Characterisation of cloud shadow transition signatures using a dense pyranometer network

Witthuhn, Jonas; Deneke, Hartwig; Macke, Andreas; Ritter, Oscar; Redemann, Jens; Flynn, Connor J.; Fakoya, Abdulamid A.; Lamkin, Bradley F.; Lenhardt, Emily D.; Mitchell, Logan T.; West, Emily K.; Romps, David M.; Öktem, Rusen; Kalesse-Los, Heike

doi:10.5194/acp-26-5727-2026

Articles | Volume 26, issue 8

https://doi.org/10.5194/acp-26-5727-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/acp-26-5727-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 26, issue 8

Research article

|

27 Apr 2026

Research article |

| 27 Apr 2026

Characterisation of cloud shadow transition signatures using a dense pyranometer network

Jonas Witthuhn, Hartwig Deneke, Andreas Macke, Oscar Ritter, Jens Redemann, Connor J. Flynn, Abdulamid A. Fakoya, Bradley F. Lamkin, Emily D. Lenhardt, Logan T. Mitchell, Emily K. West, David M. Romps, Rusen Öktem, and Heike Kalesse-Los

Data sets

TROPOS pyranometer network (PyrNet) observational data set collected during the S2VSR field campaign Jonas Witthuhn et al. https://doi.org/10.5439/2335684

Cloud optical properties from MFRSR Using Min Algorithm (MFRSRCLDOD1MIN) D. Zhang https://doi.org/10.5439/1027296

Total Sky Imager (TSISKYCOVER) D. Flynn and V. Morris https://doi.org/10.5439/1992207

Microwave Radiometer (MWRLOS) M. Cadeddu and M. Tuftedal https://doi.org/10.5439/1999490

Ceilometer (CEIL) D. Zhang et al. https://doi.org/10.5439/1181954

Broadband Radiometer Station (BRS) Y. Shi et al. https://doi.org/10.5439/1550918

Cloud Type Classification (CLDTYPE) D. Zhang et al. https://doi.org/10.5439/1349884

Clouds Optically Gridded by Stereo COGS product R. Oktem and D. Romps https://doi.org/10.5439/1877293

Interactive computing environment

Characterisation of cloud shadow transition signatures using a dense pyranometer network: Code, Notebooks and Datasets Jonas Witthuhn et al. https://doi.org/10.5281/zenodo.17482466

Short summary

This study examines how solar irradiance changes when sunlight passes from clear sky into cloud shadows, focusing on 3‑D radiative effects of shallow cumulus clouds. Using data from a dense pyranometer network and cloud masks from cameras we found that irradiance can rise up to 20 % above clear‑sky levels near cloud edges. Key drivers include sun‑cloud geometry and microphysical cloud properties. The results highlight the need to incorporate such 3‑D effects in atmospheric models.