Penlee Point Observatory

Penlee Point Observatory

The Penlee Point Atmospheric Observatory (PPAO) was established by the Plymouth Marine Laboratory in May 2014 for long term observations of ocean-atmosphere interaction. The observatory is only a few tens of metres away from the water edge and 11m above mean sea level.

Penlee Observatory

Location and typical winds

At the mouth of the Plymouth Sound, the site (50° 19.08' N, 4° 11.35' W) is exposed to marine air when the wind comes from 110° - 240°. Typical southwesterly winds tend to bring relatively clean background Atlantic air. In contrast, winds from the southeast are often contaminated by exhaust plumes from passing ships. The PPAO is in close proximity to marine sampling stations that form the Western Channel Observatory, enabling better understanding of the ocean-atmosphere coupling.

Measurements at PPAO

Continuous gas phase measurements at PPAO include concentrations of sulphur dioxide (SO2), ozone (O3), carbon dioxide (CO2), and methane (CH4) in air. Aerosol number (>0.003 μm diameter), size distribution (0.24-18.5 μm diameter), composition (major ions, organics, and trace metals) and meteorology are also measured. We directly quantify the air-sea transport of CO2, CH4, and aerosols using the state-of-the-art eddy covariance technique. Continuous observations at PPAO also allow us to quantify the impact of anthropogenic activity on the coastal environment as well as the influence of the sea on the nearby land.

Trinity House own the Penlee building and allow PML to occupy the site under licence so that instrumentation can be protected from the elements. We are able to access the site thanks to the cooperation of Mount Edgcumbe Estate. We would like to thank Universities of Plymouth, East Anglia, Leeds, and National Oceanographic Centre for their collaborative measurements. The PPAO is a SOLAS endorsed integrated atmosphere-ocean time series station

Full Data Available

Figures shown below in the data viewer contain averages of the raw, uncalibrated data. If you would like access to the calibrated data, or you would like to know more about the observatory, please contact Mingxi Yang and Tom Bell at Data are available from CEDA but please let us know if using our data so we can ensure it is properly referenced.


O3-SML (2019-2021): Ozone and the surface microlayer (PML PI-Bell)

ACSIS (2016 - 2021): Monitoring long term atmospheric composition changes over the North Atlantic (PML PI - Yang)

ACRUISE (2019 - 2022): Understanding the impacts of ship emission regulations on air quality and climate (PI - Yang)

SCIPPER (2019 - 2022): EC Horizon 2020 funded project investigating techniques for the regulatory monitoring of ship emissions (PML PI - Smyth)

MOYA (2016 - 2020): Improving the global atmospheric methane budget (PML PI - Yang)

Latest Webcam imagery

Penlee Point Webcam



Phillips, D. P., Hopkins, F. E., Bell, T. G., Liss, P. S., Nightingale, P. D., Reeves, C. E., Wohl, C., and Yang, M.: Air–sea exchange of acetone, acetaldehyde, DMS and isoprene at a UK coastal site. Atmos. Chem. Phys., 21, 10111–10132, 2021 10.5194/acp-21-10111-2021

White, C., Ussher, S.J., Fitzsimons, M.F., Atkinson, S., Woodward, E.M.S., Yang, M., Bell, T.G.: Inorganic nitrogen and phosphorus in Western European aerosol and the significance of dry deposition flux into stratified shelf waters. Atmospheric Environment 261, 118391, 2021 10.1016/j.atmosenv.2021.118391


Loades, D. C., Yang, M., Bell, T. G., Vaughan, A. R., Pound, R. J., Metzger, S., Lee, J. D., and Carpenter, L. J.: Ozone deposition to a coastal sea: comparison of eddy covariance observations with reactive air-sea exchange models. Atmos. Meas. Tech., 13, 6915-6931, 2020, 10.5194/amt-13-6915-2020

Bell, T.G., Yang, M. and Ussher, S.J: Atmospheric emissions from ships. Chapter 2 in Environmental Impact of Ships, Cambridge Press, November 2020.
Please contact us if you are interested in this publication.

M Yang, JCE Buxmann, H Delbarre, M Fourmentin, TJ Smyth: Temporal and spatial trends in aerosols near the English Channel. An air quality success story? Atmospheric Environment: X, 6, 100074, 10.1016/j.aeaoa.2020.100074


Yang, M., Norris, S. J., Bell, T. G., and Brooks, I. M.: Sea spray fluxes from the southwest coast of the United Kingdom dependence on wind speed and wave height. Atmos. Chem. Phys., 19, 15271-15284, 2019, 10.5194/acp-19-15271-2019

Yang, M, Bell, TG, Brown IJ, Fishwick JR, Kitidis, V, Nightingale, PD, Rees, AP, and Smyth TJ: Insights from year-long measurements of air-water CH4 and CO2 exchange in a coastal environment ,Biogeosciences, 16, 961-978, 10.5194/bg-16-961-2019


Sommariva R, Hollis LDJ, Sherwen T, et al.: Seasonal and geographical variability of nitryl chloride and its precursors in Northern Europe, Atmos Sci Lett. 2018, 19:e844, 10.1002/asl.844


Yang, M., Bell, T. G., Hopkins, F. E., Kitidis, V., Cazenave, P. W., Nightingale, P. D., Yelland, M. J., Pascal, R. W., Prytherch, J., Brooks, I. M., and Smyth, T. J.: Air-sea fluxes of CO2 and CH4 from the Penlee Point Atmospheric Observatory on the south-west coast of the UK, Atmospheric Chemistry and Physics, 16, 5745-5761, 10.5194/acp-16-5745-2016

Yang, M., Bell, T. G., Hopkins, F. E., and Smyth, T. J.: Attribution of atmospheric sulfur dioxide over the English Channel to dimethyl sulfide and changing ship emissions, Atmospheric Chemistry and Physics, 16, 4771-4783, 10.5194/acp-16-4771-2016

Yang, M., Prytherch, J., Kozlova, E., Yelland, M. J., Parenkat Mony, D., and Bell, T. G.: Comparison of two closed-path cavity-based spectrometers for measuring air–water CO2 and CH4 fluxes by eddy covariance, Atmos. Meas. Tech., 9, 5509-5522, doi:10.5194/amt-9-5509-2016

The WCO is a partnership between Plymouth Marine Laboratory and The Marine Biological Association.