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Harvard Forest Data Archive

HF440

Column-Averaged Atmospheric Carbon and Water at Harvard Forest since 2018

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Data

Overview

  • Lead: Jonathan Franklin, Steven Wofsy
  • Investigators: John Budney, Bruce Daube, Elaine Gottlieb, William Munger
  • Contact: Information Manager
  • Start date: 2018
  • End date: 2022
  • Status: ongoing
  • Location: Prospect Hill Tract (Harvard Forest)
  • Latitude: +42.533 degrees
  • Longitude: -72.190 degrees
  • Elevation: 340 meter
  • Datum: WGS84
  • Taxa:
  • Release date: 2023
  • Language: English
  • EML file: knb-lter-hfr.440.2
  • DOI: digital object identifier
  • EDI: data package
  • DataONE: data package
  • Related links:
  • Study type: long-term measurement
  • Research topic: forest-atmosphere exchange; regional studies
  • LTER core area: primary production
  • Keywords: atmosphere, carbon, carbon dioxide, climate change, methane, net ecosystem exchange, water
  • Abstract:

    Ground-based total-atmospheric column measurements of CO2, CH4, CO, and H2O began at Harvard Forest in May 2018 using a solar-viewing Fourier Transform Spectrometer (Bruker EM27/Sun). Observations are made from a platform near the Fisher Meteorological Tower throughout the year on sunny days. Total column observations are sensitive to regional carbon fluxes, and are less impacted by changes in the boundary layer height than tower based in-situ observations. The Harvard Forest observations are complemented by an identical instrument operated on the Harvard campus in Cambridge MA. The two sensors are used to support studies of urban emissions, regional transport, and forest-atmosphere exchange. In addition, the total-column measurements provide key validation data for satellite measurements of greenhouse gases.

  • Methods:

    Column-average Dry Mole Fractions were retrieved from near-infrared solar observations collected using a Bruker EM27/Sun Fourier Transform Spectrometer. Spectra gathered by EM27/Sun #46 located near the Fisher Meteorological Tower were processed using the 2020 version of GGG created by Geoffrey Toon. EGI2020 was used to create inputs for GGG and automate the retrieval process. Details on GGG and EGI are available at https://tccon-wiki.caltech.edu.

    Column abundances of CO2, H2O, CH4, CO, and O2 were retrieved. The O2 retrieval is used to convert all others into DMFs. For example, dry column-average CO2 DMF has been calculated according to CO2 DMF = 0.2095 x column CO2 / column O2.

    Spectra are gathered every ~11 seconds, and are then averaged into 15 minute bins.

  • Organization: Harvard Forest. 324 North Main Street, Petersham, MA 01366, USA. Phone (978) 724-3302. Fax (978) 724-3595.

  • Project: The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. (ROR).

  • Funding: National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210. Other funding: NASA grant 80NSSC21K1069.

  • 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.

  • License: Creative Commons Zero v1.0 Universal (CC0-1.0)

  • Citation: Franklin J, Wofsy S. 2023. Column-Averaged Atmospheric Carbon and Water at Harvard Forest since 2018. Harvard Forest Data Archive: HF440 (v.2). Environmental Data Initiative: https://doi.org/10.6073/pasta/d05e2b0fad02abd0a5ca3f9aa990e281.

Detailed Metadata

hf440-01: atmospheric carbon and water data

  1. datetime: date and time of measurement
  2. xco2_ppm: column-averaged dry mole fraction of carbon dioxide, parts per million (unit: dimensionless / missing value: NA)
  3. xch4_ppb: column-averaged dry mole fraction of methane, parts per billion (unit: dimensionless / missing value: NA)
  4. xco_ppb: column-averaged dry mole fraction of carbon monoxide, parts per billion (unit: dimensionless / missing value: NA)
  5. xh2o_ppm: column-averaged dry mole fraction of water, parts per million (unit: dimensionless / missing value: NA)