scholarly journals Predictive Model of Lake Photic Zone Temperature Across the Conterminous United States

2021 ◽  
Vol 9 ◽  
Author(s):  
B. J. Kreakie ◽  
S. D. Shivers ◽  
J. W. Hollister ◽  
W. B. Milstead
Keyword(s):  
United States ◽  
Air Temperature ◽  
Ambient Air ◽  
Lake Ecosystem ◽  
Lake Area ◽  
Photic Zone ◽  
Final Model ◽  
Lake Ecosystems ◽  
Lake Temperature ◽  
Zone Temperature

As the average global air temperature increases, lake surface temperatures are also increasing globally. The influence of this increased temperature is known to impact lake ecosystems across local to broad scales. Warming lake temperature is linked to disruptions in trophic linkages, changes in thermal stratification, and cyanobacteria bloom dynamics. Thus, comprehending broad trends in lake temperature is important to understanding the changing ecology of lakes and the potential human health impacts of these changes. To help address this, we developed a simple yet robust random forest model of lake photic zone temperature using the 2007 and 2012 United States Environmental Protection Agency’s National Lakes Assessment data for the conterminous United States. The final model has a root mean square error of 1.48°C and an adjusted R2 of 0.88; the final model included 2,282 total samples. The sampling date, that day’s average ambient air temperature and longitude are the most important variables impacting the final model’s accuracy. The final model also included 30-days average temperature, elevation, latitude, lake area, and lake shoreline length. Given the importance of temperature to a lake ecosystem, this model can be a valuable tool for researchers and lake resource managers. Daily predicted lake photic zone temperature for all lakes in the conterminous US can now be estimated based on basic ambient temperature and location information.

Element fluxes in watershed-lake ecosystems recovering from acidification: Čertovo Lake, the Bohemian Forest, 2001–2005

Biologia ◽  
2006 ◽  
Vol 61 (20) ◽  
Author(s):  
Jiří Kopáček ◽  
Jan Turek ◽  
Josef Hejzlar ◽  
Jiří Kaňa ◽  
Petr Porcal
Keyword(s):  
Major Ions ◽  
Nitrogen Saturation ◽  
Ionic Composition ◽  
Base Cations ◽  
Lake Ecosystem ◽  
Lake Area ◽  
Nitrogen Transformations ◽  
Inorganic N ◽  
Microbial Decomposition ◽  
Lake Ecosystems

AbstractFluxes of major ions and nutrients were measured in the watershed-lake ecosystem of a strongly acidified lake, Čertovo jezero (Čertovo Lake), in the 2001 through 2005 hydrological years. Water balance was estimated from precipitation and throughfall amounts, and measured outflow from the lake. The average water input into and outflow from the watershed-lake ecosystem was 1461 mm and 1271 mm (40 L km−2 s−1), respectively, and the water residence time in the lake averaged 662 days. The ecosystem has been recovering from acidification since the late 1980s. Still, however, Čertovo watershed was an average net source of 23 mmol m−2 yr−1 of SO42−. Nitrogen saturation of the watershed caused low retention of the deposited inorganic N (23% on average). After a dry summer in 2003 and a cold winter in 2004, the watershed became a net source of inorganic N (19 mmol m−2 yr−1). Nitrogen transformations and SO42− release were the dominant terrestrial sources of H+ (81 and 47 mmol m−2 yr−1, respectively) and the watershed was a net source of 42 mmol H+ m−2 yr−1. Ionic composition of tributaries showed seasonal variations with the most pronounced changes in NO3−, base cations, DOC, and ionic Al (Ali) concentrations. The in-lake biogeochemical processes reduced the incoming H+ by ∼50% (i.e., neutralized on average 222 mmol H+ m−2 yr−1, on a lake-area basis). Denitrification, SO42− reduction, and photochemical and microbial decomposition of allochthonous organic matter were the most important in-lake H+ consuming processes (215, 85, and 122 mmol H+ m−2 yr−1, respectively), while hydrolysis of Ali was the dominant H+ generating process (96 mmol H+ m−2 yr−1) in Čertovo Lake. Photochemical liberation from organic complexes was an additional in-lake source of Ali. The net in-lake retention or removal of nutrients (carbon, phosphorus, nitrogen, and silica) varied between 18% and 34% of their inputs.

Treatment of a Municipal Leachate Under Multi-Variable Conditions

1982 ◽  
Vol 17 (1) ◽  
pp. 135-148
Author(s):  
P.T. Wong ◽  
D.S. Mavinic
Keyword(s):  
Air Temperature ◽  
Nutrient Loading ◽  
Ambient Air ◽  
Removal Rates ◽  
Ambient Air Temperature

Abstract The treatability of a municipal leachate (BOD5 = 8090 mg/L) was investigated, by aerobic biostabilization, at a nutrient loading of BOD5:N:P of 100:3.2:1.1. The first stage effluents were subsequently polished by lime-magnesium coagulation. The ranges of ambient air temperature and sludge age studied were 5° to 25°C and 5 to 20 days, respectively. In the biostabilization phase, a BOD5:N:P loading of 100:3.2:1.1 was found to be “adequate” for treatment. Organic and metal removals in the first stage units were excellent. Under all conditions investigated, except for the two units close to washout conditions (5-day sludge age units at 5° and 10°C), BOD5 and COD removals of at least 99.4 and 96.4 percent, respectively, were achieved. Similarly, removal rates for most of the metals monitored were greater than 90 percent. In general, the removal of residual contaminants was not enhanced significantly by the addition of magnesium in the lime-magnesium polishing step.

RECONSTRUCTED ANCESTRAL ENZYMES SUGGEST THAT EARTH'S PHOTIC-ZONE TEMPERATURE MARKEDLY DECREASED OVER GEOLOGIC TIME

2016 ◽  
Author(s):  
Amanda Garcia ◽  
◽  
J. William Schopf ◽  
Shin-ichi Yokobori ◽  
Satoshi Akanuma ◽  
...  
Keyword(s):  
Photic Zone ◽  
Geologic Time ◽  
Zone Temperature

scholarly journals Monetizing the Burden of Childhood Asthma Due to Traffic Related Air Pollution in the Contiguous United States in 2010

2021 ◽  
Vol 18 (15) ◽  
pp. 7864
Author(s):  
Minaal Farrukh ◽  
Haneen Khreis
Keyword(s):  
United States ◽  
Air Pollution ◽  
Economic Impact ◽  
Childhood Asthma ◽  
Ambient Air ◽  
The United States ◽  
The State ◽  
Cost Calculation ◽  
Cost Burden ◽  
Incident Cases

Background: Traffic-related air pollution (TRAP) refers to the wide range of air pollutants emitted by traffic that are dispersed into the ambient air. Emerging evidence shows that TRAP can increase asthma incidence in children. Living with asthma can carry a huge financial burden for individuals and families due to direct and indirect medical expenses, which can include costs of hospitalization, medical visits, medication, missed school days, and loss of wages from missed workdays for caregivers. Objective: The objective of this paper is to estimate the economic impact of childhood asthma incident cases attributable to nitrogen dioxide (NO2), a common traffic-related air pollutant in urban areas, in the United States at the state level. Methods: We calculate the direct and indirect costs of childhood asthma incident cases attributable to NO2 using previously published burden of disease estimates and per person asthma cost estimates. By multiplying the per person indirect and direct costs for each state with the NO2-attributable asthma incident cases in each state, we were able to estimate the total cost of childhood asthma cases attributable to NO2 in the United States. Results: The cost calculation estimates the total direct and indirect annual cost of childhood asthma cases attributable to NO2 in the year 2010 to be $178,900,138.989 (95% CI: $101,019,728.20–$256,980,126.65). The state with the highest cost burden is California with $24,501,859.84 (95% CI: $10,020,182.62–$38,982,261.250), and the state with the lowest cost burden is Montana with $88,880.12 (95% CI: $33,491.06–$144,269.18). Conclusion: This study estimates the annual costs of childhood asthma incident cases attributable to NO2 and demonstrates the importance of conducting economic impacts studies of TRAP. It is important for policy-making institutions to focus on this problem by advocating and supporting more studies on TRAP’s impact on the national economy and health, including these economic impact estimates in the decision-making process, and devising mitigation strategies to reduce TRAP and the population’s exposure.

scholarly journals Effects of trees, gardens, and nature trails on heat index and child health: design and methods of the Green Schoolyards Project

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kevin Lanza ◽  
Melody Alcazar ◽  
Deanna M. Hoelscher ◽  
Harold W. Kohl
Keyword(s):  
Physical Activity ◽  
United States ◽  
Relative Humidity ◽  
Air Temperature ◽  
The United States ◽  
Heat Index ◽  
Activity Levels ◽  
Natural Setting ◽  
Physical Activity Levels ◽  
Nature Trails

Abstract Background Latinx children in the United States are at high risk for nature-deficit disorder, heat-related illness, and physical inactivity. We developed the Green Schoolyards Project to investigate how green features—trees, gardens, and nature trails—in school parks impact heat index (i.e., air temperature and relative humidity) within parks, and physical activity levels and socioemotional well-being of these children. Herein, we present novel methods for a) observing children’s interaction with green features and b) measuring heat index and children’s behaviors in a natural setting, and a selection of baseline results. Methods During two September weeks (high temperature) and one November week (moderate temperature) in 2019, we examined three joint-use elementary school parks in Central Texas, United States, serving predominantly low-income Latinx families. To develop thermal profiles for each park, we installed 10 air temperature/relative humidity sensors per park, selecting sites based on land cover, land use, and even spatial coverage. We measured green features within a geographic information system. In a cross-sectional study, we used an adapted version of System for Observing Play and Recreation in Communities (SOPARC) to assess children’s physical activity levels and interactions with green features. In a cohort study, we equipped 30 3rd and 30 4th grade students per school during recess with accelerometers and Global Positioning System devices, and surveyed these students regarding their connection to nature. Baseline analyses included inverse distance weighting for thermal profiles and summing observed counts of children interacting with trees. Results In September 2019, average daily heat index ranged 2.0 °F among park sites, and maximum daily heat index ranged from 103.4 °F (air temperature = 33.8 °C; relative humidity = 55.2%) under tree canopy to 114.1 °F (air temperature = 37.9 °C; relative humidity = 45.2%) on an unshaded playground. 10.8% more girls and 25.4% more boys interacted with trees in September than in November. Conclusions We found extreme heat conditions at select sites within parks, and children positioning themselves under trees during periods of high heat index. These methods can be used by public health researchers and practitioners to inform the redesign of greenspaces in the face of climate change and health inequities.

scholarly journals Ambient Air Temperature Assisted Crystallization for Inorganic CsPbI2Br Perovskite Solar Cells

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3398
Author(s):  
Yi Long ◽  
Kun Liu ◽  
Yongli Zhang ◽  
Wenzhe Li
Keyword(s):  
Solar Cells ◽  
Air Temperature ◽  
High Performance ◽  
Defect Density ◽  
Perovskite Solar Cells ◽  
Ambient Air ◽  
Dark Phase ◽  
High Quality ◽  
Ambient Air Temperature ◽  
Air Atmosphere

Inorganic cesium lead halide perovskites, as alternative light absorbers for organic–inorganic hybrid perovskite solar cells, have attracted more and more attention due to their superb thermal stability for photovoltaic applications. However, the humid air instability of CsPbI2Br perovskite solar cells (PSCs) hinders their further development. The optoelectronic properties of CsPbI2Br films are closely related to the quality of films, so preparing high-quality perovskite films is crucial for fabricating high-performance PSCs. For the first time, we demonstrate that the regulation of ambient temperature of the dry air in the glovebox is able to control the growth of CsPbI2Br crystals and further optimize the morphology of CsPbI2Br film. Through controlling the ambient air temperature assisted crystallization, high-quality CsPbI2Br films are obtained, with advantages such as larger crystalline grains, negligible crystal boundaries, absence of pinholes, lower defect density, and faster carrier mobility. Accordingly, the PSCs based on as-prepared CsPbI2Br film achieve a power conversion efficiency of 15.5% (the maximum stabilized power output of 15.02%). Moreover, the optimized CsPbI2Br films show excellent robustness against moisture and oxygen and maintain the photovoltaic dark phase after 3 h aging in an air atmosphere at room temperature and 35% relative humidity (R.H.). In comparison, the pristine films are completely converted to the yellow phase in 1.5 h.

scholarly journals Application of the Conditional Nonlinear Optimal Perturbations Method in the Shallow Lake Ecological Degradation and Restoration

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Bo Wang ◽  
Qianqian Qi
Keyword(s):  
Shallow Lake ◽  
Sediment Resuspension ◽  
Finite Amplitude ◽  
Water Transparency ◽  
Lake Ecosystem ◽  
Lake Ecosystems ◽  
Ecological Degradation ◽  
Parameter Condition ◽  
Restoration Model ◽  
Simple Combination

In the shallow lake ecosystems, the recovery of the aquatic macrophytes and the increase in the water transparency have been the main contents of the ecological restoration. Using the shallow lake ecological degradation and restoration model, CNOP method is adopted to discuss the instability and sensitivity of the ecosystem to the finite-amplitude perturbations related to the initial condition and the parameter condition. Results show that the linearly stable clear (turbid) water states can be nonlinearly unstable with the finite-amplitude perturbations, which represent the nature factors and the human activities such as the excessive harvest of the macrophytes and the sediment resuspension caused by artificially dynamic actions on the ecosystems. The results also support the viewpoint of Scheffer et al., whose emphasis is that the facilitation interactions between the submerged macrophytes and the water transparency are the main trigger for an occasional shift from a turbid to a clear state. Also, by the comparison with CNOP-I, CNOP-P, CNOP, and (CNOP-I, CNOP-P), results demonstrate that CNOP, which is not a simple combination of CNOP-I and CNOP-P, could induce the shallow lake ecosystem larger departure from the same ground state rather than CNOP-I, CNOP-P, and (CNOP-I, CNOP-P).

Paleoecology of Marine Foraminifera in the Pluvial Estancia Valley, Central New Mexico

1977 ◽  
Vol 7 (2) ◽  
pp. 254-267 ◽  
Author(s):  
F.W. Bachhuber ◽  
W.A. McClellan
Keyword(s):  
New Mexico ◽  
Air Temperature ◽  
Marine Environment ◽  
Developmental Stages ◽  
Geographic Location ◽  
Salinity Range ◽  
Extant Species ◽  
Lake Temperature ◽  
Minimum Depth ◽  
Unusual Occurrence

Two species of marine Foraminifera have been identified in the Quaternary pluvial sequence of the Estancia Valley, central New Mexico. Besides being an unusual occurrence of marine organisms in an inland body of water remote from the marine environment, the Foraminifera yield useful paleolimnological and paleoclimatological information about two major late Wisconsin pluvial lakes. In addition, the geographic location of the Estancia Valley relative to the closest marine environment requires foraminiferal introduction by avian means. Paleontologic evidence verifies the freshwater nature of the pluvial maxima of Late Lake Estancia (18,000-10,500 BP) and Lake Willard (8500-6000 BP) but early lake conditions were considerably different. The occurrence of foraminifers Cribroelphidium selseyense and Protelphidium orbiculare, both extant species, in the sediments from the early part of each pluvial stand indicates that initial lake development was characterized by a salinity range of 25 to 35‰. At these times lake depth approximated 6 m. By comparison, the freshwater maximum of Late Lake Estancia attained a minimum depth of 90 m. The modern holarctic distribution of the Foraminifera could suggest a mean August lake temperature of 10°C during the developmental stages of Late Lake Estancia and Lake Willard. Because of the shallow-water nature of the lake basins it is likely that this temperature was reflective of mean August air temperature. Therefore, a lowering of mean August air temperature of 9.7°C from that of the present is possible.

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