*4.3. Strengths and Limitations*

The strengths of this study compared with the previous can be summarized as the following:


previously (Section 4.1), since rapid snow accumulation and ablation processes in spring always last for less than one week. Thus, the monthly mean data, which are commonly used in other studies [35,43,59], would easily smooth the snow and feedback processes. In addition, surface albedo decrease associated with loss of snow cover is estimated precisely on temporal scale, which offers guidance for model optimization.

4. The block bootstrap test is used effectively to reduce the uncertainty of snow albedo feedback. Considering the fact that most observation-based studies are short in time duration, a simple linear regression [28,35,43] to compute snow albedo feedback and its confidence limits would probably give misleading results due to the random variations of variables. By enlarging the sample amount and enhancing the number of tests (10,000 times in our case), the block bootstrap test should have obtained more reliable results.

Our study has some limitations that could lead to the uncertainties of the results:

