This dataset contains the time series of isoprene concentrations measured at Wytham Woods in the summer of 2018 during the Wytham Isoprene iDirac Oak Tree Measurements (WIsDOM) campaign, part of the NERC funded Biodiversity and Land Use Impacts on Tropical Forest Ecosystem Function (BALI) project. Isoprene is the largest biogenic emission on the planet and impacts air composition and climate. Seasonal data is important to underpin the biosphere-atmosphere exchange. A portable gas chromatograph, the iDirac (Bolas et al., Atmos. Meas. Tech, 2020) was used to monitor isoprene for a whole growing season (May-end September) in 2018 at Wytham Woods, an ancient woodland in the UK. Measurements were collected at 4 heights across the forest canopy: at ground level (0.53 m, inlet 1), in the under storey (7.25 m, inlet 2), at the crown level (13.17 m, inlet 3) and above the canopy (15.55 m, inlet 4). Ancillary data (air temperature and photosynthetic active radiation, or PAR) were also collected. The WIsDOM campaign was a joint effort of Cranfield University and the University of Cambridge.

The Quantifying the Amazon Isoprene Budget: Reconciling Top-down versus Bottom-up Emission Estimates project produced a unique high resolution model (GEOS-Chem version v8-03-01 - with modifications) for the Amazon, which simulated isoprene emissions and atmospheric chemistry. Model outputs associated with Barkley et al. publication is available through CEDA-BADC. An evaluation of a nested high-resolution Goddard Earth Observing System (GEOS)-Chem chemistry transport model simulation of tropospheric chemistry over tropical South America is presented. The model has been constrained with two isoprene emission inventories: (1) the canopy-scale Model of Emissions of Gases and Aerosols from Nature (MEGAN) and (2) a leaf-scale algorithm coupled to the Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) dynamic vegetation model, and the model has been run using two different chemical mechanisms that contain alternative treatments of isoprene photo-oxidation. The publication is: Barkley, M. P., P. I. Palmer, L. Ganzeveld , A. Arneth , D. Hagberg , T. Karl , A. Guenther , F. Paulot , P. Wennberg , J. Mao , T. Kurosu , K. Chance , J.-F. Muller, I. De Smedt , M. Van Roozendael , D. Chen , Y. Wang , R. Yantosca, Can a 'state of the art' chemistry transport model really simulate Amazonian tropospheric chemistry?, J. Geophys. Res., 116, D16302, doi:10.1029/2011JD015893, 2011 This is a NERC funded project.

The Quantifying the Amazon Isoprene Budget: Reconciling Top-down versus Bottom-up Emission Estimates project produced a unique high resolution model (GEOS-Chem version v8-03-01 - with modifications) for the Amazon, which simulated isoprene emissions and atmospheric chemistry. A nested-grid version of the GEOS-Chem chemistry transport model, constrained by isoprene emissions from the Model of Emissions of Gases and Aerosols from Nature (MEGAN), and the Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) bottom-up inventories, was used to evaluate the impact that surface isoprene emissions have on formaldehyde (HCHO) air-mass factors (AMFs) and vertical column densities (VCDs) over tropical South America during 2006, as observed by the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) and Ozone Monitoring Instrument (OMI). Results of this project are presented in the following publication: Barkley, M. P., T. P. Kurosu, K. Chance, I. De Smedt, M. Van Roozendael, A. Arneth, D. Hagberg, and A. Guenther: Assessing sources of uncertainty in formaldehyde air mass factors over tropical South America: Implications for top-down isoprene emission estimates, J. Geophys. Res., 117, D13304, doi:10.1029/2011JD016827. 2012 and model outputs associated to this project are archived at CEDA. This was a NERC funded project.

The Quantifying the Amazon Isoprene Budget: Reconciling Top-down versus Bottom-up Emission Estimates project ran a unique high resolution model for the Amazon basin, able to simulate isoprene emissions and atmospheric chemistry. Model outputs are available through CEDA. This was a NERC funded project (NE/G013810/1).

The Quantifying the Amazon Isoprene Budget: Reconciling Top-down versus Bottom-up Emission Estimates project produced a unique high resolution model (GEOS-Chem version v8-03-01 - with modifications) for the Amazon, which simulated isoprene emissions and atmospheric chemistry. Formaldehyde (HCHO) vertical column measurements from the Scanning Imaging Absorption spectrometer for Atmospheric Cartography (SCIAMACHY) and Ozone Monitoring Instrument (OMI), and a nested-grid version of the GEOS-Chem chemistry transport model, are used to infer an ensemble of top-down isoprene emission estimates from tropical South America during 2006, using different model configurations and assumptions in the HCHO air-mass factor (AMF) calculation. Scenes affected by biomass burning are removed on a daily basis using fire count observations, and the local model sensitivity was used to identify locations where the impact of spatial smearing is small, though this comprises spatial coverage over the region Results of this project are presented in the following publication: Barkley, M. P., et al. (2013), Top-down isoprene emissions over tropical South America inferred from SCIAMACHY and OMI formaldehyde columns, J. Geophys. Res. Atmos., 118, 6849–6868, doi:10.1002/jgrd.5055 and model outputs associated to this project are archived at CEDA. This was a NERC funded project.