uid=AND,o=lter,dc=ecoinformatics,dc=org all public read MS029 Theresa J. Valentine

USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way Corvallis OR 97331 USA

(541) 750-7333 theresa.valentine56@gmail.com Christopher Daly

PRISM Group;Northwest Alliance for Computational Science and Engineering, 2000 Kelley Engineering Center;Oregon State University Corvallis OR 97331 USA

(541) 737-2531 daly@nacse.org http://prism.oregonstate.edu Principal Investigator Christopher Daly

PRISM Group;Northwest Alliance for Computational Science and Engineering, 2000 Kelley Engineering Center;Oregon State University Corvallis OR 97331 USA

(541) 737-2531 daly@nacse.org http://prism.oregonstate.edu Tool Contact Theresa J. Valentine

USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way Corvallis OR 97331 USA

(541) 750-7333 theresa.valentine56@gmail.com Distributor Theresa J. Valentine

USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way Corvallis OR 97331 USA

(541) 750-7333 theresa.valentine56@gmail.com Abstractor Jonathan W. Smith

Oregon State University;Oregon Climate Service;316 Straud Ag Hall Corvallis OR 97331 USA

mumidec@yahoo.com Other Researcher 2015-12-07 Mean monthly maximum and minimum air temperature spatial grids (1971-2000), adjusted for the effects of solar radiation and sky view factors, Andrews Experimental Forest. Maps were created using PRISM (Parameter-elevation Regressions on Independent Slopes Model), developed by Dr. Christopher Daly at Oregon State University’s PRISM Climate Group in 2010 (prism.oregonstate.edu). Grids were exported into ASCII format from GRASS GIS software; values are in degrees C x 100. Spatial resolution is 50 meters. Two sets of temperature values are available: (1) values derived from an interpolation of point station temperature values accounting for elevation; and (2) values from (1), adjusted for effects of solar radiation exposure and sky view factors. Radiation exposure and sky view factors were calculated from a two-stream solar radiation model that accounts for elevation, slope, aspect, and shading from adjacent pixels on a 50-m digital elevation model. Temperature data were obtained from selected benchmark and reference stand climate stations within the HJ Andrews, as well as National Weather Service Cooperative (COOP) and USDA NRCS Snow Telemetry (SNOTEL) stations in the vicinity. Due to the sparseness of the station data outside the Andrews, values outside the Andrews are considered to have high uncertainty. Temperature values assume an open site with no canopy cover, so are not appropriate for describing temperatures within the forest canopy. See MS033 for radiation grids used to make the radiation adjustments. meteorology climatology climate air temperature mapping disturbance modeling LTER controlled vocabulary disturbance LTER core research areas Related PublicationsSmith, Jonathan W. 2002. Mapping the thermal climate of the H.J. Andrews Experimental Forest, Oregon. Corvallis, OR: Oregon State University. 222 p. M.S. thesis. Data Use Agreement: The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. This Data Set is released under the Creative Commons license CC BY "Attribution" (see: https://creativecommons.org/licenses/by/4.0/). Creative Commons license CC BY - Attribution is a license that allows others to distribute, remix, tweak, and build upon your work (even commercially), as long as you are credited for the original creation. This license accommodates maximum dissemination and use of licensed materials. It is considered professional conduct and an ethical obligation to acknowledge the work of other scientists. The Data User is asked to provide attribution of the original work if this data package is shared in whole or by individual parts or used in the derivation of other products. A recommended citation is provided for each Data Set in the Andrews LTER data catalog (see: http://andlter.forestry.oregonstate.edu/data/catalog/datacatalog.aspx). A generic citation is also provided for this Data Set on the website https://portal.edirepository.org in the summary metadata page. Data Users are thus strongly encouraged to consider consultation, collaboration and/or co-authorship with the Data Set Creator. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed and all data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. General acknowledgement: Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB 2025755), US Forest Service Pacific Northwest Research Station, and Oregon State University. http://andlter.forestry.oregonstate.edu/data/abstract.aspx?dbcode=MS029 Andrews Experimental Forest within the Willamette National Forest, western Cascades, Oregon, USA -122.29238000 122.05894500 44.29723500 44.16548100 1971-01-01 2000-12-31 Dataset was created to provide a high-quality, baseline description of 30-year monthly average temperature "normals" over the HJ Andrews Forest and vicinity, accounting for terrain-based solar radiation exposure. Temperature values assume an open site with no canopy cover, so are not appropriate for describing temperatures within the forest canopy.

An update history is logged and maintained with each new version of every dataset.

notPlanned GIS coverage creation date. Version1 2002-02-07 Metadata files created in ARC/catalog as HTML format. ARC/Info Export files, shape files, or other data file on ftp.fsl.orst.edu. Version2 2004-11-03 Upper level gis metadata (catalog, databases, entity, sub_entity, catalog_component, cross_reference, update_history) restructured and moved into SQLServer metadata database LTERMETA. Version3 2005-06-15 data was projected to NAD83 and moved into PASTA Version5 2015-12-07 Information Manager

Andrews Forest LTER Program US Forest Service Pacific Northwest Research Station 3200 SW Jefferson Way Corvallis OR 97331

hjaweb@fsl.orst.edu http://andrewsforest.oregonstate.edu/ Theresa J. Valentine

USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way Corvallis OR 97331 USA

(541) 750-7333 theresa.valentine56@gmail.com Andrews Forest LTER Site

Forest Ecosystems and Society Department in Forestry Oregon State University 201K Richardson Hall Corvallis OR 97331-5752

(541) 737-8480 lterweb@fsl.orst.edu http://andrewsforest.oregonstate.edu/ <para>Processing Procedures - MS029</para><para>Original datasets consisted of daily mean, maximum and minimum temperatures that had been quality-checked and processed into a consistent format. Missing data were indicated and questionable values were flagged according to a number of conditions (Bierlmaier, pers. comm.) Any value flagged in any way during this first filtering process was immediately discarded from the database and transformed into a missing value for that day. Daily temperatures were graphed and visually analyzed again on monthly and yearly scales to check for erroneous values possibly missed during the first filtering process. Again, any questionable values were discarded, ensuring the most reliable possible dataset. For the MET sites with variable sensor heights, the 1.5 meter values were used unless that value was missing, in which case the next lower sensor (2.5 meters) was used.<para> <para>After filtering twice, any site left with less than three years of data (10% of the 30-year period) was discarded. The GR sites were an exception to this rule because of their strategic locations in underrepresented areas or next to open MET sites (making them ideal for open/closed canopy comparisons). Most discarded sites are in areas that are adequately represented spatially by long-term sites.</para> <para>After mean monthly maximum and minimum temperature datasets were adjusted with regression functions to simulate open flat sites, they were imported into PRISM. PRISM uses a combination of geographic and statistical methods to spatially interpolate climate variables (Daly et al., 1994). It is a coordinated set of rules, decisions, and calculations (an ‘inference engine’) designed to mirror the decision-making process an expert climatologist would use in making a map (Daly and Johnson, 1999).</para> <para>Weights are assigned to the point data according to various factors. A station is downweighted when its elevation differs significantly from that of the target cell or is far from it geographically. The station’s influence is further reduced if it is clustered with others (avoiding over-representation), or has a significantly different slope and aspect (topographic facet) than the target cell (Daly et al., 1997). When used on large areas, PRISM is able to consider a station’s proximity to the ocean and the ‘flatness’ of an area to determine whether two-dimensional or three-dimensional estimates should be used (Daly and Johnson, 1999). These last two factors are not important in this study, because the HJA is a small area 150 kilometers from the nearest ocean and is hilly enough to require only the three-dimensional model.</para> <para>An iterative approach was taken in creating the gridded data for the temperature maps. With the exception of the stream sites, all canopy/topography-adjusted maximum and minimum temperature datasets were initially input into PRISM, using default parameters and a single-layer atmosphere model. The resulting grids clearly showed which sites to initially discard. For example, the unusually warm sites RS38, RS89, and H15MET were visually obvious as high temperature ‘bulls eyes’. All GR sites were revealed to be anomalously warm and were also discarded. Other sites such as CS2MET, RS02 and RS86 were also discarded because of warm or cold spatial biases. Including RS01’s data caused unusual temperature patterns due to the seasonal presence of Blue River Reservoir. From initial PRISM modeling and personal experience, VANMET was known to be anomalously warm and RS04 anomalously cool. In order to retain spatial representation in their area, a ‘pseudo-site’ was created at point between them on the DEM, with temperature values given as their averages for each month. Using this pseudo-site instead of VANMET and RS04 individually gave far more realistic temperatures on top of the northern peaks and ridges of the HJA. The National Climatic Data Center’s 500-millibar (approximately 5200 meters) 2.5° global temperature grid was used as a high-level anchor ‘site’ over the HJA to ensure that the tops of the highest peaks and ridges in the area were modeled correctly. Table 4.26 summarizes the sites used in the final analysis. With the exception of the Mack Creek area, most regions within the HJA are fairly well-represented spatially, having a measurement station within about two kilometers.</para> <para>PRISM was run again with the reduced set of sites. Since the number of sites had been decreased to 15, the radius of influence was specified to consider every point in the HJA when making cell estimates. Even using a single atmospheric layer model with this specification, a temperature inversion over the lower Lookout Creek Valley was evident during most months for both maximum and minimum temperatures. The maximum temperature inversion is more defined in January (at an elevation of approximately 700 meters), with minimum temperature inversions well-defined in both January and July at approximately 720 meters. Taking the base elevation of the Lookout Creek valley to be 420 meters, depths of inversions over it were approximately 280 meters for maximum temperatures and 300 meters for minimum temperatures.</para> <para>We thus switched to the two-atmosphere model in PRISM with these inversion height values specified. A certain amount of ‘cross-talk’ was allowed between layers to avoid an unnaturally abrupt transition between layers. Elevations were buffered by ± 150 meters for maximum temperature and ± 120 meters for minimum temperatures, reflecting the higher seasonal variation in minimum temperature inversion heights. Variable inversion heights with elevation were modeled such that the deepest inversions were found at the lowest elevations (over the lower Lookout Creek and McKenzie River valleys). The two-layer atmosphere model was used to model both maximum and minimum temperatures for every month.</para> <para>All of the final parameter values used to make the grids were determined by varying them slightly in different combinations, then iteratively running PRISM and analyzing the results both statistically (with regression functions through the PRISM interface) or visually (with the temperature grids). In this way, knowledge of HJA microclimatology could be applied and combined with PRISM’s statistical abilities to create maps that were not only numerically sound, but made sense physically. </para> Caution must be taken when using estimated temperatures for areas outside the HJA boundaries shown in the maps. This is because environmental processes within the Lookout Creek watershed were used to quantify the effects of elevation, canopy, cloudiness, and topography on temperatures, and these effects were extrapolated to other areas, where in fact environmental processes may affect temperatures differently. Because adjustments may have obscured sensitive long-term trends in the datasets, caution should also be taken when using the final dataset to investigate evidence of long-term climatic events in the HJA, such as those associated with PDO (Pacific Decadal Oscillation) or ENSO (El Nino/Southern Oscillation) phenomena. <para>In any research project that bases its methodology on hypothesized quantifications of natural phenomena, there can be many sources of uncertainty. In this project, errors were not additive throughout the process because of the way in which the methodology was conducted (for example, the selective elimination of sites from the analysis at certain stages). Thus, the potential sources of error must be examined at each step independently of one another. Though a formal error analysis could not be done because of low confidence in the historical dataset as a whole, the following discussion attempts to quantify potential sources of uncertainty.</para> Historical temperature data at the HJA have been gathered using partially shielded mercury bulb thermometers and thermisters. Instrumentation error for mercury thermometers (used for about two-thirds of the total period of record) was approximately ± 2.0°C, with another ± 2.0°C error introduced when digitizing the paper charts. Thermisters, installed by the early 1990s at all sites, are accurate to approximately ± 0.4°C (J. Moreau, pers. comm.). The inconsistency of sensor heights above the ground may also have been a source of error, though probably a small one. Mean monthly temperatures were less likely to have been affected by these observational errors than the original daily datasets. <para>Mean monthly temperatures at sites with short records were adjusted to the full 30-year period using the highest correlated long-term site. For maximum temperature adjustments, mean absolute errors for periods of record ranged from 1.1°C for a one-year period of record to 0.2°C for a 24-year period of record (0.6°C to 0.2°C for minimum temperatures). The shorter the period of record for a short-term site, the greater the error, but potential temperature errors never exceeded 0.7°C because any site with less than three years of original data was not considered (mean absolute errors for maximum and minimum temperatures were 0.7°C to 0.6°C for three-year periods of record, respectively). Thus, errors introduced into the procedure by temporal adjustments were likely minimal compared to observational errors.</para> Error estimates of the temperature interpolation process were made using a jackknife cross-validation procedure within PRISM. At each station location, PRISM was run without that station to estimate the temperature at its location, and the predicted values were compared to the observed station value. Mean absolute errors, which are the average of the absolute value of error, ranged from 0.5°C to 0.9°C for maximum temperatures, and from 0.1°C to 0.3°C for minimum temperatures throughout the year. Biases, which assess how high or low estimates are across the entire grid, ranged from +0.1°C to +0.3°C for maximum temperatures, and from 0.0°C to +0.1°C for minimum temperatures. All of these values are well within observational error, and show that spatial interpolation of temperatures introduced low levels of uncertainty to the process. <para>There were other possible sources of error in the original temperature datasets. Forest edges (boundary areas between clearings and forests) and streams probably affected long-term monthly temperature values. Many climate stations in the HJA have been and are located within distances that may be affected by edges and streams. These physical features could not be accounted for in this study because necessary datasets did not exist to quantify them. This study also did not quantify scale-dependent temperature advection processes that may affect temperatures in the HJA. For example, temperature regimes on an even, broad north-facing slope are likely different than those on a small north-facing slope having several slopes of varying orientation nearby. </para> Sherri L. Johnson

US Forest Service ;Pacific NW Research Station ;3200 SW Jefferson Way Corvallis OR 97331 USA

541-758-7771 sherri.johnson2@usda.gov sherri.johnson@oregonstate.edu https://www.fs.fed.us/research/people/profile.php?alias=sherrijohnson Principal Investigator Julia A. Jones

Oregon State University;Department of Geosciences; Wilkinson Hall 104 Corvallis OR 97331-5506 USA

(541) 737-1224 Julia.Jones@oregonstate.edu geojulia@comcast.net http://ceoas.oregonstate.edu/profile/jones/ http://orcid.org/0000-0001-9429-8925 Principal Investigator Matthew G Betts

Department of Forest Ecosystems and Society; 201E Richardson Hall; College of Forestry; Oregon State University Corvallis OR 97331

(541) 737-3841 matt.betts@oregonstate.edu http://www.fsl.orst.edu/flel/index.htm Principal Investigator Michael P. Nelson

Department of Forest Ecosystems and Society; 201K Richarson Hall; College of Forestry; Oregon State University Corvallis OR 97331

541-737-9221 mpnelson@oregonstate.edu http://www.michaelpnelson.com http://orcid.org/0000-0001-6917-4752 Principal Investigator David Bell david.bell@usda.gov david.bell@oregonstate.edu https://lemma.forestry.oregonstate.edu/about/david-bell Principal Investigator The H.J. Andrews Experimental Forest is a living laboratory that provides unparalleled opportunities for the study of forest and stream ecosystems in the central Cascade Range of Oregon. Since 1980, as a part of the National Science Foundation Long Term Ecological Research (NSF-LTER) program, the Andrews Experimental Forest has become a leader in the analysis of forest and stream ecosystem dynamics. Long-term field experiments and measurement programs have focused on climate dynamics, streamflow, water quality, and vegetation succession. Currently researchers are working to develop concepts and tools needed to predict effects of natural disturbance, land use, and climate change on ecosystem structure, function, and species composition. The Andrews Experimental Forest is administered cooperatively by the USDA Forest Service Pacific Northwest Research Station, Oregon State University and the Willamette National Forest. Funding for the research program comes from the National Science Foundation (NSF), US Forest Service Pacific Northwest Research Station, Oregon State University, and other sources. Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB 2025755), US Forest Service Pacific Northwest Research Station, and Oregon State University. National Science Foundation: DEB1440409 The Andrews Forest is situated in the western Cascade Range of Oregon, and covers the entire 15,800-acre (6400-ha) drainage basin of Lookout Creek. Elevation ranges from 1350 to 5340 feet (410 to 1630 m). Broadly representative of the rugged mountainous landscape of the Pacific Northwest, the Andrews Forest contains excellent examples of the region's conifer forests and associated wildlife and stream ecosystems. These forests are among the tallest and most productive in the world, with tree heights of often greater than 250 ft (75 m). Streams are steep, cold and clean, providing habitat for numerous aquatic organisms.