A multi-site model evaluation project for urban areas

Phase 2 Phase 1 Download project protocol
Mathew Lipson (UNSW), Sue Grimmond (Reading), Martin Best (Met Office),
with observational and modelling participants.

West Phoenix, Arizona, United States (US-WestPhoenix)

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Observations (before additional gap filling)


Site forcing metadata

title Continuous meterological forcing from US-WestPhoenix
summary Flux tower observations from West Phoenix, Arizona, United States after quality control, with gap filling from bias corrected ERA5 surface meteorological data. Developed for use in the Urban-PLUMBER model evaluation project. Attribute any use to “Harmonized, gap-filled dataset from 20 urban flux tower sites”
sitename US-WestPhoenix
long_sitename West Phoenix, Arizona, United States
version v1
keywords urban, flux tower, eddy covariance, observations
conventions ALMA, CF, ACDD-1.3
featureType timeSeries
license CC-BY-4.0: https://creativecommons.org/licenses/by/4.0/
time_coverage_start 2001-01-01 00:00:00
time_coverage_end 2013-01-01 06:30:00
time_analysis_start 2011-12-16 18:30:00
time_shown_in UTC
local_utc_offset_hours -7.0
timestep_interval_seconds 1800.0
timestep_number_spinup 192085
timestep_number_analysis 18313
project Urban-PLUMBER multi-site model evaluation project for urban areas
references Data from “Harmonized gap-filled dataset from 20 urban flux tower sites”: https://doi.org/10.5281/zenodo.5517550
project_contact Mathew Lipson (m.lipson@unsw.edu.au), Sue Grimmond (c.s.grimmond@reading.ac.uk), Martin Best (martin.best@metoffice.gov.uk)
observations_contact Stevan Earl: caplter.data@asu.edu, Winston Chow: winstonchow@smu.edu.sg
observations_reference Chow (2017): https://doi.org/10.6073/pasta/fed17d67583eda16c439216ca40b0669; Chow et al (2014): https://doi.org/10.1002/joc.3947
date_created 2022-09-22 16:59:14
source https://github.com/matlipson/urban-plumber_pipeline
other_references ERA5: Copernicus Climate Change Service (C3S) (2017): https://cds.climate.copernicus.eu/cdsapp#!/home NCI Australia: http://doi.org/10.25914/5f48874388857
acknowledgements Contains modified Copernicus Climate Change Service Information 2021 (ERA5 hourly data on single levels). Data from replica hosted by NCI Australia.
comment SoilTemp at 2cm depth.
history v0.9 (2021-09-08): beta issue; v1 (2022-09-15): with publication in ESSD

Site images

Region Regional map. © OpenStreetMap site_map Site map with 500 m radius. © OpenStreetMap
site_photo Site photo. © S. Earl site_sat Site aerial photo with 500 m radius. © OpenStreetMap, Microsoft

Maps developed from: Hrisko, J. (2020). Geographic Visualizations in Python with Cartopy. Maker Portal.

Site characteristics

id parameter value units source doi
1 latitude 33.4839 degrees_north Chow et al. (2014) https://doi.org/10.1002/joc.3947
2 longitude -112.143 degrees_east Chow et al. (2014) https://doi.org/10.1002/joc.3947
3 ground_height 340 m Chow et al. (2014) https://doi.org/10.1002/joc.3948
4 measurement_height_above_ground 22.1 m Chow et al. (2014) https://doi.org/10.1002/joc.3949
5 impervious_area_fraction 0.48 1 Chow et al. (2014) https://doi.org/10.1002/joc.3950
6 tree_area_fraction 0.05 1 Chow et al. (2014) https://doi.org/10.1002/joc.3951
7 grass_area_fraction 0.1 1 Chow et al. (2014) https://doi.org/10.1002/joc.3952
8 bare_soil_area_fraction 0.37 1 Chow et al. (2014) https://doi.org/10.1002/joc.3953
9 water_area_fraction 0 1 Chow et al. (2014) https://doi.org/10.1002/joc.3954
10 roof_area_fraction 0.26 1 Chow et al. (2014) https://doi.org/10.1002/joc.3955
11 road_area_fraction 0.22 1 Chow et al. (2014) https://doi.org/10.1002/joc.3956
12 other_paved_area_fraction 0 1 included in road fraction -
13 building_mean_height 4.5 m Chow et al. (2014) https://doi.org/10.1002/joc.3958
14 tree_mean_height 4 m Chow et al. (2014) https://doi.org/10.1002/joc.3959
15 roughness_length_momentum 0.6 m Chow, pers. comms -
16 displacement_height 3 m Chow, pers. comms -
17 canyon_height_width_ratio 0.4 1 Chow et al. (2014) https://doi.org/10.1002/joc.3959
18 wall_to_plan_area_ratio 0.59 1 estimated, see notes derived from Eq. 1 in Masson et al. 2020
19 average_albedo_at_midday 0.172 1 median of observations -
20 resident_population_density 2500 person/km2 Statistical Atlas (2020) https://statisticalatlas.com/neighborhood/Arizona/Phoenix/Maryvale/Population
21 anthropogenic_heat_flux_mean 21.1 W/m2 Varquez et al (2021) https://doi.org/10.1038/s41597-021-00850-w
22 topsoil_clay_fraction 0.2 1 OpenLandMap https://doi.org/10.5281/zenodo.2525663
23 topsoil_sand_fraction 0.4 1 OpenLandMap https://doi.org/10.5281/zenodo.2525662
24 topsoil_bulk_density 1500 kg/m3 OpenLandMap https://doi.org/10.5281/zenodo.2525665
25 building_height_standard_deviation 1.025 m estimated, see notes derived using eq. 2 of Kanda et al. 2013
26 roughness_length_momentum_mac 0.42 m Macdonald method derived from morphology using eq. 26 of Macdonald et al. (1998)
27 displacement_height_mac 2.24 m Macdonald method derived from morphology using eq. 23 of Macdonald et al. (1998)
28 roughness_length_momentum_kanda 0.31 m Kanda method derived from morphology using eq. 12a of Kanda et al. (2013)
29 displacement_height_kanda 4.47 m Kanda method derived from morphology using eq. 10a of Kanda et al. (2013)

Site forcing

SWdown forcing


LWdown forcing


Tair forcing


Qair forcing


PSurf forcing


Rainf forcing


Snowf forcing


Wind_N forcing


Wind_E forcing


Quality control (qc) and gap filling procedure

QC process on observations

  1. Out-of-range: removal of unphysical values (e.g. negative shortwave radiation) using the ALMA expected range protocol.
  2. Night: nocturnal shortwave radiation set to zero, excluding civil twilight (when the sun is 6° below the horizon).
  3. Constant: four or more timesteps with the same value (excluding zero values for shortwave radiation, rainfall and snowfall) are removed as suspicious.
  4. Outlier: remove values outside ±4 standard deviations for each hour in a rolling 30-day window (to account for diurnal and seasonal variations). Repeat with a larger tolerance (± 5 standard deviations) until no outliers remain. The outlier test is not applied to precipitation.
  5. Visual: remaining suspect readings are removed manually via visual inspection.

Gap-filling process

LWdown diurnal qc


LWup diurnal qc


PSurf diurnal qc


Qair diurnal qc


Qh diurnal qc


Qle diurnal qc


Qtau diurnal qc


Rainf diurnal qc


SWdown diurnal qc


SWup diurnal qc


Snowf diurnal qc


SoilTemp diurnal qc


Tair diurnal qc


Wind_E diurnal qc


Wind_N diurnal qc


Bias correction diurnal comparison

Four methods drawing on ERA5 reanalysis are compared relative to the quality-controlled flux tower data. The methods are:

  1. ERA5: the nearest land based 0.25° resolution ERA5 grid (i.e. without bias correction)
  2. WFDE5: the nearest WFDE5 grid (which use 0.5° gridded monthly observations for bias correction)
  3. UP: the Urban-PLUMBER methods used in this collection (using site observations for bias correction)
  4. LN: linear methods based on FLUXNET2015 (using site observations for bias correction)

ERA5 bias correction

The UP methods are as follows:

Mean absolute error (MAE) is shown in the legend.

Tair diurnal bias correction


Qair diurnal bias correction


PSurf diurnal bias correction


LWdown diurnal bias correction


SWdown diurnal bias correction


Wind diurnal bias correction


Rainf diurnal bias correction


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