Publications [#281439] of Gabriel G. Katul
Papers Published
- Nakai, T; Katul, GG; Kotani, A; Igarashi, Y; Ohta, T; Suzuki, M; Kumagai, T, Radiative and precipitation controls on root zone soil moisture spectra,
Geophysical Research Letters, vol. 41 no. 21
(November, 2014),
pp. 7546-7554, American Geophysical Union (AGU), ISSN 0094-8276 [doi]
(last updated on 2023/06/01)Abstract:
Temporal variability in root zone soil moisture content (w) exhibits a Lorentzian spectrum with memory dictated by a damping term when forced with white-noise precipitation. In the context of regional dimming, radiation and precipitation variability are needed to reproduce w trends prompting interest in how the w memory is altered by radiative forcing. A hierarchy of models that sequentially introduce the spectrum of precipitation, net radiation, and the effect of w on evaporative and drainage losses was used to analyze the spectrum of w at subtropical and temperate forested sites. Reproducing the w spectra at long time scales necessitated simultaneous precipitation and net radiation measurements depending on site conditions. The w memory inferred from observed w spectra was 25-38 days, larger than that determined from maximum wet evapotranspiration and field capacity. The w memory can be reasonably inferred from the Lorentzian spectrum when precipitation and evapotranspiration are in phase. Key PointsClimate models predict Lorentzian temporal spectra for root zone soil moisture wLong-term site measurements deviate from Lorentzian and report shorter w memoryPrecipitation and net radiation impact w spectra and its memory at long scales