基于FY-3号气象卫星的中国典型积雪覆盖区时空动态研究

Study on spatiotemporal dynamics of snow cover based on FY-3 meteorological satellite in typical regions of China

摘要:

积雪作为地球上水资源的贮存方式之一，对土壤湿度和淡水分布产生着重要的影响。中国领土南北跨越纬度约50度，积雪分布广泛，研究积雪时空动态具有重要意义。本文基于风云三号气象卫星的积雪产品数据（Snow Cover，SNC），提出了基于经验模态分解的趋势提取方法，探讨了中国2010-2019年的积雪时空动态及变化趋势。结果表明：1）中国积雪覆盖频率（Snow Cover Frequency ,SCF）具有显著的季节性特征，呈现先增加后减少的特点，每年二、三月达到当年最大SCF，东北的年际SCF有显著下降的趋势，其他地区变化不大。2）内蒙古和新疆的积雪覆盖率（Snow Cover Rate，SCR）近10年分别下降了1.6%和1.5%，其他地区SCR变化不显著；主要积雪覆盖区SCR均在2016年发生由增加到减少的转变。本研究对掌握中国典型积雪覆盖区的时空动态以及后续探讨积雪与气温、降水等影响因子的关系有重要意义。同时通过风云气象卫星的数据得出相关成果，加强风云三号卫星观测资料的应用。 关键词: 风云三号气象卫星；积雪覆盖频率；积雪覆盖率；经验模态分解；时空动态

Abstract:

As an important part of the cryosphere, snow cover has an important impact on atmospheric circulation and the hydrologic cycle. 98% of the seasonal snow in the world is located in the northern hemisphere. Eurasia continent is the main snow area in the Northern Hemisphere. China has a vast territory with nearly 50 degrees latitude across from north to south, and snow is widely distributed, which is important for studying spatial and temporal dynamics of snow cover. This paper proposes a trend extraction method based on empirical mode decomposition (EMD) based on the Snow Cover (SNC) data of FY-3 meteorological satellite and discusses the temporal and spatial characteristics and variation trends of Snow Cover in China during the past decade (2010-2019). The results show that: 1) China"s Snow Cover Frequency (SCF) has significant seasonal characteristics, which increases first and then decreases, and reaches the maximum SCF in February and March each year. The inter-annual SCF in northeast China has a significant trend of decline, but there is little change in other regions. 2) Snow Cover Rate (SCR) in Inner Mongolia and Xinjiang has decreased by 1.6% and 1.5% in the last decade, respectively. SCR in other areas has not changed significantly. SCR in main snow covered areas changed from increase to decrease in 2016.This study is of great significance to understand the spatial and temporal dynamics of typical snow cover areas in China and to further explore the relationship between snow cover and air temperature, precipitation, and other influential factors. At the same time, relevant results are obtained from the data of the Wind Cloud Meteorological Satellite, and the application of the observation data of the FY-3 satellite is strengthened.