Variability in snow cover phenology in China from 1952 to 2010

Abstract

Abstract. Daily snow observation data from 672 stations, particularly the 352 stations with over ten annual mean snow cover days (SCD), during 1952–2010 in China, are used in this study. We first examine spatiotemporal variations and trends of SCD, snow cover onset date (SCOD), and snow cover end date (SCED). We then investigate SCD relationships with number of days with temperature below 0 °C (TBZD), mean air temperature (MAT), and Arctic Oscillation (AO) index, the latter two being constrained to the snow season of each snow year. The results indicate that the heavy-snow years for the entire country include 1955, 1957, 1964, and 2010, and light-snow years include 1953, 1965, 1999, 2002, and 2009. The reduced TBZD and increased MAT are the main reasons for the overall delay of SCOD and advance of SCED since 1952, although it is not necessary for one station to experience both significantly delayed SCOD and early SCED. This explains why only 15% of the stations show significant shortening of SCD, while 75% of the stations show no significant change in the SCD trends. This differs with the overall shortening of the snow period in the Northern Hemisphere previously reported. Our analyses indicate that the SCD distribution pattern and trends in China are very complex and are not controlled by any single climate variable examined (i.e. TBZD, MAT, or AO), but a combination of multiple variables. It is found that the AO index has the maximum impact on the SCD shortening trends in Shandong Peninsula, Changbai Mountains, and North Xinjiang, while the combined TBZD and MAT have the maximum impact on the SCD shortening trends in the Loess Plateau, Xiaoxingganling, and Sanjiang Plain.

No evidence of widespread decline of snow cover on the Tibetan Plateau over 2000–2015

“…Based on the daily snow observation data from meteorological stations, Ke et al . examined the variability of snow cover phenology in China during 1952–2010 17 . They found that snow cover significantly started later and melted earlier with the increasing temperature, but SCD did not show significant trend within this time span.…”

“…In addition, previous studies mainly focused on changes in the extent, duration and depth of snow cover 26 , 27 , while spatial and temporal patterns of snow cover start (SCS) and melt (SCM) dates of the TP have not been well understood. Studies have systematically analyzed the variability of snow cover phenology in China 17 and the Northern Hemisphere 12 , using meteorological stations. However, these stations distribute unevenly and predominantly located in low-altitude areas of the TP.…”

Spatial and Temporal Adaptive Gap-Filling Method Producing Daily Cloud-Free NDSI Time Series

“…The 1-cm SD threshold was adopted under a wide range of snow conditions in previous studies [52], [53]. Moreover, Ke et al [54] indicated that a shallow snow cover (SD < 1 cm) can reduce the data reliability in snow-related studies in China. Therefore, we defined SD ≥ 1 cm as snow and as snow-free otherwise.…”

Trends and variability in snowmelt in China under climate change

“…China covers a vast area and a variety of climate regions, and its snow-covered regions are widely distributed geographically with evident spatial differences (Tan et al, 2019). Northern Xinjiang, Northeastern China-Inner Mongolia (hereafter referred to as Northeast China) and the Tibetan Plateau are the three main regions with stable snow cover in China (Ke et al, 2016;Fig. 1a).…”