Oct 17 2018


Increase the Value of Your Observations

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Brad Withrow-Robinson, OSU Forestry and Natural Resources Extension agent for Benton, Linn and Polk Counties.

The retreat was a great opportunity for OST volunteers to see how their observations at home, woodland or school yard contribute to work being done at the Andrews forest and elsewhere. The take home message, heard from several of the speakers (including Chris Daly and Mark Schulze) was that your observations matter!

Chris Daly (see previous Meet the Partner article) explained the challenges, complexity and equipment needed to measure precipitation at high elevations of the Andrews.  He described some of the findings about air movement and pooling in a complex mountain environment the observations collected at the Andrews have led to.

A look at annual precipitation patterns across the topography of HJA.

Chris repeatedly returned to the importance of citizen science data from the CoCoRaHS system in supplementing and building out a much broader network of observation points than could be done as part of research programs such as his. “I had no idea researchers relied on citizen science data as much as they do.”  said one Season Tracker.

Chris Daly, founder and director of OSU PRISM Climate Group, talking with OST volunteers. (photo by Victor Villegas)

But in explaining how CoCoRaHS data are used in his and other forecasting models, he clarified the value of some different reporting options that will lead to some changes in future OST trainings.

We have always stressed the importance of recording zeros when there is no precipitation.  There is a very important difference between a zero and no report.  Zero means no precipitation fell.  No report is missing data: an unknown, with no predictive value.  Thus the importance of reporting even when there is no precipitation.

But we have also promoted (and used) the convenience of reporting all those zeros during the long dull summer, on a weekly or even monthly basis (“monthly zeros”).  This has implications we overlooked, and will no longer be encouraged in OST trainings.  Here is why: our CoCoRaHS data have different uses according to their freshness.  Fresh data, submitted every day before 9 AM has the greatest range of uses, the greatest value. That is because consumers of CoCoRaHS data like PRISM, the National Weather Service and others download those data daily for their models.  When data (zeros or otherwise) are submitted days later, they have already been left out of many short term uses.  They have become “stale” and have lost much of their potential value.   Also, frequent delays or gaps in reporting at a site in any month (a type of under-reporting) will cause that month’s data to be flagged or removed from certain data sets, to avoid skewing the predations.  Further reducing the impact.

So, reporting all those zeros in batches is useful to the long term data set and does provide long term, scientific value.  But waiting days or weeks to report zeros in batches, rather than daily before 9 AM, can significantly reduce the applications and value of your observations.  This message was clearly heard by volunteers in attendance who, when asked if and how the retreat might change their behavior reported “ Yes, more daily measurements of rainfall – send in 0’s”.  “Yes, I will continue my OST activities with even more enthusiasm” and “Keep up DAILY loggings of rain/snow levels.”

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