Article
Engineering, Civil
Conrad Wasko, Yawen Shao, Elisabeth Vogel, Louise Wilson, Q. J. Wang, Andrew Frost, Chantal Donnelly
Summary: Changes in the hydrologic cycle have significant impacts on agricultural productivity, water resources availability, and environmental management in Australia. While northern parts of Australia have experienced increasing rainfall and water availability, the southwest and southeast coast have seen declines in rainfall, affecting runoff and soil moisture. Standardised runoff index indicates increasing streamflow droughts across large parts of Australia.
JOURNAL OF HYDROLOGY
(2021)
Article
Engineering, Civil
Conrad Wasko, Rory Nathan, Lina Stein, Declan O'Shea
Summary: Increases in extreme rainfall intensities due to climate change may lead to increased risk of pluvial flooding, especially in urban areas. However, these increases in extreme rainfall do not always result in universal increases in flooding, and the trends vary across different regions. The study finds that while rainfall intensity is intensifying, the magnitude of frequent floods is generally decreasing, particularly in tropical and arid regions, while the magnitude of rarer floods is increasing.
JOURNAL OF HYDROLOGY
(2021)
Article
Environmental Sciences
Yi Liu, Ye Zhu, Liliang Ren, Vijay P. Singh, Shanshui Yuan
Summary: Flash drought refers to a short-duration but impactful drought event. This study analyzed data from China between 1950 and 2021 and found that the flash drought signal gradually attenuates as the time scale increases. Most flash drought events evolve into conventional drought before dissipating completely.
ENVIRONMENTAL RESEARCH LETTERS
(2023)
Article
Environmental Sciences
A. L. Kay, R. A. Lane, V. A. Bell
Summary: This study simulates soil moisture content in the UK using a hydrological model and compares the results with observation-based data. It finds good correspondence in soil drying and wetting dates and the month when soils are driest. The study also uses regional projections to investigate future changes in soil moisture, showing an increase in low soil moisture levels and later soil wetting dates.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Vimal Mishra, Saran Aadhar, Shanti Shwarup Mahto
Summary: Flash droughts lead to rapid soil moisture depletion, causing significant impacts on crop health and irrigation demands. Research shows that flash droughts in India mainly occur during the summer monsoon season, driven by intraseasonal variability of monsoon rainfall. In the future, the risk of flash droughts is expected to increase due to climate change and anthropogenic warming.
NPJ CLIMATE AND ATMOSPHERIC SCIENCE
(2021)
Article
Engineering, Civil
Paolo Filippucci, Luca Brocca, Christian Massari, Carla Saltalippi, Wolfgang Wagner, Angelica Tarpanelli
Summary: Rainfall monitoring is crucial for various hydrological applications. While in-situ measurements have limitations, satellite products like SM2RAIN show promise. This study explores the self-calibration of SM2RAIN using ASCAT soil moisture data, with promising results for rainfall estimation.
JOURNAL OF HYDROLOGY
(2021)
Article
Engineering, Civil
J. Martinez-Fernandez, A. Gonzalez-Zamora, L. Almendra-Martin
Summary: Understanding the dynamics of soil moisture memory (SMM) is crucial, with soil texture playing a key role and organic matter content showing a strong relationship with the stored precipitation fraction (F-p). The study highlights the importance of precise characterization of water storage conditions, especially in terms of texture and organic matter content, in understanding SMM dynamics.
JOURNAL OF HYDROLOGY
(2021)
Article
Environmental Sciences
J. Y. Song, P. Abbaszadeh, P. Deb, H. Moradkhani
Summary: This study examines the coincidence of agricultural droughts and tropical storms in the contiguous United States, and evaluates the impact of tropical storms on drought mitigation. High-resolution soil moisture data and hurricane database are used to analyze the offset of drought conditions. The findings provide valuable information for mitigating drought and tropical storms in the future.
Article
Geosciences, Multidisciplinary
Yarong Sun, Chao Liu, Min Zhao, Le Liu, Siqi Liang, Yajuan Wang, Yunming Chen
Summary: Extreme rainfall events can significantly impact soil carbon release, leading to increased CO2 emissions from deep soil and affecting regional carbon emissions.
Article
Geosciences, Multidisciplinary
Alexandre Tuel, Bettina Schaefli, Jakob Zscheischler, Olivia Martius
Summary: River discharge is significantly influenced by the temporal clustering of extreme precipitation events. Clustered events result in a longer and greater response in discharge compared to isolated events. The probability of exceeding the 95th discharge percentile within 5 days following extreme precipitation is up to twice as high for clustered events. The impact of clustering decreases as the time window increases, and is also affected by catchment area, streamflow regime and precipitation magnitude. Additionally, persistent periods of high discharge often coincide with temporal clusters of precipitation extremes.
HYDROLOGY AND EARTH SYSTEM SCIENCES
(2022)
Article
Environmental Sciences
Ying Zhang, Jinliang Hou, Chunlin Huang
Summary: Precipitation monitoring is crucial for earth system modeling and environmental management. Traditional gauge measurements and satellite-derived rainfall have limitations in spatial representativeness and resolution. This study proposes an integration framework using multiple soil moisture datasets and machine learning methods to improve the accuracy of rainfall estimation, resulting in a successful rainfall product.
Article
Engineering, Civil
Yao Lai, Jie Tian, Weiming Kang, Chao Gao, Weijie Hong, Chansheng He
Summary: Rainfall estimation in mountainous areas is crucial for water supply and ecosystem services in arid regions. Traditional rain gauge measurements are limited in mountainous areas, while satellite and reanalysis products often have high uncertainty at high elevations. A novel bottom-up approach called SM2RAIN, which estimates rainfall from soil moisture dynamics, shows potential as an alternative method. This study evaluates the performance of SM2RAIN in high-altitude mountainous areas using data from 9 observation stations in the Qilian Mountains. The results highlight the strengths and limitations of SM2RAIN, and suggest that calibration using high-resolution soil moisture data and bias-correction methods can improve its accuracy in data-scarce mountainous regions.
JOURNAL OF HYDROLOGY
(2022)
Article
Engineering, Geological
Zonglin Zhang, Runqiang Zeng, Xingmin Meng, Shufen Zhao, Jianhua Ma, Hong Wang, Xiangpei Meng, Hailong Yin, Yunqi Yao, Weiwei Guo, Dengju Xie, Bin He
Summary: This study explores the factors controlling differential soil actual evaporation at different parts of a slope. It discovers the impact of historical rainfall on soil erosion, which leads to significant differences in soil moisture and evaporation at different locations on the slope.
ENGINEERING GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Minu Treesa Abraham, Neelima Satyam, Ascanio Rosi, Biswajeet Pradhan, Samuele Segoni
Summary: Empirical and probabilistic approaches for defining rainfall thresholds are commonly used for forecasting rainfall induced landslides, but often result in higher false alarms. This study aims to improve the performance of conventional meteorological thresholds by considering the effect of soil moisture, using a probabilistic approach. Results show that a Bayesian probabilistic threshold derived using rainfall severity and soil wetness outperformed the conventional approaches, with potential for developing an operational landslide early warning system based on a combination of rainfall and soil moisture data.
Article
Agronomy
Ziqi Liu, Kaiping Li, Kangning Xiong, Yuan Li, Jin Wang, Jian Sun, Lulu Cai
Summary: The study demonstrates that cultivating Zanthoxylum bungeanum in karst areas can improve the shallow soil hydraulic properties and have a positive impact on water conservation. The dynamic change in soil moisture is influenced by precipitation and atmospheric temperature, with the impact increasing with the time since planting. Therefore, planting Zanthoxylum bungeanum can improve soil water retention capacity and stability, benefiting water resource management in karst areas.
AGRICULTURAL WATER MANAGEMENT
(2021)
Article
Meteorology & Atmospheric Sciences
Marc Calaf, Nikki Vercauteren, Gabriel G. Katul, Marco G. Giometto, Travis J. Morrison, Fabien Margairaz, Vyacheslav Boyko, Eric R. Pardyjak
Summary: The time integration of the unsteady Reynolds-averaged Navier-Stokes equations is widely used in numerical weather prediction. This approach divides the flow into an ensemble mean and turbulence-related fluctuations, allowing closure schemes to describe their statistical properties. However, modelling challenges arise when unresolved fluctuations include non-turbulent structured motions, which can render conventional closure schemes ineffective. This study seeks to address these challenges by discussing theoretical tactics and considering the use of large-eddy simulations, direct numerical simulations, and field measurements.
BOUNDARY-LAYER METEOROLOGY
(2023)
Article
Meteorology & Atmospheric Sciences
Michael Heisel, Peter P. Sullivan, Gabriel G. Katul, Marcelo Chamecki
Summary: A persistent spatial organization of eddies has been identified in the lowest part of the stably stratified planetary boundary layer. The coherent turbulent structure is approximated as a series of uniform momentum zones and uniform temperature zones separated by thin layers of intense gradients. The study also reveals that the size of the eddies decreases with increasing stratification, which results in deviations from the logarithmic mean profiles for velocity and temperature.
BOUNDARY-LAYER METEOROLOGY
(2023)
Article
Mechanics
Luca Mortarini, Gabriel G. Katul, Daniela Cava, Cleo Quaresma Dias-Junior, Nelson Luis Dias, Antonio Manzi, Matthias Sorgel, Alessandro Araujo, Marcelo Chamecki
Summary: This study derives a dimensionless correction function Phi(RSL)(z/h) for the law of the wall using atmospheric turbulence measurements in the Amazon. The relationship between the vertical velocity spectrum E-ww(k) and Phi(RSL) is established using a co-spectral budget model. The findings show that /RSL is determined by the ratio of two turbulent viscosities.
Article
Agronomy
Zhiyong Wu, John T. Walker, Christopher Oishi, Tomer Duman, Gabriel Katul, Xi Chen, Donna Schwede, Jesse Bash, John Iiames
Summary: This study used inverse modeling methods to estimate the source-sink and flux profiles of reactive nitrogen (N) and sulfur (S) compounds at a forest site in the southern Appalachian Mountains. The findings show that crown foliage dominates the uptake of reactive N and S during the growing season, accounting for 80-90% of the total canopy-scale flux. The study highlights the need for improved parameterizations of litter exchange and NH3 compensation points in resistance models for forest ecosystems.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Geosciences, Multidisciplinary
O. Crompton, G. Katul, D. Lapides, S. Thompson
Summary: In drylands, runoff redistribution during storms from bare soil areas to vegetated patches is important for vegetation growth. The interaction of surface roughness and permeability determines the extent of this redistribution. Virtual experiments and the use of the 2D Saint Venant Equations were employed to measure runoff connectivity and identify landscapes likely to shed water.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Mechanics
Mazen Nakad, Jean-Christophe Domec, Sanna Sevanto, Gabriel Katul
Summary: In plants, the transport of photosynthesis products is achieved through a hydraulic system called phloem. This study develops a new numerical model to investigate osmotically driven flows in phloem. The results show that the hydrodynamic and geometrical characteristics of phloem significantly affect the speed of sucrose transport, providing a novel perspective on the evolutionary adaptation of plant hydraulic traits for efficient transport of soluble compounds.
Article
Environmental Sciences
Kelly Y. Y. Huang, Gabriel G. G. Katul, Thomas J. J. Hintz, Jesus Ruiz-Plancarte, Qing Wang, Harindra J. S. Fernando
Summary: The study investigates the intermittency of fog by analyzing the visibility time series collected in July 2022 on Sable Island, Canada. It is found that relative humidity and turbulent kinetic energy are related to various stochastic features of visibility.
Editorial Material
Environmental Sciences
Gabriel G. Katul
Summary: Agrivoltaics (AV) offers a solution to the competition between solar energy generation and crop production for arable land. By utilizing excess light for energy production, the efficiency of photosynthesis can be maximized. A numerical model was developed to predict photosynthesis, stomatal conductance, and transpiration. This commentary discusses the implications of these findings for aboveground biomass and plant micro-environment modifications.
Article
Environmental Sciences
Mazen Nakad, Jean-Christophe Domec, Sanna Sevanto, Gabriel Katul
Summary: The hydrodynamics of phloem plays a crucial role in plant survival and ecosystem-scale carbon and water cycling. The phloem transports products of photosynthesis throughout the plant and is mathematically represented by the Mu'' $\ddot{u}$nch pressure flow hypothesis (PFH). However, this framework does not take into account the elasticity of living phloem cells, which has been shown to affect the speed of sucrose diffusion.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Environmental Sciences
Yuanyuan Gu, Gabriel G. G. Katul, Nicolas Cassar
Summary: The global air-sea CO2 flux (F) is influenced and influenced by various climate-related processes operating at different time scales. Factors such as the air-sea partial pressure difference, gas transfer velocity, sea surface temperature, and salinity drive the variability in F at different time scales. Wind speed variability is the dominant driver on subseasonal scales, while the increment pCO(2) effect is the main driver on seasonal, interannual, and decadal scales, particularly in high latitudes. The increment pCO(2) effect is closely linked to the relative strength of atmospheric pCO(2) and the nonthermal component of oceanic pCO(2) anomaly associated with dissolved inorganic carbon and alkalinity.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Agronomy
Milan Fischer, Gabriel Katul, Asko Noormets, Gabriela Poznikova, Jean-Christophe Domec, Matej Orsag, Zdenek Zalud, Miroslav Trnka, John S. King
Summary: This study tested the reliability of two micrometeorological methods using high-frequency sampled air temperature in different agricultural systems and compared them with eddy covariance measurements. The results showed that the most reliable methods accurately estimated sensible heat flux and performed the best in agricultural systems.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Geosciences, Multidisciplinary
Octavia Crompton, Gabriel Katul, Dana A. Lapides, Sally E. Thompson
Summary: On dryland hillslopes, vegetation water availability is subsidized through the redistribution of rainfall runoff from bare soil to vegetation patches. The connectivity within bare soil areas plays a crucial role in the establishment and persistence of dryland ecosystems. Inferring functional connectivity from structural landscape features is an attractive approach, but the relationship between the two remains uncertain and requires further exploration.
Article
Thermodynamics
Kelly Y. Huang, Matt K. Fu, Clayton P. Byers, Andrew D. Bragg, Gabriel G. Katul
Summary: A generalized logarithmic law for high-order moments of homogeneous passive scalars is proposed for turbulent boundary layers. The theory predicts logarithmic variations of high-order moments within the inertial sublayer, and it is evaluated using high frequency time-series measurements of temperature and streamwise velocity fluctuations. The proposed theory appears to be as, if not more, valid for transported passive scalars than for the longitudinal velocity.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2023)
Article
Geography, Physical
Taro Nakai, Tetsuya Hiyama, Ayumi Kotani, Yoshihiro Iijima, Takeshi Ohta, Trofim C. Maximov
Summary: A simple stochastic representation of spatial variability in thaw depth was proposed in this study. Thaw depth distribution in two larch-type forests in eastern Siberia, Spasskaya Pad and Elgeeii, exhibited different spatial, seasonal, and interannual variability. The year-to-year variation in active-layer thickness was minimal in Spasskaya Pad compared to Elgeeii. The gamma distribution was found to adequately represent the spatial variability in thaw depth at both sites. A simple model using the gamma distribution was developed to illustrate the spatial variability in thaw depth at any thawing stage based on a given mean thaw depth.
PERMAFROST AND PERIGLACIAL PROCESSES
(2023)
Review
Forestry
Mazen Nakad, Sanna Sevanto, Jean-Christophe Domec, Gabriel Katul
Summary: This review examines how woody species adapt to harsh abiotic conditions by using simplified stomatal optimization theories to assess the response of photosynthesis and transpiration to warming, drought, and combined warming and drought stressors. The results demonstrate that different species' acclimation behaviors can be explained by deviations between measurements and predictions from the simplified optimality principle.
CURRENT FORESTRY REPORTS
(2023)