| 28 Jan 2026
Proposed improvement of the detection and measurements of light precipitation in the Canadian Arctic
Abstract. Snowfall during the extended cold season experienced in Arctic regions is the primary contributor to snowpack evolution, terrestrial components of the water cycle, and many melt-season hydrologic phenomena. Despite this importance, solid precipitation measurements in the Arctic are challenging; frequent periods of light precipitation are often difficult to measure with existing gauge networks, and result in under-estimations of total snowfall during a winter season. This study analyzes the measurement of solid precipitation at the Trail Valley Creek Research Station in the Canadian Northwest Territories, using a weighing precipitation gauge, and micro rain radar. The study period runs from 4 November 2023 to 30 April 2024, with an intensive observation period from 16 March to 2 April 2024, during which detailed manual observations improved our understanding of instrument performance in arctic conditions. The already established weighing gauge was used as the reference for the study and measured a total snowfall (snow water equivalent) during the study period of 68 mm, which increased to 190 mm after corrections for wind and snowfall intensity. Manual observations coupled with radar, however, confirm the difficulty of measuring light precipitation. We present a method of on-site calibration for the reflectivity-snowfall relationship for the micro rain radar, that we use to estimate the low-rate (< 0.2 mm hr-1) snowfall amounts that are commonly missed by weighing gauges. Adding these trace amounts of precipitation, the total snowfall amount increased by another 24 %. While more work is required to confirm these methods in Arctic environments, this study contributes to a better understanding of current measurement systems and can be used to enhance snowfall estimations.
This paper highlights some much needed research on the impact of precipitation gauge measurement bias as it relates to small but significant solid precipitation amounts in cold regions and speaks for the need for techniques to augment conventional gauge measurements of solid precipitation in harsh environments.
I do have a comment about the statement made on Page 10 (lines 230-233) about Geonor gauge sensitivity. If interval precipitation is being calculated as the bucket weight differential between time T and time T-1, you are correct to assume that precipitation collected in the bucket that is less than the sensitivity of the gauge will not be reported at time T. However, unless evaporation occurs, that unreported precipitation that has accumulated in the bucket will likely register as an increase in bucket weight in a later interval, usually following more precipitation. The mass is conserved. This means that the timing of the precipitation is impacted, but not the long term total, so those small accumulations are ultimately shown in your accumulated time series in Figure 5. As you point out, many small amounts still go unreported because of wind undercatch (snow that never falls into the bucket in the first place) but this is unrelated to gauge sensitivity.
Also, if timing of precipitation is critical for comparison with the MRR, your raw bucket weight filtering technique may also impact the distribution of measured precipitation between adjacent intervals. Depending on the severity of the noise in your raw data and the effectiveness of your noise filter, this may have a more significant impact on interval totals than gauge sensitivity and should probably be mentioned as a source of uncertainty in your comparisons.