Inconsistency in precipitation measurements

Revisions and Responses for: 1 Inconsistency in precipitation measurements across Alaska and Yukon 2 border 3 L. Scaff, D. Yang, Y. Li, and E. Mekis 4 5 From: Anonymous Referee #1 6 Received and published: 14 August 2015 7 8 General Comments This study compared precipitation observations along international borders to investigate the 9 impact of gauge type biases on the distribution of precipitation. The use of observed and corrected precipitation, in 10 my opinion, is an interesting topic worthy of exploring. This is particularly true for the documented gradient 11 difference, which I found to be the most novel part of the manuscript. However, these results are limited by the very 12 small sample size; a set of two groups. In addition, I found the manuscript lacking details in some locations, which 13 may be helpful to prospective readers. For instance, the authors never comment on whether precipitation gradients 14 across the U.S.-Canada border should resemble the corrected or uncorrected gauge data results. Also missing was a 15 brief description of how the Yang et al. (2005) corrections were applied. This is of interest since U.S. National 16 Weather Service (NWS) stations do monitor surface winds, which may be necessary to evaluate wind related biases. 17 Moreover, I recommend the manuscript be considered for publication pending minor revisions; however, I’m 18 concerned about the impact of the study considering the small sample size. 19 20 We greatly appreciate your time and comments, and we have improved the paper with the revision. 21 22 23 Specific Comments 24 25 1). The most interesting aspect of this study is the gradient differences between corrected and uncorrected gauge 26 data. Unfortunately, this analysis is limited by the selection of a study area, which in my opinion is too narrowly 27 focused on the Alaska and Yukon border. It is not clear in the manuscript why the southern region along the U.S. 28 and Canada border was excluded. Do the authors expect differences along southern border to differ from the AK and 29 Yukon comparison? Does the Yang et al. (2005) dataset not include stations along this border? Please explain. 30 31 Re: The main objective of this study is to examine and quantify the changes in precipitation gradient across 32 the AK and YK border due to bias corrections of US and Canadian gauge observations. Many studies, 33 including Yang et al., (2005), clearly show that the biases in gauge precipitation measurements are very 34 high (up to 80-100%) for the cold regions, particularly in areas with light snowfall and high winds. 35 Relative to the AK-YK border, this region are cold with more snowfall compared with southern US36 Canada, meaning higher biases due to wind induced gauge undercatch, and thus significant changes and 37 difference between measured and corrected precipitation across AK-YK border. This is the reason why our 38 study specifically selected such a region, i.e. to focus on an area with the biggest problem in precipitation 39 measurements incompatibility. This study used data from 5 climate stations in 2 groups in the northern and 40 central AK-YK regions. The selected stations very well represent climate gradient across the region, and 41 the results from these sites are sufficient for the methodology development and demonstration of new 42 knowledge in precipitation regime and distribution. 43 44