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1. Facility-scale inventory of dairy methane emissions in California: implications for mitigation

Author

A. R. Marklein, D. Meyer, M. L. Fischer, S. Jeong, T. Rafiq, M. Carr, and F. M. Hopkins

Subjects
Environmental sciences, GE1-350, Geology, QE1-996.5
Abstract

Dairies emit roughly half of total methane (CH4) emissions in California, generating CH4 from both enteric fermentation by ruminant gut microbes and anaerobic decomposition of manure. Representation of these emission processes is essential for management and mitigation of CH4 emissions and is typically done using standardized emission factors applied at large spatial scales (e.g., state level). However, CH4-emitting activities and management decisions vary across facilities, and current inventories do not have sufficiently high spatial resolution to capture changes at this scale. Here, we develop a spatially explicit database of dairies in California, with information from operating permits and California-specific reports detailing herd demographics and manure management at the facility scale. We calculated manure management and enteric fermentation CH4 emissions using two previously published bottom-up approaches and a new farm-specific calculation developed in this work. We also estimate the effect of mitigation strategies – the use of mechanical separators and installation of anaerobic digesters – on CH4 emissions. We predict that implementation of digesters at the 106 dairies that are existing or planned in California will reduce manure CH4 emissions from those facilities by an average of 26 % and total state CH4 emissions by 5 % (or ∼36.5 Gg CH4/yr). In addition to serving as a planning tool for mitigation, this database is useful as a prior for atmospheric observation-based emissions estimates, attribution of emissions to a specific facility, and validation of CH4 emissions reductions from management changes. Raster files of the datasets and associated metadata are available from the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics (ORNL DAAC; Marklein and Hopkins, 2020; https://doi.org/10.3334/ORNLDAAC/1814).

Published
2021
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2. Characterizing uncertainties in atmospheric inversions of fossil fuel CO2 emissions in California

Author

K. Brophy, H. Graven, A. J. Manning, E. White, T. Arnold, M. L. Fischer, S. Jeong, X. Cui, and M. Rigby

Subjects
Physics, QC1-999, Chemistry, QD1-999
Abstract

Atmospheric inverse modelling has become an increasingly useful tool for evaluating emissions of greenhouse gases including methane, nitrous oxide, and synthetic gases such as hydrofluorocarbons (HFCs). Atmospheric inversions for emissions of CO2 from fossil fuel combustion (ffCO2) are currently being developed. The aim of this paper is to investigate potential errors and uncertainties related to the spatial and temporal prior representation of emissions and modelled atmospheric transport for the inversion of ffCO2 emissions in the US state of California. We perform simulation experiments based on a network of ground-based observations of CO2 concentration and radiocarbon in CO2 (a tracer of ffCO2), combining prior (bottom-up) emission models and transport models currently used in many atmospheric studies. The potential effect of errors in the spatial and temporal distribution of prior emission estimates is investigated in experiments by using perturbed versions of the emission estimates used to create the pseudo-data. The potential effect of transport error was investigated by using three different atmospheric transport models for the prior and pseudo-data simulations. We find that the magnitude of biases in posterior total state emissions arising from errors in the spatial and temporal distribution in prior emissions in these experiments are 1 %–15 % of posterior total state emissions and are generally smaller than the 2σ uncertainty in posterior emissions. Transport error in these experiments introduces biases of −10 % to +6 % into posterior total state emissions. Our results indicate that uncertainties in posterior total state ffCO2 estimates arising from the choice of prior emissions or atmospheric transport model are on the order of 15 % or less for the ground-based network in California we consider. We highlight the need for temporal variations to be included in prior emissions and for continuing efforts to evaluate and improve the representation of atmospheric transport for regional ffCO2 inversions.

Published
2019
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3. Atmospheric characterization through fused mobile airborne and surface in situ surveys: methane emissions quantification from a producing oil field

Author

I. Leifer, C. Melton, M. L. Fischer, M. Fladeland, J. Frash, W. Gore, L. T. Iraci, J. E. Marrero, J.-M. Ryoo, T. Tanaka, and E. L. Yates

Subjects
Environmental engineering, TA170-171, Earthwork. Foundations, TA715-787
Abstract

Methane (CH4) inventory uncertainties are large, requiring robust emission derivation approaches. We report on a fused airborne–surface data collection approach to derive emissions from an active oil field near Bakersfield, central California. The approach characterizes the atmosphere from the surface to above the planetary boundary layer (PBL) and combines downwind trace gas concentration anomaly (plume) above background with normal winds to derive flux. This approach does not require a well-mixed PBL; allows explicit, data-based, uncertainty evaluation; and was applied to complex topography and wind flows. In situ airborne (collected by AJAX – the Alpha Jet Atmospheric eXperiment) and mobile surface (collected by AMOG – the AutoMObile trace Gas – Surveyor) data were collected on 19 August 2015 to assess source strength. Data included an AMOG and AJAX intercomparison transect profiling from the San Joaquin Valley (SJV) floor into the Sierra Nevada (0.1–2.2 km altitude), validating a novel surface approach for atmospheric profiling by leveraging topography. The profile intercomparison found good agreement in multiple parameters for the overlapping altitude range from 500 to 1500 m for the upper 5 % of surface winds, which accounts for wind-impeding structures, i.e., terrain, trees, buildings, etc. Annualized emissions from the active oil fields were 31.3 ± 16 Gg methane and 2.4 ± 1.2 Tg carbon dioxide. Data showed the PBL was not well mixed at distances of 10–20 km downwind, highlighting the importance of the experimental design.

Published
2018
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4. Los Angeles megacity: a high-resolution land–atmosphere modelling system for urban CO2 emissions

Author

S. Feng, T. Lauvaux, S. Newman, P. Rao, R. Ahmadov, A. Deng, L. I. Díaz-Isaac, R. M. Duren, M. L. Fischer, C. Gerbig, K. R. Gurney, J. Huang, S. Jeong, Z. Li, C. E. Miller, D. O'Keeffe, R. Patarasuk, S. P. Sander, Y. Song, K. W. Wong, and Y. L. Yung

Subjects
Physics, QC1-999, Chemistry, QD1-999
Abstract

Megacities are major sources of anthropogenic fossil fuel CO2 (FFCO2) emissions. The spatial extents of these large urban systems cover areas of 10 000 km2 or more with complex topography and changing landscapes. We present a high-resolution land–atmosphere modelling system for urban CO2 emissions over the Los Angeles (LA) megacity area. The Weather Research and Forecasting (WRF)-Chem model was coupled to a very high-resolution FFCO2 emission product, Hestia-LA, to simulate atmospheric CO2 concentrations across the LA megacity at spatial resolutions as fine as ∼ 1 km. We evaluated multiple WRF configurations, selecting one that minimized errors in wind speed, wind direction, and boundary layer height as evaluated by its performance against meteorological data collected during the CalNex-LA campaign (May–June 2010). Our results show no significant difference between moderate-resolution (4 km) and high-resolution (1.3 km) simulations when evaluated against surface meteorological data, but the high-resolution configurations better resolved planetary boundary layer heights and vertical gradients in the horizontal mean winds. We coupled our WRF configuration with the Vulcan 2.2 (10 km resolution) and Hestia-LA (1.3 km resolution) fossil fuel CO2 emission products to evaluate the impact of the spatial resolution of the CO2 emission products and the meteorological transport model on the representation of spatiotemporal variability in simulated atmospheric CO2 concentrations. We find that high spatial resolution in the fossil fuel CO2 emissions is more important than in the atmospheric model to capture CO2 concentration variability across the LA megacity. Finally, we present a novel approach that employs simultaneous correlations of the simulated atmospheric CO2 fields to qualitatively evaluate the greenhouse gas measurement network over the LA megacity. Spatial correlations in the atmospheric CO2 fields reflect the coverage of individual measurement sites when a statistically significant number of sites observe emissions from a specific source or location. We conclude that elevated atmospheric CO2 concentrations over the LA megacity are composed of multiple fine-scale plumes rather than a single homogenous urban dome. Furthermore, we conclude that FFCO2 emissions monitoring in the LA megacity requires FFCO2 emissions modelling with ∼ 1 km resolution because coarser-resolution emissions modelling tends to overestimate the observational constraints on the emissions estimates.

Published
2016
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5. Toward consistency between trends in bottom-up CO2 emissions and top-down atmospheric measurements in the Los Angeles megacity

Author

S. Newman, X. Xu, K. R. Gurney, Y. K. Hsu, K. F. Li, X. Jiang, R. Keeling, S. Feng, D. O'Keefe, R. Patarasuk, K. W. Wong, P. Rao, M. L. Fischer, and Y. L. Yung

Subjects
Physics, QC1-999, Chemistry, QD1-999
Abstract

Large urban emissions of greenhouse gases result in large atmospheric enhancements relative to background that are easily measured. Using CO2 mole fractions and Δ14C and δ13C values of CO2 in the Los Angeles megacity observed in inland Pasadena (2006–2013) and coastal Palos Verdes peninsula (autumn 2009–2013), we have determined time series for CO2 contributions from fossil fuel combustion (Cff) for both sites and broken those down into contributions from petroleum and/or gasoline and natural gas burning for Pasadena. We find a 10 % reduction in Pasadena Cff during the Great Recession of 2008–2010, which is consistent with the bottom-up inventory determined by the California Air Resources Board. The isotopic variations and total atmospheric CO2 from our observations are used to infer seasonality of natural gas and petroleum combustion. The trend of CO2 contributions to the atmosphere from natural gas combustion is out of phase with the seasonal cycle of total natural gas combustion seasonal patterns in bottom-up inventories but is consistent with the seasonality of natural gas usage by the area's electricity generating power plants. For petroleum, the inferred seasonality of CO2 contributions from burning petroleum is delayed by several months relative to usage indicated by statewide gasoline taxes. Using the high-resolution Hestia-LA data product to compare Cff from parts of the basin sampled by winds at different times of year, we find that variations in observed fossil fuel CO2 reflect seasonal variations in wind direction. The seasonality of the local CO2 excess from fossil fuel combustion along the coast, on Palos Verdes peninsula, is higher in autumn and winter than spring and summer, almost completely out of phase with that from Pasadena, also because of the annual variations of winds in the region. Variations in fossil fuel CO2 signals are consistent with sampling the bottom-up Hestia-LA fossil CO2 emissions product for sub-city source regions in the LA megacity domain when wind directions are considered.

Published
2016
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6. CO2, CO, and CH4 measurements from tall towers in the NOAA Earth System Research Laboratory's Global Greenhouse Gas Reference Network: instrumentation, uncertainty analysis, and recommendations for future high-accuracy greenhouse gas monitoring efforts

Author

A. E. Andrews, J. D. Kofler, M. E. Trudeau, J. C. Williams, D. H. Neff, K. A. Masarie, D. Y. Chao, D. R. Kitzis, P. C. Novelli, C. L. Zhao, E. J. Dlugokencky, P. M. Lang, M. J. Crotwell, M. L. Fischer, M. J. Parker, J. T. Lee, D. D. Baumann, A. R. Desai, C. O. Stanier, S. F. J. De Wekker, D. E. Wolfe, J. W. Munger, and P. P. Tans

Subjects
Environmental engineering, TA170-171, Earthwork. Foundations, TA715-787
Abstract

A reliable and precise in situ CO2 and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Global Greenhouse Gas Reference Network. The network uses very tall (> 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary-layer trace-gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO2 and CH4. The long-term stability of the systems in the field is typically better than 0.1 ppm for CO2, 6 ppb for CO, and 0.5 ppb for CH4, as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures, and flow rates, that are inputs for automated alerts and quality control algorithms. Detailed and time-dependent uncertainty estimates have been constructed for all of the gases, and the uncertainty framework could be readily adapted to other species or analysis systems. The design emphasizes use of off-the-shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with > 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high-accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.

Published
2014
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7. Biases in regional carbon budgets from covariation of surface fluxes and weather in transport model inversions

Author

I. N. Williams, W. J. Riley, M. S. Torn, S. C. Biraud, and M. L. Fischer

Subjects
Physics, QC1-999, Chemistry, QD1-999
Abstract

Recent advances in atmospheric transport model inversions could significantly reduce uncertainties in land carbon uptake through the assimilation of CO2 concentration measurements at weekly and shorter timescales. The potential of these measurements for reducing biases in estimated land carbon sinks depends on the strength of covariation between surface fluxes and atmospheric transport at these timescales and how well transport models represent this covariation. Daily to seasonal covariation of surface fluxes and atmospheric transport was estimated in observations at the US Southern Great Plains Atmospheric Radiation Measurement Climate Research Facility, and compared to an atmospheric transport model inversion (CarbonTracker). Covariation of transport and surface fluxes was stronger in CarbonTracker than in observations on synoptic (daily to weekly) timescales, with a wet year (2007) having significant covariation compared to a dry year (2006). Differences between observed and CarbonTracker synoptic covariation resulted in a 0.3 ppm CO2 enhancement in boundary layer concentrations during the growing season, and a corresponding enhancement in carbon uptake by 13% of the seasonal cycle amplitude in 2007, as estimated by an offline simplified transport model. This synoptic rectification of surface flux variability was of similar magnitude to the interannual variability in carbon sinks alone, and indicates that interannual variability in the inversions can be affected by biases in simulated synoptic rectifier effects. The most significant covariation of surface fluxes and transport had periodicities of 10 days and greater, suggesting that surface flux inversions would benefit from improved simulations of the effects of soil moisture on boundary layer heights and surface CO2 fluxes. Soil moisture remote sensing could be used along with CO2 concentration measurements to further constrain atmospheric transport model inversions.

Published
2014
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8. Diurnal tracking of anthropogenic CO2 emissions in the Los Angeles basin megacity during spring 2010

Author

S. Newman, S. Jeong, M. L. Fischer, X. Xu, C. L. Haman, B. Lefer, S. Alvarez, B. Rappenglueck, E. A. Kort, A. E. Andrews, J. Peischl, K. R. Gurney, C. E. Miller, and Y. L. Yung

Subjects
Physics, QC1-999, Chemistry, QD1-999
Abstract

Attributing observed CO2 variations to human or natural cause is critical to deducing and tracking emissions from observations. We have used in situ CO2, CO, and planetary boundary layer height (PBLH) measurements recorded during the CalNex-LA (CARB et al., 2008) ground campaign of 15 May–15 June 2010, in Pasadena, CA, to deduce the diurnally varying anthropogenic component of observed CO2 in the megacity of Los Angeles (LA). This affordable and simple technique, validated by carbon isotope observations and WRF-STILT (Weather Research and Forecasting model – Stochastic Time-Inverted Lagrangian Transport model) predictions, is shown to robustly attribute observed CO2 variation to anthropogenic or biogenic origin over the entire diurnal cycle. During CalNex-LA, local fossil fuel combustion contributed up to ~50% of the observed CO2 enhancement overnight, and ~100% of the enhancement near midday. This suggests that sufficiently accurate total column CO2 observations recorded near midday, such as those from the GOSAT or OCO-2 satellites, can potentially be used to track anthropogenic emissions from the LA megacity.

Published
2013
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9. Assessment of fossil fuel carbon dioxide and other anthropogenic trace gas emissions from airborne measurements over Sacramento, California in spring 2009

Author

J. C. Turnbull, A. Karion, M. L. Fischer, I. Faloona, T. Guilderson, S. J. Lehman, B. R. Miller, J. B. Miller, S. Montzka, T. Sherwood, S. Saripalli, C. Sweeney, and P. P. Tans

Subjects
Physics, QC1-999, Chemistry, QD1-999
Abstract

Direct quantification of fossil fuel CO2 (CO2ff) in atmospheric samples can be used to examine several carbon cycle and air quality questions. We collected in situ CO2, CO, and CH4 measurements and flask samples in the boundary layer and free troposphere over Sacramento, California, USA, during two aircraft flights over and downwind of this urban area during spring of 2009. The flask samples were analyzed for Δ14CO2 and CO2 to determine the recently added CO2ff mole fraction. A suite of greenhouse and other trace gases, including hydrocarbons and halocarbons, were measured in the same samples. Strong correlations were observed between CO2ff and numerous trace gases associated with urban emissions. From these correlations we estimate emission ratios between CO2ff and these species, and compare these with bottom-up inventory-derived estimates. Recent county level inventory estimates for carbon monoxide (CO) and benzene from the California Air Resources Board CEPAM database are in good agreement with our measured emission ratios, whereas older emissions inventories appear to overestimate emissions of these gases by a factor of two. For most other trace species, there are substantial differences (200–500%) between our measured emission ratios and those derived from available emission inventories. For the first flight, we combine in situ CO measurements with the measured CO:CO2ff emission ratio of 14 ± 2 ppbCO/ppmCO2 to derive an estimate of CO2ff mole fraction throughout this flight, and also estimate the biospheric CO2 mixing ratio (CO2bio) from the difference of total and fossil CO2. The resulting CO2bio varies dramatically from up to 8 ± 2 ppm in the urban plume to −6 ± 1 ppm in the surrounding boundary layer air. Finally, we use the in situ estimates of CO2ff mole fraction to infer total fossil fuel CO2 emissions from the Sacramento region, using a mass balance approach. The resulting emissions are uncertain to within a factor of two due to uncertainties in wind speed and boundary layer height. Nevertheless, this first attempt to estimate urban-scale CO2ff from atmospheric radiocarbon measurements shows that CO2ff can be used to verify and improve emission inventories for many poorly known anthropogenic species, separate biospheric CO2, and indicates the potential to constrain CO2ff emissions if transport uncertainties are reduced.

Published
2011
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10. Calibration of the Total Carbon Column Observing Network using aircraft profile data

Author

D. Wunch, G. C. Toon, P. O. Wennberg, S. C. Wofsy, B. B. Stephens, M. L. Fischer, O. Uchino, J. B. Abshire, P. Bernath, S. C. Biraud, J.-F. L. Blavier, C. Boone, K. P. Bowman, E. V. Browell, T. Campos, B. J. Connor, B. C. Daube, N. M. Deutscher, M. Diao, J. W. Elkins, C. Gerbig, E. Gottlieb, D. W. T. Griffith, D. F. Hurst, R. Jiménez, G. Keppel-Aleks, E. A. Kort, R. Macatangay, T. Machida, H. Matsueda, F. Moore, I. Morino, S. Park, J. Robinson, C. M. Roehl, Y. Sawa, V. Sherlock, C. Sweeney, T. Tanaka, and M. A. Zondlo

Subjects
Environmental engineering, TA170-171, Earthwork. Foundations, TA715-787
Abstract

The Total Carbon Column Observing Network (TCCON) produces precise measurements of the column average dry-air mole fractions of CO2, CO, CH4, N2O and H2O at a variety of sites worldwide. These observations rely on spectroscopic parameters that are not known with sufficient accuracy to compute total columns that can be used in combination with in situ measurements. The TCCON must therefore be calibrated to World Meteorological Organization (WMO) in situ trace gas measurement scales. We present a calibration of TCCON data using WMO-scale instrumentation aboard aircraft that measured profiles over four TCCON stations during 2008 and 2009. These calibrations are compared with similar observations made in 2004 and 2006. The results indicate that a single, global calibration factor for each gas accurately captures the TCCON total column data within error.

Published
2010
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11. Characterization of Tropospheric Emission Spectrometer (TES) CO2 for carbon cycle science

Author

S. C. Biraud, M. L. Fischer, H. Matsueda, Y. Sawa, T. Machida, K. W. Bowman, J. R. Worden, F. W. Irion, R. Nassar, D. B. A. Jones, S. S. Kulawik, and A. R. Jacobson

Subjects
Physics, QC1-999, Chemistry, QD1-999
Abstract

We present carbon dioxide (CO2) estimates from the Tropospheric Emission Spectrometer (TES) on the EOS-Aura satellite launched in 2004. For observations between 40° S and 45° N, we find about 1 degree of freedom with peak sensitivity at 511 hPa. The estimated error is ~10 ppm for a single target and 1.3–2.3 ppm for monthly averages on spatial scales of 20°×30°. Monthly spatially-averaged TES data from 2005–2008 processed with a uniform initial guess and prior are compared to CONTRAIL aircraft data over the Pacific ocean, aircraft data at the Southern Great Plains (SGP) ARM site in the southern US, and the Mauna Loa and Samoa surface stations. Comparisons to Mauna Loa data show a correlation of 0.92, a standard deviation of 1.3 ppm, a predicted error of 1.2 ppm, and a ~2% low bias, which is subsequently corrected. Comparisons to SGP aircraft data over land show a correlation of 0.67 and a standard deviation of 2.3 ppm. TES data between 40° S and 45° N for 2006–2007 are compared to surface flask data, GLOBALVIEW, the Atmospheric Infrared Sounder (AIRS), and CarbonTracker. Comparison to GLOBALVIEW-CO2 ocean surface sites shows a correlation of 0.60 which drops when TES is offset in latitude, longitude, or time. At these same locations, TES shows a 0.62 and 0.67 correlation to CarbonTracker at the surface and 5 km, respectively. We also conducted an observing system simulation experiment to assess the potential utility of the TES data for inverse modeling of CO2 fluxes. We find that if biases in the data and model are well characterized, the averaged data have the potential to provide sufficient information to significantly reduce uncertainty on annual estimates of regional CO2 sources and sinks. Averaged pseudo-data at 10°×10° reduced uncertainty in flux estimates by as much as 70% for some tropical regions.

Published
2010
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12. Loxosceles spider bites in the state of Paraná, Brazil: 1993-2000

Author

E. Marques-da-Silva, R. Souza-Santos, M. L. Fischer, and G. B. G. Rubio

Subjects
Loxosceles, spiders, epidemiology, venomous animals, Brazil, Arctic medicine. Tropical medicine, RC955-962, Toxicology. Poisons, RA1190-1270, Zoology, QL1-991
Abstract

This study presents the epidemiological analysis of 20,699 reported spider bites involving the Loxosceles genus in the state of Paraná, Brazil, from 1993 to 2000. The incidence rate in the period was 290.24/100,000 inhabitants. The results show that 95.04% of the accidents occurred in two Health Regions of the state: greater metropolitan Curitiba (92.9%) and Irati (2.14%). The major incidence was recorded in greater metropolitan Curitiba (559.1/100,000). Loxosceles bites were more frequent in females (61%) than in males. Antivenin therapy was not necessary in 95.4% (19,662) of the cases. From the cases in which information about the time elapsed between the bite and medical treatment was recorded (9,679), 31.8% received treatment from 6 to 48 hours after the bite. Among the cases with severity rate recorded (12,096), 2.1% were severe, 50.4% moderate, and 47.4% mild. Seven deaths from Loxosceles bites were recorded, corresponding to a fatality rate of 0.03%.

Published
2006
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13. Effect of a multimodal pain management protocol and age on wound healing after thermal disbudding of female German Holstein calves

Author

J, Kretschmann, L, Früchtl, M-L, Fischer, M, Kaiser, H, Müller, J, Spilke, N, Mielenz, G, Möbius, L, Bittner-Schwerda, I, Steinhöfel, W, Baumgartner, and A, Starke

Subjects
Wound Healing, General Veterinary, Animals, Pain, Pain Management, Cattle, Female, Clinical Trials, Veterinary as Topic, Prospective Studies, Horns
Abstract

Hot-iron disbudding of calves is a stressful and painful procedure and leaves a burn wound. Pain management procedures and the effects of hot-iron disbudding on biochemical markers of pain perception and stress response have been widely investigated in recent years. The aim of this study was to investigate the potential effects of pain management and age of the calf on the healing of burn wounds caused by disbudding. 327 healthy female German Holstein calves were included in this randomised, triple-blinded, prospective study. Calves were either disbudded at the age of four to 10 or 15 to 28 days using a gas-powered hot iron. Each calf was randomly allocated to one of nine possible treatment groups (BG). All calves received either the active ingredients to be tested (xylazine hydrochloride with 0.2 or 0.05 mg / kg body mass (BM) intramuscular for sedation, procaine hydrochloride (2 %) each 8 ml locally on both sides subcutaneously (SC) to the cornual nerves, meloxicam with 0,5 mg / kg BM SC for anti-inflammatory purposes) or an identical amount of saline solution (placebo). Calves in the group `thermE` and `ScheinE` received only placebo. In group `ScheinE` disbudding was simulated and in `thermE` it was carried out. The calves were clinically monitored starting one day before and ending 28 days after the procedure and the burn wounds were assessed. Both the rectal temperature and parameters of wound healing changed significantly during the study period and had characteristic profiles over time. Wound healing was not influenced by the different analgesic protocols, indicating that a multimodal analgesia does not pose a risk for wound healing after thermal disbudding. There were no observed differences between the age groups. The results of this study show, that disbudding of young calves and a multimodal pain management protocol does not affect wound healing in calves.Die thermische Zerstörung der Hornanlage (ZHA) von Kälbern stellt einen Eingriff dar, welcher mit Schmerz und Stress verbunden ist und eine Verbrennungswunde hinterlässt. Verschiedene Verfahren der Schmerzausschaltung sowie der Einfluss der thermischen ZHA auf Marker der Schmerz- und Stressreaktion wurden bereits evaluiert. Ziel der vorliegenden Studie war es zu prüfen, inwieweit das Schmerzmanagement selbst oder das Alter der Kälber die Wundheilung thermisch bedingter Wunden nach ZHA beeinflusst. In die randomisierte, dreifach verblindete, prospektive Studie wurden 327 gesunde, weibliche Deutsch-Holstein-Kälber einbezogen. Die ZHA erfolgte entweder zwischen dem vierten und 10. oder dem 15. und 28. Lebenstag mit einem gasbetriebenen Enthornungsgerät. Jedes Kalb wurde einer von neun Behandlungsgruppen (BG) zugelost. Alle Kälber bekamen entweder die zu testenden Wirkstoffe (Xylazinhydrochlorid mit 0,2 oder 0,05 mg/kg Körpermasse (KM) zur Sedation intramuskulär, Procainhydrochlorid (2 %) je 8 ml lokal beidseitig subkutan (SC) an die Rr. cornuales, Meloxicam mit 0,5 mg/kg KM SC zur Entzündungshemmung/Analgesie) oder eine identische Menge an isotoner Kochsalzlösung (Placebo) injiziert. Kälber der Gruppe `thermE` und `ScheinE` erhielten nur Placebo, bei `ScheinE` wurde die ZHA simuliert, bei `thermE` durchgeführt. Die Gruppe `Melo` erhielt nur Meloxicam, `LA` nur Procainhydrochlorid, `Melo-LA` Meloxicam + Procainhydrochlorid, `Seda 0,2` nur Xylazinhydrochlorid, `Seda 0,05-Melo` und `Seda 0,2-Melo ` (Xylazinhydrochlorid + Meloxicam), und `Seda 0,2-Melo-LA` alle zu testenden Wirkstoffe. Die Kälber wurden von einem Tag vor bis 28 Tage nach dem Eingriff klinisch überwacht und die Wunden befundet. Sowohl die inneren Körpertemperatur (IKT) als auch die Merkmale der Wundheilung unterschieden sich signifikant zwischen den einzelnen Untersuchungstagen und zeigten einen zeitlichen Verlauf. Die Wundheilung wurde durch die verschiedenen Analgetika oder deren Kombinationen nicht beeinflusst, eine multimodale Analgesie stellt demnach kein Risiko für die Wundheilung nach ZHA unter Praxisbedingungen dar. Zwischen den Altersgruppen wurden keine Unterschiede in der Wundheilung beobachtet. Die ZHA von Kälbern kann unter Praxisbedingungen demnach bereits früh und unter Ausschöpfung aller analgetischen Möglichkeiten erfolgen.L’ébourgeonnage thermique des veaux est une procédure stressante et douloureuse qui laisse une brûlure. Les procédures de gestion de la douleur et les effets de l’ébourgeonnage thermique sur les marqueurs biochimiques de la perception de la douleur et de la réponse au stress ont été largement étudiés ces dernières années. Le but de cette étude était d’étudier les effets potentiels de la gestion de la douleur et de l’âge du veau sur la cicatrisation des brûlures causées par l’ébourgeonnage. 327 veaux Holstein allemands femelles en bonne santé ont été inclus dans cette étude prospective randomisée en triple aveugle. Les veaux ont été soit ébourgeonnés à l’âge de 4 à 10 jours ou de 15 à 28 jours à l’aide d’un thermocautère à gaz. Chaque veau a été réparti au hasard dans l’un des neuf groupes de traitement possibles (BG). Tous les veaux ont reçu soit les principes actifs à tester (chlorhydrate de xylazine à 0,2 ou 0,05 mg/kg de masse corporelle (BM) par voie intramusculaire pour sédation, chlorhydrate de procaïne (2 %) 8 ml localement des deux côtés par voie sous-cutanée (SC) jusqu’aux nerfs cornuaux , méloxicam à 0,5 mg/kg de masse corporelle SC à visée anti-inflammatoire) ou une quantité identique de solution saline (placebo). Les veaux du groupe « thermE » et « ScheinE » ont reçu uniquement un placebo. Dans le groupe ‹ScheinE’ l’ébourgeonnage a été simulé et dans ‘thermE’ il a été réalisé. Le groupe « Melo » n’a reçu que du méloxicam, le groupe « LA » uniquement du chlorhydrate de procaïne, le grpoupe « Melo-LA » du méloxicam + chlorhydrate de procaïne, le groupe « Seda 0,2 » uniquement du chlorhydrate de xylazine, les groupes « Seda 0,05-Melo » et« Seda 0,2 -Melo » duchlorhydrate de xylazine et du méloxicam), et le groupe « Seda 0,2-Melo-LA » toutes les substances actives à tester. Les veaux ont été suivis cliniquement en commençant un jour avant et en terminant 28 jours après la procédure et les brûlures ont été évaluées. La température rectale et les paramètres de cicatrisation des plaies ont changé de manière significative au cours de la période d’étude et ont eu des profils caractéristiques au fil du temps. La cicatrisation n’a pas été influencée par les différents protocoles analgésiques, ce qui indique qu’une analgésie multimodale ne présente pas de risque quant à la cicatrisation après ébourgeonnage thermique. Aucune différence n’a été observée entre les groupes d’âge. Les résultats de cette étude montrent que l’ébourgeonnage des jeunes veaux et un protocole multimodal de gestion de la douleur n’affectent pas la cicatrisation des veaux.La decornazione termica dei vitelli è una procedura che è associata a dolore e stress e lascia una ferita da ustione. Diversi metodi di analgesia e l’influenza della decornazione termica sui marcatori del dolore e della risposta allo stress sono già stati valutati. Lo scopo del presente studio era quello di esaminare la misura in cui, la gestione del dolore stesso o l’età dei vitelli, influenzi la guarigione delle ferite provocate dopo la decornazione termica. Lo studio randomizzato, in triplo cieco e prospettico ha incluso 327 vitelli sani di razza Holstein tedesca. La decornazione è stata eseguita tra il quarto e il decimo o il quindicesimo e il ventottesimo giorno di vita utilizzando un dispositivo di decornazione a gas. Ogni vitello è stato assegnato a uno dei nove gruppi di trattamento (GT). A tutti i vitelli sono stati iniettati o gli agenti da testare (xilazina cloridrato a 0,2 o 0,05 mg/kg di massa corporea (MC) per via intramuscolare per la sedazione, procaina cloridrato (2 %) 8 ml ciascuno per via locale bilaterale sottocutanea (SC) ai rr. cornuales, meloxicam a 0,5 mg/kg KM SC per antinfiammatorio/analgesia) o una quantità identica di soluzione salina isotonica (placebo). I vitelli nei gruppi `thermE` e `ScheinE` hanno ricevuto solo placebo; la decornazione è stata simulata in `ScheinE` ed eseguita in `thermE`. Il gruppo `Melo` ha ricevuto solo meloxicam, `LA` solo procaina cloridrato, `Melo-LA` meloxicam + procaina cloridrato, `Seda 0,2` solo xilazina cloridrato, `Seda 0,05-Melo` e `Seda 0,2-Melo` (xilazina cloridrato + meloxicam), e `Seda 0,2-Melo-LA` tutti gli agenti da testare. I vitelli sono stati monitorati clinicamente da un giorno prima a 28 giorni dopo la procedura e sono state valutate le ferite. Sia la temperatura corporea interna (TCI) che le caratteristiche di guarigione della ferita differivano significativamente tra i giorni di studio e mostravano un andamento temporale. La guarigione della ferita non è stata influenzata dai diversi analgesici o dalle loro combinazioni; l’analgesia multimodale non rappresenta quindi un rischio per la guarigione della ferita dopo la decornazione in condizioni reali. Non sono state osservate differenze nella guarigione delle ferite tra i gruppi di età. Pertanto, la decornazione dei vitelli in condizioni reali può essere eseguita presto e con l’esaurimento di tutte le possibilità analgesiche.

Published
2021
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15. A comprehensive study of the polypropylene fibers reinforced conventional concrete

Author

J. P. Callegari, L. M. L. Fischer, F. U. Farrão, and M. S. Liberato

Subjects
water absorption, heat resistance, concrete, polypropylene fiber, Composite, lcsh:A, composite, concrete, polypropylene fiber, compressive strength, water absorption, heat resistance, lcsh:General Works, compressive strength
Abstract

The aim of this study was to study of the properties and characterization of conventional concrete and reinforced concrete with polypropylene fiber. Themes were theoretically addressed: concrete, composites, fibers, polypropylene fibers. In addition, practical tests were carried out, with test specimens of these two materials, of compressive strength, water absorption and heat resistance, to verify the differences in the properties of these two materials. The tests were completed and it can be noted that the application of the polypropylene fiber in the concrete as reinforcement for the concrete is satisfactory, because the water absorption test obtained similar results for the two materials, and performing the test of resistance to compression, it was observed that the test specimens with fiber, obtained better results than the conventional concrete. Finally, the heat resistance test showed that the fiber actually degrades in the temperature range informed by the supplier, being another advantage for its application in tunnels, in front of the fires.

Published
2019

16. [Thermographic examination of head surface temperatures of calves under field conditions]

Author

Matthias Kaiser, S. Getto, J. Kretschmann, L. Scherf, Norbert Mielenz, Lilli Bittner, Alexander Starke, Gerd Möbius, Hendrik Müller, and M. L. Fischer

Subjects
Materials science, General Veterinary, Infrared, Humidity, Thermographic camera, law.invention, Body Temperature, Animal science, law, Thermography, Head surface, Head (vessel), Animals, Cattle, Animal Husbandry, Head, Field conditions, Muzzle, Monitoring, Physiologic
Abstract

Thermographic examination of 157 German Holstein heifer calves was performed to investigate the feasibility of this technique for on-farm recording of surface temperature of the head and to examine potential factors that affect the recordings. Baseline values were obtained from six defined locations on the head including both eyes, both horn buds, the muzzle and the mucous membrane of the muzzle using a high-end thermographic camera (ThermoPro TP8, Firma DIAS Infrared GmbH). Evaluation of the influence of various factors on thermographic measurements showed that ambient temperature had the largest effect on surface temperature of the head (regression coefficient, 0.10 to 0.32, p ≤ 0.01) whereas humidity had no effect (in t-test p ≥ 0.33 over all locations). There was a no correlation between rectal temperature and surface temperature (rp ≤ 0.05). The surface temperature decreased with increasing age of the calves (regression coefficient, - 0.42 to - 0.14, p ≤ 0.01). The agreement between double readings made shortly after one another was excellent at all locations (r ≥ 0.95). The emission of infrared energy varied among different locations; the most infrared energy was emitted by the eyes and the least by the muzzle. Paired locations (eyes and horn buds) had symmetric emission patterns of infrared energy. Measuring the surface temperature of the head of calves in their normal barn environment using a standardised protocol was feasible and thus could potentially be used for monitoring calves under field conditions.Mittels Infrarot-Thermographie wurden 157 gesunde, weibliche Deutsch-Holstein Kälber thermographisch untersucht. Es war das Ziel der Studie, Oberflächentemperaturen an definierten Lokalisationen im Kopfbereich von Deutsch-Holstein Kälbern unter Stallbedingungen standardisiert zu erfassen und die Einflussfaktoren auf die Ergebnisse zu charakterisieren. Im Rahmen der Studie wurden mittels einer High-End Wärmebildkamera (ThermoPro TP8, Firma DIAS Infrared GmbH) Ruhewerte von sechs Lokalisationen im Kopfbereich (linkes Auge (liAu), rechtes Auge (reAu), linke Hornanlage (liHa), rechte Horn­anlage (reHa), Flotzmaul (FM), Schleimhaut des Flotzmauls (SHFM)) erfasst. Die Umgebungstemperatur hatte einen Einfluss auf die Oberflächentemperaturen (r = 0,10 bis 0,32; p ≤ 0,01). Die Luftfeuchtigkeit wirkte sich nicht auf die Messergebnisse aus (im t-Test p ≥ 0,33 über alle Lokalisationen) . Es war kein Zusammenhang zwischen der rektal erfassten Körperinnentemperatur und den thermographisch ermittelten Oberflächentemperaturen feststellbar (rp ≤ 0,05). Mit zunehmendem Alter der Tiere konnte ein Abfall der Oberflächentemperaturen beobachtet werden (r = – 0,42 bis – 0,14; p ≤ 0,01). Die Wiederholbarkeit der thermographischen Doppelmessungen war sehr gut (r ≥ 0,95). An den verschiedenen Lokalisationen wurde Wärme in unterschiedlichem Maße emittiert, wobei die Augen die höchsten und das Flotzmaul die niedrigsten Oberflächentemperaturen aufwiesen. Die paarigen Lokalisationen (liAu:reAu, liHA:reHa) wiesen ein symmetrisches Wärmestrahlungsmuster auf. Die Thermographie kann im Kopfbereich von weiblichen Deutsch-Holstein Kälbern im Milchviehbetrieb zur Erfassung von unterschiedlichen Oberflächentemperaturen eingesetzt werden.Un total de 157 veaux femelles provenant d’un troupeau de 1 500 vaches holstein ont été examinées au moyen d’une caméra thermographique haut de gamme (Ther-moPro TP8, Firma DIAS Infrared GmbH). Le but de la présente étude était d’étudier la faisabilité de cette technique pour l’enregistrement à la ferme de la température de surface de la tête de veaux laitiers et d’examiner les facteurs potentiels qui affectent les enregistrements. Tous les veaux ont été doucement tenus par une personne formée afin de normaliser la procédure. Les valeurs de base ont été obtenues à partir de six endroits définis sur la tête, y compris les deux yeux, les deux boutons de corne, le mufle et la muqueuse du museau. L’évaluation de l’influence de divers facteurs sur les mesures thermographiques a montré que la température ambiante avait le plus grand effet sur la température de surface de la tête (coefficient de régression, 0,10 à 0,32, p ≤ 0,01) alors que l’humidité n’avait aucun effet (dans le test t, p ≥ 0,33 sur tous les lieux). Il n’y avait pas de corrélation entre la température rectale et la température de surface (rp ≤ 0,05). La température de surface diminuait avec l’âge des veaux (coefficient de régression, -0,42 à -0,14, p ≤ 0,01). La concordance entre les lectures doubles faites peu de temps après les autres était excellente dans tous les sites (r ≥ 0,95) L’émission d’énergie infrarouge variait selon les endroits. L’énergie infrarouge la plus importante a été émise par les yeux et la plus faible par le mufle. Les sites appariés (yeux et cornes) présentaient des profils d’émission symétriques d’énergie infrarouge. La thermographie peut être utilisée chez veaux Holstein pour la détection de différentes température de surface de la tête.La termografia a infrarossi è un metodo di imaging non invasivo, rapido e senza contatto, per la misurazione delle temperature superficiali utilizzata per diverse indicazioni mediche in medicina veterinaria. L’obiettivo del presente studio era quello di studiare la fattibilità di questa tecnica per la registrazione in stalla della temperatura superficiale della testa dei vitelli Holstein tedeschi e di esaminare i potenziali fattori che influenzano i risultati. A tale scopo, 157 giovenche sane di razza tedesca Holstein di un’azienda da latte con 1500 vacche sono state esaminate termograficamente con una telecamera termografica di fascia alta (ThermoPro TP8, DIAS Infrared GmbH). Tutti i vitelli sono stati trattenuti delicatamente da una persona addestrata per standardizzare la procedura. Nell’ambito dello studio si sono registrati i valori di riferimento ottenuti da sei posizioni localizzate sulla testa, (occhio sinistro (liAu), occhio destro (reAu), corno sinistro (liHa), corno destro (reHa), muso (FM), mucosa dello specchio nasolabiale (SHFM)). È stato esaminato in che modo determinati fattori hanno influenzato le misurazioni termografiche. La temperatura ambientale ha avuto la maggiore ­influenza sulle temperature superficiali (coefficienti di regressione da 0,10 a 0,32; p ≤ 0,01). L’umidità non ha influenzato i risultati della misurazione (nel test t p ≥ 0,33 su tutte le posizioni). Non vi è stata nessuna relazione tra la temperatura rettale registrata e la temperatura superficiale rilevabile termograficamente (rp ≤ 0,05), D’altra parte, con l’aumentare dell’età degli animali si può osservare una diminuzione delle temperature superficiali (coefficienti di regressione da - 0,42 a - 0,14; p ≤ 0,01). La ripetibilità delle doppie misurazioni termografiche consecutive per ogni localizzazione è stata molto buona (r ≥ 0,95). Il calore veniva emesso a vari livelli nelle varie posizioni, dove gli occhi avevano le temperature superficiali più alte e lo specchio nasolabiale le temperature superficiali più basse. Le posizioni accoppiate (liAu:reAu, liHA:reHa) presentavano modelli di radiazione simmetrica del calore. Pertanto, nelle aziende, un uso della termografia per il rilevamento delle temperature superficiali nell’area della testa delle giovenche di razza tedesca Holstein è possibile. Queste misurazioni forniscono la base per un potenziale uso della termografia per monitorare la salute dei vitelli.

Published
2019

17. Carbon, water, and heat flux responses to experimental burning and drought in a tallgrass prairie

Author

Sébastien C. Biraud, G. L. Doyle, M. L. Fischer, David P. Billesbach, Margaret S. Torn, and Brian K. Northup

Subjects
Atmospheric Science, Global and Planetary Change, Biomass (ecology), Ecology, Eddy covariance, Growing season, Forestry, Sensible heat, Agronomy, Latent heat, Litter, Environmental science, Water-use efficiency, Agronomy and Crop Science, Water content
Abstract

Drought and fire are common disturbances to grassland ecosystems. We report two years of eddy covariance ecosystem–atmosphere fluxes and biometric variables measured in nearby burned and unburned pastures in the US Southern Great Plains. Over the course of the experiment, annual precipitation (∼600 mm yr−1) was lower than the long term mean (∼860 mm yr−1). Soil moisture decreased from productive conditions in March 2005 dry, unproductive conditions during the growing season starting in March 2006. Just prior to the burn in early March 2005, burned and unburned pastures contained 520 ± 60 and 360 ± 40 g C m−2 of total above ground biomass (AGB) and litter, respectively. The fire removed approximately 200 g C m−2 of litter and biomass. In the 2005 growing season following the burn, maximum green AGB was 450 ± 60 and 270 ± 40 g C m−2, with corresponding cumulative annual net ecosystem carbon exchange (NEE) of −330 and −150 g C m−2 for the burned and unburned pastures, respectively. In contrast to NEE, cumulative mean sensible heat and water fluxes were approximately equal in both pastures during the growing season, suggesting either an increase in water use efficiency or a decrease in evaporation in the burned relative to the unburned pasture. In the 2006 growing season, dry conditions decreased carbon uptake and latent heat, and increased sensible heat fluxes. Peak AGB was reduced to 210 ± 30 g C m−2 and 140 ± 30 g C m−2 in the burned and unburned pastures, respectively, while NEE was near zero. These results suggest that the lack of precipitation was responsible for most of the interannual variation in carbon exchange for these un-irrigated prairie pastures.

Published
2012
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18. Full-Column Greenhouse Gas Sampling 2012-2014 Final Campaign Report

Author

C. Sweeney and M. L. Fischer

Subjects
Earth system science, Atmospheric radiation, Biogeochemical cycle, Geography, Meteorology, Observatory, Greenhouse gas, Sampling (statistics), Satellite, Column (database)
Abstract

The vertical distributions of CO2, CH4, and other gases provide important constraints when determining terrestrial and ocean sources and sinks of carbon and other biogeochemical processes in the Earth system. The U.S. Department of Energy's (DOE) Office of Biological and Environmental Research and the National Oceanic and Atmospheric Administration's Earth System Research Laboratory to quantify the vertically resolved distribution of atmospheric carbon-cycle gases(CO2, CH4 ) within approximately 99% of the atmospheric column at the DOE ’s Atmospheric Radiation Measurement Southern Great Plains (SGP) site in Oklahoma . During the 2012 to 2014 campaign period, 12 successful Air C ore flights were conducted from the SGP site . In addition to providing critical data for evaluating remote sensing and earth system models, valuable lessons were learned that motivate improvements to the sampling and recovery systems and campaign logistics . With the launch of the Orbiting Carbon Observatory - 2 (OCO - 2) and Greenhouse gases Observing Satellite ( GOSAT ) satellites, we look forward to proposing additional sampling and analysis efforts at the SGP site and at other sites to characterize the vertical distribution of CO2, CH4 over time and space.

Published
2016
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19. Direct and indirect effects of climatic variations on the interannual variability in net ecosystem exchange across terrestrial ecosystems

Author

Mika Aurela, David P. Billesbach, Walter C. Oechel, Yiqi Luo, Huimin Wang, Krisztina Pintér, Shuli Niu, Junjiong Shao, Xuhui Zhou, Margaret S. Torn, Jiquan Chen, Bo Li, Zoltán Nagy, Yuling Fu, Yongtao He, Lianhong Gu, Peili Shi, Rosvel Bracho, Thomas Kolb, Andrew E. Suyker, Peter D. Blanken, Guirui Yu, Andrej Varlagin, Junhui Zhang, Yingnian Li, Shijie Han, Junhua Yan, and M. L. Fischer

Subjects
0106 biological sciences, Atmospheric Science, 010504 meteorology & atmospheric sciences, direct and indirect effects, Vapour Pressure Deficit, net ecosystem exchange, interannual variability, Environmental Science and Management, Biome, lcsh:QC851-999, climatic variations, 010603 evolutionary biology, 01 natural sciences, Atmospheric Sciences, physiological parameters, relative importance, Meteorology & Atmospheric Sciences, Ecosystem, 0105 earth and related environmental sciences, Ecology, Phenology, Evergreen, Deciduous, Environmental science, lcsh:Meteorology. Climatology, Terrestrial ecosystem, Ecosystem respiration
Abstract

Climatic variables not only directly affect the interannual variability (IAV) in net ecosystem exchange of CO 2 (NEE) but also indirectly drive it by changing the physiological parameters. Identifying these direct and indirect paths can reveal the underlying mechanisms of carbon (C) dynamics. In this study, we applied a path analysis using flux data from 65 sites to quantify the direct and indirect climatic effects on IAV in NEE and to evaluate the potential relationships among the climatic variables and physiological parameters that represent physiology and phenology of ecosystems. We found that the maximum photosynthetic rate was the most important factor for the IAV in gross primary productivity (GPP), which was mainly induced by the variation in vapour pressure deficit. For ecosystem respiration (RE), the most important drivers were GPP and the reference respiratory rate. The biome type regulated the direct and indirect paths, with distinctive differences between forests and non-forests, evergreen needleleaf forests and deciduous broadleaf forests, and between grasslands and croplands. Different paths were also found among wet, moist and dry ecosystems. However, the climatic variables can only partly explain the IAV in physiological parameters, suggesting that the latter may also result from other biotic and disturbance factors. In addition, the climatic variables related to NEE were not necessarily the same as those related to GPP and RE, indicating the emerging difficulty encountered when studying the IAV in NEE. Overall, our results highlight the contribution of certain physiological parameters to the IAV in C fluxes and the importance of biome type and multi-year water conditions, which should receive more attention in future experimental and modelling research. Keywords: net ecosystem exchange, interannual variability, climatic variations, physiological parameters, direct and indirect effects, relative importance (Published: 2 August 2016) Citation: Tellus B 2016, 68, 30575, http://dx.doi.org/10.3402/tellusb.v68.30575

Published
2016
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20. Precision Gas Sampling (PGS) Validation2011-2014 Final Campaign Report

Author

M. S. Tom, D. Billesbach, S. C. Biraud, and M. L. Fischer

Subjects
Atmospheric Radiation Measurement Climate Research Facility, Hydrology, Extreme weather, Geography, Bioenergy, Agriculture, business.industry, Latent heat, Eddy covariance, Tornado, Sensible heat, business
Abstract

In this field campaign, we used eddy covariance towers to quantify carbon, water, and energy fluxes from a pasture and a wheat field that were converted to switchgrass. The U.S. Department of Energy is investing in switchgrass as a cellulosic bioenergy crop, but there is little data available that could be used to develop or test land surface model representations of the crop. This campaign was a collaboration between Lawrence Berkeley National Laboratory and the U.S. Department of Agriculture Agricultural Research Service. Unfortunately, in 2011, Oklahoma had one of the most severe droughts on record, and the crop in one of the switchgrass fields experienced almost complete die-off. The crop was replanted, but subsequent drought conditions prevented its establishment. Then, in April 2012, a large tornado demolished the instruments at our site in Woodward, Oklahoma. These two events meant that we have some interesting data on land response to extreme weather; however, we were not able to collect continuous data for annual sums as originally intended. We did observe that, because of the drought, the net ecosystem exchange of CO2 was much lower in 2011 than in 2010. Concomitantly, sensible heat fluxes increased and latent heat fluxes decreased. These conditionsmore » would have large consequences for land surface forcing of convection. Data from all years were submitted to the Atmospheric Radiation Measurement Climate Research Facility Data Archive, and the sites were registered in AmeriFlux.« less

Published
2016
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21. Biotic and climatic controls on interannual variability in carbon fluxes across terrestrial ecosystems

Author

Margaret S. Torn, Andrej Varlagin, Xuhui Zhou, Walter C. Oechel, Rosvel Bracho, Peili Shi, Yiqi Luo, Thomas Kolb, M. L. Fischer, Peter D. Blanken, Huimin Wang, Shijie Han, David P. Billesbach, Andrew E. Suyker, Yingnian Li, Krisztina Pintér, Jiquan Chen, Junhua Yan, Zoltán Nagy, Mika Aurela, Bo Li, Guirui Yu, Junhui Zhang, Shuli Niu, Junjiong Shao, Yuling Fu, Yongtao He, and Lianhong Gu

Subjects
Atmospheric Science, Global and Planetary Change, Agricultural and Veterinary Sciences, Ecology, Biotic effect, Northern Hemisphere, Relative importance, Climate change, Forestry, Biological Sciences, Photosynthesis, Arid, Climate Action, Water balance, Interannual variability, Climatic stress, Deciduous, Earth Sciences, Environmental science, Meteorology & Atmospheric Sciences, Terrestrial ecosystem, Ecosystem, Net ecosystem exchange, Climatic effect, Agronomy and Crop Science
Abstract

Interannual variability (IAV, represented by standard deviation) in net ecosystem exchange of CO2 (NEE) is mainly driven by climatic drivers and biotic variations (i.e., the changes in photosynthetic and respiratory responses to climate), the effects of which are referred to as climatic (CE) and biotic effects (BE), respectively. Evaluating the relative contributions of CE and BE to the IAV in carbon (C) fluxes and understanding their controlling mechanisms are critical in projecting ecosystem changes in the future climate. In this study, we applied statistical methods with flux data from 65 sites located in the Northern Hemisphere to address this issue. Our results showed that the relative contribution of BE (CnBE) and CE (CnCE) to the IAV in NEE was 57%+/- 14% and 43%+/- 14%, respectively. The discrepancy in the CnBE among sites could be largely explained by water balance index (WBI). Across water-stressed ecosystems, the CnBE decreased with increasing aridity (slope =0.18%mm(-1)). In addition, the CnBE tended to increase and the uncertainty reduced as timespan of available data increased from 5 to 15 years. Inter-site variation of the IAV in NEE mainly resulted from the IAV in BE (72%) compared to that in CE (37%). Interestingly, positive correlations between BE and CE occurred in grasslands and dry ecosystems (r> 0.45, P< 0.05) but not in other ecosystems. These results highlighted the importance of BE in determining the IAV in NEE and the ability of ecosystems to regulate C fluxes under climate change might decline when the ecosystems experience more severe water stress in the future. (C) 2015 Elsevier B.V. All rights reserved.

Published
2015
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24. A measurement of the spectrum of the cosmic background radiation from 1 to 3 millimeter wavelength

Author

Paul L. Richards, M. L. Fischer, Thomas Timusk, J. B. Peterson, and G. M. Bernstein

Subjects
Physics, Wavelength, Brightness, Space and Planetary Science, Brightness temperature, Cosmic background radiation, Astronomy and Astrophysics, Black-body radiation, Millimeter, Spectral bands, Astrophysics, Background radiation
Abstract

The brightness temperature of the sky is measured in five bands from 1 to 3 mm using apparatus related to that of Woody and Richards (1981) and Peterson et al. (1985). Examination of the data reveals the presence of two previously unknown systematic effects which limit the accuracy of the measurements. Similar systematic effects are most likely present in the data obtained previously with this apparatus. Upper limits to the temperature of the cosmic background radiation are set in four bands; the most stringent is T(CBR) less than 2.88 K at 1.1 mm (95 percent CL).

Published
1990
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25. Changes in apolipoprotein and lipids in patients after surgery

Author

C L, Malmendier, J P, Amerijckx, B E, Bihain, and M L, Fischer

Subjects
Adult, Male, Parenteral Nutrition, Apolipoprotein A-I, Cholesterol, HDL, Middle Aged, Lipids, Surgical Procedures, Operative, Humans, Female, Postoperative Period, Apolipoprotein A-II, Apolipoproteins A, Aged
Abstract

Plasma levels of apoproteins A-I, A-II and B and apoprotein/lipid ratios were determined in 43 patients (14 male and 29 female) on the second to the sixth day after gastrointestinal surgery. During this period, all the patients received i. v. 5% dextrose solutions only. Apoprotein levels (A-I, A-II and B), total cholesterol, HDL-cholesterol and phospholipid were significantly decreased after surgery but there was no sex differences. Patients undergoing major surgery showed much lower values than the ones undergoing minor surgery. Both the extent of the trauma and the caloric restriction resulting from sole carbohydrate intravenous feeding may be responsible for these changes. Decreased hepatic synthesis combined to a lack of intestinal supply might result in apo A-I and A-II reduction. Repeated determinations of apoprotein levels are proposed as simple means of follow-up for evaluating the degree of recovery of patients undergoing gastrointestinal surgery.

Published
1985

27. Anisotropy of the diffuse background at millimeter wavelengths

Author

Thomas Timusk, M. L. Fischer, Paul L. Richards, J. B. Peterson, and G. M. Bernstein

Subjects
Physics, Wavelength, Space and Planetary Science, Isotropy, Cosmic background radiation, Dipole anisotropy, Astronomy and Astrophysics, Millimeter, Astrophysics, Anisotropy, Astronomical spectroscopy, Background radiation
Abstract

The anisotropy of the diffuse background radiation has been measured with a 10-deg FWHM beam in a broad spectral band from 0.6 to 4.0 mm. A dipole anisotropy is detected with magnitude consistent with previous measurements; the present data may, however, be contaminated by atmospheric emission. Upper limits are set to fluctuations at higher-order multipoles. The most stringent limit is at l = 4, where a 95-percent confidence-level limit of less than 0.00025 is set. The observed level of isotropy sharply constrains the possibility of local astronomical origin for the submillimeter excess.

Published
1989
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28. Reflective ‘cool’ roofs under aerosol-burdened skies: radiative benefits across selected Indian cities

Author

D E Millstein and M L Fischer

Subjects
cool roof, mitigation, radiative transfer, aerosols, Environmental technology. Sanitary engineering, TD1-1066, Environmental sciences, GE1-350, Science, Physics, QC1-999
Abstract

The use of reflective surfaces offers one low-cost solution for reducing solar loading to urban environments and the Earth that should be considered as part of sustainable urban design. Here, we characterize the radiative benefits, i.e. the additional shortwave radiation leaving the atmosphere, from the installation of highly reflective ‘cool’ roofs in urban areas in India that face relatively large local aerosol burdens. We use a previously tested column radiative transfer model to estimate the energy per unit area reflected to space from increasing the surface albedo at six cities within India. The model is used to characterize radiative transfer each day over five years (2008–2012) based on mid-day satellite retrievals of MODIS aerosol depth, cloud water path, and average surface albedo and MERRA atmospheric profiles of temperature and composition. Compared against ten months of field observations in two cities, the model derived incoming surface shortwave radiation estimates relative to observations show small biases (0.5% and −2.6%, at Pantnagar and Nainital, respectively). Despite the high levels of local aerosols we found cool roofs provided significant radiative benefits at all locations. Averaged over the five year period we found that increasing the albedo of 1 m ^2 of roof area by 0.5 would reflect to space 0.9–1.2 kWh daily from 08:30–15:30 LST, depending on location. This is equivalent to a constant forcing of 37–50 W m ^−2 (equivalent to reducing CO _2 emissions by 74 to 101 kg CO _2 m ^−2 roof area). Last, we identify a co-benefit of improving air quality, in that removing aerosols from the atmosphere could increase the radiative benefits from cool roofs by 23–74%, with the largest potential increase found at Delhi and the smallest change found at Nainital.

Published
2014
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