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NOAA/WDS Paleoclimatology - Meko et al. 2007 Upper Colorado River Flow Reconstruction

browse graphicPaleoclimatology - Climate Reconstruction
This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Climate Reconstruction. The data include parameters of climate reconstructions|tree ring with a geographic location of Colorado, United States Of America. The time period coverage is from 1188 to -55 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data.
  • Cite as: Meko, D.M.; Woodhouse, C.A.; Baisan, C.H.; Knight, T.A.; Lukas, J.J.; Hughes, M.K.; Salzer, M.W. (2007-07-01): NOAA/WDS Paleoclimatology - Meko et al. 2007 Upper Colorado River Flow Reconstruction. [indicate subset used]. NOAA National Centers for Environmental Information. https://doi.org/10.25921/3w6k-2e19. Accessed [date].
  • Please refer to Credit tab for full citation information.
noaa-recon-6387
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Distributor NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Dataset Point of Contact NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Dataset Point of Contact Data Center Contact
NOAA World Data Service for Paleoclimatology
828-271-4800
paleo@noaa.gov
Coverage Description Date Range: 762 CE to 2005 CE; Date Range: 1188 cal yr BP to -55 cal yr BP;
Time Period 762 to 2005
Spatial Bounding Box Coordinates
West: -111
East: -106
South: 37
North: 43
Spatial Coverage Map
General Documentation
Associated Resources
  • Medieval drought in the upper Colorado River Basin.
    • Associated Reference published 2007
      Meko, D.M., C.A. Woodhouse, C.H. Baisan, T. Knight, J.J. Lukas, M.K. Hughes, and M.W. Salzer, 2007: Medieval drought in the upper Colorado River Basin.. Geophysical Research Letters, 34, , 10.1029/2007GL029988
Publication Dates
  • publication: 2007-07-01
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Complete - production of the data has been completed
Data Update Frequency Data update frequency not available
Supplemental Information
STUDY NOTES: Reconstructed annual flows of the Colorado River at Lee Ferry based on new tree-ring records of ring-width from remnant preserved wood. Residual site chronologies were converted to estimates of annual (water-year total) flow of the Colorado River at Lees Ferry(hereafter called "flow") by the following steps. 1) Each chronology was separately converted to an estimate of flow by a lagged regression model. For this model, the predictors were the lags -2 yr to +2 yr on the residual chronology, where the lag is relative to the water year. The predictor was the flow in year t, and the calibration period was the available overlap of the chronology with the 1906-2004 flow data. Predictors were entered stepwise into the regression, with a critical p-value of 0.05 for entry, 0.10 for removal. The lagged model was subjected to split-sample validation to ensure that a statistically significant signal for flow existed in both halves of the the available overlap period. The long-term tree-ring data were substituted into the resulting regression equation to generate a "single-site" reconstruction of flow. Repeating this step for each chronology yielded 11 separate single-site reconstructions of flow, each with time coverage depending on the coverage of the corresponding tree-ring chronology. 2) Single-site reconstructions were grouped into four different subsets depending on time overlap. The common periods of single-site reconstructions in these subsets determined the four reconstruction periods listed in Table 1 in the text. 3) For each of the four subsets of single-site reconstructions, steps 4-6 below were taken to arrive at a single flow reconstruction. This procedure is a weighting of the individual single-site reconstructions. 4) A PCA was run on the single-site reconstructions. The covariance matrix rather than correlation matrix was used in the PCA to retain the influence of the differing variances of the single-site reconstructions. 5) Any PC explaining at least 5 percent of the variance of single-site reconstructions was designated an "important" PC. The PC scores (time series) for the important PCs made up the pool of potential predictors for the next step. 6) Flow was regressed on the PC scores to arrive at a reconstruction of flow for the sub-period. As with the single-site regressions, predictors were entered stepwise into the regression, with a critical p-value of 0.05 for entry, 0.10 for removal. No lags were used in this model, as lagged effects had been handled in the single-site reconstruction. The regression model was cross-validated by successively leaving out 9 values and using the remaining observations to estimated the flow for the central year of the 9-year period. The cross-validation predictions were used to compute the cross-validation root-mean-square error, or RMSE, which is listed in Table 1 in the text. 7) For the entire period of coverage of the tree-ring reconstructions, the flow value from the subset model with the lowest RMSE was substituted as the final reconstructed value. Where reconstructions from more than one model were available, this procedure assigned the reconstruction from the most accurate model as the reconstructed flow. For periods with only one available single-site reconstruction (e.g., the earliest sub-period, or the interval A.D. 762-1181) the final reconstructed flow was necessarily provided by that model regardless of its RMSE. 8) Monte Carlo simulations, following Meko et al. (2001) were used to restore noise to the reconstructed flows and generate an ensemble of realizations of "true" flow as well as place error bars on the annual reconstruction and time averages of the annual reconstruction. Steps 9-10 below summarize the Monte Carlo analysis. 9) 1000 time series of "noise" the same length as the reconstruction were sampled from a normal distribution with mean of zero and standard deviation equal to the RMSE of the reconstruction. The time-varying RMSE (depends on which sub-period model contributed the reconstructed flow for the year) was incorporated in this sampling. In other words, the variance of the noise distribution used to generate the noise-added reconstructed flow for a year was determined by the RMSE of the corresponding reconstruction model. 10) The 1000 noise series were each added to the flow reconstruction from step 7 to get 1000 "noise-added" reconstructions. These are viewed as plausible realizations of flow given the reconstruction and its uncertainty. The 1000 noise-added reconstructions are also an ensemble from which confidence intervals for the unobserved "true" flow can be constructed (e.g., see Figure 2 in text). An 80% confidence interval for 25-year running mean flow was derived by 1) smoothing each of the 1000 noise-added reconstructions with a 25-yearmoving-average filter, 2) Ranking the 1000 smoothed flows in each year, and 3) identifying the 0.10 and 0.90 non-exceedance probabilities of flow from the ranked flows. See also supplementary data files: Supplementary Data 1. Tree ring chronology data and metadata: https://www.ncei.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/meko2007crn.txt Supplementary Data 2. Tree ring measurements data, compressed .zip format https://www.ncei.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/meko2007rwl.zip Note: Full tree ring data series are contained here. Reconstructions were based on shorter subsets meeting minimum sample size criteria. Supplementary Data 3. Reconstruction statistics and references https://www.ncei.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/meko2007stats.txt A version of this file in Microsoft Excel format is also available at: https://www.ncei.noaa.gov/pub/data/paleo/treering/reconstructions/northamerica/usa/upper-colorado-flow2007.xls
ABSTRACT SUPPLIED BY ORIGINATOR: New tree-ring records of ring-width from remnant preserved wood are analyzed to extend the record of reconstructed annual flows of the Colorado River at Lee Ferry into the Medieval Climate Anomaly, when epic droughts are hypothesized from other paleoclimatic evidence to have affected various parts of western North America. The most extreme low-frequency feature of the new reconstruction, covering A.D. 762-2005, is a hydrologic drought in the mid-1100s. The drought is characterized by a decrease of more than 15% in mean annual flow averaged over 25 years, and by the absence of high annual flows over a longer period of about six decades. The drought is consistent in timing with dry conditions inferred from tree-ring data in the Great Basin and Colorado Plateau, but regional differences in intensity emphasize the importance of basin-specific paleoclimatic data in quantifying likely effects of drought on water supply.
Purpose Records of past temperature, precipitation, and other climate variables derived from paleoclimate proxies. Parameter keywords describe what was measured in this data set. Additional summary information can be found in the abstracts of papers listed in the data set citations.
Dataset Citation
  • Cite as: Meko, D.M.; Woodhouse, C.A.; Baisan, C.H.; Knight, T.A.; Lukas, J.J.; Hughes, M.K.; Salzer, M.W. (2007-07-01): NOAA/WDS Paleoclimatology - Meko et al. 2007 Upper Colorado River Flow Reconstruction. [indicate subset used]. NOAA National Centers for Environmental Information. https://doi.org/10.25921/3w6k-2e19. Accessed [date].
  • Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site.
Cited Authors
  • Meko, D.M.
  • Woodhouse, C.A.
  • Baisan, C.H.
  • Knight, T.A.
  • Lukas, J.J.
  • Hughes, M.K.
  • Salzer, M.W.
Originators
  • Meko, D.M.
  • Woodhouse, C.A.
  • Baisan, C.H.
  • Knight, T.A.
  • Lukas, J.J.
  • Hughes, M.K.
  • Salzer, M.W.
Publishers
  • NOAA National Centers for Environmental Information
Theme keywords Global Change Master Directory (GCMD) Science Keywords
  • Earth Science > Climate Indicators > Paleoclimate Indicators > Paleoclimate Reconstructions
Global Change Master Directory (GCMD) Science Keywords
  • earth science > paleoclimate > climate reconstructions|tree ring
  • earth science > paleoclimate > tree ring
  • earth science > paleoclimate > climate reconstructions|tree ring
  • earth science > paleoclimate > climate reconstructions|tree ring
  • earth science > paleoclimate > instrumental
  • earth science > paleoclimate > climate reconstructions|tree ring
  • earth science > paleoclimate > climate reconstructions|tree ring
  • earth science > paleoclimate > instrumental
  • earth science > paleoclimate > tree ring
  • earth science > paleoclimate > climate reconstructions|tree ring
  • earth science > paleoclimate > reconstructions
  • Streamflow Reconstruction
Paleoenvironmental Standard Terms (PaST) Thesaurus
  • What: streamflow; Material: null
  • What: tree ring standardized growth index; Material: null
  • What: notes; Material: null
  • What: streamflow; Material: null
  • What: streamflow; Material: null
  • What: age; Material: null
  • What: streamflow; Material: null
  • What: streamflow; Material: null
  • What: age; Material: null
  • What: streamflow; Material: null
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Place keywords
  • Continent > North America > United States Of America > Colorado > Upper Colorado River Basin > LATITUDE > LONGITUDE
Use Constraints
  • Cite as: Meko, D.M.; Woodhouse, C.A.; Baisan, C.H.; Knight, T.A.; Lukas, J.J.; Hughes, M.K.; Salzer, M.W. (2007-07-01): NOAA/WDS Paleoclimatology - Meko et al. 2007 Upper Colorado River Flow Reconstruction. [indicate subset used]. NOAA National Centers for Environmental Information. https://doi.org/10.25921/3w6k-2e19. Accessed [date].
  • Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
  • Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site.
Access Constraints
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
  • None
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Last Modified: 2023-09-01
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