scholarly journals The Simulated Impact of the Snow Albedo Feedback on the Large-Scale Mountain–Plain Circulation East of the Colorado Rocky Mountains

2018 ◽  
Vol 75 (3) ◽  
pp. 755-774 ◽  
Author(s):  
Theodore W. Letcher ◽  
Justin R. Minder
Keyword(s):  
Interannual Variability ◽  
Great Plains ◽  
Rocky Mountains ◽  
Large Scale ◽  
The United States ◽  
Front Range ◽  
Albedo Feedback ◽  
Snow Albedo ◽  
Colorado Rocky Mountains

Abstract The Front Range mountain–plain circulation (FRMC) is a large-scale diurnally driven wind system that occurs east of the Colorado Rocky Mountains in the United States and affects the weather both in the Rocky Mountains and Great Plains. As the climate warms, the snow albedo feedback will amplify the warming response in the Rocky Mountains during the spring, increasing the thermal contrast that drives the FRMC. In this study, the authors perform a 7-yr pseudo–global warming (PGW) regional climate change experiment along with an idealized PGW “fixed albedo” experiment to test the sensitivity of the FRMC to the snow albedo feedback (SAF). The authors find a mean increase in the springtime FRMC strength in the PGW experiment that is primarily driven by the snow albedo feedback. Furthermore, interannual variability of changes in FRMC strength is strongly influenced by interannual variability in the SAF. An additional case study experiment configured with a much higher resolution is performed to examine the finescale details of how the SAF and the FRMC interact. This experiment includes a passive tracer to investigate subsequent impacts on pollution transport. The case study reveals that loss of snow cover causes an increase in the strength of the FRMC. Advection by the strengthened FRMC increases the concentration of tracers emitted over the Great Plains in the boundary layer over the Front Range mountains.

scholarly journals Climatology of Severe Local Storm Environments and Synoptic-Scale Features over North America in ERA5 Reanalysis and CAM6 Simulation

2020 ◽  
Vol 33 (19) ◽  
pp. 8339-8365 ◽  
Author(s):  
Funing Li ◽  
Daniel R. Chavas ◽  
Kevin A. Reed ◽  
Daniel T. Dawson II
Keyword(s):  
United States ◽  
North America ◽  
Great Plains ◽  
Large Scale ◽  
Extreme Values ◽  
Convective Available Potential Energy ◽  
The United States ◽  
Synoptic Scale ◽  
Low Level ◽  
High Bias

AbstractSevere local storm (SLS) activity is known to occur within specific thermodynamic and kinematic environments. These environments are commonly associated with key synoptic-scale features—including southerly Great Plains low-level jets, drylines, elevated mixed layers, and extratropical cyclones—that link the large-scale climate to SLS environments. This work analyzes spatiotemporal distributions of both extreme values of SLS environmental parameters and synoptic-scale features in the ERA5 reanalysis and in the Community Atmosphere Model, version 6 (CAM6), historical simulation during 1980–2014 over North America. Compared to radiosondes, ERA5 successfully reproduces SLS environments, with strong spatiotemporal correlations and low biases, especially over the Great Plains. Both ERA5 and CAM6 reproduce the climatology of SLS environments over the central United States as well as its strong seasonal and diurnal cycles. ERA5 and CAM6 also reproduce the climatological occurrence of the synoptic-scale features, with the distribution pattern similar to that of SLS environments. Compared to ERA5, CAM6 exhibits a high bias in convective available potential energy over the eastern United States primarily due to a high bias in surface moisture and, to a lesser extent, storm-relative helicity due to enhanced low-level winds. Composite analysis indicates consistent synoptic anomaly patterns favorable for significant SLS environments over much of the eastern half of the United States in both ERA5 and CAM6, though the pattern differs for the southeastern United States. Overall, our results indicate that both ERA5 and CAM6 are capable of reproducing SLS environments as well as the synoptic-scale features and transient events that generate them.

CCS AS ONE OF the CO2 EMISSION REDUCTION METHODS

2017 ◽  
pp. 1-8
Author(s):  
Teresa ADAMCZAK-BIAŁY ◽  
Adam WÓJCICKI
Keyword(s):  
United States ◽  
Great Plains ◽  
Oil Recovery ◽  
Carbon Capture ◽  
Large Scale ◽  
Carbon Capture And Storage ◽  
The United States ◽  
Geological Storage ◽  
Co2 Emission Reduction ◽  
And Storage

Information presented in the article allows us to introduce one of the ways of reducing anthropogenic greenhouse gas emissions responsible for the temperature increase and climate change. This is the technology of capture and underground storage of carbon dioxide in geologic structures (Carbon Capture and Storage/Sequestration – CCS). Most of the large-scale CCS projects (i.e. capture and storage of an order of magnitude of 1 million tonnes of CO2 per year) operate in the United States and Canada. Many of them are associated with the use of CO2 captured from the industrial processes for the enhanced oil recovery (EOR). The presented examples of projects are: Boundary Dam Integrated Carbon Capture and Sequestration Demonstration Project (Canada), Great Plains Synfuels and Weyburn-Midale Project (Canada), and Kemper County IGCC Project (United States). CCS projects are crucial for demonstrating the technological readiness and reduce the cost of wider commercial implementation of capture and geological storage of CO2. The status of the projects on geological storage of CO2 in 2015 is 15 large-scale CCS projects operating around the world, and 7 projects in execution.

The impacts of ENSO and PNA teleconnections on upper-level coupling to the Great Plains low-level jet

2020 ◽  
Author(s):  
D. Alex Burrows ◽  
Craig Ferguson ◽  
Shubhi Agrawal ◽  
Lance Bosart
Keyword(s):  
Great Plains ◽  
Large Scale ◽  
The United States ◽  
Jet Stream ◽  
Central Pacific ◽  
Frequency Distributions ◽  
Low Level ◽  
Enso Events ◽  
Low Level Jet ◽  
Upper Level

<p>The United States (U.S.) Great Plains southerly low-level jet (GPLLJ) is a ubiquitous feature of the summertime climatological flow in the central U.S. contributing to a large percentage of mean and extreme summertime rainfall, the generation of vast quantities of U.S. renewable wind energy, and severe weather outbreaks.  Like other LLJs across the globe, the GPLLJ can be 1) vertically coupled to the large-scale cyclone-anticyclone flow pattern associated with an upper-level jet stream or 2) uncoupled to the large-scale flow but sustained in response to various local land-atmosphere coupling mechanisms.  Many studies have focused on the interactions between teleconnection patterns and associated GPLLJ variability, treating the GPLLJ as a singular phenomenon.  Here, we treat the GPLLJ as two phenomena, coupled and uncoupled to the upper-level flow, and explore the multiscale impacts of SST forced and internally generated modes of variability on the GPLLJ.  With mounting evidence for the low-frequency control on higher frequency GPLLJ variability, the current study analyzes the contribution of the Pacific/North America (PNA) pattern on sub-seasonal timescales and ENSO on interannual timescales to changes in the frequency distributions of both coupled and uncoupled GPLLJs.</p><p> </p><p>This analysis utilizes 1) the Coupled ERA 20th Century (CERA-20C; 1901-2010) reanalysis from ECMWF which provides a large sample of teleconnection conditions and their impacts on GPLLJ variability and 2) a recently developed automated technique to differentiate those GPLLJs that are coupled or uncoupled to the upper-level flow.  Many studies have already shown that two distinct synoptic regimes dominate GPLLJ variability, a western U.S. trough and a central U.S. ridge.  This leads to changes in the frequency ratio of coupled and uncoupled GPLLJ events and ultimately in the location and intensity of precipitation across the GP.  Recently, Burrows et al. (2019) showed that during the Dust Bowl period of 1932-1938, the central and northern GP experienced anomalously high (low) uncoupled (coupled) GPLLJ event frequencies that coincided with a multi-year dry period across the entire region.  Understanding the upscale and lower frequency forcing patterns that lead to these distinct synoptic regimes would lead to greater predictability and forecasting skill.  On sub-seasonal timescales, it is shown that the negative phase of the PNA, which is associated with a southerly displaced Pacific jet stream and a western U.S. trough, leads to increases in the frequency of GPLLJs that are coupled to the upper-level flow, increases in Gulf of Mexico moisture flux and a redistribution of GP precipitation.  On interannual timescales, the location of ENSO events, i.e., eastern or central Pacific, is explored to determine the relationship between tropical forced variability and upper-level coupling to the GPLLJ.  In line with recent studies, it is hypothesized that central Pacific ENSO events may lead to increases in coupled GPLLJ events and precipitation, particularly in the southern GP.</p>

scholarly journals Mesoscale Moisture Transport by the Low-Level Jet during the IHOP Field Experiment

2008 ◽  
Vol 136 (10) ◽  
pp. 3781-3795 ◽  
Author(s):  
Edward I. Tollerud ◽  
Fernando Caracena ◽  
Steven E. Koch ◽  
Brian D. Jamison ◽  
R. Michael Hardesty ◽  
...  
Keyword(s):  
Great Plains ◽  
Cross Sections ◽  
Moisture Transport ◽  
Large Scale ◽  
Wrf Model ◽  
The United States ◽  
Small Scale ◽  
Low Level ◽  
Convective Scale ◽  
Low Level Jet

Previous studies of the low-level jet (LLJ) over the central Great Plains of the United States have been unable to determine the role that mesoscale and smaller circulations play in the transport of moisture. To address this issue, two aircraft missions during the International H2O Project (IHOP_2002) were designed to observe closely a well-developed LLJ over the Great Plains (primarily Oklahoma and Kansas) with multiple observation platforms. In addition to standard operational platforms (most important, radiosondes and profilers) to provide the large-scale setting, dropsondes released from the aircraft at 55-km intervals and a pair of onboard lidar instruments—High Resolution Doppler Lidar (HRDL) for wind and differential absorption lidar (DIAL) for moisture—observed the moisture transport in the LLJ at greater resolution. Using these observations, the authors describe the multiscalar structure of the LLJ and then focus attention on the bulk properties and effects of scales of motion by computing moisture fluxes through cross sections that bracket the LLJ. From these computations, the Reynolds averages within the cross sections can be computed. This allow an estimate to be made of the bulk effect of integrated estimates of the contribution of small-scale (mesoscale to convective scale) circulations to the overall transport. The performance of the Weather Research and Forecasting (WRF) Model in forecasting the intensity and evolution of the LLJ for this case is briefly examined.

scholarly journals Coupling between Large-Scale Atmospheric Processes and Mesoscale Land–Atmosphere Interactions in the U.S. Southern Great Plains during Summer. Part I: Case Studies

2004 ◽  
Vol 5 (6) ◽  
pp. 1223-1246 ◽  
Author(s):  
Christopher P. Weaver
Keyword(s):  
Great Plains ◽  
Large Scale ◽  
Deep Convection ◽  
Individual Case ◽  
Atmospheric Modeling ◽  
Surface Fluxes ◽  
Southern Great Plains ◽  
Atmospheric Processes ◽  
Mesoscale Processes

Abstract This paper is Part I of a two-part study that uses high-resolution Regional Atmospheric Modeling System (RAMS) simulations to investigate mesoscale land–atmosphere interactions in the summertime U.S. Southern Great Plains. The focus is on the atmospheric dynamics associated with mesoscale heterogeneity in the underlying surface fluxes: how shifts in meteorological regimes modulate these diurnal, mesoscale processes, and their overall impact at larger scales and over multiple diurnal cycles. Part I examines individual case study time periods drawn from the simulations that illustrate general points about the key land–atmosphere interactions. The main findings are as follows: The mesoscale processes are embedded within a synoptic-scale organization that controls the background meteorological regime at a given location. During the clear, dry days in the simulated months, heterogeneity in the surface fluxes forces strong, lower-tropospheric, mesoscale circulations that exhibit a characteristic dynamical life cycle over diurnal time scales. In general, the background large-scale flow does not affect the overall intensity of these coherent roll structures, though strong large-scale subsidence can sometimes dampen them. In addition, depending on the thermodynamic profile, the strong vertical motions associated with these circulations are sufficient to trigger shallow or even deep convection, with associated clouds and precipitation. Furthermore, surface heterogeneity sufficient to force such circulations can arise even without heterogeneity in preexisting land cover characteristics such as vegetation, for example, solely as a result of spatial variability in rainfall and other atmospheric processes. In Part II the mesoscale land–atmosphere interactions in these case study periods are placed in the larger context of the full, monthlong simulations.

The Diurnal and Seasonal Variation of the Northern Australian Dryline

2007 ◽  
Vol 135 (8) ◽  
pp. 2995-3008 ◽  
Author(s):  
Sarah J. Arnup ◽  
Michael J. Reeder
Keyword(s):  
Great Plains ◽  
Sea Breeze ◽  
The United States ◽  
Moisture Gradient ◽  
Limited Area ◽  
Mixing Ratio ◽  
Prediction Scheme ◽  
Thermodynamic Variables ◽  
Good Agreement

Abstract The diurnal and seasonal variations of the northern Australian dryline are examined by constructing climatologies of low-level dynamic and thermodynamic variables taken from the high-resolution Australian Bureau of Meteorology’s Limited Area Prediction Scheme (LAPS) forecasts from 2000 to 2003. The development of the dryline is analyzed within the framework of the frontogenesis function applied to the mixing ratio and the airstream diagnostics of Cohen and Schultz. A case study of 12–13 October 2002 illustrating the airmass boundaries over the Australian region is also examined. Daytime surface heating produces sea-breeze circulations around the coast and a large inland heat trough that extends east–west along northern Australia. At night, air parcels accelerate toward low pressure, increasing convergence and deformation within the heat trough. This sharpens the moisture gradient across the tropical and continental airmass boundary into a dryline. This is different than the dryline of the Great Plains in the United States, which generally weakens overnight. The Australian dryline is strongest in spring just poleward of the Gulf of Carpentaria, where the moisture gradient across the heat trough is enhanced by the coast, and the axis of dilatation is closely aligned with mixing ratio isopleths. The dryline is weakest in winter, when the heat trough is weak. The LAPS 3-h forecasts are in good agreement with observations obtained from the Automatic Weather Station network. The 3-h forecasts capture the observed diurnal and seasonal cycle of the airmass boundaries. However, the sea-breeze circulation and ageostrophic flow into the surface heat trough is limited by the model resolution. The LAPS 3-h forecasts may therefore underestimate the nocturnal intensification of the dryline, especially since the inland moisture content is overestimated.

scholarly journals Blackberry Propagation Limitations When Using Floricane Cuttings

2019 ◽  
Vol 29 (3) ◽  
pp. 276-282 ◽  
Author(s):  
Abigail R. Debner ◽  
Harlene Hatterman-Valenti ◽  
Fumiomi Takeda
Keyword(s):  
United States ◽  
Great Plains ◽  
Production System ◽  
Adventitious Root ◽  
Large Scale ◽  
Root Formation ◽  
The United States ◽  
Annual Production ◽  
Root Production ◽  
Northern Great Plains

Outdoor production of floricane-fruiting (FF) blackberry (Rubus subgenus Rubus) is problematic in the Northern Great Plains region of the United States because cane injury and plant death will occur from exposure to temperatures −15 °C and colder. An annual FF blackberry production system using hardwood floricane cuttings would overcome some of the existing limitations of traditional production methods. Several experiments were performed to induce adventitious root formation from one-node hardwood floricane blackberry cuttings taken in winter for the purpose of subsequent growth of a floral shoot. One-node hardwood cuttings of multiple blackberry cultivars (Apache, Arapaho, Kiowa, Osage, Ouachita, Siskiyou, and Triple Crown) were evaluated for rooting potential with and without auxin treatments. Root formation was virtually nonexistent for ‘Apache’, ‘Kiowa’, and ‘Triple Crown’ regardless of the auxin treatment. In general, lower auxin concentrations and the powder formulation produced more roots and had higher root ratings. However, rooting success of cuttings and plant development was low regardless of the rooting method used. Adventitious root production of one-node dormant hardwood FF blackberry cuttings for use in an annual production system had low success regardless of the cultivar, auxin application, rate, and formulation. The variable propagation success rates using single-node hardwood cuttings from ‘Apache’, ‘Arapaho’, ‘Kiowa’, ‘Osage’, ‘Ouachita’, ‘Siskiyou’, and ‘Triple Crown’ plants grown in containers in North Dakota suggested insufficient rooting success for the recommendation of this practice. Additionally, the results suggested these cultivars are not suitable using this method for an annual production system or as a means for large-scale propagation. Although this approach to developing plants from cuttings is of great interest, without a more effective FF blackberry cutting rooting method that can progress through fruit production, an annual blackberry production system in the Northern Great Plains region of the United States is unlikely.

scholarly journals Engaging Adults Experiencing Homelessness in Smoking Cessation Through Large-Scale Community Service Events

2019 ◽  
Vol 20 (3) ◽  
pp. 325-327 ◽  
Author(s):  
Maya Vijayaraghavan ◽  
Dorie E. Apollonio
Keyword(s):  
Smoking Cessation ◽  
San Francisco ◽  
Community Service ◽  
Large Scale ◽  
The United States ◽  
Service Delivery Model ◽  
Smoking Cessation Counseling ◽  
Health Related

Cigarette smoking contributes substantially to the increased financial- and health-related burdens among adults experiencing homelessness. We describe findings from a case study of a model to increase access to cessation services among adults experiencing homelessness. In partnership with Project Homeless Connect (PHC), we piloted a unique service delivery model that involved providing brief cessation counseling and pharmacotherapy to smokers from this population attending large-scale service events in San Francisco, with the goal of connecting them to long-term smoking cessation care. We participated in three service events between October 2017 and March 2018. We offered brief smoking cessation counseling to 45 individuals, and smoking cessation counseling and pharmacotherapy to 7 individuals experiencing homelessness. This model could improve public health if expanded to other cities, particularly the 200 other cities in the United States offering PHC service events.

The adoptability of perennial-based farming systems for hydrologic and salinity control in dryland farming systems in Australia and the United States of America

2009 ◽  
Vol 60 (1) ◽  
pp. 83 ◽  
Author(s):  
Anna M. Roberts ◽  
Matthew J. Helmers ◽  
Ian R. P. Fillery
Keyword(s):  
United States ◽  
Great Plains ◽  
United States Of America ◽  
Large Scale ◽  
Farming Systems ◽  
The United States ◽  
Development Programs ◽  
Learning Program ◽  
Dryland Salinity ◽  
The Usa

Dryland salinity and water quality problems occur in the Great Plains and cornbelt regions of the United States of America (USA) and southern Australia due to the replacement of native perennial systems by annual species. We outline the hydrological effects of selected farming systems in both countries and review progress towards development of new perennial systems with potential to reduce dryland salinity effects. In Australia, development and large-scale trialling are further advanced than in the USA. In both countries there are usually insufficient benefits to farmers to adopt perennials at the scale needed to reduce environmental effects. Perennials are generally more complex to manage and, for successful adoption, greater skills are often required than to manage annuals. Experience from the Conservation Reserve Program in the USA to encourage conversion of cropland to perennials indicates that the scale of landscape change achieved (in the order of 5%) is still low. Lessons learnt in both countries from experiences include: (1) careful thought as to where perennials are most needed (targeting); (2) plant development programs targeted at key environments; (3) involvement of farmers in research at the outset to ensure that systems developed are profitable and adoptable; (4) the need for a trialling and learning program; (5) appropriate choice of policy tools to maximise environmental outcomes.

Sign in / Sign up

Export Citation Format

Share Document