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At least 73 records · Page 4Linked to original sources

USGS2023

Atmospheric correction intercomparison of hyperspectral and multispectral imagery over agricultural study sites

In this research effort we assess the performance of atmospheric correction-based surface reflectance (SR) retrievals from two satellite image sources, one with very high spatial resolution (VHR) (<5-m) and the other high spectral resolution (~10-nm). The VHR images are from MAXARs WorldView-3 (WV3) satellite and the high spectral resolution images are from Agenzia Spaziale Italianas (ASI) PRecursore IperSpettrale della Missione Applicativa (PRISMA) satellite. We use various atmospheric correction (AC) tools to provide intercomparisons of both AC tools and image source SR estimates. The AC tools we evaluated include Fast Line-of-sight Atmospheric Analysis of Hypercubes (FLAASH) within ENVI version 4.7, MODerate resolution atmospheric TRANsmission (MODTRAN) versions 5.3.3 and 6.0, and ASIs Level-2D correction for PRISMA imagery. Prior to correcting WV3 and PRISMA imagery to SR, we performed manual geometric corrections of imagery as both image sources were found to lack consistent georegistration. We performed comparisons at two study sites in Maryland, USA, including the United States Department of Agriculture Beltsville Agricultural Research Center (BARC) and an agricultural study site on Marylands Eastern Shore region. For the BARC site, we used WV3 imagery acquired on 2022-04-02 and PRISMA imagery acquired on 2022-04-28, focusing on evaluation of AC tool SR retrieval performance for each image source separately due to large time differences in image acquisitions where SR values are likely impacted by changing field conditions. For the Eastern Shore site, WV3 imagery was acquired on 2022-05-18 and 2022-05-30, and PRISMA imagery was acquired on 2022-05-21, allowing for quantitative evaluation of both AC tool performance and intercomparison between WV3 and PRISMA imagery. Having WV3 imagery acquired before and after PRISMA imagery allows for interpretation of major changes in field conditions and thus, identification of fields to exclude from intercomparisons. For intercomparison assessments, we computed relative percent difference (RPD) between the AC tool SR retrievals. For image source comparisons, 4-m WV3 pixels were resampled to 30-m PRISMA pixels after which 30-m WV3 bands and PRISMA spectra were compared to one another visually for both study sites. To provide rigorous SR retrieval intercomparisons between image sources, PRISMA spectra were resampled to WV3-equivalent bands for RPD computation for the Eastern Shore site. In addition to the SR retrieval intercomparisons between the AC tools, we carry out a quasi-validation where we retrieve fractional crop residue cover (fR) from the satellite image sources by calculating established spectral indices (SIs) and calibrating SIs with ground-measured fR acquired within several days of satellite overpasses. These SIs include the Cellulose Absorption Index (CAI) (Nagler et al. 2000), Shortwave Infrared Normalized Difference Residue Index (SINDRI) (Serbin et al. 2009), Lignin-Cellulose Absorption Index (LCAI) (Daughtry et al. 2005), and Lignin-Cellulose Peak Center Difference Index (LCPCDI) (Hively et al. 2021) 1-4. The most accurate crop residue SIs are generally based on shortwave infrared (SWIR) reflectance bands ranging from 2000 nm to 2400 nm that measure dry vegetation lignocellulose absorption features at 2100 and 2300 nm 1-5. For instance, the CAI identifies a 2100 nm cellulose absorption feature with a central band positioned on this feature, and two spectrally adjacent bands at 2040 and 2210 nm, while the LCAI identifies the 2300 nm lignin absorption feature compared to bands at 2165 and 2210 nm. Particular focus on intercomparisons for the SWIR region is critical as atmospheric water, carbon dioxide, and methane impact accurate SR retrieval as shown in Figure 1.a. Our final analysis concludes with the selection of the top-performing AC approach between the WV3 and PRISMA imagery (as indicated by low SR RPD) and then compares PRIMSA and 30-m WV3 imagery with original 4-m WV3 imagery to assess the degree to which spatial resolution impacts the retrieval of fR. Figure 1 provides a comparative example of WV3 and PRISMA imagery used to compute SINDRI which is then calibrated to fR using second order polynomial equations from Hively et al. (2018) 6. Figure 1 fR calibrations will be updated with newly acquired ground survey data from May 2022 to further improve the accuracy of image source and AC tool intercomparisons.

Conference Paper↗

USGS2020

Regional coordination between riparian dependence and atmospheric demand in willows (Salix L.) of western North America

Aim Plants vary in their hydrological and climatic niches. How these niche dimensions covary among closely related species can help identify co‐adaptations to hydrological and climatic factors, as well as predict biodiversity responses to environmental change. Location Western United States. Methods Relationships between riparian dependence and climate niches of willows ( Salix L.) were assessed, incorporating phylogenetics and functional traits to understand the adaptive nature of those relationships. The riparian dependence niche was estimated as the mean distance between georeferenced occurrence records and the nearest stream based on the National Hydrography Database. Results were compared to oaks ( Quercus L.), a less riparian‐dependent clade, with the expectation of different niche relationships. Results Willows generally occurred closer to streams than expected by chance, but riparian dependence varied substantially among species. Riparian dependence was positively correlated with mean annual temperature and diurnal temperature range niche, both indicators of atmospheric demand on evapotranspiration. Phylogenetic independent contrast correlations for these relationships were significant as well, and the high degree of niche convergence among species indicated evolutionarily labile co‐adaptations to riparian dependence and atmospheric demand. Plant height increased with mean annual temperature niche, and specific leaf area increased with residual variation in height, indicating underlying morphological correlates of niche variation. Oaks, on the other hand, exhibited no relationship between atmospheric demand and riparian dependence, and weaker niche relationships with riparian dependence overall. Main conclusions These results support the assertion that hydric‐adapted, woody riparian plants compensate for increased atmospheric demand on transpiration with a reliable supply of water provided by riparian habitats and that this trade‐off may be unique from mesic–xeric woody plants. Conservation of warm‐adapted riparian trees and shrubs under increasing temperatures and atmospheric demand may necessitate reversal of groundwater depletion. Cool‐adapted species may be best conserved through maintenance or expansion of riparian buffers as they become more riparian obligate with warming.

Diversity and Distributions↗

USGS2000

Coupled atmosphere-biophysics-hydrology models for environmental modeling

The formulation and implementation of LEAF-2, the Land Ecosystem–Atmosphere Feedback model, which comprises the representation of land–surface processes in the Regional Atmospheric Modeling System (RAMS), is described. LEAF-2 is a prognostic model for the temperature and water content of soil, snow cover, vegetation, and canopy air, and includes turbulent and radiative exchanges between these components and with the atmosphere. Subdivision of a RAMS surface grid cell into multiple areas of distinct land-use types is allowed, with each subgrid area, or patch, containing its own LEAF-2 model, and each patch interacts with the overlying atmospheric column with a weight proportional to its fractional area in the grid cell. A description is also given of TOPMODEL, a land hydrology model that represents surface and subsurface downslope lateral transport of groundwater. Details of the incorporation of a modified form of TOPMODEL into LEAF-2 are presented. Sensitivity tests of the coupled system are presented that demonstrate the potential importance of the patch representation and of lateral water transport in idealized model simulations. Independent studies that have applied LEAF-2 and verified its performance against observational data are cited. Linkage of RAMS and TOPMODEL through LEAF-2 creates a modeling system that can be used to explore the coupled atmosphere–biophysical–hydrologic response to altered climate forcing at local watershed and regional basin scales.

Journal of Applied Meteorology↗

USGS2014

Tritium and deuterium content of atmospheric hydrogen

The tritium and deuterium content of 24 samples of atmospheric hydrogen collected at ground level near Buffalo. N.Y. (U.S.A.). Hamburg (Germany), and Nürnberg (Germany) during 1954 to 1956 was measured. At the beginning of 1954 the T/H-ratio was found to have been 9.18 · 10 -14 i.e. about a factor of 10 higher than 1949 (FALTINGS and HARTECK) and 1951 (v. GROSSE et al.), probably due to the first explosion of a thermonuclear device in November 1952. In spite of a major test series of thermonuclear weapons in spring of 1954 (Operation CASTLE) no further increase in the tritium content was found during 1954 and 1955. It shows instead a seasonal variation with low tritium content in summer and about a threefold higher one in winter. Simultaneously, there is a good correlation between the tritium and deuterium concentrations. From 1956 on a noticeable increase in the tritium content due to more man-made HT produced or released by thermonuclear devices into the atmosphere was found, in agreement with measurements by GONSIOR. A possible explanation of the experimental results as well as a mode to test the validity of the model suggested is given. The deuterium concentrations of the samples analysed vary between about +7 percent and –17 percent, compared to Standard Lake Michigan Water with a ratio D/H = 0.0148 ± 0.0002 mol percent. Although from these results only a correlation factor between the tritium and deuterium content of “mean atmospheric hydrogen” and not their absolute values can be derived it is obvious that atmospheric hydrogen and the water vapour of the atmosphere are not in thermodynamic equilibrium, as has been pointed out before by HARTECK and SUESS.

Zeitschrift fur Naturforschung A↗

USGS2006

Water resources of Monroe County, New York, water years 2000-02: Atmospheric deposition, ground water, streamflow, trends in water quality, and chemical loads in streams

This report, the fifth in a series that presents analyses of the hydrologic data collected in Monroe County since 1984, interprets data from four surface-water-monitoring sites in the Irondequoit Creek basin (Irondequoit Creek at Railroad Mills, East Branch Allen Creek at Pittsford, Allen Creek near Rochester, and Irondequoit Creek above Blossom Road); and from three sites on tributaries to the Genesee River (Oatka Creek at Garbutt, Honeoye Creek at Honeoye Falls, and Black Creek at Churchville) and from the Genesee River at Charlotte Docks. It also interprets data from a site on Northrup Creek, which provides information on nutrient loads delivered to Long Pond, a small eutrophic embayment of Lake Ontario. The report also includes water-level and water-quality data from nine observation wells in Ellison Park, and atmospheric-deposition data from a collection site at Mendon Ponds. Atmospheric Deposition : Average annual precipitation for 2000–02 was 33.11 in., 0.94 in. below normal. Average annual loads of some chemical constituents in atmospheric deposition for 2000–02 differed considerably from those for the previous period of record. Loads of all nutrients except ammonia decreased by amounts ranging from 28 percent (ammonia + organic nitrogen and phosphorus) to 2 percent (nitrite + nitrate), whereas ammonia loads an increased by 8 percent. Loads of dissolved sodium and total zinc in atmospheric deposition increased by 56 percent, and 54, percent respectively, over the previous period of record. Average annual loads of other constituents showed decreases ranging from 41 percent (dissolved magnesium) to 17 percent (dissolved chloride). Loads of all nutrients deposited in the Irondequoit Creek basin from atmospheric sources during 2000–02 greatly exceeded those transported by Irondequoit Creek. The ammonia load deposited in the basin was 165 times the load transported at Blossom Road (the most downstream site); the ammonia + organic nitrogen load was 2.8 times greater, orthophosphate 9.7 times greater, total phosphorus 1.2 times greater, and the nitrite + nitrate load was 1.6 times greater. Average yields of dissolved chloride and dissolved sulfate from atmosphoric sources were much less than those transported by streamflow at Blossom Road—chloride was about 1.5 percent and sulfate about 9.1 percent of the amount transported by Irondequoit Creek. Ground water : Ground-water-levels and water quality data were collected from 9 observation wells in Ellison Park in Monroe County. All wells except Mo 2 and Mo 659 are in the flood plain of Irondequoit Creek. Water levels indicate frequent reversals in direction of lateral flow toward or away from Irondequoit Creek, and all wells except Mo2 and Mo 659 respond to water level fluctuations in the Creek. Trend tests on water levels for the period of record indicate a slight upward trend in water levels at all nine wells, two of which (Mo 3 and Mo 667) were statistically significant. Concentrations of ammonia and ammonia + organic nitrogen showed a general decrease for the current period of record. Total phosphorus concentrations showed an increase at four wells and a decrease at four wells. Water quality data showed that the highest median concentrations of nutrients continues to occur in Mo 667 and the highest median concentrations of common ions was at Mo 664. Streamflow : Statistical analysis of long-term (greater than 15 years) streamflow records for unregulated streams in Monroe County indicated that annual mean flows for water years (A water year is the 12-month period from October 1 through September 30 of the following year.) 2000–02 generally were in the normal range (75th to 25th percentile), although Allen Creek continued to show a significant downward trend in mean monthly streamflow during the 1984–2002 water years. Chemical Concentration in Streams : Concentrations of several constituents in streams of the Irondequoit Creek basin showed statistically significant (α = 0.05) trends from the beginning of their period of record through 2002. Three of the four Irondequoit Creek sites (Allen Creek, Blossom Road, and Railroad Mills) showed downward trends in ammonia (4.6 to 12.0 percent per year) and ammonia + organic nitrogen (2.8 to 5.3 percent per year). Allen Creek showed downward trends in nitrite + nitrate and total phosphorus (both 1.2 percent per year), and Irondequoit Creek above Blossom Road showed an upward trend in orthophosphate (1.8 percent per year). Three Irondequoit Creek sites showed upward trends in dissolved chloride: Railroad Mills (4.8 percent per year), Allen Creek, and Blossom Road (both 1.9 percent per year). Allen Creek showed a downward trend in sulfate of 0.98 percent per year, whereas Blossom Road showed a downward trend in suspended solids of 4.0 percent per year. Volatile suspended solids showed an upward trend of 3.2 percent per year at Allen Creek and a downward trend of 2.2 percent per year at Blossom Road. Northrup Creek in western Monroe County, showed significant downward trends in concentrations of volatile suspended solids (2.5 percent per year), total phosphorus (5.3 percent per year), and orthophosphate (9.9 percent per year). The Genesee River at Charlotte Docks showed downward trends in volatile suspended solids (2.1 percent per year) and ammonia + organic nitrogen (4.5 percent per year). Oatka Creek at Garbutt showed an upward trend of 21.4 percent per year in turbidity. Chemical Loads in Streams : Mean annual yields (pounds or tons per square mile) of many constituents at the Irondequoit Creek sites were lower than those in previous reporting periods. Suspended solids and nitrite + nitrate yields were lower at three of the sites, and yields of volatile suspended solids, ammonia, and total phosphorus were lower at two of the sites. East Branch Allen Creek showed lower yields for five of the nine constituents for 2000–02, than for previous reporting periods. The decreased yields at East Branch Allen Creek are likely due to the Jefferson Road stormflow-detention basin and the much lower than normal runoff for the 2000–02 period.

New York↗

USGS2001

Water resources of Monroe County, New York, water years 1994-96, with emphasis on water quality in the Irondequoit Creek basin: Atmospheric deposition, ground water, streamflow, trends in water quality, and chemical loads to Irondequoit Bay

Irondequoit Creek drains 169 square miles in the eastern part of Monroe County. Nutrients transported by Irondequoit Creek to Irondequoit Bay on Lake Ontario have contributed to the eutrophication of the Bay. Sewage-treatment-plant effluent, a major source of nutrients to the creek and its tributaries, was eliminated from the basin in 1979 by diversion to a regional wastewater-treatment facility, but sediment and contaminants from nonpoint sources continue to enter the creek and Irondequoit Bay. This report analyzes data from five surface-water monitoring sites in the Irondequoit Creek basin. Irondequoit Creek at Railroad Mills, East Branch Allen Creek at Pittsford, Allen Creek near Rochester, Irondequoit Creek at Blossom Road, and Irondequoit Creek at Empire Boulevard. It is the third in a series of reports that present interpretive analyses of the hydrologic data collected in Monroe County since 1984. Also included are data from a site on Northrup Creek, which drains a 23.5-square-mile basin west of the Genesee River in western Monroe County, to provide information on surface-water quality in a stream west of the Genesee River and on loads of nutrients delivered to Long Pond, a small eutrophic embayment of Lake Ontario, and data from the Genesee River for comparison of historical water-quality conditions with 1994-96 conditions. Water-level and water-quality data from nine observation wells in Ellison Park, and atmospheric-deposition data from Mendon Ponds, also are included. Average annual yields of chemical constituents from atmospheric deposition for 1994-96 were generally similar to those for the previous 10 years (1984-93), except for dissolved sodium, dissolved potassium, total phosphorus, and orthophosphate, which ranged from 42 percent (dissolved sodium) to 275 percent (dissolved potassium) greater than during 1984-93, and dissolved sulfate and ammonia, which were about 30 percent less than in 1984-93. Loads of all nutrients deposited in the Irondequoit Creek basin from atmospheric sources during water years 1994-96 exceeded those removed by Irondequoit Creek at Blossom Road—ammonia by 5,600 percent, orthophosphate by 2,500 percent, ammonia + organic nitrogen by 350 percent, total phosphorus by 300 percent and nitrite + nitrate by 140 percent. Average yields of dissolved chloride and dissolved sulfate from atmospheric deposition were much less than those transported in streamflow—yields of dissolved chloride from atmospheric sources were only 1.9 percent, and yields of sulfate were only 9.2 percent, of those transported in streamflow at Blossom Road. Concentrations of several chemical constituents in streams of the Irondequoit Creek basin showed statistically significant trends from the beginning of their period of record through 1996. The constituents that showed the greatest number of statistically significant trends were dissolved chloride, ammonia, and ammonia + organic nitrogen. Dissolved chloride showed an upward trend at Blossom Road, Allen Creek, and Empire Boulevard and a downward trend at Railroad Mills. Ammonia showed downward trends at Allen Creek, Blossom Road and Railroad Mills. Ammonia + organic nitrogen showed a downward trend at Allen Creek, Blossom Road, and Empire Boulevard. Nitrite + nitrate showed a downward trend at Allen Creek, and orthophosphate showed an upward trend at that site. Turbidity and total suspended solids showed a downward trend at Empire Boulevard. Neither total phosphorus nor volatile suspended solids showed statistically significant trends in concentration at any of the Irondequoit basin sites. Northrup Creek showed a downward trend in total suspended solids and ammonia + organic nitrogen, and an upward trend in dissolved chloride. The Genesee River showed a downward trend in ammonia + organic nitrogen and chloride, and an upward trend in orthophosphate. Most constituents for the 1994-96 water years showed lower average yields at Blossom Road than for the 1989-93 water years, but dissolved chloride showed higher yields for the 1994-96 water years at all sites except Blossom Road. Ammonia + organic nitrogen and total phosphorus showed a decrease in yield at all sites after 1993, and nitrite + nitrate showed slightly higher yields for 1994-96 at the upstream, predominantly rural sites, and lower yields at the downstream, more urban sites, than during 1989-93. The trends and changes in surface-water quality after 1993 can be attributed to several factors within the basin, including land-use changes, annual and seasonal variations in streamflow, and year-to-year variations in the application of deicing salts on area roads. Statistical analyses of long-term (9 years or more) streamflow records of three unregulated streams in Monroe County indicate that annual mean flows for water years 1994-96 were in the normal range (75th to 25th percentile), although Allen Creek showed a statistically significant downward trend in monthly mean streamflow over the 1984-96 water years.

New York↗

USGS1999

Water resources of Monroe County, New York, water years 1989-93, with emphasis on water quality in the Irondequoit Creek basin: Part 2. Atmospheric deposition, ground water, streamflow, trends in water quality, and chemical loads to Irondequoit Bay

Irondequoit Creek, which drains 169 square miles in the eastern part of Monroe County, has been recognized as a source of contaminants that contribute to the eutrophication of Irondequoit Bay on Lake Ontario. The discharge from sewage-treatment plants to the creek and its tributaries was eliminated in 1979 by diversion to another wastewater-treatment facility, but sediment and nonpoint-source pollution remain a concern. This report presents data from five surface-water sites in the Irondequoit Creek basin. Irondequoit Creek at Railroad Mills, East Branch Allen Creek, Allen Creek near Rochester, Irondequoit Creek at Blossom Road, and Irondequoit Creek at Empire Boulevard, to supplement published data from 1984-88. Data from Northrup Creek, which drains 11.7 square miles in western Monroe County, provide information on surface-water quality west of the Genesee River. Also presented are water-level and water-quality data from 12 observation-well sites in Ellison and Powdermill Parks and atmospheric-deposition data from 1 site (Mendon Ponds). Concentrations of several chemical constituents in streams of the Irondequoit Creek basin showed statistically significant trends during 1989-93. Concentrations of total suspended-solids and volatile suspended-solids in Irondequoit Creek at Blossom Road decreased 13.5 and 12.5 percent per year, respectively, and those at Empire Boulevard decreased 33.5 and 22 percent per year, respectively. Concentrations of ammonia plus organic nitrogen increased 17.6 percent per year at one site in the basin, but decreased 8.5 and 22.3 percent per year at two sites. Nitrite plus nitrate decreased at only one site (3.5 percent per year). Concentrations of total phosphorus increased at two sites (about 7 percent per year) and decreased at two other sites (7.6 and 29.9 percent per year), and orthophosphate concentrations increased at one site (10.8 percent per year). Dissolved chloride increased at three sites (1.7 to 10.9 percent per year), and dissolved sulfate decreased at one site (2.1 percent per year) and increased at one site (6.8 percent per year). Median concentrations of constituents were significantly lower in atmospheric deposition than in streamflow, although annual deposition of ammonia nitrogen, nitrite plus nitrate, total phosphorus, and orthophosphate in the basin exceeded the amounts removed by streamflow. Atmospheric deposition of chloride and sulfate, by contrast, represented only 1 and 12 percent, respectively, of the loads transported by Irondequoit Creek (Blossom Road site). Comparison of water-quality data from the Allen Creek site and Irondequoit Creek at Blossom Road from water years 1989-93 with corresponding data from 1984-88 indicates significant changes in median concentrations of several constituents. The concentration of dissolved chloride increased at Blossom Road and was unchanged at Allen Creek, whereas sulfate decreased at both sites. Concentrations of ammonia plus organic nitrogen, and nitrite plus nitrate, were significantly lower during 1989-93 than during 1984-88 at both sites. Total phosphorus concentration was lower during 1984-88 than during 1989-93 at Blossom Road but showed no change at Allen Creek, and orthophosphate concentration for 1989-93 was lower than in 1984-88 at both sites. Comparison of chemical loads in atmospheric deposition also indicates significant changes in many constituents. Five-year-mean loads of sodium, sulfate, and lead in atmospheric deposition for 1989-93 exceeded those for 1984-88, whereas 5-year-mean loads of calcium, magnesium, potassium, chloride, nitrite plus nitrate, ammonia nitrogen, and orthophosphate for 1989-93 were lower than in 1984-88. The changes in surface-water quality resulted from several factors within the basin, including land-use changes, annual and seasonal variations in streamflow, and year-to-year variations in the application of deicing salts on area roads. Statistical analyses of long-term (9 years or more) flow records of three unregulated streams in Monroe County indicate that annual mean flows for water years 1989- 93 were in the normal range (20th- to 80th-percentile). The greatest mean annual flow in this period-about 140 percent of normal at Irondequoit Creek and Black Creek-occurred in 1993, but the annual mean flow for that water year at Allen Creek was only 98 percent of normal. The lowest annual mean flows of these streams-ranging from 75 percent of normal to 93 percent of normal-occurred in 1989. The average annual mean flows for these streams for 1989-93 was 104 percent of normal, and that for 1984-88 was normal.

New York↗

USGS2015

Carbon exchange between the atmosphere and subtropical forested cypress and pine wetlands

Carbon dioxide exchange between the atmosphere and forested subtropical wetlands is largely unknown. Here we report a first step in characterizing this atmospheric–ecosystem carbon (C) exchange, for cypress strands and pine forests in the Greater Everglades of Florida as measured with eddy covariance methods at three locations (Cypress Swamp, Dwarf Cypress and Pine Upland) for 2 years. Links between water and C cycles are also examined at these three sites, as are methane emission measured only at the Dwarf Cypress site. Each forested wetland showed net C uptake from the atmosphere both monthly and annually, as indicated by the net ecosystem exchange (NEE) of carbon dioxide (CO 2 ). For this study, NEE is the difference between photosynthesis and respiration, with negative values representing uptake from the atmosphere that is retained in the ecosystem or transported laterally via overland flow (unmeasured for this study). Atmospheric C uptake (NEE) was greatest at the Cypress Swampp (−900 to −1000 g C m 2 yr −1 ), moderate at the Pine Upland (−650 to −700 g C m 2 yr −1 ) and least at the Dwarf Cypress (−400 to −450 g C m 2 yr −1 ). Changes in NEE were clearly a function of seasonality in solar insolation, air temperature and flooding, which suppressed heterotrophic soil respiration. We also note that changes in the satellite-derived enhanced vegetation index (EVI) served as a useful surrogate for changes in NEE at these forested wetland sites.

Florida↗

USGS2022

Impacts of the ocean-atmosphere coupling into the very short range prediction system during the impact of Hurricane Matthew on Cuba

The main goal of this investigation is analyzing the impact of insert the ocean-atmosphere coupling into the very short range prediction system of Cuba. The ocean-atmosphere coupled components of the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System are used for this purpose and the hurricane Matthew is selected as study case. Two experiments are performed: first, using a dynamic sea surface temperature, updated daily in the atmospheric model WRF; and second using adynamic coupling between the atmospheric and an oceanic models. For the simulated track, the best results are obtained with the coupled system. The impact of coupling on the maximum wind velocities and minimum central pressure is studied. In the coupled system the sea surface temperature has more influence in the surface latent heat fluxes. Also, with this methodology the dry footprint and the behavior of the precipitation field in the presence of a hurricane are studied. This analysis shows that the hurricane acts like an open and self-sustained system in the numerical experiments. The highest differences in the precipitation simulations are in the significant convective area inside the hurricane.

Ciência e Natura↗

USGS2022

Analysis of ocean dynamics during the impact of Hurricane Matthew using ocean-atmosphere coupling

The main goal of this investigation is to improve the understanding of ocean-atmosphere coupling during hurricanes. The present work involves the integration of the ocean-atmosphere coupled components of the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System in the Very Short Term Prediction System (SisPI). Three experiments are performed: First, using a dynamic sea surface temperature, consistent with the daily updated atmospheric model Weather Research and Forecast (SisPI); second, using the Regional Oceanic Modeling System and third, using a dynamic coupling between the atmospheric and the oceanic models. The coupled system improves the tracks of the hurricane simulations respect to the SisPI. The use of the oceanic model allows a more detailed representation of the sea surface temperature. Using the coupled model, a more precise diurnal cycle of the surface net heat fluxes is obtained.

Cuban Journal of Meteorology (Revista Cubana de Me↗

USGS1993

Diffusional limits to the consumption of atmospheric methane by soils

Net transport of atmospheric gases into and out of soil systems is primarily controlled by diffusion along gas partial pressure gradients. Gas fluxes between soil and the atmosphere can therefore be estimated by a generalization of the equation for ordinary gaseous diffusion in porous unsaturated media. Consumption of CH4 by methylotrophic bacteria in the top several centimeters of soil causes the uptake of atmospheric CH4 by aerated soils. The capacity of the methylotrophs to consume CH4 commonly exceeds the potential of CH4 to diffuse from the atmosphere to the consumers. The maximum rate of uptake of atmospheric CH4 by soil is, therefore, limited by diffusion and can be calculated from soil physical properties and the CH4 concentration gradient. The CH4 concentration versus depth profile is theoretically described by the equation for gaseous diffusion with homogeneous chemical reaction in porous unsaturated media. This allows for calculation of the in situ rate of CH4 consumption within specified depth intervals.

Conference Paper↗

USGS2015

Spatial patterns of atmospheric deposition of nitrogen and sulfur using ion-exchange resin collectors in Rocky Mountain National Park, USA

Lakes and streams in Class 1 wilderness areas in the western United States (U.S.) are at risk from atmospheric deposition of nitrogen (N) and sulfur (S), and protection of these resources is mandated under the Federal Clean Air Act and amendments. Assessment of critical loads, which are the maximum exposure to pollution an area can receive without adverse effects on sensitive ecosystems, requires accurate deposition estimates. However, deposition is difficult and expensive to measure in high-elevation wilderness, and spatial patterns in N and S deposition in these areas remain poorly quantified. In this study, ion-exchange resin (IER) collectors were used to measure dissolved inorganic N (DIN) and S deposition during June 2006–September 2007 at approximately 20 alpine/subalpine sites spanning the Continental Divide in Rocky Mountain National Park. Results indicated good agreement between deposition estimated from IER collectors and commonly used wet + dry methods during summer, but poor agreement during winter. Snowpack sampling was found to be a more accurate way of quantifying DIN and S deposition during winter. Summer DIN deposition was significantly greater on the east side of the park than on the west side (25–50%; p ≤ 0.03), consistent with transport of pollutants to the park from urban and agricultural areas to the east. Sources of atmospheric nitrate (NO 3 − ) were examined using N isotopes. The average δ 15 N of NO 3 − from IER collectors was 3.5&permil; higher during winter than during summer ( p < 0.001), indicating a seasonal shift in the relative importance of regional NO x sources, such as coal combustion and vehicular sources of atmospheric NO 3 − . There were no significant differences in δ 15 N of NO 3 − between east and west sides of the park during summer or winter ( p = 0.83), indicating that the two areas may have similar sources of atmospheric NO 3 − . Results from this study indicate that a combination of IER collectors and snowpack sampling can be used to characterize spatial variability in DIN and S deposition in high-elevation wilderness areas. These data can improve our ability to model critical loads by filling gaps in geographic coverage of deposition monitoring/modeling programs and thus may enable policy makers to better protect sensitive natural resources in Class 1 Wilderness areas.

Colorado↗

USGS2018

Spatial patterns and temporal changes in atmospheric-mercury deposition for the midwestern USA, 2001–2016

Spatial patterns and temporal changes in atmospheric-mercury (Hg) deposition were examined in a five-state study area in the Midwestern USA where 32% of the stationary sources of anthropogenic Hg emissions in the continental USA were located. An extensive monitoring record for wet and dry Hg deposition was compiled for 2001–2016, including 4666 weekly precipitation samples at 13 sites and 27 annual litterfall-Hg samples at 7 sites. This study is the first to examine these Hg data for the Midwestern USA. The median annual precipitation-Hg deposition at the study sites was 10.4 micrograms per square meter per year (ug/m2/year) and ranged from 5.8 ug/m2/year to 15.0 ug/m2/year. The median annual Hg concentration was 9.4 ng/L. Annual litterfall-Hg deposition had a median of 16.1 ug/m2/year and ranged from 9.7 to 23.4 ug/m2/year. Isopleth maps of annual precipitation-Hg deposition indicated a recurring spatial pattern similar to one revealed by statistical analysis of weekly precipitation-Hg deposition. In that pattern, high Hg deposition in southeastern Indiana was present each year, frequently extending to southern Illinois. Most of central Indiana and central Illinois had similar Hg deposition. Areas with comparatively lower annual Hg deposition were observed in Michigan and Ohio for many years and frequently included part of northern Indiana. The area in southern Indiana where high Hg deposition predominated had the highest number of extreme episodes of weekly Hg deposition delivering up to 15% of the annual Hg load from precipitation in a single week. Modeled 48-h back trajectories indicated air masses for these episodes often arrived from the south and southwest, crossing numerous stationary sources of Hg emissions releasing from 23 to more than 300 kg Hg per year. This analysis suggests that local and regional, rather than exclusively continental or global Hg emissions were likely contributing to the extreme episodes and at least in part, to the spatial patterns of precipitation-Hg deposition in the study area. Statistically significant temporal decreases in weekly precipitation-Hg concentrations in the study area between the periods 2001–2013 and 2014–2016 were observed, coinciding with reported reductions in Hg emissions in the USA required by implementation of national Hg emissions-control rules. These decreases in atmospheric-Hg concentrations are believed to have resulted in the reduced atmospheric-Hg deposition recorded because precipitation depths between the two periods were not significantly different. The Hg-monitoring data for the study area identified an atmospheric deposition response to decreased local and regional Hg emissions.

Illinois, Indiana, Kentucky, Michigan, Ohio↗

USGS2016

Assessing atmospheric concentration of polychlorinated biphenyls (PCBs) by evergreen Rhododendron maximum next to a contaminated stream

Conifers are often used as an “air passive sampler”, but few studies have focused on the implication of broadleaf evergreens to monitor atmospheric semivolatile organic compounds such as polychlorinated biphenyls (PCBs). In this study, we used Rhododendron maximum (rhododendron) growing next to a contaminated stream to assess atmospheric PCB concentrations. The study area was located in a rural setting and approximately 2 km downstream of a former Sangamo-Weston (S-W) plant. Leaves from the same mature shrubs were collected in late fall 2010, and winter and spring 2011. PCBs were detected in the collected leaves suggesting that rhododendron can be used as air passive samplers in rural areas where active sampling is impractical. Estimated ΣPCB (47 congeners) concentrations in the atmosphere decreased from fall 2010 to spring 2011 with concentration means at 3990, 2850, and 931 pg m -3 in fall 2010, winter 2011, and spring 2011, respectively. These results indicate that the atmospheric concentrations at this location continue to be high despite termination of active discharge from the former S-W plant. Leaves had a consistent pattern of high concentrations of tetra- and penta-CBs similar to the congener distribution in polyethylene (PE) passive samplers deployed in the water column suggesting that volatilized PCBs from the stream were the primary source of contaminants in rhododendron leaves.

South Carolina↗

USGS2018

Linking transit times to catchment sensitivity to atmospheric deposition of acidity and nitrogen in mountains of the western United States

Transit times are hypothesized to influence catchment sensitivity to atmospheric deposition of acidity and nitrogen (N) because they help determine the amount of time available for infiltrating precipitation to interact with catchment soil and biota. Transit time metrics, including fraction of young water ( F yw ) and mean transit time (MTT), were calculated for 11 headwater catchments in mountains of the western United States based on differences in the amplitude of the seasonal signal of δ 18 O in streamflow and precipitation. Results were statistically compared with catchment characteristics to elucidate controlling mechanisms. Transit times also were compared with stream solute concentrations to test the hypothesis that transit times are a primary influence on weathering rates and biological assimilation of atmospherically deposited N. Results indicate that transit times in the study catchments are strongly related to soil, vegetation, and topographic characteristics, with barren terrain (bare rock and talus) and steep slopes linked to high F yw and short MTT, whereas forest soil (hydrogroup B) was linked to low F yw and greater MTT. Concentrations of silicate weathering products (Na + and Si) were negatively related to F yw and barren terrain, and positively related to MTT and forest soil, supporting the concept that weathering fluxes and buffering capacity tend to be low in alpine areas due to short transit times. Nitrate concentrations were positively related to N deposition, catchment slope, and barren terrain, and negatively related to forest, indicating that hydrologic and/or biogeochemical processes associated with steep slopes limit uptake of atmospherically deposited N by biota. Interannual and seasonal variability in transit times and source water contributions in the study catchments was substantial, reflecting the influence of strong temporal variations in snowmelt inputs in high‐elevation catchments of the western United States. Results from this study confirm that short transit times in these areas are a key reason they are highly sensitive to atmospheric pollution and climate change.

Hydrological Processes↗

USGS2021

The concept of evanescent microbial ecosystems in Earth's atmosphere

This essay presents the hypothesis that short-lived or evanescent microbial ecosystems exist in Earth’s lower troposphere (~ < 4 km). This hypothesis is supported by culture- and molecular-based studies that have shown diverse, viable, and metabolically active microbial communities within Earth’s atmospheric boundary layer. Surprisingly, microorganisms are routinely recovered in samples collected at extreme altitudes including those within the stratosphere (> 18 km). Volcanic eruptions, dust storms, fires, and sea spray are known to seed the atmosphere with microorganisms and to serve as potential nutrient sources while in the atmosphere and upon deposition. Recent research has demonstrated that microorganisms are metabolically active in clouds; for example, archaea capable of utilizing gases such as methane and hydrogen-nitrogen have been identified in clouds and in the atmosphere over natural and anthropogenic gas seeps. The only difference between this hypothesized ecosystem to more traditionally defined ecosystems is its evanescent characteristics where clouds or gas plumes eventually dissipate as they reside over and traverse Earth’s terrestrial and/or aquatic environments. The life cycle of these hypothesized evanescent airborne ecosystems would be short-lived relative to the classically defined biomes or ecosystems.

Book chapter↗

USGS2019

Isotopic evidence that nitrogen enrichment intensifies nitrogen losses to the atmosphere from subtropical mangroves

Nitrogen (N) enrichment can have large effects on mangroves’ capacity to provide critical ecosystem services by affecting fundamental functions such as N cycling and primary productivity. However, our understanding of excess N input effects on N cycling in mangroves remains quite limited. To advance our understanding of how N enrichment via water or air pollution affects mangroves, we evaluated whether increasing N inputs would decrease biological N fixation (BNF), but intensify N dynamics and N losses to the atmosphere in these systems. We measured N concentrations in sediment and vegetation, rates of BNF in sediment and litter, and net sediment ammonification and nitrification rates. We also evaluated long-term integrated N dynamics and N losses to the atmosphere using the natural abundance of N stable isotopes (δ 15 N) in the sediment–plant system and in estuarine water. We performed these analyses at non-N-enriched and N-enriched (that is, polluted) fringe and basin mangroves in southeastern Brazil. The δ 15 N in the sediment–plant system was higher at N-enriched than non-N-enriched fringe sites, indicating increased N losses to the atmosphere from N-enriched sites. However, N concentrations in sediment and vegetation were similar or lower at N-enriched relative to non-N-enriched sites. BNF and net ammonification and nitrification rates were also similar between N-enriched and non-N-enriched sites. Excess N inputs intensified N losses to the atmosphere from mangroves, but N pools, BNF, and net ammonification and nitrification rates were not affected by N enrichment, likely because excess N was quickly lost from the system by direct denitrification and volatilization.

São Paulo↗

USGS2009

Compositional changes in sediments of subalpine lakes, Uinta Mountains (Utah): Evidence for the effects of human activity on atmospheric dust inputs

Sediments in Marshall and Hidden Lakes in the Uinta Mountains of northeastern Utah contain records of atmospheric mineral-dust deposition as revealed by differences in mineralogy and geochemistry of lake sediments relative to Precambrian clastic rocks in the watersheds. In cores spanning more than a thousand years, the largest changes in composition occurred within the past approximately 140 years. Many elements associated with ore deposits (Ag, As, Bi, Cd, Cu, In, Mo, Pb, S, Sb, Sn, and Te) increase in the lake sediments above depths that correspond to about AD 1870. Sources of these metals from mining districts to the west of the Uinta Mountains are suggested by (1) the absence of mining and smelting of these metals in the Uinta Mountains, and (2) lower concentrations of most of these elements in post-settlement sediments of Hidden Lake than in those of Marshall Lake, which is closer to areas of mining and the densely urbanized part of north-central Utah that is termed the Wasatch Front, and (3) correspondence of Pb isotopic compositions in the sediments with isotopic composition of ores likely to have been smelted in the Wasatch Front. A major source of Cu in lake sediments may have been the Bingham Canyon open-pit mine 110 km west of Marshall Lake. Numerous other sources of metals beyond the Wasatch Front are likely, on the basis of the widespread increases of industrial activities in western United States since about AD 1900. In sediment deposited since ca. AD 1945, as estimated using 239+240 Pu activities, increases in concentrations of Mn, Fe, S, and some other redox-sensitive metals may result partly from diagenesis related to changes in redox. However, our results indicate that these elemental increases are also related to atmospheric inputs on the basis of their large increases that are nearly coincident with abrupt increases in silt-sized, titanium-bearing detrital magnetite. Such magnetite is interpreted as a component of atmospheric dust, because it is absent in catchment bedrock. Enrichment of P in sediments deposited after ca. AD 1950 appears to be caused largely by atmospheric inputs, perhaps from agricultural fertilizer along with magnetite-bearing soil.

Utah↗