选取青藏高原(下称高原)东部玛曲、 玛多和垭口3个野外站点的观测资料, 针对不连续积雪过程, 研究高原东部不同季节的积雪过程对地表能量和土壤水热的影响。结果表明: 受积雪高反照率的影响, 高原东部地区各季节降雪后净短波辐射减小, 净辐射较降雪前减小60%~140%; 积雪积累期内感热、 潜热及土壤热通量均减小, 感热通量和土壤热通量出现负值。春、 秋两季积雪过程中, 能量以感热、 潜热和土壤热通量三种形式分配; 冬季积雪过程中能量以感热和土壤热通量分配为主, 潜热通量较小, 日均值在10 W·m-2左右; 而夏季积雪消融期潜热通量较大, 日均值可达80 W·m-2左右。各季节积雪的反复积累和消融过程对大气及土壤均以降温作用为主。秋季降雪后, 气温和浅层土壤温度降低, 当土壤温度降到冰点以下时, 土壤提前进入冻结期; 而春季降雪后, 则可能使得正在发生融化的土壤又再次冻结。冬季晴天积雪过程中, 在积雪积累期, 积雪对土壤起增温作用, 0~20 cm土壤温度日均值升高1~2 ℃, 导致浅层冻结土壤融化, 土壤含水量略增加, 在消融期, 积雪对土壤仍起降温作用; 而冬季阴天积雪对土壤均为冷却作用。夏季积雪积累期较短, 降雪对土壤同样起明显的降温作用。
The observation data from three filed observation stations in the east of the Qinghai-Xizang Plateau (the plateau), namely Maqu, Maduo and Yakou, were selected to study the influence of snow cover processes in different seasons on surface energy and soil temperature(moisture).The results show that, under the influence of high albedo of snow cover, the net shortwave radiation decreases after snowfall in the eastern plateau, and the net radiation decreases by about 60%~140%.Sensible heat, latent heat and soil heat flux decreased in the accumulation period, sensible heat flux and soil heat flux showed negative value.In the course of snow cover in spring and autumn, energy is distributed in the form of sensible heat, latent heat and soil heat flux.In the process of winter snow cover, sensible heat and soil heat flux are the main energy distribution, while latent heat flux is small, with a daily average about 10 W·m-2.However, the latent heat flux in the melting period of summer snow is larger about 80 W·m-2.The process of repeated accumulation and melting of snow cover in each season has a major cooling effect on the atmosphere and soil.After snowfall in autumn, the temperature of air and shallow soil temperature decrease.When the soil temperature drops below the freezing point, the soil enters the freezing period in advance and when snow falls in spring, it could cause the melting soil to freeze again.During the process of snow accumulation on sunny days in winter, snow accumulation plays a warming role on soil, and the daily average temperature of 0~20 cm soil temperature increases by 1~2 ℃, which leads to shallow frozen soil melting and soil moisture content increasing.In the melting stage, snow accumulation still plays a cooling role on soil.Snow cover on cloudy days in winter has a cooling effect on soil.Snow accumulation period in summer is short, and snowfall also has a significant cooling effect on soil.
[1]Barnett T P, Adam J C, Lettenmaier D P, 2005.Potential impacts of a warming climate on water availability in snow-dominated regions[J].Nature, 438(7066): 303-309.DOI: 10.1038/nature04141.
[2]Déry S J, Brown R D, 2007.Recent northern hemisphere snow cover extent trends and implications for the snow-albedo feedback[J].Geophysical Research Letters, 34(22): 60-64.DOI: 10.1029/2007GL031474.
[3]Flanner M G, Shell K M, Barlage M, al et, 2013.Radiative forcing and albedo feedback from the northern hemisphere cryosphere between 1979 and 2008[J].Nature Geoscience, 4(3): 151-155, DOI: 10.1038/ngeo1062.
[4]Goulden M L, 1998.Sensitivity of boreal forest carbon balance to soil thaw[J].Science, 279(5348): 214-217.DOI: 10.1126/science.279.5348.214.
[5]Groisman P Y, Karl T R, Knight R W, 1994.Observed impact of snow cover on the heat balance and the rise of continental spring temperatures[J].Science, 263(5144): 198-200.DOI: 10.1126/science.263.5144.198.
[6]Li W K, Guo W D, Hsu P C, al et, 2016.Influence of the Madden-Julian oscillation on Tibetan Plateau snow cover at the intraseasonal time-scale[J].Scientific Reports, 6(1): 30456.DOI: 10.1038/srep30456.
[7]Li W K, Guo W D, Qiu B, al et, 2018.Influence of Tibetan Plateau snow cover on East Asian atmospheric circulation at medium-range time scales[J].Nature Communication, 9(1): 4243.DOI: 10.1038/s41467-018-06762-5.
[8]Li W K, Qiu B, Guo W D, al et, 2019.Intraseasonal variability of Tibetan Plateau snow cover[J].International Journal of Climatology, 40(7): 3451-3466.DOI: 10.1002/joc.6407.
[9]Peng S S, Piao S L, Ciais P, al et, 2013.Change in snow phenology and its potential feedback to temperature in the Northern Hemisphere over the last three decades[J].Environmental Research Letters, 8(1): 1880-1885.DOI: 10.1088/1748-9326/8/1/014008.
[10]Pu Z X, Xu L, Salomonson V V, 2007.MODIS/Terra observed seasonal variations of snow cover over the Tibetan Plateau[J].Geophysical Research Letters, 34(6): 137-161.DOI: 10.1029/2007GL029262.
[11]Robinson D A, Frei A, Serreze M C, 1995.Recent variations and regional relationships in Northern Hemisphere snow cover[J].Annals of Glaciology, 21: 71-76.DOI: 10.1017/S0260305500015627.
[12]Song L, Wu R G, An L, 2019, Different Sources of 10‐ to 30‐day Intraseasonal variations of autumn snow over western and eastern Tibetan Plateau[J].Geophysical Research Letters, 46(15): 9118-9125.DOI: 10.1029/2019GL083852.
[13]Wang J Y, Luo S Q, Li Z G, al et, 2019.The freeze/thaw process and the surface energy budget of the seasonally frozen ground in the source region of the Yellow River[J].Theoretical and Applied Climatology, 138(3/4): 1631-1646.DOI: 10.1007/s00704-019-02917-6.
[14]Wang T, Peng S S, Ottlé C, al et, 2015.Spring snow cover deficit controlled by intraseasonal variability of the surface energy fluxes[J].Environmental Research Letters, 10(2): 024018.DOI: 10. 1088/1748-9326/10/2/024018.
[15]Xu W F, Ma L J, Ma M N, al et, 2017.Spatial-temporal variability of snow cover and depth in the Qinghai-Tibetan Plateau[J].Journal of Climate, 30(4): 1521-1533.DOI: 10.1175/JCLI-D-15-0732.1.
[16]Zhao H X, Moore G W K, 2004.On the relationship between Tibetan snow cover, the Tibetan plateau monsoon and the Indian summer monsoon[J].Geophysical Research Letters, 31(14): 101-111.DOI: 10.1029/2004GL020040.
[17]Zhou Y, Jiang J, Huang A N, al et, 2013.Possible contribution of heavy pollution to the decadal change of rainfall over eastern China during the summer monsoon season[J].Environmental Research Letters, 8(4): 044024.DOI: 10.1088/1748-9326/8/4/044024.
[18]边晴云, 吕世华, 陈世强, 等, 2016.黄河源区降雪对不同冻融阶段土壤温湿变化的影响[J].高原气象, 35(3): 621-632.DOI: 10.7522/j.issn.1000-0534.2016.00029.
[19]车涛, 刘绍民, 李新, 等, 2019a.高寒草甸生态系统水热通量观测—垭口站涡动相关仪(2015-2017)[DB/OL].国家青藏高原科学数据中心.[2020-07-25].DOI: 10.11888/Meteoro.tpdc. 270399.
[20]车涛, 郝晓华, 戴礼云, 等, 2019b.青藏高原积雪变化及其影响[J].中国科学院院刊, 34(11): 1247-1253.DOI: 10.16418/j.issn: 1000-3045.2019.11.007.
[21]丁霞, 2015.气候变化对黑河上游径流量的影响研究[D].兰州: 甘肃农业大学.
[22]段安民, 肖志祥, 吴国雄, 等, 2014.青藏高原冬春积雪影响亚洲夏季风的研究进展[J].气象与环境科学, 7(3): 94-101.
[23]高荣, 韦志刚, 董文杰, 等, 2003.20世纪后期青藏高原积雪和冻土变化及其与气候变化的关系[J].高原气象, 22(2): 191-196.
[24]郝晓华, 王建, 车涛, 等, 2009.祁连山区冰沟流域积雪分布特征及其属性观测分析[J].冰川冻土, 31(2): 284-292.
[25]侯玉婷, 2013.黑河流域上游高分辨率降水驱动分析及Noah-LSM的径流响应模拟[D].兰州: 兰州大学.
[26]胡豪然, 梁玲, 2013.近50年青藏高原东部冬季积雪的时空变化特征[J].地理学报, 68(11): 1493-1503.DOI: 10.11821/dlxb201311005.
[27]姜琪, 罗斯琼, 文小航,等, 2020.1961-2014年青藏高原积雪时空特征及其影响因子[J].高原气象, 39(1): 24-36.DOI: 10. 7522/j.issn.1000-0534.2019.00022.
[28]柯长青, 李培基, 1998.青藏高原积雪分布与变化特征[J].地理学报, 53(3): 3-5.DOI: 10.3321/j.issn: 0375-5444.1998.03.003.
[29]李丹华, 文莉娟, 隆霄, 等, 2018.黄河源区玛曲3次积雪过程能量平衡特征[J].干旱区研究, 35(6): 1327-1335.DOI: 10. 13866/jazr.2018.06.09.
[30]李栋梁, 王春学, 2011.积雪分布及其对中国气候影响的研究进展[J].大气科学学报, 34(5): 627-636.
[31]李燕, 闫加海, 张冬峰, 2018.青藏高原冬春积雪异常和中国东部夏季降水关系的诊断与模拟[J].高原气象, 37(2): 317-324.DOI: 10.7522/j.issn.1000-0534.2017.00040.
[32]刘晓娇, 陈仁升, 刘俊峰, 等, 2020.黄河源区积雪变化特征及其对春季径流的影响[J].高原气象, 39(2): 226-233.DOI: 10.7522/j.issn.1000-0534.2019.00074.
[33]马丽娟, 秦大河, 2012.1957—2009年中国台站观测的关键积雪参数时空变化特征[J].冰川冻土, 34(1): 1-11.
[34]秦大河, 周波涛, 效存德, 2014.冰冻圈变化及其对中国气候的影响[J].气象学报, 72(5): 869-879.DOI: 10.11676/qxxb2014.080.
[35]王澄海, 王芝兰, 崔洋, 2009.40余年来中国地区季节性积雪的空间分布及年际变化特征[J].冰川冻土, 31(2): 301-310.
[36]王顺久, 2017.青藏高原积雪变化及其对中国水资源系统影响研究进展[J].高原气象, 36(5): 1153-1164.DOI: 10.7522/j.issn. 1000-0534.2016.00117.
[37]王婷, 李照国, 吕世华, 等, 2019.青藏高原积雪对陆面过程热量输送的影响研究[J].高原气象, 38(5): 920-934.DOI: 10.7522/j.issn.1000-0534.2019.0002.
[38]王秀琴, 卢新玉, 王金风, 2013.不同积雪深度下地面温度与雪面温度的相关[J].气象科技, 41(6): 1068-1072.DOI: 10. 19517/j.1671-6345.2013.06.019.
[39]韦志刚, 黄荣辉, 陈文, 等, 2002.青藏高原地面站积雪的空间分布和年代际变化特征[J].大气科学, 26(4): 496-508.
[40]张海宏, 肖建设, 陈奇, 等, 2019.青海省甘德两次降雪过程的微气象特征分析[J].气象, 45(8): 1093-1103.DOI: 10.7519/j.issn: 1000-0526.2019.08006.
[41]张海宏, 姜海梅, 陈奇, 等, 2020.积雪覆盖对高寒草甸土壤温湿及地表能量收支的影响[J].高原气象, 39(4): 740-749.DOI: 10. 7522/j.issn.1000-0534.2019.00072.
[42]赵哈林, 周瑞莲, 赵悦, 2003.雪生态学[M].北京: 海洋出版社.
[43]仲文, 2019.祁连山黑河上游多年冻土区热融喀斯特地表变形监测研究[D].兰州: 兰州大学.