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Paul Miller

Senior lecturer

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Characterizing Performance of Freshwater Wetland Methane Models Across Time Scales at FLUXNET-CH4 Sites Using Wavelet Analyses

Author

  • Zhen Zhang
  • Sheel Bansal
  • Kuang Yu Chang
  • Etienne Fluet-Chouinard
  • Kyle Delwiche
  • Mathias Goeckede
  • Adrian Gustafson
  • Sara Knox
  • Antti Leppänen
  • Licheng Liu
  • Jinxun Liu
  • Avni Malhotra
  • Tiina Markkanen
  • Gavin McNicol
  • Joe R. Melton
  • Paul A. Miller
  • Changhui Peng
  • Maarit Raivonen
  • William J. Riley
  • Oliver Sonnentag
  • Tuula Aalto
  • Rodrigo Vargas
  • Wenxin Zhang
  • Qing Zhu
  • Qiuan Zhu
  • Qianlai Zhuang
  • Lisamarie Windham-Myers
  • Robert B. Jackson
  • Benjamin Poulter
Show all

Summary, in English

Process-based land surface models are important tools for estimating global wetland methane (CH4) emissions and projecting their behavior across space and time. So far there are no performance assessments of model responses to drivers at multiple time scales. In this study, we apply wavelet analysis to identify the dominant time scales contributing to model uncertainty in the frequency domain. We evaluate seven wetland models at 23 eddy covariance tower sites. Our study first characterizes site-level patterns of freshwater wetland CH4 fluxes (FCH4) at different time scales. A Monte Carlo approach was developed to incorporate flux observation error to avoid misidentification of the time scales that dominate model error. Our results suggest that (a) significant model-observation disagreements are mainly at multi-day time scales (<15 days); (b) most of the models can capture the CH4 variability at monthly and seasonal time scales (>32 days) for the boreal and Arctic tundra wetland sites but have significant bias in variability at seasonal time scales for temperate and tropical/subtropical sites; (c) model errors exhibit increasing power spectrum as time scale increases, indicating that biases at time scales <5 days could contribute to persistent systematic biases on longer time scales; and (d) differences in error pattern are related to model structure (e.g., proxy of CH4 production). Our evaluation suggests the need to accurately replicate FCH4 variability, especially at short time scales, in future wetland CH4 model developments.

Department/s

  • Dept of Physical Geography and Ecosystem Science
  • LU Profile Area: Nature-based future solutions
  • LTH Profile Area: Aerosols
  • eSSENCE: The e-Science Collaboration
  • Centre for Environmental and Climate Science (CEC)
  • BECC: Biodiversity and Ecosystem services in a Changing Climate
  • MERGE: ModElling the Regional and Global Earth system

Publishing year

2023-11

Language

English

Publication/Series

Journal of Geophysical Research: Biogeosciences

Volume

128

Issue

11

Document type

Journal article

Publisher

Wiley

Topic

  • Environmental Sciences
  • Climate Research
  • Natural Sciences

Keywords

  • Methane
  • Biogeochemical models
  • wavelet analysis
  • LPJ-GUESS

Status

Published

ISBN/ISSN/Other

  • ISSN: 2169-8953