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At least 577 records · Page 32Linked to original sources
USGS1991

Offshore and onshore liquefaction at Moss Landing spit, central California, - result of the October 17, 1989, Loma Prieta earthquake

As a result of the October 17, 1989, Loma Prieta (Santa Cruz Mountains, California) earthquake, liquefaction of the fluvial, estuarine, eolian, and beach sediments under a sand spit destroyed the Moss Landing Marine Laboratories and damaged other structures and utilities. Initial studies suggested that the liquefaction was a local phenomenon. More detailed offshore investigations, however, indicate that it occurred over a large area (max. 8 km 2 ) during or shortly after the earthquake with movement of unconsolidated sediment toward and into the head of Monterey submarine canyon. This conclusion is supported by side-scan sonographs, high-resolution seismic-reflection and bathymetric profiles, onshore and sea-floor photographs, and underwater video tapes. Many distinct lobate features were identified on the shallow shelf. These features almost certainly were the result of the October 17 earthquake; they were subsequently destroyed by winter storms. In addition, fresh slump scars and recently dislodged mud debris were found on the upper, southern wall of Monterey submarine canyon.

Geology↗
USGS1996

Magnitude and timing of episodic sea-level rise during the last deglaciation

A succession of elevated ridge deposits on the south Florida margin was mapped using high-resolution seismic and side-scan sonar imaging in water depths ranging from 50 to 124 m. The ridges are interpreted to be subtidal shoal complexes and paleoshorelines (eolian dune or beach) formed during the last sea-level transgression. Oolitic and skeletal grainstones and mixed skeletal-peloidal-ooid packstones were recovered using a research submersible. All of the grains are of shallow-water or intertidal origin, and both marine and nonmarine cements were identified.

Geology↗
USGS2009

Prominence of ichnologically influenced macroporosity in the karst Biscayne aquifer: Stratiform "super-K" zones

A combination of cyclostratigraphic, ichnologic, and borehole geophysical analyses of continuous core holes; tracer-test analyses; and lattice Boltzmann flow simulations was used to quantify biogenic macroporosity and permeability of the Biscayne aquifer, southeastern Florida. Biogenic macroporosity largely manifests as: (1) ichnogenic macroporosity primarily related to postdepositional burrowing activity by callianassid shrimp and fossilization of components of their complex burrow systems (Ophiomorpha); and (2) biomoldic macroporosity originating from dissolution of fossil hard parts, principally mollusk shells. Ophiomorpha-dominated ichno-fabric provides the greatest contribution to hydrologic characteristics in the Biscayne aquifer in a 345 km 2 study area. Stratiform tabular-shaped units of thalassinidean-associated macroporosity are commonly confined to the lower part of upward-shallowing high-frequency cycles, throughout aggradational cycles, and, in one case, they stack vertically within the lower part of a high-frequency cycle set. Broad continuity of many of the macroporous units concentrates groundwater flow in extremely permeable passage-ways, thus making the aquifer vulnerable to long-distance transport of contaminants. Ichnogenic macroporosity represents an alternative pathway for concentrated groundwater flow that differs considerably from standard karst flow-system paradigms, which describe groundwater movement through fractures and cavernous dissolution features. Permeabilities were calculated using lattice Boltzmann methods (LBMs) applied to computer renderings assembled from X-ray computed tomography scans of various biogenic macroporous limestone samples. The highest simulated LBM permeabilities were about five orders of magnitude greater than standard laboratory measurements using air-permeability methods, which are limited in their application to extremely permeable macroporous rock samples. Based on their close conformance to analytical solutions for pipe flow, LBMs offer a new means of obtaining accurate permeability values for such materials. We suggest that the stratiform ichnogenic groundwater flow zones have permeabilities even more extreme (???2-5 orders of magnitude higher) than the Jurassic "super-K" zones of the giant Ghawar oil field. The flow zones of the Pleistocene Biscayne aquifer provide examples of ichnogenic macroporosity for comparative analysis of origin and evolution in other carbonate aquifers, as well as petroleum reservoirs. ?? 2008 Geological Society of America.

Geological Society of America Bulletin↗
USGS2003

Evidence for orbitally controlled size variations of the East Antarctic Ice Sheet during the late Miocene

Ocean Drilling Program Site 1165 penetrated drift sediments on the East Antarctic continental rise and recovered sediments from a low-energy depositional environment. The sediments are characterized by prominent alternations between a green to greenish-gray diatom-bearing hemipelagic facies and gray to dark gray hemiturbiditic facies. Our investigation of an upper Miocene section, using high-resolution color spectra, multisensor core logs, and X-ray fluorescence scans, reveals that sedimentation changes occur at Milankovitch orbital frequencies of obliquity and precession. We use this finding to derive an astronomical calibrated time scale and to calculate iron mass-accumulation rates, as a proxy for sediment-accumulation rates. Terrigenous iron fluxes change by as much as 100% during each obliquity cycle. This change and an episodic pattern of enhanced ice-rafted debris deposition during times of deglaciation provide evidence for a dynamic and likely wet-based late Miocene East Antarctic Ice Sheet (EAIS) that underwent large size variations at orbital time scales. The dynamic behavior of the EAIS implies that a significant proportion of the variability seen in oxygen isotope records of the late Miocene reflects Antarctic ice-volume changes.

Geology↗
USGS2008

Trace elements in hydrothermal quartz: Relationships to cathodoluminescent textures and insights into vein formation

High-resolution electron microprobe maps show the distribution of Ti, Al, Ca, K, and Fe among quartz growth zones revealed by scanning electron microscope-cathodoluminescence (SEM-CL) from 12 hydrothermal ore deposits formed between ???100 and e1750 ??C. The maps clearly show the relationships between trace elements and CL intensity in quartz. Among all samples, no single trace element consistently correlates with variations in CL intensity. However in vein quartz from five porphyry-Cu (Mo-Au) deposits, CL intensity always correlates positively with Ti concentrations, suggesting that Ti is a CL activator in quartz formed at >400 ??C. Ti concentrations in most rutile-bearing vein quartz from porphyry copper deposits indicate reasonable formation temperatures of <750 ??C using the TitaniQ geothermometer. Titanium concentrations of <10 ppm in all veins that formed at temperatures <350 ??C suggest broad correlation between Ti concentrations and temperature of quartz precipitation. In quartz from most deposits formed at <350 ??C, bimodal Al concentrations exist wherein some growth bands contain <50 ppm and others contain >2000 ppm, but in high-temperature quartz, Al concentrations are consistently in the range of several hundred ppm. Aluminum concentrations in quartz refl ect the Al solubility in hydrothermal fluids, which is strongly dependent on pH. Aluminum concentrations in quartz therefore reflect fluctuations in pH that may drive metal-sulfide precipitation in hydrothermal systems. ?? 2008 The Geological Society of America.

Geology↗
USGS2011

Pore networks in continental and marine mudstones: Characteristics and controls on sealing behavior

Mudstone pore networks are strong modifiers of sedimentary basin fluid dynamics and have a critical role in the distribution of hydrocarbons and containment of injected fluids. Using core samples from continental and marine mudstones, we investigate properties of pore types and networks from a variety of geologic environments, together with estimates of capillary breakthrough pressures by mercury intrusion porosimetry. Analysis and interpretation of quantitative and qualitative three-dimensional (3D) observations, obtained by dual focused ion beam–scanning electron microscopy, suggest seven dominant mudstone pore types distinguished by geometry and connectivity. A dominant planar pore type occurs in all investigated mudstones and generally has high coordination numbers (i.e., number of neighboring connected pores). Connected networks of pores of this type contribute to high mercury capillary pressures due to small pore throats at the junctions of connected pores and likely control most matrix transport in these mudstones. Other pore types are related to authigenic (e.g., replacement or pore-lining precipitation) clay minerals and pyrite nodules; pores in clay packets adjacent to larger, more competent clastic grains; pores in organic phases; and stylolitic and microfracture-related pores. Pores within regions of authigenic clay minerals often form small isolated networks (<3 μm). Pores in stringers of organic phases occur as tubular pores or slit- and/or sheet-like pores. These form short, connected lengths in 3D reconstructions, but appear to form networks no larger than a few microns in size. Sealing efficiency of the studied mudstones increases with greater distal depositional environments and greater maximum depth of burial.

Geosphere↗
USGS2015

SHRIMP U–Pb and REE data pertaining to the origins of xenotime in Belt Supergroup rocks: evidence for ages of deposition, hydrothermal alteration, and metamorphism

The Belt–Purcell Supergroup, northern Idaho, western Montana, and southern British Columbia, is a thick succession of Mesoproterozoic sedimentary rocks with an age range of about 1470–1400 Ma. Stratigraphic layers within several sedimentary units were sampled to apply the new technique of U–Pb dating of xenotime that sometimes forms as rims on detrital zircon during burial diagenesis; xenotime also can form epitaxial overgrowths on zircon during hydrothermal and metamorphic events. Belt Supergroup units sampled are the Prichard and Revett Formations in the lower Belt, and the McNamara and Garnet Range Formations and Pilcher Quartzite in the upper Belt. Additionally, all samples that yielded xenotime were also processed for detrital zircon to provide maximum age constraints for the time of deposition and information about provenances; the sample of Prichard Formation yielded monazite that was also analyzed. Ten xenotime overgrowths from the Prichard Formation yielded a U–Pb age of 1458 ± 4 Ma. However, because scanning electron microscope – backscattered electrons (SEM–BSE) imagery suggests complications due to possible analysis of multiple age zones, we prefer a slightly older age of 1462 ± 6 Ma derived from the three oldest samples, within error of a previous U–Pb zircon age on the syn-sedimentary Plains sill. We interpret the Prichard xenotime as diagenetic in origin. Monazite from the Prichard Formation, originally thought to be detrital, yielded Cretaceous metamorphic ages. Xenotime from the McNamara and Garnet Range Formations and Pilcher Quartzite formed at about 1160– 1050 Ma, several hundred million years after deposition, and probably also experienced Early Cretaceous growth. These xenotime overgrowths are interpreted as metamorphic–diagenetic in origin (i.e., derived during greenschist facies metamorphism elsewhere in the basin, but deposited in sub-greenschist facies rocks). Several xenotime grains are older detrital grains of igneous derivation. A previous study on the Revett Formation at the Spar Lake Ag–Cu deposit provides data for xenotime overgrowths in several ore zones formed by hydrothermal processes; herein, those results are compared with data from newly analyzed diagenetic, metamorphic, and magmatic xenotime overgrowths. The origin of a xenotime overgrowth is reflected in its rareearth element (REE) pattern. Detrital (i.e., igneous) xenotime has a large negative Eu anomaly and is heavy rare-earth element (HREE)-enriched (similar to REE in igneous zircon). Diagenetic xenotime has a small negative Eu anomaly and flat HREE (Tb to Lu). Hydrothermal xenotime is depleted in light rare-earth element (LREE), has a small negative Eu anomaly, and decreasing HREE. Metamorphic xenotime is very LREE-depleted, has a very small negative Eu anomaly, and is strongly depleted in HREE (from Gd to Lu). Because these characteristics seem to be process related, they may be useful for interpretation of xenotime of unknown origin. The occurrence of 1.16–1.05 Ga metamorphic xenotime, in the apparent absence of pervasive deformation structures, suggests that the heating may be related to poorly understood regional heating due to broad regional underplating of mafic magma. These results may be additional evidence (together with published ages from metamorphic titanite, zircon, monazite, and garnet) for an enigmatic, Grenville-age metamorphic event that is more widely recognized in the southwestern and eastern United States

Alberta, British Columbia, Idaho, Montana, Oregon,↗
USGS2001

Sperm-cell ultrastructure of North American sturgeons. IV. The pallid sturgeon (Scaphirhynchus albus Forbes and Richardson, 1905)

Sperm-cell morphology and ultrastructure in the pallid sturgeon (Scaphirhynchus albus) were examined using transmission and scanning electron microscopy. Metrics and structure were compared with similar metrics obtained from other published descriptions of sturgeon sperm cells. General morphology was found to be similar to that of sperm cells of the white (Acipenser transmontanus), lake (A. fulvescens), stellate (A. stellatus), Chinese (A. sinensis), Russian (A. gueldenstaedti colchicus), and shortnose (A. brevirostrum) sturgeons, which all shared a gradual tapering of the nuclear diameter from posterior to anterior, unlike that of the Atlantic sturgeon (A. oxyrhynchus). The sperm cell of the pallid sturgeon was similar in size to that of the Atlantic sturgeon, being only slightly larger. The sperm cell of the pallid sturgeon differed from those of other sturgeons chiefly in the acrosomal region, where the posterolateral projections (PLP) have the shape of an acute triangle and are arranged in a spiral about the longitudinal axis of the cell. The PLP were longer than those of other sturgeons, being twice the length of those of the Atlantic sturgeon and 58% longer than those of the lake sturgeon. Also, in cross section the acrosome had the shape of a hollow cone rather than the cap of an oak tree acorn, as was found in ultrastructural studies of other sturgeons. In addition, we were able to confirm that the structural arrangement of the distal centriole of the midpiece is identical with that of the proximal centriole: nine sets of microtubular triplets around the periphery of the centriole. This information is of potential use to fishery biologists, forensic biologists, zoologists, reproductive physiologists, taxonomists, evolutionary biologists, and aquaculturists.

Canadian Journal of Zoology↗
USGS1992

Submarine sedimentary features on a fjord delta front, Queen Inlet, Glacier Bay, Alaska

Side-scan sonar images provide a view of an actively changing delta front in a marine outwash fjord in Glacier Bay, Alaska. Numerous interconnected gullies and chute-like small channels form paths for the transport of sand and coarse silt from the braided glacial outwash streams on the delta plain to the sinuous turbidity-current channels incised into the fjord floor. These turbidity-current channels carry coarse sediment through the fjord and into the adjoining glacial trunk valley. Several sedimentary processes affect the development of this delta front: overflow plumes deposit fine sediment; sediment gravity flows result from episodic delivery of large loads of coarse sediment; and mass movement may be triggered by earthquakes and, more regularly, by spring-tidal drawdown or hydraulic loading.

Canadian Journal of Earth Sciences↗
USGS2012

A nearshore processes field experiment at Cape Hatteras, North Carolina, U.S.A.

A month-long field experiment focused on the nearshore hydrodynamics of Diamond Shoals adjacent to Cape Hatteras Point, North Carolina, was conducted in February 2010. The objectives of this multi-institutional experiment were to test hypotheses related to Diamond Shoals as a sink in the regional sediment budget and to provide data for evaluating numerical models. The experiment included in-situ instrumentation for measuring waves and currents; a video camera system for measuring surface currents at a nearshore transect; a radar system for measuring regional surface currents over Diamond Shoals and the adjacent coast; a vehicle-based scanning lidar and radar system for mapping beach topography, nearshore wave breaking intensity, bathymetry (through wave celerity inversion), and wave direction; and an amphibious vehicle system for surveying single-beam bathymetry. Preliminary results from wave and current measurements suggest that shoal-building processes were active during the experiment.

North Carolina↗
USGS2025

Evaluating sediment transport and metal sorption in the San Juan River watershed

The physical and chemical characteristics of sediment influence the transport of metals in rivers. The San Juan River and its tributaries are located in the Four Corners Region in the southwestern United States and the watershed contains a wide variety of potential metal sources. Comparisons of past and present sediment data provide insight into the effects of seasonality and storm events on the transport of sediment within a watershed. Comparisons suggest finer (<0.63 µm) sediment particles increase at a greater rate during intense storm events than coarser sediment particles. These fine, clay-sized sediments have a greater potential for metal sorption. Statistical analyses compared upper and lower portions of the San Juan River. Results show that total elemental concentration decreases in sediments (1785.15 μ g l −1 ) and that concentrations increase in the aqueous phase (2063.08 μ g l −1 ) downstream in the San Juan River. Analyses using geochemical and scanning electron microscopy with energy dispersive spectroscopy suggest that sediment clay particles are the most likely constituent to transport metals in the San Juan River. Metal transport is further aided by metal oxide coatings that develop on the surfaces of larger particles. Increases in aggregation of fine-grained particles in the downstream portions of the San Juan River are also likely to bind elements within sediments, which can act as both a source and sink for metals in the lower watershed. CEC , geochemistry , PSD

Arizona, Colorado, New Mexico, Utah↗
USGS2016

Submarine glacial landforms on the Bay of Fundy–northern Gulf of Maine continental shelf

The Bay of Fundy–northern Gulf of Maine region surrounds the southern part of Nova Scotia, encompassing, from west to east, the Bay of Fundy, Grand Manan Basin, German Bank, Browns Bank, Northeast Channel and northeastern Georges Bank (Fig. 1a, b). During the last glacial maximum ( c. 24–20 14 C ka BP), the SE margin of the Laurentide Ice Sheet (LIS) occupied the study area, the rest of the Gulf of Maine and the continental Scotian Shelf off Atlantic Canada (see Dyke et al. 2002 , fig. 1; Shaw et al. 2006 , fig. 8; Hundert & Piper 2008 , fig. 16). Early mapping of the glaciated region on the Scotian Shelf using side-scan sonar imagery and seismic-reflection profiles revealed topographic features interpreted to be recessional moraines indicative of retreat of the LIS ( King et al. 1972 ; King 1996 ). Subsequently, multibeam sonar seafloor mapping of local-scale glacial landforms on the inner Scotian Shelf off Halifax, Nova Scotia (Fig. 1b) provided further information on the dynamics of the advance and retreat of the ice sheet ( Loncarevic et al. 1994 ). Interpretation of seismic-reflection profiles across Georges Bank revealed that the surficial sediment is a veneer of glacial debris transported to Georges Bank by the LIS during the late Pleistocene from continental areas to the north ( Shepard et al. 1934 ; Knott & Hoskins 1968 ; Schlee 1973 ; Twichell et al. 1987 ; Fader et al. 1988 ). Recent high-resolution multibeam sonar surveys of German Bank and the Bay of Fundy mapped a complex of ice-advance and ice-retreat features attributed to the activity of the LIS ( Todd et al. 2007 ; Todd & Shaw 2012 ).

Geological Society, London, Memoirs↗
USGS2017

The application of microtextural and heavy mineral analysis to discriminate between storm and tsunami deposits

Recent work has applied microtextural and heavy mineral analyses to sandy storm and tsunami deposits from Portugal, Scotland, Indonesia and the USA. We looked at the interpretation of microtextural imagery (scanning electron microscopy) of quartz grains and heavy mineral compositions. We consider inundation events of different chronologies and sources (the AD 1755 Lisbon and 2004 Indian Ocean tsunamis, the Great Storm of 11 January 2005 in Scotland, and Hurricane Sandy in 2012) that affected contrasting coastal and hinterland settings with different regional oceanographic conditions. Storm and tsunami deposits were examined along with potential source sediments (alluvial, beach, dune and nearshore sediments) to determine provenance. Results suggest that tsunami deposits typically exhibit a significant spatial variation in grain sizes, microtextures and heavy minerals. Storm deposits show less variability, especially in vertical profiles. Tsunami and storm quartz grains had more percussion marks and fresh surfaces compared to potential source material. Moreover, in the studied cases, tsunami samples had fewer fresh surfaces than storm deposits. Heavy mineral assemblages are typically site-specific. The concentration of heavy minerals decreases upwards in tsunamigenic units, whereas storm sediments show cyclic concentrations of heavy minerals, reflected in the laminations observed macroscopically in the deposits.

Geological Society, London, Special Publications↗
USGS1995

Evidence from tooth surface morphology for a posterior maxillary origin of the proteroglyph fang

Although the front-fanged venom delivery system of the Elapidae is believed to be derived from an aglyphous or opisthoglyphous colubroid ancestor, opinion is divided as to the end of the maxilla on which the proteroglyph fang originated. This study was undertaken to determine whether the evolutionary precursor of the proteroglyph fang was (a) a grooved posterior fang which migrated anteriorly, or (b) an enlarged anterior tooth which secondarily developed a groove for the conduction of venom. The surface morphology of the maxillary teeth of colubrid genera was examined using scanning electron microscopy. Ridges present on the lingual and labial surfaces of anterior maxillary teeth and on the anterior and posterior surfaces of posterior maxillary teeth were identified as morphological markers of potential value in distinguishing the anterior and posterior maxillary teeth of colubrid snakes, and in determining the origin of the proteroglyph fang. Patterns of ridges on the surfaces of elapid fangs examined were found to be consistent with the hypothesis that the evolutionary precursor of the proteroglyph fang was an opisthoglyph fang which migrated anteriorly.

Amphibia-Reptilia↗
USGS2022

Demonstration of a novel quantitative microscopy technique for automated characterization of in situ particulate matter in coal miners with progressive massive fibrosis

Rationale: Increasing exposure to respirable crystalline silica (RCS) linked to changes in mining production processes has been implicated in the resurgence of severe lung disease in U.S. coal miners. Lung mineralogy can provide insight into particle pathogenesis. However, standard approaches to characterizing in situ particulate matter (PM) by pulmonary pathologists have poor inter-rater comparability, and consensus agreement is time consuming. Scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDX) is technically complex and labor intensive. We developed a method for quantitative in situ PM characterization using conventional polarized light microscopy (PLM) and explored PM features in lung tissue of coal miners with progressive massive fibrosis (PMF). Methods: With institutional review board approval, PLM images were obtained from 30 miners with PMF, classified by pathologists consensus based on PM profusion; 10 from each profusion group (mild/moderate/severe) were selected. Automated PM counting and characterization (including dimensions and grayscale intensity of PM > 0.3 m diameter) was performed on image samples using PLM with modified cell-counting software (BZ-X800 light microscope, Keyence Corporation, Osaka, Japan) (Figure 1). Quantitative PM density loge(PM count)/mm3 tissue was calculated for each sample and compared to pathologist PM profusion groups. PMF lesion type using consensus pathologist classification (13 coal-type, 9 mixed-type, and 8 silicotic-type) was compared to automated PM birefringence level (% particles with mean grayscale intensity <65, range 0-255). RCS particles are expected to be weakly birefringent (lower intensity) relative to other common minerals (e.g., silicates) contained in coal mine dust. PM features were analyzed in R 4.0.3 using one-way ANOVA for between-group comparisons. Results: Measured PM log-density increased significantly with higher qualitative profusion group (mild=10.480.98/mm3, moderate=11.460.81/mm3, severe=12.520.86/mm3, p<0.0001). Prevalence of weakly birefringent particles was significantly higher among silicotic-type PMF samples (31.57.9%) compared to either coal-type (21.510.1%, p=0.022) or mixed-type lesions (21.510.5%, p=0.025). Conclusion: This pilot study demonstrates the feasibility of a novel quantitative microscopy technique for counting and characterizing in situ lung PM in coal miners with PMF. Quantitative PM burden was comparable to pulmonary pathologists consensus profusion classification, but this method was substantially less time consuming and labor intensive and provided additional information about relevant PM features. The higher prevalence of weakly birefringent particles seen in silicotic-type PMF lesions may help inform mineralogic pathogenesis of RCS. Future efforts will expand the number of PMF cases analyzed, further validate our mineralogic findings using data from SEM/EDX and lung tissue digestate methods, and compare findings in historical versus contemporary coal miners with PMF.

Conference Paper↗
USGS2013

Three new Psammothidium species from lakes of Olympic and Cascade Mountains in Washington State, USA

Populations of several Psammothidium species were found in core sediments from nine remote, high elevation, ultraoligotrophic and oligotrophic, Olympic and Cascade Mountain lakes. Three of these species, P. lacustre, P. alpinum , and P. nivale , are described here as new. The morphology of the silica frustules of these species was documented using light and scanning electron microscopy. We discuss the similarities and differences with previously described Psammothidium species.

Washington↗
USGS2009

Numerical simulations and observations of surface wave fields under an extreme tropical cyclone

The performance of the wave model WAVEWATCH III under a very strong, category 5, tropical cyclone wind forcing is investigated with different drag coefficient parameterizations and ocean current inputs. The model results are compared with field observations of the surface wave spectra from an airborne scanning radar altimeter, National Data Buoy Center (NDBC) time series, and satellite altimeter measurements in Hurricane Ivan (2004). The results suggest that the model with the original drag coefficient parameterization tends to overestimate the significant wave height and the dominant wavelength and produces a wave spectrum with narrower directional spreading. When an improved drag parameterization is introduced and the wave-current interaction is included, the model yields an improved forecast of significant wave height, but underestimates the dominant wavelength. When the hurricane moves over a preexisting mesoscale ocean feature, such as the Loop Current in the Gulf of Mexico or a warm-and cold-core ring, the current associated with the feature can accelerate or decelerate the wave propagation and significantly modulate the wave spectrum. ?? 2009 American Meteorological Society.

Journal of Physical Oceanography↗
USGS2012

Partly cloudy with a chance of migration: Weather, radars, and aeroecology

Aeroecology is an emerging scientific discipline that integrates atmospheric science, Earth science, geography, ecology, computer science, computational biology, and engineering to further the understanding of biological patterns and processes. The unifying concept underlying this new transdisciplinary field of study is a focus on the planetary boundary layer and lower free atmosphere (i.e., the aerosphere), and the diversity of airborne organisms that inhabit and depend on the aerosphere for their existence. Here, we focus on the role of radars and radar networks in aeroecological studies. Radar systems scanning the atmosphere are primarily used to monitor weather conditions and track the location and movements of aircraft. However, radar echoes regularly contain signals from other sources, such as airborne birds, bats, and arthropods. We briefly discuss how radar observations can be and have been used to study a variety of airborne organisms and examine some of the many potential benefits likely to arise from radar aeroecology for meteorological and biological research over a wide range of spatial and temporal scales. Radar systems are becoming increasingly sophisticated with the advent of innovative signal processing and dual-polarimetric capabilities. These capabilities should be better harnessed to promote both meteorological and aeroecological research and to explore the interface between these two broad disciplines. We strongly encourage close collaboration among meteorologists, radar scientists, biologists, and others toward developing radar products that will contribute to a better understanding of airborne fauna.

Bulletin of the American Meteorological Society↗