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1. CO ₂ emissions from an undrained tropical peatland: Interacting influences of temperature, shading and water table depth

   https://doi.org/10.1111/gcb.14702  

   Hoyt, Alison M.; Gandois, Laure; Eri, Jangarun; Kai, Fuu Ming; Harvey, Charles F.; Cobb, Alexander R. (July 2019, Global Change Biology)

   Abstract Emission of CO₂from tropical peatlands is an important component of the global carbon budget. Over days to months, these fluxes are largely controlled by water table depth. However, the diurnal cycle is less well understood, in part, because most measurements have been collected daily at midday. We used an automated chamber system to make hourly measurements of peat surface CO₂emissions from chambers root‐cut to 30 cm. We then used these data to disentangle the relationship between temperature, water table and heterotrophic respiration (R_het). We made two central observations. First, we found strong diurnal cycles in CO₂flux and near‐surface peat temperature (<10 cm depth), both peaking at midday. The magnitude of diurnal oscillations was strongly influenced by shading and water table depth, highlighting the limitations of relying on daytime measurements and/or a single correction factor to remove daytime bias in flux measurements. Second, we found mean daily R_hethad a strong linear relationship to the depth of the water table, and under flooded conditions, R_hetwas small and constant. We used this relationship between R_hetand water table depth to estimate carbon export from both R_hetand dissolved organic carbon over the course of a year based on water table records. R_hetdominates annual carbon export, demonstrating the potential for peatland drainage to increase regional CO₂emissions. Finally, we discuss an apparent incompatibility between hourly and daily average observations of CO₂flux, water table and temperature: water table and daily average flux data suggest that CO₂is produced across the entire unsaturated peat profile, whereas temperature and hourly flux data appear to suggest that CO₂fluxes are controlled by very near surface peat. We explore how temperature‐, moisture‐ and gas transport‐related mechanisms could cause mean CO₂emissions to increase linearly with water table depth and also have a large diurnal cycle. 

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2. Time series of high-frequency meteorological data at Falling Creek Reservoir, Virginia, USA 2015-2023

   https://doi.org/10.6073/pasta/e7d9713f900d886de510906bbef1e835  

   Carey, Cayelan C; Breef-Pilz, Adrienne; Delany, Austin D (January 2024, Environmental Data Initiative)

   This dataset consists of meteorological variables measured by a research-grade Campbell Scientific meteorological station deployed on the dam of Falling Creek Reservoir (37.3025, -79.83667). Falling Creek Reservoir (Vinton, Virginia, USA), is owned and operated by the Western Virginia Water Authority as a primary water source. The meteorological variables include photosynthetic active radiation, barometric pressure, ambient air temperature, relative humidity, rainfall, wind speed and direction, shortwave radiation, infrared radiation, and albedo. All variables were measured every 5 minutes from 2015-07-07 15:45:00 to 2015-07-13 11:28:00 (YYYY-MM-DD hh:mm:ss) and every minute thereafter to the end of the dataset at 2023-12-31 23:59:00. We applied substantial quality assurance/quality control protocols to the raw observations, as described in the methods. 

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3. Time series of high-frequency meteorological data at Falling Creek Reservoir, Virginia, USA 2015-2022

   https://doi.org/10.6073/pasta/f3f97c7fdd287c29084bf52fc759a801  

   Carey, Cayelan C.; Breef-Pilz, Adrienne (February 2023, Environmental Data Initiative)

   This dataset consists of meteorological variables measured by a research-grade Campbell Scientific meteorological station deployed on the dam of Falling Creek Reservoir. Falling Creek Reservoir (Vinton, Virginia, USA), is owned and operated by the Western Virginia Water Authority as a primary water source. The meteorological variables include photosynthetic active radiation, barometric pressure, ambient air temperature, relative humidity, rainfall, wind speed and direction, shortwave radiation, infrared radiation, and albedo. All variables were measured every 5 minutes from 2015-07-07 16:45:00 to 2015-07-13 12:20:00 (YYYY-MM-DD hh:mm:ss) and every minute thereafter to the end of the dataset at 2022-12-31 23:59:00. We applied substantial quality assurance/quality control protocols to the raw observations, as described in the methods. 

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4. Time series of high-frequency meteorological data at Falling Creek Reservoir, Virginia, USA 2015-2024

   https://doi.org/10.6073/pasta/0389840ddcb39ec5526869ac898ddb5d  

   Carey, Cayelan C; Breef-Pilz, Adrienne (January 2025, Environmental Data Initiative)

   This dataset consists of meteorological variables measured by a research-grade Campbell Scientific meteorological station deployed on the dam of Falling Creek Reservoir (37.3025, -79.83667). Falling Creek Reservoir (Vinton, Virginia, USA), is owned and operated by the Western Virginia Water Authority as a primary water source. The meteorological variables include photosynthetic active radiation, barometric pressure, ambient air temperature, relative humidity, rainfall, wind speed and direction, shortwave radiation, infrared radiation, and albedo. All variables were measured every 5 minutes from 2015-07-07 15:45:00 to 2015-07-13 11:28:00 (YYYY-MM-DD hh:mm:ss) and every minute thereafter to the end of the dataset at 2024-12-31 23:59:00. We applied substantial quality assurance/quality control protocols to the raw observations, as described in the methods. 

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5. Evaluating the temporal capability of empirical climatologies for rapid long-range volcanic infrasound propagation estimates using a multidecadal data set of persistent Vanuatu volcanic eruptions

   https://doi.org/10.1093/gji/ggaf027  

   De Negri, Rodrigo_S; Matoza, Robin_S; Hupe, Patrick; Le Pichon, Alexis; Rose, Kaelynn_M; Cevuard, Sandrine; Niroa, John_J (January 2025, Geophysical Journal International)

   SUMMARY Powerful infrasound (acoustic waves $$\lt $$20 Hz) can be produced by explosive volcanic eruptions. The long-range propagation capability, over hundreds to thousands of kilometers, of atmospheric infrasound motivates the development of regional or even global scale volcano-infrasound monitoring systems. Infrasound propagation paths are subject to spatiotemporal atmospheric dynamics, which lead to deviations in the direction-of-arrival (back-azimuth) observed at sensor arrays and contribute to source location uncertainty. Here, we further investigate the utility of empirical climatologies combined with 3-D ray tracing for providing first-order estimates of infrasound propagation paths and back-azimuth deviation corrections. The intended application is in scenarios requiring rapid or pre-computed infrasound propagation calculations, such as for a volcano-infrasound monitoring system. Empirical climatologies are global observationally based function fitting models of the atmosphere, representing robust predictors of the bulk diurnal to seasonal atmospheric variability. Infrasound propagation characteristics have previously been shown to have strong seasonal and diurnal components. At the International Monitoring System infrasound station IS22, New Caledonia, quasi-continuous multiyear infrasound array detections show oscillating azimuthal variations for arrivals from volcanoes in Vanuatu, including Yasur ($$\sim$$400 km range), Ambrym ($$\sim$$670 km range) and Lopevi ($$\sim$$650 km range). We perform 3-D ray tracing to model infrasound propagation from the Ambrym and Yasur volcano locations to IS22 every six hours (00:00, 06:00, 12:00 and 18:00 UTC) for every day of 2004 and 2019 for Ambrym and Yasur, respectively and evaluate the results as compared to the multiyear observations. We assess a variety of models and parametrizations, including both empirical climatologies and hybrid descriptions; range-independent and range-dependent atmospheric discretizations; and unperturbed and perturbed range-independent empirical climatologies. The hybrid atmospheric descriptions are composed of fifth generation reanalysis descriptions (ERA 5) from the European Centre for Medium-Range Weather Forecasts below $$\sim$$80 km altitude combined with empirical climatologies above. We propose and employ simple parametric perturbations to the empirical climatologies, which are designed to enhance the stratospheric duct and compensate for missing gravity wave perturbations not included in the climatologies, and thereby better match observations. We build year-long back-azimuth deviation interpolations from the simulations and compare them with three different multiyear array detection data sets from IS22 covering from 2003 up to 2022. Through a systematic comparison, we find that the range-independent empirical climatologies can capture bulk azimuth deviation variability and could thus be useful for rapid infrasound propagation calculation scenarios, particularly during favourable sustained propagation ducting conditions. We show that the hybrid models better describe infrasound propagation during periods of weak stratospheric ducting and during transient atmospheric changes such as stratospheric wind reversals. Overall, our results support the notion that climatologies, if perturbed to compensate for missing gravity wave structure, can improve rapid low-latency and pre-computed infrasound source discrimination and location procedures. 

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