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Harvard Forest Data Archive


Canopy Phenology, Remote Sensing and Microclimate at Harvard Forest 2006-2011

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  • Lead: Mark Friedl, Nathan Phillips, Manish Verma, Eli Melaas
  • Investigators:
  • Contact: Information Manager
  • Start date: 2006
  • End date: 2011
  • Status: completed
  • Location: Prospect Hill Tract (Harvard Forest)
  • Latitude: +42.537755
  • Longitude: -72.171478
  • Elevation: 340 meter
  • Taxa:
  • Release date: 2011
  • Revisions:
  • EML file: knb-lter-hfr.183.8
  • DOI: digital object identifier
  • EDI: data package
  • DataONE: data package
  • Related links:
  • Study type: long-term measurement
  • Research topic: forest-atmosphere exchange
  • LTER core area: disturbance
  • Keywords: phenology, photosynthetically active radiation, radiation, soil temperature
  • Abstract:

    Our research at the Harvard Forest walk-up tower site examines how seasonality of canopy leaf area, or canopy phenology, influences, and is influenced by, local climate. As part of this activity we are studying methods for (and limits to) remote sensing of canopy phenology. To address this research topic, we have initiated measurements to quantify how radiation fluxes through a deciduous forest canopy are modified by seasonal canopy leaf dynamics. We continuously measure above- and below-canopy radiation fluxes at a variety of spectral bands (shortwave, photosynthetic) and with digital photography. These measurements provide a surrogate measures of canopy leaf area dynamics, and directly represent the radiation component of the surface energy balance. These measurements complement ongoing microclimate and eddy covariance measurements of water and carbon exchange at the EMS flux tower.

  • Methods:

    Photosynthetically active radiation (PAR) is measured using LI190SB LI-COR quantum radiation sensors. A total of five below-canopy sensors measure downwelling PAR below the forest canopy. The sensors are mounted on posts approximately 0.5 meters above the ground surface and are located roughly 20-m from the walk-up tower at equidistant spacing. Above-canopy quantum sensors (upwelling and downwelling) are mounted on a boom extended from the tower at a height of 23-m. Downwelling and upwelling solar radiation measurements are recorded using a Kipp and Zonen thermopile pyranometer, and global (total) and diffuse PAR measurements are measured using a BF3 sunshine sensor (both at 23-m). BF3 sensor photodiodes are cosine corrected and calibrated for the measurement of PAR quanta. Soil temperatures at 20-cm depth are measured with Campbell Scientific 107-L probes in four locations distributed around the walk-up tower and co-located with PAR sensors. Air temperatures are measured using a shaded CS107-L probe at 23-m.

  • Use:

    This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

  • Citation:

    Friedl M, Phillips N, Verma M, Melaas E. 2011. Canopy Phenology, Remote Sensing and Microclimate at Harvard Forest 2006-2011. Harvard Forest Data Archive: HF183 (v.8). Environmental Data Initiative:

Detailed Metadata

hf183-01: radiation data

  1. dataset: dataset ID
  2. datetime: date and time
  3. year: year
  4. doy: day of year (unit: nominalDay / missing value: NA)
  5. hour: hour
  6. toc.d.par: top-of-canopy downwelling PAR (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  7. toc.u.par: top-of-canopy upwelling PAR (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  8. bc.d.par1: below-canopy downwelling PAR 1 (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  9. bc.d.par2: below-canopy downwelling PAR 2 (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  10. bc.d.par3: below-canopy downwelling PAR 3 (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  11. bc.d.par4: below-canopy downwelling PAR 4 (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  12. bc.d.par5: below-canopy downwelling PAR 5 (unit: micromolePerMeterSquaredPerSecond / missing value: NA)
  13. toc.d.pyr: top-of-canopy downwelling Pyranometer (unit: wattPerMeterSquared / missing value: NA)
  14. toc.u.pyr: top-of-canopy upwelling Pyranometer (unit: wattPerMeterSquared / missing value: NA)
  15. tsoil1: soil temperature 1 (unit: celsius / missing value: NA)
  16. tsoil2: soil temperature 2 (unit: celsius / missing value: NA)
  17. tsoil3: soil temperature 3 (unit: celsius / missing value: NA)
  18. tsoil4: soil temperature 4 (unit: celsius / missing value: NA)
  19. tair: air temperature (unit: celsius / missing value: NA)
  20. tsr: total solar radiation (unit: wattPerMeterSquared / missing value: NA)
  21. dsr: diffuse solar radiation (unit: wattPerMeterSquared / missing value: NA)