Article
Meteorology & Atmospheric Sciences
Kevin Schwarzwald, Andrew Poppick, Maria Rugenstein, Jonah Bloch-Johnson, Jiali Wang, David McInerney, Elisabeth J. Moyer
Summary: Changes in precipitation variability may increase more steeply than its mean in future climate projections, leading to concerns about societal impacts. At local scales, changes in precipitation distributions are complex, while at aggregated scales they become simpler. Precipitation variability changes are especially concerning in subtropical regions.
JOURNAL OF CLIMATE
(2021)
Article
Water Resources
Hanbeen Kim, Gabriele Villarini
Summary: This study examines the potential applicability of weather types as predictors of flood extremes. While there is a statistical relationship between weather types and the major climate drivers of flooding, the frequencies of weather types have limited skill in predicting the interannual variability of peak discharge.
HYDROLOGICAL PROCESSES
(2023)
Article
Environmental Sciences
Shouliang Huo, Chunzi Ma, Wenpan Li, Zhuoshi He, Hanxiao Zhang, Le Yu, Yong Liu, Xianghui Cao, Fengchang Wu
Summary: The increase in nutrient loadings in China's waterways over the past four decades has led to widespread eutrophication and water quality impairments. This study provides estimates of changes in riverine nutrient fluxes for China from 1980 to 2018 and reveals significant spatial, interannual, and long-term variations. The study emphasizes the important role of precipitation and temperature variability in controlling nutrient fluxes.
Article
Meteorology & Atmospheric Sciences
Sharon E. Nicholson, Douglas Klotter
Summary: This study compares the characteristics of the Tropical Easterly Jet (TEJ) and upper-level winds in six reanalysis products, shows that CFSR and 20th Century Reanalysis overestimate wind speeds compared to other reanalyses, and suggests that changes in TEJ are not forced by rainfall but driven by large-scale factors. Potential mechanisms for a causal relationship between TEJ strength and high rainfall are discussed, with additional modeling efforts needed to determine the exact connection between TEJ and Sahel rainfall.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Wei Wei, Qiaoling Ren, Mengmeng Lu, Song Yang
Summary: The investigation reveals a close relationship between the interannual variation of the Middle East jet stream (MEJS) and a wetter and colder winter in southern China, as well as a later onset of the subsequent Asian summer monsoon. The MEJS extends eastward, resulting in the formation of an anomalous anticyclone over the Arabian Sea and increased convection over the western tropical Indian Ocean. This positive feedback loop intensifies the MEJS extension and affects the weather patterns in subtropical Eurasia.
JOURNAL OF CLIMATE
(2022)
Article
Engineering, Civil
N. O. Agutu, C. E. Ndehedehe, J. L. Awange, F. Kirimi, M. Mwaniki
Summary: This study evaluated the uncertainty of soil moisture products from various LSMs over Greater Horn of Africa, revealing higher uncertainties in areas of high rainfall and complex topographical characteristics. MERRA2 and ERA5 consistently showed lower uncertainties compared to CPC. Interannual variability analyses also showed differences in uncertainties between wet and dry seasons across different regions within GHA. The results contribute to understanding the uncertainty levels and suitability of LSM-derived soil moisture products in the region.
JOURNAL OF HYDROLOGY
(2021)
Article
Multidisciplinary Sciences
Rei Chemke, Janni Yuval
Summary: The Hadley circulation plays a crucial role in determining precipitation and temperature patterns at low latitudes. However, there is currently a large uncertainty in the recent changes of the Hadley circulation in the Northern Hemisphere. This study demonstrates that the circulation has considerably weakened over recent decades and attributes the weakening to anthropogenic emissions, which enhances our confidence in projections of tropical climate change caused by human activities.
Article
Meteorology & Atmospheric Sciences
D. M. Morake, R. C. Blamey, C. J. C. Reason
Summary: The climatology of large, long-lived mesoscale convective systems (MCSs) over eastern South Africa during the extended austral summer from 1985 to 2008 shows an average of 63 MCSs occurring in summer with considerable interannual variability. These systems mainly occur between November and March, with a peak in December, and are influenced by favorable CAPE and vertical shear profiles.
JOURNAL OF CLIMATE
(2021)
Article
Environmental Sciences
Panxing He, Xiaoliang Ma, Zongjiu Sun
Summary: Interannual variability in climate change is the key environmental factor controlling the seasonality and long-term variation of vegetation growth.
ENVIRONMENTAL RESEARCH
(2022)
Article
Multidisciplinary Sciences
Jasper Verschuur, Sihan Li, Piotr Wolski, Friederike E. L. Otto
Summary: The food crisis in Lesotho in 2007, exacerbated by climate change, highlighted the impact of climate change on food security. The study found that a fragile agricultural system combined with trade dependency on a climatically connected partner can lead to a nonlinear response to climate change.
SCIENTIFIC REPORTS
(2021)
Article
Meteorology & Atmospheric Sciences
Hanjie Fan, Bohua Huang, Song Yang, Wenjie Dong
Summary: The study reveals that the Pacific meridional mode has a significant influence on the development of El Nino-Southern Oscillation events and their seasonal predictability. A matched PMM forcing enhances ENSO events, while a mismatched PMM forcing has a damping effect. The PMM acts as a modulator, rather than a trigger, for ENSO events, and its influence is modulated by the preconditioning of the upper-ocean heat content.
JOURNAL OF CLIMATE
(2021)
Article
Meteorology & Atmospheric Sciences
Jiwoo Lee, Kenneth R. Sperber, Peter J. Gleckler, Karl E. Taylor, Celine J. W. Bonfils
Summary: We evaluated improvements in extratropical modes of variability in climate models through CMIP3, CMIP5, and CMIP6 phases, finding that newer models show significant improvement in simulating spatial patterns of these modes, though varied in amplitude and seasonal performance. Identified errors in postdominant season amplitude in models suggest a need for continued refinement.
JOURNAL OF CLIMATE
(2021)
Article
Environmental Sciences
Raul R. Wood, Flavio Lehner, Angeline G. Pendergrass, Sarah Schlunegger
Summary: Anthropogenic changes in precipitation variability have significant impacts on natural and human systems. Understanding changes in precipitation variability, mean and extreme precipitation is crucial for unraveling the hydrological cycle's response to warming. State-of-the-art climate models show consistent scaling rates of precipitation variability across different timescales, with increased precipitation likely in mid- and high latitudes. Model uncertainties are prevalent, especially in the Tropics and Subtropics, highlighting the importance of accurate representation of full precipitation distribution.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Miaomiao Wang, Jian Zhao, Shaoqiang Wang, Bin Chen
Summary: This study used remote sensing and diagnostic models to investigate the interannual variability of net ecosystem production (NEP) on a global scale from 1982 to 2016. The study found that NEP has large interannual variability globally, with temperature being the most critical factor influencing NEP.
Article
Meteorology & Atmospheric Sciences
Masilin Gudoshava, Caroline Wainwright, Linda Hirons, Hussen S. Endris, Zewdu T. Segele, Steve Woolnough, Zachary Atheru, Guleid Artan
Summary: The timing of the rainy season is crucial for various sectors in Eastern Africa. Early onset is associated with increased rainfall and warmer sea surface temperatures, while late onset is associated with rainfall deficit and cooler sea surface temperatures. The variability in onset date is influenced by Indian Ocean sea surface temperatures and circulation.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Multidisciplinary Sciences
Christopher A. Williams, Huan Gu, Tong Jiao
Summary: The study finds that forest loss in different regions of the United States has varying effects on the climate, impacting the magnitude of global climate change. Forest conversions may initially lead to temporary net cooling, but over the long term can transition to net warming, posing challenges in offsetting the climate warming effects of fossil fuel emissions.
Article
Environmental Sciences
C. Wade Ross, Niall P. Hanan, Lara Prihodko, Julius Anchang, Wenjie Ji, Qiuyan Yu
Summary: This study explores the socioenvironmental conditions shaping the distribution of woody vegetation in sub-Saharan Africa and evaluates ecosystem responses to various scenarios. Climate change is projected to have a negative impact on above-ground woody biomass, exacerbated by population growth, human pressures, and changes in fire behavior. Regional perturbations show increased carbon storage potential in East Africa, while deficits are seen in West, Central, and Southern Africa.
NATURE CLIMATE CHANGE
(2021)
Article
Multidisciplinary Sciences
Lei Hu, Stephen A. Montzka, Aleya Kaushik, Arlyn E. Andrews, Colm Sweeney, John Miller, Ian T. Baker, Scott Denning, Elliott Campbell, Yoichi P. Shiga, Pieter Tans, M. Carolina Siso, Molly Crotwell, Kathryn McKain, Kirk Thoning, Bradley Hall, Isaac Vimont, James W. Elkins, Mary E. Whelan, Parvadha Suntharalingam
Summary: In the Arctic and Boreal region, the increase of gross primary production (GPP) has been suggested as an important driver for the increase of the atmospheric CO2 seasonal cycle amplitude (SCA). By using atmospheric carbonyl sulfide (COS) measurements, this study provides observation-based estimates of GPP in North American ABR, showing that GPP likely exceeded ecosystem respiration increases in the past four decades. However, in autumn, increases of ecosystem respiration were likely greater than GPP increases, contributing to autumn net carbon emissions.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Meteorology & Atmospheric Sciences
Sarah M. Gallup, Ian T. Baker, John L. Gallup, Natalia Restrepo-Coupe, Katherine D. Haynes, Nicholas M. Geyer, A. Scott Denning
Summary: Estimates of Amazon rainforest gross primary productivity (GPP) vary significantly among different models, which adds uncertainty to future climate predictions. Models with stronger seasonal swings in GPP have stronger responses to climate drivers than observed in actual data.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2021)
Article
Ecology
Andrew M. Cunliffe, Karen Anderson, Fabio Boschetti, Richard E. Brazier, Hugh A. Graham, Isla H. Myers-Smith, Thomas Astor, Matthias M. Boer, Leonor G. Calvo, Patrick E. Clark, Michael D. Cramer, Miguel S. Encinas-Lara, Stephen M. Escarzaga, Jose M. Fernandez-Guisuraga, Adrian G. Fisher, Katerina Gdulova, Breahna M. Gillespie, Anne Griebel, Niall P. Hanan, Muhammad S. Hanggito, Stefan Haselberger, Caroline A. Havrilla, Phil Heilman, Wenjie Ji, Jason W. Karl, Mario Kirchhoff, Sabine Kraushaar, Mitchell B. Lyons, Irene Marzolff, Marguerite E. Mauritz, Cameron D. McIntire, Daniel Metzen, Luis A. Mendez-Barroso, Simon C. Power, Jiri Prosek, Enoc Sanz-Ablanedo, Katherine J. Sauer, Damian Schulze-Bruninghoff, Petra Simova, Stephen Sitch, Julian L. Smit, Caiti M. Steele, Susana Suarez-Seoane, Sergio A. Vargas, Miguel Villarreal, Fleur Visser, Michael Wachendorf, Hannes Wirnsberger, Robert Wojcikiewicz
Summary: This study developed a new protocol for photogrammetric height using UAV images to standardized measurements of biomass across a globally distributed field experiment. Canopy height inferred from UAV photogrammetry was found to strongly predict aboveground biomass across different plant species, providing accurate estimates. The photogrammetric approach proved to be sensitive to wind speed but robust in providing generalizable measurements across different growth forms and environments, demonstrating its potential for accurately estimating biomass in various ecosystems.
REMOTE SENSING IN ECOLOGY AND CONSERVATION
(2022)
Article
Plant Sciences
Brianna M. Lind, Paul Eggleton, Vivienne M. Uys, Niall P. Hanan
Summary: Termite feeding groups in southern Africa vary across the rainfall gradient, with FG-IIw termites being dominant. Precipitation influences the species diversity of feeding groups and causes notable shifts in termite community structure. Termites are likely to play a significant role in plant material decomposition in southern Africa.
Editorial Material
Multidisciplinary Sciences
Niall P. Hanan, Anthony M. Swemmer
Summary: An analysis of carbon stored in plants and soil in an African savannah suggests that frequent fires may have less impact on atmospheric carbon dioxide concentrations and global warming than previously thought.
Article
Multidisciplinary Sciences
Zutao Ouyang, Pietro Sciusco, Tong Jiao, Sarah Feron, Cheyenne Lei, Fei Li, Ranjeet John, Peilei Fan, Xia Li, Christopher A. Williams, Guangzhao Chen, Chenghao Wang, Jiquan Chen
Summary: The replacement of natural lands with urban structures has led to a decrease in albedo, contributing to global warming. Future urban land expansion without proper mitigation will further exacerbate this effect.
NATURE COMMUNICATIONS
(2022)
Article
Environmental Sciences
Guillermo Murray-Tortarolo, Benjamin Poulter, Rodrigo Vargas, Daniel Hayes, Anna M. Michalak, Christopher Williams, Lisamarie Windham-Myers, Jonathan A. Wang, Kimberly P. Wickland, David Butman, Hanqin Tian, Stephen Sitch, Pierre Friedlingstein, Mike O'Sullivan, Peter Briggs, Vivek Arora, Danica Lombardozzi, Atul K. Jain, Wenping Yuan, Roland Seferian, Julia Nabel, Andy Wiltshire, Almut Arneth, Sebastian Lienert, Sonke Zaehle, Vladislav Bastrikov, Daniel Goll, Nicolas Vuichard, Anthony Walker, Etsushi Kato, Xu Yue, Zhen Zhang, Abhishek Chaterjee, Werner Kurz
Summary: Continental North America has been a carbon sink over recent decades, driven by vegetation absorption capacity and C losses due to fire. Drought years have the potential to shift the region to a small net C source.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2022)
Article
Biodiversity Conservation
Enqing Hou, Shuang Ma, Yuanyuan Huang, Yu Zhou, Hyung-Sub Kim, Efren Lopez-Blanco, Lifen Jiang, Jianyang Xia, Feng Tao, Christopher Williams, Mathew Williams, Daniel Ricciuto, Paul J. Hanson, Yiqi Luo
Summary: This study used a matrix approach to analyze the differences in simulating land carbon dynamics between different models and identify their sources. The study found that the differences between models mainly came from differences in baseline carbon residence time and environmental factors, and these differences can be reduced by standardizing model parameters. The findings of this study are important for improving climate change prediction.
GLOBAL CHANGE BIOLOGY
(2023)
Article
Environmental Sciences
Tong Jiao, Christopher A. A. Williams, Martin G. G. De Kauwe, Belinda E. Medlyn
Summary: Drought-induced vegetation declines have global implications for ecosystem composition, structure, and functions. Understanding how vegetation responds to drought is critical, with factors such as timing, duration, and repeat exposure potentially influencing ecosystem response. Cumulative effects of repeated exposure to drought were found to have limited influence on drought impacts on canopy structure, affecting only a few areas.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Ecology
Brianna Lind, Tercia Strydom, Niall P. Hanan
Summary: There are many termite mounds in African savannas, and their interactions with vegetation and their potential role in redistributing water are of significant interest for ecosystem function and services. We assessed mound hydrological properties and explored the potential for termite mound-mediated water redistribution to affect vegetation growth in water-limited savanna systems. Our findings show that bare termite mounds have the potential to locally redistribute water during rainfall events, inhibiting vegetation colonization of the mound while potentially benefiting mound-adjacent vegetation.
JOURNAL OF ARID ENVIRONMENTS
(2023)
Article
Multidisciplinary Sciences
Luciana V. Gatti, Camilla L. Cunha, Luciano Marani, Henrique L. G. Cassol, Cassiano Gustavo Messias, Egidio Arai, A. Scott Denning, Luciana S. Soler, Claudio Almeida, Alberto Setzer, Lucas Gatti Domingues, Luana S. Basso, John B. Miller, Manuel Gloor, Caio S. C. Correia, Graciela Tejada, Raiane A. L. Neves, Raoni Rajao, Felipe Nunes, Britaldo S. S. Filho, Jair Schmitt, Carlos Nobre, Sergio M. Correa, Alber H. Sanches, Luiz E. O. C. Aragao, Liana Anderson, Celso Von Randow, Stephane P. Crispim, Francine M. Silva, Guilherme B. M. Machado
Summary: The carbon sink of the Amazon forest is declining due to land-use and climate change. The decrease in law enforcement has led to increased deforestation, biomass burning, and forest degradation, resulting in higher carbon emissions and exacerbation of drying and warming in the Amazon rainforest.
Review
Environmental Sciences
Sophie Ruehr, Trevor F. Keenan, Christopher Williams, Yu Zhou, Xinchen Lu, Ana Bastos, Josep G. Canadell, Iain Colin Prentice, Stephen Sitch, Cesar Terrer
Summary: This article investigates the storage and growth of carbon in the terrestrial biosphere, highlighting the importance of understanding the processes driving the carbon sink for mitigating climate change. The article suggests that continued carbon sequestration is possible through nature-based climate solutions and appropriate ecosystem management.
NATURE REVIEWS EARTH & ENVIRONMENT
(2023)
Article
Agricultural Engineering
S. Sai Kachout, S. Ben Youssef, S. Khnissi, K. Guenni, A. Zoghlami, A. Ennajah, N. Ghorbel, J. Anchang, N. P. Hanan
Summary: Perennial grasses are crucial for the sustainability of livestock pastures and can provide more effective ecosystem services in arid and semi-arid environments compared to annual crops. This study evaluated the impact of different defoliation frequencies on forage production and nutritive value of Phalaris aquatica L. in Tunisia. Results showed that moderate defoliation rates resulted in the highest dry matter production and regrowth rates. Secondary metabolite concentrations and antioxidant activity decreased with increased defoliation frequencies. The findings suggest that managing P. aquatica with moderate harvest rates is essential for perennial grass forage production systems in Tunisia.
JOURNAL OF THE ASABE
(2023)