Snowfall Measurement Challenges WMO SPICE Solid Precipitation Intercomparison Experiment

Transcription

1 WMO World Meteorological Organization Working together in weather, climate and water Snowfall Measurement Challenges WMO SPICE Solid Precipitation Intercomparison Experiment Global Cryosphere Watch Snow Watch Workshop Toronto, Canada Jan 28, 2013 Rodica Nitu Chair and Project Lead WMO SPICE WMO; Commission for Instruments and Methods of Observation

2 Summary Project description; Objectives; Participation; Links with the Remote Sensing Communities. Jan 28,

3 WMO WMO SPICE WMO - Commission for Instruments and Methods of Observation (CIMO): two-winter seasons, multi-site experiment; International Organizing Committee (IOC): Canada, China, Germany, Italy, New Zealand, Russia, Switzerland, USA. Will investigate the in-situ measurement and reporting of: Precipitation amount» over various time periods (minutes, hours, days, seasons),» as a function of precipitation phase (liquid, solid, mixed); Snow on the ground (snow depth)» linkages between snow on the ground and snowfall Jan 28,

4 Motivation and Goals Snowfall measurements are confounded by many factors (shield, gauge, heating, wind, microphysics, etc.) SPICE will contribute to improving the point measurements of snowfall and snow depth measured with automated gauges, at high time resolution. will foster linkages with radar and satellite communities, to enable areal and global estimates. Jan 28,

5 WMO-SPICE Objectives (1) Define field references using automatic instruments, over a range of temporal resolutions (daily to minutes). Characterize currently operational and emerging automatic instruments measuring snow; gauge/shield combination for different collection conditions/climates; sources and magnitude of errors; Derive adjustments to be applied to measurements, as a function of wind, temp, precipitation type; Jan 28,

6 WMO-SPICE Objectives (2) Assess the minimum practicable temporal resolution for reporting a valid snow measurement; Configure a comprehensive intercomparison dataset for further data mining (e.g., radar- and/or satellite-based snowfall estimation). Identify the available remotely sensed precipitation data, reference it as part of the intercomparison dataset. Jan 28,

7 : 1st WMO Solid Precipitation Intercomparison WMO/TD - No. 872/98, B.E. Goodison, P. Louie and D. Yang (Canada); Recommended Secondary Field Reference; Characterised the national standard measurement methods. Recommended methods for adjusting solid precipitation measurements, function of daily wind speed (Ws) at gauge height, and daily air temperature (Tmax, Tmin, Tmean) Jan 28,

8 SPICE Project plan Official Start: Dec Minimum 2 winter seasons; WMO Final Report: 2016 and include: Results relative to project objectives; Site specific results; Sites may continue the experiments. Preliminary/partial results published prior to Final Report. Feb 2013: new call for expressions of interest; Jan 28,

9 Participating Sites 12 countries: 15 field sites, one laboratory; Northern Hemisphere: Canada, Finland, Japan, Norway, Russia, Poland, Switzerland, USA, Italy,. Southern Hemisphere: Australia, Chile, New Zealand; Jan 28,

10 Participating Sites (1) Alpine Climates: Australia: Guthega Dam WS (New South Wales), Snowy Hydro Limited, 1586 m Chile: Tapado WS, Región de Coquimbo, Centro de Estudios Avanzados en Zonas Áridas (4318 m) New Zealand: Mueller Hut WS, National Institute of Water and Atmospheric Research Ltd (1818 m) Poland: Hala Gasienicowa WS, Institute of Meteorology and Water Management (1520 m) Norway: Haukeliseter, Norwegian Meteorological Institute: (990 m) Switzerland: Weissfluhjoch (Davos), MeteoSwiss and Swiss Institute for Snow and Avalanche Research (SLF), 2500 m. Jan 28,

11 Participating Sites (2) Arctic Climate: Finland: Sodankyla ARC : Latitude : 67, Elevation : 179 m, FMI. Continental Climate: Canada; Environment Canada: Bratt s Lake (585 m), Egbert (251 m), Caribou Creek (517 m USA: NOAA/NCAR: Boulder (CO), 1740 m; Russia: Roshydromet: Valdai (194 m) and Voljskaya, Nijny Novgorod Reg (101 m); Japan: Joetsu Agricultural Research Center: (elevation: 11 m), total snowfall 600 mm, National Agriculture and Food Research Organization (NARO), Rikubetu, Hokkaido, National Institute of Polar Research (NIPR). Jan 28,

12 Participating Instruments Includes currently operational and emerging technologies. Instruments and configurations provided by host organizations and by 17 manufacturers: Catchment type: Weighing Gauges, Tipping Buckets; Particle disdrometers, hot plate; Acoustic and laser snow depth sensors; Wind shields: (type: Alter, Tretyakov, Belfort, wood), and configurations (single, double, small wooden); Gauges equipped with heating in various configurations; Jan 28,

13 Measurement of Total Precipitation 2008 WMO CIMO Survey on instruments for measuring solid precipitation at AWS Results: IOM Report #102, WMO/TDNo g/www/imop/publications- IOM-series.html; Tipping Bucket type gauges: 28 models; Sensitivity 0.1 to 0.5 mm; Some heated, some not; Windshields: 31% (30%, USA, Japan + 1% elsewhere) Weighing Gauges: 6 models, 6 manufacturers; capacity: mm; Some heated, some not; 78% use single wind shields (Alter, Tretyakov, Nipher); Jan 28,

14 Motivation: Total Precipitation: snow vs. rain Feb 11-12, 2009: T min = 6.8 deg C Jan 28-29, 2009: T max = deg C h Accumulation (mm): RAIN Feb 11-12, 2009 Weighing Gauges h accumulation (mm): SNOW Jan 28-29, Tipping Buckets Disdrometer

15 Secondary Field Reference The 1st WMO Solid Precipitation Intercomparison : DFIR (Double Fence International Reference) a complete system: Octagonal double-fence (DFIR-fence) Tretyakov gauge+shield placed in its centre. SPICE: Double Fence Automatic Reference (DFAR): a field reference configuration using: Octagonal double-fence (DFIR-fence) An automatic gauge (model not prescribed) Other instruments. Jan 28,

16 Adjustments specific to gauge + shield GEONOR AS T-200BM3 (1500mm) Meteoservis v.o.s MRW500 CAE S. p. A PMB25R Environmental Measurements Ltd. UPG1000 Jan 28,

17 Non-Catchment type Instruments AdolfThies GmbH&Co KG Laser Precipitation Monitor OTT Hydromet GmbH PARSIVEL 2 Droplet Measurement Technologies Meteorological Particle Sensor Campbell Scientific PWS100 Jan 28,

18 Snow Depth and SWE Instruments Campbell Scientific SR50ATH-316SS Felix Technologies SL300 ESW GmbH Jenoptik Hydrological Services America: Sommer GmbH & Co KG USH-8 Snow Water Equivalent Campbell Scientific CS725 Jan 28,

19 SPICE and the Remote Sensing Communities SPICE Outcome: Ensure that available remotely sensed precipitation data is referenced as part of the intercomparison dataset. Site Managers: inform scientists (radar, satellite, data assimilation, etc) of the availability of SPICE high quality point measurement snowfall data: development or validation of reflectivity-snowfall relationships or data assimilation analysis techniques and products, etc. National reports may report on these results, but no formal analysis plan. Jan 28,

20 Opportunities for collaboration Global Precipitation Mission (GPM) Ground Validation: Canadian SPICE sites Sodankyla (Finland) Guthega Dam (Australia) Global Cryosphere Watch (GCW) Demonstration Project: impact of automation on the measurement of solid precipitation; NOAA - Environment Canada Cooperation Steering Committee (CSC): proposal to further validate and improve satellite derived snowfall detection and snowfall rate products. Essential: High quality radar and gauge snowfall measurements (detection, water equivalent rate, snow particle size and shape, etc.). Jan 28,

21 Thank you! Questions? CE.html