cc-by-4.0Stagakis, StavrosBrunner, DominikLi, JunweiBackman, LeifKarvonen, AnniConstantin, LionelJärvi, LeenaHavu, MinttuChen, JiaEmberger, SophieKulmala, Liisa2025-03-242024-08-052024-08-05https://hydatakatalogi-test-24.it.helsinki.fi/handle/123456789/10561Dataset supporting the submission of the manuscript titled "Intercomparison of biogenic CO2 flux models in four urban parks in the city of Zurich" to the to the international journal "Biogeosciences". Meteorological data Hourly aggregated meteorological dataset for the urban area of Zurich, originating from two urban stations: Kaserne (8°32'/47°23'), which is a station of the Swiss national air pollution monitoring network NABEL, and Hardau II (8°30'/47°23'), which is a station established for the ICOS-Cities project.  Zurich Kaserne is located in a large courtyard. Wind and global radiation are measured on top of a four-storey building. Wind is measured at 35 m and global radiation at 27 m above ground. Hardau II station is established on the top of a high-rise building (110 m a.g.l.). Meteorological observation gaps were filled using Copernicus ERA5-Land data. Data format: comma separated values (csv) Time step: 60 min (aggregated) Time stamp: yyyy-MM-dd HH:mm, UTC, end of aggregated period Period: 01/2022–09/2023 Monthly mean atmospheric CO2 concentration data derived from the ICOS-Cities Hardau II station (07/2022–09/2023) and the Beromunster station (11/2012–02/2022). Observation gaps were filled using Copernicus ERA5-Land data. Further information on the dataset can be found in the submitted manuscript.  Data format: comma separated values (csv) Time step: Monthly (mean) Time stamp: yyyy-MM-dd  Period: 11/2012–09/2023 Variable Acronym Units Height above ground Location Geographic location Global radiation G W m-2 27 m Kaserne 8°32'/47°23' Air temperature Tair Degrees Celsius 2 m Kaserne 8°32'/47°23' Relative humidity RH % 2 m Kaserne 8°32'/47°23' Air pressure P hPa 2 m Kaserne 8°32'/47°23' Wind speed u m s-1 35 m Kaserne 8°32'/47°23' Precipitation R mm 2 m Kaserne 8°32'/47°23' Downward longwave radiation LW W m-2 110 m Hardau II, ERA-5 8°30'/47°23' Soil temperature Tsoil Degrees Celsius -0.15 m Parks - Soil water content SWC m3 m-3 -0.15 m Parks - Atmospheric CO2 concentration CO2 ppmv 2 m Hardau II, Beromunster, ERA-5 8°30'/47°23', 8°10'/47°11   In-situ ecophysiological data In-situ ecophysiology measurements performed on park trees and lawns in the city of Zurich during the ICOS-Cities project. LAI (leaf area index) was measured in dense Platanus sp. tree stands, found only in Bullingerhof and Hardaupark, during sunny conditions using a ceptometer (SS1 SunScan, Delta-T Devices). Sap flow was measured at six trees (Platanus sp., Tilia sp.), at Bullingerhof, Hardaupark and Fritschiwiese, with heat pulse sap flow sensors (3 x 3 cm probes, Implexx Sense), providing continuous measurements at 10-min sampling intervals. Daily aggregated sap flux densities (cm3 cm−2 d−1) were calculated from the 10-min data using the sensor inner thermistors, averaged for the six sampled trees. Soil and grass respiration were measured using a portable CO2 soil efflux system equipped with a 20 cm diameter survey chamber (LI-8200-01S, LI-COR Biosciences) and a CO2/H2O analyser (LI-870, LI-COR Biosciences). The observations originate from a total of 10 soil collars (Bullingerhof, Hardaupark, Fritschiwiese, Heiligfeld) separated to undisturbed grass collars (Reco, μmol CO2 m-2 s-1) and collars where the aboveground grass was clipped (Rsoil, μmol CO2 m-2 s-1). Further information on the dataset can be found in the submitted manuscript. Data format: comma separated values (csv) Time stamp: yyyy-MM-dd Period: 04/2022–09/2023   Land cover map Land cover map of part of Zurich urban area. Datasets used to derive this map: ·        Land Use Cadastre of the Canton of Zurich (https://www.geolion.zh.ch/geodatensatz/show?gdsid=443) ·        Urban Atlas (https://doi.org/10.2909/fb4dffa1-6ceb-4cc0-8372-1ed354c285e6) ·        Vegetation Height Model (VHM) from the Swiss federal forest inventory (https://opendata.swiss/de/dataset/vegetationshohenmodell-lfi) ·        Forest Mixture from the Swiss Federal Forest Inventory (https://opendata.swiss/de/dataset/waldmischungsgrad-lfi) Further information on the dataset can be found in the submitted manuscript.   Data specifications: CRS: EPSG:32632 - WGS 84 / UTM zone 32N - Projected Spatial Extent: 461972.1, 5246490.4 : 463972.1, 5248490.4 Temporal Extent: 2023 Units: meters Width: 2000 Height: 2000 Bands: 1 Pixel Size: 1,-1 Data type: Float32 - Thirty two bit floating point GDAL Driver Description: GTiff GDAL Driver Metadata: GeoTIFF   Legend: 30           Grass 40           Crops 50           Paved 60           Buildings 70           Deciduous trees 80           Water   CO2 fluxes Hourly mean CO2 fluxes estimated by the models diFUME, JSBACH, SUEWS and VPRM for the trees and lawns of the Zurich urban parks: Bullingerhof, Hardaupark, Fritschiwiese and Heiligfeld. GPP stands for gross primary productivity, Reco for ecosystem respiration and NEE for net ecosystem exchange. All fluxes are in units: μmol CO2 m-2 s-1. The parameter sets used by each model are presented in the Tables below. Further information on the dataset can be found in the submitted manuscript. Parameters used by diFUME model Parameter Value Units Description A_max 15 μmol CO2 m-2 s-1 maximum leaf gross photosynthetic rate a 0.045 mol CO2 mol-1 PAR quantum yield for CO2 assimilation a_1 25 N/A empirical coefficient in Leuning (1995) model b_ 0.65 N/A empirical coefficient in β-factor formula b_1 5 N/A empirical coefficient D_o 0.3 kPa empirically determined coefficient for the VPD scalar inside Leuning (1995) model D_sc 1 N/A daylight scalar for dark respiration inhibition during day (1: no inhibition) E_0 487.75 K temperature sensitivity parameter for soil respiration g_o 0.01 mol CO2 m-2 s-1 residual stomatal conductance for CO2 (g_s when Anet = 0, PAR = 0). Q_10 1.85 N/A temperature sensitivity of leaf respiration R_(l,ref) 1.53 μmol CO2 m-2 s-1 reference leaf respiration at Tair = 25 °C R_(S,ref) 2.49 μmol CO2 m-2 s-1 reference soil respiration at Tsoil = 10 °C T_opt 23 °C optimum air temperature for gross photosynthesis T_0 -46 °C low-temperature limit for soil respiration T_(ref,S) 10 °C reference soil temperature for soil respiration T_(ref,l) 25 °C reference air temperature for leaf respiration W 10 °C width of the bell-shape curve at f(T_air )  = 0.5 θ_ref 0.4 m3 m-3 saturated soil volumetric water content  θ_g 0.1 m3 m-3 minimum soil volumetric water content, limit to stomatal conductance θ_0 0.04 m3 m-3 minimum soil volumetric water content, limit to soil respiration   Parameters used by JSBACH model Parameter Trees Lawn Units Description J_max 104.5 148.6 μmol(CO2) m-2(leaf) s-1 Maximum electron transport rate at 25 °C T_alt 4.0–4.5   °C Alternation temperature θ_cap 0.32– 0.39 0.32– 0.34 m m-1 Volumetric soil field capacity θ_pwp 0.13– 0.21 0.135–0.165 m m-1 Volumetric wilting point V_max 55.0 78.2 μmol(CO2) m-2(leaf) s-1 Maximum carboxylation rate at 25 °C z_root 0.5 0.12 m Root depth CC 1.25 1.25 N/A Relative cost to produce one carbon f_faeces 0.3 0.3 N/A Fraction of carbon from herbivore faeces that goes into the green litter pool f_leaf 0.4 0.4 N/A A fixed fraction of canopy maintenance respiration that makes up the dark respiration k 0.1 0.09 N/A LAI growth rate during growth phase LAI_max 3.6–4.1 3.0 m2 m-2 Maximum leaf area index p veg: 0.004 rest: 0.1 growth: 0.1 dry: 0.015 N/A LAI shedding rate (trees: vegetative and rest phase; grass: growth and dry season) r_d 0.605 0.8602 μmol(CO2) m-2(leaf) s-1 Dark respiration at 25 °C, fraction of Vmax   Parameters used by SUEWS model Parameter Trees Lawn Units Description f_i 0.21 0.18 N/A Fraction of each vegetation type i F_(pho,max,i) 8.3 8.92 μmol m-2 s-1 Maximum potential photosynthesis LAI_(max,i) 4.8 3 m2 m-2 Full leaf-on summertime value LAI_(min,i) 0.66 1.6 m2 m-2 Leaf-off wintertime value T_L -10 -10 °C Lower air temperature limit T_H 55 55 °C Upper air temperature limit G_5 30 30 °C Parameter related to temperature dependence G_3 0.66 0.538 N/A Parameter related to VPD dependence G_4 0.89 0.87 N/A Parameter related to VPD dependence G_6 0.36 0.55 mm-1 Parameter related to soil moisture dependence G_2 477 263.5 W m-2 Parameter related to  dependence Δθ_WP 132.5 143 mm Wilting point deficit K_(↓max) 1200 1200 W m-2 Maximum incoming shortwave radiation a_i 0.78 1.7 N/A Empirical soil and vegetation respiration coefficient b_i 0.08 0.06 N/A Empirical soil and vegetation respiration coefficient ω_(1,GDD,i) 0.04 0.04 N/A Parameter for LAI calculation ω_(2,GDD,i) 0.0005 0.0005 N/A Parameter for LAI calculation ω_(1,SDD,i) -1.5 -1.5 N/A Parameter for LAI calculation ω_(1,SDD,i) 0.0025 0.0025 N/A Parameter for LAI calculation GDD 300 300 days The growing degree days (GDD) needed for full capacity of the leaf area index SDD -300 -300 days The senescence degree days (SDD) needed to initiate leaf off T_(base,GDD) 5 5 °C Base Temperature for initiating growing degree days (GDD) for leaf growth T_(base,SDD) 10 10 °C Base temperature for initiating senescence degree days (SDD) for leaf off   Parameters used by VPRM model Parameter Trees Lawn Units Description λ -0.16 -0.13 μmol CO2 m-2 s-1 light use efficiency PAR_0 356.99 545.61 μmol m-2 s-1 half-saturation value α 0.22 0.40 μmol CO2 m-2 s-1 /0C empirical coefficient β 1.09 0.42 μmol CO2 m-2 s-1 empirical coefficient T_max 40 40 °C maximum temperature for photosynthesis T_min 0 2 °C minimum temperature for photosynthesis T_opt 20 18 °C optimal temperature for photosynthesis T_low 0 0 °C to account for the persistence of soil respiration in winter   Data format: comma separated values (csv) Time step: 60 min (aggregated) Time stamp: yyyy-MM-dd HH:mm, UTC, end of aggregated period Period: 01/2022–09/2023Opendataset