3. 3ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Project Carbosense4D (www.carbosense.ch)
Goals:
Determine CO2 emissions of the city of Zurich over multiple years
Enhance understanding of biospheric CO2 fluxes over Switzerland
Describe accurately the 4-D evolution of CO2 over Switzerland
Learn about sensor networks
sensor integration and characterization
network setup and operation
communication and data processing
Quality Assurance & Quality Control
low-cost
sensors
low-cost
network=
5. 5ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Sensor calibration and characterization
CO2 sensors respond to temperature, pressure, humidity
Multi-factor model using Beer-Lambert’s law applied to IR detector output
CO2 (350 – 1000 ppm)
T (-5°C – 50°C)
CO2 (400 – 900 ppm)
p (770 – 1050 hPa), T
Climate chamber Pressure chamber
CO2, T, RH
Ambient measurements
6. 6ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
First year of operation of low-cost LP8 sensors in Zurich
10-17 Jul 2017
Sensors not stable enough for accurate long-term measurements
Frequent recalibration too demanding
13-20 Aug 2018
Can we correct for drifts while sensors are in operation?
7. 7ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Operational sensor data processing
Outlier removal
specifying valid operating range
accounting for sensor drift and ageing
Including
outliers
Outliers
removed
T (°C) T (°C)
-log(IR)
-log(IR)
Sensor drift adjustment
using periods of strong winds
(> 2 m s-1 during at least 1 h)
July 2017 Aug 2018
CO2adjustment[ppm]
8. 8ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Before drift correction
Sensor drift adjustment
July 2017 Aug 2018
Offset relative to nearby accurate sensor
CO2adjustment[ppm]Operational sensor data processing
Periods of strong winds
After drift correction
9. 9ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Amplitude of diurnal variation
July 2018
Jan 2018
10. 10ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
CO2 modelling with COSMO-GHG
Weather prediction model COSMO with GHG tracer extension
Domain centered over Switzerland, 1 km x 1 km resolution, 60 levels
Highly efficient code, fully ported to GPUs
CO2-boundary conditions
Global CO2 model CAMS
(ECMWF, experiment ghqy)
Emissions
TNO/MACC-3 (Europe) +
CarboCount (Switzerland)
Biosphere fluxes
VPRM (MPI Jena)
11. 11ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Animation of anthropogenic CO2 in last week of Oct 2017
12. 12ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Comparison with observations, Oct 2017
Beromünster, rural, 212 m a.g.l. Dübendorf, suburban, 4 m a.g.l
CO2CO2
anthrop.
biospheric
background
RESP x 4, GPP x 2
T T
Wind speedWind speed
Too strong vertical mixing,
surface not sufficiently
decoupled from higher levels
model
observations
13. 13ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch
Conclusions and outlook
Conclusions
First year of data from ~200 LP8 sensors, HPP just starting
Approx. accuracy: Picarro 0.1 ppm, HPP 1.0 ppm, LP8 10 ppm
Strong contribution from biosphere even in Zurich
First model results encouraging, areas of improvement identified
Outlook
Sensors: Deployment of HPPs, further improvement of LP8 data
Model: Meteo data assimilation, PBL mixing, online emissions & VPRM
Integration of model and sensor data:
Use model as transfer standard between Picarro/HPP and LP8
Geostatistical modeling of differences COSMO-GHG and sensor data
Further develop city-scale model with final goal of estimating emissions
14. 14ICOS Science Conference 2018, Prague, 11-13 Sep 2018 | dominik.brunner@empa.ch O. Wehrli 2013
With a special thanks to
Swisscom, MeteoSwiss, UGZ Zurich, NABEL and others
for generous support of our sensor network
Markus Leuenberger (University of Bern) for Beromünster CO2 observations
Christoph Gerbig (MPI Jena)
for VPRM data
Copernicus Atmospheric Monitoring Service (CAMS)
for global CO2 model data
Funding through Swiss Data Science Center (SDSC) and EU / Eurostars