Variability in snow cover phenology in China from 1952 to 2010

Chang-Qing Ke,Hongjie Xie,Dong-Hui Ma,Xiu-Cang Li,Xun Liu,Cheng Kou

doi:10.5194/hess-20-755-2016

Abstract

Abstract. Daily snow observation data from 672 stations in China, particularly the 296 stations with over 10 mean snow cover days (SCDs) in a year during the period of 1952–2010, are used in this study. We first examine spatiotemporal variations and trends of SCDs, snow cover onset date (SCOD), and snow cover end date (SCED). We then investigate the relationships of SCDs with number of days with temperature below 0 °C (TBZD), mean air temperature (MAT), and Arctic Oscillation (AO) index. The results indicate that years with a positive anomaly of SCDs for the entire country include 1955, 1957, 1964, and 2010, and years with a negative anomaly of SCDs include 1953, 1965, 1999, 2002, and 2009. The reduced TBZD and increased MAT are the main reasons for the overall late SCOD and early SCED since 1952. This explains why only 12 % of the stations show significant shortening of SCDs, while 75 % of the stations show no significant change in the SCDs trends. Our analyses indicate that the distribution pattern and trends of SCDs 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 has the maximum impact on the shortening trends of SCDs in the Shandong peninsula, Changbai Mountains, Xiaoxingganling, and north Xinjiang, while the combined TBZD and MAT have the maximum impact on the shortening trends of SCDs in the Loess Plateau, Tibetan Plateau, and Northeast Plain.

Highlights

Snow has a profound impact on the surficial and atmospheric thermal conditions, and is very sensitive to climatic and environmental changes, because of its high reflectivity, low thermal conductivity, and hydrological effects via snowmelt (Barnett et al, 1989; Groisman et al, 1994)
We first characterise the spatial patterns of change in the snow cover days (SCDs), snow cover onset date (SCOD), and snow cover end date (SCED) in different regions of China; we examine the sensitivity of SCDs to the number of days with temperature below 0 ◦C (TBZD), the mean air temperature (MAT), and the Arctic Oscillation (AO) index during the snow season
In the Daxinganling, Xiaoxingganling, and Changbai Mountains of Northeast China, there are more than 90 annual mean SCDs, corresponding to a relatively long snow season

Summary

Introduction

Snow has a profound impact on the surficial and atmospheric thermal conditions, and is very sensitive to climatic and environmental changes, because of its high reflectivity, low thermal conductivity, and hydrological effects via snowmelt (Barnett et al, 1989; Groisman et al, 1994). The extent of snow cover in the Northern Hemisphere has decreased significantly over the past decades because of global warming (Robinson and Dewey, 1990; Brown and Robinson, 2011). Snow cover showed the largest decrease in the spring, and the decrease rate increased for higher latitudes in response to larger albedo feedback (Déry and Brown, 2007). In situ data showed a significant increase in snow accumulation in winter but a shorter snowmelt season over Eurasia (Bulygina et al, 2009). Meteorological data indicated that the snow cover over northwest China exhibited a weak upward trend in snow depth (Qin et al, 2006), with large spatiotemporal variations (Ke et al, 2009; Ma and Qin, 2012).

Methods

Results

Discussion

Conclusion