ALBERT

Description: Within the framework of the WMO-SPICE (Solid Precipitation Intercomparison Experiment) at the Formigal-Sarrios test site located in the Pyrenees mountain range of Spain, the Thies tipping bucket precipitation gauge was assessed against the SPICE reference. The Thies gauge is the most widely-used precipitation gauge by the Spanish Meteorological State Agency (AEMET) for the measurement of all precipitation types, including snow. It is therefore critical that its performance be characterized. The first objective of this study is to derive transfer functions based on the relationships between catch ratio and wind speed and temperature. Multiple linear regression was applied to 1 h and 3 h accumulation periods, confirming that wind is the most dominant environmental variable affecting the gauge catch efficiency, especially during snowfall events. At wind speeds of 1.5 m s−1 the average catch ratio was 0.7. At 3 m s−1, the average catch ratio was 0.5, and was even lower for temperatures below −2 ºC and decreased to 0.2 or less for higher wind speeds. Following this, this study outlines two areas in Northern Spain that exhibit different catch ratios under weather conditions leading to snowfall events, highlighting the importance of how the precipitation gauge behaves in various conditions.

Description: Prior to the beginning of the World Meteorological Organization’s (WMO) Solid Precipitation Inter-Comparison Experiment (SPICE, 2013-2015), two precipitation measurement intercomparison sites were established in Saskatchewan. Caribou Creek, located in the southern Boreal forest, and Bratt’s Lake, located in the southern plains, were meant to be a contribution to the international SPICE project but also to examine national and regional issues in measuring solid precipitation. It is also fortunate that the Changing Cold Regions Network (CCRN) Special Observation and Analysis Period (SOAP) occurred from 2014 to 2015, overlapping with the SPICE intercomparison period. Following SPICE, the two Saskatchewan sites continued to collect core meteorological data (temperature, humidity, wind speed, etc.) as well as precipitation observations via several automated gauge configurations, including the WMO automated reference and the Meteorological Service of Canada's (MSC) network gauges. In addition, manual snow surveys to collect snow cover depth, density, and water equivalent were completed over the duration of the winter periods at the northern Caribou Creek site. Starting in the fall of 2013, the core intercomparison precipitation and ancillary data continued to be collected through the winter of 2017. Automated observations were obtained at a temporal resolution of 1 minute, subjected to a rigorous quality control process, and aggregated to a resolution of 30 minutes. The manual snow surveys at Caribou Creek were generally performed every second week during the SPICE field program and reduced to monthly following SPICE. The Saskatchewan SPICE data are available at https://doi.org/10.18164/63773b5b-5529-4b1e-9150-10acb84d59f0. The data collected at the Saskatchewan SPICE sites will continue to be useful for transfer function testing, Numerical Weather Prediction and hydrological forecasting verification, ground truth for remote sensing applications, as well as providing reference precipitation measurements for other concurrent research applications in the cold regions.