A plurality of contemporary hydrologists, paleo earth scientists, marine scientists, atmospheric scientists, and climate scientists appear to routinely and consistently assert that the planet is warming exclusively due to anthropogenic emissions, and that this warming is leading to both global ocean acidification and to earlier peak streamflow runoff  (the Early Spring) somewhat localized to the Western United States.

This post is part of a line of discussion of the so called Early Spring (ES) notion.  For one of many examples which provide an apparent foundation to the ES, I have examined the 2nd Edition of  “Climate Change in Colorado.   A Report for the Colorado Water Conservation Board Western Water Assessment, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder” is co-authored and/or peer reviewed by over 40 scientists [1].

In its Executive Summary the report states that: The timing of snowmelt and peak runoff has shifted earlier in the spring by 1–4 weeks across Colorado’s river basins over the past 30 years, due to the combination of lower SWE since 2000, the warming trend in spring temperatures, and enhanced solar absorption from dust-on-snow.

I may have missed something but following my search of the full report and a follow up discussion with two of the primary authors, I could not find any documentation to support that quote.  In any case it is straightforward for me as a stochastic hydrologist to explore this  assertion and to reduce it to simple reproducible experiments.  The featured image accordingly is intended to capture the exploration of a peak flow for a representative stream in the western United States.  In this instance the focus is on the monthly average record for the Animas River at Farmington, New Mexico, whose headwaters reach deeply into the highest peaks of the San Juan range of the Southern Rocky Mountains of the western US within Colorado.

I often focus my attention on the Animas River, if only because of its relation to sunspot numbers, I have recently completed an Animas paper for a related conference proceeding sponsored by the New Mexico Water Resources Research Institute (WRRI) based at New Mexico State University at Las Cruces, NM.

In that work I’ve already presented, I’ve run an array of hydrostatistical and performance measures to the time series records, both measured and modeled, of that and related streams.  Here in the featured image I have chosen in part to unroll the specific Animas monthly streamflow data and use Microsoft Excel’s cell color ranking formatting features to quickly detail the deep-green band.  Only that band traces through each month of peak flow.  I’ve added a supporting chart within that image which identifies the peak flow month in a more conventional mode.

The apparent conclusion must be that across this basin there is little or no evidence of a descent of the peak flow month for the full complete available history of the stream.  This result supports an alternate argument that there is no evidence of an earlier spring than normal.

Moreover, there are now excellent arguments that the hydrologic runoff is strongly and significantly correlated across most if not all seasons and years to well mapped ocean indexes.  The next image replicates related items that I and others have explored for approximately the past decade or so.  In this chart the actual (versus “peak rank” of the previous image) Animas flows are simply compared to the Pacific Decadal Oscillation (PDO) over an available continuous Animas record span dating back to the first half of the 20th century.

The Animas and its neighbor basins cannot be highly correlated to both the PDO and to an early spring.  I have explored this further in the next attachment, where I have overlayed the Animas and PDO time series across one of that author’s plots [2] of a time series of snow water equivalents (SWE) values from multiple SNOTEL sites across a similar study area to mine:

AnimasVsClowbyMWallace2018a

It would not be a surprise to many hydrologists that the relative peaks and dips are fairly synchronous.  This is excellent independent confirmation I feel of the SNOTEL values but is only an informal part of an informal exercise.

I don’t mind repeating that the attachment appears to demonstrate that the Animas example and others are consistent with the SWE outcome.   However that and other papers covering the SWE outcome, and which also assert an early spring, do not incorporate the PDO.  It accordingly may be that the early spring notion largely predates more widespread recognition of the influence of the PDO.  On the other hand, if the authors were aware of the PDO connection and failed to note it or if they simply marginalized it [1, 2], that is a concern.  I certainly appeal to all of those to reconsider how this issue is approached.

In any case, I expect that early spring notions will soon be eclipsed as understanding grows regarding the failure of the observations to support the Early Spring assertions, as well as the many demonstrations at this site which point to more accurate ocean and solar based forecasts of streamflows in the Western US, including of course, the Animas River.

In a future set of posts I will expand from the Animas diagrams shown to produce similar graphs for a wider range of streams.  I have already worked to compile many of these, including for example, Twin River near Round Mountain, Nevada, the North Fork of the Big Lost River near Chilly, Idaho, Big Bear Creek near the Utah – Wyoming Border, and Clear Creek near Lawson Colorado, and a variety of others.  All continue to confirm the complete absence of any indication of the Early Spring.

In another set of posts, I plan to document my exploration the VIC output charts developed recently by the West Wide Climate Assessment that relate to the Early Spring theme that is featured here.  The reproducibility (or its deficiency) of data both observed or simulated, to the charts will be closely examined.

 

[1]  The authors and reviewers for the report “Climate Change in Colorado.   A Report for the Colorado Water Conservation Board Western Water Assessment, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder”:

http://wwa.colorado.edu/climate/co2014report/Climate_Change_CO_Report_2014_FINAL.pdf

Lead Author
Jeff Lukas, University of Colorado Boulder, CIRES Western Water Assessment

Authors

Joseph Barsugli, University of Colorado Boulder, CIRES
Nolan Doesken, Colorado State University, Colorado Climate Center
Imtiaz Rangwala, University of Colorado Boulder, CIRES Western Water Assessment
Klaus Wolter, University of Colorado Boulder, CIRES

Other Contributors

Ray Alvarado, Colorado Water Conservation Board
Jeff Arnold, U.S. Army Corps of Engineers
Kristen Averyt, University of Colorado Boulder, CIRES Western Water Assessment
Tim Bardsley, University of Colorado Boulder, CIRES Western Water Assessment
Leon Basdekas, Colorado Springs Utilities
Levi Brekke, Bureau of Reclamation
David Clow, U.S. Geological Survey
Gerald (Jay) Day, Riverside Technology
Karin Decker, Colorado Natural Heritage Program
Jeffrey Deems, University of Colorado Boulder, CIRES
Lisa Dilling, University of Colorado Boulder, CIRES
Tom Easley, Rocky Mountain Climate Organization
Taryn Finnessey, Colorado Water Conservation Board
Subhrendu Gangopadhyay, Bureau of Reclamation
Andrew Gilmore, Bureau of Reclamation
Eric Gordon, University of Colorado Boulder, CIRES Western Water Assessment
Ben Harding, AMEC Environment & Infrastructure
Martin Hoerling, NOAA ESRL Physical Science Division
Barb Horn, Colorado Parks & Wildlife
Laurna Kaatz, Denver Water
Eric Kuhn, Colorado River District
Ben Livneh, University of Colorado Boulder, CIRES
Elizabeth (Bets) McNie, University of Colorado Boulder, CIRES Western Water Assessment
Katie Melander, Northern Water
Paul Miller, NOAA NWS Colorado Basin River Forecast Center
Noah Molotch, University of Colorado Boulder, Geography Dept. and INSTAAR
Roger Pielke, Sr., University of Colorado Boulder, CIRES
Andy Pineda, Northern Water
James Prairie, Bureau of Reclamation
Roy Rasmussen, National Center for Atmospheric Research
Andrea Ray, NOAA ESRL Physical Science Division
Ana Ruiz, City of Thornton
Wendy Ryan, Colorado State University, Colorado Climate Center
John Sanderson, The Nature Conservancy
Stephen Saunders, Rocky Mountain Climate Organization
Joel Smith, Stratus Consulting
Robert Steger, Denver Water
Michelle Stokes, NOAA NWS Colorado Basin River Forecast Center
Stacy Tellinghuisen, Western Resource Advocates
Marc Waage, Denver Water
Andy Wood, National Center for Atmospheric Research

 

 

[2] Clow, D. W. 2010. Changes in the timing of snowmelt and streamflow in Colorado: A response to recent warming. Journal of Climate 23(9): 2293-2306.

https://co.water.usgs.gov/publications/non-usgs/Clow2010_SnowmeltTiming.pdf