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.

Telok Kurau, Singapore (SG-TelokKurau)

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Observations (before additional gap filling)


Site forcing metadata

title Continuous meterological forcing from SG-TelokKurau
summary Flux tower observations from Telok Kurau, Singapore 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 SG-TelokKurau
long_sitename Telok Kurau, Singapore
version v0.9
keywords urban, flux tower, eddy covariance, observations
conventions ALMA, CF, ACDD-1.3
featureType timeSeries
license Restricted dataset - contact data owner - do not distribute
time_coverage_start 2005-01-01 00:00:00
time_coverage_end 2016-02-29 16:00:00
time_analysis_start 2015-02-28 16:30:00
time_shown_in UTC
local_utc_offset_hours 8.0
timestep_interval_seconds 1800.0
timestep_number_spinup 178113
timestep_number_analysis 17568
project Urban-PLUMBER: “Harmonized, gap-filled dataset from 20 urban flux tower sites”
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 Eric Velasco (evelasco@mce2.org, he_velasco2003@yahoo.com), Matthias Roth (geomr@nus.edu.sg)
observations_reference Roth, Jansson and Velasco (2017) https://doi.org/10.1002/joc.4873; Velasco, Roth, Tan, Quak, Nabarro, Norford. (2013) https://doi.org/10.5194/acp-13-10185-2013; Flux tower website: https://www.nusurbanclimate.com/tkfluxtowersingapore
date_created 2021-09-19 02:16:37
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 ERA5 data for gap-filling is from adjacent grid over land. Near surface air temperature at 2m. SoilTemp is at 2cm depth.
history v0.9 (2021-09-08): beta issue

Site images

Region Regional map. © OpenStreetMap site_map Site map with 500 m radius. © OpenStreetMap
site_photo Site photo. © M. Roth 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 1.3143 degrees_north Roth et al. 2017 https://doi.org/10.1002/joc.4873
2 longitude 103.911 degrees_east Roth et al. 2017 https://doi.org/10.1002/joc.4873
3 ground_height 5 m Velasco et al. 2013 https://doi.org/10.5194/acp-13-10185-2013
4 measurement_height_above_ground 23.5 m Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
5 impervious_area_fraction 0.85 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
6 tree_area_fraction 0.11 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
7 grass_area_fraction 0.04 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
8 bare_soil_area_fraction 0 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
9 water_area_fraction 0 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
10 roof_area_fraction 0.39 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
11 road_area_fraction 0.12 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
12 other_paved_area_fraction 0.34 1 Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
13 building_mean_height 9.9 m Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
14 tree_mean_height 7.3 m Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
15 roughness_length_momentum 0.8 m Roth et al. 2017 (morphometric) https://doi.org/10.1002/joc.4873
16 displacement_height 7.34 m Roth et al. 2017 (morphometric) https://doi.org/10.1002/joc.4873
17 canyon_height_width_ratio 0.61 1 Demuzere et al. 2017 https://doi.org/10.1002/qj.3028
18 wall_to_plan_area_ratio 0.66 1 Liu et al. 2017 https://iopscience.iop.org/article/10.1088/1748-9326/aa7ee7
19 average_albedo_at_midday 0.168 1 median of observations -
20 resident_population_density 7490 person/km2 Roth et al. 2017 https://doi.org/10.1002/joc.4873
21 anthropogenic_heat_flux_mean 11 W/m2 Quah and Roth 2012 https://doi.org/10.1016/j.atmosenv.2011.10.015
22 topsoil_clay_fraction 0.048 1 Velasco et al. 2021 https://doi.org/10.1016/j.jenvman.2020.111752
23 topsoil_sand_fraction 0.165 1 Velasco et al. 2021 https://doi.org/10.1016/j.jenvman.2020.111752
24 topsoil_bulk_density 1080 kg/m3 Velasco et al. 2021 https://doi.org/10.1016/j.jenvman.2020.111752
25 building_height_standard_deviation 4 m Tower website https://www.nusurbanclimate.com/tkfluxtowersingapore
26 roughness_length_momentum_mac 0.49 m Macdonald method derived from morphology using eq. 26 of Macdonald et al. (1998)
27 displacement_height_mac 6.52 m Macdonald method derived from morphology using eq. 23 of Macdonald et al. (1998)
28 roughness_length_momentum_kanda 0.54 m Kanda method derived from morphology using eq. 12a of Kanda et al. (2013)
29 displacement_height_kanda 13.07 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


Tair2m 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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