Now showing items 5661-5680 of 14016

    • Inter-Calibration of the OSIRIS-REx NavCams with Earth-Viewing Imagers

      Doelling, David; Khlopenkov, Konstantin; Haney, Conor; Bhatt, Rajendra; Bos, Brent; Scarino, Benjamin; Gopalan, Arun; Lauretta, Dante S.; Univ Arizona, Lunar & Planetary Lab (MDPI, 2019-11-19)
      The Earth-viewed images acquired by the space probe OSIRIS-REx during its Earth gravity assist flyby maneuver on 22 September 2017 provided an opportunity to radiometrically calibrate the onboard NavCam imagers. Spatially-, temporally-, and angularly-matched radiances from the Earth viewing GOES-15 and DSCOVR-EPIC imagers were used as references for deriving the calibration gain of the NavCam sensors. An optimized all-sky tropical ocean ray-matching (ATO-RM) calibration approach that accounts for the spectral band differences, navigation errors, and angular geometry differences between NavCam and the reference imagers is formulated in this paper. Prior to ray-matching, the GOES-15 and EPIC pixel level radiances were mapped into the NavCam field of view. The NavCam 1 ATO-RM gain is found to be 9.874 x 10(-2) Wm(-2)sr(-1)mu m(-1)DN(-1) with an uncertainty of 3.7%. The ATO-RM approach predicted an offset of 164, which is close to the true space DN of 170. The pre-launch NavCam 1 and 2 gains were compared with the ATO-RM gain and were found to be within 2.1% and 2.8%, respectively, suggesting that sensor performance is stable in space. The ATO-RM calibration was found to be consistent within 3.9% over a factor of +/- 2 NavCam 2 exposure times. This approach can easily be adapted to inter-calibrate other space probe cameras given the current constellation of geostationary imagers.
    • Inter-loop optimizations in RAJA using loop chains

      Neth, B.; Scogland, T.R.W.; de Supinski, B.R.; Strout, M.M.; University of Arizona (Association for Computing Machinery, 2021-06)
      Typical parallelization approaches such as OpenMP and CUDA provide constructs for parallelizing and blocking for data locality for individual loops. By focusing on each loop separately, these approaches fail to leverage sources of data locality possible due to inter-loop data reuse. The loop chain abstraction provides a framework for reasoning about and applying inter-loop optimizations. In this work, we incorporate the loop chain abstraction into RAJA, a performance portability layer for high-performance computing applications. Using the loop-chain-extended RAJA, or RAJALC, developers can have the RAJA library apply loop transformations like loop fusion and overlapped tiling while maintaining the original structure of their programs. By introducing targeted symbolic evaluation capabilities, we can collect and cache data access information required to verify loop transformations. We evaluate the performance improvement and refactoring costs of our extension. Overall, our results demonstrate 85-98% of the performance improvements of hand-optimized kernels with dramatically fewer code changes. © 2021 Association for Computing Machinery.
    • Inter-organizational dynamics and the ecology of localized entrepreneurship

      Mars, Matthew M.; Univ Arizona, Dept Agr Educ Technol & Innovat (Informa UK Limited, 2020-01-30)
      In this paper, a set of ecological principles (actor-type, interaction-type, nestedness) that have been theoretically associated with organizational ecosystems guides a qualitative exploration of the ecology of localized entrepreneurial clusters (LECs). The focus of analysis is the Southern Arizona craft brewing sector (SACBS). The inter-organizational dynamic that characterizes the ecology of the SACBS is found to be based more on mutualism than on competition. This dynamic is primarily based on shared commitments to local beer brand identity, product quality, and sustainable production, as well as an overall sense of community connectedness. The SACBS is also shown to be a tightly nested LEC with craft breweries operating primarily as generalists within the local context rather than as specialists within the national and global contexts. Findings illustrate the strategic value of treating LECs as community-based sectors that are driven more by inter-organizational coordination and collaboration than by division and competition.
    • Interaction Among Magmas from Various Sources and Crustal Melting Processes During Continental Collision: Insights from the Huayang Intrusive Complex of the South Qinling Belt, China

      Hu, Fangyang; Liu, Shuwen; Ducea, Mihai N; Zhang, Wanyi; Chapman, James B; Fu, Jinghao; Wang, Maojiang; Univ Arizona, Dept Geosci (OXFORD UNIV PRESS, 2018-04)
      The Qinling Orogenic Belt in central China, which resulted from continent-continent collision, is an excellent area for the study of collision-related magmatism. An integrated study including detailed field investigations, petrography, mineral and whole-rock geochemistry, zircon U-Pb-Hf-O isotopes, and geochemical modeling was carried out on the Huayang intrusive complex-a key magmatic intrusion in the South Qinling Belt-in order to understand the nature and melt source regions of magmatism associated with continental collisional orogenesis. The Huayang intrusive complex is composed of similar to 207-202 Ma medium to fine-grained granite, coarse to medium-grained granite of the same age, similar to 214-207 Ma tonalite and granodiorite, and rare similar to 218-213 Ma mafic xenoliths. The mafic xenoliths are characterized by enriched large ion lithophile elements, with zircon eHf(t) values of -6.8 to+4.1 and average zircon delta O-18 of 6.1 parts per thousand, which suggests that the xenoliths may represent melts derived from phlogopite-bearing lithospheric mantle. The tonalites and granodiorites exhibit high Sr/Y and La/Yb, but low Rb/Sr, with variable zircon eHf(t) values of - 6.7 to +1..9 and zircon delta O-18 values of 5.3 parts per thousand to 9.0 parts per thousand. We suggest that they were derived from partial melting of Neoproterozoic, low delta O-18 basaltic rocks with a minor input of mafic magma. These melts underwent fractional crystallization and assimilated high delta O-18 crustal materials during magma ascent and emplacement. The coarse to medium-grained granitic rocks have zircon epsilon Hf(t) values of -7.3 to +1.5, with low zircon delta O-18 values (average 5.7 parts per thousand). The medium to fine-grained granitic rocks have zircon eHf(t) values of -14.7 to +1.1, with high zircon delta O-18 values (average 8.4 parts per thousand). Both of these granitic rock types show similar whole-rock geochemistry, with metaluminous to strongly peraluminous compositions, and are characterized by intermediate to low Sr/Y values. We propose that the coarse to medium-grained granites originated from partial melting of low delta O-18 Neoproterozoic metabasaltic to metatonalitic rocks, and that the medium to fine-grained granites were derived from high delta O-18 Neoproterozoic metagreywackes. Both granitic magma types experienced plagioclase-dominated fractional crystallization during magma ascent and emplacement. The data suggest that three different source materials were involved in magmatism in the South Qinling Belt: 1) the lithospheric mantle; 2) low delta O-18 Neoproterozoic metabasaltic to tonalitic rocks, and 3) high delta O-18 Neoproterozoic metagreywackes. Slab break-off and/or dehydration of the subducted slab may have induced the melting of the sub-continental lithospheric mantle and caused subsequent crustal melting by heating the base of the crust. The results of this study suggest that magmatism in continental collisional orogens is not only generated by heating from radioactive element decay during crustal thickening.
    • The Interaction between Dietary Fiber and Fat and Risk of Colorectal Cancer in the Women’s Health Initiative

      Navarro, Sandi; Neuhouser, Marian; Cheng, Ting-Yuan; Tinker, Lesley; Shikany, James; Snetselaar, Linda; Martinez, Jessica; Kato, Ikuko; Beresford, Shirley; Chapkin, Robert; et al. (MDPI AG, 2016-11-30)
      Combined intakes of specific dietary fiber and fat subtypes protect against colon cancer in animal models. We evaluated associations between self-reported individual and combinations of fiber (insoluble, soluble, and pectins, specifically) and fat (omega-6, omega-3, and docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), specifically) and colorectal cancer (CRC) risk in the Women's Health Initiative prospective cohort (n = 134,017). During a mean 11.7 years (1993-2010), 1952 incident CRC cases were identified. Cox regression models computed multivariate adjusted hazard ratios to estimate the association between dietary factors and CRC risk. Assessing fiber and fat individually, there was a modest trend for lower CRC risk with increasing intakes of total and insoluble fiber (p-trend 0.09 and 0.08). An interaction (p = 0.01) was observed between soluble fiber and DHA + EPA, with protective effects of DHA + EPA with lower intakes of soluble fiber and an attenuation at higher intakes, however this association was no longer significant after correction for multiple testing. These results suggest a modest protective effect of higher fiber intake on CRC risk, but not in combination with dietary fat subtypes. Given the robust results in preclinical models and mixed results in observational studies, controlled dietary interventions with standardized intakes are needed to better understand the interaction of specific fat and fiber subtypes on colon biology and ultimately CRC susceptibility in humans.
    • Interaction effect of the mediterranean diet and an obesity genetic risk score on adiposity and metabolic syndrome in adolescents: The HELENA study

      Seral-Cortes, M.; Sabroso-Lasa, S.; De, Miguel-Etayo, P.; Gonzalez-Gross, M.; Gesteiro, E.; Molina-Hidalgo, C.; De, Henauw, S.; Erhardt, É.; Censi, L.; Manios, Y.; et al. (MDPI AG, 2020)
      Obesity and metabolic syndrome (MetS) are worldwide major health challenges. The Mediterranean diet (MD) is associated with a better cardiometabolic profile, but these beneficial effects may be influenced by genetic variations, modulating the predisposition to obesity or MetS. The aim was to assess whether interaction effects occur between an obesity genetic risk score (obesity-GRS) and the MD on adiposity and MetS in European adolescents. Multiple linear regression models were used to assess the interaction effects of an obesity-GRS and the MD on adiposity and MetS and its components. Interaction effects between the MD on adiposity and MetS were observed in both sex groups (p < 0.05). However, those interaction effects were only expressed in a certain number of adolescents, when a limited number of risk alleles were present. Regarding adiposity, a total of 51.1% males and 98.7% females had lower body mass index (BMI) as a result of higher MD adherence. Concerning MetS, only 9.9% of males with higher MD adherence had lower MetS scores. However, the same effect was observed in 95.2% of females. In conclusion, obesity-related genotypes could modulate the relationship between MD adherence and adiposity and MetS in European adolescents; the interaction effect was higher in females than in males. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
    • Interaction effects of nitrogen and phosphorus fertilizer on nitrogen mineralization of wheat residues in a calcareous soil

      Akbari, Farideh; Fallah, Sina; Dahmardeh, Mehdi; Pessarakli, Mohammad; Univ Arizona, Honors Coll, Sch Plant Sci; Univ Arizona, Honors Coll, Adjunct Fac (TAYLOR & FRANCIS INC, 2019-09-13)
      Because of the high pH of the soil in semiarid regions, phosphorus adsorption is unfavorable. So, considerable amounts of phosphorus fertilizers are used annually, where this fertilizer may affect the plant residues' decomposition. To examine the interaction effects of nitrogen and phosphorus on nitrogen mineralization in calcareous soil, a factorial experiment was performed in a completely randomized design with three replications. The first factor consisted of various C:N ratios (20, 40, and 60 or three levels of nitrogen N-1:0, N-2:11, and N-3:43 kg N ha(-1), respectively) and the second factor consisted of various C:P ratios (87, 174, and 260 or three levels of phosphorus P-1:0, P-2:12, and P-3:45 kg P ha(-1), respectively), under incubation conditions. The results indicated that the cumulative mineral nitrogen content in all treatments, except for N1P2 and N1P3 treatments, started from a positive amount and remained positive until the end of the incubation period. The highest amount of cumulative mineral nitrogen among treatments was related to N3P1 treatment, while the lowest was associated with N2P3 treatment. Mineralization of nitrogen during 60 d of incubation was the dominant phenomenon, except for the N1P2 and N1P3 treatments which remained in the organic phase. The effect of phosphorus on the cumulative mineralization of nitrogen was significant. With increasing the amount of phosphorus, the total inorganic nitrogen diminished. Nitrogen release begins earlier with lower C:N ratios, and therefore the available nitrogen can be released more quickly to the plant. It is generally concluded that, in calcareous soil, the use of nitrogen fertilizer to adjust C:N ratio and to improve the mineralization of wheat residues will be a suitable option.
    • Interaction of Age and Self-reported Physical Sports Activity on White Matter Hyperintensity Volume in Healthy Older Adults

      Franchetti, Mary Kathryn; Bharadwaj, Pradyumna K; Nguyen, Lauren A; Van Etten, Emily J; Klimentidis, Yann C; Hishaw, Georg A; Trouard, Theodore P; Raichlen, David A; Alexander, Gene E; Univ Arizona, Dept Psychol; et al. (FRONTIERS MEDIA SA, 2020-11-02)
      Cerebral white matter (WM) lesion load, as measured by white matter hyperintensity (WMH) volume with magnetic resonance imaging (MRI), has been associated with increasing age and cardiovascular risk factors, like hypertension. Physical sports activity (PSA) may play an important role in maintaining WM in the context of healthy aging. In 196 healthy older adults, we investigated whether participants reporting high levels of PSA (n = 36) had reduced total and regional WMH volumes compared to those reporting low levels of PSA (n = 160). Age group [young-old (YO) = 50-69 years; old-old (OO) = 70-89 years], PSA group, and age by PSA group interaction effects were tested, with sex, hypertension, and body mass index (BMI) as covariates. We found significant main effects for age group and age by PSA group interactions for total, frontal, temporal, and parietal WMH volumes. There were no main effects of PSA group on WMH volumes. The OO group with low PSA had greater total, frontal, temporal, and parietal WMH volumes than the YO with low PSA and OO with high PSA groups. WMH volumes for the YO and OO groups with high PSA were comparable. These findings indicate an age group difference in those with low PSA, with greater WMH volumes in older adults, which was not observed in those with high PSA. The results suggest that engaging in high levels of PSA may be an important lifestyle factor that can help to diminish WMH lesion load in old age, potentially reducing the impact of brain aging.
    • Interaction rewiring and the rapid turnover of plant-pollinator networks

      CaraDonna, Paul J.; Petry, William K.; Brennan, Ross M.; Cunningham, James L.; Bronstein, Judith L.; Waser, Nickolas M.; Sanders, Nathan J.; Department of Ecology & Evolutionary Biology, University of Arizona; The Rocky Mountain Biological Laboratory; Crested Butte CO 81224 USA; The Rocky Mountain Biological Laboratory; Crested Butte CO 81224 USA; et al. (WILEY-BLACKWELL, 2017-03)
      Whether species interactions are static or change over time has wide-reaching ecological and evolutionary consequences. However, species interaction networks are typically constructed from temporally aggregated interaction data, thereby implicitly assuming that interactions are fixed. This approach has advanced our understanding of communities, but it obscures the timescale at which interactions form (or dissolve) and the drivers and consequences of such dynamics. We address this knowledge gap by quantifying the within-season turnover of plant-pollinator interactions from weekly censuses across 3years in a subalpine ecosystem. Week-to-week turnover of interactions (1) was high, (2) followed a consistent seasonal progression in all years of study and (3) was dominated by interaction rewiring (the reassembly of interactions among species). Simulation models revealed that species' phenologies and relative abundances constrained both total interaction turnover and rewiring. Our findings reveal the diversity of species interactions that may be missed when the temporal dynamics of networks are ignored.
    • An Interaction Ritual Theory of Social Resource Exchange: Evidence from a Silicon Valley Accelerator

      Krishnan, Rekha; Cook, Karen S.; Kozhikode, Rajiv Krishnan; Schilke, Oliver; University of Arizona (SAGE Publications, 2020-11-27)
      Recent research on start-up accelerators has drawn attention to the central importance of social resource exchange among peers for entrepreneurial success. But such peer relationships contain both cooperative and competitive elements, making accelerators a prime example of a mixed-motive context in which successful generalized exchange—unilateral giving without expectations of direct reciprocity—is not a given. In our ethnographic study of a Silicon Valley accelerator, we sought to explore how generalized exchange emerges and evolves over time. Employing an abductive, sequential mixed-methods approach, we develop a process model that helps explain how a system of generalized exchange may or may not emerge. At the core of this model are the interaction rituals within social events that come to create distinct exchange expectations, which are either aligned or incompatible with generalized exchange, resulting in fulfilled or failed exchanges in subsequent encounters. Whereas fulfilled exchanges can kickstart virtuous exchange dynamics and a thriving generalized exchange system, failed exchanges trigger vicious exchange dynamics and an unstable social order. These findings bring clarity to the puzzle of how some generalized exchange systems overcome the social dilemma in mixed-motive contexts by highlighting the central role of alignment between structure and process. © The Author(s) 2020.
    • Interactional Digital Libraries: introduction to a special issue on Interactivity in Digital Libraries

      Coleman, Anita Sundaram; Oxnam, Maliaca; McKnigh, Cliff; Ashman, Helen; Coleman, Anita; Dillon, Andrew; Hall, Wendy; Koch, Traugott; Leggett, John; Lowe, David; et al. (IAM Research Group, 2002-05)
      Advances in Internet technologies have made it seemingly possible and easy to create digital collections, repositories and libraries. However, supporting diverse information uses that facilitate interaction beyond searching and browsing is in the early stages. Interactive digital libraries, or interactional digital libraries as we prefer to call them, are still evolving. This special issue tries to bring together work that is being done to incorporate interactivity in digital libraries.
    • Interactions among interactions: The dynamical consequences of antagonism between mutualists

      Yule, Kelsey M; Johnson, Christopher A; Bronstein, Judith L; Ferrière, Régis; Univ Arizona, Dept Ecol & Evolutionary Biol; Univ Arizona, Paris Sci & Lettres Univ, Int Res Lab Interdisciplinary Global Environm Stu (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2020-05-31)
      Species often interact with multiple mutualistic partners that provide functionally different benefits and/or that interact with different life-history stages. These functionally different partners, however, may also interact directly with one another in other ways, indirectly altering net outcomes and persistence of the mutualistic system as a whole. We present a population dynamical model of a three-species system involving antagonism between species sharing a mutualist partner species with two explicit life stages. We find that, regardless of whether the antagonism is predatory or non-consumptive, persistence of the shared mutualist is possible only under a restrictive set of conditions. As the rate of antagonism between the species sharing the mutualist increases, indirect rather than direct interactions increasingly determine species' densities and sometimes result in complex, oscillatory dynamics for all species. Surprisingly, persistence of the mutualistic system is particularly dependent upon the degree to which each of the two mutualistic interactions is specialized. Our work investigates a novel mechanism by which changing ecological conditions can lead to extinction of mutualist partners and provides testable predictions regarding the interactive roles of mutualism and antagonism in net outcomes for species' densities. (C) 2020 Elsevier Ltd. All rights reserved.
    • Interactions between complex craters and the lunar crust: Analysis using GRAIL data

      Bierson, C. J.; Phillips, Roger J.; Nimmo, Francis; Besserer, Jonathan; Milbury, Colleen; Keane, James T.; Soderblom, Jason M.; Zuber, Maria T.; Univ Arizona, Lunar & Planetary Lab; Department of Earth and Planetary Sciences; University of California; Santa Cruz California USA; et al. (AMER GEOPHYSICAL UNION, 2016-08)
      A high-resolution gravity map over the entire lunar surface has been derived from data acquired by the Gravity Recovery and Interior Laboratory (GRAIL) mission. Soderblom et al. (2015) showed that crater Bouguer gravity anomalies scale with crater diameter and porosity for craters in the lunar highlands. Here we extend this study globally, examining complex craters in each of the three lunar terranes: highlands, maria, and the South Pole-Aitken basin. We find that craters within South Pole-Aitken basin and in the lunar maria have statistically different Bouguer anomalies from those in the lunar highlands. These differences are best explained by differences in crustal porosity among the three terranes. Though there is still much unresolved scatter in the data, we find that no other lunar material properties (crustal thickness, density gradient, etc.) are able to improve our model fit to the data.
    • Interactions between microbial diversity and substrate chemistry determine the fate of carbon in soil

      Raczka, N.C.; Piñeiro, J.; Tfaily, M.M.; Chu, R.K.; Lipton, M.S.; Pasa-Tolic, L.; Morrissey, E.; Brzostek, E.; Department of Environmental Science, University of Arizona (Nature Research, 2021)
      Microbial decomposition drives the transformation of plant-derived substrates into microbial products that form stable soil organic matter (SOM). Recent theories have posited that decomposition depends on an interaction between SOM chemistry with microbial diversity and resulting function (e.g., enzymatic capabilities, growth rates). Here, we explicitly test these theories by coupling quantitative stable isotope probing and metabolomics to track the fate of 13C enriched substrates that vary in chemical composition as they are assimilated by microbes and transformed into new metabolic products in soil. We found that differences in forest nutrient economies (e.g., nutrient cycling, microbial competition) led to arbuscular mycorrhizal (AM) soils harboring greater diversity of fungi and bacteria than ectomycorrhizal (ECM) soils. When incubated with 13C enriched substrates, substrate type drove shifts in which species were active decomposers and the abundance of metabolic products that were reduced or saturated in the highly diverse AM soils. The decomposition pathways were more static in the less diverse, ECM soil. Importantly, the majority of these shifts were driven by taxa only present in the AM soil suggesting a strong link between microbial identity and their ability to decompose and assimilate substrates. Collectively, these results highlight an important interaction between ecosystem-level processes and microbial diversity; whereby the identity and function of active decomposers impacts the composition of decomposition products that can form stable SOM. © 2021, The Author(s).
    • Interannual and Decadal Variability in Tropical Pacific Sea Level

      Peyser, Cheryl; Yin, Jianjun; Univ Arizona, Dept Geosci (MDPI AG, 2017-06-05)
      A notable feature in the first 20-year satellite altimetry records is an anomalously fast sea level rise (SLR) in the western Pacific impacting island nations in this region. This observed trend is due to a combination of internal variability and external forcing. The dominant mode of dynamic sea level (DSL) variability in the tropical Pacific presents as an east-west see-saw pattern. To assess model skill in simulating this variability mode, we compare 38 Coupled Model Intercomparison Project Phase 5 (CMIP5) models with 23-year satellite data, 55-year reanalysis products, and 60-year sea level reconstruction. We find that models underestimate variance in the Pacific sea level see-saw, especially at decadal, and longer, time scales. The interannual underestimation is likely due to a relatively low variability in the tropical zonal wind stress. Decadal sea level variability may be influenced by additional factors, such as wind stress at higher latitudes, subtropical gyre position and strength, and eddy heat transport. The interannual variability of the Nino 3.4 index is better represented in CMIP5 models despite low tropical Pacific wind stress variability. However, as with sea level, variability in the Nino 3.4 index is underestimated on decadal time scales. Our results show that DSL should be considered, in addition to sea surface temperature (SST), when evaluating model performance in capturing Pacific variability, as it is directly related to heat content in the ocean column.
    • Interannual Variation in Diet, Dietary Diversity, and Dietary Overlap in Three Sympatric Strepsirrhine Species in Southeastern Madagascar

      Erhart, E. M.; Tecot, S. R.; Grassi, C.; Univ Arizona, Sch Anthropol (SPRINGER, 2018-04)
      Dietary data are used to categorize species diets, but these categorizations do not take into account the mutability of food resources in time or space, the level of interspecific competition in various communities as these resources change, nor the dietary flexibility of species. In this study, we assess the diets of three sympatric species, Eulemur rufifrons, Propithecus edwardsi, and Varecia variegata, in the Vatoharanana site in Ranomafana National Park, Madagascar. We determine dietary diversity, overlap, and interannual variation with data collected from 2001 to 2003. We then compare results on food preference and time feeding with data collected on each species in the late 1980s and early 1990s to determine whether these findings are consistent over the long term. We found little interannual variation in the proportion of time spent eating particular plant parts for each of the lemur species during the three study years (2001-2003), and between the earlier and current study. Food items were not always consumed based solely on availability. Dietary diversity was lower in the two frugivorous species (V. variegata and E. rufifrons) compared with the folivorous species (P. edwardsi), and V. variegata and E. rufifrons were more likely to focus their feeding time on one particular genus and plant part in each year. The study species used different strategies to deal with food, particularly fruit, shortages such as a plastic social structure (V. variegata), habitat shifting (E. rufifrons), and dietary switching (P. edwardsi). Although there was low dietary overlap between the study species, they depended on a small number of shared fruits in each of the study years (Chrysophyllum, Syzygium, Ocotea, Plagioscyphus), which may indicate some potential for interspecific competition. Because these lemur species, like all primates, lead relatively long lives (avg. > 30 years) and have slow rates of aging, longitudinal studies are needed to test hypotheses reliant on basic dietary information.
    • Interannual Variations of Total Ozone at Northern Midlatitudes Correlated with Stratospheric EP Flux and Potential Vorticity

      Hood, L. L.; Soukharev, B. E.; Univ Arizona, Lunar & Planetary Lab (AMER METEOROLOGICAL SOC, 2005-10)
      At northern midlatitudes over the 1979–2002 time period, column ozone trends are observed to have maximum negative amplitudes in February and March. Here, the portion of the observed ozone interannual variability and trends during these months that can be attributed to two specific dynamical transport processes is estimated using correlative and regression methods. In approximate agreement with a recent independent study, 18%–25% of the observed maximum negative trend is estimated to be due to long-term changes in the diabatic (Brewer–Dobson) circulation driven by global-scale changes in planetary wave [Eliassen–Palm (EP) flux] forcing. In addition, 27%–31% of the observed maximum midlatitude trend during these months is estimated to be due to long-term changes in local nonlinear synoptic wave forcing as deduced from correlated interannual variations of zonal mean ozone and Ertel’s potential vorticity. Like long-term decreases in the Brewer–Dobson circulation, this trend component reflects an overall net increase in the polar vortex strength, which is associated with increased numbers of anticyclonic, poleward-breaking Rossby waves at northern midlatitudes. Together, these components can explain approximately 50% of the observed maximum negative column ozone trend and interannual variance at northern midlatitudes in February and March. The combined empirical model also approximately simulates a leveling off or slight increase in column ozone anomalies that has been observed for some months and latitudes since the mid-1990s.
    • Intercomparison of the GOES-16 and -17 Advanced Baseline Imager with low-Earth orbit sensors

      Czapla-Myers, Jeffrey S.; Anderson, Nikolaus J.; Univ Arizona, James C Wyant Coll Opt Sci, Remote Sensing Grp (SPIE-INT SOC OPTICAL ENGINEERING, 2019-09-09)
      The GOES-16 satellite was launched on 19 Nov 2016, and it became operational as the GOES-East satellite on 18 Dec 2017. The GOES-17 satellite was launched on 1 Mar 2018, and it became the GOES-West operational satellite on 12 Feb 2019. The Advanced Baseline Imager (ABI) is one of six instruments onboard GOES-16 and -17. ABI has 16 spectral bands, a spatial resolution of 0.5 km to 2.0 km, and five times the temporal coverage of the previous GOES Imager series of sensors. The Radiometric Calibration Test Site (RadCaTS) is an automated facility at Railroad Valley, Nevada, USA, which contains ground based instruments that measure the surface reflectance and atmosphere throughout the day. It was developed by the Remote Sensing Group (RSG) of the James C. Wyant College of Optical Sciences at the University of Arizona, and it is currently used to monitor such low Earth orbit (LEO) sensors as Landsat-7 ETM+, Landsat-8 OLI, Terra and Aqua MODIS, Sentinel-2A and -2B MSI, Sentinel-3A and -3B OLCI and SLSTR, and others. The improved spectral, spatial, and temporal characteristics of ABI create an excellent opportunity to intercompare results obtained from a geosynchronous sensor to those obtained from typical LEO sensors. This work describes current efforts to validate the radiometric calibration of ABI as well as perform an intercomparison with various LEO sensors.
    • Intercomparisons of marine boundary layer cloud properties from the ARM CAP-MBL campaign and two MODIS cloud products

      Zhang, Zhibo; Dong, Xiquan; Xi, Baike; Song, Hua; Ma, Po-Lun; Ghan, Steven J.; Platnick, Steven; Minnis, Patrick; Univ Arizona, Dept Hydrol & Atmospher Sci; Physics Department; UMBC; Baltimore Maryland USA; et al. (AMER GEOPHYSICAL UNION, 2017-02-27)
      From April 2009 to December 2010, the Department of Energy Atmospheric Radiation Measurement (ARM) program carried out an observational field campaign on Graciosa Island, targeting the marine boundary layer (MBL) clouds over the Azores region. In this paper, we present an intercomparison of the MBL cloud properties, namely, cloud liquid water path (LWP), cloud optical thickness (COT), and cloud-droplet effective radius (CER), among retrievals from the ARM mobile facility and two Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products (Goddard Space Flight Center (GSFC)-MODIS and Clouds and Earth's Radiant Energy System-MODIS). A total of 63 daytime single-layer MBL cloud cases are selected for intercomparison. Comparison of collocated retrievals indicates that the two MODIS cloud products agree well on both COT and CER retrievals, with the correlation coefficient R>0.95, despite their significant difference in spatial sampling. In both MODIS products, the CER retrievals based on the 2.1 mu m band (CER2.1) are significantly larger than those based on the 3.7 mu m band (CER3.7). The GSFC-MODIS cloud product is collocated and compared with ground-based ARM observations at several temporal-spatial scales. In general, the correlation increases with more precise collocation. For the 63 selected MBL cloud cases, the GSFC-MODIS LWP and COT retrievals agree reasonably well with the ground-based observations with no apparent bias and correlation coefficient R around 0.85 and 0.70, respectively. However, GSFC-MODIS CER3.7 and CER2.1 retrievals have a lower correlation (R similar to 0.5) with the ground-based retrievals. For the 63 selected cases, they are on average larger than ground observations by about 1.5 mu m and 3.0 mu m, respectively. Taking into account that the MODIS CER retrievals are only sensitive to cloud top reduces the bias only by 0.5 mu m.
    • The interface of genomic information with the electronic health record: a points to consider statement of the American College of Medical Genetics and Genomics (ACMG)

      Grebe, Theresa A; Khushf, George; Chen, Margaret; Bailey, Dawn; Brenman, Leslie Manace; Williams, Marc S; Seaver, Laurie H; Univ Arizona, Coll Med, Phoenix Childrens Hosp (NATURE PUBLISHING GROUP, 2020-06-01)