Improving surface heat flux estimation for a large lake through model optimization and two-point calibration: The case of Lake Geneva

Rahaghi, Abolfazl Irani; Lemmin, Ulrich; Cimatoribus, Andrea; Bouffard, Damien; Riffler, Michael; Wunderle, Stefan; Barry, David Andrew (2018). Improving surface heat flux estimation for a large lake through model optimization and two-point calibration: The case of Lake Geneva. Limnology and oceanography: methods, 16(9), pp. 576-593. Association for the Sciences of Limnology and Oceanography 10.1002/lom3.10267

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Net Surface Heat Flux (SurHF) was estimated from 2008 to 2014 for Lake Geneva (Switzerland/France), using long-term temperature depth profiles at two locations, hourly maps of reanalysis meteorological data from a numerical weather model and lake surface water temperatures from calibrated satellite imagery. Existing formu- las for different heat flux components were combined into 54 different total SurHF models. The coefficients in these models were calibrated based on SurHF optimization. Four calibration factors characterizing the incoming long-wave radiation, sensible, and latent heat fluxes were further investigated for the six best performing models. The combination of the modified parameterization of the Brutsaert equation for incoming atmospheric radiation and of similarity theory-based bulk parameterization algorithms for latent and sensible surface heat fluxes provided the most accurate SurHF estimates. When optimized for one lake temperature profile location, SurHF models failed to predict the temperature profile at the other location due to the spatial variability of mete- orological parameters between the two locations. Consequently, the optimal SurHF models were calibrated using two profile locations. The results emphasize that even relatively small changes in calibration factors, par- ticularly in the atmospheric emissivity, significantly modify the estimated long-term heat content. The lack of calibration can produce changes in the calculated heat content that are much higher than the observed annual climate change-induced trend. The calibration improved parameterization of bulk transfer coefficients, mainly under low wind regimes.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geography > Physical Geography > Unit Remote Sensing
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geography
08 Faculty of Science > Institute of Geography > Physical Geography

UniBE Contributor:

Riffler, Michael and Wunderle, Stefan

Subjects:

500 Science > 550 Earth sciences & geology
900 History > 910 Geography & travel

ISSN:

1541-5856

Publisher:

Association for the Sciences of Limnology and Oceanography

Language:

English

Submitter:

Helga Weber

Date Deposited:

25 Sep 2018 13:33

Last Modified:

25 Sep 2018 13:42

Publisher DOI:

10.1002/lom3.10267

BORIS DOI:

10.7892/boris.120095

URI:

https://boris.unibe.ch/id/eprint/120095

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