Known Issues

Known Issues#

USTAR Detection#

Siginificantly changed threshold after 2015 in FLUXNET analysis#

  • FLUXNET uses a sophisticated approach to detect USTAR thresholds across years

  • The method is described in Pastorello et al., 2020

  • In case of CH-LAE, the detected thresholds change significantly after 2015 Fig.

  • At the moment, the cause of this change is unknown

  • However, it coincides with a setup change:

    • IRGA measurements were done completely with an open-path LI-7500 until 11 Jan 2016 (Phase 1, P1)

    • After that, a close-path LI-7200 was installed and run in parallel until 12 Dec 2017 (P2)

    • Starting on 14 Dec 2017, only the LI-7200 was installed (P3)

  • This means the USTAR detection was done using the LI-7500 during P1.

  • NEE that was used during P1 was corrected for self-heating, similar to the approach by Kittler et al., 2017

Fig. 1 Results from the FLUXNET USTAR threshold detection, based on data 2004-2023.#

_images/USTAR_thresholds_from_FLUXNET_NEE_VUT_2004-2023.png

Fig. 2 This is a caption in Markdown!#

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