis for climate adaptation and sustainable water resource management in Tajikistan.展开更多
China’s winter sports boom creates jobs and spurs economic growth,bringing substantial benefit to the general public,local governments,and businesses.CHINA’s ice and snow economy,riding on the winter sports boom,is ...China’s winter sports boom creates jobs and spurs economic growth,bringing substantial benefit to the general public,local governments,and businesses.CHINA’s ice and snow economy,riding on the winter sports boom,is stimulating consumption across the country,fueling regional development and creating new industrial ecosystems.This trend perfectly matches one of China’s key tasks for 2026.展开更多
How is a nation’s embrace of snow and ice shaping a new cultural identity and igniting a multi-trillion-yuan economic boom?ADRIAAN Smit now cannot imagine a life without snowboarding,a passion that has become central...How is a nation’s embrace of snow and ice shaping a new cultural identity and igniting a multi-trillion-yuan economic boom?ADRIAAN Smit now cannot imagine a life without snowboarding,a passion that has become central to his world.He is excited to witness how winter sports are fostering a new winter culture in China.Listening to Smit speaking so enthusiastically about the slopes,one might assume he was raised in a region where snow sports are a way of life,but the fact is quite the contrary.展开更多
Yiwu merchants ride a winter sports boom as“Made in China”gear heats up the global economy Yiwu,located in east China’s Zhejiang Province,is globally renowned as a hub for small commodities.This winter,its snow and...Yiwu merchants ride a winter sports boom as“Made in China”gear heats up the global economy Yiwu,located in east China’s Zhejiang Province,is globally renowned as a hub for small commodities.This winter,its snow and ice sports products are generating a surge in business.展开更多
As the wheel of time turns toward the year's end and the beginning of the new year,the snow-kissed land of Xizang gracefully unveils its grandeur and offers a feast of wonders for all to explore.Here,crystalline i...As the wheel of time turns toward the year's end and the beginning of the new year,the snow-kissed land of Xizang gracefully unveils its grandeur and offers a feast of wonders for all to explore.Here,crystalline ice and snow form a celestial winter realm.Amid the biting seasonal winds,o month-long New Year celebration brings one o deep,heartfelt warmth.Rarely witnessed elsewhere in the world,this collection of New Year customs stands as both a cultural marvel and a warm gift that the plateau bestows upon the depths of winter.展开更多
PHOTO NEWS Unforgettable Winter Break Tourists take selfies in front of snow sculptures in the Fenghuang Mountain Scenic Area,Yakeshi City in Inner Mongolia Autonomous Region,on December 7,2025.
China’s winter sports boom is expanding beyond its traditional northern heartlands,fueling a dynamic ice-snow economy and culture nationwide.This seasonal surge is driven by sustained investment and innovative develo...China’s winter sports boom is expanding beyond its traditional northern heartlands,fueling a dynamic ice-snow economy and culture nationwide.This seasonal surge is driven by sustained investment and innovative development models that are turning cold climates into hot economic opportunities.展开更多
Conversation A(in the coffee shop)Zach:What are you doing,Emily?I'm planning an event.I'm calling it“Neighborhood Snow Party!”Emily:Zach:Fun!When is it?It's this Saturday,January 31st.What's the time...Conversation A(in the coffee shop)Zach:What are you doing,Emily?I'm planning an event.I'm calling it“Neighborhood Snow Party!”Emily:Zach:Fun!When is it?It's this Saturday,January 31st.What's the time and place?It's from 10 a.m.to 4 p.m.at Emily:Zach:Emily:Green Hill Park.Zach:I can go!展开更多
Due to the high elevation and cold climate of the Tibetan Plateau,the western region retains extensive snow cover during the summer,which can exhibit rapid variability over the course of just a few days.This study uti...Due to the high elevation and cold climate of the Tibetan Plateau,the western region retains extensive snow cover during the summer,which can exhibit rapid variability over the course of just a few days.This study utilizes numerical experiments to investigate the atmospheric response to extreme Tibetan Plateau snow cover(TPSC)events on a subseasonal timescale during summer.The results indicate that the subseasonal variations in TPSC exert limited impact on nonlocal atmospheric circulation and temperature during this period.Nevertheless,local surface energy and atmospheric temperature exhibit rapid cooling responses to increased snow cover.Specifically,an increase in snow cover over the western Tibetan Plateau leads to a sharp rise in surface albedo,resulting in a reduction in land surface energy and a negative response in the diabatic heating rate from the surface to 350 hPa locally.This negative diabatic heating response subsequently causes a decline in both surface and overlying atmospheric temperatures.The temperature response is confined to the western Tibetan Plateau and extends vertically from the surface to approximately 350 hPa.These extreme TPSC events and their associated atmospheric impacts occur within a two-week timescale.展开更多
This study proposes a framework for the concept of“new quality productive forces”in the ice and snow economy(ISE)as a strategic response to global climate change and the demands of technological and industrial trans...This study proposes a framework for the concept of“new quality productive forces”in the ice and snow economy(ISE)as a strategic response to global climate change and the demands of technological and industrial transformation for high-quality development.These new quality productive forces in the ISE have developed alongside the zonal distribution of natural resources,strictly adhere to ecological principles,and integrate value transformation mechanisms specific to ice and snow resources.Their development is projected to generate multiple benefits across ecological,economic,and social dimensions.The new quality productive forces in the ISE are characterized by technology-driven resource development,synergistic integration across the entire ice and snow industry value chain,and a focus on high-quality,green growth.Grounded in geography and economics,the new quality productive forces in the ISE link scientific innovation,the reallocation of productive factors,and industrial upgrading within the context of resource constraints.Furthermore,they expand the growth potential of the ISE by fostering new production relations through digital,intelligent,and green integration,while advancing low-carbon,sustainable development under the guiding principle that“ice and snow landscapes are also mountains of gold and silver.”For China's ISE,these new quality productive forces emphasize rigorous resource protection,balanced human-environment relationships,a resilient integrated supply chain framework,and an efficient“dual circulation”economic model.Practical strategies include integrating production factors,optimizing spatial resource allocation,fostering industrial synergy,and adapting production relations,all aimed at advancing the sustainable and high-quality development of China's ISE.展开更多
This is an in-depth journey to experience the ice and snow of Changbai Mountain.In these few days,you will explore Changbai Mountain and enjoy powder skiing;gallop on the ski trail;watch the stunning wonders of snow r...This is an in-depth journey to experience the ice and snow of Changbai Mountain.In these few days,you will explore Changbai Mountain and enjoy powder skiing;gallop on the ski trail;watch the stunning wonders of snow rime on thousands of trees;conquer the ice and snow wilderness on a snowmobile and start an in depth magical mystery tour in lilin Province.展开更多
"The fairyland of ice and snow","the Garden of Eden in the depth of snow mountains","mythical wonderland in eastern Nyainqentanglha",or"a family of snow peaks"...Are those phras..."The fairyland of ice and snow","the Garden of Eden in the depth of snow mountains","mythical wonderland in eastern Nyainqentanglha",or"a family of snow peaks"...Are those phrases often used by netizens enough to describe Sapu Mountain?展开更多
The snow density is a fundamental variable of the snow physical evolution processes,which can reflect the snowpack condition due to the thermal and gravitational compaction.Snow density is a bridge to transfer snow de...The snow density is a fundamental variable of the snow physical evolution processes,which can reflect the snowpack condition due to the thermal and gravitational compaction.Snow density is a bridge to transfer snow depth to snow water equivalent(SWE)for the snow water resources research.Therefore,it is important to understand the spatiotemporal distribution of snow density for the appropriate estimation of SWE.In this study,in situ snow densities from more than 6,000 stations in the Northern Hemisphere were used to analyze the spatial and temporal variations in snow density.The results displayed that snow density varied spatially and temporally in the Northern Hemisphere,with range of below 0.1 to over 0.4 g/cm^(3).The average snow densities in the mountainous regions of western North America,southeastern Canada,and Europe range from approximately 0.24 to 0.26 g/cm^(3),which is significantly greater than the values of 0.16–0.17 g/cm^(3)observed in Siberia,central Canada,the Great Plains of the United States,and China.The seasonal growth rates also present large spatial heterogeneity.The rates are over 0.024 g/cm^(3)per month in Southeastern Canada,the west mountain of North America and Europe,approximately 0.017 g/cm^(3)per month in Siberia,much larger than approximately 0.004 g/cm^(3)per month in other regions.Snow cover duration is a critical factor to determine the snow density.This study endorses the small snow density in China based on meteorological station observations,which results from that the meteorological stations are dominantly distributed in plain areas with relative short snow cover duration and shallow snow.展开更多
Snow cover plays a critical role in global climate regulation and hydrological processes.Accurate monitoring is essential for understanding snow distribution patterns,managing water resources,and assessing the impacts...Snow cover plays a critical role in global climate regulation and hydrological processes.Accurate monitoring is essential for understanding snow distribution patterns,managing water resources,and assessing the impacts of climate change.Remote sensing has become a vital tool for snow monitoring,with the widely used Moderate-resolution Imaging Spectroradiometer(MODIS)snow products from the Terra and Aqua satellites.However,cloud cover often interferes with snow detection,making cloud removal techniques crucial for reliable snow product generation.This study evaluated the accuracy of four MODIS snow cover datasets generated through different cloud removal algorithms.Using real-time field camera observations from four stations in the Tianshan Mountains,China,this study assessed the performance of these datasets during three distinct snow periods:the snow accumulation period(September-November),snowmelt period(March-June),and stable snow period(December-February in the following year).The findings showed that cloud-free snow products generated using the Hidden Markov Random Field(HMRF)algorithm consistently outperformed the others,particularly under cloud cover,while cloud-free snow products using near-day synthesis and the spatiotemporal adaptive fusion method with error correction(STAR)demonstrated varying performance depending on terrain complexity and cloud conditions.This study highlighted the importance of considering terrain features,land cover types,and snow dynamics when selecting cloud removal methods,particularly in areas with rapid snow accumulation and melting.The results suggested that future research should focus on improving cloud removal algorithms through the integration of machine learning,multi-source data fusion,and advanced remote sensing technologies.By expanding validation efforts and refining cloud removal strategies,more accurate and reliable snow products can be developed,contributing to enhanced snow monitoring and better management of water resources in alpine and arid areas.展开更多
In winter,the weather is usually cold and everything seems a bit dull.Butthe sun in winter is special.When the sun shines brightly in the clear blue sky,it brings warm(1)to thecold world.The golden sunlight spreads he...In winter,the weather is usually cold and everything seems a bit dull.Butthe sun in winter is special.When the sun shines brightly in the clear blue sky,it brings warm(1)to thecold world.The golden sunlight spreads here and there and it makes the whitesnow shine like diamonds.Although the trees are usually bare in winter,but(2)they look beautiful with the sunlight falling on them.展开更多
基金National Key R&D Program of China,No.2017YFA0603300Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA19040101。
文摘We collected and verified documentary records of the latest spring snowing dates(LSSD)in Hangzhou during Southern Song Dynasty.Furtherly,the statistical correlation between this proxy and February–April mean temperature in Hangzhou was examined,and samples later than the perennial mean of the LSSD during Southern Song Dynasty were transformed into the decadal mean of LSSD by means of Boltzmann function.General characteristics of this reconstructed LSSD series with a 10-year temporal resolution was analyzed,and it was also compared with other documentary evidences and reconstructed climate series in China for the period 1131–1270.The results and discussion suggested that:(1)Records of the LSSD in Hangzhou during Southern Song Dynasty did not refer to ice pellets and graupels,which had an explicit climate significance(–0.34℃/10 d,R2=0.37,p<0.001).However,when this proxy is used to reconstruct temperature changes,all dates should be converted into proleptic Gregorian style and meet the same criterion of"true Qi"as the Chinese traditional calendar after 1929.(2)The decadal mean of LSSD can be effectively estimated by using the forefront of LSSD in the decade on the basis of Boltzmann function,whose extrapolation has a lesser uncertainty than those on the basis of linear models or polynomial models.(3)The spring climate in Hangzhou during 1131–1270 was almost as warm as the period 1951–1980.At the centennial scale,this period can be divided into two phases:the cold 1131–1170 and the warm 1171–1270.In the latter,1181–1200 and 1221–1240 were two cold intervals at the multi-decadal scale.(4)The reconstructed LSSD series was consistent well with other documentary evidences and reconstructed climate series in China for 1131–1270,which may reflect the influence on the climate over most regions of China imposed by the Pacific Decadal Oscillation(PDO).
文摘SINCE December 2025,Urumqi City and Altay Prefecture in northwest China’s Xinjiang Uygur Autonomous Region,and northeast China’s Jilin Province have both entered their snow seasons.The snow holidays(for primary and secondary school students)in Urumqi and Altay ran from December 1 to 5.When combined with the preceding and following weekends,the holiday extended to nine days.
文摘Yiwu merchants ride a winter sports boom as“Made in China”winter gear heats up the global economy.YIWU,located in east China’s Zhejiang Province,is globally renowned as a hub for small commodities.This winter,its snow and ice sports products are generating a surge in business.Products such as snowboards,ski goggles,and ski poles are drawing an increasing number of merchants worldwide for purchases.
基金supported by the National Key Research and Development Project of China(2025YFE0103300)the National Natural Science Foundation of China(W2412135)+2 种基金the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2024D01A143,2025D01B165)the China Postdoctoral Science Foundation(GZC20250226)the S&T Innovation and Development Project of Information Institution of Ministry of Emergency Management,China(2024506).
文摘Tajikistan,a mountainous country and a vital water tower for Central Asia,is becoming increasingly vulnerable to snow drought under climate change,threatening its snow-and glacier-fed streamflow.Yet,the impacts of snow drought on the regional hydrology remain insufficiently understood.In this study,we integrated multisource data,including the Fifth Generation European Centre for Medium-Range Weather Forecasts Atmospheric Reanalysis for Land Applications(ERA5-Land)data and hydrological station data,to systematically assess the snow drought patterns and their impacts on streamflow during 1950–2023.We identified snow drought events based on precipitation and snow fraction anomalies relative to climatological means and classified them into warm snow drought,dry snow drought,and warm&dry snow drought.The results revealed that snow drought was a recurrent phenomenon,occurring in 51.70%of the years during the study period,with warm&dry snow drought accounting for 21.90%of the total events.Both the frequency and severity exhibited pronounced spatial variability,largely governed by the elevation and snowfall fraction.Specifically,the frequency of warm snow drought was negatively correlated with the snowfall fraction,decreasing on average by 0.20 per unit increase in snowfall fraction,whereas the frequency of dry snow drought was positively correlated,increasing by 0.07 per unit increase.The streamflow analysis results demonstrated that snow drought typically reduced the warm-season discharge by 5.00%–18.00%in certain rivers,thereby exacerbating the water stress during the dry season.The results of this study advance our understanding by explicitly linking the types of snow drought to hydrological responses in Central Asia’s high mountains,providing a scientific basis for climate adaptation and sustainable water resource management in Tajikistan.
文摘China’s winter sports boom creates jobs and spurs economic growth,bringing substantial benefit to the general public,local governments,and businesses.CHINA’s ice and snow economy,riding on the winter sports boom,is stimulating consumption across the country,fueling regional development and creating new industrial ecosystems.This trend perfectly matches one of China’s key tasks for 2026.
文摘How is a nation’s embrace of snow and ice shaping a new cultural identity and igniting a multi-trillion-yuan economic boom?ADRIAAN Smit now cannot imagine a life without snowboarding,a passion that has become central to his world.He is excited to witness how winter sports are fostering a new winter culture in China.Listening to Smit speaking so enthusiastically about the slopes,one might assume he was raised in a region where snow sports are a way of life,but the fact is quite the contrary.
文摘Yiwu merchants ride a winter sports boom as“Made in China”gear heats up the global economy Yiwu,located in east China’s Zhejiang Province,is globally renowned as a hub for small commodities.This winter,its snow and ice sports products are generating a surge in business.
文摘As the wheel of time turns toward the year's end and the beginning of the new year,the snow-kissed land of Xizang gracefully unveils its grandeur and offers a feast of wonders for all to explore.Here,crystalline ice and snow form a celestial winter realm.Amid the biting seasonal winds,o month-long New Year celebration brings one o deep,heartfelt warmth.Rarely witnessed elsewhere in the world,this collection of New Year customs stands as both a cultural marvel and a warm gift that the plateau bestows upon the depths of winter.
文摘PHOTO NEWS Unforgettable Winter Break Tourists take selfies in front of snow sculptures in the Fenghuang Mountain Scenic Area,Yakeshi City in Inner Mongolia Autonomous Region,on December 7,2025.
文摘China’s winter sports boom is expanding beyond its traditional northern heartlands,fueling a dynamic ice-snow economy and culture nationwide.This seasonal surge is driven by sustained investment and innovative development models that are turning cold climates into hot economic opportunities.
文摘Conversation A(in the coffee shop)Zach:What are you doing,Emily?I'm planning an event.I'm calling it“Neighborhood Snow Party!”Emily:Zach:Fun!When is it?It's this Saturday,January 31st.What's the time and place?It's from 10 a.m.to 4 p.m.at Emily:Zach:Emily:Green Hill Park.Zach:I can go!
基金supported by the National Key R&D Program of China[grant number 2022YFF0801603]the Natural Science Foundation of China[grant number 41905074].
文摘Due to the high elevation and cold climate of the Tibetan Plateau,the western region retains extensive snow cover during the summer,which can exhibit rapid variability over the course of just a few days.This study utilizes numerical experiments to investigate the atmospheric response to extreme Tibetan Plateau snow cover(TPSC)events on a subseasonal timescale during summer.The results indicate that the subseasonal variations in TPSC exert limited impact on nonlocal atmospheric circulation and temperature during this period.Nevertheless,local surface energy and atmospheric temperature exhibit rapid cooling responses to increased snow cover.Specifically,an increase in snow cover over the western Tibetan Plateau leads to a sharp rise in surface albedo,resulting in a reduction in land surface energy and a negative response in the diabatic heating rate from the surface to 350 hPa locally.This negative diabatic heating response subsequently causes a decline in both surface and overlying atmospheric temperatures.The temperature response is confined to the western Tibetan Plateau and extends vertically from the surface to approximately 350 hPa.These extreme TPSC events and their associated atmospheric impacts occur within a two-week timescale.
基金The Third Scientific Expedition Project in Xinjiang,No.2022xjkk0905Project Commissioned by the General Administration of Sport of ChinaProject Commissioned by the Ministry of Culture and Tourism of the People’s Republic of China。
文摘This study proposes a framework for the concept of“new quality productive forces”in the ice and snow economy(ISE)as a strategic response to global climate change and the demands of technological and industrial transformation for high-quality development.These new quality productive forces in the ISE have developed alongside the zonal distribution of natural resources,strictly adhere to ecological principles,and integrate value transformation mechanisms specific to ice and snow resources.Their development is projected to generate multiple benefits across ecological,economic,and social dimensions.The new quality productive forces in the ISE are characterized by technology-driven resource development,synergistic integration across the entire ice and snow industry value chain,and a focus on high-quality,green growth.Grounded in geography and economics,the new quality productive forces in the ISE link scientific innovation,the reallocation of productive factors,and industrial upgrading within the context of resource constraints.Furthermore,they expand the growth potential of the ISE by fostering new production relations through digital,intelligent,and green integration,while advancing low-carbon,sustainable development under the guiding principle that“ice and snow landscapes are also mountains of gold and silver.”For China's ISE,these new quality productive forces emphasize rigorous resource protection,balanced human-environment relationships,a resilient integrated supply chain framework,and an efficient“dual circulation”economic model.Practical strategies include integrating production factors,optimizing spatial resource allocation,fostering industrial synergy,and adapting production relations,all aimed at advancing the sustainable and high-quality development of China's ISE.
文摘This is an in-depth journey to experience the ice and snow of Changbai Mountain.In these few days,you will explore Changbai Mountain and enjoy powder skiing;gallop on the ski trail;watch the stunning wonders of snow rime on thousands of trees;conquer the ice and snow wilderness on a snowmobile and start an in depth magical mystery tour in lilin Province.
文摘"The fairyland of ice and snow","the Garden of Eden in the depth of snow mountains","mythical wonderland in eastern Nyainqentanglha",or"a family of snow peaks"...Are those phrases often used by netizens enough to describe Sapu Mountain?
基金funded by the National Natural Science Foundation of China(Grant Nos:42125604&42171143)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0201)。
文摘The snow density is a fundamental variable of the snow physical evolution processes,which can reflect the snowpack condition due to the thermal and gravitational compaction.Snow density is a bridge to transfer snow depth to snow water equivalent(SWE)for the snow water resources research.Therefore,it is important to understand the spatiotemporal distribution of snow density for the appropriate estimation of SWE.In this study,in situ snow densities from more than 6,000 stations in the Northern Hemisphere were used to analyze the spatial and temporal variations in snow density.The results displayed that snow density varied spatially and temporally in the Northern Hemisphere,with range of below 0.1 to over 0.4 g/cm^(3).The average snow densities in the mountainous regions of western North America,southeastern Canada,and Europe range from approximately 0.24 to 0.26 g/cm^(3),which is significantly greater than the values of 0.16–0.17 g/cm^(3)observed in Siberia,central Canada,the Great Plains of the United States,and China.The seasonal growth rates also present large spatial heterogeneity.The rates are over 0.024 g/cm^(3)per month in Southeastern Canada,the west mountain of North America and Europe,approximately 0.017 g/cm^(3)per month in Siberia,much larger than approximately 0.004 g/cm^(3)per month in other regions.Snow cover duration is a critical factor to determine the snow density.This study endorses the small snow density in China based on meteorological station observations,which results from that the meteorological stations are dominantly distributed in plain areas with relative short snow cover duration and shallow snow.
基金funded by the Third Xinjiang Scientific Expedition Program(2021xjkk1400)the National Natural Science Foundation of China(42071049)+2 种基金the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2019D01C022)the Xinjiang Uygur Autonomous Region Innovation Environment Construction Special Project&Science and Technology Innovation Base Construction Project(PT2107)the Tianshan Talent-Science and Technology Innovation Team(2022TSYCTD0006).
文摘Snow cover plays a critical role in global climate regulation and hydrological processes.Accurate monitoring is essential for understanding snow distribution patterns,managing water resources,and assessing the impacts of climate change.Remote sensing has become a vital tool for snow monitoring,with the widely used Moderate-resolution Imaging Spectroradiometer(MODIS)snow products from the Terra and Aqua satellites.However,cloud cover often interferes with snow detection,making cloud removal techniques crucial for reliable snow product generation.This study evaluated the accuracy of four MODIS snow cover datasets generated through different cloud removal algorithms.Using real-time field camera observations from four stations in the Tianshan Mountains,China,this study assessed the performance of these datasets during three distinct snow periods:the snow accumulation period(September-November),snowmelt period(March-June),and stable snow period(December-February in the following year).The findings showed that cloud-free snow products generated using the Hidden Markov Random Field(HMRF)algorithm consistently outperformed the others,particularly under cloud cover,while cloud-free snow products using near-day synthesis and the spatiotemporal adaptive fusion method with error correction(STAR)demonstrated varying performance depending on terrain complexity and cloud conditions.This study highlighted the importance of considering terrain features,land cover types,and snow dynamics when selecting cloud removal methods,particularly in areas with rapid snow accumulation and melting.The results suggested that future research should focus on improving cloud removal algorithms through the integration of machine learning,multi-source data fusion,and advanced remote sensing technologies.By expanding validation efforts and refining cloud removal strategies,more accurate and reliable snow products can be developed,contributing to enhanced snow monitoring and better management of water resources in alpine and arid areas.
文摘In winter,the weather is usually cold and everything seems a bit dull.Butthe sun in winter is special.When the sun shines brightly in the clear blue sky,it brings warm(1)to thecold world.The golden sunlight spreads here and there and it makes the whitesnow shine like diamonds.Although the trees are usually bare in winter,but(2)they look beautiful with the sunlight falling on them.
