Study On The Effect Of Light Absorbing Particles On Snow Melting

In the northeast region,when the pollutants are discharged in winter and the snow cover area is reduced,and the snowmelt time is advanced,the light-absorbing particles(black carbon,sand dust and coal ash,etc.)in the snow are deposited by dry and wet to the snow.It can effectively reduce the snow albedo,increase the absorption of solar radiation,further reduce the snow cover area,accelerate the melting of snow,and have a vital impact on the regional water cycle and the global climate.Based on laboratory tests,this paper uses natural snow from January to March 2018 on the campus of Harbin Normal University(Jiangbei Campus).Two kinds of light-absorbing particles existed(deposited surface,uniformly mixed),and artificially added 7 kinds of light-absorbing granular substances(black carbon,sand dust,coal ash,black carbon + sand dust,black carbon +)to the quantitative snow sample.Coal ash,dust+ coal ash,black carbon + sand dust + coal ash),observe the influence and difference of light-absorbing particulate matter on the melting time of snow in each mode,and quantitatively evaluate the influencing factors such as particle size and temperature.The contribution rate of each factor to the snowmelt time indicates that:(1)the light-absorbing particles have a significant influence on the melting time of the snow,and the influence of different particles on the snow melting time is different.Any kind of light-absorbing particles in the snow Exist,the melting time of the snow is less than that of the control group,and as the concentration of the particles increases,the snow melting time decreases.The effect of black carbon and sand dust on the melting time of snow and the difference between his particles is that black carbon is the fastest particle to reduce the melting time of snow,while sand dust is the slowest;(2)light absorption There are differences in the influence of the presence of particulate matter on the melting time of snow(except black coal and black dust coal),which is mainly manifested by the fact that the melting time evenly mixed in the snow is less than the melting time when deposited on the snow surface;(3)The larger the black carbon particle size,the less the snow melting time,and the decreasing speed gradually slows down.When black carbon particle size and concentration act together on snow melting,the contribution of black carbon concentration to the reduction of snow melting time is greater,about 70.925%,while the contribution rate of particle size is only 29.075%;(4)temperature against snow Changes in melting time have a significant impact.At any black carbon concentration level,it shows a characteristic that the snow melting time decreases with the increase of temperature and the decreasing speed gradually slows down.Under the combined influence of temperature and black carbon concentration,the contribution rate of temperature to the reduction of snow melting time is larger,about 73.953%,while the contribution rate of black carbon concentration is only 26.047%.