Tracing Diurnal Variations of Atmospheric CO <sub>2</sub> , O <sub>2</sub> , and δ13 ${\boldsymbol{\delta }}^{\mathbf{13}}$CO <sub>2</sub> Over a Tropical and a Temperate Forest
Abstract We analyze the diurnal variability of atmospheric , , and CO 2 above the canopies of two contrasting ecosystems: the Amazon tropical forest and the Loobos temperate forest. Using a coupled forest‐atmosphere model constrained by tower‐based and aircraft observations, we quantify the role of atmospheric processes—including entrainment, subsidence, and cloud ventilation—in shaping the diurnal amplitude, or diurnal range (DR), of carbon‐cycle tracers. Our results show that atmospheric processes can contribute more than twice as much as surface processes to DR. Misrepresenting these influences leads to substantial errors in interpreting observations and modeling tracer variability. We propose using DR as a metric to evaluate atmospheric tracer transport models and to compare site‐level measurements. We present a roadmap to identify which atmospheric or surface processes are poorly represented when modeled and observed DR diverge.
Authors
- John Bharat Miller (ORCID: https://orcid.org/0000-0001-8630-1610)
- Oscar Hartogensis (ORCID: https://orcid.org/0000-0001-8920-9975)
- Cléo Quaresma Dias‐Júnior (ORCID: https://orcid.org/0000-0003-4783-4689)
- Jordi Vilà-Guerau De Arellano (ORCID: https://orcid.org/0000-0003-0342-9171)
- Robbert Moonen
- Kim A. P. Faassen (ORCID: https://orcid.org/0000-0003-3950-0048)
- Ronald Hutjes (ORCID: https://orcid.org/0000-0002-7197-0528)
- Luiz A. T. Machado (ORCID: https://orcid.org/0000-0002-8243-1706)
- Raquel González‐Armas (ORCID: https://orcid.org/0000-0002-2922-1187)
- Thomas Röckmann (ORCID: https://orcid.org/0000-0002-6688-8968)
- Bert A. M. Kers
- B.G. Heusinkveld (ORCID: https://orcid.org/0000-0001-7844-8989)
- Wouter Mol (ORCID: https://orcid.org/0000-0003-0133-0995)
- Getachew Agmuas Adnew (ORCID: https://orcid.org/0000-0002-1999-5664)
- M. K. van der Molen (ORCID: https://orcid.org/0000-0003-4992-2420)
- Henk Snellen
- Ingrid T. Luijkx (ORCID: https://orcid.org/0000-0002-3990-6737)
- Santiago Botía (ORCID: https://orcid.org/0000-0002-5447-3968)
- Hugo J. de Boer (ORCID: https://orcid.org/0000-0002-6933-344X)
- Hella van Asperen (ORCID: https://orcid.org/0000-0002-9639-4547)
- Shujiro Komiya (ORCID: https://orcid.org/0000-0001-6185-4366)
- Gerbrand Koren (ORCID: https://orcid.org/0000-0002-2275-0713)
- Sam P. Jones (ORCID: https://orcid.org/0000-0002-6815-1601)
- Vincent S. de Feiter (ORCID: https://orcid.org/0009-0006-6363-7932)
- Lucas Hulsman (ORCID: https://orcid.org/0000-0001-5574-2106)
- Giordane Martins
Institutions
- University of Copenhagen (DK)
- National Oceanic and Atmospheric Administration (US)
- University of Groningen (NL)
- University of Applied Sciences Utrecht (NL)
- Universidade de São Paulo (BR)
- Instituto Nacional de Pesquisas da Amazônia (BR)
- Utrecht University (NL)
- Instituto Federal de Educação, Ciência e Tecnologia do Pará (BR)
- NOAA Chemical Sciences Laboratory (US)
- Max Planck Institute for Biogeochemistry (DE)
- Wageningen University & Research (NL)
Publication Details
- Journal
- Geophysical Research Letters
- Published
- 2025-10-15
- DOI
- https://doi.org/10.1029/2025gl118016
- Primary Topic
- Atmospheric and Environmental Gas Dynamics
- Type
- article
- Field-Weighted Citation Impact
- 0.00