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Updated: Oct 27, 2025

Surface Renewal: An Advanced Micrometeorological Method for Measuring and Processing Field-Scale Energy Flux Density Data
Published on: December 12, 2013
Gridded daily weather data for North America with comprehensive uncertainty quantification
Peter E Thornton1, Rupesh Shrestha2, Michele Thornton3
1Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA. thorntonpe@ornl.gov.
Daymet V4 provides a 40-year daily gridded weather dataset for North America, enhancing climate and ecological research. This updated version offers improved accuracy and uncertainty quantification for critical meteorological variables.
Area of Science:
- Environmental Science
- Climate Science
- Data Science
Background:
- Daily high-resolution gridded weather data are crucial for ecological, hydrological, and Earth system modeling.
- Existing datasets often lack long-term coverage or sufficient accuracy for detailed studies.
Purpose of the Study:
- To introduce Daymet V4, a 40-year daily meteorological dataset for North America, Hawaii, and Puerto Rico.
- To document methodological improvements enhancing data accuracy and uncertainty quantification.
Main Methods:
- Development of a 1 km gridded daily meteorological dataset using direct observations.
- Implementation of updated algorithms including timing bias reduction, improved 3D regression, and novel handling of high-elevation temperature biases.
- Objective uncertainty quantification via cross-validation analysis for temperature and precipitation.
Main Results:
- Daymet V4 offers daily temperature, precipitation, radiation, vapor pressure, snow water equivalent, and day length for North America, Hawaii, and Puerto Rico.
- Cross-validation demonstrates technical validity and improved accuracy of the new dataset generation methods.
- Quantified uncertainty provides objective measures for temperature and precipitation data.
Conclusions:
- Daymet V4 represents a significant advancement in daily gridded weather data availability and quality.
- The dataset's improvements support more robust scientific research and modeling applications.
- Enhanced data accuracy and uncertainty metrics facilitate reliable use in diverse environmental studies.
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