More Like this

1. Diagnosing evapotranspiration responses to water deficit across biomes using deep learning

   https://doi.org/10.1111/nph.19197  

   Giardina, Francesco; Gentine, Pierre; Konings, Alexandra G.; Seneviratne, Sonia I.; Stocker, Benjamin D. (August 2023, New Phytologist)

   Summary Accounting for water limitation is key to determining vegetation sensitivity to drought. Quantifying water limitation effects on evapotranspiration (ET) is challenged by the heterogeneity of vegetation types, climate zones and vertically along the rooting zone.Here, we train deep neural networks using flux measurements to study ET responses to progressing drought conditions. We determine a water stress factor (fET) that isolates ET reductions from effects of atmospheric aridity and other covarying drivers. We regress fET against the cumulative water deficit, which reveals the control of whole‐column moisture availability.We find a variety of ET responses to water stress. Responses range from rapid declines of fET to 10% of its water‐unlimited rate at several savannah and grassland sites, to mild fET reductions in most forests, despite substantial water deficits. Most sensitive responses are found at the most arid and warm sites.A combination of regulation of stomatal and hydraulic conductance and access to belowground water reservoirs, whether in groundwater or deep soil moisture, could explain the different behaviors observed across sites. This variety of responses is not captured by a standard land surface model, likely reflecting simplifications in its representation of belowground water storage. 

   more » « less
2. Amazonian terrestrial water balance inferred from satellite-observed water vapor isotopes

   https://doi.org/10.1038/s41467-022-30317-4  

   Shi, Mingjie; Worden, John R.; Bailey, Adriana; Noone, David; Risi, Camille; Fu, Rong; Worden, Sarah; Herman, Robert; Payne, Vivienne; Pagano, Thomas; et al (December 2022, Nature Communications)

   Abstract Atmospheric humidity and soil moisture in the Amazon forest are tightly coupled to the region’s water balance, or the difference between two moisture fluxes, evapotranspiration minus precipitation (ET-P). However, large and poorly characterized uncertainties in both fluxes, and in their difference, make it challenging to evaluate spatiotemporal variations of water balance and its dependence on ET or P. Here, we show that satellite observations of the HDO/H 2 O ratio of water vapor are sensitive to spatiotemporal variations of ET-P over the Amazon. When calibrated by basin-scale and mass-balance estimates of ET-P derived from terrestrial water storage and river discharge measurements, the isotopic data demonstrate that rainfall controls wet Amazon water balance variability, but ET becomes important in regulating water balance and its variability in the dry Amazon. Changes in the drivers of ET, such as above ground biomass, could therefore have a larger impact on soil moisture and humidity in the dry (southern and eastern) Amazon relative to the wet Amazon. 

   more » « less
3. Spatiotemporal variations of hydrochemical characteristics of irrigation water: a case study of the Lower Rio Grande Valley, USA

   https://doi.org/10.2166/ws.2023.082  

   De La Garza, Miranda Nicole; Ren, Jianhong; Ancona, Veronica (March 2023, Water Supply)

   Abstract Hydrochemical characteristics of irrigation water and their spatiotemporal variations can provide critical information for ensuring healthy crop growth and determining the best water management practices. The Lower Rio Grande Valley (LRGV) is heavily dependent upon ditch irrigation to deliver water from the Rio Grande River to support its staple crop production. To date, no studies have been conducted to quantify the water quality and its variations along the distribution system. This research measured water quality parameters at seven sites in LRGV irrigation water in 2021. Chemical indices including salinity hazard (SH), sodium adsorption ratio (SAR), sodium percentage (Na%), residual sodium carbonate (RSC), magnesium hazard (MH), Kelly's Ratio (KR), and permeability index (PI) were calculated. Classification diagrams were prepared. Results revealed the locations that had doubtful water for irrigation use and more problematic water quality index levels. June and August had the highest index levels, which may have been attributable to the large rainfall events in May and July. The SH, Na%, KR, and MH indices exceeded recommended levels. ANOVA analyses showed significant temporal variations in SAR, RSC, MH, KR, and PI. These findings indicate the importance of incorporating water quality spatiotemporal variation information in routine irrigation planning and management. 

   more » « less
4. Ice-binding site of surface-bound type III antifreeze protein partially decoupled from water

   https://doi.org/10.1039/C8CP03382J  

   Verreault, Dominique; Alamdari, Sarah; Roeters, Steven J.; Pandey, Ravindra; Pfaendtner, Jim; Weidner, Tobias (January 2018, Physical Chemistry Chemical Physics)

   Combined SFG/MD analysis together with spectral calculations revealed that type III antifreeze proteins adsorbed at the air–water interface maintains a native state and adopts an orientation that leads to a partial decoupling of its ice-binding site from water. 

   more » « less
5. Rapid, high-capacity adsorption of iodine from aqueous environments with amide functionalized covalent organic frameworks

   https://doi.org/10.1039/D3SC06004G  

   Arora, Niyati; Debnath, Tanay; Senarathna, Milinda C; Johnson, Rebecca M; Roske, Isabella G; Cisneros, G Andrés; Smaldone, Ronald A (March 2024, Chemical Science)

   Water pollution from iodine is dangerous to human health because of its long-lived radioisotopes. We show that covalent organic frameworks containing amide groups (COFamides) can quickly remove iodine from water with large adsorption capacities. 

   more » « less