Surface flux and micrometeorological measurements were collected at one site within the northwest quadrant near the center of the FIFE study area during all five of the Intensive Field Campaigns (four in 1987 and one in 1989). This site had historically been ungrazed but had recently been exposed to grazing. The station was capable of measuring the fluxes of net radiation, sensible heat and latent heat using an eddy correlation system. In addition, measurements of soil heat flux and several micrometeorological parameters were made.

The Eddy Correlations Surface Flux Observations (GSFC) Data Set contains surface flux measurements made at selected sites within the FIFE study area. The surface flux and micrometeorological measurements in this data set were collected from a single location located in the southwest quadrant on a upland, grazed area. The data set contains data collected daily from June 26 - October 17, 1987 during the three Intensive Field Campaigns. No data is available between the campaigns. Micrometeorological techniques of eddy correlation and Bowen ratio were used in determining the fluxes of sensible heat, latent heat, and carbon dioxide in FIFE. Eddy correlation is a well-established technique that has the primary advantage of measuring turbulent diffusive fluxes directly across a near-horizontal plane above the surface. It requires a rigid platform unencumbered by significant aerodynamic obstacles. The fluxes of sensible and latent heat are computed as covariances of the fluctuations of vertical wind velocity with fluctuations of temperature and vapor density at the same point and time.

Surface flux measurements were made at selected sites within the FIFE study area. Each surface flux station was capable of measuring the fluxes of net radiation, sensible heat, and latent heat. The Eddy Correlation Surface Flux Observations (UK) Data Set contains surface flux and micrometeorological measurements collected from one location in the southwest quadrant of the FIFE study area. This location was grazed and had a gentle downhill slope to the southwest. Data were collected daily from May 14 - October 18, 1987, and from July 21 - August 16, 1989. The output from the Hydra sensors is sampled at 10 Hz and processed in real time to give hourly averages of sensible and latent heat flux and the friction velocity. The hourly mean values of net radiation, temperature, and of vapor pressure, provided in this data are a synthesis of the best measurements available for this site. The temperature measurement provided here is the preferred value for this site. This temperature was used to calculate the fluxes and some standard deviations. This is necessary because the sonic anemometer has a slightly temperature dependent calibration. The average soil heat flux measured at 5 mm depth is a weighted average value over three sample positions with dense, medium and sparse vegetation. A vegetation survey was made to assign weights to these three classes at this site. The spatial variability in this measurement at this (over) grazed site is particularly high and the three individual sensors commonly measure soil heat fluxes differing by factors of two or three. Some evidence suggests these data are providing a measurement of this component of the energy budget for this site which is biased low. Presumably this is because the limited number of sensors inadequately samples the points with low canopy density for this sparse crop cover.

Surface flux measurements were made at selected sites within the FIFE area. Each surface flux station was capable of measuring the fluxes of net radiation, sensible heat, and latent heat. The data contained in the Eddy Correlation Surface Flux Observations (USGS) Data Set were collected from two sites located in the northwest and southwest quadrants on slight inclines in the FIFE study area. These data are available only during the four Intensive Field Campaigns, held during the growing season of 1987, May 25 - October 17. During this period there are 66 days of data.

FIFE observations of surface fluxes

During the ice stations, measurements of the air CO2, concentration for CO2 flux between sea ice and atmosphere were made with the chamber technique. Air-sea ice CO2 fluxes were measured over the sea ice with semi-automated chambers. Sample air from the chamber is passed through Teflon tubes connected to non-dispersive infrared (NDIR) analyzer (Model 800, LICOR Inc., USA) that was connected to a system controller and data logger (Model 10x, Campbell Scientific Inc., USA), that controls the opening/closing of the chambers as well. During the observation period, the CO2 flux was measured under three different conditions or surface types: (1) a chamber was installed above snow; (2) over the bare ice after removing the snow; (3) slush layer after removing the snow and slush crystals. The CO2 concentration in the chamber was measured every 5 s during experiments lasting 20 minutes for each chamber. A one hour cycle of measurements therefore consist of three 20 minute periods from each chamber (i.e. surface type). Data available: excel files containing sampling station name for each spreadsheet, dates, sampling time and air CO2 concentration as output voltage from NDIR (to indicated as ppm we need to calculate, but, not yet done this process) in the air and chamber for CO2 flux measurement. Also see the record - SIPEX_II_Gas_Flux

This dataset provides gridded surface-atmosphere CO2 fluxes over North America from April 8 to November 18 during 2018 and 2019. Net ecosystem exchange (NEE) was estimated by the CMS-Flux-NA CO2 inversion system by assimilating in situ CO2 measurements and/or Orbiting Carbon Observatory (OCO-2) column-averaged CO2 retrievals. These data, along with imposed diurnal NEE variations, fossil fuel emissions, biomass burning, and biofuel emissions, are provided at 3-hour temporal resolution. The modeled co-samples of CO2 observed for aircraft flights are included for model evaluation. The data are provided in NetCDF version 4 format.

This dataset provides airborne eddy covariance (EC) fluxes of carbon dioxide, methane, sensible heat, and latent heat at high spatial resolution collected during the NASA Carbon Airborne Flux Experiment (CARAFE) airborne 2016 and 2017 campaigns. CARAFE utilized the NASA C-23 Sherpa aircraft with a suite of commercial and custom instrumentation. Deployment occurred across the Mid-Atlantic Region for the period 2016-09-07 through 2016-09-26 and 2017-05-03 through 2017-05-26. The data also include downwelling radiation, water vapor, pressure, temperature, wind, and aircraft navigation data. Airborne EC can quantify surface fluxes at local to regional scales, potentially helping to bridge gaps between top-down and bottom-up flux estimates and offering novel insights into biophysical and biogeochemical processes.

This data set reports 30-minute values for above-canopy meteorology and fluxes of momentum, heat, and carbon dioxide, and within-canopy carbon dioxide and water vapor concentrations collected at 12 levels between 10 cm and 64 m at the tower located within a logging gap at km 83 Tower Site in the Tapajos National Forest, Para, Brazil. Data were collected over 1.5 years between June 3, 2002 and January 30, 2004. All of the data are contained in one comma separated file.Two towers are located at the km 83 site. The first tower was installed in an intact forest area at this site in June 2000 (the 'intact' tower). In September 2001, the area adjacent to the tower was selectively logged (Bruno et al., 2006). The second tower (the 'gap tower') was installed and operating in June 2002, 400 m east of the intact tower. The gap tower was installed in the middle of a 50 m x 50 m log landing.

KORUSAQ_Model_Data features ancillary model data products for the KORUS-AQ field campaign. This product features output from the WRF model, CAM-chem, model inter-comparisons, and GEOS-chem models. Data collection for this product is complete.The KORUS-AQ field study was conducted in South Korea during May-June, 2016. The study was jointly sponsored by NASA and Korea’s National Institute of Environmental Research (NIER). The primary objectives were to investigate the factors controlling air quality in Korea (e.g., local emissions, chemical processes, and transboundary transport) and to assess future air quality observing strategies incorporating geostationary satellite observations. To achieve these science objectives, KORUS-AQ adopted a highly coordinated sampling strategy involved surface and airborne measurements including both in-situ and remote sensing instruments.Surface observations provided details on ground-level air quality conditions while airborne sampling provided an assessment of conditions aloft relevant to satellite observations and necessary to understand the role of emissions, chemistry, and dynamics in determining air quality outcomes. The sampling region covers the South Korean peninsula and surrounding waters with a primary focus on the Seoul Metropolitan Area. Airborne sampling was primarily conducted from near surface to about 8 km with extensive profiling to characterize the vertical distribution of pollutants and their precursors. The airborne observational data were collected from three aircraft platforms: the NASA DC-8, NASA B-200, and Hanseo King Air. Surface measurements were conducted from 16 ground sites and 2 ships: R/V Onnuri and R/V Jang Mok.The major data products collected from both the ground and air include in-situ measurements of trace gases (e.g., ozone, reactive nitrogen species, carbon monoxide and dioxide, methane, non-methane and oxygenated hydrocarbon species), aerosols (e.g., microphysical and optical properties and chemical composition), active remote sensing of ozone and aerosols, and passive remote sensing of NO2, CH2O, and O3 column densities. These data products support research focused on examining the impact of photochemistry and transport on ozone and aerosols, evaluating emissions inventories, and assessing the potential use of satellite observations in air quality studies.