Center for Snow and Avalanche Studies

CSAS Data: Graphs & Plot

Wind | Air Temps | Precip | Snowpack | Soil | Stream flow | Radiation

We measure incoming and reflected shortwave radiation with pyranometers (filtered and unfiltered) at two sites: SBSP (alpine) and SASP (sub-alpine). We also measure longwave incoming radiation with a pyrgeometer at both sites. We have snow surface temperature data to correlate with radiation data.




Plots of “broadband” snow albedo from 1200-1300 hours each day of the winters of 2011,/2012, 2012/2013, 2013,2014, 2014/2015, and 2016/2017 at the Swamp Angel Study Plot (SASP) and Senator Beck Study Plot (SBSP) in Senator Beck Basin Study Area.  Gaps in the data at SASP represent days during which snow covered the up-looking “broad band” pyranometer measuring incoming, short-wave radiation (and SASP sensors were being recalibrated in fall 2013). Wind keeps the SBSP up-looking sensor clear of new snow.  Data at the extreme ends of the plots represent the albedo of bare soil or vegetation on the ground, in the 0.15 to 0.20 range. Broadband albedo is calculated as the ratio of measured solar radiation reflected off the snowpack surface to incident (incoming) solar radiation; these measurements are not corrected for snow grain size effects or for slope and aspect of the reflecting snow surface (~3-4° NE at both sites).

 


This graph presents mid-day snow albedo data from the alpine Senator Beck Study Plot and the subalpine Swamp Angel Study Plot, from October 1, 2014 to June 20, 2015, in conjunction with daily mean discharge measurements at the Senator Beck Stream Gauge, located at the Senator Beck Basin pour point immediately downstream of the Swamp Angel Study Plot.  Gaps in the SASP represent periods when the up-looking radiometer was buried in new snow, before being swept clean immediately after a storm. Albedo values below 0.20 indicate "snow all gone" and represent the albedo of bare soil and tundra.

 


This graph presents mid-day snow albedo data from the alpine Senator Beck Study Plot and the subalpine Swamp Angel Study Plot, from March 1, 2014 to June 20, 2014, in conjunction with daily mean discharge measurements at the Senator Beck Stream Gauge, located at the Senator Beck Basin pour point immediately downstream of the Swamp Angel Study Plot.  Gaps in the SASP represent periods when the up-looking radiometer was buried in new snow, before being swept clean immediately after a storm. Albedo values below 0.20 indicate "snow all gone" and represent the albedo of bare soil and tundra.

 


This graph presents mid-day snow albedo data from the alpine Senator Beck Study Plot and the subalpine Swamp Angel Study Plot, from March 1, 2013 to June 11, 2013, in conjunction with daily mean discharge measurements at the Senator Beck Stream Gauge, located at the Senator Beck Basin pour point immediately downstream of the Swamp Angel Study Plot.  Gaps in the SASP represent periods when the up-looking radiometer was buried in new snow, before being swept clean immediately after a storm. Albedo values below 0.20 indicate "snow all gone" and represent the albedo of bare soil and tundra.

 


This graph presents mid-day snow albedo data from the alpine Senator Beck Study Plot and the subalpine Swamp Angel Study Plot, from March 1, 2012 to July 8, 2012 in conjunction with daily mean discharge measurements at the Senator Beck Stream Gauge, located at the Senator Beck Basin pour point immediately downstream of the Swamp Angel Study Plot.  Gaps in the SASP represent periods when the up-looking radiometer was buried in new snow, before being swept clean immediately after a storm. Albedo values below 0.20 indicate "snow all gone" and represent the albedo of bare soil and tundra. The spike in albedo at SBSP on July 4th mostly likely represents hail.

Radiation instrumentation at each site includes two up-looking, full-range pyranometers (Kipp & Zonen CM21, 305-2800 nm (50% points)), a third filtered pyranometer (Kipp & Zonen™ CM21 with RG695 filter dome, 780-2800 nm (50% points)), and a pyrgeometer (Kipp & Zonen™ CG4). One of the full-range up-looking pyranometers is deployed with a fixed shadow band for measurements of diffuse radiation at solar noon. The shadow post is modeled upon the Swiss's Alpine Surface Radiation Budget project specifications.  On a separate arm, we have two down-looking pyranometers measuring reflected radiation from the snow surface, one full-range (Kipp & Zonen CM21, 305-2800 nm (50% points)) and one filtered (Kipp & Zonen™ CM21 with RG695 filter dome, 780-2800 nm (50% points)).