MS029: Mean monthly maximum and minimum air temperature spatial grids (1971-2000), Andrews Experimental Forest
Notice
"As Is" Basis: All content, including maps and forecasts, is provided without warranties. Users are advised to independently verify critical information.
Citation
2015. Mean monthly maximum and minimum air temperature spatial grids (1971-2000), Andrews Experimental Forest Long-Term Ecological Research Andrews Forest LTER Site. [Database]. Available: https://andrewsforest-stage.forestry.oregonstate.edu/data/fsdb-data-catalog/MS029 Accessed 2026-05-10.
Abstract
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.
Coverage
Temporal coverage: 1971-01-01 to 2000-12-31
Geographic coverage: Andrews Experimental Forest within the Willamette National Forest, western Cascades, Oregon, USA
Spatial coverage:
Bounds: W -122.29238000, E 122.05894500, N 44.29723500, S 44.16548100
Purpose
- 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.
Project
Title: Long-Term Ecological Research
Personnel
-
Sherri L. Johnson - Principal Investigator US Forest Service ;Pacific NW Research Station ;3200 SW Jefferson Way, Corvallis, OR, 97331, USAPhone: 541-758-7771Email: sherri.johnson2@usda.gov, sherri.johnson@oregonstate.edu
-
Julia A. Jones - Principal Investigator Oregon State University;Department of Geosciences; Wilkinson Hall 104, Corvallis, OR, 97331-5506, USAPhone: (541) 737-1224Email: Julia.Jones@oregonstate.edu, geojulia@comcast.netORCID: http://orcid.org/0000-0001-9429-8925
-
Matthew G Betts - Principal Investigator Department of Forest Ecosystems and Society; 201E Richardson Hall; College of Forestry; Oregon State University, Corvallis, OR, 97331Phone: (541) 737-3841Email: matt.betts@oregonstate.edu
-
Michael P. Nelson - Principal Investigator Department of Forest Ecosystems and Society; 201K Richarson Hall; College of Forestry; Oregon State University, Corvallis, OR, 97331Phone: 541-737-9221Email: mpnelson@oregonstate.eduORCID: http://orcid.org/0000-0001-6917-4752
-
David Bell - Principal Investigator Email: david.bell@usda.gov, david.bell@oregonstate.edu
Abstract
- 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.
Funding
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
Study Area Description
-
Long-Term Ecological Research 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.
Associated Party
-
Christopher Daly
Role: Principal InvestigatorPRISM Group;Northwest Alliance for Computational Science and Engineering, 2000 Kelley Engineering Center;Oregon State University, Corvallis, OR, 97331, USAPhone: (541) 737-2531Email: daly@nacse.org
-
Christopher Daly
Role: Tool ContactPRISM Group;Northwest Alliance for Computational Science and Engineering, 2000 Kelley Engineering Center;Oregon State University, Corvallis, OR, 97331, USAPhone: (541) 737-2531Email: daly@nacse.org
-
Theresa J. Valentine
Role: DistributorUSDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way, Corvallis, OR, 97331, USAPhone: (541) 750-7333Email: theresa.valentine56@gmail.com
-
Theresa J. Valentine
Role: AbstractorUSDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way, Corvallis, OR, 97331, USAPhone: (541) 750-7333Email: theresa.valentine56@gmail.com
-
Jonathan W. Smith
Role: Other ResearcherOregon State University;Oregon Climate Service;316 Straud Ag Hall, Corvallis, OR, 97331, USAEmail: mumidec@yahoo.com
Contact
-
Information Manager
Andrews Forest LTER Program, US Forest Service Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR, 97331Email: hjaweb@fsl.orst.edu
-
Theresa J. Valentine
USDA Forest Service;Pacific NW Research Station;3200 SW Jefferson Way, Corvallis, OR, 97331, USAPhone: (541) 750-7333Email: theresa.valentine56@gmail.com
Publisher
-
Andrews Forest LTER Site
Role: PublisherForest Ecosystems and Society Department in Forestry, Oregon State University, 201K Richardson Hall, Corvallis, OR, 97331-5752Phone: (541) 737-8480Email: lterweb@fsl.orst.edu
Study Description
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. 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.
Purpose: 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.
Methods
Method Steps
Method Step 1
No method step description paragraphs listed.
Instrumentation:
- 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>
Sampling
Software
No software entries listed in this EML file.
Keywords
- LTER controlled vocabulary: meteorology (theme), climatology (theme), climate (theme), air temperature (theme), mapping (theme), disturbance (theme), modeling (theme)
- LTER core research areas: disturbance (theme)
Taxonomic Hierarchy
No taxonomic hierarchy listed in this EML file.
Data Entities
No data tables listed in this EML file.
Metadata
No data tables listed in this EML file.
Units
No units listed in this EML file.
Intellectual Rights
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.
Licensed
License: N/A
Maintenance
Maintenance update frequency: notPlanned
Description
- An update history is logged and maintained with each new version of every dataset.
Change History
-
Version1 (2002-02-07) GIS coverage creation date.
-
Version2 (2004-11-03) Metadata files created in ARC/catalog as HTML format. ARC/Info Export files, shape files, or other data file on ftp.fsl.orst.edu.
-
Version3 (2005-06-15) Upper level gis metadata (catalog, databases, entity, sub_entity, catalog_component, cross_reference, update_history) restructured and moved into SQLServer metadata database LTERMETA.
-
Version5 (2015-12-07) data was projected to NAD83 and moved into PASTA