Physical Sciences and Mathematics Commons^™

Roadway Floods And Their Associated Weather-Related Conditions: New Insights Using Cars 511 Data For State And Federal Highways In Nebraska, Usa, Logan R. Bundy, Mark Anderson, Clinton M. Rowe, Rezaul Mamood

Department of Earth and Atmospheric Sciences: Faculty Publications

This study examined roadway flooding event data provided by the Nebraska Department of Transportation via the Condition Acquisition Reporting System (CARS) 511 archive (2016–2021). With these data, a novel analysis was completed to further the understanding of where, when, and why (meteorologically) roadway flooding occurs on Nebraska state and federal highways. In the study period, 298 roadway floods occurred, with an annual median of 16 per year. There was a greater risk for roadway floods to transpire more frequently in eastern Nebraska, which was attributed to the spatial climatology of heavy rainfall and the higher density of roadways and rivers. …

Investigating The Occurrence Of Blizzard Events Over The Contiguous United States Using Observations And Climate Projections, Ahmani Browne, Liang Chen

Department of Earth and Atmospheric Sciences: Faculty Publications

Over previous decades, the United States has been plagued by severe winter storms or blizzards, which caused millions of dollars in damages. However, the historical trend of blizzard events and the possible impacts of future global climate change on blizzard occurrences remain unclear. In this study, we analyzed historical blizzard occurrences using the observed storm event database, which shows that the Northern Plains, such as North Dakota, South Dakota, and Minnesota, had the most blizzard activities over the past 25 years. No significant trend in blizzard occurrence is found in those regions. When considering blizzards as compound events of strong …

Analogue Model Of Rift Linkage And Inversion With Application To The Western Alps, Nicolas Dall’Asta, Yoann Denèle, Vincent Regard, Anne Frayssignes, Guilhem Hoareau, Sylvie Leroy, Thibaut Pires

Department of Earth and Atmospheric Sciences: Faculty Publications

Along-strike segmentation of orogens raises questions because its causes may predate orogeny in relation to structural inheritance. Here we focus on rift/margin linkage domains and their inversion by using analogue models with image analysis to extract the 3D strain field. Extensional models document, depending on the strike-perpendicular offset and the brittle-crust thickness, three types of rift linkage modes: (1) oblique linkage with early T-fault, (2) strongly-oblique linkage with R-fault network and, (3) transfer-linkage with late Y-strike-slip fault. Analogue model of inverted rift basins is used to analyse the misunderstood tectonic evolution of transition zones in the segmented Western Alpine belt.

Climate Change Impacts And Adaptation To Permafrost Change In High Mountain Asia: A Comprehensive Review, Prashant Baral, Simon Allen, Jakob F. Steiner, Tika R. Gurung, Graham Mcdowell

Department of Earth and Atmospheric Sciences: Faculty Publications

Changing climatic conditions in High Mountain Asia (HMA), especially regional warming and changing precipitation patterns, have led to notable effects on mountain permafrost. Comprehensive knowledge of mountain permafrost in HMA is mostly limited to the mountains of the Qinghai-Tibetan Plateau, with a strong cluster of research activity related to critical infrastructure providing a basis for related climate adaptation measures. Insights related to the extent and changing characteristics of permafrost in the Hindu Kush Himalaya (HKH), are much more limited. This study provides the first comprehensive review of peer-reviewed journal articles, focused on hydrological, ecological, and geomorphic impacts associated with thawing …

Elevated Risk Of Compound Extreme Precipitation Preceded By Extreme Heat Events In The Upper Midwestern United States, Manas Khan, Rabin Bhattarai, Liang Chen

Department of Earth and Atmospheric Sciences: Faculty Publications

Compound extreme events can potentially cause deadlier socio-economic consequences. Although several studies focused on individual extreme climate events, the occurrence of compound extreme events is still not well studied in the upper Midwestern United States. In this study, compound extreme precipitation preceded by extreme hot day events was investigated. Results showed a strong linkage between extreme precipitation events and extreme hot days. A significant increasing trend was noticed mainly in Iowa (10.1%), northern parts of Illinois (5.04%), and Michigan (5.04%). Results also showed a higher intensity of extreme precipitation events preceded by an extremely hot day compared to the intensity …

Shallow-Water Hydrothermal Venting Linked To The Palaeocene–Eocene Thermal Maximum, Christian Berndt, Sverre Planke, Carlos A. Alvarez Zarikian, Joost Frieling, Morgan T. Jones, John M. Millett, Henk Brinkhuis, Stefan Bünz, Henrik H. Svensen, Jack Longman, Reed P. Scherer, Jens Karstens, Ben Manton, Mei Nelissen, Brandon Reed, Jan Inge Faleide, Ritske S. Huismans, Amar Agarwal, Graham D.M. Andrews, Peter Betlem, Joyeeta Bhattacharya, Sayantani Chatterjee, Marialena Christopoulou, Vincent J. Clementi, Eric C. Ferré, Irina Filina, Pengyuan Guo, Dustin T. Harper, Sarah Lambart, Geoffroy Mohn, Reina Nakaoka, Christian Tegner, Natalia Varela, Mengyuan Wang

Department of Earth and Atmospheric Sciences: Faculty Publications

The Palaeocene–Eocene Thermal Maximum (PETM) was a global warming event of 5–6 °C around 56 million years ago caused by input of carbon into the ocean and atmosphere. Hydrothermal venting of greenhouse gases produced in contact aureoles surrounding magmatic intrusions in the North Atlantic Igneous Province have been proposed to play a key role in the PETM carbon-cycle perturbation, but the precise timing, magnitude and climatic impact of such venting remains uncertain. Here we present seismic data and the results of a five-borehole transect sampling the crater of a hydrothermal vent complex in the Northeast Atlantic. Stable carbon isotope stratigraphy …

Machine Learning Techniques To Predict The Air Quality Using Meteorological Data In Two Urban Areas In Sri Lanka, Lakindu Mampitiya, Namal Rathnayake, Lee P. Leon, Vishwanadham Mandala, Hazi Md. Azamathulla, Sherly Shelton, Yukinobu Hoshino, Upaka Rathnayake

Department of Earth and Atmospheric Sciences: Faculty Publications

The effect of bad air quality on human health is a well-known risk. Annual health costs have significantly been increased in many countries due to adverse air quality. Therefore, forecasting air quality-measuring parameters in highly impacted areas is essential to enhance the quality of life. Though this forecasting is usual in many countries, Sri Lanka is far behind the state-of-the-art. The country has increasingly reported adverse air quality levels with ongoing industrialization in urban areas. Therefore, this research study, for the first time, mainly focuses on forecasting the PM₁₀ values of the air quality for the two urbanized areas …

Cooler Forests In Clean Air, Liang Chen

Department of Earth and Atmospheric Sciences: Faculty Publications

Improving air quality by reducing atmospheric aerosols can bring valuable health benefits, but also generally leads to warming. Now, research suggests that in cleaner air the local cooling effect of planting trees may be stronger in middle and low latitude regions.

Forests provide a substantial sink for atmospheric carbon and therefore have great potential for contributing to climate change mitigation globally.¹ Meanwhile, forests play an important role in local and regional climate through their effects on albedo, evapotranspiration, and surface roughness.² The biogeophysical mechanisms driving forest-climate feedback depend strongly on the local background climate. But it remains unclear …

Corrigendum To “Testing Pyroxenite Versus Peridotite Sources For Marine Basalts Using U-Series Isotopes” [Lithos 332–333 (2019) 226–244], Lynne J. Elkins, Bernard Bourdon, Sarah Lambart

Department of Earth and Atmospheric Sciences: Faculty Publications

The authors regret that a small error in the dynamic melting Matlab script used for this paper produced erroneous results for some of the included modeling outcomes. We have written an updated modeling program in python, which can be accessed in the ENKI and pyUserCalc public data repository (https://gitlab.com/ENKI-portal/pyUsercalc/). Although the corrected results shown in revised versions of Figs. S3, S4, S8, S9, and S10 now appear quite different from the original publication, however, we find that when restricted to plausible scenarios of interest, our conclusions overall have not significantly changed. Some details of our results and discussion require corrections, …

Climate-Controlled Submarine Landslides On The Antarctic Continental Margin, Jenny A. Gales, Robert M. Mckay, Laura De Santis, Michele Rebesco, Jan Sverre Laberg, Amelia E. Shevenell, David M. Harwood, R. Mark Leckie, Denise K. Kulhanek, Maxine King, Molly Patterson, Renata G. Lucchi, Sookwan Kim, Sunghan Kim, Justin Dodd, Julia Seidenstein, Catherine Prunella, Giulia M. Ferrante, Iodp Expedition

Department of Earth and Atmospheric Sciences: Faculty Publications

Antarctica’s continental margins pose an unknown submarine landslidegenerated tsunami risk to Southern Hemisphere populations and infrastructure. Understanding the factors driving slope failure is essential to assessing future geohazards. Here, we present a multidisciplinary study of a major submarine landslide complex along the eastern Ross Sea continental slope (Antarctica) that identifies preconditioning factors and failure mechanisms. Weak layers, identified beneath three submarine landslides, consist of distinct packages of interbedded Miocene- to Pliocene-age diatom oozes and glaciomarine diamicts. The observed lithological differences, which arise from glacial to interglacial variations in biological productivity, ice proximity, and ocean circulation, caused changes in sediment deposition …

Permian Trilobites And The Applicability Of The “Living Fossil” Concept To Extinct Clades, Melanie J. Hopkins, Peter Wagner, Katherine J. Jordan

Department of Earth and Atmospheric Sciences: Faculty Publications

Some taxa occupy our imaginations as “living fossils” because they were known from the fossil record before being discovered alive today. Other taxa are considered “living fossils” because modern relatives bear a strong morphological resemblance to fossil relatives, or because they occupy a contracted geographic range or have less diversity now than in the past, or because they represent phylogenetic diversity that requires conservation. A characterizing feature of living fossils–and thus an implicit assumption of all criteria–is that the “living fossil” of interest is extant. However, the general research questions that “living fossils” inspire–Why do rates of evolution vary across …

The Earliest Dipodomyine Heteromyid In North America And The Phylogenetic Relationships Of Geomorph Rodents, Joshua X. Samuels, Jonathan J.-M. Calede, Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

Dipodomyine heteromyids (kangaroo rats and mice) are a diverse group of aridadapted ricochetal rodents of North America. Here, a new genus and species of a large dipodomyine is reported from early Miocene-aged deposits of the John Day Formation in Oregon that represents the earliest record of the subfamily. The taxon is known from a single specimen consisting of a nearly complete skull, dentary, partial pes, and caudal vertebra. The specimen is characterized by a mosaic of ancestral and highly derived cranial features of heteromyids. Specifically, the dental morphology and some cranial characteristics are similar to early heteromyids, but other aspects …

Global Three-Dimensional Water Vapor Feature-Tracking For Horizontal Winds Using Hyperspectral Infrared Sounder Data From Overlapped Tracks Of Two Satellites, Amir Ouyed, Nadia Smith, Xubin Zeng, Thomas Galarneau Jr., Hui Su, Ross D. Dixon

Department of Earth and Atmospheric Sciences: Faculty Publications

The lack of measurements of three-dimensional (3D) distribution of horizontal wind vectors is a major challenge in atmospheric science. Here, we develop an algorithm to retrieve winds for nine pressure levels at 1° grid spacing from 70°N to 70°S. The retrieval is done by tracking water vapor from the hyperspectral Cross-track Infrared Sounder aboard two polar satellites (NOAA-20 and Suomi-NPP) that have overlapped tracks separated by 50 min. We impose a gross error check by flagging retrievals that are too different from ERA-5 reanalysis. Testing the algorithm for the first week of January and July 2020 indicates that our algorithm …

Exhumed Fluvial Landforms Reveal Evolution Of Late Eocene– Pliocene Rivers On The Central And Northern Great Plains, Usa, Jesse T. Korus, Robert Matthew Joeckel

Department of Earth and Atmospheric Sciences: Faculty Publications

Cenozoic strata on the Great Plains are the products of a long- lived, continental sediment routing system, and yet strikingly little is known about these ancient rivers. This article details the discovery of ~3100 fluvial ridges—erosionally inverted alluvial- fan, channel- fill, channel- belt, and valley- fill deposits—extending from the Rocky Mountain front to the eastern margin of the Great Plains. The direct detection of these channel bodies reveals new insights into late Eocene– Pliocene drainage evolution. Late Eocene– Oligocene streams were morphologically diverse. Alluvial fans adjacent to the Rocky Mountain front changed eastward to parallel or downstream- divergent, fixed, single- …

Near-Cloud Atmospheric Ingredients For Deep Convection Initiation, James N. Marquis, Zhe Feng, Adam Varble, T. Connor Nelson, Adam L. Houston, John M. Peters, Jake P. Mulholland, Joseph Hardi

Department of Earth and Atmospheric Sciences: Faculty Publications

A lack of routine environmental observations located near deepening cumulus congestus clouds limits verification of important theorized and simulated updraft–environment interaction processes occurring during deep convection initiation (CI). We analyze radiosonde profiles collected during several hundred CI events near a mountain range in central Argentina during the CACTI field campaign. Statistical analyses illustrate environmental conditions supporting radar-observed CI outcomes that span a spectrum of convective cell depths, widths, and durations, as well as events lacking precipitating convection. Tested environmental factors include a large variety of sounding-derived measurements of CAPE, CIN, moisture, terrain-relative winds, vertical shear, and lifted parcel properties, with …

Changes Of Air Pollutants In Urban Cities During The Covid-19 Lockdown-Sri Lanka, Buddhi Pushpawela, Sherly Shelton, Gayathri Liyanage, Sanduni Jayasekara, Dimuthu Rajapaksha, Akila Jayasundara, Lesty Das Jayasuriya

Department of Earth and Atmospheric Sciences: Faculty Publications

In response to the COVID-19 pandemic in early 2020, Sri Lanka underwent a nationwide lockdown that limited motor vehicle movement, industrial operations, and human activities. This study analyzes the impact of COVID-19 lockdown on carbon monoxide (CO), ozone (O₃), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and particulate matter (PM₁₀, PM_2.5) concentrations in two urban cities (Colombo and Kandy) in Sri Lanka, by comparison of data from the lockdown period (March to May 2020) with its analogous period of 2019 and 2021. The results showed that the percentage change of daytime …

Nitrate-Stimulated Release Of Naturally Occurring Sedimentary Uranium, Jeffrey Westrop, Pooja Yadav, Pj Nolan, Kate M. Campbell, Rajesh Singh, Sharon E. Bone, Alicia H. Chan, Anthony Kohtz, Donald Pan, Olivia Healy, John R. Bargar, Daniel D. Snow, Karrie A. Weber

Department of Earth and Atmospheric Sciences: Faculty Publications

Groundwater uranium (U) concentrations have been measured above the U.S. EPA maximum contaminant level (30 μg/L) in many U.S. aquifers, including in areas not associated with anthropogenic contamination by milling or mining. In addition to carbonate, nitrate has been correlated to uranium groundwater concentrations in two major U.S. aquifers. However, to date, direct evidence that nitrate mobilizes naturally occurring U from aquifer sediments has not been presented. Here, we demonstrate that the influx of high-nitrate porewater through High Plains alluvial aquifer silt sediments bearing naturally occurring U(IV) can stimulate a nitrate-reducing microbial community capable of catalyzing the oxidation and mobilization …

Holocene Variations In Lake Titicaca Water Level And Their Implications For Sociopolitical Developments In The Central Andes, Stéphane Guédron, Christophe Delaere, Sherilyn C. Fritz, Julie Tolu, Pierre Sabatier, Anne-Lise Devel, Carlos Heredia, Claire Vérin, Eduardo Q. Alves, Paul A. Baker

Department of Earth and Atmospheric Sciences: Faculty Publications

Holocene climate in the high tropical Andes was characterized by both gradual and abrupt changes, which disrupted the hydrological cycle and impacted landscapes and societies. High-resolution paleoenvironmental records are essential to contextualize archaeological data and to evaluate the sociopolitical response of ancient societies to environmental variability. Middle-to-Late Holocene water levels in Lake Titicaca were reevaluated through a transfer function model based on measurements of organic carbon stable isotopes, combined with high-resolution profiles of other geochemical variables and paleoshoreline indicators. Our reconstruction indicates that following a prolonged low stand during the Middle Holocene (4000 to 2400 BCE), lake level rose rapidly …

A Method For Successful Collection Of Multicores And Gravity Cores From Antarctic Subglacial Lakes, Brad E. Rosenheim, Alexander B. Michaud, James Broda, Alan Gagnon, Ryan A. Venturelli, Timothy D. Campbell, Amy Leventer, Molly Patterson, Matthew J. Siegfried, Brent C. Christner, Dennis Duling, David M. Harwood, John E. Dore, Martyn Tranter, Mark L. Skidmore, John C. Priscu, Salsa Science Team

Department of Earth and Atmospheric Sciences: Faculty Publications

During the 2018–2019 Antarctic field season, the Subglacial Antarctic Lakes Scientific Access project team cleanly accessed Mercer Subglacial Lake, West Antarctica, to sample water and sediments beneath 1087 m of overlying ice. A multicorer was successful in sampling the sediment–water interface, with 4 deployments retrieving 10 cores between 0.3 and 0.4 m in length. Gravity coring was also successful, retrieving cores of 0.97 and 1.78 m in glacial diamict. However, sediment cores retrieved by the gravity cores were shorter than the core barrel penetration (as measured by mud streaks on the outside of the coring system), indicating that the system …

Reply To The Discussion And Comments Of Azerêdo Et Al. (2023) And Schneider Et Al. (2023) On The Paper By Magalhães Et Al. ‘Middle Jurassic Multi-Scale Transgressive–Regressive Cycles: An Example From The Lusitanian Basin’, The Depositional Record, 9, 174–202, Antonio J.C. Magalhães, Gerson J.S. Terra, Felipe Guadagnin, Daniel G.C. Fragoso, Mirian C. Menegazzo, Nuno L.A. Pimentel, Sissa Kumaira, Gerson Fauth, Alessandra Santos, David K. Watkins, Mauro D.R. Bruno, Daiane Ceolin, Simone Baecker-Fauth, Guilherme P.R. Gabaglia, Washington L.E. Teixeira, Francisco P. Lima-Filho

Department of Earth and Atmospheric Sciences: Faculty Publications

cently published paper. The exchange of ideas, data and interpretation improves our knowledge and is the right way to discuss science's advances. This reply considers the points raised by Azerêdo et al. (2023) and Schneider et al. (2023). In both manuscripts, these authors raised many issues about sedimentological and stratigraphic aspects that can be separated into two groups: (a) those related to the age of the studied succession; and (b) those assigning the studied succession to the Candeeiros Formation.

A 1.8 Million Year History Of Amazon Vegetation, Andrea K. Kern, Thomas Kenji Akabane, Jaqueline Q. Ferreira, Cristiano M. Chiessi, Debra A. Willard, Fabricio Ferreira, Allan Oliveira Sanders, Cleverson G. Silva, Catherine Rigsby, Francisco W. Cruz, Gary S. Dwyer, Sherilyn C. Fritz, Paul A. Baker

Department of Earth and Atmospheric Sciences: Faculty Publications

During the Pleistocene, long-term trends in global climate were controlled by orbital cycles leading to high amplitude glacial-interglacial variability. The history of Amazonian vegetation during this period is largely unknown since no continuous record from the lowland basin extends significantly beyond the last glacial stage. Here we present a paleoenvironmental record spanning the last 1800 kyr based on palynological data, biome reconstructions, and biodiversity metrics from a marine sediment core that preserves a continuous archive of sediments from the Amazon River.

Tropical rainforests dominated the Amazonian lowlands during the last 1800 ka interchanging with surrounding warm-temperate rainforests and tropical seasonal …

Observations On Late Cretaceous Micrampulla (Corethrales, Bacillariophyceae) From The Campbell Plateau (Zealandia), Southwest Pacific Ocean, Kenta Abe, David M. Harwood, Richard W. Jordan

Department of Earth and Atmospheric Sciences: Faculty Publications

Late Cretaceous (late Campanian) diatom assemblages from the Campbell Plateau (Zealandia), southwest Pacific Ocean, obtained from Deep Sea Drilling Project (DSDP) Leg 29 Site 275, contain well-preserved specimens of two enigmatic diatom species currently assigned to the genus Ktenodiscus; Micrampulla parvula originally described from the Maastrichtian-age Moreno Shale, California, and Pterotheca cretacea from DSDP Site 275. In general, the two species share a number of common features with modern Corethron (domed valves, probable heterovalvate frustules, T-shaped serrated articulated spines, marginal sockets), but differ in the location of the sockets (i.e. vertically at the base of the valve dome and …

Biotic And Paleoceanographic Changes Across The Late Cretaceous Oceanic Anoxic Event 2 In The Southern High Latitudes (Iodp Sites U1513 And U1516, Se Indian Ocean), Maria Rose Petrizzo, Giulia Amaglio, David K. Watkins, Kenneth G. Macleod, Brian T. Huber, Takashi Hasegawa, Erik Wolfgring

Department of Earth and Atmospheric Sciences: Faculty Publications

Oceanic Anoxic Event 2, spanning the Cenomanian/Turonian boundary (93.9 Ma), was an episode of major perturbations in the global carbon cycle. To investigate the response of biota and the paleoceanographic conditions across this event, we present data from International Ocean Discovery Program sites U1513 and U1516 in the Mentelle Basin (offshore SW Australia; paleolatitude 59°–60°S in the mid-Cretaceous) that register the first complete records of OAE 2 at southern high latitudes. Calcareous nannofossils provide a reliable bio-chronostratigraphic framework. The distribution and abundance patterns of planktonic and benthic foraminifera, radiolaria, and calcispheres permit interpretation of the dynamics of the water mass …

Vortex Sheet Sensitivity To Low-Level Vertical Shear And Airmass Temperature Perturbation, Adam L. Houston, George L. Limpert

Department of Earth and Atmospheric Sciences: Faculty Publications

A theoretical, numerical-modeling-based examination of the sensitivity of vortex sheets along airmass boundaries to the following three characteristics is presented: 1) boundary-normal component of the vertical wind shear, 2) boundary-parallel component of the vertical wind shear, and 3) temperature perturbation within the parent air mass of the boundary. The overall aim of this work is to advance understanding of the sensitivity of micro-α- tomeso-γ-scale vortex generation along airmass boundaries to the ambient environment. Density currents are simulated in a 2D domain that does not allow baroclinic generation of near-surface vertical vorticity (ζ_ns) with parameterized latent heating for convection …

The Dynamic Floor Of Yellowstone Lake, Wyoming, Usa: The Last 14 K.Y. Of Hydrothermal Explosions, Venting, Doming, And Faulting, L. A. Morgan, W. C.P. Shanks, K. L. Pierce, N. Iverson, C. M. Schiller, S. R. Brown, P. Zahajska, R. Cartier, R. W. Cash, J. L. Best, C. Whitlock, Sherilyn C. Fritz, U.S. Geological Survey, H. Lowers, D. A. Lovalvo, J. M. Licciardi

Department of Earth and Atmospheric Sciences: Faculty Publications

Hydrothermal explosions are significant potential hazards in Yellowstone National Park, Wyoming, USA. The northern Yellowstone Lake area hosts the three largest hydrothermal explosion craters known on Earth empowered by the highest heat flow values in Yellowstone and active seismicity and deformation. Geological and geochemical studies of eighteen sublacustrine cores provide the first detailed synthesis of the age, sedimentary facies, and origin of multiple hydrothermal explosion deposits.New tephrochronology and radiocarbon results provide a four-dimensional view of recent geologic activity since recession at ca. 15–14.5 ka of the >1-km-thick Pinedale ice sheet.

The sedimentary record in Yellowstone Lake contains multiple hydrothermal explosion …

Terrestrial Carbon Isotope Stratigraphy And Mammal Turnover During Post-Petm Hyperthermals In The Bighorn Basin, Wyoming, Usa, Sarah J. Widlansky, Ross Secord, Kathryn E. Snell, Amy E. Chew, William C. Clyde

Department of Earth and Atmospheric Sciences: Faculty Publications

Paleogene hyperthermals, including the Paleocene–Eocene Thermal Maximum (PETM) and several other smaller events, represent global perturbations to Earth’s climate system and are characterized by warmer temperatures, changes in floral and faunal communities, and hydrologic changes. These events are identified in the geologic record globally by negative carbon isotope excursions (CIEs), resulting from the input of isotopically light carbon into Earth’s atmosphere. Much about the causes and effects of hyperthermals remains uncertain, including whether all hyperthermals were caused by the same underlying processes, how biotic effects scale with the magnitude of hyperthermals, and why CIEs are larger in paleosol carbonates relative …

Seasonally And Diurnally Varying Cold Front Effects Along The Minnesotan North Shore Of Lake Superior, Matthew S. Van Den Broeke

Department of Earth and Atmospheric Sciences: Faculty Publications

Cold fronts are typically associated with cooling, drying and a strengthening wind that shifts to have a northerly component. Cold front effects at a particular point, however, are dependent upon pre-existing air mass characteristics. Here, we examine 634 passages of synoptic-scale cold fronts in northeastern Minnesota from 2010 to 2018. While these fronts are associated with the expected effects in some areas, they are often associated with warming and enhanced drying in the region directly influenced by an air mass from Lake Superior (coastal sites). Coastal sites experience warming during more than half of cold frontal passages, in contrast to …

Analysis Of Groundwater Recharge In Mongolian Drylands Using Composite Vadose Zone Modeling, Khulan Batsukh, Vitaly A. Zlotnik, Paolo Nasta

Department of Earth and Atmospheric Sciences: Faculty Publications

Knowledge of groundwater recharge (GR) is important for the effective management of water resources under semi-arid continental climates. Unfortunately, studies and data in Mongolia are limited due to the constraints in funding and lack of research infrastructures. Currently, the wide accessibility of freely available global-scale digital datasets of physical and chemical soil properties, weather data, vegetation characteristics, and depths to the water table offers new tools and basic information that can support low-cost physically based and process-oriented models. Estimates of GR over 41 study sites in Mongolia were obtained using HYDRUS-1D in a 2-m-thick soil profile with root …

Cloud Radiative Effects On Mjo Development In Dynamo, Qi Hu, Zihang Han, Shuguang Wang

Department of Earth and Atmospheric Sciences: Faculty Publications

Observed Madden–Julian oscillation (MJO) events are examined with the aid of regional model simulations to understand the role of cloud radiative effects in the MJO development. The importance of this role is demonstrated by the absence of the MJO in the model simulations that contain no cloud radiative effects. Comparisons of model simulations with and without the cloud radiative effects and observation help identify the major processes arising from those effects. Those processes develop essentially from heating in the upper troposphere due to shortwave absorption within anvil clouds in the upper troposphere and the convergence of longwave radiation in the …

Recent Advances Toward Transparent Methane Emissions Monitoring: A Review, Broghan M. Erland, Andrew K. Thorpe, John Gamon

Department of Earth and Atmospheric Sciences: Faculty Publications

Given that anthropogenic greenhouse gas (GHG) emissions must be immediately reduced to avoid drastic increases in global temperature, methane emissions have been placed center stage in the fight against climate change. Methane has a significantly larger warming potential than carbon dioxide. A large percentage of methane emissions are in the form of industry emissions, some of which can now be readily identified and mitigated. This review considers recent advances in methane detection that allow accurate and transparent monitoring, which are needed for reducing uncertainty in source attribution and evaluating progress in emissions reductions. A particular focus is on complementary methods …