3.9.3. LI7500A

3.9.3.1. Introduction

Li-Cor LI7500A infrared gas analyser. An open path CO2 and H2O analyser. This is often used to measure CO2 and H2O densities in turbulent structures as part of an eddy-covariance set up, along with a 3D Sonic Anemometor, to determine various energy fluxes.

3.9.3.2. Manufacturer and Model

Model

Brand

Type

Li7500A

Li-Cor

Gas Analyser

3.9.3.3. Output definitions

Ouput definition ID

File Identifier

Level Number

QAQC notes

File time resolution

LI7500A

Li7500_%SITE

0

None

10Hz

LI7500A

Li7500_%SITE

0

None

30min

LI7500A

Li7500_%SITE

1

QAQC

10Hz

LI7500A

Li7500_%SITE

1

QAQC

30min

LI7500A

Li7500_%SITE

2

QAQC_IMAS

10Hz

LI7500A

Li7500_%SITE

2

QAQC_IMAS

30min

Li7500_ECpack

Li7500_ECpack_%SITE

0

No QAQC

30min

Li7500_ECpack

Li7500_ECpack_%SITE

1

QAQC

30min

Li7500_ECpack

Li7500_ECpack_%SITE

2

QAQC

30min

LI7500A_10Hz

Li7500_%SITE

0

No_QAQC

10Hz

LI7500A_10Hz

Li7500_%SITE

1

QAQC

10Hz

LI7500A_10Hz

Li7500_%SITE

2

QAQC

10Hz

3.9.3.4. Processing code

Code used to process raw data: https://github.com/Urban-Meteorology-Reading/Operations-FLUX

3.9.3.5. Variables measured by instrument

Table 3.7 Variables measured - sorted alphabetically

Variable ID

Full Name

Unit

Lower Threshold

Upper Threshold

Files present (Output definition ID,Level No,Time resolution)

C_CO2

carbon_dioxide_concentration

mmol.m-3

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min LI7500A_10Hz,0,10Hz LI7500A_10Hz,1,10Hz LI7500A_10Hz,2,10Hz

C_CO2_kg_per_kg

carbon_dioxide_concentration_kg_per_kg

kg.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

C_H2O

water_vapour_concentration

mmol.m-3

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min LI7500A_10Hz,0,10Hz LI7500A_10Hz,1,10Hz LI7500A_10Hz,2,10Hz

CO2_absorp

carbon_dioxide_absorptance

N/A

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min LI7500A_10Hz,0,10Hz LI7500A_10Hz,1,10Hz LI7500A_10Hz,2,10Hz

cov_qC_CO2

covariance_qC_CO2

kg2.kg-2

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_TsonicC_CO2

covariance_TsonicC_CO2

K.kg.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_Tsonicq

covariance_Tsonicq

K.kg.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_uC_CO2

covariance_uC_CO2

m.kg.s-1.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_uq

covariance_uq

m.kg.s-1.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_vC_CO2

covariance_vC_CO2

m.kg.s-1.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_vq

covariance_vq

m.kg.s-1.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_wC_CO2

covariance_wC_CO2

m.kg.s-1.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

cov_wq

covariance_wq

m.kg.s-1.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

diag

diagnostics

N/A

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min LI7500A_10Hz,0,10Hz LI7500A_10Hz,1,10Hz LI7500A_10Hz,2,10Hz

diag_pct

diagnostics_percentage

%

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min

F_CO2

upward_turbulent_carbon_dioxide_flux

umol.m-2.s-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

FLAG

Status flag

N/A

LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

H2O_absorp

water_vapour_absorptance

dimensionless

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min LI7500A_10Hz,0,10Hz LI7500A_10Hz,1,10Hz LI7500A_10Hz,2,10Hz

imas

imas flag

N/A

LI7500A_10Hz,2,10Hz

imas_pct

identification_microscale_anthropogenic_sources

%

LI7500A,2,10Hz LI7500A,2,30min

nSamples

nSamples

samples/interval

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

q

specific_humidity

kg.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

Q_E

upward_turbulent_latent_heat_flux

W.m-2

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

sd_C_CO2

standard_deviation_CO2

mmol.m-3

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min

sd_C_CO2_kg_per_kg

standard_deviation_CO2_kg_per_kg

kg.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

sd_C_H2O

standard_deviation_H2O

mmol.m-3

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min

sd_CO2_absorp

standard_deviation_CO2_absorp

N/A

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min

sd_H2O_absorp

standard_deviation_H2O_absorp

N/A

LI7500A,0,10Hz LI7500A,0,30min LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min

sd_q

standard_deviation_q

kg.kg-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

spike

spike_flag

N/A

LI7500A_10Hz,1,10Hz LI7500A_10Hz,2,10Hz

spike_pct

spike_percentage

%

LI7500A,1,10Hz LI7500A,1,30min LI7500A,2,10Hz LI7500A,2,30min

tol_F_CO2

tolerance_F_CO2

umol.m-2.s-1

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

tol_Q_E

tolerance_Q_E

W.m-2

Li7500_ECpack,0,30min Li7500_ECpack,1,30min Li7500_ECpack,2,30min

3.9.3.6. Serials

Serial

Suffix

75H-0995

A

75H-1124

B

75H-1973

C

3.9.3.7. Deployments

3.9.3.7.1. Serial number: 75H-1973

Site ID

Start date

End date

KSK

2011-08-19 00:00

2011-08-22 00:00

KSK

2011-08-22 00:00

2011-09-06 00:00

KSK

2011-09-06 00:00

2011-10-06 00:00

KSK

2011-10-06 00:00

2011-12-21 00:00

KSK

2011-12-21 00:00

2013-02-27 00:00

KSNW

2013-03-17 00:00

2015-09-17 00:00

KSB

2015-09-17 00:00

2016-02-18 00:00

IMU

2016-04-29 00:00

2020-11-04 00:00

3.9.3.7.2. Serial number: 75H-1124

Site ID

Start date

End date

URAO

2015-07-19 00:00

2017-03-09 00:00

URAO

2017-03-14 00:00

2017-04-27 00:00

URAO

2017-04-27 00:00

2020-07-07 00:00

URAO

2021-03-10 00:00

3.9.3.7.3. Serial number: 75H-0995

Site ID

Start date

End date

KSK

2008-10-01 00:00

2008-10-29 00:00

KSK

2008-10-29 00:00

2009-04-29 00:00

KSK

2009-04-29 00:00

2009-05-14 00:00

KSK

2009-05-14 00:00

2009-10-06 00:00

KSS

2009-11-01 00:00

2012-03-25 00:00

KSSW

2012-03-26 00:00

2013-03-26 00:00

KSSW

2013-03-26 00:00

2013-04-01 00:00

KSSW

2013-04-01 00:00

2013-05-09 00:00

KSSW

2013-05-10 00:00

2016-09-14 00:00

KSSW

2016-09-15 00:00

2017-06-13 00:00

3.9.3.8. Photos

../../../_images/tower-lowering-15092016_29073458334_o1.jpg

Fig. 3.13 At KSSW 15/09/2016

../../../_images/102_1940_23004725333_o1.jpg

Fig. 3.14 At KSNW 05/07/2015

../../../_images/2016-04-18-173022_26453291121_o.jpg

Fig. 3.15 At IMU 18/04/2016

../../../_images/ksk_mast_1_23679118412_o(1).jpg

Fig. 3.16 At KSK 19/08/2011

../../../_images/r0015029_23161117173_o(1)1.jpg

Fig. 3.17 Atop tower KSS 08/04/2011.

3.9.3.9. Supplementary information

Link

Title

Description

LI7500A/RS manual

LI7500A/RS manual

Manual from Li-Cor.

LI7500A brochure

LI7500A brochure

Brochure from Li-Cor.

3.9.3.10. Data acquisition

Data can be requested from Prof. Sue Grimmond (c.s.grimmond@reading.ac.uk).

3.9.3.11. References

  1. Bjorkegren, A. and Grimmond, C. S. B., (2017) Net carbon dioxide emissions from central London. Urban Climate, 23. pp. 131-158. ISSN 2212-0955 doi: https://doi.org/10.1016/j.uclim.2016.10.002

  2. Helfter, C., Tremper, A. H., Halios, C. H., Kotthaus, S., Bjorkegren, A., Grimmond, C. S. B., Barlow, J. F. and Nemitz, E. (2016) Spatial and temporal variability of urban fluxes of methane, carbon monoxide and carbon dioxide above London, UK. Atmospheric Chemistry and Physics, 16 (16). pp. 10543-10557. ISSN 1680-7316 doi: https://doi.org/10.5194/acp-16-10543-2016

  3. Bjorkeren, A. B., Grimmond, C. S. B., Kotthaus, S. and Malamud, B. D. (2015) CO2 emission estimation in the urban environment: measurement of the CO2 storage term. Atmospheric Environment, 122. pp. 775-790. ISSN 1352-2310 doi: https://doi.org/10.1016/j.atmosenv.2015.10.012

  4. Font, A., Grimmond, C. S. B., Kotthaus, S., Morgu�, J. -A., Stockdale, C., O’Connor, E., Priestman, M. and Barratt, B. (2015) Daytime CO2 urban surface fluxes from airborne measurements, eddy-covariance observations and emissions inventory in Greater London. Environmental Pollution, 196. pp. 98-106. ISSN 0269-7491 doi: https://doi.org/10.1016/j.envpol.2014.10.001

  5. Best, M. J. and Grimmond, C. S. B. (2015) Key conclusions of the first international urban land surface model comparison project. Bulletin of the American Meteorological Society, 96 (5). pp. 805-819. ISSN 1520-0477 doi: https://doi.org/10.1175/BAMS-D-14-00122.1

  6. Kotthaus, S. and Grimmond, C. S. B. (2014) Energy exchange in a dense urban environment – part I: temporal variability of long-term observations in central London. Urban Climate, 10 (2). pp. 261-280. ISSN 2212-0955 doi: https://doi.org/10.1016/j.uclim.2013.10.002

  7. Magliulo, V., Toscano, P., Grimmond, C. S. B., Kotthaus, S., J�rvi, L., Set�l�, H., Lindberg, F., Vogt, R., Staszewski, T., Bubak, A., Synnefa, A. and Santamouris, M. (2014) Environmental measurements in BRIDGE case studies. In: Chrysoulakis, N., de Castro, E. A. and Moors, E. J. (eds.) Understanding Urban Metabolism. Routledge, pp. 45-57. ISBN 9780415835114

  8. Best, M. J. and Grimmond, C. S. B. (2013) Analysis of the seasonal cycle within the first international urban land-surface model comparison. Boundary-Layer Meteorology, 146 (3). pp. 421-446. ISSN 1573-1472 doi: https://doi.org/10.1007/s10546-012-9769-7

  9. Kotthaus, S. and Grimmond, C. S. B. (2012) Identification of micro-scale anthropogenic CO2, heat and moisture sources – processing eddy covariance fluxes for a dense urban environment. Atmospheric Environment, 57. pp. 301-316. ISSN 1352-2310 doi: https://doi.org/10.1016/j.atmosenv.2012.04.024

  10. Grimmond, C. S. B., Blackett, M., Best, M. J., Baik, J. J., Belcher, S. E., Beringer, J., Bohnenstengel, S. I., Calmet, I., Chen, F., Coutts, A., Dandou, A., Fortuniak, K., Gouvea, M. L., Hamdi, R., Hendry, M., Kanda, M., Kawai, T., Kawamoto, Y., Kondo, H., Krayenhoff, E. S., Lee, S. H., Loridan, T., Martilli, A., Masson, V., Miao, S., Oleson, K., Ooka, R., Pigeon, G., Porson, A., Ryu, Y. H., Salamanca, F., Steeneveld, G. J., Tombrou, M., Voogt, J. A., Young, D.T. and Zhang, N. (2011) Initial results from Phase 2 of the international urban energy balance model comparison. International Journal of Climatology, 31 (2). pp. 244-272. ISSN 1097-0088 doi: https://doi.org/10.1002/joc.2227

Tip

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