Ice nucleating particles measured during the laboratory and field intercomparisons FIN-2 and FIN-3 by the diffusion chamber FRIDGE

NASA Astrophysics Data System (ADS)

Weber, Daniel; Schrod, Jann; Curtius, Joachim; Haunold, Werner; Thomson, Erik; Bingemer, Heinz

2016-04-01

The measurement of atmospheric ice nucleating particles (INP) is still challenging. In the absence of easily applicable INP standards the intercomparison of different methods during collaborative laboratory and field workshops is a valuable tool that can shine light on the performance of individual methods for the measurement of INP [1]. FIN-2 was conducted in March 2015 at the AIDA facility in Karlsruhe as an intercomparison of mobile instruments for measuring INP [2]. FIN-3 was a field campaign at the Desert Research Institutes Storm Peak Laboratory in Colorado in September 2015 [3]. The FRankfurt Ice nucleation Deposition freezinG Experiment (FRIDGE) participated in both experiments. FRIDGE measures ice nucleating particles by electrostatic precipitation of aerosol particles onto Si-wafers in a collection unit, followed by activation, growth, and optical detection of ice crystals on the substrate in an isostatic diffusion chamber [4,5]. We will present and discuss results of our measurements of deposition/condensation INP and of immersion INP with FRIDGE during FIN-2 and FIN-3. Acknowledgements: The valuable contributions of the FIN organizers and their institutions, and of the FIN Workshop Science team are gratefully acknowledged. Our work was supported by Deutsche Forschungsgemeinschaft (DFG) under the Research Unit FOR 1525 (INUIT) and the EU FP7-ENV- 2013 BACCHUS project under Grant Agreement 603445.

The First SIMBIOS Radiometric Intercomparison (SIMRIC-1), April-September 2001

NASA Technical Reports Server (NTRS)

Meister, Gerhard; Abel, Peter; McClain, Charles; Barnes, Robert; Fargion, Giulietta; Cooper, John; Davis, Curtiss; Korwan, Daniel; Godin, Mike; Maffione, Robert

2002-01-01

This report describes the first SIMBIOS (Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies) Radiometric Intercomparison (SIMRIC-1). The purpose of the SIMRIC-1 is to ensure a common radiometric scale of the calibration facilities that are engaged in calibrating in situ radiometers used for ocean color related research and to document the calibration procedures and protocols. SIMBIOS staff visited the seven participating laboratories for at least two days each. The SeaWiFS Transfer Radiometer SXR-II measured the calibration radiances produced in the laboratories. The measured radiances were compared with the radiances expected by the laboratories. Typically, the measured radiances were higher than the expected radiances by 0 to 2%. This level of agreement is satisfactory. Several issues were identified, where the calibration protocols need to be improved, especially the reflectance calibration of the reference plaques and the distance correction when using the irradiance standards at distances greater than the 50 cm. The responsivity of the SXR-II changed between 0.3% (channel 6) and 1.6% (channel 2) from December 2000 to December 2001. Monitoring the SXR-II with a portable light source showed a linear drift of the calibration, except for channel 1, where a 2% drop occurred in summer.

An intercomparison study of analytical methods used for quantification of levoglucosan in ambient aerosol filter samples

NASA Astrophysics Data System (ADS)

Yttri, K. E.; Schnelle-Kreiss, J.; Maenhaut, W.; Alves, C.; Bossi, R.; Bjerke, A.; Claeys, M.; Dye, C.; Evtyugina, M.; García-Gacio, D.; Gülcin, A.; Hillamo, R.; Hoffer, A.; Hyder, M.; Iinuma, Y.; Jaffrezo, J.-L.; Kasper-Giebl, A.; Kiss, G.; López-Mahia, P. L.; Pio, C.; Piot, C.; Ramirez-Santa-Cruz, C.; Sciare, J.; Teinilä, K.; Vermeylen, R.; Vicente, A.; Zimmermann, R.

2014-07-01

The monosaccharide anhydrides (MAs) levoglucosan, galactosan and mannosan are products of incomplete combustion and pyrolysis of cellulose and hemicelluloses, and are found to be major constituents of biomass burning aerosol particles. Hence, ambient aerosol particle concentrations of levoglucosan are commonly used to study the influence of residential wood burning, agricultural waste burning and wild fire emissions on ambient air quality. A European-wide intercomparison on the analysis of the three monosaccharide anhydrides was conducted based on ambient aerosol quartz fiber filter samples collected at a Norwegian urban background site during winter. Thus, the samples' content of MAs is representative for biomass burning particles originating from residential wood burning. The purpose of the intercomparison was to examine the comparability of the great diversity of analytical methods used for analysis of levoglucosan, mannosan and galactosan in ambient aerosol filter samples. Thirteen laboratories participated, of which three applied High-Performance Anion-Exchange Chromatography (HPAEC), four used High-Performance Liquid Chromatography (HPLC) or Ultra-Performance Liquid Chromatography (UPLC), and six resorted to Gas Chromatography (GC). The analytical methods used were of such diversity that they should be considered as thirteen different analytical methods. All of the thirteen laboratories reported levels of levoglucosan, whereas nine reported data for mannosan and/or galactosan. Eight of the thirteen laboratories reported levels for all three isomers. The accuracy for levoglucosan, presented as the mean percentage error (PE) for each participating laboratory, varied from -63 to 23%; however, for 62% of the laboratories the mean PE was within ±10%, and for 85% the mean PE was within ±20%. For mannosan, the corresponding range was -60 to 69%, but as for levoglucosan, the range was substantially smaller for a subselection of the laboratories; i.e., for 33% of

An intercomparison study of analytical methods used for quantification of levoglucosan in ambient aerosol filter samples

NASA Astrophysics Data System (ADS)

Yttri, K. E.; Schnelle-Kreis, J.; Maenhaut, W.; Abbaszade, G.; Alves, C.; Bjerke, A.; Bonnier, N.; Bossi, R.; Claeys, M.; Dye, C.; Evtyugina, M.; García-Gacio, D.; Hillamo, R.; Hoffer, A.; Hyder, M.; Iinuma, Y.; Jaffrezo, J.-L.; Kasper-Giebl, A.; Kiss, G.; López-Mahia, P. L.; Pio, C.; Piot, C.; Ramirez-Santa-Cruz, C.; Sciare, J.; Teinilä, K.; Vermeylen, R.; Vicente, A.; Zimmermann, R.

2015-01-01

The monosaccharide anhydrides (MAs) levoglucosan, galactosan and mannosan are products of incomplete combustion and pyrolysis of cellulose and hemicelluloses, and are found to be major constituents of biomass burning (BB) aerosol particles. Hence, ambient aerosol particle concentrations of levoglucosan are commonly used to study the influence of residential wood burning, agricultural waste burning and wildfire emissions on ambient air quality. A European-wide intercomparison on the analysis of the three monosaccharide anhydrides was conducted based on ambient aerosol quartz fiber filter samples collected at a Norwegian urban background site during winter. Thus, the samples' content of MAs is representative for BB particles originating from residential wood burning. The purpose of the intercomparison was to examine the comparability of the great diversity of analytical methods used for analysis of levoglucosan, mannosan and galactosan in ambient aerosol filter samples. Thirteen laboratories participated, of which three applied high-performance anion-exchange chromatography (HPAEC), four used high-performance liquid chromatography (HPLC) or ultra-performance liquid chromatography (UPLC) and six resorted to gas chromatography (GC). The analytical methods used were of such diversity that they should be considered as thirteen different analytical methods. All of the thirteen laboratories reported levels of levoglucosan, whereas nine reported data for mannosan and/or galactosan. Eight of the thirteen laboratories reported levels for all three isomers. The accuracy for levoglucosan, presented as the mean percentage error (PE) for each participating laboratory, varied from -63 to 20%; however, for 62% of the laboratories the mean PE was within ±10%, and for 85% the mean PE was within ±20%. For mannosan, the corresponding range was -60 to 69%, but as for levoglucosan, the range was substantially smaller for a subselection of the laboratories; i.e. for 33% of the

1993 Intercomparison of Photometric Units Maintained at NIST (USA) and PTB (Germany)

PubMed Central

Ohno, Yoshihiro; Sauter, Georg

1995-01-01

A bilateral intercomparison of photometric units between NIST, USA and PTB, Germany has been conducted to update the knowledge of the relationship between the photometric units disseminated in each country. The luminous intensity unit (cd) and the luminous flux unit (lm) maintained at both laboratories are compared by circulating transfer standard lamps. Also, the photometric responsivity sv is compared by circulating a V(λ)-corrected detector with a built-in current-to-voltage converter. The results show that the difference of luminous intensity unit between NIST and PTB, (PTB-NIST)/NIST, is 0.2 % with a relative expanded uncertainty (coverage factor k = 2) of 0.24 %. The difference is reduced significantly from that at the 1985 CCPR intercomparison (0.9 %). The difference in luminous flux unit, (PTB – NIST)/NIST, is found to be 1.5 % with a relative expanded uncertainty (coverage factor k =2) of 0.15 %. The difference remained nearly the same as that at the 1985 intercomparison (1.6 %). These results agree with what is predicted from the history of maintaining the units at each laboratory. PMID:29151737

The April 1994 and October 1994 radon intercomparisons at EML

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisenne, I.M.; George, A.C.; Perry, P.M.

1995-10-01

Quality assurance/quality control (QA/QC) are the backbone of many commercial and research processes and programs. QA/QC research tests the state of a functioning system, be it the production of manufactured goods or the ability to make accurate and precise measurements. The quality of the radon measurements in the US have been tested under controlled conditions in semi-annual radon gas intercomparison exercises sponsored by the Environmental Measurements Laboratory (EML) since 1981. The two Calendar Year 1994 radon gas intercomparison exercises were conducted in the EML exposure chamber. Thirty-two groups including US Federal facilities, USDOE contractors, national and state laboratories, universities andmore » foreign institutions participated in these exercises. The majority of the participant`s results were within {+-}10% of the EML value at radon concentrations of 570 and 945 Bq m{sup {minus}3}.« less

The Second SIMBIOS Radiometric Intercomparison (SIMRIC-2), March-November 2002. Volume 2

NASA Technical Reports Server (NTRS)

Meister, Gerhard; Abel, Peter; Carder, Kendall; Chapin, Albert; Clark, Dennis; Cooper, John; Davis, Curtis; English, David; Fargion, Giulietta; Feinholz, Michael;

Agricultural model intercomparison and improvement project: Overview of model intercomparisons

USDA-ARS?s Scientific Manuscript database

Improvement of crop simulation models to better estimate growth and yield is one of the objectives of the Agricultural Model Intercomparison and Improvement Project (AgMIP). The overall goal of AgMIP is to provide an assessment of crop model through rigorous intercomparisons and evaluate future clim...

THE NORTH AMERICAN MERCURY MODEL INTER-COMPARISON STUDY (NAMMIS)

EPA Science Inventory

This paper describes the North American Mercury Model Inter-comparison Study (NAMMIS). The NAMMIS is an effort to apply atmospheric Hg models in a tightly constrained testing environment with a focus on North America. With each model using the same input data sets for initial co...

The April 1992 and November 1992 radon intercomparisons at EML

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisenne, I.M.; George, A.C.; Perry, P.M.

1993-07-01

The Environmental Measurements Laboratory hosted two intercomparison exercises in Calendar Year 1992. Thirty-two groups, including US federal facilities, US Department of Energy`s Office of Health and Environmental Research contractors, national and state laboratories, and universities and foreign institutions, participated in these exercises. The majority of the participants` results were within {plus_minus}10% of the EML value at radon concentrations of 2075 and 1650 Bq m{sup {minus}3}.

Stratospheric Ozone Intercomparison Campaign (STOIC) 1989: Overview

NASA Technical Reports Server (NTRS)

Margitan, J. J.; Barnes, R. A.; Brothers, G. B.; Butler, J.; Burris, J.; Connor, B. J.; Ferrare, R. A.; Kerr, J. B.; Komhyr, W. D.; McCormick, M. P.;

Comprehensive Australasian multicentre dosimetric intercomparison: issues, logistics and recommendations.

PubMed

Ebert, M A; Harrison, K M; Cornes, D; Howlett, S J; Joseph, D J; Kron, T; Hamilton, C S; Denham, J W

2009-02-01

The present paper describes the logistics of the 2004-2008 Australasian Level III Dosimetry Intercomparison. Dosimetric intercomparisons (or 'audits') can be used in radiotherapy to evaluate the accuracy and quality of radiation delivery. An intercomparison was undertaken in New Zealand and Australia to evaluate the feasibility and logistics of ongoing dosimetric intercomparisons that evaluate all steps in the radiotherapy treatment process, known as a 'Level III' intercomparison. The study commenced in 2002 with the establishment of a study team, definition of the study protocol, acquisition of appropriate equipment and recruitment of participating radiotherapy centres. Measurements were undertaken between October 2004 and March 2008, and included collation of data on time, costs and logistics of the study. Forty independent Australian and New Zealand radiotherapy centres agreed to participate. Measurement visits were made to 37 of these centres. Data is presented on the costs of the study and the level of support required. The study involved the participation of 16 staff at the study centre who invested over 4000 hours in the study, and of over 200 professionals at participating centres. Recommendations are provided for future phantom-based intercomparisons. It is hoped that the present paper will be of benefit to any centres or groups contemplating similar activities by identifying the processes involved in establishing the study, the potential hazards and pitfalls, and expected resource requirements.

Summary findings of the fourth international radiocarbon intercomparison (FIRI)(1998-2001)

NASA Astrophysics Data System (ADS)

Boaretto, Elisabetta; Bryant, Charlotte; Carmi, Israel; Cook, Gordon; Gulliksen, Steinar; Harkness, Doug; Heinemeier, Jan; McClure, John; McGee, Edward; Naysmith, Philip; Possnert, Goran; Scott, Marian; van der Plicht, Hans; van Strydonck, Mark

2002-10-01

Interlaboratory comparisons have been widely used in applied radiocarbon science. These are an important part of ongoing quality assurance (QA) programmes, which are vital to the appropriate interpretation of the evidence provided by the 14C record in Quaternary applications (including climate change and environmental reconstruction). International comparisons of laboratory performance are an essential component of the quality assurance process in radiocarbon dating. If the user community is to have confidence in radiocarbon results, it needs to be assured that laboratories world wide are producing measurements that are reliable and in accordance with good practice. The findings from the most recent (completed in 2001) and extensive (more than 90 participating laboratories) radiocarbon intercomparison (FIRI) are reported here. This study was designed (i) to assess comparability, or otherwise, of the results from different laboratories and (ii) to quantify the extent and possible causes of any interlaboratory variation. The results demonstrate that there are no significant differences amongst the main measurement techniques (gas proportional counting, liquid scintillation counting and accelerator mass spectrometry (AMS)) but there is evidence of small laboratory offsets relative to known age samples for some laboratories. There is also evidence in some cases of underestimation of measurement precision. Approximately 10% of all results were classified as extreme (outliers) and these results were generated by 14% of the laboratories. Overall, the evidence supports the fact that radiocarbon laboratories are generally accurate and precise but that, notwithstanding internal QA procedures, some problems still occur, which can best be detected by participation in independent intercomparisons such as FIRI, where the results allow individual laboratories to assess their performance and to take remedial measures where necessary. The results from FIRI are significant in that

EURADOS intercomparison on emergency radiobioassay.

PubMed

Li, Chunsheng; Battisti, Paolo; Berard, Philippe; Cazoulat, Alain; Cuellar, Antonio; Cruz-Suarez, Rodolfo; Dai, Xiongxin; Giardina, Isabella; Hammond, Derek; Hernandez, Carolina; Kiser, Stephen; Ko, Raymond; Kramer-Tremblay, Sheila; Lecompte, Yannick; Navarro, Eva; Navas, Cristina; Sadi, Baki; Sierra, Inmaculada; Verrezen, Freddy; Lopez, Maria A

2015-12-01

Nine laboratories participated in an intercomparison exercise organised by the European Radiation Dosimetry Group (EURADOS) for emergency radiobioassay involving four high-risk radionuclides ((239)Pu, (241)Am, (90)Sr and (226)Ra). Diverse methods of analysis were used by the participating laboratories for the in vitro determination of each of the four radionuclides in urine samples. Almost all the methods used are sensitive enough to meet the requirements for emergency radiobioassay derived for this project in reference to the Clinical Decision Guide introduced by the NCRP. Results from most of the methods meet the requirements of ISO 28218 on accuracy in terms of relative bias and relative precision. However, some technical gaps have been identified. For example, some laboratories do not have the ability to assay samples containing (226)Ra, and sample turnaround time would be expected to be much shorter than that reported by many laboratories, as timely results for internal contamination and early decisions on medical intervention are highly desired. Participating laboratories are expected to learn from each other on the methods used to improve the interoperability among these laboratories. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inter-comparison of three-dimensional models of volcanic plumes

USGS Publications Warehouse

Suzuki, Yujiro; Costa, Antonio; Cerminara, Matteo; Esposti Ongaro, Tomaso; Herzog, Michael; Van Eaton, Alexa; Denby, Leif

2016-01-01

We performed an inter-comparison study of three-dimensional models of volcanic plumes. A set of common volcanological input parameters and meteorological conditions were provided for two kinds of eruptions, representing a weak and a strong eruption column. From the different models, we compared the maximum plume height, neutral buoyancy level (where plume density equals that of the atmosphere), and level of maximum radial spreading of the umbrella cloud. We also compared the vertical profiles of eruption column properties, integrated across cross-sections of the plume (integral variables). Although the models use different numerical procedures and treatments of subgrid turbulence and particle dynamics, the inter-comparison shows qualitatively consistent results. In the weak plume case (mass eruption rate 1.5 × 106 kg s− 1), the vertical profiles of plume properties (e.g., vertical velocity, temperature) are similar among models, especially in the buoyant plume region. Variability among the simulated maximum heights is ~ 20%, whereas neutral buoyancy level and level of maximum radial spreading vary by ~ 10%. Time-averaging of the three-dimensional (3D) flow fields indicates an effective entrainment coefficient around 0.1 in the buoyant plume region, with much lower values in the jet region, which is consistent with findings of small-scale laboratory experiments. On the other hand, the strong plume case (mass eruption rate 1.5 × 109 kg s− 1) shows greater variability in the vertical plume profiles predicted by the different models. Our analysis suggests that the unstable flow dynamics in the strong plume enhances differences in the formulation and numerical solution of the models. This is especially evident in the overshooting top of the plume, which extends a significant portion (~ 1/8) of the maximum plume height. Nonetheless, overall variability in the spreading level and neutral buoyancy level is ~ 20%, whereas that of maximum height is ~ 10

The agricultural model intercomparison and improvement project (AgMIP): Protocols and pilot studies

USDA-ARS?s Scientific Manuscript database

The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a distributed climate-scenario simulation research activity for historical period model intercomparison and future climate change conditions with participation of multiple crop and agricultural economic model groups around the...

BIPM project: Intercomparison of water triple-point cells

NASA Astrophysics Data System (ADS)

Chattle, M. V.; Butler, J.

1994-12-01

The paper presents the results of an intercomparison between 3 triple point of water cells circulated by the Bureau International des Poids et Measures (BIPM), and a cell which is one of those used as a reference cell at the National Physical Laboratory (NPL). All 4 cells were prepared, stored and measured in the manner normally adopted at NPL. The results of the intercomparison show that over the course of about 6 weeks the temperatures of the 3 circulated cells generally agreed within 0.20 mK, with a maximum difference of 0.27(7) mK. Over the same period, the total variations of temperature measured in the 3 individual cells were 0.04 mK, 0.08 mK and 0.18 mK, respectively; the NPL cell varied by 0.10 mK. Gallium point measurements made over a similar period confirmed that these differences were partly due to small drifts in the thermometer resistance or in the measuring system.

International Intercomparison of Regular Transmittance Scales

NASA Astrophysics Data System (ADS)

Eckerle, K. L.; Sutter, E.; Freeman, G. H. C.; Andor, G.; Fillinger, L.

1990-01-01

An intercomparison of the regular spectral transmittance scales of NIST, Gaithersburg, MD (USA); PTB, Braunschweig (FRG); NPL, Teddington, Middlesex (UK); and OMH, Budapest (H) was accomplished using three sets of neutral glass filters with transmittances ranging from approximately 0.92 to 0.001. The difference between the results from the reference spectrophotometers of the laboratories was generally smaller than the total uncertainty of the interchange. The relative total uncertainty ranges from 0.05% to 0.75% for transmittances from 0.92 to 0.001. The sample-induced error was large - contributing 40% or more of the total except in a few cases.

Dosimetry audits and intercomparisons in radiotherapy: A Malaysian profile

NASA Astrophysics Data System (ADS)

M. Noor, Noramaliza; Nisbet, A.; Hussein, M.; Chu S, Sarene; Kadni, T.; Abdullah, N.; Bradley, D. A.

2017-11-01

Quality audits and intercomparisons are important in ensuring control of processes in any system of endeavour. Present interest is in control of dosimetry in teletherapy, there being a need to assess the extent to which there is consistent radiation dose delivery to the patient. In this study we review significant factors that impact upon radiotherapy dosimetry, focusing upon the example situation of radiotherapy delivery in Malaysia, examining existing literature in support of such efforts. A number of recommendations are made to provide for increased quality assurance and control. In addition to this study, the first level of intercomparison audit i.e. measuring beam output under reference conditions at eight selected Malaysian radiotherapy centres is checked; use being made of 9 μm core diameter Ge-doped silica fibres (Ge-9 μm). The results of Malaysian Secondary Standard Dosimetry Laboratory (SSDL) participation in the IAEA/WHO TLD postal dose audit services during the period between 2011 and 2015 will also been discussed. In conclusion, following review of the development of dosimetry audits and the conduct of one such exercise in Malaysia, it is apparent that regular periodic radiotherapy audits and intercomparison programmes should be strongly supported and implemented worldwide. The programmes to-date demonstrate these to be a good indicator of errors and of consistency between centres. A total of ei+ght beams have been checked in eight Malaysian radiotherapy centres. One out of the eight beams checked produced an unacceptable deviation; this was found to be due to unfamiliarity with the irradiation procedures. Prior to a repeat measurement, the mean ratio of measured to quoted dose was found to be 0.99 with standard deviation of 3%. Subsequent to the repeat measurement, the mean distribution was 1.00, and the standard deviation was 1.3%.

A Bootstrap Algorithm for Mixture Models and Interval Data in Inter-Comparisons

DTIC Science & Technology

2001-07-01

parametric bootstrap. The present algorithm will be applied to a thermometric inter-comparison, where data cannot be assumed to be normally distributed. 2 Data...experimental methods, used in each laboratory) often imply that the statistical assumptions are not satisfied, as for example in several thermometric ...triangular). Indeed, in thermometric experiments these three probabilistic models can represent several common stochastic variabilities for

Reproducibility in cyclostratigraphy: initiating an intercomparison project

NASA Astrophysics Data System (ADS)

Sinnesael, Matthias; De Vleeschouwer, David; Zeeden, Christian; Claeys, Philippe

2017-04-01

The study of astronomical climate forcing and the application of cyclostratigraphy have experienced a spectacular growth over the last decades. In the field of cyclostratigraphy a broad range in methodological approaches exist. However, comparative study between the different approaches is lacking. Different cases demand different approaches, but with the growing importance of the field, questions arise about reproducibility, uncertainties and standardization of results. The radioisotopic dating community, in particular, has done far-reaching efforts to improve reproducibility and intercomparison of radioisotopic dates and their errors. To satisfy this need in cyclostratigraphy, we initiate a comparable framework for the community. The aims are to investigate and quantify reproducibility of, and uncertainties related to cyclostratigraphic studies and to provide a platform to discuss the merits and pitfalls of different methodologies, and their applicabilities. With this poster, we ask the feedback from the community on how to design this comparative framework in a useful, meaningful and productive manner. In parallel, we would like to discuss how reproducibility should be tested and what uncertainties should stand for in cyclostratigraphy. On the other hand, we intend to trigger interest for a cyclostratigraphic intercomparison project. This intercomparison project would imply the analysis of artificial and genuine geological records by individual researchers. All participants would be free to determine their method of choice. However, a handful of criterions will be required for an outcome to be comparable. The different results would be compared (e.g. during a workshop or a special session), and the lessons learned from the comparison could potentially be reported in a review paper. The aim of an intercomparison project is not to rank the different methods according to their merits, but to get insight into which specific methods are most suitable for which

INTERCOMPARISON STUDY OF ATMOSPHERIC MERCURY MODELS: 1. COMPARISON OF MODELS WITH SHORT-TERM MEASUREMENTS

EPA Science Inventory

Five regional scale models with a horizontal domain covering the European continent and its surrounding seas, one hemispheric and one global scale model participated in an atmospheric mercury modelling intercomparison study. Model-predicted concentrations in ambient air were comp...

1989 Intercomparison of radon progeny measurement methods and equipment in North America

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scofield, P.; George, A.; Tu, Keng.

1990-03-01

At the 1989 {sup 222}Rn progeny intercomparison held at the Environmental Measurements Laboratory (EML), July 10--14, 1989, grab sampling and integrating/continuous {sup 222}Rn progeny methods were evaluated. Sixteen facilities participated in this intercomparison. Twelve facilities used {sup 222}Rn progeny grab sampling methods, and nine facilities used integrating/continuous instruments. Eighty-eight percent of the participants reported grab sample {sup 222}Rn progeny concentrations that were within 20% of the EML reference values. Good agreement between participant and EML grab-sample potential alpha energy concentrations (PAECs) was observed; 92% of the participants had PAECs within 20% of the EML values. For the integrating/continuous PAEC valuesmore » determined with integrating/continuous monitors, 89% of the participants were within 20% of the EML reference values. 9 refs., 3 figs., 4 tabs.« less

Intercomparison of analytical methods for arsenic speciation in human urine.

PubMed Central

Crecelius, E; Yager, J

1997-01-01

An intercomparison exercise was conducted for the quantification of arsenic species in spiked human urine. The primary objective of the exercise was to determine the variance among laboratories in the analysis of arsenic species such as inorganic As (As+3 and As+5), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Laboratories that participated had previous experience with arsenic speciation analysis. The results of this interlaboratory comparison are encouraging. There is relatively good agreement on the concentrations of these arsenic species in urine at concentrations that are relevant to research on the metabolism of arsenic in humans and other mammals. Both the accuracy and precision are relatively poor for arsenic concentrations of less than about 5 micrograms/l. PMID:9288500

Intercomparison of analytical methods for arsenic speciation in human urine.

PubMed

Crecelius, E; Yager, J

1997-06-01

An intercomparison exercise was conducted for the quantification of arsenic species in spiked human urine. The primary objective of the exercise was to determine the variance among laboratories in the analysis of arsenic species such as inorganic As (As+3 and As+5), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Laboratories that participated had previous experience with arsenic speciation analysis. The results of this interlaboratory comparison are encouraging. There is relatively good agreement on the concentrations of these arsenic species in urine at concentrations that are relevant to research on the metabolism of arsenic in humans and other mammals. Both the accuracy and precision are relatively poor for arsenic concentrations of less than about 5 micrograms/l.

Intercomparison of ground-based NO y measurement techniques

NASA Astrophysics Data System (ADS)

Williams, E. J.; Baumann, K.; Roberts, J. M.; Bertman, S. B.; Norton, R. B.; Fehsenfeld, F. C.; Springston, S. R.; Nunnermacker, L. J.; Newman, L.; Olszyna, K.; Meagher, J.; Hartsell, B.; Edgerton, E.; Pearson, J. R.; Rodgers, M. O.

1998-09-01

An informal intercomparison of NOy measurement techniques was conducted from June 13 to July 22, 1994, at a site in Hendersonville, Tennessee, near Nashville. The intercomparison involved five research institutions: Brookhaven National Laboratory, Environmental Science and Engineering, Georgia Institute of Technology, NOAA/Aeronomy Laboratory, and Tennessee Valley Authority. The NOy measurement techniques relied on the reduction of NOy species to NO followed by detection of NO using O3-chemiluminescence. The NOy methods used either the Au-catalyzed conversion of NOy to NO in the presence of CO or H2 or the reduction of NOy to NO on a heated molybdenum oxide surface. Other measurements included O3, NOx, PAN and other organic peroxycarboxylic nitric anhydrides, HNO3 and particulate nitrate, and meteorological parameters. The intercomparison consisted of six weeks of ambient air sampling with instruments and inlet systems normally used by the groups for field measurements. In addition, periodic challenges to the instruments (spike tests) were conducted with known levels of NO, NO2, NPN, HNO3 and NH3. The NOy levels were typically large and highly variable, ranging from 2 ppbv to about 100 ppbv, and for much of the time was composed mostly of NOx from nearby sources. The spike tests results and ambient air results were consistent only when NOx was a substantial fraction of NOy. Inconsistency with ambient air data and the other spike test results is largely attributed to imprecision in the spike results due to the high and variable NOy background. For the ambient air data, a high degree of correlation was found with the different data sets. Of the seven NOy instrument/converters deployed at the site, two (one Au and one Mo) showed evidence of some loss of conversion efficiency. This occurred when the more oxidized NOy species (e.g., HNO3) were in relatively high abundance, as shown by analysis of one period of intense photochemical activity. For five of the instruments

A Compendium on the NIST Radionuclidic Assays of the Massic Activity of 63Ni and 55Fe Solutions Used for an International Intercomparison of Liquid Scintillation Spectrometry Techniques

PubMed Central

Collé, R.; Zimmerman, B. E.

1997-01-01

The National Institute of Standards and Technology recently participated in an international measurement intercomparison for 63Ni and 55Fe, which was conducted amongst principal national radionuclidic metrology laboratories. The intercomparison was sponsored by EUROMET, and was primarily intended to evaluate the capabilities of liquid scintillation (LS) spectrometry techniques for standardizing nuclides that decay by low-energy β-emission (like 63Ni) and by low-Z (atomic number) electron capture (like 55Fe). The intercomparison findings exhibit a very good agreement for 63Ni amongst the various participating laboratories, including that for NIST, which suggests that the presently invoked LS methodologies are very capable of providing internationally-compatible standardizations for low-energy β-emitters. The results for 55Fe are in considerably poorer agreement, and demonstrated the existence of several unresolved problems. It has thus become apparent that there is a need for the various international laboratories to conduct rigorous, systematic evaluations of their LS capabilities in assaying radionuclides that decay by low-Z electron capture. PMID:27805141

How reliable are efficiency measurements of perovskite solar cells? The first inter-comparison, between two accredited and eight non-accredited laboratories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunbar, Ricky B.; Duck, Benjamin C.; Moriarty, Tom E.

Perovskite materials have generated significant interest from academia and industry as a potential component in next-generation, high-efficiency, low-cost, photovoltaic (PV) devices. The record efficiency reported for perovskite solar cells has risen rapidly, and is now more than 22%. However, due to their complex dynamic behaviour, the process of measuring the efficiency of perovskite solar cells appears to be much more complicated than for other technologies. It has long been acknowledged that this is likely to greatly reduce the reliability of reported efficiency measurements, but the quantitative extent to which this occurs has not been determined. To investigate this, we conductmore » the first major inter-comparison of this PV technology. The participants included two labs accredited for PV performance measurement (CSIRO and NREL) and eight PV research laboratories. We find that the inter-laboratory measurement variability can be almost ten times larger for a slowly responding perovskite cell than for a control silicon cell. We show that for such a cell, the choice of measurement method, far more so than measurement hardware, is the single-greatest cause for this undesirably large variability. We provide recommendations for identifying the most appropriate method for a given cell, depending on its stabilization and degradation behaviour. Moreover, the results of this study suggest that identifying a consensus technique for accurate and meaningful efficiency measurements of perovskite solar cells will lead to an immediate improvement in reliability. This, in turn, should assist device researchers to correctly evaluate promising new materials and fabrication methods, and further boost the development of this technology.« less

How reliable are efficiency measurements of perovskite solar cells? The first inter-comparison, between two accredited and eight non-accredited laboratories

DOE PAGES

Dunbar, Ricky B.; Duck, Benjamin C.; Moriarty, Tom E.; ...

2017-10-24

Perovskite materials have generated significant interest from academia and industry as a potential component in next-generation, high-efficiency, low-cost, photovoltaic (PV) devices. The record efficiency reported for perovskite solar cells has risen rapidly, and is now more than 22%. However, due to their complex dynamic behaviour, the process of measuring the efficiency of perovskite solar cells appears to be much more complicated than for other technologies. It has long been acknowledged that this is likely to greatly reduce the reliability of reported efficiency measurements, but the quantitative extent to which this occurs has not been determined. To investigate this, we conductmore » the first major inter-comparison of this PV technology. The participants included two labs accredited for PV performance measurement (CSIRO and NREL) and eight PV research laboratories. We find that the inter-laboratory measurement variability can be almost ten times larger for a slowly responding perovskite cell than for a control silicon cell. We show that for such a cell, the choice of measurement method, far more so than measurement hardware, is the single-greatest cause for this undesirably large variability. We provide recommendations for identifying the most appropriate method for a given cell, depending on its stabilization and degradation behaviour. Moreover, the results of this study suggest that identifying a consensus technique for accurate and meaningful efficiency measurements of perovskite solar cells will lead to an immediate improvement in reliability. This, in turn, should assist device researchers to correctly evaluate promising new materials and fabrication methods, and further boost the development of this technology.« less

The Program for climate Model diagnosis and Intercomparison: 20-th anniversary Symposium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Potter, Gerald L; Bader, David C; Riches, Michael

Twenty years ago, W. Lawrence (Larry) Gates approached the U.S. Department of Energy (DOE) Office of Energy Research (now the Office of Science) with a plan to coordinate the comparison and documentation of climate model differences. This effort would help improve our understanding of climate change through a systematic approach to model intercomparison. Early attempts at comparing results showed a surprisingly large range in control climate from such parameters as cloud cover, precipitation, and even atmospheric temperature. The DOE agreed to fund the effort at the Lawrence Livermore National Laboratory (LLNL), in part because of the existing computing environment andmore » because of a preexisting atmospheric science group that contained a wide variety of expertise. The project was named the Program for Climate Model Diagnosis and Intercomparison (PCMDI), and it has changed the international landscape of climate modeling over the past 20 years. In spring 2009 the DOE hosted a 1-day symposium to celebrate the twentieth anniversary of PCMDI and to honor its founder, Larry Gates. Through their personal experiences, the morning presenters painted an image of climate science in the 1970s and 1980s, that generated early support from the international community for model intercomparison, thereby bringing PCMDI into existence. Four talks covered Gates's early contributions to climate research at the University of California, Los Angeles (UCLA), the RAND Corporation, and Oregon State University through the founding of PCMDI to coordinate the Atmospheric Model Intercomparison Project (AMIP). The speakers were, in order of presentation, Warren Washington [National Center for Atmospheric Research (NCAR)], Kelly Redmond (Western Regional Climate Center), George Boer (Canadian Centre for Climate Modelling and Analysis), and Lennart Bengtsson [University of Reading, former director of the European Centre for Medium-Range Weather Forecasts (ECMWF)]. The afternoon session

Accuracy of tretyakov precipitation gauge: Result of wmo intercomparison

USGS Publications Warehouse

Yang, Daqing; Goodison, Barry E.; Metcalfe, John R.; Golubev, Valentin S.; Elomaa, Esko; Gunther, Thilo; Bates, Roy; Pangburn, Timothy; Hanson, Clayton L.; Emerson, Douglas G.; Copaciu, Voilete; Milkovic, Janja

1995-01-01

The Tretyakov non-recording precipitation gauge has been used historically as the official precipitation measurement instrument in the Russian (formerly the USSR) climatic and hydrological station network and in a number of other European countries. From 1986 to 1993, the accuracy and performance of this gauge were evaluated during the WMO Solid Precipitation Measurement Intercomparison at 11 stations in Canada, the USA, Russia, Germany, Finland, Romania and Croatia. The double fence intercomparison reference (DFIR) was the reference standard used at all the Intercomparison stations in the Intercomparison. The Intercomparison data collected at the different sites are compatible with respect to the catch ratio (measured/DFIR) for the same gauge, when compared using mean wind speed at the height of the gauge orifice during the observation period.The Intercomparison data for the Tretyakov gauge were compiled from measurements made at these WMO intercomparison sites. These data represent a variety of climates, terrains and exposures. The effects of environmental factors, such as wind speed, wind direction, type of precipitation and temperature, on gauge catch ratios were investigated. Wind speed was found to be the most important factor determining the gauge catch and air temperature had a secondary effect when precipitation was classified into snow, mixed and rain. The results of the analysis of gauge catch ratio versus wind speed and temperature on a daily time step are presented for various types of precipitation. Independent checks of the correction equations against the DFIR have been conducted at those Intercomparison stations and a good agreement (difference less than 10%) has been obtained. The use of such adjustment procedures should significantly improve the accuracy and homogeneity of gauge-measured precipitation data over large regions of the former USSR and central Europe.

International round-robin inter-comparison of dye-sensitized and crystalline silicon solar cells

NASA Astrophysics Data System (ADS)

Chen, Chia-Yuan; Ahn, Seung Kyu; Aoki, Dasiuke; Kokubo, Junichi; Yoon, Kyung Hoon; Saito, Hidenori; Lee, Kyung Sik; Magaino, Shinichi; Takagi, Katsuhiko; Lin, Ling-Chuan; Lee, Kun-Mu; Wu, Chun-Guey; Zhou, Hong; Igari, Sanekazu

2017-02-01

An international round-robin inter-comparison of the spectral responsivity (SR) and current-voltage (I-V) characteristics for dye-sensitized solar cells (DSCs) and crystalline silicon solar cells is reported for the first time. The crystalline silicon cells with various spectral responsivities were also calibrated by AIST to validate this round-robin activity. On the basis of the remarkable consistency in Pmax (within ±1.4% among participants) and Isc (within ±1.2% compared to the primary calibration of AIST) of the silicon specimens, the discrepancy in the SR and photovoltaic parameters of five DSCs among three national laboratories can be verified and diagnosed. Recommendations about sample packages, SR and I-V measurement methods as well as the inter-comparison protocol for improving the performance characterization of the mesoscopic DSCs are presented according to the consolidated data and the experience of the participants.

Emergency radiobioassay preparedness exercises through the NIST radiochemistry intercomparison program.

PubMed

Nour, Svetlana; LaRosa, Jerry; Inn, Kenneth G W

2011-08-01

The present challenge for the international emergency radiobioassay community is to analyze contaminated samples rapidly while maintaining high quality results. The National Institute of Standards and Technology (NIST) runs a radiobioassay measurement traceability testing program to evaluate the radioanalytical capabilities of participating laboratories. The NIST Radiochemistry Intercomparison Program (NRIP) started more than 10 years ago, and emergency performance testing was added to the program seven years ago. Radiobioassay turnaround times under the NRIP program for routine production and under emergency response scenarios are 60 d and 8 h, respectively. Because measurement accuracy and sample turnaround time are very critical in a radiological emergency, response laboratories' analytical systems are best evaluated and improved through traceable Performance Testing (PT) programs. The NRIP provides participant laboratories with metrology tools to evaluate their performance and to improve it. The program motivates the laboratories to optimize their methodologies and minimize the turnaround time of their results. Likewise, NIST has to make adjustments and periodical changes in the bioassay test samples in order to challenge the participating laboratories continually. With practice, radioanalytical measurements turnaround time can be reduced to 3-4 h.

International intercomparison of measuring instruments for radon/thoron gas and radon short-lived daughter products in the NRPI Prague.

PubMed

Jílek, K; Hýža, M; Kotík, L; Thomas, J; Tomášek, L

2014-07-01

During the 7th European Conference on Protection Against Radon at Home and at Work held in the autumn of 2013 in Prague, the second intercomparison of measuring instruments for radon and its short-lived decay products and the first intercomparison of radon/thoron gas discriminative passive detectors in mix field of radon/thoron were organised by and held at the Natural Radiation Division of the National Radiation Protection Institute (NRPI) in Prague. In total, 14 laboratories from 11 different countries took part in the 2013 NRPI intercomparison. They submitted both continuous monitors for the measurement of radon gas and equivalent equilibrium radon concentration in a big NRPI chamber (48 m3) and sets of passive detectors including radon/thoron discriminative for the measurement of radon gas in the big chamber and thoron gas in a small thoron chamber (150 dm3). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Intercomparison of TCCON and MUSICA Water Vapour Products

NASA Astrophysics Data System (ADS)

Weaver, D.; Strong, K.; Deutscher, N. M.; Schneider, M.; Blumenstock, T.; Robinson, J.; Notholt, J.; Sherlock, V.; Griffith, D. W. T.; Barthlott, S.; García, O. E.; Smale, D.; Palm, M.; Jones, N. B.; Hase, F.; Kivi, R.; Ramos, Y. G.; Yoshimura, K.; Sepúlveda, E.; Gómez-Peláez, Á. J.; Gisi, M.; Kohlhepp, R.; Warneke, T.; Dohe, S.; Wiegele, A.; Christner, E.; Lejeune, B.; Demoulin, P.

2014-12-01

We present an intercomparison between the water vapour products from the Total Carbon Column Observing Network (TCCON) and the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA), two datasets from ground-based Fourier Transform InfraRed (FTIR) spectrometers with good global representation. Where possible, comparisons to radiosondes are also included. The near-infrared TCCON measurements are optimized to provide precise monitoring of greenhouse gases for carbon cycle studies; however, TCCON's retrievals also produce water vapour products. The mid-infrared MUSICA products result from retrievals optimized to give precise and accurate information about H2O, HDO, and δD. The MUSICA water vapour products have been validated by extensive intercomparisons with H2O and δD in-situ measurements made from ground, radiosonde, and aircraft (Schneider et al. 2012, 2014), as well as by intercomparisons with satellite-based H2O and δD remote sensing measurements (Wiegele et al., 2014). This dataset provides a valuable reference point for other measurements of water vapour. This study is motivated by the limited intercomparisons performed for TCCON water vapour products and limited characterisation of their uncertainties. We compare MUSICA and TCCON products to assess the potential for TCCON measurements to contribute to studies of the water cycle, water vapour's role in climate and use as a tracer for atmospheric dynamics, and to evaluate the performance of climate models. The TCCON and MUSICA products result from measurements taken using the same FTIR instruments, enabling a comparison with constant instrumentation. The retrieval techniques differ, however, in their method and a priori information. We assess the impact of these differences and characterize the comparability of the TCCON and MUSICA datasets.

An intercomparison of aircraft instrumentation for tropospheric measurements of sulfur dioxide

NASA Technical Reports Server (NTRS)

Gregory, Gerald L.; Davis, Douglas D.; Beltz, Nobert; Bandy, Alan R.; Ferek, Ronald J.; Thornton, Donald C.

1993-01-01

As part of the NASA Tropospheric Chemistry Program, a series of field intercomparisons have been conducted to evaluate the state-of-the art for measuring key tropospheric species. One of the objectives of the third intercomparison campaign in this series, Chemical Instrumentation Test and Evaluation 3 (CITE 3), was to evaluate instrumentation for making reliable tropospheric aircraft measurements of sulfur dioxide, dimethyl sulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide. This paper reports the results of the intercomparisons of five sulfur dioxide measurement methods ranging from filter techniques, in which samples collected in flight are returned to the laboratory for analyses (chemiluminescent or ion chromatographic), to near real-time, in-flight measurements via gas chromatographic, mass spectrometric, and chemiluminescent techniques. All techniques showed some tendency to track sizeable changes in ambient SO2 such as those associated with altitude changes. For SO2 mixing ratios in the range of 200 pptv to a few ppbv, agreement among the techniques varies from about 30% to several orders of magnitude, depending upon the pair of measurements intercompared. For SO2 mixing ratios less than 200 pptv, measurements from the techniques are uncorrelated. In general, observed differences in the measurement of standards do not account for the flight results. The CITE 3 results do not unambiguously identify one or more of the measurement techniques as providing valid or invalid SO2 measurements, but identify the range of 'potential' uncertainty in SO2 measurements reported by currently available instrumentation and as measured under realistic aircraft environments.

Intercomparison of hydrologic processes in global climate models

NASA Technical Reports Server (NTRS)

Lau, W. K.-M.; Sud, Y. C.; Kim, J.-H.

1995-01-01

In this report, we address the intercomparison of precipitation (P), evaporation (E), and surface hydrologic forcing (P-E) for 23 Atmospheric Model Intercomparison Project (AMIP) general circulation models (GCM's) including relevant observations, over a variety of spatial and temporal scales. The intercomparison includes global and hemispheric means, latitudinal profiles, selected area means for the tropics and extratropics, ocean and land, respectively. In addition, we have computed anomaly pattern correlations among models and observations for different seasons, harmonic analysis for annual and semiannual cycles, and rain-rate frequency distribution. We also compare the joint influence of temperature and precipitation on local climate using the Koeppen climate classification scheme.

The role of inter-comparisons in radiocarbon quality assurance

NASA Astrophysics Data System (ADS)

Scott, Marian; Cook, Gordon; Naysmith, Philip

2016-04-01

Radiocarbon dating is used widely in many geochronology projects as a basis for the creation and testing of chronological constructs. Radiocarbon measurements are by their nature complex and the degree of sample pre-treatment varies considerably depending on the material. Within the UK and Europe, there are a number of well-established laboratories and increasingly, scientists are not just commissioning new dates, but also using statistical modelling of assemblages of dates, perhaps measured in different laboratories, to provide formal date estimates for their investigations. The issue of comparability of measurements (and thus bias, accuracy and precision of measurement) from the diverse laboratories is one which has been the focus of some attention both within the 14C community and the wider user communities for some time. As a result of this but also as part of laboratory benchmarking and quality assurance, the 14C community has undertaken a wide-scale, far-reaching and evolving programme of inter-comparisons, to the benefit of laboratories and users alike. This paper presents the results from the most recent exercise SIRI. The objectives of SIRI included, through choice of material, to contribute to the discussion concerning laboratory offsets and error multipliers in the context of IntCal (the International Calibration Programme) and to gain a better understanding of differences in background derived from a range of infinite age material types.

An intercomparison of nitric oxide measurement techniques

NASA Technical Reports Server (NTRS)

Hoell, J. M., Jr.; Gregory, G. L.; Mcdougal, D. S.; Carroll, M. A.; Mcfarland, M.; Ridley, B. A.; Davis, D. D.; Bradshaw, J.; Rodgers, M. O.; Torres, A. L.

1985-01-01

Results from an intercomparison of techniques to measure tropospheric levels of nitric oxide (NO) are discussed. The intercomparison was part of the National Aeronautics and Space Administration's Global Tropospheric Experiment and was conducted at Wallops Island, VA, in July 1983. Instruments intercompared included a laser-induced fluorescence system and two chemiluminescence instruments. The intercomparisons were performed with ambient air at NO mixing ratios ranging from 10 to 60 pptv and NO-enriched ambient air at mixing ratios from 20 to 170 pptv. All instruments sampled from a common manifold. The techniques exhibited a high degree of correlation among themselves and with changes in the NO mixing ratio. Agreement among the three techniques was placed at approximately + or - 30 percent. Within this level of agreement, no artifacts or species interferences were identified.

Solid precipitation measurement intercomparison in Bismarck, North Dakota, from 1988 through 1997

USGS Publications Warehouse

Ryberg, Karen R.; Emerson, Douglas G.; Macek-Rowland, Kathleen M.

2009-01-01

A solid precipitation measurement intercomparison was recommended by the World Meteorological Organization (WMO) and was initiated after approval by the ninth session of the Commission for Instruments and Methods of Observation. The goal of the intercomparison was to assess national methods of measuring solid precipitation against methods whose accuracy and reliability were known. A field study was started in Bismarck, N. Dak., during the 1988-89 winter as part of the intercomparison. The last official field season of the WMO intercomparison was 1992-93; however, the Bismarck site continued to operate through the winter of 1996-97. Precipitation events at Bismarck were categorized as snow, mixed, or rain on the basis of descriptive notes recorded as part of the solid precipitation intercomparison. The rain events were not further analyzed in this study. Catch ratios (CRs) - the ratio of the precipitation catch at each gage to the true precipitation measurement (the corrected double fence intercomparison reference) - were calculated. Then, regression analysis was used to develop equations that model the snow and mixed precipitation CRs at each gage as functions of wind speed and temperature. Wind speed at the gages, functions of temperature, and upper air conditions (wind speed and air temperature at 700 millibars pressure) were used as possible explanatory variables in the multiple regression analysis done for this study. The CRs were modeled by using multiple regression analysis for the Tretyakov gage, national shielded gage, national unshielded gage, AeroChem gage, national gage with double fence, and national gage with Wyoming windshield. As in earlier studies by the WMO, wind speed and air temperature were found to influence the CR of the Tretyakov gage. However, in this study, the temperature variable represented the average upper air temperature over the duration of the event. The WMO did not use upper air conditions in its analysis. The national shielded and

INTERCOMPARISON OF OPTICAL REMOTE SENSING SYSTEMS FOR ROADSIDE MEASUREMENTS

EPA Science Inventory

The presentation describes results of an intercomparison of three optical remote sensing systems for measurements of nitric oxide emitted from passenger cars and light-duty trucks. The intercomparison included a standards comparison to establish comparability of standards, follo...

Inter-comparison of automatic rain gauges

NASA Technical Reports Server (NTRS)

Nystuen, Jeffrey A.

1994-01-01

The Ocean Acoustics Division (OAD) of the Atlantic Oceanographic and Meteorological Laboratory (AOML), in cooperation with NOAA/NESDIS and NASA, has deployed six rain gauges for calibration and intercomparison purposes. These instruments include: (1) a weighing rain gauge, (2) a RM Young Model 50202 capacitance rain gauge, (3) a ScTI ORG-705 (long path) optical rain gauge, (4) a ScTI ORG-105 (mini-ORG) optical rain gauge, (5) a Belfort Model 382 tipping bucket rain gauge, and (6) a Distromet RD-69 disdrometer. The system has been running continuously since July 1993. During this time period, roughly 150 events with maximum rainfall rate over 10 mm/hr and 25 events with maximum rainfall rates over 100 mm/hr have been recorded. All rain gauge types have performed well, with intercorrelations 0.9 or higher. However, limitations for each type of rain gauge have been observed.

Pliocene Model Intercomparison (PlioMIP) Phase 2: Scientific Objectives and Experimental Design

NASA Technical Reports Server (NTRS)

Haywood, A. M.; Dowsett, H. J.; Dolan, A. M.; Rowley, D.; Abe-Ouchi, A.; Otto-Bliesner, B.; Chandler, M. A.; Hunter, S. J.; Lunt, D. J.; Pound, M.;

Airborne sulfur trace species intercomparison campaign: Sulfur dioxide, dimethylsulfide, hydrogen sulfide, carbon disulfide, and carbonyl sulfide

NASA Technical Reports Server (NTRS)

Gregory, Gerald L.; Hoell, James M., Jr.; Davis, Douglas D.

1991-01-01

Results from an airborne intercomparison of techniques to measure tropospheric levels of sulfur trace gases are presented. The intercomparison was part of the NASA Global Tropospheric Experiment (GTE) and was conducted during the summer of 1989. The intercomparisons were conducted on the Wallops Electra aircraft during flights from Wallops Island, Virginia, and Natal, Brazil. Sulfur measurements intercompared included sulfur dioxide (SO2), dimethylsulfide (DMS), hydrogen sulfide (H2S), carbon disulfide (CS2), and carbonyl sulfide (OCS). Measurement techniques ranged from filter collection systems with post-flight analyses to mass spectrometer and gas chromatograph systems employing various methods for measuring and identifying the sulfur gases during flight. Sampling schedules for the techniques ranged from integrated collections over periods as long as 50 minutes to one- to three-minute samples every ten or fifteen minutes. Several of the techniques provided measurements of more than one sulfur gas. Instruments employing different detection principles were involved in each of the sulfur intercomparisons. Also included in the intercomparison measurement scenario were a host of supporting measurements (i.e., ozone, nitrogen oxides, carbon monoxide, total sulfur, aerosols, etc.) for purposes of: (1) interpreting results (i.e., correlation of any noted instrument disagreement with the chemical composition of the measurement environment); and (2) providing supporting chemical data to meet CITE-3 science objectives of studying ozone/sulfur photochemistry, diurnal cycles, etc. The results of the intercomparison study are briefly discussed.

INTERCOMPARISON STUDY OF ATMOSPHERIC MERCURY MODELS: 2. MODELING RESULTS VS. LONG-TERM OBSERVATIONS AND COMPARISON OF COUNTRY ATMOSPHERIC BALANCES

EPA Science Inventory

Five regional scale models with a horizontal domain covering the European continent and its surrounding seas, two hemispheric and one global scale model participated in the atmospheric Hg modelling intercomparison study. The models were compared between each other and with availa...

Low-cost solar array project: Four absolute cavity radiometer (pyrheliometer) intercomparisons at New River, Arizona: Radiometer standards

NASA Technical Reports Server (NTRS)

Estey, R. S.; Seaman, C. H.

1981-01-01

Four detailed intercomparisons were made for a number of models of cavity-type self-calibrating radiometers (pyrheliometers). Each intercomparison consisted of simultaneous readings of pyrheliometers at 30-second intervals in runs of 10 minutes, with at least 15 runs per intercomparison. Twenty-seven instruments were in at least one intercomparison, and five were in all four. Summarized results and all raw data are provided from the intercomparisons.

Performance evaluation of elemental analysis/isotope ratio mass spectrometry methods for the determination of the D/H ratio in tetramethylurea and other compounds--results of a laboratory inter-comparison.

PubMed

Bréas, Olivier; Thomas, Freddy; Zeleny, Reinhard; Calderone, Giovanni; Jamin, Eric; Guillou, Claude

2007-01-01

Tetramethylurea (TMU) with a certified D/H ratio is the internal standard for Site-specific Natural Isotope Fractionation measured by Nuclear Magnetic Resonance (SNIF-NMR) analysis of wine ethanol for detection of possible adulterations (Commission Regulation 2676/90). A new batch of a TMU certified reference material (CRM) is currently being prepared. Whereas SNIF-NMR has been employed up to now, Elemental Analysis/Isotope Ratio Mass Spectrometry ((2)H-EA-IRMS) was envisaged as the method of choice for value assignment of the new CRM, as more precise (better repeatable) data might be obtained, resulting in lower uncertainty of the certified value. In order to evaluate the accuracy and intra- and inter-laboratory reproducibility of (2)H-EA-IRMS methods, a laboratory inter-comparison was carried out by analysing TMU and other organic compounds, as well as some waters. The results revealed that experienced laboratories are capable of generating robust and well comparable data, which highlights the emerging potential of IRMS in food authenticity testing. However, a systematic bias between IRMS and SNIF-NMR reference data was observed for TMU; this lack of data consistency rules out the (2)H-IRMS technique for the characterisation measurement of the new TMU CRM.

Manufacture and calibration of optical supersmooth roughness artifacts for intercomparisons

NASA Astrophysics Data System (ADS)

Ringel, Gabriele A.; Kratz, Frank; Schmitt, Dirk-Roger; Mangelsdorf, Juergen; Creuzet, Francois; Garratt, John D.

1995-09-01

Intercomparison roughness measurements have been carried out on supersmooth artifacts fabricated from BK7, fused silica, and Zerodur. The surface parameters were determined using the optical heterodyne profiler Z5500 (Zygo), a special prototype of the mechanical profiler Nanostep (Rank Taylor Hobson), and an Atomic Force Microscope (Park Scientific Instruments) with an improved acquisition technique. The intercomparison was performed after the range of collected spatial wavelengths for each instrument was adjusted using digital filtering techniques. It is demonstrated for different roughness ranges that the applied superpolishing techniques yield supersmooth artifacts which can be used for more intercomparisons. More than 100 samples were investigated. Criteria were developed to select artifacts from the sample stock.

ACIX: Atmospheric Correction Inter-comparison Exercise

NASA Astrophysics Data System (ADS)

Doxani, Georgia; Gascon, Ferran; Vermote, Éric; Roger, Jean-Claude

2017-04-01

The free and open data access policy to Sentinel-2 (S-2) and Landsat-8 (L-8) satellite imagery has stimulated the development of atmospheric correction (AC) processors for generating Bottom-of-Atmosphere (BOA) products. Several entities have started to generate (or plan to generate in the short term) BOA reflectance products at global scale for S-2 and L-8 missions. To this end, the European Space Agency (ESA) and NASA are organizing an exercise on AC processors inter-comparison. The results of the exercise are expected to point out the strengths and weaknesses, as well as communalities and discrepancies of various AC processors, in order to suggest and define ways for their further improvement. In particular, 13 atmospheric processors from five different countries participate in ACIX with the aim to inter-compare their performance when applied to L-8 and S-2 data. A protocol describing the inter-comparison process and the test dataset, which is based on the AERONET sites, will be presented. The protocol has been defined according to what was agreed among the participants during the 1st ACIX workshop held in June 2016. It includes the comparison of aerosol optical thickness and water vapour products of the processors with the AERONET measurements. Moreover, concerning the surface reflectances, the protocol describes the inter-comparison among the processors, as well as the comparison with the MODIS surface reflectance and with a reference surface reflectance product. Such a reference product will be obtained using the AERONET characterization of the aerosol (size distribution and refractive indices) and an accurate radiative transfer code. The inter-comparison outcomes will be presented and discussed among the participants in the 2nd ACIX workshop, which will be held on 11-12 April 2017 (ESRIN/ESA). The proposed presentation is an opportunity for the user community to be informed for the first time about the ACIX results and conclusions.

Estimating near-road pollutant dispersion: a model inter-comparison

EPA Science Inventory

A model inter-comparison study to assess the abilities of steady-state Gaussian dispersion models to capture near-road pollutant dispersion has been carried out with four models (AERMOD, run with both the area-source and volume-source options to represent roadways, CALINE, versio...

Inter-comparison of boron concentration measurements at INFN-University of Pavia (Italy) and CNEA (Argentina).

PubMed

Portu, Agustina; Postuma, Ian; Gadan, Mario Alberto; Saint Martin, Gisela; Olivera, María Silvina; Altieri, Saverio; Protti, Nicoletta; Bortolussi, Silva

2015-11-01

An inter-comparison of three boron determination techniques was carried out between laboratories from INFN-University of Pavia (Italy) and CNEA (Argentina): alpha spectrometry (alpha-spect), neutron capture radiography (NCR) and quantitative autoradiography (QTA). Samples of different nature were analysed: liquid standards, liver homogenates and tissue samples from different treatment protocols. The techniques showed a good agreement in a concentration range of interest in BNCT (1-100ppm), thus demonstrating their applicability as precise methods to quantify boron and determine its distribution in tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Methodological Inter-Comparison of Gridded Meteorological Products

NASA Astrophysics Data System (ADS)

Newman, A. J.; Clark, M. P.; Longman, R. J.; Giambelluca, T. W.; Arnold, J.

2017-12-01

Here we present a gridded meteorology inter-comparison using the state of Hawaíi as a testbed. This inter-comparison is motivated by two general goals: 1) the broad user community of gridded observation based meteorological fields should be aware of inter-product differences and the reasons they exist, which allows users to make informed choices on product selection to best meet their specific application(s); 2) we want to demonstrate the utility of inter-comparisons to meet the first goal, yet highlight that they are limited to mostly generic statements regarding attribution of differences that limits our understanding of these complex algorithms and obscures future research directions. Hawaíi is a useful testbed because it is a meteorologically complex region with well-known spatial features that are tied to specific physical processes (e.g. the trade wind inversion). From a practical standpoint, there are now several monthly climatological and daily precipitation and temperature datasets available that are being used for impact modeling. General conclusions that have emerged are: 1) differences in input station data significantly influence product differences; 2) prediction of precipitation occurrence is crucial across multiple metrics; 3) derived temperature statistics (e.g. diurnal temperature range) may have large spatial differences across products; and 4) attribution of differences to methodological choices is difficult and may limit the outcomes of these inter-comparisons, particularly from a development viewpoint. Thus, we want to continue to move the community towards frameworks that allow for multiple options throughout the product generation chain and allow for more systematic testing.

Intercomparison study of atmospheric methane and carbon dioxide concentrations measured at the Ebre River Delta Station

NASA Astrophysics Data System (ADS)

Occhipinti, Paola; Morguí, Josep Anton; Àgueda, Alba; Batet, Oscar; Borràs, Sílvia; Cañas, Lídia; Curcoll, Roger; Grossi, Claudia; Nofuentes, Manel; Vazquez, Eusebi; Rodó, Xavier

2015-04-01

In the framework of the ClimaDat project, IC3 has established a network of eight monitoring stations across the Iberian Peninsula and the Canarian Archipelago with the aim of studying climate processes. The monitoring station at the Ebre River Delta (DEC3) is located in the Ebre River Delta Natural Park (40° 44' N; 0° 47' E) and it is characterized by the typical North-Western Mediterranean climate. Since 2013, atmospheric greenhouse gases (GHG) and 222Rn tracer gas together with the meteorological parameters are continuously measured from a 10 m a.g.l. height tower. Atmospheric GHG (CO2, CH4, CO and N2O) concentrations are determined using a Picarro analyzer G2301 (CO2 and CH4) and a modified gas chromatograph (GC) Agilent 6890N (CO2, CH4, CO and N2O). Open data access is available from the www.climadat.es website. Data collected at the DEC3 station are also submitted to the InGOS platform since this station is part of the InGOS European infrastructure project. Researchers from the Laboratory of the Atmosphere and the Oceans (LAO) at IC3 have performed an intercomparison study at the DEC3 site between three different Picarro analyzers (two Picarro G2301 and one Picarro G2301M), a Los Gatos Research (LGR) analyzer and the GC system already installed at the station. The aim of this study is to compare and assess the measuring agreement between the four optical gas analyzers and the GC. In the first part of the experiment, all instruments have been calibrated using NOAA gases as primary standards analyzing five Praxair provided targets to evaluate the precision of the measuring instruments. Max Plank Institute (MPI) gases have been used as secondary standards for the GC whereas Praxair provided tanks are used as secondary standards for the Picarro and the LGR analyzers. In the second part of the experiment, atmospheric GHG were measured from natural atmospheric air taken from a 10 m a.g.l. inlet. Daily cycles of GHG measurements were carried out using different

ISMIP6: Ice Sheet Model Intercomparison Project for CMIP6

NASA Technical Reports Server (NTRS)

Nowicki, S.

2015-01-01

ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6) targets the Cryosphere in a Changing Climate and the Future Sea Level Grand Challenges of the WCRP (World Climate Research Program). Primary goal is to provide future sea level contribution from the Greenland and Antarctic ice sheets, along with associated uncertainty. Secondary goal is to investigate feedback due to dynamic ice sheet models. Experiment design uses and augment the existing CMIP6 (Coupled Model Intercomparison Project Phase 6) DECK (Diagnosis, Evaluation, and Characterization of Klima) experiments. Additonal MIP (Model Intercomparison Project)- specific experiments will be designed for ISM (Ice Sheet Model). Effort builds on the Ice2sea, SeaRISE (Sea-level Response to Ice Sheet Evolution) and COMBINE (Comprehensive Modelling of the Earth System for Better Climate Prediction and Projection) efforts.

Criticality accident dosimetry systems: an international intercomparison at the SILENE reactor in 2002.

PubMed

Médioni, R; Asselineau, B; Verrey, B; Trompier, F; Itié, C; Texier, C; Muller, H; Pelcot, G; Clairand, I; Jacquet, X; Pochat, J L

2004-01-01

In criticality accident dosimetry and more generally for high dose measurements, special techniques are used to measure separately the gamma ray and neutron components of the dose. To improve these techniques and to check their dosimetry systems (physical and/or biological), a total of 60 laboratories from 29 countries (America, Europe, Asia) participated in an international intercomparaison, which took place in France from 9 to 21 June 2002, at the SILENE reactor in Valduc and at a pure gamma source in Fontenay-aux-Roses. This intercomparison was jointly organised by the IRSN and the CEA with the help of the NEA/OCDE and was partly supported by the European Communities. This paper describes the aim of this intercomparison, the techniques used by the participants and the two radiation sources and their characteristics. The experimental arrangements of the dosemeters for the irradiations in free air or on phantoms are given. Then the dosimetric quantities measured and reported by the participants are summarised, analysed and compared with the reference values. The present paper concerns only the physical dosimetry and essentially experiments performed on the SILENE facility. The results obtained with the biological dosimetry are published in two other papers of this issue.

Trilateral Intercomparison of Photometric Units Maintained at NIST (USA), NPL (UK), and PTB (Germany)

PubMed Central

Ohno, Yoshi; Goodman, Teresa; Sauter, Georg

1999-01-01

A trilateral intercomparison of photometric units between NIST (USA), NPL (UK), and PTB (Germany) has been conducted to update the knowledge of the relationship between the photometric units disseminated in the three countries. The luminous intensity unit (cd), the luminous responsivity scale (A/lx), and the luminous flux unit (lm) maintained at each laboratory were compared by circulating transfer standard lamps and photometers. The results showed that the relative luminous intensity values, with respect to the average, measured by NIST, NPL, and PTB were 1.0014, 1.0021, and 0.9966; the relative inverse values of the luminous responsivity (corresponding to illuminance) were 1.0023, 1.0011, and 0.9965; the relative luminous flux values were 0.9994, 1.0034, and 0.9972, respectively. The results agreed within the stated uncertainties of the units maintained at the three laboratories.

Atmospheric Correction Inter-comparison Exercise (ACIX)

NASA Astrophysics Data System (ADS)

Vermote, E.; Doxani, G.; Gascon, F.; Roger, J. C.; Skakun, S.

2017-12-01

The free and open data access policy to Landsat-8 (L-8) and Sentinel-2 (S-2) satellite imagery has encouraged the development of atmospheric correction (AC) approaches for generating Bottom-of-Atmosphere (BOA) products. Several entities have started to generate (or plan to generate in the short term) BOA reflectance products at global scale for L-8 and S-2 missions. To this end, the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) have initiated an exercise on the inter-comparison of the available AC processors. The results of the exercise are expected to point out the strengths and weaknesses, as well as communalities and discrepancies of various AC processors, in order to suggest and define ways for their further improvement. In particular, 11 atmospheric processors from five different countries participate in ACIX with the aim to inter-compare their performance when applied to L-8 and S-2 data. All the processors should be operational without requiring parametrization when applied on different areas. A protocol describing in details the inter-comparison metrics and the test dataset based on the AERONET sites has been agreed unanimously during the 1st ACIX workshop in June 2016. In particular, a basic and an advanced run of each of the processor were requested in the frame of ACIX, with the aim to draw robust and reliable conclusions on the processors' performance. The protocol also describes the comparison metrics of the aerosol optical thickness and water vapour products of the processors with the corresponding AERONET measurements. Moreover, concerning the surface reflectances, the inter-comparison among the processors is defined, as well as the comparison with the MODIS surface reflectance and with a reference surface reflectance product. Such a reference product will be obtained using the AERONET characterization of the aerosol (size distribution and refractive indices) and an accurate radiative transfer code. The inter-comparison

SECOND LATIN AMERICAN INTERCOMPARISON ON INTERNAL DOSE ASSESSMENT.

PubMed

Rojo, A; Puerta, N; Gossio, S; Gómez Parada, I; Cruz Suarez, R; López, E; Medina, C; Lastra Boylan, J; Pinheiro Ramos, M; Mora Ramírez, E; Alves Dos Reis, A; Yánez, H; Rubio, J; Vironneau Janicek, L; Somarriba Vanegas, F; Puerta Ortiz, J; Salas Ramírez, M; López Bejerano, G; da Silva, T; Miri Oliveira, C; Terán, M; Alfaro, M; García, T; Angeles, A; Duré Romero, E; Farias de Lima, F

2016-09-01

Internal dosimetry intercomparisons are essential for the verification of applied models and the consistency of results'. To that aim, the First Regional Intercomparison was organised in 2005, and that results led to the Second Regional Intercomparison Exercise in 2013, which was organised in the frame of the RLA 9/066 and coordinated by Autoridad Regulatoria Nuclear of Argentina. Four simulated cases covering intakes of (131)I, (137)Cs and Tritium were proposed. Ninteen centres from thirteen different countries participated in this exercise. This paper analyses the participants' results in this second exercise in order to test their skills and acquired knowledge, particularly in the application of the IDEAS Guidelines. It is important to highlight the increased number of countries that participated in this exercise compared with the first one and, furthermore, the improvement in the overall performance. The impact of the International Atomic Energy Agency (IAEA) Projects since 2003 has led to a significant enhancement of internal dosimetry capabilities that strengthen the radiation protection of workers. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Web-based Reanalysis Intercomparison Tools (WRIT): Comparing Reanalyses and Observational data.

NASA Astrophysics Data System (ADS)

Compo, G. P.; Smith, C. A.; Hooper, D. K.

2014-12-01

While atmospheric reanalysis datasets are widely used in climate science, many technical issues hinder comparing them to each other and to observations. The reanalysis fields are stored in diverse file architectures, data formats, and resolutions, with metadata, such as variable name and units, that also differ. Individual users have to download the fields, convert them to a common format, store them locally, change variable names, re-grid if needed, and convert units. Comparing reanalyses with observational datasets is difficult for similar reasons. Even if a dataset can be read via Open-source Project for a Network Data Access Protocol (OPeNDAP) or a similar protocol, most of this work is still needed. All of these tasks take time, effort, and money. To overcome some of the obstacles in reanalysis intercomparison, our group at the Cooperative Institute for Research in the Environmental Sciences (CIRES) at the University of Colorado and affiliated colleagues at National Oceanic and Atmospheric Administration's (NOAA's) Earth System Research Laboratory Physical Sciences Division (ESRL/PSD) have created a set of Web-based Reanalysis Intercomparison Tools (WRIT) at http://www.esrl.noaa.gov/psd/data/writ/. WRIT allows users to easily plot and compare reanalysis and observational datasets, and to test hypotheses. Currently, there are tools to plot monthly mean maps and vertical cross-sections, timeseries, and trajectories for standard pressure level and surface variables. Users can refine dates, statistics, and plotting options. Reanalysis datasets currently available include the NCEP/NCAR R1, NCEP/DOE R2, MERRA, ERA-Interim, NCEP CFSR and the 20CR. Observational datasets include those containing precipitation (e.g. GPCP), temperature (e.g. GHCNCAMS), winds (e.g. WASWinds), precipitable water (e.g. NASA NVAP), SLP (HadSLP2), and SST (NOAA ERSST). WRIT also facilitates the mission of the Reanalyses.org website as a convenient toolkit for studying the reanalysis datasets.

Subglacial Hydrology Model Intercomparison Project (SHMIP)

NASA Astrophysics Data System (ADS)

Werder, Mauro A.; de Fleurian, Basile; Creyts, Timothy T.; Damsgaard, Anders; Delaney, Ian; Dow, Christine F.; Gagliardini, Olivier; Hoffman, Matthew J.; Seguinot, Julien; Sommers, Aleah; Irarrazaval Bustos, Inigo; Downs, Jakob

2017-04-01

The SHMIP project is the first intercomparison project of subglacial drainage models (http://shmip.bitbucket.org). Its synthetic test suites and evaluation were designed such that any subglacial hydrology model producing effective pressure can participate. In contrast to ice deformation, the physical processes of subglacial hydrology (which in turn impacts basal sliding of glaciers) are poorly known. A further complication is that different glacial and geological settings can lead to different drainage physics. The aim of the project is therefore to qualitatively compare the outputs of the participating models for a wide range of water forcings and glacier geometries. This will allow to put existing studies, which use different drainage models, into context and will allow new studies to select the most suitable model for the problem at hand. We present the results from the just completed intercomparison exercise. Twelve models participated: eight 2D and four 1D models; nine include both an efficient and inefficient system, the other three one of the systems; all but two models use R-channels as efficient system, and/or a linked-cavity like inefficient system, one exception uses porous layers with different characteristic for each of the systems, the other exception is based on canals. The main variable used for the comparison is effective pressure, as that is a direct proxy for basal sliding of glaciers. The models produce large differences in the effective pressure fields, in particular for higher water input scenarios. This shows that the selection of a subglacial drainage model will likely impact the conclusions of a study significantly.

RENEB intercomparisons applying the conventional Dicentric Chromosome Assay (DCA).

PubMed

Oestreicher, Ursula; Samaga, Daniel; Ainsbury, Elizabeth; Antunes, Ana Catarina; Baeyens, Ans; Barrios, Leonardo; Beinke, Christina; Beukes, Philip; Blakely, William F; Cucu, Alexandra; De Amicis, Andrea; Depuydt, Julie; De Sanctis, Stefania; Di Giorgio, Marina; Dobos, Katalin; Dominguez, Inmaculada; Duy, Pham Ngoc; Espinoza, Marco E; Flegal, Farrah N; Figel, Markus; Garcia, Omar; Monteiro Gil, Octávia; Gregoire, Eric; Guerrero-Carbajal, C; Güçlü, İnci; Hadjidekova, Valeria; Hande, Prakash; Kulka, Ulrike; Lemon, Jennifer; Lindholm, Carita; Lista, Florigio; Lumniczky, Katalin; Martinez-Lopez, Wilner; Maznyk, Nataliya; Meschini, Roberta; M'kacher, Radia; Montoro, Alegria; Moquet, Jayne; Moreno, Mercedes; Noditi, Mihaela; Pajic, Jelena; Radl, Analía; Ricoul, Michelle; Romm, Horst; Roy, Laurence; Sabatier, Laure; Sebastià, Natividad; Slabbert, Jacobus; Sommer, Sylwester; Stuck Oliveira, Monica; Subramanian, Uma; Suto, Yumiko; Que, Tran; Testa, Antonella; Terzoudi, Georgia; Vral, Anne; Wilkins, Ruth; Yanti, LusiYanti; Zafiropoulos, Demetre; Wojcik, Andrzej

2017-01-01

Two quality controlled inter-laboratory exercises were organized within the EU project 'Realizing the European Network of Biodosimetry (RENEB)' to further optimize the dicentric chromosome assay (DCA) and to identify needs for training and harmonization activities within the RENEB network. The general study design included blood shipment, sample processing, analysis of chromosome aberrations and radiation dose assessment. After manual scoring of dicentric chromosomes in different cell numbers dose estimations and corresponding 95% confidence intervals were submitted by the participants. The shipment of blood samples to the partners in the European Community (EU) were performed successfully. Outside the EU unacceptable delays occurred. The results of the dose estimation demonstrate a very successful classification of the blood samples in medically relevant groups. In comparison to the 1st exercise the 2nd intercomparison showed an improvement in the accuracy of dose estimations especially for the high dose point. In case of a large-scale radiological incident, the pooling of ressources by networks can enhance the rapid classification of individuals in medically relevant treatment groups based on the DCA. The performance of the RENEB network as a whole has clearly benefited from harmonization processes and specific training activities for the network partners.

An Analysis of Simulated Wet Deposition of Mercury from the North American Mercury Model Intercomparison Study

EPA Science Inventory

A previous intercomparison of atmospheric mercury models in North America has been extended to compare simulated and observed wet deposition of mercury. Three regional-scale atmospheric mercury models were tested; CMAQ, REMSAD and TEAM. These models were each employed using thr...

An International Marine-Atmospheric 222Rn Measurement Intercomparison in Bermuda Part I: NIST Calibration and Methodology for Standardized Sample Additions

PubMed Central

Collé, R.; Unterweger, M. P.; Hodge, P. A.; Hutchinson, J. M. R.

1996-01-01

As part of an international 222Rn measurement intercomparison conducted at Bermuda in October 1991, NIST provided standardized sample additions of known, but undisclosed (“blind”) 222Rn concentrations that could be related to U.S. national standards. The standardized sample additions were obtained with a calibrated 226Ra source and a specially-designed manifold used to obtain well-known dilution factors from simultaneous flow-rate measurements. The additions were introduced over sampling periods of several hours (typically 4 h) into a common streamline on a sampling tower used by the participating laboratories for their measurements. The standardized 222Rn activity concentrations for the intercomparison ranged from approximately 2.5 Bq · m−3 to 35 Bq · m−3 (of which the lower end of this range approached concentration levels for ambient Bermudian air) and had overall uncertainties, approximating a 3 standard deviation uncertainty interval, of about 6 % to 13 %. This paper describes the calibration and methodology for the standardized sample additions. PMID:27805090

International NMR-based Environmental Metabolomics Intercomparison Exercise

EPA Science Inventory

Several fundamental requirements must be met so that NMR-based metabolomics and the related technique of metabonomics can be formally adopted into environmental monitoring and chemical risk assessment. Here we report an intercomparison exercise which has evaluated the effectivene...

The Agricultural Model Intercomparison and Improvement Project (AgMIP): Protocols and Pilot Studies

NASA Technical Reports Server (NTRS)

Rosenzweig, C.; Jones, J. W.; Hatfield, J. L.; Ruane, A. C.; Boote, K. J.; Thorburn, P.; Antle, J. M.; Nelson, G. C.; Porter, C.; Janssen, S.;

Satellite Derived Volcanic Ash Product Inter-Comparison in Support to SCOPE-Nowcasting

NASA Astrophysics Data System (ADS)

Siddans, Richard; Thomas, Gareth; Pavolonis, Mike; Bojinski, Stephan

2016-04-01

In support of aeronautical meteorological services, WMO organized a satellite-based volcanic ash retrieval algorithm inter-comparison activity, to improve the consistency of quantitative volcanic ash products from satellites, under the Sustained, Coordinated Processing of Environmental Satellite Data for Nowcasting (SCOPEe Nowcasting) initiative (http:/ jwww.wmo.int/pagesjprogjsatjscopee nowcasting_en.php). The aims of the intercomparison were as follows: 1. Select cases (Sarychev Peak 2009, Eyjafyallajökull 2010, Grimsvötn 2011, Puyehue-Cordón Caulle 2011, Kirishimayama 2011, Kelut 2014), and quantify the differences between satellite-derived volcanic ash cloud properties derived from different techniques and sensors; 2. Establish a basic validation protocol for satellite-derived volcanic ash cloud properties; 3. Document the strengths and weaknesses of different remote sensing approaches as a function of satellite sensor; 4. Standardize the units and quality flags associated with volcanic cloud geophysical parameters; 5. Provide recommendations to Volcanic Ash Advisory Centers (VAACs) and other users on how to best to utilize quantitative satellite products in operations; 6. Create a "road map" for future volcanic ash related scientific developments and inter-comparison/validation activities that can also be applied to SO2 clouds and emergent volcanic clouds. Volcanic ash satellite remote sensing experts from operational and research organizations were encouraged to participate in the inter-comparison activity, to establish the plans for the inter-comparison and to submit data sets. RAL was contracted by EUMETSAT to perform a systematic inter-comparison of all submitted datasets and results were reported at the WMO International Volcanic Ash Inter-comparison Meeting to held on 29 June - 2 July 2015 in Madison, WI, USA (http:/ /cimss.ssec.wisc.edujmeetings/vol_ash14). 26 different data sets were submitted, from a range of passive imagers and spectrometers and

Pliocene Model Intercomparison Project (PlioMIP): Experimental Design and Boundary Conditions (Experiment 2)

NASA Technical Reports Server (NTRS)

Haywood, A. M.; Dowsett, H. J.; Robinson, M. M.; Stoll, D. K.; Dolan, A. M.; Lunt, D. J.; Otto-Bliesner, B.; Chandler, M. A.

2011-01-01

The Palaeoclimate Modelling Intercomparison Project has expanded to include a model intercomparison for the mid-Pliocene warm period (3.29 to 2.97 million yr ago). This project is referred to as PlioMIP (the Pliocene Model Intercomparison Project). Two experiments have been agreed upon and together compose the initial phase of PlioMIP. The first (Experiment 1) is being performed with atmosphere only climate models. The second (Experiment 2) utilizes fully coupled ocean-atmosphere climate models. Following on from the publication of the experimental design and boundary conditions for Experiment 1 in Geoscientific Model Development, this paper provides the necessary description of differences and/or additions to the experimental design for Experiment 2.

Pliocene Model Intercomparison Project (PlioMIP): experimental design and boundary conditions (Experiment 2)

USGS Publications Warehouse

Haywood, A.M.; Dowsett, H.J.; Robinson, M.M.; Stoll, D.K.; Dolan, A.M.; Lunt, D.J.; Otto-Bliesner, B.; Chandler, M.A.

2011-01-01

The Palaeoclimate Modelling Intercomparison Project has expanded to include a model intercomparison for the mid-Pliocene warm period (3.29 to 2.97 million yr ago). This project is referred to as PlioMIP (the Pliocene Model Intercomparison Project). Two experiments have been agreed upon and together compose the initial phase of PlioMIP. The first (Experiment 1) is being performed with atmosphere-only climate models. The second (Experiment 2) utilises fully coupled ocean-atmosphere climate models. Following on from the publication of the experimental design and boundary conditions for Experiment 1 in Geoscientific Model Development, this paper provides the necessary description of differences and/or additions to the experimental design for Experiment 2.

Models and Measurements Intercomparison 2

NASA Technical Reports Server (NTRS)

Park, Jae H. (Editor); Ko, Malcolm K. W. (Editor); Jackman, Charles H. (Editor); Plumb, R. Alan (Editor); Kaye, Jack A. (Editor); Sage, Karen H. (Editor)

1999-01-01

Models and Measurement Intercomparison II (MM II) summarizes the intercomparison of results from model simulations and observations of stratospheric species. Representatives from twenty-three modeling groups using twenty-nine models participated in these MM II exercises between 1996 and 1999. Twelve of the models were two- dimensional zonal-mean models while seventeen were three-dimensional models. This was an international effort as seven were from outside the United States. Six transport experiments and five chemistry experiments were designed for various models. Models participating in the transport experiments performed simulations of chemically inert tracers providing diagnostics for transport. The chemistry experiments involved simulating the distributions of chemically active trace cases including ozone. The model run conditions for dynamics and chemistry were prescribed in order to minimize the factors that caused differences in the models. The report includes a critical review of the results by the participants and a discussion of the causes of differences between modeled and measured results as well as between results from different models, A sizable effort went into preparation of the database of the observations. This included a new climatology for ozone. The report should help in evaluating the results from various predictive models for assessing humankind perturbations of the stratosphere.

Interlaboratory comparison of δ13C and δD measurements of atmospheric CH4 for combined use of data sets from different laboratories

NASA Astrophysics Data System (ADS)

Umezawa, Taku; Brenninkmeijer, Carl A. M.; Röckmann, Thomas; van der Veen, Carina; Tyler, Stanley C.; Fujita, Ryo; Morimoto, Shinji; Aoki, Shuji; Sowers, Todd; Schmitt, Jochen; Bock, Michael; Beck, Jonas; Fischer, Hubertus; Michel, Sylvia E.; Vaughn, Bruce H.; Miller, John B.; White, James W. C.; Brailsford, Gordon; Schaefer, Hinrich; Sperlich, Peter; Brand, Willi A.; Rothe, Michael; Blunier, Thomas; Lowry, David; Fisher, Rebecca E.; Nisbet, Euan G.; Rice, Andrew L.; Bergamaschi, Peter; Veidt, Cordelia; Levin, Ingeborg

2018-03-01

We report results from a worldwide interlaboratory comparison of samples among laboratories that measure (or measured) stable carbon and hydrogen isotope ratios of atmospheric CH4 (δ13C-CH4 and δD-CH4). The offsets among the laboratories are larger than the measurement reproducibility of individual laboratories. To disentangle plausible measurement offsets, we evaluated and critically assessed a large number of intercomparison results, some of which have been documented previously in the literature. The results indicate significant offsets of δ13C-CH4 and δD-CH4 measurements among data sets reported from different laboratories; the differences among laboratories at modern atmospheric CH4 level spread over ranges of 0.5 ‰ for δ13C-CH4 and 13 ‰ for δD-CH4. The intercomparison results summarized in this study may be of help in future attempts to harmonize δ13C-CH4 and δD-CH4 data sets from different laboratories in order to jointly incorporate them into modelling studies. However, establishing a merged data set, which includes δ13C-CH4 and δD-CH4 data from multiple laboratories with desirable compatibility, is still challenging due to differences among laboratories in instrument settings, correction methods, traceability to reference materials and long-term data management. Further efforts are needed to identify causes of the interlaboratory measurement offsets and to decrease those to move towards the best use of available δ13C-CH4 and δD-CH4 data sets.

Inter-comparison between AIRS and IASI through Retrieved Parameters

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Larar, Allen M.; Smith, William L.; Taylor, Jonathan P.; Schluessel, Peter; Strow, L. Larrabee; Mango, Steve

2008-01-01

A State-of-the-art retrieval algorithm dealing with all-weather conditions has been applied to satellite/aircraft instruments retrieving cloud/surface and atmospheric conditions. High quality retrievals have been achieved from IASI data. Surface, cloud, and atmospheric structure and variation are well captured by IASI measurements and/or retrievals. The same retrieval algorithm is also applied to AIRS for retrieval inter-comparison. Both AIRS and IASI have a similar FOV size but AIRS has a higher horizontal resolution. AIRS data can be interpolated to IASI horizontal resolution for inter-comparison at the same geophysical locations, however a temporal variation between AIRS and IASI observations need to be considered. JAIVEx has employed aircraft to obtain the atmospheric variation filling the temporal gap between two satellites. First results show that both AIRS and IASI have a very similar vertical resolving power, atmospheric conditions are well captured by both instruments, and radiances are well calibrated. AIRS data shown in retrievals (e.g., surface emissivity and moisture) have a relatively higher noise level. Since the this type of retrieval is very sensitive to its radiance quality, retrieval products inter-comparison is an effective way to identify/compare their radiance quality, in terms of a combination of spectral resolution and noise level, and to assess instrument performance. Additional validation analyses are needed to provide more-definitive conclusions.

The Inter-Sectoral Impact Model Intercomparison Project (ISI–MIP): Project framework

PubMed Central

Warszawski, Lila; Frieler, Katja; Huber, Veronika; Piontek, Franziska; Serdeczny, Olivia; Schewe, Jacob

2014-01-01

The Inter-Sectoral Impact Model Intercomparison Project offers a framework to compare climate impact projections in different sectors and at different scales. Consistent climate and socio-economic input data provide the basis for a cross-sectoral integration of impact projections. The project is designed to enable quantitative synthesis of climate change impacts at different levels of global warming. This report briefly outlines the objectives and framework of the first, fast-tracked phase of Inter-Sectoral Impact Model Intercomparison Project, based on global impact models, and provides an overview of the participating models, input data, and scenario set-up. PMID:24344316

Water vapour intercomparison effort in the frame of HyMeX-SOP1

NASA Astrophysics Data System (ADS)

Summa, Donato; Di Girolamo, Paolo; Stelitano, Dario; Cacciani, Marco; Flamant, Cyrille; Chazette, Patrick; Ducrocq, Véronique; Nuret, Mathieu; Fourié, Nadia; Richard, Evelyne

2014-05-01

A water vapour intercomparison effort, involving airborne and ground-based water vapour lidar systems and mesoscale models, was carried out in the framework of the international HyMeX (Hydrological cycle in the Mediterranean Experiment) dedicated to the hydrological cycle and related high-impact events. Within HyMeX, a major field campaign was dedicated to heavy precipitation and flash flood events from 5 September to 6 November 2012. The 2 month field campaign took place over the Northwestern Mediterranean Sea and its surrounding coastal regions in France, Italy, and Spain. The main objective of this work is to provide accurate error estimates for the lidar systems i.e. the ground-based Raman lidar BASIL and the CNRS DIAL Leandre 2 on board the ATR42, as well as use BASIL data to validate mesoscale model results from the MESO NH and Arome WMED. The effort will benefit from the few dedicated ATR42 flights in the frame of the EUFAR Project "WaLiTemp". In the present work our attention was focused on two specific case studies: 13 September and 2 October in the altitude region 0.5 - 5.5 km. Comparisons between the ground-based Raman lidar BASIL and the airborne CNRS DIAL indicate a mean relative bias between the two sensors of 6.5%, while comparisons between BASIL and CNRS DIAL vs. the radiosondes indicate a bias of 2.6 and -3.5 %, respectively. The bias of BASIL vs. the ATR insitu sensor indicate a bias of -20.4 %. Specific attention will also be dedicated to the WALI/BASIL intercomparison effort which took place in Candillargues on 30 October 2012. Specific results from this intercomparison effort and from the intercomparison between BASIL and Meso-NH/AROME-WMed will be illustrated and discussed at the Conference.

Intercomparison of three microwave/infrared high resolution line-by-line radiative transfer codes

NASA Astrophysics Data System (ADS)

Schreier, F.; Garcia, S. Gimeno; Milz, M.; Kottayil, A.; Höpfner, M.; von Clarmann, T.; Stiller, G.

2013-05-01

An intercomparison of three line-by-line (lbl) codes developed independently for atmospheric sounding - ARTS, GARLIC, and KOPRA - has been performed for a thermal infrared nadir sounding application assuming a HIRS-like (High resolution Infrared Radiation Sounder) setup. Radiances for the HIRS infrared channels and a set of 42 atmospheric profiles from the "Garand dataset" have been computed. Results of this intercomparison and a discussion of reasons of the observed differences are presented.

Airborne hygrometer calibration inter-comparison against a metrological water vapour standard

NASA Astrophysics Data System (ADS)

Smorgon, Denis; Boese, Norbert; Ebert, Volker

2014-05-01

Water vapour is the most important atmospheric greenhouse gas, which causes a major feedback to warming and other changes in the climate system. Knowledge of the distribution of water vapour and its climate induced changes is especially important in the upper troposphere and lower stratosphere (UT/LS) where vapour plays a critical role in atmospheric radiative balance, cirrus cloud formation, and photochemistry. But, our understanding of water in the UT/LS is limited by significant uncertainties in current UT/LS water measurements. One of the most comprehensive inter-comparison campaigns for airborne hygrometers, termed AQUAVIT (AV1) [1], took place in 2007 at the AIDA chamber at the Karlsruhe Institute of Technology (KIT) in Germany. AV1 was a well-defined, referred, blind inter-comparison of 22 airborne field instruments from 17 international research groups. One major metrological deficit of AV1, however, was, that no traceable reference instrument participated in the inter-comparison experiments and that the calibration procedures of the participating instruments were not monitored or interrogated. Consequently a follow-up inter-comparison was organized in April 2013, which for the first time also provides a traceable link to the international humidity scale. This AQUAVIT2 (AV2) campaign (details see: http://www.imk-aaf.kit.edu/aquavit/index.php/Main_Page) was again located at KIT/AIDA and organised by an international organizing committee including KIT, PTB, FZJ and others. Generally AV2 is divided in two parallel comparisons: 1) AV2-A uses the AIDA chamber for a simultaneous comparison of all instruments (incl. sampling and in-situ instruments) over a broad range of conditions characteristic for the UT/LS; 2) AV2-B, about which this paper is reporting, is a sequential comparison of selected hygrometers and (when possible) their reference calibration infrastructures by means of a chilled mirror hygrometer traced back to the primary National humidity standard

METHODS INTERCOMPARISON OF SAMPLERS FOR EPA'S NATIONAL PM 2.5 CHEMICAL SPECIATION NETWORK

EPA Science Inventory

The objective of this sampler intercomparison field study is to determine the performance characteristics for the collection of the chemical components of PM2.5 by the chemical speciation monitors developed for the national PM2.5 network relative to each other, to the Federal R...

Airborne intercomparison of nitric oxide measurement techniques

NASA Technical Reports Server (NTRS)

Hoell, James M., Jr.; Gregory, Gerald L.; Mcdougal, David S.; Torres, Arnold L.; Davis, Douglas D.

1987-01-01

Results from an airborne intercomparison of techniques to measure tropospheric levels of nitric oxide (NO) are discussed. The intercomparison was part of the National Aeronautics and Space Administration's Global Tropospheric Experiment and was conducted during missions flown in the fall of 1983 and spring of 1984. Instruments intercompared included a laser-induced fluorescence (LIF) system and two chemiluminescence instruments (CL). NO mixing ratios from below 5 pptv (parts per trillion by volume) to greater than 100 pptv were reported, with the majority less than 20 pptv. Good correlation was observed between the measurements reported by the CL and LIF techniques. The general level of agreement observed for the ensemble of measurements obtained during the two missions provides the basis from which one can conclude that equally 'valid' measurements of background levels of NO can be expected from either CL or LIF instruments. At the same time the periods of disagreement that were observed between the CL and LIF instruments as well as between the two CL instruments highlight the difficulty of obtaining reliable measurements with NO mixing ratios in the 5-20 pptv range and emphasize the vigilance that should be maintained in future NO measurements.

The Pliocene Model Intercomparison Project - Phase 2

NASA Astrophysics Data System (ADS)

Haywood, Alan; Dowsett, Harry; Dolan, Aisling; Rowley, David; Abe-Ouchi, Ayako; Otto-Bliesner, Bette; Chandler, Mark; Hunter, Stephen; Lunt, Daniel; Pound, Matthew; Salzmann, Ulrich

2016-04-01

The Pliocene Model Intercomparison Project (PlioMIP) is a co-ordinated international climate modelling initiative to study and understand climate and environments of the Late Pliocene, and their potential relevance in the context of future climate change. PlioMIP examines the consistency of model predictions in simulating Pliocene climate, and their ability to reproduce climate signals preserved by geological climate archives. Here we provide a description of the aim and objectives of the next phase of the model intercomparison project (PlioMIP Phase 2), and we present the experimental design and boundary conditions that will be utilised for climate model experiments in Phase 2. Following on from PlioMIP Phase 1, Phase 2 will continue to be a mechanism for sampling structural uncertainty within climate models. However, Phase 1 demonstrated the requirement to better understand boundary condition uncertainties as well as uncertainty in the methodologies used for data-model comparison. Therefore, our strategy for Phase 2 is to utilise state-of-the-art boundary conditions that have emerged over the last 5 years. These include a new palaeogeographic reconstruction, detailing ocean bathymetry and land/ice surface topography. The ice surface topography is built upon the lessons learned from offline ice sheet modelling studies. Land surface cover has been enhanced by recent additions of Pliocene soils and lakes. Atmospheric reconstructions of palaeo-CO2 are emerging on orbital timescales and these are also incorporated into PlioMIP Phase 2. New records of surface and sea surface temperature change are being produced that will be more temporally consistent with the boundary conditions and forcings used within models. Finally we have designed a suite of prioritized experiments that tackle issues surrounding the basic understanding of the Pliocene and its relevance in the context of future climate change in a discrete way.

Field intercomparison of ammonia passive samplers: results and lessons learned.

NASA Astrophysics Data System (ADS)

Stephens, Amy; Leeson, Sarah; Jones, Matthew; van Dijk, Netty; Kentisbeer, John; Twigg, Marsailidh; Simmons, Ivan; Braban, Christine; Martin, Nick; Poskitt, Janet; Ferm, Martin; Seitler, Eva; Sacco, Paolo; Gates, Linda; Stolk, Ariën; Stoll, Jean-Marc; Tang, Sim

2017-04-01

Ammonia pollution contributes significantly to eutrophication and acidification of ecosystems with resultant losses of biodiversity and ecosystem changes. Monitoring of ambient ammonia over a wide spatial and long temporal scales is primarily done with low-cost diffusive samplers. Less frequently, surface flux measurements of ammonia can be made using passive samplers at plot scale. This paper will present a field intercomparison conducted within the MetNH3 project to assess the performance of passive samplers for ambient measurements of ammonia. Eight different designs of commercial passive samplers housed in shelters provided by the manufacturer/laboratory were exposed over an 8-week period at the Whim experimental field site in Scotland between August and October 2016. Whim Bog has a facility in place for controlled releases of ammonia (http://www.whimbog.ceh.ac.uk/). Automated conditional release from the line source occurs when the wind direction in the preceding minute is from the northeast (wind sector 180-215°) and wind speed is > 5 m s-1. The passive samplers were exposed at different distances from the release source (16, 32 and 60 m) and also at a background location. Most were exposed for 2 x 4-week long periods and some for 4 x 2-week long periods. At the 32 m position, an active denuder method, the CEH DELTA sampler and a continuous high temporal resolution wet chemistry ammonia instrument (AiRRmonia, Mechatronics, NL.) were also deployed alongside the passive samplers to provide reference measurements of ammonia. Results are presented within the context of the MetNH3 CATFAC controlled laboratory exposure assessments. The results are discussed in terms of typical deployments of passive samplers and quality control. Measurement for policy evidence for both local and regional studies using passive samplers are discussed.

VLBI Digital-Backend Intercomparison Test Report

NASA Technical Reports Server (NTRS)

Whitney, Alan; Beaudoin, Christopher; Cappallo, Roger; Niell, Arthur; Petrachenko, Bill; Ruszczyk, Chester A.; Titus, Mike

2013-01-01

Issues related to digital-backend (DBE) systems can be difficult to evaluate in either local tests or actual VLBI experiments. The 2nd DBE intercomparison workshop at Haystack Observatory on 25-26 October 2012 provided a forum to explicitly address validation and interoperability issues among independent global developers of DBE equipment. This special report discusses the workshop. It identifies DBE systems that were tested at the workshop, describes the test objectives and procedures, and reports and discusses the results of the testing.

Soot Particle Studies - Instrument Inter-Comparison – Project Overview

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cross, E.; Sedlacek, A.; Onasch, T. B.

2010-03-06

An inter-comparison study of instruments designed to measure the microphysical and optical properties of soot particles was completed. The following mass-based instruments were tested: Couette Centrifugal Particle Mass Analyzer (CPMA), Time-of-Flight Aerosol Mass Spectrometer - Scanning Mobility Particle Sizer (AMS-SMPS), Single Particle Soot Photometer (SP2), Soot Particle-Aerosol Mass Spectrometer (SP-AMS) and Photoelectric Aerosol Sensor (PAS2000CE). Optical instruments measured absorption (photoacoustic, interferometric, and filter-based), scattering (in situ), and extinction (light attenuation within an optical cavity). The study covered an experimental matrix consisting of 318 runs that systematically tested the performance of instruments across a range of parameters including: fuel equivalence ratiomore » (1.8 {le} {phi} {le} 5), particle shape (mass-mobility exponent (D{sub f m}), 2.0 {le} D{sub f m} {le} 3.0), particle mobility size (30 {le} d{sub m} {le} 300 nm), black carbon mass (0.07 {le} m{sub BC} {le} 4.2 fg) and particle chemical composition. In selected runs, particles were coated with sulfuric acid or dioctyl sebacate (DOS) (0.5 {le} {Delta}r{sub ve} {le} 201 nm) where {Delta}r{sub ve} is the change in the volume equivalent radius due to the coating material. The effect of non-absorbing coatings on instrument response was determined. Changes in the morphology of fractal soot particles were monitored during coating and denuding processes and the effect of particle shape on instrument response was determined. The combination of optical and mass based measurements was used to determine the mass specific absorption coefficient for denuded soot particles. The single scattering albedo of the particles was also measured. An overview of the experiments and sample results are presented.« less

The North American Carbon Program Multi-scale Synthesis and Terrestrial Model Intercomparison Project – Part 2: Environmental driver data

DOE PAGES

Wei, Yaxing; Liu, Shishi; Huntzinger, Deborah N.; ...

2014-12-05

Ecosystems are important and dynamic components of the global carbon cycle, and terrestrial biospheric models (TBMs) are crucial tools in further understanding of how terrestrial carbon is stored and exchanged with the atmosphere across a variety of spatial and temporal scales. Improving TBM skills, and quantifying and reducing their estimation uncertainties, pose significant challenges. The Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) is a formal multi-scale and multi-model intercomparison effort set up to tackle these challenges. The MsTMIP protocol prescribes standardized environmental driver data that are shared among model teams to facilitate model model and model observation comparisons. Inmore » this article, we describe the global and North American environmental driver data sets prepared for the MsTMIP activity to both support their use in MsTMIP and make these data, along with the processes used in selecting/processing these data, accessible to a broader audience. Based on project needs and lessons learned from past model intercomparison activities, we compiled climate, atmospheric CO 2 concentrations, nitrogen deposition, land use and land cover change (LULCC), C3 / C4 grasses fractions, major crops, phenology and soil data into a standard format for global (0.5⁰ x 0.5⁰ resolution) and regional (North American: 0.25⁰ x 0.25⁰ resolution) simulations. In order to meet the needs of MsTMIP, improvements were made to several of the original environmental data sets, by improving the quality, and/or changing their spatial and temporal coverage, and resolution. The resulting standardized model driver data sets are being used by over 20 different models participating in MsTMIP. Lastly, the data are archived at the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC, http://daac.ornl.gov) to provide long-term data management and distribution.« less

Total ozone measurement: Intercomparison of prototype New Zealand filter instrument and Dobson spectrophotometer

NASA Technical Reports Server (NTRS)

Basher, R. E.

1978-01-01

A five month intercomparison showed that the total ozone amounts of a prototype narrowband interference filter instrument were 7% less than those of a Dobson instrument for an ozone range of 0.300 to 0.500 atm cm and for airmasses less than two. The 7% bias was within the intercomparison calibration uncertainty. An airmass dependence in the Dobson instrument made the bias relationship airmass-dependent but the filter instrument's ozone values were generally constant to 2% up to an airmass of four. Long term drift in the bias was negligible.

An overview of sensor calibration inter-comparison and applications

USGS Publications Warehouse

Xiong, Xiaoxiong; Cao, Changyong; Chander, Gyanesh

2010-01-01

Long-term climate data records (CDR) are often constructed using observations made by multiple Earth observing sensors over a broad range of spectra and a large scale in both time and space. These sensors can be of the same or different types operated on the same or different platforms. They can be developed and built with different technologies and are likely operated over different time spans. It has been known that the uncertainty of climate models and data records depends not only on the calibration quality (accuracy and stability) of individual sensors, but also on their calibration consistency across instruments and platforms. Therefore, sensor calibration inter-comparison and validation have become increasingly demanding and will continue to play an important role for a better understanding of the science product quality. This paper provides an overview of different methodologies, which have been successfully applied for sensor calibration inter-comparison. Specific examples using different sensors, including MODIS, AVHRR, and ETM+, are presented to illustrate the implementation of these methodologies.

Intercomparison of Global Precipitation Products: The Third Precipitation Intercomparison Project (PIP-3)

NASA Technical Reports Server (NTRS)

Adler, Robert F.; Kidd, Christopher; Petty, Grant; Morrissey, Mark; Goodman, H. Michael; Einaudi, Franco (Technical Monitor)

2000-01-01

A set of global, monthly rainfall products has been intercompared to understand the quality and utility of the estimates. The products include 25 observational (satellite-based), four model and two climatological products. The results of the intercomparison indicate a very large range (factor of two or three) of values when all products are considered. The range of values is reduced considerably when the set of observational products is limited to those considered quasi-standard. The model products do significantly poorer in the tropics, but are competitive with satellite-based fields in mid-latitudes over land. Over ocean, products are compared to frequency of precipitation from ship observations. The evaluation of the observational products point to merged data products (including rain gauge information) as providing the overall best results.

The 1996 North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers

PubMed Central

Early, Edward; Thompson, Ambler; Johnson, Carol; DeLuisi, John; Disterhoft, Patrick; Wardle, David; Wu, Edmund; Mou, Wanfeng; Ehramjian, James; Tusson, John; Mestechkina, Tanya; Beaubian, Mark; Gibson, James; Hayes, Douglass

1998-01-01

Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. To assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks, the third North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers was held June 17–25, 1996 at Table Mountain outside Boulder, Colorado, USA. This Intercomparison was coordinated by the National Institute of Standards and Technology (NIST) and the National Oceanic and Atmospheric Administration (NOAA). Participating agencies were the Environmental Protection Agency; the National Science Foundation; the Smithsonian Environmental Research Center; the Department of Agriculture; and the Atmospheric Environment Service, Canada. The spectral irradiances of participants’ calibrated standard lamps were measured at NIST prior to the Intercomparison. The spectral irradiance scales used by the participants agreed with the NIST scale within the combined uncertainties, and for all lamps the spectral irradiance in the horizontal position was lower than that in the vertical position. Instruments were characterized for wavelength uncertainty, bandwidth, stray-light rejection, and spectral irradiance responsivity, the latter with NIST standard lamps operating in specially designed field calibration units. The spectral irradiance responsivity demonstrated instabilities for some instruments. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST standard lamps, the measured solar irradiances had some unexplained systematic differences between instruments. PMID:28009358

The T-REX valley wind intercomparison project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidli, J; Billings, B J; Burton, R

2008-08-07

An accurate simulation of the evolution of the atmospheric boundary layer is very important, as the evolution of the boundary layer sets the stage for many weather phenomena, such as deep convection. Over mountain areas the evolution of the boundary layer is particularly complex, due to the nonlinear interaction between boundary layer turbulence and thermally-induced mesoscale wind systems, such as the slope and valley winds. As the horizontal resolution of operational forecasts progresses to finer and finer resolution, more and more of the thermally-induced mesoscale wind systems can be explicitly resolved, and it is very timely to document the currentmore » state-of-the-art of mesoscale models at simulating the coupled evolution of the mountain boundary layer and the valley wind system. In this paper we present an intercomparison of valley wind simulations for an idealized valley-plain configuration using eight state-of-the-art mesoscale models with a grid spacing of 1 km. Different sets of three-dimensional simulations are used to explore the effects of varying model dynamical cores and physical parameterizations. This intercomparison project was conducted as part of the Terrain-induced Rotor Experiment (T-REX; Grubisic et al., 2008).« less

An intercomparison of carbon monoxide, nitric oxide, and hydroxyl measurement techniques - Overview of results

NASA Technical Reports Server (NTRS)

Hoell, J. M.; Gregory, G. L.; Carroll, M. A.; Mcfarland, M.; Ridley, B. A.; Davis, D. D.; Bradshaw, J.; Rodgers, M. O.; Torres, A. L.; Condon, E. P.

1984-01-01

Results from an intercomparison of methods to measure carbon monoxide (CO), nitric oxide (NO), and the hydroxyl radical (OH) are discussed. The intercomparison was conducted at Wallops Island, Virginia, in July 1983 and included a laser differential absorption and three grab sample/gas chromatograph methods for CO, a laser-induced fluorescence (LIF) and two chemiluminescence methods for NO, and two LIF methods and a radiocarbon tracer method for OH. The intercomparison was conducted as a field measurement program involving ambient measurements of CO (150-300 ppbv) and NO (10-180 pptv) from a common manifold with controlled injection of CO in incremental steps from 20 to 500 ppbv and NO in steps from 10 to 220 pptv. Only ambient measurements of OH were made. The agreement between the techniques was on the order of 14 percent for CO and 17 percent for NO. Hardware difficulties during the OH tests resulted in a data base with insufficient data and uncertanties too large to permit a meaningful intercomposition.

Global Intercomparison of 12 Land Surface Heat Flux Estimates

NASA Technical Reports Server (NTRS)

Jimenez, C.; Prigent, C.; Mueller, B.; Seneviratne, S. I.; McCabe, M. F.; Wood, E. F.; Rossow, W. B.; Balsamo, G.; Betts, A. K.; Dirmeyer, P. A.;

Intercomparison and interpretation of climate feedback processes in 19 atmospheric general circulation models

NASA Technical Reports Server (NTRS)

Cess, R. D.; Potter, G. L.; Blanchet, J. P.; Boer, G. J.; Del Genio, A. D.

1990-01-01

The present study provides an intercomparison and interpretation of climate feedback processes in 19 atmospheric general circulation models. This intercomparison uses sea surface temperature change as a surrogate for climate change. The interpretation of cloud-climate interactions is given special attention. A roughly threefold variation in one measure of global climate sensitivity is found among the 19 models. The important conclusion is that most of this variation is attributable to differences in the models' depiction of cloud feedback, a result that emphasizes the need for improvements in the treatment of clouds in these models if they are ultimately to be used as reliable climate predictors. It is further emphazied that cloud feedback is the consequence of all interacting physical and dynamical processes in a general circulation model. The result of these processes is to produce changes in temperature, moisture distribution, and clouds which are integrated into the radiative response termed cloud feedback.

Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison

NASA Astrophysics Data System (ADS)

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin; Beckley, Matthew; Abe-Ouchi, Ayako; Aschwanden, Andy; Calov, Reinhard; Gagliardini, Olivier; Gillet-Chaulet, Fabien; Golledge, Nicholas R.; Gregory, Jonathan; Greve, Ralf; Humbert, Angelika; Huybrechts, Philippe; Kennedy, Joseph H.; Larour, Eric; Lipscomb, William H.; Le clec'h, Sébastien; Lee, Victoria; Morlighem, Mathieu; Pattyn, Frank; Payne, Antony J.; Rodehacke, Christian; Rückamp, Martin; Saito, Fuyuki; Schlegel, Nicole; Seroussi, Helene; Shepherd, Andrew; Sun, Sainan; van de Wal, Roderik; Ziemen, Florian A.

2018-04-01

Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. The goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within the Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.

Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison

DOE PAGES

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin; ...

2018-04-19

Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. Here, the goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within themore » Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.« less

Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin

Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. Here, the goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within themore » Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.« less

International Intercomparison of Specific Absorption Rates in a Flat Absorbing Phantom in the Near-Field of Dipole Antennas

PubMed Central

Davis, Christopher C.; Beard, Brian B.; Tillman, Ahlia; Rzasa, John; Merideth, Eric; Balzano, Quirino

2018-01-01

This paper reports the results of an international intercomparison of the specific absorption rates (SARs) measured in a flat-bottomed container (flat phantom), filled with human head tissue simulant fluid, placed in the near-field of custom-built dipole antennas operating at 900 and 1800 MHz, respectively. These tests of the reliability of experimental SAR measurements have been conducted as part of a verification of the ways in which wireless phones are tested and certified for compliance with safety standards. The measurements are made using small electric-field probes scanned in the simulant fluid in the phantom to record the spatial SAR distribution. The intercomparison involved a standard flat phantom, antennas, power meters, and RF components being circulated among 15 different governmental and industrial laboratories. At the conclusion of each laboratory’s measurements, the following results were communicated to the coordinators: Spatial SAR scans at 900 and 1800 MHz and 1 and 10 g maximum spatial SAR averages for cubic volumes at 900 and 1800 MHz. The overall results, given as meanstandard deviation, are the following: at 900 MHz, 1 g average 7.850.76; 10 g average 5.160.45; at 1800 MHz, 1 g average 18.44 ± 1.65; 10 g average 10.14 ± 0.85, all measured in units of watt per kilogram, per watt of radiated power. PMID:29520117

GEOS observation systems intercomparison investigation results

NASA Technical Reports Server (NTRS)

Berbert, J. H.

1974-01-01

The results of an investigation designed to determine the relative accuracy and precision of the different types of geodetic observation systems used by NASA is presented. A collocation technique was used to minimize the effects of uncertainties in the relative station locations and in the earth's gravity field model by installing accurate reference tracking systems close to the systems to be compared, and by precisely determining their relative survey. The Goddard laser and camera systems were shipped to selected sites, where they tracked the GEOS satellite simultaneously with other systems for an intercomparison observation.

The Radiative Forcing Model Intercomparison Project (RFMIP): Assessment and characterization of forcing to enable feedback studies

NASA Astrophysics Data System (ADS)

Pincus, R.; Stevens, B. B.; Forster, P.; Collins, W.; Ramaswamy, V.

2014-12-01

The Radiative Forcing Model Intercomparison Project (RFMIP): Assessment and characterization of forcing to enable feedback studies An enormous amount of attention has been paid to the diversity of responses in the CMIP and other multi-model ensembles. This diversity is normally interpreted as a distribution in climate sensitivity driven by some distribution of feedback mechanisms. Identification of these feedbacks relies on precise identification of the forcing to which each model is subject, including distinguishing true error from model diversity. The Radiative Forcing Model Intercomparison Project (RFMIP) aims to disentangle the role of forcing from model sensitivity as determinants of varying climate model response by carefully characterizing the radiative forcing to which such models are subject and by coordinating experiments in which it is specified. RFMIP consists of four activities: 1) An assessment of accuracy in flux and forcing calculations for greenhouse gases under past, present, and future climates, using off-line radiative transfer calculations in specified atmospheres with climate model parameterizations and reference models 2) Characterization and assessment of model-specific historical forcing by anthropogenic aerosols, based on coordinated diagnostic output from climate models and off-line radiative transfer calculations with reference models 3) Characterization of model-specific effective radiative forcing, including contributions of model climatology and rapid adjustments, using coordinated climate model integrations and off-line radiative transfer calculations with a single fast model 4) Assessment of climate model response to precisely-characterized radiative forcing over the historical record, including efforts to infer true historical forcing from patterns of response, by direct specification of non-greenhouse-gas forcing in a series of coordinated climate model integrations This talk discusses the rationale for RFMIP, provides an overview

Intercomparison of Operational Ocean Forecasting Systems in the framework of GODAE

NASA Astrophysics Data System (ADS)

Hernandez, F.

2009-04-01

One of the main benefits of the GODAE 10-year activity is the implementation of ocean forecasting systems in several countries. In 2008, several systems are operated routinely, at global or basin scale. Among them, the BLUElink (Australia), HYCOM (USA), MOVE/MRI.COM (Japan), Mercator (France), FOAM (United Kingdom), TOPAZ (Norway) and C-NOOFS (Canada) systems offered to demonstrate their operational feasibility by performing an intercomparison exercise during a three months period (February to April 2008). The objectives were: a) to show that operational ocean forecasting systems are operated routinely in different countries, and that they can interact; b) to perform in a similar way a scientific validation aimed to assess the quality of the ocean estimates, the performance, and forecasting capabilities of each system; and c) to learn from this intercomparison exercise to increase inter-operability and collaboration in real time. The intercomparison relies on the assessment strategy developed for the EU MERSEA project, where diagnostics over the global ocean have been revisited by the GODAE contributors. This approach, based on metrics, allow for each system: a) to verify if ocean estimates are consistent with the current general knowledge of the dynamics; and b) to evaluate the accuracy of delivered products, compared to space and in-situ observations. Using the same diagnostics also allows one to intercompare the results from each system consistently. Water masses and general circulation description by the different systems are consistent with WOA05 Levitus climatology. The large scale dynamics (tropical, subtropical and subpolar gyres ) are also correctly reproduced. At short scales, benefit of high resolution systems can be evidenced on the turbulent eddy field, in particular when compared to eddy kinetic energy deduced from satellite altimetry of drifter observations. Comparisons to high resolution SST products show some discrepancies on ocean surface

Evaluation of Intercomparisons of Four Different Types of Model Simulating TWP-ICE

NASA Technical Reports Server (NTRS)

Petch, Jon; Hill, Adrian; Davies, Laura; Fridlind, Ann; Jakob, Christian; Lin, Yanluan; Xie, Shaoecheng; Zhu, Ping

2013-01-01

Four model intercomparisons were run and evaluated using the TWP-ICE field campaign, each involving different types of atmospheric model. Here we highlight what can be learnt from having single-column model (SCM), cloud-resolving model (CRM), global atmosphere model (GAM) and limited-area model (LAM) intercomparisons all based around the same field campaign. We also make recommendations for anyone planning further large multi-model intercomparisons to ensure they are of maximum value to the model development community. CRMs tended to match observations better than other model types, although there were exceptions such as outgoing long-wave radiation. All SCMs grew large temperature and moisture biases and performed worse than other model types for many diagnostics. The GAMs produced a delayed and significantly reduced peak in domain-average rain rate when compared to the observations. While it was shown that this was in part due to the analysis used to drive these models, the LAMs were also driven by this analysis and did not have the problem to the same extent. Based on differences between the models with parametrized convection (SCMs and GAMs) and those without (CRMs and LAMs), we speculate that that having explicit convection helps to constrain liquid water whereas the ice contents are controlled more by the representation of the microphysics.

The Southern Ocean in the Coupled Model Intercomparison Project phase 5

PubMed Central

Meijers, A. J. S.

2014-01-01

The Southern Ocean is an important part of the global climate system, but its complex coupled nature makes both its present state and its response to projected future climate forcing difficult to model. Clear trends in wind, sea-ice extent and ocean properties emerged from multi-model intercomparison in the Coupled Model Intercomparison Project phase 3 (CMIP3). Here, we review recent analyses of the historical and projected wind, sea ice, circulation and bulk properties of the Southern Ocean in the updated Coupled Model Intercomparison Project phase 5 (CMIP5) ensemble. Improvements to the models include higher resolutions, more complex and better-tuned parametrizations of ocean mixing, and improved biogeochemical cycles and atmospheric chemistry. CMIP5 largely reproduces the findings of CMIP3, but with smaller inter-model spreads and biases. By the end of the twenty-first century, mid-latitude wind stresses increase and shift polewards. All water masses warm, and intermediate waters freshen, while bottom waters increase in salinity. Surface mixed layers shallow, warm and freshen, whereas sea ice decreases. The upper overturning circulation intensifies, whereas bottom water formation is reduced. Significant disagreement exists between models for the response of the Antarctic Circumpolar Current strength, for reasons that are as yet unclear. PMID:24891395

The Community Intercomparison Suite (CIS)

NASA Astrophysics Data System (ADS)

Watson-Parris, Duncan; Schutgens, Nick; Cook, Nick; Kipling, Zak; Kershaw, Phil; Gryspeerdt, Ed; Lawrence, Bryan; Stier, Philip

2017-04-01

Earth observations (both remote and in-situ) create vast amounts of data providing invaluable constraints for the climate science community. Efficient exploitation of these complex and highly heterogeneous datasets has been limited however by the lack of suitable software tools, particularly for comparison of gridded and ungridded data, thus reducing scientific productivity. CIS (http://cistools.net) is an open-source, command line tool and Python library which allows the straight-forward quantitative analysis, intercomparison and visualisation of remote sensing, in-situ and model data. The CIS can read gridded and ungridded remote sensing, in-situ and model data - and many other data sources 'out-of-the-box', such as ESA Aerosol and Cloud CCI product, MODIS, Cloud CCI, Cloudsat, AERONET. Perhaps most importantly however CIS also employs a modular plugin architecture to allow for the reading of limitless different data types. Users are able to write their own plugins for reading the data sources which they are familiar with, and share them within the community, allowing all to benefit from their expertise. To enable the intercomparison of this data the CIS provides a number of operations including: the aggregation of ungridded and gridded datasets to coarser representations using a number of different built in averaging kernels; the subsetting of data to reduce its extent or dimensionality; the co-location of two distinct datasets onto a single set of co-ordinates; the visualisation of the input or output data through a number of different plots and graphs; the evaluation of arbitrary mathematical expressions against any number of datasets; and a number of other supporting functions such as a statistical comparison of two co-located datasets. These operations can be performed efficiently on local machines or large computing clusters - and is already available on the JASMIN computing facility. A case-study using the GASSP collection of in-situ aerosol observations

ATHLI16: the ATHens Lidar Intercomparison campaign

NASA Astrophysics Data System (ADS)

Amodeo, Aldo; D'Amico, Giuseppe; Giunta, Aldo; Papagiannopoulos, Nikolaos; Papayannis, Alex; Argyrouli, Athina; Mylonaki, Maria; Tsaknakis, Georgios; Kokkalis, Panos; Soupiona, Ourania; Tzanis, Chris

2018-04-01

The results of the ATHLI16 (ATHens Lidar Intercomparison) campaign, held in Athens from 26/09 to 07/10 2016 are presented. The campaign was performed within the Lidar Calibration Centre activities (EU H2020 ACTRIS-2 project) to assess the performance of the EOLE lidar system (NTUA, Athens, Greece), operating within EARLINET, by comparing against the EARLINET reference lidar system MUSA (CNR-IMAA, Potenza, Italy). For both lidars only products retrieved by the EARLINET Single Calculus Chain have been compared.

Results of the eruptive column model inter-comparison study

USGS Publications Warehouse

Costa, Antonio; Suzuki, Yujiro; Cerminara, M.; Devenish, Ben J.; Esposti Ongaro, T.; Herzog, Michael; Van Eaton, Alexa; Denby, L.C.; Bursik, Marcus; de' Michieli Vitturi, Mattia; Engwell, S.; Neri, Augusto; Barsotti, Sara; Folch, Arnau; Macedonio, Giovanni; Girault, F.; Carazzo, G.; Tait, S.; Kaminski, E.; Mastin, Larry G.; Woodhouse, Mark J.; Phillips, Jeremy C.; Hogg, Andrew J.; Degruyter, Wim; Bonadonna, Costanza

2016-01-01

This study compares and evaluates one-dimensional (1D) and three-dimensional (3D) numerical models of volcanic eruption columns in a set of different inter-comparison exercises. The exercises were designed as a blind test in which a set of common input parameters was given for two reference eruptions, representing a strong and a weak eruption column under different meteorological conditions. Comparing the results of the different models allows us to evaluate their capabilities and target areas for future improvement. Despite their different formulations, the 1D and 3D models provide reasonably consistent predictions of some of the key global descriptors of the volcanic plumes. Variability in plume height, estimated from the standard deviation of model predictions, is within ~ 20% for the weak plume and ~ 10% for the strong plume. Predictions of neutral buoyancy level are also in reasonably good agreement among the different models, with a standard deviation ranging from 9 to 19% (the latter for the weak plume in a windy atmosphere). Overall, these discrepancies are in the range of observational uncertainty of column height. However, there are important differences amongst models in terms of local properties along the plume axis, particularly for the strong plume. Our analysis suggests that the simplified treatment of entrainment in 1D models is adequate to resolve the general behaviour of the weak plume. However, it is inadequate to capture complex features of the strong plume, such as large vortices, partial column collapse, or gravitational fountaining that strongly enhance entrainment in the lower atmosphere. We conclude that there is a need to more accurately quantify entrainment rates, improve the representation of plume radius, and incorporate the effects of column instability in future versions of 1D volcanic plume models.

The Second Cabauw Intercomparison of Nitrogen Dioxide Measuring Instruments (CINDI-2)

NASA Astrophysics Data System (ADS)

Van Roozendael, M.; Hendrick, F.; Apituley, A.; Kreher, K.; Friess, U.; Richter, A.; Wagner, T.; Fehr, T.

2017-12-01

For the validation of space borne UV-Vis observations of air quality gases, ground based remote-sensing instruments using the MAXDOAS technique are an excellent choice, since they rely on similar retrieval techniques as the observations from orbit. Over the last decade, MAXDOAS instruments of various designs (including PANDORA systems) have been deployed worldwide forming the basis for a global ground based reference network suitable for the validation of future satellite sensors, such as TROPOMI/Sentinel-5 precursor, GEMS, TEMPO, and Sentinel 4 and 5. To ensure proper traceability of these observations, assess their accuracy and progress towards harmonized data acquisition and delivery, a thorough intercomparison campaign known as the Second Cabauw Intercomparison of Nitrogen Dioxide Measuring Instruments (CINDI-2) was held in Cabauw, The Netherlands during the month of September 2016. About 35 MAXDOAS instruments operated by 25 different groups were deployed, together with systems providing key ancillary in-situ measurements of NO2 and aerosol optical properties, as well as vertical profiles of NO2 by lidar and sonde and vertical profiles of aerosol optical properties by Raman lidar. We provide an overview of the main outcome of the campaign, which included a formal semi-blind slant column intercomparison and a number of additional exercises aiming at assessing the potential of the MAXDOAS technique for retrieving vertically-resolved information on NO2, aerosol, HCHO, O3 and a few other more challenging species such as HONO and glyoxal.

Quantitative trace analysis of polyfluorinated alkyl substances (PFAS) in ambient air samples from Mace Head (Ireland): A method intercomparison

NASA Astrophysics Data System (ADS)

Jahnke, Annika; Barber, Jonathan L.; Jones, Kevin C.; Temme, Christian

A method intercomparison study of analytical methods for the determination of neutral, volatile polyfluorinated alkyl substances (PFAS) was carried out in March, 2006. Environmental air samples were collected in triplicate at the European background site Mace Head on the west coast of Ireland, a site dominated by 'clean' westerly winds coming across the Atlantic. Extraction and analysis were performed at two laboratories active in PFAS research using their in-house methods. Airborne polyfluorinated telomer alcohols (FTOHs), fluorooctane sulfonamides and sulfonamidoethanols (FOSAs/FOSEs) as well as additional polyfluorinated compounds were investigated. Different native and isotope-labelled internal standards (IS) were applied at various steps in the analytical procedure to evaluate the different quantification strategies. Field blanks revealed no major blank problems. European background concentrations observed at Mace Head were found to be in a similar range to Arctic data reported in the literature. Due to trace-levels at the remote site, only FTOH data sets were complete and could therefore be compared between the laboratories. Additionally, FOSEs could partly be included. Data comparison revealed that despite the challenges inherent in analysis of airborne PFAS and the low concentrations, all methods applied in this study obtained similar results. However, application of isotope-labelled IS early in the analytical procedure leads to more precise results and is therefore recommended.

Crustal dynamics project session 4 validation and intercomparison experiments 1979-1980 report

NASA Technical Reports Server (NTRS)

Liebrecht, P.; Kolenkiewicz, R.; Ryan, J.; Hothem, L.

1983-01-01

As part of the Crustal Dynamics Project, an experiment was performed to verify the ability of Satellite Laser Ranging (SLR), Very Long Baseline interferometry (VLBI) and Doppler Satellite Positioning System (Doppler) techniques to estimate the baseline distances between several locations. The Goddard Space Flight Center (GSFC) lasers were in operation at all five sites available to them. The ten baselines involved were analyzed using monthly orbits and various methods of selecting data. The standard deviation of the monthly SLR baseline lengths was at the 7 cm level. The GSFC VLBI (Mark III) data was obtained during three separate experiments. November 1979 at Haystack and Owens Valley, and April and July 1980 at Haystack, Owens Valley, and Fort Davis. Repeatability of the VLBI in determining baseline lengths was calculated to be at the 2 cm level. Jet Propulsion Laboratory (JPL) VLBI (Mark II) data was acquired on the Owens Valley to Goldstone baseline on ten occasions between August 1979 and November 1980. The repeatability of these baseline length determinations was calculated to be at the 5 cm level. National Geodetic Survey (NGS) Doppler data was acquired at all five sites in January 1980. Repeatability of the Doppler determined baseline lengths results were calculated at approximately 30 cm. An intercomparison between baseline distances and associated parameters was made utilizing SLR, VLBI, and Doppler results on all available baselines. The VLBI and SLR length determinations were compared on four baselines with a resultant mean difference of -1 cm and a maximum difference of 12 cm. The SLR and Doppler length determinations were compared on ten baselines with a resultant mean difference of about 30 cm and a maximum difference of about 60 cm. The VLBI and Doppler lengths from seven baselines showed a resultant mean difference of about 30 cm and maximum difference of about 1 meter. The intercomparison of baseline orientation parameters were consistent with

Radiance and Jacobian Intercomparison of Radiative Transfer Models Applied to HIRS and AMSU Channels

NASA Technical Reports Server (NTRS)

Garand, L.; Turner, D. S.; Larocque, M.; Bates, J.; Boukabara, S.; Brunel, P.; Chevallier, F.; Deblonde, G.; Engelen, R.; Hollingshead, M.;

Radiance and Jacobian Intercomparison of Radiative Transfer Models Applied to HIRS and AMSU Channels

NASA Technical Reports Server (NTRS)

Garand, L.; Turner, D. S.; Larocque, M.; Bates, J.; Boukabara, S.; Brunel, P.; Chevallier, F.; Deblonde, G.; Engelen, R.; Atlas, Robert (Technical Monitor)

2000-01-01

The goals of this study are the evaluation of current fast radiative transfer models (RTMs) and line-by-line (LBL) models. The intercomparison focuses on the modeling of 11 representative sounding channels routinely used at numerical weather prediction centers: seven HIRS (High-resolution Infrared Sounder) and four AMSU (Advanced Microwave Sounding Unit) channels. Interest in this topic was evidenced by the participation of 24 scientists from 16 institutions. An ensemble of 42 diverse atmospheres was used and results compiled for 19 infrared models and 10 microwave models, including several LBL RTMs. For the first time, not only radiances, but also Jacobians (of temperature, water vapor, and ozone) were compared to various LBL models for many channels. In the infrared, LBL models typically agree to within 0.05-0.15 K (standard deviation) in terms of top-of-the-atmosphere brightness temperature (BT). Individual differences up to 0.5 K still exist, systematic in some channels, and linked to the type of atmosphere in others. The best fast models emulate LBL BTs to within 0.25 K, but no model achieves this desirable level of success for all channels. The ozone modeling is particularly challenging. In the microwave, fast models generally do quite well against the LBL model to which they were tuned. However significant differences were noted among LBL models. Extending the intercomparison to the Jacobians proved very useful in detecting subtle and more obvious modeling errors. In addition, total and single gas optical depths were calculated, which provided additional insight on the nature of differences. Recommendations for future intercomparisons are suggested.

First results of the CINDI-2 semi-blind MAX-DOAS intercomparison

NASA Astrophysics Data System (ADS)

Kreher, Karin; van Roozendael, Michel; Hendrick, Francois; Apituley, Arnoud; Friess, Udo; Lampel, Johannes; Piters, Ankie; Richter, Andreas; Wagner, Thomas; Cindi-2 Participants, All

2017-04-01

The second Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI-2) took place at the Cabauw Experimental Site for Atmospheric Research (CESAR; Utrecht area, The Netherlands) from 25 August until 7 October 2016. The goals of this inter-comparison campaign are to support the creation of high-quality ground-based data sets (e.g. to provide reliable long-term time series for trend analysis and satellite data validation), to characterise and better understand the differences between a large number of MAX-DOAS and DOAS instruments and analysis methods, and to contribute to a harmonisation of the measurement settings and retrieval methods. During a time period of 17 days, from 12 to 28 September 2016, a formal semi-blind intercomparison was held following a detailed measurement protocol. The development of this protocol was based on the experience gained during the first CINDI campaign held in 2009 as well as more recent projects and campaigns such as the MADCAT campaign in Mainz, Germany, in 2013. Strong emphasis was put on the careful synchronisation of the measurement sequence and on exact alignment of the elevation angles using horizon scans and lamp measurements. In this presentation, we provide an overview and some highlights of the MAX-DOAS semi-blind intercomparison campaign. We will introduce the participating groups, their instruments and the measurement protocol details, and then summarize the campaign outcomes to date. The CINDI-2 data sets have been investigated using a range of diagnostics including comparisons of daily time series and relative differences between the data sets, regression analysis and correlation plots. The data products so far investigated are NO2 (nitrogen dioxide) in the UV and visible wavelength region, O4 (oxygen dimer) in the same two wavelength intervals, O3 (ozone) in the UV and visible wavelength region, HCHO (formaldehyde) and NO2 in an additional (smaller) wavelength range in the visible. The results

Aircraft to aircraft intercomparison during SEMAPHORE

NASA Astrophysics Data System (ADS)

Lambert, Dominique; Durand, Pierre

1998-10-01

During the Structure des Echanges Mer-Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale (SEMAPHORE) experiment, performed in the Azores region in 1993, two French research aircraft were simultaneously used for in situ measurements in the atmospheric boundary layer. We present the results obtained from one intercomparison flight between the two aircraft. The mean parameters generally agree well, although the temperature has to be slightly shifted in order to be in agreement for the two aircraft. A detailed comparison of the turbulence parameters revealed no bias. The agreement is good for variances and is satisfactory for fluxes and skewness. A thorough study of the errors involved in flux computation revealed that the greatest accuracy is obtained for latent heat flux. Errors in sensible heat flux are considerably greater, and the worst results are obtained for momentum flux. The latter parameter, however, is more accurate than expected from previous parameterizations.

Czech results at criticality dosimetry intercomparison 2002.

PubMed

Frantisek, Spurný; Jaroslav, Trousil

2004-01-01

Two criticality dosimetry systems were tested by Czech participants during the intercomparison held in Valduc, France, June 2002. The first consisted of the thermoluminescent detectors (TLDs) (Al-P glasses) and Si-diodes as passive neutron dosemeters. Second, it was studied to what extent the individual dosemeters used in the Czech routine personal dosimetry service can give a reliable estimation of criticality accident exposure. It was found that the first system furnishes quite reliable estimation of accidental doses. For routine individual dosimetry system, no important problems were encountered in the case of photon dosemeters (TLDs, film badge). For etched track detectors in contact with the 232Th or 235U-Al alloy, the track density saturation for the spark counting method limits the upper dose at approximately 1 Gy for neutrons with the energy >1 MeV.

SimilarityExplorer: A visual inter-comparison tool for multifaceted climate data

Treesearch

J. Poco; A. Dasgupta; Y. Wei; W. Hargrove; C. Schwalm; R. Cook; E. Bertini; C. Silva

2014-01-01

Inter-comparison and similarity analysis to gauge consensus among multiple simulation models is a critical visualization problem for understanding climate change patterns. Climate models, specifically, Terrestrial Biosphere Models (TBM) represent time and space variable ecosystem processes, for example, simulations of photosynthesis and respiration, using algorithms...

BRDF Characterization and Calibration Inter-Comparison between Terra MODIS, Aqua MODIS, and S-NPP VIIRS

NASA Technical Reports Server (NTRS)

Chang, Tiejun; Xiong, Xiaoxiong (Jack); Angal, Amit; Wu, Aisheng

2016-01-01

The inter-comparison of reflective solar bands (RSB) between Terra MODIS, Aqua MODIS, and SNPP VIIRS is very important for assessment of each instrument's calibration and to identify calibration improvements. One of the limitations of using their ground observations for the assessment is a lack of the simultaneous nadir overpasses (SNOs) over selected pseudo-invariant targets. In addition, their measurements over a selected Earth view target have significant difference in solar and view angles, and these differences magnify the effects of Bidirectional Reflectance Distribution Function (BRDF). In this work, an inter-comparison technique using a semi-empirical BRDF model is developed for reflectance correction. BRDF characterization requires a broad coverage of solar and view angles in the measurements over selected pseudo-invariant targets. Reflectance measurements over Libya 1, 2, and 4 desert sites from both the Aqua and Terra MODIS are regressed to a BRDF model with an adjustable coefficient accounting for the calibration difference between the two instruments. The BRDF coefficients for three desert sites for MODIS bands 1 to 9 are derived and the wavelength dependencies are presented. The analysis and inter-comparison are for MODIS bands 1 to 9 and VIIRS moderate resolution radiometric bands (M bands) M1, M2, M4, M5, M7, M8, M10 and imaging bands (I bands) I1-I3. Results show that the ratios from different sites are in good agreement. The ratios between Terra and Aqua MODIS from year 2003 to 2014 are presented. The inter-comparison between MODIS and VIIRS are analyzed for year 2014.

Sao Paulo Lightning Mapping Array (SP-LMA): Network Assessment and Analyses for Intercomparison Studies and GOES-R Proxy Activities

NASA Technical Reports Server (NTRS)

Bailey, J. C.; Blakeslee, R. J.; Carey, L. D.; Goodman, S. J.; Rudlosky, S. D.; Albrecht, R.; Morales, C. A.; Anselmo, E. M.; Neves, J. R.; Buechler, D. E.

2014-01-01

A 12 station Lightning Mapping Array (LMA) network was deployed during October 2011 in the vicinity of Sao Paulo, Brazil (SP-LMA) to contribute total lightning measurements to an international field campaign [CHUVA - Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GPM (GlobAl Precipitation Measurement)]. The SP-LMA was operational from November 2011 through March 2012 during the Vale do Paraiba campaign. Sensor spacing was on the order of 15-30 km, with a network diameter on the order of 40-50km. The SP-LMA provides good 3-D lightning mapping out to 150 km from the network center, with 2-D coverage considerably farther. In addition to supporting CHUVA science/mission objectives, the SP-LMA is supporting the generation of unique proxy data for the Geostationary Lightning Mapper (GLM) and Advanced Baseline Imager (ABI), on NOAA's Geostationary Operational Environmental Satellite-R (GOES-R: scheduled for a 2015 launch). These proxy data will be used to develop and validate operational algorithms so that they will be ready to use on "day1" following the GOES-R launch. As the CHUVA Vale do Paraiba campaign opportunity was formulated, a broad community-based interest developed for a comprehensive Lightning Location System (LLS) intercomparison and assessment study, leading to the participation and/or deployment of eight other ground-based networks and the space-based Lightning Imaging Sensor (LIS). The SP-LMA data is being intercompared with lightning observations from other deployed lightning networks to advance our understanding of the capabilities/contributions of each of these networks toward GLM proxy and validation activities. This paper addresses the network assessment including noise reduction criteria, detection efficiency estimates, and statistical and climatological (both temporal and spatially) analyses for intercomparison studies and GOES-R proxy activities.

The Continuous Intercomparison of Radiation Codes (CIRC): Phase I Cases

NASA Technical Reports Server (NTRS)

Oreopoulos, Lazaros; Mlawer, Eli; Delamere, Jennifer; Shippert, Timothy; Turner, David D.; Miller, Mark A.; Minnis, Patrick; Clough, Shepard; Barker, Howard; Ellingson, Robert

2007-01-01

CIRC aspires to be the successor to ICRCCM (Intercomparison of Radiation Codes in Climate Models). It is envisioned as an evolving and regularly updated reference source for GCM-type radiative transfer (RT) code evaluation with the principle goal to contribute in the improvement of RT parameterizations. CIRC is jointly endorsed by DOE's Atmospheric Radiation Measurement (ARM) program and the GEWEX Radiation Panel (GRP). CIRC's goal is to provide test cases for which GCM RT algorithms should be performing at their best, i.e, well characterized clear-sky and homogeneous, overcast cloudy cases. What distinguishes CIRC from previous intercomparisons is that its pool of cases is based on observed datasets. The bulk of atmospheric and surface input as well as radiative fluxes come from ARM observations as documented in the Broadband Heating Rate Profile (BBHRP) product. BBHRP also provides reference calculations from AER's RRTM RT algorithms that can be used to select the most optimal set of cases and to provide a first-order estimate of our ability to achieve radiative flux closure given the limitations in our knowledge of the atmospheric state.

Black Carbon Measurement Intercomparison during the 2017 Black Carbon Shootout

NASA Astrophysics Data System (ADS)

Shingler, T.; Moore, R.; Winstead, E.; Robinson, C. E.; Shook, M.; Crosbie, E.; Ziemba, L. D.; Thornhill, K. L., II; Sorooshian, A.; Anderson, B. E.

2017-12-01

The NASA Langley Aerosol Research Group (LARGE) provides multiple black carbon (BC) based aerosol particle measurements and engine emission factors for airborne and ground-based field campaigns and laboratory studies. These datasets are made available to the general public where accuracy is key to enable further use in environmental assessments, models, and validation studies. Studies are needed to establish the accuracy and precision of BC measurements of particles with varying physical properties using a variety of detection techniques. Work is also needed to develop calibration and correction schemes for new sensors and to link these measurements to heritage instruments on which our understanding of BC emissions and characteristics has been established. A BC measurement intercomparison was performed at Langley Research Center using particles generated from a mini-CAST (Jing) diffusion flame soot generator. The particles were passed to instruments measuring optical absorption, extinction, scattering and black carbon mass. Filter based measurements of optical absorption were performed using a PSAP (Radiance Research) and a TAP (BMI). Absorption was also measured using two photoacoustic based instruments: the MSS-plus (AVL) and PASS-3 (DMT). Measurements of aerosol extinction were performed using three CAPS PM-ex (Aerodyne Research) instruments at multiple wavelengths. Two Artium LII-300 units (standard and high-sensitivity) were used to measure black carbon mass via laser incandescence. Black carbon measurements were correlated to mass collected concurrently on a filter and analyzed by OC/EC analysis (Sunset Labs). Black carbon quantification measurements are analyzed between instruments to assess agreement between platforms using manufacturer's calibration settings as well as after calibrations performed to a single standard soot source (mini-CAST). Sampling was also performed from behind a Falcon aircraft at multiple thrust settings and downwind of runway at an

Operational overview of NASA GTE/CITE 1 airborne instrument intercomparisons - Carbon monoxide, nitric oxide, and hydroxyl instrumentation. [Global Tropospheric Experiment/Chemical Instrumentation Test and Evaluation

NASA Technical Reports Server (NTRS)

Beck, Sherwin M.; Bendura, Richard J.; Mcdougal, David S.; Hoell, James M., Jr.; Gregory, Gerald L.; Sachse, Glen W.; Hill, Gerald F.; Curfman, Howard J., Jr.; Torres, Arnold L.; Condon, Estelle P.

1987-01-01

An overview of the airborne intercomparisons of CO, NO, and OH instrumentation is presented in this first paper of the series on the NASA Global Tropospheric Experiment/Chemical Instrumentation Test and Evaluation (GTE/CITE 1). This paper provides the reader with background information about several important characteristics of the project. These include the overall objectives and approach, the measurements taken, the intercomparison protocol, aircraft platform, profiles of each aircraft flight, and the participants. A synopsis of the overall results of the CO, NO, and OH instrument intercomparisons is also included. Companion papers discuss the detailed results of the CO and NO intercomparison tests as well as pertinent scientific findings.

Practical methodological guide for hydrometric inter-laboratory organisation

NASA Astrophysics Data System (ADS)

Besson, David; Bertrand, Xavier

2015-04-01

Discharge measurements performed by the French governmental hydrometer team feed a national database. This data is available for general river flows knowkedge, flood forecasting, low water survey, statistical calculations flow, control flow regulatory and many other uses. Regularly checking the measurements quality and better quantifying its accuracy is therefore an absolute need. The practice of inter-laboratory comparison in hydrometry particularly developed during the last decade. Indeed, discharge measurement can not easily be linked to a standard. Therefore, on-site measurement accuracy control is very difficult. Inter-laboratory comparison is thus a practical solution to this issue. However, it needs some regulations in order to ease its practice and legitimize its results. To do so, the French government hydrometrics teams produced a practical methodological guide for hydrometric inter-laboratory organisation in destination of hydrometers community in view of ensure the harmonization of inter-laboratory comparison practices for different materials (ADCP, current meter on wadind rod or gauging van, tracer dilution, surface speed) and flow range (flood, low water). Ensure the results formalization and banking. The realisation of this practice guide is grounded on the experience of the governmental teams & their partners (or fellows), following existing approaches (Doppler group especially). The guide is designated to validate compliance measures and identify outliers : Hardware, methodological, environmental, or human. Inter-laboratory comparison provides the means to verify the compliance of the instruments (devices + methods + operators) and provides methods to determine an experimental uncertainty of the tested measurement method which is valid only for the site and the measurement conditions but does not address the calibration or periodic monitoring of the few materials. After some conceptual definitions, the guide describes the different stages of an

IPRT polarized radiative transfer model intercomparison project - Phase A

NASA Astrophysics Data System (ADS)

Emde, Claudia; Barlakas, Vasileios; Cornet, Céline; Evans, Frank; Korkin, Sergey; Ota, Yoshifumi; Labonnote, Laurent C.; Lyapustin, Alexei; Macke, Andreas; Mayer, Bernhard; Wendisch, Manfred

2015-10-01

The polarization state of electromagnetic radiation scattered by atmospheric particles such as aerosols, cloud droplets, or ice crystals contains much more information about the optical and microphysical properties than the total intensity alone. For this reason an increasing number of polarimetric observations are performed from space, from the ground and from aircraft. Polarized radiative transfer models are required to interpret and analyse these measurements and to develop retrieval algorithms exploiting polarimetric observations. In the last years a large number of new codes have been developed, mostly for specific applications. Benchmark results are available for specific cases, but not for more sophisticated scenarios including polarized surface reflection and multi-layer atmospheres. The International Polarized Radiative Transfer (IPRT) working group of the International Radiation Commission (IRC) has initiated a model intercomparison project in order to fill this gap. This paper presents the results of the first phase A of the IPRT project which includes ten test cases, from simple setups with only one layer and Rayleigh scattering to rather sophisticated setups with a cloud embedded in a standard atmosphere above an ocean surface. All scenarios in the first phase A of the intercomparison project are for a one-dimensional plane-parallel model geometry. The commonly established benchmark results are available at the IPRT website.

ISI-MIP: The Inter-Sectoral Impact Model Intercomparison Project

NASA Astrophysics Data System (ADS)

Huber, V.; Dahlemann, S.; Frieler, K.; Piontek, F.; Schewe, J.; Serdeczny, O.; Warszawski, L.

2013-12-01

The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) aims to synthesize the state-of-the-art knowledge of climate change impacts at different levels of global warming. The project's experimental design is formulated to distinguish the uncertainty introduced by the impact models themselves, from the inherent uncertainty in the climate projections and the variety of plausible socio-economic futures. The unique cross-sectoral scope of the project provides the opportunity to study cascading effects of impacts in interacting sectors and to identify regional 'hot spots' where multiple sectors experience extreme impacts. Another emphasis lies on the development of novel metrics to describe societal impacts of a warmer climate. We briefly outline the methodological framework, and then present selected results of the first, fast-tracked phase of ISI-MIP. The fast track brought together 35 global impact models internationally, spanning five sectors across human society and the natural world (agriculture, water, natural ecosystems, health and coastal infrastructure), and using the latest generation of global climate simulations (RCP projections from the CMIP5 archive) and socioeconomic drivers provided within the SSP process. We also introduce the second phase of the project, which will enlarge the scope of ISI-MIP by encompassing further impact sectors (e.g., forestry, fisheries, permafrost) and regional modeling approaches. The focus for the next round of simulations will be the validation and improvement of models based on historical observations and the analysis of variability and extreme events. Last but not least, we discuss the longer-term objective of ISI-MIP to initiate a coordinated, ongoing impact assessment process, driven by the entire impact community and in parallel with well-established climate model intercomparisons (CMIP).

Assessing agricultural risks of climate change in the 21st century in a global gridded crop model intercomparison

PubMed Central

Rosenzweig, Cynthia; Elliott, Joshua; Deryng, Delphine; Ruane, Alex C.; Müller, Christoph; Arneth, Almut; Boote, Kenneth J.; Folberth, Christian; Glotter, Michael; Khabarov, Nikolay; Neumann, Kathleen; Piontek, Franziska; Pugh, Thomas A. M.; Schmid, Erwin; Stehfest, Elke; Yang, Hong; Jones, James W.

2014-01-01

Here we present the results from an intercomparison of multiple global gridded crop models (GGCMs) within the framework of the Agricultural Model Intercomparison and Improvement Project and the Inter-Sectoral Impacts Model Intercomparison Project. Results indicate strong negative effects of climate change, especially at higher levels of warming and at low latitudes; models that include explicit nitrogen stress project more severe impacts. Across seven GGCMs, five global climate models, and four representative concentration pathways, model agreement on direction of yield changes is found in many major agricultural regions at both low and high latitudes; however, reducing uncertainty in sign of response in mid-latitude regions remains a challenge. Uncertainties related to the representation of carbon dioxide, nitrogen, and high temperature effects demonstrated here show that further research is urgently needed to better understand effects of climate change on agricultural production and to devise targeted adaptation strategies. PMID:24344314

Assessing Agricultural Risks of Climate Change in the 21st Century in a Global Gridded Crop Model Intercomparison

NASA Technical Reports Server (NTRS)

Rosenzweig, Cynthia E.; Elliott, Joshua; Deryng, Delphine; Ruane, Alex C.; Mueller, Christoph; Arneth, Almut; Boote, Kenneth J.; Folberth, Christian; Glotter, Michael; Khabarov, Nikolay

2014-01-01

Here we present the results from an intercomparison of multiple global gridded crop models (GGCMs) within the framework of the Agricultural Model Intercomparison and Improvement Project and the Inter-Sectoral Impacts Model Intercomparison Project. Results indicate strong negative effects of climate change, especially at higher levels of warming and at low latitudes; models that include explicit nitrogen stress project more severe impacts. Across seven GGCMs, five global climate models, and four representative concentration pathways, model agreement on direction of yield changes is found in many major agricultural regions at both low and high latitudes; however, reducing uncertainty in sign of response in mid-latitude regions remains a challenge. Uncertainties related to the representation of carbon dioxide, nitrogen, and high temperature effects demonstrated here show that further research is urgently needed to better understand effects of climate change on agricultural production and to devise targeted adaptation strategies.

FIELD INTERCOMPARISON OF SULFATE DRY DEPOSITION MONITORING AND MEASUREMENT METHODS: PRELIMINARY RESULTS

EPA Science Inventory

The Illinois State Water Survey hosted a three-week field intercomparison of several sulfate dry deposition measurement techniques during September 81. The site was an 80-acre grass field in a rural area 14 km southwest of Champaign, IL. The vegetation consisted of mixed grasses ...

Intercomparison of mid latitude storm diagnostics (IMILAST) - synthesis of project results

NASA Astrophysics Data System (ADS)

Neu, Urs

2017-04-01

The analysis of the occurrence of mid-latitude storms is of great socio-economical interest due to their vast and destructive impacts. However, a unique definition of cyclones is missing, and therefore the definition of what a cyclone is as well as quantifying its strength contains subjective choices. Existing automatic cyclone identification and tracking algorithms are based on different definitions and use diverse characteristics, e.g. data transformation, metrics used for cyclone identification, cyclone identification procedures or tracking methods. The project IMILAST systematically compares different cyclone detection and tracking methods, with the aim to comprehensively assess the influence of different algorithms on cyclone climatologies, temporal trends of frequency, strength or other characteristics of cyclones and thus quantify systematic uncertainties in mid-latitudinal storm identification and tracking. The three main intercomparison experiments used the ERA-interim reanalysis as a common input data set and focused on differences between the methods with respect to number, track density, life cycle characteristics, and trend patterns on the one hand and potential differences of the long-term climate change signal of cyclonic activity between the methods on the other hand. For the third experiment, the intercomparison period has been extended to a 30 year period from 1979 to 2009 and focuses on more specific aspects, such as parameter sensitivities, the comparison of automated to manual tracking sets, regional analysis (regional trends, Arctic and Antarctic cyclones, cyclones in the Mediterranean) or specific phenomena like splitting and merging of cyclones. In addition, the representation of storms and their characteristics in reanalysis data sets is examined to further enhance the knowledge on uncertainties related to storm occurrence. This poster presents a synthesis of the main results from the intercomparison activities within IMILAST.

Laboratory Governance: Issues for the Study Group on Regional Laboratories.

ERIC Educational Resources Information Center

Schultz, Thomas; Dominic, Joseph

Background information and an analysis of issues involved in the governance of new regional educational laboratories are presented. The new laboratories are to be established through a 1984 competition administered by the National Institute of Education (NIE). The analysis is designed to assist the Study Group on Regional Laboratories to advise…

NOAA National Status and Trends Program Twelfth Round Intercomparison Exercise Results for Trace Metals in Marine Sediments and Biological Tissues. National Status and Trends Program for marine environmental quality: Technical memo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willie, S.

1998-11-01

The report summarizes the results of the Twelfth Round Intercomparison for Trace Metals in Marine Sediments and Biological Tissues under the directive of the NOAA National Status and Trends Program. A total of forty-four participants were included in the exercise, including NOAA, USEPA, state, Austrailian, Canadian, Mexican and Argentinean laboratories. Two samples were sent by NRC to each participant, a marine sediment collected on the east coast of Canada and a freeze-dried mussel tissue. Laboratories were also asked to analyze two certified reference materials (CRMs) MESS-2 and CRM 2976. The elements to be determined were Al, Cr, Fe, Ni, Cu,more » Zn, As, Se, Ag, Cd, Sn, Hg, and Pb for both matrices, plus Be, Si, Mn, Sb, and Tl for the sediments. An accepted mean and confidence interval was calculated for each analyte in the two unknown samples, laboratory biases were identified and an overall rating of superior, good, fair or others were assigned to each laboratory.« less

Ice Sheet Model Intercomparison Project (ISMIP6) contribution to CMIP6

PubMed Central

Nowicki, Sophie M.J.; Payne, Tony; Larour, Eric; Seroussi, Helene; Goelzer, Heiko; Lipscomb, William; Gregory, Jonathan; Abe-Ouchi, Ayako; Shepherd, Andrew

2018-01-01

Reducing the uncertainty in the past, present and future contribution of ice sheets to sea-level change requires a coordinated effort between the climate and glaciology communities. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) is the primary activity within the Coupled Model Intercomparison Project – phase 6 (CMIP6) focusing on the Greenland and Antarctic Ice Sheets. In this paper, we describe the framework for ISMIP6 and its relationship to other activities within CMIP6. The ISMIP6 experimental design relies on CMIP6 climate models and includes, for the first time within CMIP, coupled ice sheet – climate models as well as standalone ice sheet models. To facilitate analysis of the multi-model ensemble and to generate a set of standard climate inputs for standalone ice sheet models, ISMIP6 defines a protocol for all variables related to ice sheets. ISMIP6 will provide a basis for investigating the feedbacks, impacts, and sea-level changes associated with dynamic ice sheets and for quantifying the uncertainty in ice-sheet-sourced global sea-level change. PMID:29697697

Ice Sheet Model Intercomparison Project (ISMIP6) Contribution to CMIP6

NASA Technical Reports Server (NTRS)

Nowicki, Sophie M. J.; Payne, Tony; Larour, Eric; Seroussi, Helene; Goelzer, Heiko; Lipscomb, William; Gregory, Jonathan; Abe-Ouchi, Ayako; Shepherd, Andrew

2016-01-01

Reducing the uncertainty in the past, present, and future contribution of ice sheets to sea-level change requires a coordinated effort between the climate and glaciology communities. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) is the primary activity within the Coupled Model Intercomparison Project phase 6 (CMIP6) focusing on the Greenland and Antarctic ice sheets. In this paper, we describe the framework for ISMIP6 and its relationship with other activities within CMIP6. The ISMIP6 experimental design relies on CMIP6 climate models and includes, for the first time within CMIP, coupled ice-sheetclimate models as well as standalone ice-sheet models. To facilitate analysis of the multi-model ensemble and to generate a set of standard climate inputs for standalone ice-sheet models, ISMIP6 defines a protocol for all variables related to ice sheets. ISMIP6 will provide a basis for investigating the feedbacks, impacts, and sea-level changes associated with dynamic ice sheets and for quantifying the uncertainty in ice-sheet-sourced global sea-level change.

Overview of Dust Model Inter-comparison (DMIP) in East Asia

NASA Astrophysics Data System (ADS)

Uno, I.

2004-12-01

Dust transport modeling plays an important role in understanding the recent increase of Asian Dust episodes and its impact to the regional climate system. Several dust models have been developed in several research institutes and government agencies independently since 1990s. Their numerical results either look very similar or different. Those disagreements are caused by difference in dust modules (concepts and basic mechanisms) and atmospheric models (meteorological and transport models). Therefore common understanding of performance and uncertainty of dust erosion and transport models in the Asian region becomes very important. To have a better understanding of dust model application, we proposed the dust model intercomparison under the international cooperation networks as a part of activity of ADEC (Aeolian Dust Experiment on Climate Impact) project research. Current participants are Kyusyu Univ. (Japan), Meteorological Research Institute (Japan), Hong-Kong City Univ. (China), Korean Meteorological Agency METRI (Korea), US Naval Research Laboratory (USA), Chinese Meteorological Agency (China), Institute of Atmospheric Physics (China), Insular Coastal Dynamics (Malta) and Meteorological Service of Canada (Canada). As a case study episode, we set two huge dust storms occurred in March and April 2002. Results from the dust transport model from all the participants are compiled on the same methods and examined the model characteristics against the ground and airborne measurement data. We will also examine the dust model results from the horizontal distribution at specified levels, vertical profiles, concentration at special check point and emission flux at source region, and show the important parameters for dust modeling. In this paper, we will introduce the general overview of this DMIP activity and several important conclusions from this activity.

Methods for Validation and Intercomparison of Remote Sensing and In situ Ice Water Measurements: Case Studies from CRYSTAL-FACE and Model Results

NASA Technical Reports Server (NTRS)

Sayres, D.S.; Pittman, J. V.; Smith, J. B.; Weinstock, E. M.; Anderson, J. G.; Heymsfield, G.; Li, L.; Fridlind, A.; Ackerman, A. S.

2004-01-01

Remote sensing observations, such as those from AURA, are necessary to understand the role of cirrus in determining the radiative and humidity budgets of the upper troposphere. Using these measurements quantitatively requires comparisons with in situ measurements that have previously been validated. However, a direct comparison of remote and in situ measurements is difficult due to the requirement that the spatial and temporal overlap be sufficient in order to guarantee that both instruments are measuring the same air parcel. A difficult as this might be for gas phase intercomparisons, cloud inhomogeneities significantly exacerbate the problem for cloud ice water content measurements. The CRYSTAL-FACE mission provided an opportunity to assess how well such intercomparisons can be performed and to establish flight plans that will be necessary for validation of future satellite instruments. During CRYSTAL-FACE, remote and in situ instruments were placed on different aircraft (NASA's ER-2 and WB-59, and the two planes flew in tandem so that the in situ payload flew in the field of view of the remote instruments. We show here that, even with this type of careful flight planning, it is not always possible to guarantee that remote and in situ instruments are viewing the same air parcel. We use ice water data derived from the in situ Harvard Total Water (HV-TW) instrument, and the remote Goddard Cloud Radar System (CRS) and show that agreement between HV-TW and CRS is a strong function of the horizontal separation and the time delay between the aircraft transects. We also use a cloud model to simulate possible trajectories through a cloud and evaluate the use of statistical analysis in determining the agreement between the two instruments. This type of analysis should guide flight planning for future intercomparison efforts, whether for aircraft or satellite-borne instrumentation.

Large-Scale Features of Pliocene Climate: Results from the Pliocene Model Intercomparison Project

NASA Technical Reports Server (NTRS)

Haywood, A. M.; Hill, D.J.; Dolan, A. M.; Otto-Bliesner, B. L.; Bragg, F.; Chan, W.-L.; Chandler, M. A.; Contoux, C.; Dowsett, H. J.; Jost, A.;

A protocol for the intercomparison of marine fishery and ecosystem models: Fish-MIP v1.0

NASA Astrophysics Data System (ADS)

Tittensor, Derek P.; Eddy, Tyler D.; Lotze, Heike K.; Galbraith, Eric D.; Cheung, William; Barange, Manuel; Blanchard, Julia L.; Bopp, Laurent; Bryndum-Buchholz, Andrea; Büchner, Matthias; Bulman, Catherine; Carozza, David A.; Christensen, Villy; Coll, Marta; Dunne, John P.; Fernandes, Jose A.; Fulton, Elizabeth A.; Hobday, Alistair J.; Huber, Veronika; Jennings, Simon; Jones, Miranda; Lehodey, Patrick; Link, Jason S.; Mackinson, Steve; Maury, Olivier; Niiranen, Susa; Oliveros-Ramos, Ricardo; Roy, Tilla; Schewe, Jacob; Shin, Yunne-Jai; Silva, Tiago; Stock, Charles A.; Steenbeek, Jeroen; Underwood, Philip J.; Volkholz, Jan; Watson, James R.; Walker, Nicola D.

2018-04-01

Model intercomparison studies in the climate and Earth sciences communities have been crucial to building credibility and coherence for future projections. They have quantified variability among models, spurred model development, contrasted within- and among-model uncertainty, assessed model fits to historical data, and provided ensemble projections of future change under specified scenarios. Given the speed and magnitude of anthropogenic change in the marine environment and the consequent effects on food security, biodiversity, marine industries, and society, the time is ripe for similar comparisons among models of fisheries and marine ecosystems. Here, we describe the Fisheries and Marine Ecosystem Model Intercomparison Project protocol version 1.0 (Fish-MIP v1.0), part of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP), which is a cross-sectoral network of climate impact modellers. Given the complexity of the marine ecosystem, this class of models has substantial heterogeneity of purpose, scope, theoretical underpinning, processes considered, parameterizations, resolution (grain size), and spatial extent. This heterogeneity reflects the lack of a unified understanding of the marine ecosystem and implies that the assemblage of all models is more likely to include a greater number of relevant processes than any single model. The current Fish-MIP protocol is designed to allow these heterogeneous models to be forced with common Earth System Model (ESM) Coupled Model Intercomparison Project Phase 5 (CMIP5) outputs under prescribed scenarios for historic (from the 1950s) and future (to 2100) time periods; it will be adapted to CMIP phase 6 (CMIP6) in future iterations. It also describes a standardized set of outputs for each participating Fish-MIP model to produce. This enables the broad characterization of differences between and uncertainties within models and projections when assessing climate and fisheries impacts on marine ecosystems and the

Model Intercomparison of CCN-Limited Arctic Clouds During ASCOS

NASA Astrophysics Data System (ADS)

Stevens, Robin; Dearden, Chris; Dimetrelos, Antonios; Eirund, Gesa; Possner, Anna; Raatikainen, Tomi; Loewe, Katharina; Hill, Adrian; Shipway, Ben; Connolly, Paul; Ekman, Annica; Hoose, Corinna; Laaksonen, Ari; de Leeuw, Gerrit; Kolmonen, Pekka; Saponaro, Giulia; Field, Paul; Carlsaw, Ken

2017-04-01

Future decreases in Arctic sea ice are expected to increase fluxes of aerosol and precursor gases from the open ocean surface within the Arctic. The resulting increase in cloud condensation nuclei (CCN) concentrations would be expected to result in increased cloud albedo (Struthers et al, 2011), leading to potentially large changes in radiative forcings. However, Browse et al. (2014) have shown that these increases in condensable material could also result in the growth of existing particles to sizes where they are more efficiently removed by wet deposition in drizzling stratocumulus clouds, ultimately decreasing CCN concentrations in the high Arctic. Their study was limited in that it did not simulate alterations of dynamics or cloud properties due to either changes in heat and moisture fluxes following sea­-ice loss or changing aerosol concentrations. Taken together, these results show that significant uncertainties remain in trying to quantify aerosol­-cloud processes in the Arctic system. The current representation of these processes in global climate models is most likely insufficient to realistically simulate long­-term changes. In order to better understand the microphysical processes currently governing Arctic clouds, we perform a model intercomparison of summertime high Arctic (>80N) clouds observed during the 2008 ASCOS campaign. The intercomparison includes results from three large eddy simulation models (UCLALES-SALSA, COSMO-LES, and MIMICA) and three numerical weather prediction models (COSMO-NWP, WRF, and UM-CASIM). The results of these experiments will be used as a basis for sensitivity studies on the impact of sea-ice loss on Arctic clouds through changes in aerosol and precursor emissions as well as changes in latent and sensible heat fluxes. Browse, J., et al., Atmos. Chem. Phys., 14(14), 7543-7557, doi:10.5194/acp-14-7543-2014, 2014. Struthers, H., et al., Atmos. Chem. Phys., 11(7), 3459-3477, doi:10.5194/acp-11-3459-2011, 2011.

Intercomparison of different operational oceanographic forecast products in the CMEMS IBI area

NASA Astrophysics Data System (ADS)

Lorente, Pablo; Sotillo, Marcos G.; Dabrowski, Tomasz; Amo-Baladrón, Arancha; Aznar, Roland; De Pascual, Alvaro; Levier, Bruno; Bowyer, Peter; Cossarini, Gianpiero; Salon, Stefano; Tonani, Marina; Alvarez-Fanjul, Enrique

2017-04-01

The development of skill assessment software packages and dedicated web applications is a relatively novel theme in operational oceanography. Within the CMEMS IBI-MFC, the quality of IBI (Iberia-Biscay-Ireland) forecast products is assessed by means of NARVAL (North Atlantic Regional VALidation) web-based tool. The validation of IBI against independent in situ and remote-sensing measurements is routinely conducted to evaluate model's veracity and prognostic capabilities. Noticeable efforts are in progress to define meaningful skill scores and statistical metrics to quantitatively assess the quality and reliability of the IBI model solution. Likewise, the IBI-MFC compares the IBI forecast products with other model solutions by setting up specific intercomparison exercises on overlapping areas at diverse timescales. In this context, NARVAL web tool already includes a specific module to evaluate strengths and weaknesses of IBI versus other CMEMS operational ocean forecasting systems (OOFSs). In particular, the IBI physical ocean solution is compared against the CMEMS MED and NWS OOFSs. These CMEMS regional services delivered for the Mediterranean and the North West Shelves include data assimilation schemes in their respective operational chains and generate analogous ocean forecast products to the IBI ones. A number of physical parameters (i.e. sea surface temperature, salinity and current velocities) are evaluated through NARVAL on a daily basis in the overlapping areas existing between these three regional systems. NARVAL is currently being updated in order to extend this intercomparison of ocean model parameters to the biogeochemical solutions provided by the aforementioned OOFSs. More specifically, the simulated chlorophyll concentration is evaluated over several subregions of particular concern by using as benchmark the CMEMS satellite-derived observational products. In addition to this IBI comparison against other regional CMEMS products on overlapping areas, a

The CAUSES Model Intercomparison Project: Using hindcast approach to study the U.S. summertime surface warm temperature bias

NASA Astrophysics Data System (ADS)

Ma, H. Y.; Klein, S. A.; Xie, S.; Zhang, C.; Morcrette, C. J.; Van Weverberg, K.; Petch, J.

2016-12-01

The CAUSES (Clouds Above the United States and Errors at the Surface) is a joint GASS/RGCM/ASR model intercomparison project with an observational focus (data from the U.S. DOE ARM SGP site and other observations). The goal of this project is to evaluate the role of clouds, radiation and precipitation processes in contributing to the surface air temperature bias in the region of the central U.S., which is seen in several weather and climate models. In this project, we use a short-term hindcast approach and examine the error growth due to cloud-associated processes while the large-scale state remains close to observations. The study period is from April 1 to August 31, 2011, which also covers the entire Midlatitude Continental Convective Clouds Experiment (MC3E) campaign that provides very frequent radiosondes (8 per day) and many extensive cloud and precipitation radar observations. Our preliminary analysis indicates that the warm surface air temperature bias in the mean diurnal cycle of the whole study period is very robust across all the participating models over the ARM SGP site. During the spring season (April-May), the daytime warm bias in most models is mostly due to excessive net surface shortwave flux resulting from insufficient deep convective cloud fraction or too optically thin clouds. The nighttime warm bias is likely due to the excessive downwelling longwave flux warming resulting from the persisting deep clouds. During the summer season (June-August), bias contribution from precipitation bias becomes important. The insufficient seasonal accumulated precipitation from the propagating convective systems originated from the Rockies contributes to lower soil moisture. Such condition drives the land surface to a dry state whereby radiative input can only be balanced by sensible heat loss through an increased surface air temperature. More information about the CAUSES project can be found through the following project webpage (http

Preliminary results of an intercomparison of total ozone spectrophotometers

NASA Technical Reports Server (NTRS)

Parsons, C. L.; Gerlach, J. C.; Williams, M. E.; Kerr, J. B.

1981-01-01

Preliminary results from an intercomparison of five total ozone spectrophotometers are presented. These are the Dobson spectrophotometer, the USSR M-83 ozonometer, the Canterbury filter photometer, the SenTran Company filter photometer, and the Brewer grating spectrophotometer. The pertinent characteristics of each are described, and conclusions are drawn about the agreement of each instrument's measurements with the Dobson's values over a time period of nearly one year. A discussion of the importance of calibration and long-term stability and reliability is included.

The 1997 North American Interagency Intercomparison of Ultraviolet Spectroradiometers Including Narrowband Filter Radiometers

PubMed Central

Lantz, Kathleen; Disterhoft, Patrick; Early, Edward; Thompson, Ambler; DeLuisi, John; Berndt, Jerry; Harrison, Lee; Kiedron, Peter; Ehramjian, James; Bernhard, Germar; Cabasug, Lauriana; Robertson, James; Mou, Wanfeng; Taylor, Thomas; Slusser, James; Bigelow, David; Durham, Bill; Janson, George; Hayes, Douglass; Beaubien, Mark; Beaubien, Arthur

2002-01-01

The fourth North American Intercomparison of Ultraviolet Monitoring Spectroradiometers was held September 15 to 25, 1997 at Table Mountain outside of Boulder, Colorado, USA. Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. The main purpose of the Intercomparison was to assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks. This Intercomparison was coordinated by NIST and NOAA, and included participants from the ASRC, EPA, NIST, NSF, SERC, USDA, and YES. The UV measuring instruments included scanning spectroradiometers, spectrographs, narrow band multi-filter radiometers, and broadband radiometers. Instruments were characterized for wavelength accuracy, bandwidth, stray-light rejection, and spectral irradiance responsivity. The spectral irradiance responsivity was determined two to three times outdoors to assess temporal stability. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST traceable standard lamp, and a simple convolution technique with a Gaussian slit-scattering function to account for the different bandwidths of the instruments, the measured solar irradiance from the spectroradiometers excluding the filter radiometers at 16.5 h UTC had a relative standard deviation of ±4 % for wavelengths greater than 305 nm. The relative standard deviation for the solar irradiance at 16.5 h UTC including the filter radiometer was ±4 % for filter functions above 300 nm. PMID:27446717

Introduction to the SPARC Reanalysis Intercomparison Project (S-RIP) and overview of the reanalysis systems

NASA Astrophysics Data System (ADS)

Fujiwara, Masatomo; Wright, Jonathon S.; Manney, Gloria L.; Gray, Lesley J.; Anstey, James; Birner, Thomas; Davis, Sean; Gerber, Edwin P.; Harvey, V. Lynn; Hegglin, Michaela I.; Homeyer, Cameron R.; Knox, John A.; Krüger, Kirstin; Lambert, Alyn; Long, Craig S.; Martineau, Patrick; Molod, Andrea; Monge-Sanz, Beatriz M.; Santee, Michelle L.; Tegtmeier, Susann; Chabrillat, Simon; Tan, David G. H.; Jackson, David R.; Polavarapu, Saroja; Compo, Gilbert P.; Dragani, Rossana; Ebisuzaki, Wesley; Harada, Yayoi; Kobayashi, Chiaki; McCarty, Will; Onogi, Kazutoshi; Pawson, Steven; Simmons, Adrian; Wargan, Krzysztof; Whitaker, Jeffrey S.; Zou, Cheng-Zhi

2017-01-01

The climate research community uses atmospheric reanalysis data sets to understand a wide range of processes and variability in the atmosphere, yet different reanalyses may give very different results for the same diagnostics. The Stratosphere-troposphere Processes And their Role in Climate (SPARC) Reanalysis Intercomparison Project (S-RIP) is a coordinated activity to compare reanalysis data sets using a variety of key diagnostics. The objectives of this project are to identify differences among reanalyses and understand their underlying causes, to provide guidance on appropriate usage of various reanalysis products in scientific studies, particularly those of relevance to SPARC, and to contribute to future improvements in the reanalysis products by establishing collaborative links between reanalysis centres and data users. The project focuses predominantly on differences among reanalyses, although studies that include operational analyses and studies comparing reanalyses with observations are also included when appropriate. The emphasis is on diagnostics of the upper troposphere, stratosphere, and lower mesosphere. This paper summarizes the motivation and goals of the S-RIP activity and extensively reviews key technical aspects of the reanalysis data sets that are the focus of this activity. The special issue The SPARC Reanalysis Intercomparison Project (S-RIP) in this journal serves to collect research with relevance to the S-RIP in preparation for the publication of the planned two (interim and full) S-RIP reports.

The SPARC Intercomparison of Middle Atmosphere Climatologies

NASA Technical Reports Server (NTRS)

Randel, William; Fleming, Eric; Geller, Marvin; Gelman, Mel; Hamilton, Kevin; Karoly, David; Ortland, Dave; Pawson, Steve; Swinbank, Richard; Udelhofen, Petra

2003-01-01

Our current confidence in 'observed' climatological winds and temperatures in the middle atmosphere (over altitudes approx. 10-80 km) is assessed by detailed intercomparisons of contemporary and historic data sets. These data sets include global meteorological analyses and assimilations, climatologies derived from research satellite measurements, and historical reference atmosphere circulation statistics. We also include comparisons with historical rocketsonde wind and temperature data, and with more recent lidar temperature measurements. The comparisons focus on a few basic circulation statistics, such as temperature, zonal wind, and eddy flux statistics. Special attention is focused on tropical winds and temperatures, where large differences exist among separate analyses. Assimilated data sets provide the most realistic tropical variability, but substantial differences exist among current schemes.

WCRP Task Team for the Intercomparison of Reanalyses (TIRA): Motivation and Progress

NASA Technical Reports Server (NTRS)

Bosilovich, Michael

2017-01-01

Reanalyses have proven to be an important resource for weather and climate related research, as well as societal applications at large. Several centers have emerged to produce new atmospheric reanalyses in various forms every few years. In addition, land and ocean communities are producing disciplinary uncoupled reanalyses. Current research and development in reanalysis is directed at (1) extending the length of reanalyzed period and (2) use of coupled Earth system models for climate reanalysis. While WCRPs involvement in the reanalyses communities through its Data Advisory Council (WDAC) has been substantial, for example in organizing international conferences on reanalyses, a central team of reanalyses expertise is not in place in the WCRP structure. The differences among reanalyses and their inherent uncertainties are some of the most important questions for both users and developers of reanalyses. Therefore, a collaborative effort to systematically assess and intercompare reanalyses would be a logical progression that fills the needs of the community and contributes to the WCRP mission. The primary charge to the TIRA is to develop a reanalysis intercomparison project plan that will attain the following objectives.1)To foster understanding and estimation of uncertainties in reanalysis data by intercomparison and other means 2)To communicate new developments and best practices among the reanalyses producing centers 3)To enhance the understanding of data and assimilation issues and their impact on uncertainties, leading to improved reanalyses for climate assessment 4)To communicate the strengths and weaknesses of reanalyses, their fitness for purpose, and best practices in the use of reanalysis datasets by the scientific community. This presentation outlines the need for a task team on reanalyses, their intercomparison, the objectives of the team and progress thus far.

A new PUB-working group on SLope InterComparison Experiments (SLICE)

NASA Astrophysics Data System (ADS)

McGuire, K.; Retter, M.; Freer, J.; Troch, P.; McDonnell, J.

2006-05-01

The International Association of Hydrological Sciences (IAHS) decade on Prediction in Ungauged Basins (PUB) has the scientific goal to shift hydrology from calibration reliant models to new and rich understanding- based models. To support this, six PUB science themes have been developed under the PUB Science Steering group. Theme 1 covers basin inter-comparison and classification. The SLope InterComparison Experiment (SLICE) is a newly-formed working group aligned with theme 1. Its 2- year target is to promote the improved understanding of regional hydrological characteristics via hillslope inter- comparison studies and top-down analysis of data from hillslope experiments from around the world. It will further deliver the major building blocks of a catchment classification system. A first workshop of SLICE took place 26-28 September 2005 at the HJ Andrews Experimental Forest, Oregon, USA. 40 participants from seven countries were in attendance. The program consisted of keynote presentations on the state-of-the-art of hillslope hydrology, outlining a hillslope classification system, and through small group discussion, a focus on the following questions: a.) How can we capture flow path heterogeneity at the hillslope scale with residence time distributions? b.) Can networks help characterize hillslope subsurface systems? c.) What patterns are useful to characterize in a hillslope comparison context? d.) How does bedrock permeability condition hillslope response? e.) Can we actually observe pressure waves in the field and/or how likely are they to exist at the hillslope continuum scale? The poster presents an overview of the workshop outcomes and directions of future work.

An Intercomparison of 2-D Models Within a Common Framework

NASA Technical Reports Server (NTRS)

Weisenstein, Debra K.; Ko, Malcolm K. W.; Scott, Courtney J.; Jackman, Charles H.; Fleming, Eric L.; Considine, David B.; Kinnison, Douglas E.; Connell, Peter S.; Rotman, Douglas A.; Bhartia, P. K. (Technical Monitor)

2002-01-01

A model intercomparison among the Atmospheric and Environmental Research (AER) 2-D model, the Goddard Space Flight Center (GSFC) 2-D model, and the Lawrence Livermore National Laboratory 2-D model allows us to separate differences due to model transport from those due to the model's chemical formulation. This is accomplished by constructing two hybrid models incorporating the transport parameters of the GSFC and LLNL models within the AER model framework. By comparing the results from the native models (AER and e.g. GSFC) with those from the hybrid model (e.g. AER chemistry with GSFC transport), differences due to chemistry and transport can be identified. For the analysis, we examined an inert tracer whose emission pattern is based on emission from a High Speed Civil Transport (HSCT) fleet; distributions of trace species in the 2015 atmosphere; and the response of stratospheric ozone to an HSCT fleet. Differences in NO(y) in the upper stratosphere are found between models with identical transport, implying different model representations of atmospheric chemical processes. The response of O3 concentration to HSCT aircraft emissions differs in the models from both transport-dominated differences in the HSCT-induced perturbations of H2O and NO(y) as well as from differences in the model represent at ions of O3 chemical processes. The model formulations of cold polar processes are found to be the most significant factor in creating large differences in the calculated ozone perturbations

GLM Proxy Data Generation: Methods for Stroke/Pulse Level Inter-comparison of Ground-based Lightning Reference Networks

NASA Astrophysics Data System (ADS)

Cummins, K. L.; Carey, L. D.; Schultz, C. J.; Bateman, M. G.; Cecil, D. J.; Rudlosky, S. D.; Petersen, W. A.; Blakeslee, R. J.; Goodman, S. J.

2011-12-01

In order to produce useful proxy data for the GOES-R Geostationary Lightning Mapper (GLM) in regions not covered by VLF lightning mapping systems, we intend to employ data produced by ground-based (regional or global) VLF/LF lightning detection networks. Before using these data in GLM Risk Reduction tasks, it is necessary to have a quantitative understanding of the performance of these networks, in terms of CG flash/stroke DE, cloud flash/pulse DE, location accuracy, and CLD/CG classification error. This information is being obtained through inter-comparison with LMAs and well-quantified VLF/LF lightning networks. One of our approaches is to compare "bulk" counting statistics on the spatial scale of convective cells, in order to both quantify relative performance and observe variations in cell-based temporal trends provided by each network. In addition, we are using microsecond-level stroke/pulse time correlation to facilitate detailed inter-comparisons at a more-fundamental level. The current development status of our ground-based inter-comparison and evaluation tools will be presented, and performance metrics will be discussed through a comparison of Vaisala's Global Lightning Dataset (GLD360) with the NLDN at locations within and outside the U.S.

Development of phantom and methodology for 3D and 4D dose intercomparisons for advanced lung radiotherapy

NASA Astrophysics Data System (ADS)

Caloz, Misael; Kafrouni, Marilyne; Leturgie, Quentin; Corde, Stéphanie; Downes, Simon; Lehmann, Joerg; Thwaites, David

2015-01-01

There are few reported intercomparisons or audits of combinations of advanced radiotherapy methods, particularly for 4D treatments. As part of an evaluation of the implementation of advanced radiotherapy technology, a phantom and associated methods, initially developed for in-house commissioning and QA of 4D lung treatments, has been developed further with the aim of using it for end-to-end dose intercomparison of 4D treatment planning and delivery. The respiratory thorax phantom can house moving inserts with variable speed (breathing rate) and motion amplitude. In one set-up mode it contains a small ion chamber for point dose measurements, or alternatively it can hold strips of radiochromic film to measure dose distributions. Initial pilot and feasibility measurements have been carried out in one hospital to thoroughly test the methods and procedures before using it more widely across a range of hospitals and treatment systems. Overall, the results show good agreement between measured and calculated doses and distributions, supporting the use of the phantom and methodology for multi-centre intercomparisons. However, before wider use, refinements of the method and analysis are currently underway particularly for the film measurements.

Intercomparison of formaldehyde measurements in the tropical atmosphere

NASA Astrophysics Data System (ADS)

Trapp, Dorothea; De Serves, Claes

An intercomparison of formaldehyde measurements at low concentrations ( < 2.0 ppbv) was performed during the ASTROS '93 field campaign in Venezuela (Atmospheric Studies in the TROpical Savannah, September 1993). Formaldehyde was collected and measured by two different techniques: a porous membrane diffusion scrubber with fluorescent detection of the Hantzsch reaction product, and DNPH-traps (2,4-dinitrophenylhydrazine) followed by high performance liquid chromatography with a UV/VIS absorption detector. The time resolution for the diffusion scrubber instrument was 5 min while the DNPH-tr;ap samples were integrated over 30-60 min. The measured concentrations range from the detection limits (0.045 ppbv for the diffusion scrubber, 0.1 ppbv for the DNPH-traps) up to 2 ppbv. The correlation coefficient between the two techniques is r2 = 0.80 (n = 48) and the slope equals unity (1.02 ± 0.03). Both methods are found to be suitable for field experiments in the low ppbv range of formaldehyde.

Sources of Differences in On-Orbit Total Solar Irradiance Measurements and Description of Proposed Laboratory Intercomparison

NASA Technical Reports Server (NTRS)

Butler, J.J.; Johnson, B. C.; Rice, J. P.; Shirley, E. L.; Barnes, R.A.

2008-01-01

There is a 5 W/sq m (about 0.35 %) difference between current on-orbit Total Solar Irradiance (TSI) measurements. On 18-20 July 2005, a workshop was held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland that focused on understanding possible reasons for this difference, through an examination of the instrument designs, calibration approaches, and appropriate measurement equations. The instruments studied in that workshop included the Active Cavity Radiometer Irradiance Monitor III (ACRIM III) on the Active Cavity Radiometer Irradiance Monitor SATellite (ACRIMSAT), the Total Irradiance Monitor (TIM) on the Solar Radiation and Climate Experiment (SORCE), the Variability of solar IRradiance and Gravity Oscillations (VIRGO) on the Solar and Heliospheric Observatory (SOHO), and the Earth Radiation Budget Experiment (ERBE) on the Earth Radiation Budget Satellite (ERBS). Presentations for each instrument included descriptions of its design, its measurement equation and uncertainty budget, and the methods used to assess on-orbit degradation. The workshop also included a session on satellite- and ground-based instrument comparisons and a session on laboratory-based comparisons and the application of new laboratory comparison techniques. The workshop has led to investigations of the effects of diffraction and of aperture area measurements on the differences between instruments. In addition, a laboratory-based instrument comparison is proposed that uses optical power measurements (with lasers that underEll the apertures of the TSI instruments), irradiance measurements (with lasers that overfill the apertures of the TSI instrument), and a cryogenic electrical substitution radiometer as a standard for comparing the instruments. A summary of the workshop and an overview of the proposed research efforts are presented here.

Intercomparisons of radiosondes and an airborne refractometer for measuring radio ducts

NASA Astrophysics Data System (ADS)

Morrissey, J. F.; Izumi, Y.; Cote, O. R.

1986-07-01

The capabilities of two types of radiosondes and an aircraft refractometer to measure radio ducting conditions were compared in a series of flights in September 1985 at Chatham, Mass., on Cape Cod. The tests were part of a program studying radio propagation on Air Force communication links. The intercomparisons were made between data from a refractometer mounted on a small single engine aircraft (Cessna 172) and data from an operational National Weather Service synoptic sounding system. The synoptic sonde and the portable sonde were often on the same balloon train. The comparisons show that the aircraft refractometer data indicate the highest number of ducts and the synoptic data the least number of ducts.

Intercomparison of active and passive instruments for radon and radon progeny in North America

DOE Office of Scientific and Technical Information (OSTI.GOV)

George, A.C.; Tu, Keng-Wu; Knutson, E.O.

1995-02-01

An intercomparison exercise for radon and radon progeny instruments and methods was held at the Environmental Measurements Laboratory (EML) from April 22--May 2, 1994. The exercise was conducted in the new EML radon test and calibration facility in which conditions of exposure are very well controlled. The detection systems of the intercompared instruments consisted of. (1) pulse ionization chambers, (2) electret ionization chambers, (3) scintillation detectors, (4) alpha particle spectrometers with silicon diodes, surface barrier or diffused junction detectors, (5) registration of nuclear tracks in solid-state materials, and (6) activated carbon collectors counted by gamma-ray spectrometry or by alpha- andmore » beta-liquid scintillation counting. 23 private firms, government laboratories and universities participated with a 165 passive integrating devices consisting of: Activated carbon collectors, nuclear alpha track detectors and electret ionization chambers, and 11 active and passive continuous radon monitors. Five portable integrating and continuous instruments were intercompared for radon progeny. Forty grab samples for radon progeny were taken by five groups that participated in person to test and evaluate their primary instruments and methods that measure individual radon progeny and the potential alpha energy concentration (PAEC) in indoor air. Results indicate that more than 80% of the measurements for radon performed with a variety of instruments, are within {plus_minus}10% of actual value. The majority of the instruments that measure individual radon progeny and the PAEC gave results that are in good agreement with the EML reference value. Radon progeny measurements made with continuous and integrating instruments are satisfactory with room for improvement.« less

The 1995 North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers

PubMed Central

Early, Edward; Thompson, Ambler; Johnson, Carol; DeLuisi, John; Disterhoft, Patrick; Wardle, David; Wu, Edmund; Mou, Wanfeng; Sun, Yongchen; Lucas, Timothy; Mestechkina, Tanya; Harrison, Lee; Berndt, Jerry; Hayes, Douglas S.

1998-01-01

Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. To assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks, the second North American Intercomparison of Ultraviolet Monitoring Spectroradiometers was held June 12 to 23, 1995 at Table Mountain outside Boulder, Colorado, USA. This Intercomparison was coordinated by the National Institute of Standards and Technology (NIST) and the National Oceanic and Atmospheric Administration (NOAA). Participating agencies were the Environmental Protection Agency; the National Science Foundation; the Smithsonian Environmental Research Center; the Department of Agriculture; and the Atmospheric Environment Service, Canada. Instruments were characterized for wavelength uncertainty, bandwidth, stray-light rejection, and spectral irradiance responsivity, the latter with a NIST standard lamp operating in a specially designed field calibration unit. The spectral irradiance responsivity, determined once indoors and twice outdoors, demonstrated that while the responsivities changed upon moving the instruments, they were relatively stable when the instruments remained outdoors. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST standard lamp and three different convolution functions to account for the different bandwidths of the instruments, the measured solar irradiances generally agreed to within 3 %. PMID:28009371

The 1994 North American Interagency Intercomparison of Ultraviolet Monitoring Spectroradiometers

PubMed Central

Thompson, Ambler; Early, Edward A.; DeLuisi, John; Disterhoft, Patrick; Wardle, David; Kerr, James; Rives, John; Sun, Yongchen; Lucas, Timothy; Mestechkina, Tanya; Neale, Patrick

1997-01-01

Concern over stratospheric ozone depletion has prompted several government agencies in North America to establish networks of spectroradiometers for monitoring solar ultraviolet irradiance at the surface of the Earth. To assess the ability of spectroradiometers to accurately measure solar ultraviolet irradiance, and to compare the results between instruments of different monitoring networks, the first North American Intercomparison of Ultraviolet Monitoring Spectroradiometers was held September 19–29, 1994 at Table Mountain outside Boulder, Colorado, USA. This Intercomparison was coordinated by the National Institute of Standards and Technology and the National Oceanic and Atmospheric Administration (NOAA). Participating agencies were the Environmental Protection Agency, National Science Foundation, Smithsonian Environmental Research Center, and Atmospheric Environment Service, Canada. Instruments were characterized for wavelength accuracy, bandwidth, stray-light rejection, and spectral irradiance responsivity, the latter with a NIST standard lamp calibrated to operate in the horizontal position. The spectral irradiance responsivity was determined once indoors and twice outdoors, and demonstrated that, while the responsivities changed upon moving the instruments, they were relatively stable when the instruments remained outdoors. Synchronized spectral scans of the solar irradiance were performed over several days. Using the spectral irradiance responsivities determined with the NIST standard lamp, and a simple convolution technique to account for the different bandwidths of the instruments, the measured solar irradiances agreed within 5 %. PMID:27805148

GMMIP (v1.0) contribution to CMIP6: Global Monsoons Model Inter-comparison Project

NASA Astrophysics Data System (ADS)

Zhou, Tianjun; Turner, Andrew G.; Kinter, James L.; Wang, Bin; Qian, Yun; Chen, Xiaolong; Wu, Bo; Wang, Bin; Liu, Bo; Zou, Liwei; He, Bian

2016-10-01

The Global Monsoons Model Inter-comparison Project (GMMIP) has been endorsed by the panel of Coupled Model Inter-comparison Project (CMIP) as one of the participating model inter-comparison projects (MIPs) in the sixth phase of CMIP (CMIP6). The focus of GMMIP is on monsoon climatology, variability, prediction and projection, which is relevant to four of the "Grand Challenges" proposed by the World Climate Research Programme. At present, 21 international modeling groups are committed to joining GMMIP. This overview paper introduces the motivation behind GMMIP and the scientific questions it intends to answer. Three tiers of experiments, of decreasing priority, are designed to examine (a) model skill in simulating the climatology and interannual-to-multidecadal variability of global monsoons forced by the sea surface temperature during historical climate period; (b) the roles of the Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation in driving variations of the global and regional monsoons; and (c) the effects of large orographic terrain on the establishment of the monsoons. The outputs of the CMIP6 Diagnostic, Evaluation and Characterization of Klima experiments (DECK), "historical" simulation and endorsed MIPs will also be used in the diagnostic analysis of GMMIP to give a comprehensive understanding of the roles played by different external forcings, potential improvements in the simulation of monsoon rainfall at high resolution and reproducibility at decadal timescales. The implementation of GMMIP will improve our understanding of the fundamental physics of changes in the global and regional monsoons over the past 140 years and ultimately benefit monsoons prediction and projection in the current century.

The Agricultural Model Intercomparison and Improvement Project (AgMIP): Progress and Preliminary Results

NASA Astrophysics Data System (ADS)

Rosenzweig, C.

2011-12-01

The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a distributed climate-scenario simulation exercise for historical model intercomparison and future climate change conditions with participation of multiple crop and agricultural trade modeling groups around the world. The goals of AgMIP are to improve substantially the characterization of risk of hunger and world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Recent progress and the current status of AgMIP will be presented, highlighting three areas of activity: preliminary results from crop pilot studies, outcomes from regional workshops, and emerging scientific challenges. AgMIP crop modeling efforts are being led by pilot studies, which have been established for wheat, maize, rice, and sugarcane. These crop-specific initiatives have proven instrumental in testing and contributing to AgMIP protocols, as well as creating preliminary results for aggregation and input to agricultural trade models. Regional workshops are being held to encourage collaborations and set research activities in motion for key agricultural areas. The first of these workshops was hosted by Embrapa and UNICAMP and held in Campinas, Brazil. Outcomes from this meeting have informed crop modeling research activities within South America, AgMIP protocols, and future regional workshops. Several scientific challenges have emerged and are currently being addressed by AgMIP researchers. Areas of particular interest include geospatial weather generation, ensemble methods for climate scenarios and crop models, spatial aggregation of field-scale yields to regional and global production, and characterization of future changes in climate variability.

New Laboratory Methods for Characterizing the Immersion Factors for Irradiance

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Zibordi, Giuseppe; DAlimonte, Davide; vaderLinde, Dirk; Brown, James W.

2003-01-01

The experimental determination of the immersion factor, I(sub f)(lambda), of irradiance collectors is a requirement of any in-water radiometer. The eighth SeaWiFS Intercalibration Round-Robin Experiment (SIRREX-8) showed different implementations, at different laboratories, of the same I(sub f)(lambda) measurement protocol. The different implementations make use of different setups, volumes, and water types. Consequently, they exhibit different accuracies and require different execution times for characterizing an irradiance sensor. In view of standardizing the characterization of I(sub f)(lambda) values for in-water radiometers, together with an increase in the accuracy of methods and a decrease in the execution time, alternative methods are presented, and assessed versus the traditional method. The proposed new laboratory methods include: a) the continuous method, in which optical measurements taken with discrete water depths are substituted by continuous profiles created by removing the water from the water vessel at a constant flow rate (which significantly reduces the time required for the characterization of a single radiometer); and b) the Compact Portable Advanced Characterization Tank (ComPACT) method, in which the commonly used large tanks are replaced by a small water vessel, thereby allowing the determination of I(sub f)(lambda) values with a small water volume, and more importantly, permitting I(sub f)(lambda) characterizations with pure water. Intercomparisons between the continuous and the traditional method showed results within the variance of I(sub f) (lambda) determinations. The use of the continuous method, however, showed a much shorter realization time. Intercomparisons between the ComPACT and the traditional method showed generally higher I(sub f)(lambda) values for the former. This is in agreement with the generalized expectations of a reduction in scattering effects, because of the use of pure water with the ComPACT method versus the use of

Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics

NASA Astrophysics Data System (ADS)

Bemmerer, D.; Cowan, T. E.; Gohl, S.; Ilgner, C.; Junghans, A. R.; Reinhardt, T. P.; Rimarzig, B.; Reinicke, S.; Röder, M.; Schmidt, K.; Schwengner, R.; Stöckel, K.; Szücs, T.; Takács, M.; Wagner, A.; Wagner, L.; Zuber, K.

2015-05-01

Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, proteced from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, in the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise has been carried out using the same HPGe detector in a typical nuclear astrophysics setup at several sites, including the Dresden Felsenkeller underground laboratory. It was found that its rock overburden of 45m rock, together with an active veto against the remaining muon flux, reduces the background to a level that is similar to the deep underground scenario. Based on this finding, a used 5 MV pelletron tandem with 250 μA upcharge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is underway. The project is now fully funded. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and the planned access possibilities for external users will be reported.

GLM Proxy Data Generation: Methods for Stroke/Pulse Level Inter-Comparison of Ground-Based Lightning Reference Networks

NASA Technical Reports Server (NTRS)

Cummins, Kenneth L.; Carey, Lawrence D.; Schultz, Christopher J.; Bateman, Monte G.; Cecil, Daniel J.; Rudlosky, Scott D.; Petersen, Walter Arthur; Blakeslee, Richard J.; Goodman, Steven J.

2011-01-01

In order to produce useful proxy data for the GOES-R Geostationary Lightning Mapper (GLM) in regions not covered by VLF lightning mapping systems, we intend to employ data produced by ground-based (regional or global) VLF/LF lightning detection networks. Before using these data in GLM Risk Reduction tasks, it is necessary to have a quantitative understanding of the performance of these networks, in terms of CG flash/stroke DE, cloud flash/pulse DE, location accuracy, and CLD/CG classification error. This information is being obtained through inter-comparison with LMAs and well-quantified VLF/LF lightning networks. One of our approaches is to compare "bulk" counting statistics on the spatial scale of convective cells, in order to both quantify relative performance and observe variations in cell-based temporal trends provided by each network. In addition, we are using microsecond-level stroke/pulse time correlation to facilitate detailed inter-comparisons at a more-fundamental level. The current development status of our ground-based inter-comparison and evaluation tools will be presented, and performance metrics will be discussed through a comparison of Vaisala s Global Lightning Dataset (GLD360) with the NLDN at locations within and outside the U.S.

Improvement of analytical capabilities of neutron activation analysis laboratory at the Colombian Geological Survey

NASA Astrophysics Data System (ADS)

Parrado, G.; Cañón, Y.; Peña, M.; Sierra, O.; Porras, A.; Alonso, D.; Herrera, D. C.; Orozco, J.

2016-07-01

The Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey has developed a technique for multi-elemental analysis of soil and plant matrices, based on Instrumental Neutron Activation Analysis (INAA) using the comparator method. In order to evaluate the analytical capabilities of the technique, the laboratory has been participating in inter-comparison tests organized by Wepal (Wageningen Evaluating Programs for Analytical Laboratories). In this work, the experimental procedure and results for the multi-elemental analysis of four soil and four plant samples during participation in the first round on 2015 of Wepal proficiency test are presented. Only elements with radioactive isotopes with medium and long half-lives have been evaluated, 15 elements for soils (As, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Th, U and Zn) and 7 elements for plants (Br, Co, Cr, Fe, K, Na and Zn). The performance assessment by Wepal based on Z-score distributions showed that most results obtained |Z-scores| ≤ 3.

IPRT polarized radiative transfer model intercomparison project - Three-dimensional test cases (phase B)

NASA Astrophysics Data System (ADS)

Emde, Claudia; Barlakas, Vasileios; Cornet, Céline; Evans, Frank; Wang, Zhen; Labonotte, Laurent C.; Macke, Andreas; Mayer, Bernhard; Wendisch, Manfred

2018-04-01

Initially unpolarized solar radiation becomes polarized by scattering in the Earth's atmosphere. In particular molecular scattering (Rayleigh scattering) polarizes electromagnetic radiation, but also scattering of radiation at aerosols, cloud droplets (Mie scattering) and ice crystals polarizes. Each atmospheric constituent produces a characteristic polarization signal, thus spectro-polarimetric measurements are frequently employed for remote sensing of aerosol and cloud properties. Retrieval algorithms require efficient radiative transfer models. Usually, these apply the plane-parallel approximation (PPA), assuming that the atmosphere consists of horizontally homogeneous layers. This allows to solve the vector radiative transfer equation (VRTE) efficiently. For remote sensing applications, the radiance is considered constant over the instantaneous field-of-view of the instrument and each sensor element is treated independently in plane-parallel approximation, neglecting horizontal radiation transport between adjacent pixels (Independent Pixel Approximation, IPA). In order to estimate the errors due to the IPA approximation, three-dimensional (3D) vector radiative transfer models are required. So far, only a few such models exist. Therefore, the International Polarized Radiative Transfer (IPRT) working group of the International Radiation Commission (IRC) has initiated a model intercomparison project in order to provide benchmark results for polarized radiative transfer. The group has already performed an intercomparison for one-dimensional (1D) multi-layer test cases [phase A, 1]. This paper presents the continuation of the intercomparison project (phase B) for 2D and 3D test cases: a step cloud, a cubic cloud, and a more realistic scenario including a 3D cloud field generated by a Large Eddy Simulation (LES) model and typical background aerosols. The commonly established benchmark results for 3D polarized radiative transfer are available at the IPRT website (http

ACTRIS ACSM intercomparison - Part 2: Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

NASA Astrophysics Data System (ADS)

Fröhlich, R.; Crenn, V.; Setyan, A.; Belis, C. A.; Canonaco, F.; Favez, O.; Riffault, V.; Slowik, J. G.; Aas, W.; Aijälä, M.; Alastuey, A.; Artiñano, B.; Bonnaire, N.; Bozzetti, C.; Bressi, M.; Carbone, C.; Coz, E.; Croteau, P. L.; Cubison, M. J.; Esser-Gietl, J. K.; Green, D. C.; Gros, V.; Heikkinen, L.; Herrmann, H.; Jayne, J. T.; Lunder, C. R.; Minguillón, M. C.; Močnik, G.; O'Dowd, C. D.; Ovadnevaite, J.; Petralia, E.; Poulain, L.; Priestman, M.; Ripoll, A.; Sarda-Estève, R.; Wiedensohler, A.; Baltensperger, U.; Sciare, J.; Prévôt, A. S. H.

2015-02-01

Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSM) performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM) from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM), and one high-resolution ToF aerosol mass spectrometer (AMS) were operated in parallel for about three weeks in November and December 2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF) utilising the multilinear engine 2 (ME-2). Except for the organic contribution of m/z 44 to the total organics (f44), which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f44 in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbon-like organic aerosol (HOA), cooking-related organic aerosol (COA), biomass burning-related organic aerosol (BBOA) and secondary oxygenated organic aerosol (OOA). Individual application and optimisation of the ME-2 boundary conditions (profile constraints) are discussed together with the investigation of the influence of alternative anchors (reference profiles). A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative SD from the mean between 13.7 and 22.7% of the source's average mass contribution depending on the factors (HOA: 14.3 ± 2.2%, COA: 15.0 ± 3.4%, OOA: 41.5 ± 5.7%, BBOA: 29.3 ± 5.0%). Factors which tend to be subject to minor factor mixing (in this case COA

GEO-LEO reflectance band inter-comparison with BRDF and atmospheric scattering corrections

NASA Astrophysics Data System (ADS)

Chang, Tiejun; Xiong, Xiaoxiong Jack; Keller, Graziela; Wu, Xiangqian

2017-09-01

The inter-comparison of the reflective solar bands between the instruments onboard a geostationary orbit satellite and onboard a low Earth orbit satellite is very helpful to assess their calibration consistency. GOES-R was launched on November 19, 2016 and Himawari 8 was launched October 7, 2014. Unlike the previous GOES instruments, the Advanced Baseline Imager on GOES-16 (GOES-R became GOES-16 after November 29 when it reached orbit) and the Advanced Himawari Imager (AHI) on Himawari 8 have onboard calibrators for the reflective solar bands. The assessment of calibration is important for their product quality enhancement. MODIS and VIIRS, with their stringent calibration requirements and excellent on-orbit calibration performance, provide good references. The simultaneous nadir overpass (SNO) and ray-matching are widely used inter-comparison methods for reflective solar bands. In this work, the inter-comparisons are performed over a pseudo-invariant target. The use of stable and uniform calibration sites provides comparison with appropriate reflectance level, accurate adjustment for band spectral coverage difference, reduction of impact from pixel mismatching, and consistency of BRDF and atmospheric correction. The site in this work is a desert site in Australia (latitude -29.0 South; longitude 139.8 East). Due to the difference in solar and view angles, two corrections are applied to have comparable measurements. The first is the atmospheric scattering correction. The satellite sensor measurements are top of atmosphere reflectance. The scattering, especially Rayleigh scattering, should be removed allowing the ground reflectance to be derived. Secondly, the angle differences magnify the BRDF effect. The ground reflectance should be corrected to have comparable measurements. The atmospheric correction is performed using a vector version of the Second Simulation of a Satellite Signal in the Solar Spectrum modeling and BRDF correction is performed using a semi

GMMIP (v1.0) contribution to CMIP6: Global Monsoons Model Inter-comparison Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Tianjun; Turner, Andrew G.; Kinter, James L.

The Global Monsoons Model Inter-comparison Project (GMMIP) has been endorsed by the panel of Coupled Model Inter-comparison Project (CMIP) as one of the participating model inter-comparison projects (MIPs) in the sixth phase of CMIP (CMIP6). The focus of GMMIP is on monsoon climatology, variability, prediction and projection, which is relevant to four of the “Grand Challenges” proposed by the World Climate Research Programme. At present, 21 international modeling groups are committed to joining GMMIP. This overview paper introduces the motivation behind GMMIP and the scientific questions it intends to answer. Three tiers of experiments, of decreasing priority, are designed to examinemore » (a) model skill in simulating the climatology and interannual-to-multidecadal variability of global monsoons forced by the sea surface temperature during historical climate period; (b) the roles of the Interdecadal Pacific Oscillation and Atlantic Multidecadal Oscillation in driving variations of the global and regional monsoons; and (c) the effects of large orographic terrain on the establishment of the monsoons. The outputs of the CMIP6 Diagnostic, Evaluation and Characterization of Klima experiments (DECK), “historical” simulation and endorsed MIPs will also be used in the diagnostic analysis of GMMIP to give a comprehensive understanding of the roles played by different external forcings, potential improvements in the simulation of monsoon rainfall at high resolution and reproducibility at decadal timescales. The implementation of GMMIP will improve our understanding of the fundamental physics of changes in the global and regional monsoons over the past 140 years and ultimately benefit monsoons prediction and projection in the current century.« less

Intercomparison Project on Parameterizations of Large-Scale Dynamics for Simulations of Tropical Convection

NASA Astrophysics Data System (ADS)

Sobel, A. H.; Wang, S.; Bellon, G.; Sessions, S. L.; Woolnough, S.

2013-12-01

Parameterizations of large-scale dynamics have been developed in the past decade for studying the interaction between tropical convection and large-scale dynamics, based on our physical understanding of the tropical atmosphere. A principal advantage of these methods is that they offer a pathway to attack the key question of what controls large-scale variations of tropical deep convection. These methods have been used with both single column models (SCMs) and cloud-resolving models (CRMs) to study the interaction of deep convection with several kinds of environmental forcings. While much has been learned from these efforts, different groups' efforts are somewhat hard to compare. Different models, different versions of the large-scale parameterization methods, and experimental designs that differ in other ways are used. It is not obvious which choices are consequential to the scientific conclusions drawn and which are not. The methods have matured to the point that there is value in an intercomparison project. In this context, the Global Atmospheric Systems Study - Weak Temperature Gradient (GASS-WTG) project was proposed at the Pan-GASS meeting in September 2012. The weak temperature gradient approximation is one method to parameterize large-scale dynamics, and is used in the project name for historical reasons and simplicity, but another method, the damped gravity wave (DGW) method, will also be used in the project. The goal of the GASS-WTG project is to develop community understanding of the parameterization methods currently in use. Their strengths, weaknesses, and functionality in models with different physics and numerics will be explored in detail, and their utility to improve our understanding of tropical weather and climate phenomena will be further evaluated. This presentation will introduce the intercomparison project, including background, goals, and overview of the proposed experimental design. Interested groups will be invited to join (it will not be

Inter-comparison of dynamic models for radionuclide transfer to marine biota in a Fukushima accident scenario

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vives i Batlle, J.; Beresford, N. A.; Beaugelin-Seiller, K.

We report an inter-comparison of eight models designed to predict the radiological exposure of radionuclides in marine biota. The models were required to simulate dynamically the uptake and turnover of radionuclides by marine organisms. Model predictions of radionuclide uptake and turnover using kinetic calculations based on biological half-life (TB1/2) and/or more complex metabolic modelling approaches were used to predict activity concentrations and, consequently, dose rates of 90Sr, 131I and 137Cs to fish, crustaceans, macroalgae and molluscs under circumstances where the water concentrations are changing with time. For comparison, the ERICA Tool, a model commonly used in environmental assessment, and whichmore » uses equilibrium concentration ratios, was also used. As input to the models we used hydrodynamic forecasts of water and sediment activity concentrations using a simulated scenario reflecting the Fukushima accident releases. Although model variability is important, the intercomparison gives logical results, in that the dynamic models predict consistently a pattern of delayed rise of activity concentration in biota and slow decline instead of the instantaneous equilibrium with the activity concentration in seawater predicted by the ERICA Tool. The differences between ERICA and the dynamic models increase the shorter the TB1/2 becomes; however, there is significant variability between models, underpinned by parameter and methodological differences between them. The need to validate the dynamic models used in this intercomparison has been highlighted, particularly in regards to optimisation of the model biokinetic parameters.« less

NDSC Lidar Intercomparisons and Validation: OPAL and MLO3 Campaigns in 1995

NASA Technical Reports Server (NTRS)

McDermid, Stuart; McGee, Thomas J.; Stuart, Daan P. J.

1996-01-01

The Network for the Detection of Stratospheric Change (NDSC) has developed and adopted a Validation Policy in order to ensure that the results submitted and stored in its archives are of a known, high quality. As a part of this validation policy, blind instrument intercomparisons are considered an essential element in the certification of NDSC instruments and a specific format for these campaigns has been recommended by the NDSC-Steering Committee.

Intercomparison of SO2 camera systems for imaging volcanic gas plumes

NASA Astrophysics Data System (ADS)

Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-François; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

2015-07-01

SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

The global gridded crop model intercomparison: Data and modeling protocols for Phase 1 (v1.0)

DOE PAGES

Elliott, J.; Müller, C.; Deryng, D.; ...

2015-02-11

We present protocols and input data for Phase 1 of the Global Gridded Crop Model Intercomparison, a project of the Agricultural Model Intercomparison and Improvement Project (AgMIP). The project consist of global simulations of yields, phenologies, and many land-surface fluxes using 12–15 modeling groups for many crops, climate forcing data sets, and scenarios over the historical period from 1948 to 2012. The primary outcomes of the project include (1) a detailed comparison of the major differences and similarities among global models commonly used for large-scale climate impact assessment, (2) an evaluation of model and ensemble hindcasting skill, (3) quantification ofmore » key uncertainties from climate input data, model choice, and other sources, and (4) a multi-model analysis of the agricultural impacts of large-scale climate extremes from the historical record.« less

Sources of Differences in On-Orbital Total Solar Irradiance Measurements and Description of a Proposed Laboratory Intercomparison

PubMed Central

Butler, J. J; Johnson, B. C; Rice, J. P; Shirley, E. L; Barnes, R. A

2008-01-01

There is a 5 W/m2 (about 0.35 %) difference between current on-orbit Total Solar Irradiance (TSI) measurements. On 18–20 July 2005, a workshop was held at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland that focused on understanding possible reasons for this difference, through an examination of the instrument designs, calibration approaches, and appropriate measurement equations. The instruments studied in that workshop included the Active Cavity Radiometer Irradiance Monitor III (ACRIM III) on the Active Cavity Radiometer Irradiance Monitor SATellite (ACRIMSAT), the Total Irradiance Monitor (TIM) on the Solar Radiation and Climate Experiment (SORCE), the Variability of solar IRradiance and Gravity Oscillations (VIRGO) on the Solar and Heliospheric Observatory (SOHO), and the Earth Radiation Budget Experiment (ERBE) on the Earth Radiation Budget Satellite (ERBS). Presentations for each instrument included descriptions of its design, its measurement equation and uncertainty budget, and the methods used to assess on-orbit degradation. The workshop also included a session on satellite- and ground-based instrument comparisons and a session on laboratory-based comparisons and the application of new laboratory comparison techniques. The workshop has led to investigations of the effects of diffraction and of aperture area measurements on the differences between instruments. In addition, a laboratory-based instrument comparison is proposed that uses optical power measurements (with lasers that underfill the apertures of the TSI instruments), irradiance measurements (with lasers that overfill the apertures of the TSI instrument), and a cryogenic electrical substitution radiometer as a standard for comparing the instruments. A summary of the workshop and an overview of the proposed research efforts are presented here. PMID:27096120

Looking beyond general metrics for model comparison - lessons from an international model intercomparison study

NASA Astrophysics Data System (ADS)

de Boer-Euser, Tanja; Bouaziz, Laurène; De Niel, Jan; Brauer, Claudia; Dewals, Benjamin; Drogue, Gilles; Fenicia, Fabrizio; Grelier, Benjamin; Nossent, Jiri; Pereira, Fernando; Savenije, Hubert; Thirel, Guillaume; Willems, Patrick

2017-01-01

International collaboration between research institutes and universities is a promising way to reach consensus on hydrological model development. Although model comparison studies are very valuable for international cooperation, they do often not lead to very clear new insights regarding the relevance of the modelled processes. We hypothesise that this is partly caused by model complexity and the comparison methods used, which focus too much on a good overall performance instead of focusing on a variety of specific events. In this study, we use an approach that focuses on the evaluation of specific events and characteristics. Eight international research groups calibrated their hourly model on the Ourthe catchment in Belgium and carried out a validation in time for the Ourthe catchment and a validation in space for nested and neighbouring catchments. The same protocol was followed for each model and an ensemble of best-performing parameter sets was selected. Although the models showed similar performances based on general metrics (i.e. the Nash-Sutcliffe efficiency), clear differences could be observed for specific events. We analysed the hydrographs of these specific events and conducted three types of statistical analyses on the entire time series: cumulative discharges, empirical extreme value distribution of the peak flows and flow duration curves for low flows. The results illustrate the relevance of including a very quick flow reservoir preceding the root zone storage to model peaks during low flows and including a slow reservoir in parallel with the fast reservoir to model the recession for the studied catchments. This intercomparison enhanced the understanding of the hydrological functioning of the catchment, in particular for low flows, and enabled to identify present knowledge gaps for other parts of the hydrograph. Above all, it helped to evaluate each model against a set of alternative models.

Design of the MISMIP+, ISOMIP+, and MISOMIP ice-sheet, ocean, and coupled ice sheet-ocean intercomparison projects

NASA Astrophysics Data System (ADS)

Asay-Davis, Xylar; Cornford, Stephen; Martin, Daniel; Gudmundsson, Hilmar; Holland, David; Holland, Denise

2015-04-01

The MISMIP and MISMIP3D marine ice sheet model intercomparison exercises have become popular benchmarks, and several modeling groups have used them to show how their models compare to both analytical results and other models. Similarly, the ISOMIP (Ice Shelf-Ocean Model Intercomparison Project) experiments have acted as a proving ground for ocean models with sub-ice-shelf cavities.As coupled ice sheet-ocean models become available, an updated set of benchmark experiments is needed. To this end, we propose sequel experiments, MISMIP+ and ISOMIP+, with an end goal of coupling the two in a third intercomparison exercise, MISOMIP (the Marine Ice Sheet-Ocean Model Intercomparison Project). Like MISMIP3D, the MISMIP+ experiments take place in an idealized, three-dimensional setting and compare full 3D (Stokes) and reduced, hydrostatic models. Unlike the earlier exercises, the primary focus will be the response of models to sub-shelf melting. The chosen configuration features an ice shelf that experiences substantial lateral shear and buttresses the upstream ice, and so is well suited to melting experiments. Differences between the steady states of each model are minor compared to the response to melt-rate perturbations, reflecting typical real-world applications where parameters are chosen so that the initial states of all models tend to match observations. The three ISOMIP+ experiments have been designed to to make use of the same bedrock topography as MISMIP+ and using ice-shelf geometries from MISMIP+ results produced by the BISICLES ice-sheet model. The first two experiments use static ice-shelf geometries to simulate the evolution of ocean dynamics and resulting melt rates to a quasi-steady state when far-field forcing changes in either from cold to warm or from warm to cold states. The third experiment prescribes 200 years of dynamic ice-shelf geometry (with both retreating and advancing ice) based on a BISICLES simulation along with similar flips between warm and

SOIL moisture data intercomparison

NASA Astrophysics Data System (ADS)

Kerr, Yann; Rodriguez-Frenandez, Nemesio; Al-Yaari, Amen; Parens, Marie; Molero, Beatriz; Mahmoodi, Ali; Mialon, Arnaud; Richaume, Philippe; Bindlish, Rajat; Mecklenburg, Susanne; Wigneron, Jean-Pierre

2016-04-01

The Soil Moisture and Ocean Salinity satellite (SMOS) was launched in November 2009 and started delivering data in January 2010. Subsequently, the satellite has been in operation for over 6 years while the retrieval algorithms from Level 1 to Level 2 underwent significant evolutions as knowledge improved. Other approaches for retrieval at Level 2 over land were also investigated while Level 3 and 4 were initiated. In this présentation these improvements are assessed by inter-comparisons of the current Level 2 (V620) against the previous version (V551) and new products either using neural networks or Level 3. In addition a global evaluation of different SMOS soil moisture (SM) products is performed comparing products with those of model simulations and other satellites (AMSR E/ AMSR2 and ASCAT). Finally, all products were evaluated against in situ measurements of soil moisture (SM). The study demonstrated that the V620 shows a significant improvement (including those at level1 improving level2)) with respect to the earlier version V551. Results also show that neural network based approaches can yield excellent results over areas where other products are poor. Finally, global comparison indicates that SMOS behaves very well when compared to other sensors/approaches and gives consistent results over all surfaces from very dry (African Sahel, Arizona), to wet (tropical rain forests). RFI (Radio Frequency Interference) is still an issue even though detection has been greatly improved while RFI sources in several areas of the world are significantly reduced. When compared to other satellite products, the analysis shows that SMOS achieves its expected goals and is globally consistent over different eco climate regions from low to high latitudes and throughout the seasons.

Clinical Laboratory Automation: A Case Study

PubMed Central

Archetti, Claudia; Montanelli, Alessandro; Finazzi, Dario; Caimi, Luigi; Garrafa, Emirena

2017-01-01

Background This paper presents a case study of an automated clinical laboratory in a large urban academic teaching hospital in the North of Italy, the Spedali Civili in Brescia, where four laboratories were merged in a unique laboratory through the introduction of laboratory automation. Materials and Methods The analysis compares the preautomation situation and the new setting from a cost perspective, by considering direct and indirect costs. It also presents an analysis of the turnaround time (TAT). The study considers equipment, staff and indirect costs. Results The introduction of automation led to a slight increase in equipment costs which is highly compensated by a remarkable decrease in staff costs. Consequently, total costs decreased by 12.55%. The analysis of the TAT shows an improvement of nonemergency exams while emergency exams are still validated within the maximum time imposed by the hospital. Conclusions The strategy adopted by the management, which was based on re-using the available equipment and staff when merging the pre-existing laboratories, has reached its goal: introducing automation while minimizing the costs. Significance for public health Automation is an emerging trend in modern clinical laboratories with a positive impact on service level to patients and on staff safety as shown by different studies. In fact, it allows process standardization which, in turn, decreases the frequency of outliers and errors. In addition, it induces faster processing times, thus improving the service level. On the other side, automation decreases the staff exposition to accidents strongly improving staff safety. In this study, we analyse a further potential benefit of automation, that is economic convenience. We study the case of the automated laboratory of one of the biggest hospital in Italy and compare the cost related to the pre and post automation situation. Introducing automation lead to a cost decrease without affecting the service level to patients

Clinical Laboratory Automation: A Case Study.

PubMed

Archetti, Claudia; Montanelli, Alessandro; Finazzi, Dario; Caimi, Luigi; Garrafa, Emirena

2017-04-13

This paper presents a case study of an automated clinical laboratory in a large urban academic teaching hospital in the North of Italy, the Spedali Civili in Brescia, where four laboratories were merged in a unique laboratory through the introduction of laboratory automation. The analysis compares the preautomation situation and the new setting from a cost perspective, by considering direct and indirect costs. It also presents an analysis of the turnaround time (TAT). The study considers equipment, staff and indirect costs. The introduction of automation led to a slight increase in equipment costs which is highly compensated by a remarkable decrease in staff costs. Consequently, total costs decreased by 12.55%. The analysis of the TAT shows an improvement of nonemergency exams while emergency exams are still validated within the maximum time imposed by the hospital. The strategy adopted by the management, which was based on re-using the available equipment and staff when merging the pre-existing laboratories, has reached its goal: introducing automation while minimizing the costs.

The Agriculture Model Intercomparison and Improvement Project (AgMIP) (Invited)

NASA Astrophysics Data System (ADS)

Rosenzweig, C.

2010-12-01

The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a distributed climate-scenario simulation exercise for historical model intercomparison and future climate change conditions with participation of multiple crop and world agricultural trade modeling groups around the world. The goals of AgMIP are to improve substantially the characterization of risk of hunger and world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Historical period results will spur model improvement and interaction among major modeling groups, while future period results will lead directly to tests of adaptation and mitigation strategies across a range of scales. AgMIP will consist of a multi-scale impact assessment utilizing the latest methods for climate and agricultural scenario generation. Scenarios and modeling protocols will be distributed on the web, and multi-model results will be collated and analyzed to ensure the widest possible coverage of agricultural crops and regions. AgMIP will place regional changes in agricultural production in a global context that reflects new trading opportunities, imbalances, and shortages in world markets resulting from climate change and other driving forces for food supply. Such projections are essential inputs from the Vulnerability, Impacts, and Adaptation (VIA) research community to the Intergovernmental Panel on Climate Change Fifth Assessment (AR5), now underway, and the UN Framework Convention on Climate Change. They will set the context for local-scale vulnerability and adaptation studies, supply test scenarios for national-scale development of trade policy instruments, provide critical information on changing supply and demand for water resources, and elucidate interactive effects of climate change and land use change. AgMIP will not only provide crucially-needed new global estimates of how climate change will affect food supply and hunger in the

A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of seventeen ice nucleation measurement techniques

NASA Astrophysics Data System (ADS)

Hiranuma, N.; Augustin-Bauditz, S.; Bingemer, H.; Budke, C.; Curtius, J.; Danielczok, A.; Diehl, K.; Dreischmeier, K.; Ebert, M.; Frank, F.; Hoffmann, N.; Kandler, K.; Kiselev, A.; Koop, T.; Leisner, T.; Möhler, O.; Nillius, B.; Peckhaus, A.; Rose, D.; Weinbruch, S.; Wex, H.; Boose, Y.; DeMott, P. J.; Hader, J. D.; Hill, T. C. J.; Kanji, Z. A.; Kulkarni, G.; Levin, E. J. T.; McCluskey, C. S.; Murakami, M.; Murray, B. J.; Niedermeier, D.; Petters, M. D.; O'Sullivan, D.; Saito, A.; Schill, G. P.; Tajiri, T.; Tolbert, M. A.; Welti, A.; Whale, T. F.; Wright, T. P.; Yamashita, K.

2014-08-01

Immersion freezing is the most relevant heterogeneous ice nucleation mechanism through which ice crystals are formed in mixed-phase clouds. In recent years, an increasing number of laboratory experiments utilizing a variety of instruments have examined immersion freezing activity of atmospherically relevant ice nucleating particles (INPs). However, an inter-comparison of these laboratory results is a difficult task because investigators have used different ice nucleation (IN) measurement methods to produce these results. A remaining challenge is to explore the sensitivity and accuracy of these techniques and to understand how the IN results are potentially influenced or biased by experimental parameters associated with these techniques. Within the framework of INUIT (Ice Nucleation research UnIT), we distributed an illite rich sample (illite NX) as a representative surrogate for atmospheric mineral dust particles to investigators to perform immersion freezing experiments using different IN measurement methods and to obtain IN data as a function of particle concentration, temperature (T), cooling rate and nucleation time. Seventeen measurement methods were involved in the data inter-comparison. Experiments with seven instruments started with the test sample pre-suspended in water before cooling, while ten other instruments employed water vapor condensation onto dry-dispersed particles followed by immersion freezing. The resulting comprehensive immersion freezing dataset was evaluated using the ice nucleation active surface-site density (ns) to develop a representative ns(T) spectrum that spans a wide temperature range (-37 °C < T < -11 °C) and covers nine orders of magnitude in ns. Our inter-comparison results revealed a discrepancy between suspension and dry-dispersed particle measurements for this mineral dust. While the agreement was good below ~ -26 °C, the ice nucleation activity, expressed in ns, was smaller for the wet suspended samples and higher for the

Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies

NASA Technical Reports Server (NTRS)

Eaton, L. R.; Greco, E. V.

1973-01-01

The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.

Intercomparison of techniques for the non-invasive measurement of bone mass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohn, S.H.

1981-01-01

A variety of methods are presently available for the non-invasive measurement of bone mass of both normal individuals and patients with metabolic disorders. Chief among these methods are radiographic techniques such as radiogrammetry, photon absorptiometry, computer tomography, Compton scattering and neutron activation analysis. In this review, the salient features of the bone measurement techniques are discussed along with their accuracy and precision. The advantages and disadvantages of the various techniques for measuring bone mass are summarized. Where possible, intercomparisons are made of the various techniques.

Inter-comparison of dynamic models for radionuclide transfer to marine biota in a Fukushima accident scenario.

PubMed

Vives I Batlle, J; Beresford, N A; Beaugelin-Seiller, K; Bezhenar, R; Brown, J; Cheng, J-J; Ćujić, M; Dragović, S; Duffa, C; Fiévet, B; Hosseini, A; Jung, K T; Kamboj, S; Keum, D-K; Kryshev, A; LePoire, D; Maderich, V; Min, B-I; Periáñez, R; Sazykina, T; Suh, K-S; Yu, C; Wang, C; Heling, R

2016-03-01

We report an inter-comparison of eight models designed to predict the radiological exposure of radionuclides in marine biota. The models were required to simulate dynamically the uptake and turnover of radionuclides by marine organisms. Model predictions of radionuclide uptake and turnover using kinetic calculations based on biological half-life (TB1/2) and/or more complex metabolic modelling approaches were used to predict activity concentrations and, consequently, dose rates of (90)Sr, (131)I and (137)Cs to fish, crustaceans, macroalgae and molluscs under circumstances where the water concentrations are changing with time. For comparison, the ERICA Tool, a model commonly used in environmental assessment, and which uses equilibrium concentration ratios, was also used. As input to the models we used hydrodynamic forecasts of water and sediment activity concentrations using a simulated scenario reflecting the Fukushima accident releases. Although model variability is important, the intercomparison gives logical results, in that the dynamic models predict consistently a pattern of delayed rise of activity concentration in biota and slow decline instead of the instantaneous equilibrium with the activity concentration in seawater predicted by the ERICA Tool. The differences between ERICA and the dynamic models increase the shorter the TB1/2 becomes; however, there is significant variability between models, underpinned by parameter and methodological differences between them. The need to validate the dynamic models used in this intercomparison has been highlighted, particularly in regards to optimisation of the model biokinetic parameters. Copyright © 2015 Elsevier Ltd. All rights reserved.

Water vapour inter-comparison effort in the framework of the hydrological cycle in the mediterranean experiment - special observation period (hymex-sop1)

NASA Astrophysics Data System (ADS)

Summa, Donato; Di Girolamo, Paolo; Flamant, Cyrille; De Rosa, Benedetto; Cacciani, Marco; Stelitano, Dario

2018-04-01

Accurate measurements of the vertical profiles of water vapour are of paramount importance for most key areas of atmospheric sciences. A comprehensive inter-comparison between different remote sensing and in-situ sensors has been carried out in the frame work of the first Special Observing Period of the Hydrological cycle in the Mediterranean Experiment for the purpose of obtaining accurate error estimates for these sensors. The inter-comparison involves a ground-based Raman lidar (BASIL), an airborne DIAL (LEANDRE2), a microwave radiometer, radiosondes and aircraft in-situ sensors.

Tethered gravity laboratories study

NASA Technical Reports Server (NTRS)

Lucchetti, F.

1989-01-01

Variable Gravity Laboratory studies are discussed. The following subject areas are covered: (1) conceptual design and engineering analysis; (2) control strategies (fast crawling maneuvers, main perturbations and their effect upon the acceleration level); and (3) technology requirements.

ACTRIS ACSM intercomparison - Part 2: Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

NASA Astrophysics Data System (ADS)

Fröhlich, R.; Crenn, V.; Setyan, A.; Belis, C. A.; Canonaco, F.; Favez, O.; Riffault, V.; Slowik, J. G.; Aas, W.; Aijälä, M.; Alastuey, A.; Artiñano, B.; Bonnaire, N.; Bozzetti, C.; Bressi, M.; Carbone, C.; Coz, E.; Croteau, P. L.; Cubison, M. J.; Esser-Gietl, J. K.; Green, D. C.; Gros, V.; Heikkinen, L.; Herrmann, H.; Jayne, J. T.; Lunder, C. R.; Minguillón, M. C.; Močnik, G.; O'Dowd, C. D.; Ovadnevaite, J.; Petralia, E.; Poulain, L.; Priestman, M.; Ripoll, A.; Sarda-Estève, R.; Wiedensohler, A.; Baltensperger, U.; Sciare, J.; Prévôt, A. S. H.

2015-06-01

Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSMs) performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM) from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM), and one high-resolution ToF aerosol mass spectrometer (AMS) were operated in parallel for about 3 weeks in November and December~2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF) utilising the multilinear engine 2 (ME-2). Except for the organic contribution of mass-to-charge ratio m/z 44 to the total organics (f44), which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f44 in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbon-like organic aerosol (HOA), cooking-related organic aerosol (COA), biomass burning-related organic aerosol (BBOA) and secondary oxygenated organic aerosol (OOA). ME-2 boundary conditions (profile constraints) were optimised individually by means of correlation to external data in order to achieve equivalent / comparable solutions for all ACSM instruments and the results are discussed together with the investigation of the influence of alternative anchors (reference profiles). A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative standard deviations (SD) from the mean between 13.7 and 22.7 % of the source's average mass contribution depending on the

Operational overview of the NASA GTE/CITE 3 airborne instrument intercomparisons for sulfur dioxide, hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, and carbon disulfide

NASA Technical Reports Server (NTRS)

Hoell, James M., Jr.; Davis, Douglas D.; Gregory, Gerald L.; Mcneal, Robert J.; Bendura, Richard J.; Drewry, Joseph W.; Barrick, John D.; Kirchhoff, Volker W. J. H.; Motta, Adauto G.; Navarro, Roger L.

1993-01-01

This paper reports the overall experimental design and gives a brief overview of results from the third airborne Chemical Instrumentation Test and Evaluation (CITE 3) mission conducted as part of the National Aeronautics and Space Administration's Global Tropospheric Experiment. The primary objective of CITE 3 was to evaluate the capability of instrumentation for airborne measurements of ambient concentrations of SO2, H2S, CS, dimethyl sulfide, and carbonyl sulfide. Ancillary measurements augmented the intercomparison data in order to address the secondary objective of CITE 3 which was to address specific issues related to the budget and photochemistry of tropospheric sulfur species. The CITE 3 mission was conducted on NASA's Wallops Flight Center Electra aircraft and included a ground-based intercomparison of sulfur standards and intercomparison/sulfur science flights conducted from the NASA Wallops Flight Facility, Wallops Island, Virginia, followed by flights from Natal, Brazil. Including the transit flights, CITE 3 included 16 flights encompassing approximately 96 flight hours.

Joint ARM/GCSS/SPARC TWP-ICE CRM Intercomparison Study: Description, Preliminary Results, and Invitation to Participate

NASA Astrophysics Data System (ADS)

Fridlind, A. M.; Ackerman, A. S.; Allen, G.; Beringer, J.; Comstock, J. M.; Field, P. R.; Gallagher, M.; Hacker, J. M.; Hume, T.; Jakob, C.; Liu, G.; Long, C. N.; Mather, J. H.; May, P. T.; McCoy, R. F.; McFarlane, S. A.; McFarquhar, G. M.; Minnis, P.; Petch, J. C.; Schumacher, C.; Turner, D. D.; Whiteway, J. A.; Williams, C. R.; Williams, P. I.; Xie, S.; Zhang, M.

2008-12-01

The 2006 Tropical Warm Pool - International Cloud Experiment (TWP-ICE) is 'the first field program in the tropics that attempted to describe the evolution of tropical convection, including the large-scale heat, moisture, and momentum budgets at 3-hourly time resolution, while at the same time obtaining detailed observations of cloud properties and the impact of the clouds on the environment' [May et al., 2008]. A cloud- resolving model (CRM) intercomparison based on TWP-ICE is now being undertaken by the Atmospheric Radiation Measurement (ARM), GEWEX Cloud Systems Study (GCSS), and Stratospheric Processes And their Role in Climate (SPARC) programs. We summarize the 16-day case study and the wealth of data being used to provide initial and boundary conditions, and evaluate some preliminary findings in the context of existing theories of moisture evolution in the tropical tropopause layer (TTL). Overall, simulated cloud fields evolve realistically by many measures. Budgets indicate that simulated convective flux convergence of water vapor is always positive or near zero at TTL elevations, except locally at lower levels during the driest suppressed monsoon conditions, while simulated water vapor deposition to hydrometeors always exceeds sublimation on average at all TTL elevations over 24-hour timescales. The next largest water vapor budget term is generally the nudging required to keep domain averages consistent with observations, which is at least partly attributable to large-scale forcing terms that cannot be derived from measurements. We discuss the primary uncertainties.

Intercomparison of CO 2 measurements

NASA Astrophysics Data System (ADS)

Poisson, A.; Culkin, F.; Ridout, P.

1990-10-01

Seawater samples, of four different salinities, were analysed for total alkalinity, total CO 2, pH and pCO 2 by up to 12 laboratories. The results showthat although most laboratories are capable of high precision in these determinations, there is an unacceptably high disagreement between their analyses of the same samples. For global programmes involving studies of the CO 2 system in seawater, it is strongly recommended that standard reference materials be made widely available.

Laboratory Plasma Studies

DTIC Science & Technology

1989-05-23

Intense Rela- tivistic Electron Beams S . A Compact Accelerator Powercd by the Relativistic Klystron Amplifier T. Numerical and Experimental Studies of...Research Laboratory Washingto, IX 2075.6000 NRL Memorandum Report 6419 Megavolt, Multi-Kiloamp K - Band Gyrotron Oscillator Experiment W. M. BLACK,* S . H...Ka- Band Gyrotron Oscillator Experiments with Slotted and Unslotted Cavities S . H. GOLD, MEMBER, IEEE. A. W. FLIFLET, MEMBER, IEEE, W. M. MANHEIMER

Analysis of uni and bi-parental markers in mixture samples: Lessons from the 22nd GHEP-ISFG Intercomparison Exercise.

PubMed

Toscanini, U; Gusmão, L; Álava Narváez, M C; Álvarez, J C; Baldassarri, L; Barbaro, A; Berardi, G; Betancor Hernández, E; Camargo, M; Carreras-Carbonell, J; Castro, J; Costa, S C; Coufalova, P; Domínguez, V; Fagundes de Carvalho, E; Ferreira, S T G; Furfuro, S; García, O; Goios, A; González, R; de la Vega, A González; Gorostiza, A; Hernández, A; Jiménez Moreno, S; Lareu, M V; León Almagro, A; Marino, M; Martínez, G; Miozzo, M C; Modesti, N M; Onofri, V; Pagano, S; Pardo Arias, B; Pedrosa, S; Penacino, G A; Pontes, M L; Porto, M J; Puente-Prieto, J; Pérez, R Ramírez; Ribeiro, T; Rodríguez Cardozo, B; Rodríguez Lesmes, Y M; Sala, A; Santiago, B; Saragoni, V G; Serrano, A; Streitenberger, E R; Torres Morales, M A; Vannelli Rey, S A; Velázquez Miranda, M; Whittle, M R; Fernández, K; Salas, A

2016-11-01

Since 1992, the Spanish and Portuguese-Speaking Working Group of the ISFG (GHEP-ISFG) has been organizing annual Intercomparison Exercises (IEs) coordinated by the Quality Service at the National Institute of Toxicology and Forensic Sciences (INTCF) from Madrid, aiming to provide proficiency tests for forensic DNA laboratories. Each annual exercise comprises a Basic (recently accredited under ISO/IEC 17043: 2010) and an Advanced Level, both including a kinship and a forensic module. Here, we show the results for both autosomal and sex-chromosomal STRs, and for mitochondrial DNA (mtDNA) in two samples included in the forensic modules, namely a mixture 2:1 (v/v) saliva/blood (M4) and a mixture 4:1 (v/v) saliva/semen (M8) out of the five items provided in the 2014 GHEP-ISFG IE. Discrepancies, other than typos or nomenclature errors (over the total allele calls), represented 6.5% (M4) and 4.7% (M8) for autosomal STRs, 15.4% (M4) and 7.8% (M8) for X-STRs, and 1.2% (M4) and 0.0% (M8) for Y-STRs. Drop-out and drop-in alleles were the main cause of errors, with laboratories using different criteria regarding inclusion of minor peaks and stutter bands. Commonly used commercial kits yielded different results for a micro-variant detected at locus D12S391. In addition, the analysis of electropherograms revealed that the proportions of the contributors detected in the mixtures varied among the participants. In regards to mtDNA analysis, besides important discrepancies in reporting heteroplasmies, there was no agreement for the results of sample M4. Thus, while some laboratories documented a single control region haplotype, a few reported unexpected profiles (suggesting contamination problems). For M8, most laboratories detected only the haplotype corresponding to the saliva. Although the GHEP-ISFG has already a large experience in IEs, the present multi-centric study revealed challenges that still exist related to DNA mixtures interpretation. Overall, the results emphasize the

High Resolution Model Intercomparison Project (HighResMIP v1.0) for CMIP6

NASA Astrophysics Data System (ADS)

Haarsma, Reindert J.; Roberts, Malcolm J.; Vidale, Pier Luigi; Senior, Catherine A.; Bellucci, Alessio; Bao, Qing; Chang, Ping; Corti, Susanna; Fučkar, Neven S.; Guemas, Virginie; von Hardenberg, Jost; Hazeleger, Wilco; Kodama, Chihiro; Koenigk, Torben; Leung, L. Ruby; Lu, Jian; Luo, Jing-Jia; Mao, Jiafu; Mizielinski, Matthew S.; Mizuta, Ryo; Nobre, Paulo; Satoh, Masaki; Scoccimarro, Enrico; Semmler, Tido; Small, Justin; von Storch, Jin-Song

2016-11-01

Robust projections and predictions of climate variability and change, particularly at regional scales, rely on the driving processes being represented with fidelity in model simulations. The role of enhanced horizontal resolution in improved process representation in all components of the climate system is of growing interest, particularly as some recent simulations suggest both the possibility of significant changes in large-scale aspects of circulation as well as improvements in small-scale processes and extremes. However, such high-resolution global simulations at climate timescales, with resolutions of at least 50 km in the atmosphere and 0.25° in the ocean, have been performed at relatively few research centres and generally without overall coordination, primarily due to their computational cost. Assessing the robustness of the response of simulated climate to model resolution requires a large multi-model ensemble using a coordinated set of experiments. The Coupled Model Intercomparison Project 6 (CMIP6) is the ideal framework within which to conduct such a study, due to the strong link to models being developed for the CMIP DECK experiments and other model intercomparison projects (MIPs). Increases in high-performance computing (HPC) resources, as well as the revised experimental design for CMIP6, now enable a detailed investigation of the impact of increased resolution up to synoptic weather scales on the simulated mean climate and its variability. The High Resolution Model Intercomparison Project (HighResMIP) presented in this paper applies, for the first time, a multi-model approach to the systematic investigation of the impact of horizontal resolution. A coordinated set of experiments has been designed to assess both a standard and an enhanced horizontal-resolution simulation in the atmosphere and ocean. The set of HighResMIP experiments is divided into three tiers consisting of atmosphere-only and coupled runs and spanning the period 1950-2050, with the

High Resolution Model Intercomparison Project (HighResMIP v1.0) for CMIP6

DOE PAGES

Haarsma, Reindert J.; Roberts, Malcolm J.; Vidale, Pier Luigi; ...

2016-11-22

Robust projections and predictions of climate variability and change, particularly at regional scales, rely on the driving processes being represented with fidelity in model simulations. The role of enhanced horizontal resolution in improved process representation in all components of the climate system is of growing interest, particularly as some recent simulations suggest both the possibility of significant changes in large-scale aspects of circulation as well as improvements in small-scale processes and extremes. However, such high-resolution global simulations at climate timescales, with resolutions of at least 50 km in the atmosphere and 0.25° in the ocean, have been performed at relativelymore » few research centres and generally without overall coordination, primarily due to their computational cost. Assessing the robustness of the response of simulated climate to model resolution requires a large multi-model ensemble using a coordinated set of experiments. The Coupled Model Intercomparison Project 6 (CMIP6) is the ideal framework within which to conduct such a study, due to the strong link to models being developed for the CMIP DECK experiments and other model intercomparison projects (MIPs). Increases in high-performance computing (HPC) resources, as well as the revised experimental design for CMIP6, now enable a detailed investigation of the impact of increased resolution up to synoptic weather scales on the simulated mean climate and its variability. The High Resolution Model Intercomparison Project (HighResMIP) presented in this paper applies, for the first time, a multi-model approach to the systematic investigation of the impact of horizontal resolution. A coordinated set of experiments has been designed to assess both a standard and an enhanced horizontal-resolution simulation in the atmosphere and ocean. The set of HighResMIP experiments is divided into three tiers consisting of atmosphere-only and coupled runs and spanning the period 1950�

Intercomparison Between Microwave Radiometer and Radiosonding Data

NASA Astrophysics Data System (ADS)

Toanca, Florica; Stefan, Sabina

2014-05-01

The aim of this study is to compare relative humidity and temperature vertical profiles measured by ground based Microwave Radiometer (MWR) RPG HATPRO installed at the Romanian Atmospheric Observatory (Magurele, 44.35 N, 26.03 E) and by radio-sounding (RS) (Baneasa, 44.30 N, 26.04 E) provided by National Meteorological Administration. MWR uses passive microwave detection in the 22.335 to 31.4 GHz and 51to 58 GHz bands to obtain the vertical profiles of temperature and relative humidity up to 10km with a temporal resolution of several minutes. The reliability of atmospheric temperature and relative humidity profiles retrieved continuously by the MWR for the winter and summer of year 2013 was studied. The study was conducted, comparing the temperature and humidity profiles from the MWR with the ones from the radio soundings at 0:00 a.m. Two datasets of the humidity show a fairly good agreement for the interval between ground and 1.5 km in the January month for winter and up to 2 km in the July month for summer. Above 2 km, for the both seasons, the humidity profiles present in most of the selected cases the same trend evolution. The temperature vertical profiles agreed in 95% of the cases during summer and 85% during winter. It is very important for intercomparison that for both seasons almost all temperature vertical profiles highlight temperature inversions. Two cases have been analyzed in order to find possible explanations for the discrepancies between vertical profiles, focusing on advantages and disadvantages of MWR measurements.

Impact of Spatial Scales on the Intercomparison of Climate Scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Wei; Steptoe, Michael; Chang, Zheng

2017-01-01

Scenario analysis has been widely applied in climate science to understand the impact of climate change on the future human environment, but intercomparison and similarity analysis of different climate scenarios based on multiple simulation runs remain challenging. Although spatial heterogeneity plays a key role in modeling climate and human systems, little research has been performed to understand the impact of spatial variations and scales on similarity analysis of climate scenarios. To address this issue, the authors developed a geovisual analytics framework that lets users perform similarity analysis of climate scenarios from the Global Change Assessment Model (GCAM) using a hierarchicalmore » clustering approach.« less

Intercomparison of SO2 camera systems for imaging volcanic gas plumes

USGS Publications Warehouse

Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-Francois; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

2015-01-01

SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans - joint RENEB and EURADOS inter-laboratory comparisons.

PubMed

Ainsbury, Elizabeth; Badie, Christophe; Barnard, Stephen; Manning, Grainne; Moquet, Jayne; Abend, Michael; Antunes, Ana Catarina; Barrios, Lleonard; Bassinet, Celine; Beinke, Christina; Bortolin, Emanuela; Bossin, Lily; Bricknell, Clare; Brzoska, Kamil; Buraczewska, Iwona; Castaño, Carlos Huertas; Čemusová, Zina; Christiansson, Maria; Cordero, Santiago Mateos; Cosler, Guillaume; Monaca, Sara Della; Desangles, François; Discher, Michael; Dominguez, Inmaculada; Doucha-Senf, Sven; Eakins, Jon; Fattibene, Paola; Filippi, Silvia; Frenzel, Monika; Georgieva, Dimka; Gregoire, Eric; Guogyte, Kamile; Hadjidekova, Valeria; Hadjiiska, Ljubomira; Hristova, Rositsa; Karakosta, Maria; Kis, Enikő; Kriehuber, Ralf; Lee, Jungil; Lloyd, David; Lumniczky, Katalin; Lyng, Fiona; Macaeva, Ellina; Majewski, Matthaeus; Vanda Martins, S; McKeever, Stephen W S; Meade, Aidan; Medipally, Dinesh; Meschini, Roberta; M'kacher, Radhia; Gil, Octávia Monteiro; Montero, Alegria; Moreno, Mercedes; Noditi, Mihaela; Oestreicher, Ursula; Oskamp, Dominik; Palitti, Fabrizio; Palma, Valentina; Pantelias, Gabriel; Pateux, Jerome; Patrono, Clarice; Pepe, Gaetano; Port, Matthias; Prieto, María Jesús; Quattrini, Maria Cristina; Quintens, Roel; Ricoul, Michelle; Roy, Laurence; Sabatier, Laure; Sebastià, Natividad; Sholom, Sergey; Sommer, Sylwester; Staynova, Albena; Strunz, Sonja; Terzoudi, Georgia; Testa, Antonella; Trompier, Francois; Valente, Marco; Hoey, Olivier Van; Veronese, Ivan; Wojcik, Andrzej; Woda, Clemens

2017-01-01

RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation-induced thermoluminescent signals in glass screens taken from mobile phones. In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios.

The Pliocene Model Intercomparison Project (PlioMIP) Phase 2: scientific objectives and experimental design

NASA Astrophysics Data System (ADS)

Haywood, Alan M.; Dowsett, Harry J.; Dolan, Aisling M.; Rowley, David; Abe-Ouchi, Ayako; Otto-Bliesner, Bette; Chandler, Mark A.; Hunter, Stephen J.; Lunt, Daniel J.; Pound, Matthew; Salzmann, Ulrich

2016-03-01

The Pliocene Model Intercomparison Project (PlioMIP) is a co-ordinated international climate modelling initiative to study and understand climate and environments of the Late Pliocene, as well as their potential relevance in the context of future climate change. PlioMIP examines the consistency of model predictions in simulating Pliocene climate and their ability to reproduce climate signals preserved by geological climate archives. Here we provide a description of the aim and objectives of the next phase of the model intercomparison project (PlioMIP Phase 2), and we present the experimental design and boundary conditions that will be utilized for climate model experiments in Phase 2. Following on from PlioMIP Phase 1, Phase 2 will continue to be a mechanism for sampling structural uncertainty within climate models. However, Phase 1 demonstrated the requirement to better understand boundary condition uncertainties as well as uncertainty in the methodologies used for data-model comparison. Therefore, our strategy for Phase 2 is to utilize state-of-the-art boundary conditions that have emerged over the last 5 years. These include a new palaeogeographic reconstruction, detailing ocean bathymetry and land-ice surface topography. The ice surface topography is built upon the lessons learned from offline ice sheet modelling studies. Land surface cover has been enhanced by recent additions of Pliocene soils and lakes. Atmospheric reconstructions of palaeo-CO2 are emerging on orbital timescales, and these are also incorporated into PlioMIP Phase 2. New records of surface and sea surface temperature change are being produced that will be more temporally consistent with the boundary conditions and forcings used within models. Finally we have designed a suite of prioritized experiments that tackle issues surrounding the basic understanding of the Pliocene and its relevance in the context of future climate change in a discrete way.

The Pliocene Model Intercomparison Project (PlioMIP) Phase 2: Scientific Objectives and Experimental Design

NASA Technical Reports Server (NTRS)

Haywood, Alan M.; Dowsett, Harry J.; Dolan, Aisling M.; Rowley, David; Abe-Ouchi, Ayako; Otto-Bliesner, Bette; Chandler, Mark A.; Hunter, Stephen J.; Lunt, Daniel J.; Pound, Matthew;

Inter-comparison of GRACE data over India

NASA Astrophysics Data System (ADS)

Banerjee, Chandan; Kumar, D. Nagesh

2016-05-01

The advent of satellite remote sensing and its use in hydrology has facilitated a huge leap in the understanding of the various water resources, its interaction with ecological systems and anthropogenic creations. Recently, NASA and German Aerospace Research Agency-DLR launched the Gravity Recovery and Climate Experiment (GRACE) satellite mission consisting of two satellites. They measure the time varying gravity which gives changes in the distribution of mass on the surface of the earth which after removing atmospheric and oceanic effects is majorly caused by changes in Terrestrial Water Storage (TWS) changes. GRACE data is generally available as spherical harmonic coefficients, which is difficult for hydrologists to understand and interpret. JPL's TELLUS website is now providing gridded global data set in the form of mass anomaly derived from the Level-2 data sets of spherical harmonic coefficients of 3 sources, viz. CSR, GFZ and JPL. Before using these data sets for solving hydrological problems, it is important to understand the differences and similarities between these data sets as direct calibration of GRACE data is not possible. In this study we do an inter-comparison of the Level-3 Release 05 data sets over India. We compare the data sets using Pearson, Spearman and Kendall correlation. CSR and GFZ data sets appear to be closest to each other whereas JPL and GFZ data sets are most different from each other.

Intercomparison of Laboratory Radiance Calibration Standards

NASA Technical Reports Server (NTRS)

Pavri, Betina; Chrien, Tom; Green, Robert; Williams, Orlesa

2000-01-01

Several standards for radiometric calibration were measured repeatedly with a spectroradiometer in order to understand how they compared in accuracy and stability. The tested radiance standards included a NIST 1000 W bulb and halon panel, two calibrated and stabilized integrating spheres, and a cavity blackbody. Results indicate good agreement between the blackbody and 1000 W bulb/spectralon panel, If these two radiance sources are assumed correct, then the integrating spheres did not conform. to their manufacturer-reported radiances in several regions of the spectrum. More detailed measurements am underway to investigate the discrepancy.

Biogeochemical Protocols and Diagnostics for the CMIP6 Ocean Model Intercomparison Project (OMIP)

NASA Technical Reports Server (NTRS)

Orr, James C.; Najjar, Raymond G.; Aumont, Olivier; Bopp, Laurent; Bullister, John L.; Danabasoglu, Gokhan; Doney, Scott C.; Dunne, John P.; Dutay, Jean-Claude; Graven, Heather;

Biogeochemical protocols and diagnostics for the CMIP6 Ocean Model Intercomparison Project (OMIP)

NASA Astrophysics Data System (ADS)

Orr, James C.; Najjar, Raymond G.; Aumont, Olivier; Bopp, Laurent; Bullister, John L.; Danabasoglu, Gokhan; Doney, Scott C.; Dunne, John P.; Dutay, Jean-Claude; Graven, Heather; Griffies, Stephen M.; John, Jasmin G.; Joos, Fortunat; Levin, Ingeborg; Lindsay, Keith; Matear, Richard J.; McKinley, Galen A.; Mouchet, Anne; Oschlies, Andreas; Romanou, Anastasia; Schlitzer, Reiner; Tagliabue, Alessandro; Tanhua, Toste; Yool, Andrew

2017-06-01

The Ocean Model Intercomparison Project (OMIP) focuses on the physics and biogeochemistry of the ocean component of Earth system models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6). OMIP aims to provide standard protocols and diagnostics for ocean models, while offering a forum to promote their common assessment and improvement. It also offers to compare solutions of the same ocean models when forced with reanalysis data (OMIP simulations) vs. when integrated within fully coupled Earth system models (CMIP6). Here we detail simulation protocols and diagnostics for OMIP's biogeochemical and inert chemical tracers. These passive-tracer simulations will be coupled to ocean circulation models, initialized with observational data or output from a model spin-up, and forced by repeating the 1948-2009 surface fluxes of heat, fresh water, and momentum. These so-called OMIP-BGC simulations include three inert chemical tracers (CFC-11, CFC-12, SF6) and biogeochemical tracers (e.g., dissolved inorganic carbon, carbon isotopes, alkalinity, nutrients, and oxygen). Modelers will use their preferred prognostic BGC model but should follow common guidelines for gas exchange and carbonate chemistry. Simulations include both natural and total carbon tracers. The required forced simulation (omip1) will be initialized with gridded observational climatologies. An optional forced simulation (omip1-spunup) will be initialized instead with BGC fields from a long model spin-up, preferably for 2000 years or more, and forced by repeating the same 62-year meteorological forcing. That optional run will also include abiotic tracers of total dissolved inorganic carbon and radiocarbon, CTabio and 14CTabio, to assess deep-ocean ventilation and distinguish the role of physics vs. biology. These simulations will be forced by observed atmospheric histories of the three inert gases and CO2 as well as carbon isotope ratios of CO2. OMIP-BGC simulation protocols are

The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

DOE PAGES

O'Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.; ...

2016-09-28

Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. Here, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide rangemore » of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. Furthermore, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2°C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. In order to serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially explicit

The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.

2016-01-01

Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate amore » wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially

The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

NASA Astrophysics Data System (ADS)

O'Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.; Eyring, Veronika; Friedlingstein, Pierre; Hurtt, George; Knutti, Reto; Kriegler, Elmar; Lamarque, Jean-Francois; Lowe, Jason; Meehl, Gerald A.; Moss, Richard; Riahi, Keywan; Sanderson, Benjamin M.

2016-09-01

Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially explicit

NASA Giovanni Portals for NLDAS/GLDAS Online Visualization, Analysis, and Intercomparison

NASA Technical Reports Server (NTRS)

Rui, Hualan; Teng, William L.; Vollmer, Bruce; Mocko, David M.; Beaudoing, Hiroko Kato; Rodell, Matthew

2011-01-01

The North American Land Data Assimilation System (NLDAS) and Global Land Data Assimilation System (GLDAS) are generating a series of land surface forcing (e.g., precipitation, surface meteorology, and radiation), state (e.g., soil moisture and temperature, and snow), and flux (e.g., evaporation and sensible heat flux) products, simulated by several land surface models. To date, NLDAS and GLDAS have generated more than 30 (1979 - present) and 60 (1948 - present) years of data, respectively. To further facilitate data accessibility and utilization, three new portals in the NASA Giovanni system have been made available for NLDAS and GLDAS online visualization, analysis, and intercomparison.

The ENEA criticality accident dosimetry system: a contribution to the 2002 international intercomparison at the SILENE reactor.

PubMed

Gualdrini, G; Bedogni, R; Fantuzzi, E; Mariotti, F

2004-01-01

The present paper summarises the activity carried out at the ENEA Radiation Protection Institute for updating the methodologies employed for the evaluation of the neutron and photon dose to the exposed workers in case of a criticality accident, in the framework of the 'International Intercomparison of Criticality Accident Dosimetry Systems' (Silène reactor, IRSN-CEA-Valduc June 2002). The evaluation of the neutron spectra and the neutron dosimetric quantities relies on activation detectors and on unfolding algorithms. Thermoluminescent detectors are employed for the gamma dose measurement. The work is aimed at accurately characterising the measurement system and, at the same time, testing the algorithms. Useful spectral information were included, based on Monte Carlo simulations, to take into account the potential accident scenarios of practical interest. All along this exercise intercomparison a particular attention was devoted to the 'traceability' of all the experimental and computational parameters and therefore, aimed at an easy treatment by the user.

Intercomparisons of nine sky brightness detectors.

PubMed

den Outer, Peter; Lolkema, Dorien; Haaima, Marty; van der Hoff, Rene; Spoelstra, Henk; Schmidt, Wim

2011-01-01

Nine Sky Quality Meters (SQMs) have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across The Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between ±14%. Individual night time sums range from -16% to +20%. Intercalibration reduces this to 0.5%, and -7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 ± 0.003 mcd/m(2) on 12 April, and the largest value was 5.94 ± 0.03 mcd/m(2) on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.

Radiative-convective equilibrium model intercomparison project

NASA Astrophysics Data System (ADS)

Wing, Allison A.; Reed, Kevin A.; Satoh, Masaki; Stevens, Bjorn; Bony, Sandrine; Ohno, Tomoki

2018-03-01

RCEMIP, an intercomparison of multiple types of models configured in radiative-convective equilibrium (RCE), is proposed. RCE is an idealization of the climate system in which there is a balance between radiative cooling of the atmosphere and heating by convection. The scientific objectives of RCEMIP are three-fold. First, clouds and climate sensitivity will be investigated in the RCE setting. This includes determining how cloud fraction changes with warming and the role of self-aggregation of convection in climate sensitivity. Second, RCEMIP will quantify the dependence of the degree of convective aggregation and tropical circulation regimes on temperature. Finally, by providing a common baseline, RCEMIP will allow the robustness of the RCE state across the spectrum of models to be assessed, which is essential for interpreting the results found regarding clouds, climate sensitivity, and aggregation, and more generally, determining which features of tropical climate a RCE framework is useful for. A novel aspect and major advantage of RCEMIP is the accessibility of the RCE framework to a variety of models, including cloud-resolving models, general circulation models, global cloud-resolving models, single-column models, and large-eddy simulation models.

An assessment of two automated snow water equivalent instruments during the WMO Solid Precipitation Intercomparison Experiment

NASA Astrophysics Data System (ADS)

Smith, Craig D.; Kontu, Anna; Laffin, Richard; Pomeroy, John W.

2017-01-01

During the World Meteorological Organization (WMO) Solid Precipitation Intercomparison Experiment (SPICE), automated measurements of snow water equivalent (SWE) were made at the Sodankylä (Finland), Weissfluhjoch (Switzerland) and Caribou Creek (Canada) SPICE sites during the northern hemispheric winters of 2013/14 and 2014/15. Supplementary intercomparison measurements were made at Fortress Mountain (Kananaskis, Canada) during the 2013/14 winter. The objectives of this analysis are to compare automated SWE measurements with a reference, comment on their performance and, where possible, to make recommendations on how to best use the instruments and interpret their measurements. Sodankylä, Caribou Creek and Fortress Mountain hosted a Campbell Scientific CS725 passive gamma radiation SWE sensor. Sodankylä and Weissfluhjoch hosted a Sommer Messtechnik SSG1000 snow scale. The CS725 operating principle is based on measuring the attenuation of soil emitted gamma radiation by the snowpack and relating the attenuation to SWE. The SSG1000 measures the mass of the overlying snowpack directly by using a weighing platform and load cell. Manual SWE measurements were obtained at the intercomparison sites on a bi-weekly basis over the accumulation-ablation periods using bulk density samplers. These manual measurements are considered to be the reference for the intercomparison. Results from Sodankylä and Caribou Creek showed that the CS725 generally overestimates SWE as compared to manual measurements by roughly 30-35 % with correlations (r2) as high as 0.99 for Sodankylä and 0.90 for Caribou Creek. The RMSE varied from 30 to 43 mm water equivalent (mm w.e.) and from 18 to 25 mm w.e. at Sodankylä and Caribou Creek, which had respective SWE maximums of approximately 200 and 120 mm w.e. The correlation at Fortress Mountain was 0.94 (RMSE of 48 mm w.e. with a maximum SWE of approximately 650 mm w.e.) with no systematic overestimation. The SSG1000 snow scale, having a different

Intercomparison of photon dose measurements at the 8 MeV electron accelerator

NASA Astrophysics Data System (ADS)

Angelescu, T.; Ghiordănescu, N.; Băl ţă ţeanu, N.; Labău, V.; Vasilescu, A.

1997-02-01

Measurements of dose with thermoluminescent detectors (TLD) and an ionisation chamber were performed in the range of 5-70 Gy in the electron bremsstrahlung field with a maximum energy of 8 MeV of the Bucharest linear accelerator. Previous calibration was done with a 60Co source. The results of the intercomparison were used in dosimetry of the n - γ field of the ΣΣ irradiation facility, with a photon spectrum similar to the 8 MeV bremsstrahlung field [T. Angelescu et al., Nucl. Instr. and Meth. A 378 (1996) 594].

Intercomparison of two comparative reactivity method instruments inf the Mediterranean basin during summer 2013

NASA Astrophysics Data System (ADS)

Zannoni, N.; Dusanter, S.; Gros, V.; Sarda Esteve, R.; Michoud, V.; Sinha, V.; Locoge, N.; Bonsang, B.

2015-09-01

The hydroxyl radical (OH) plays a key role in the atmosphere, as it initiates most of the oxidation processes of volatile organic compounds (VOCs), and can ultimately lead to the formation of ozone and secondary organic aerosols (SOAs). There are still uncertainties associated with the OH budget assessed using current models of atmospheric chemistry and direct measurements of OH sources and sinks have proved to be valuable tools to improve our understanding of the OH chemistry. The total first order loss rate of OH, or total OH reactivity, can be directly measured using three different methods, such as the following: total OH loss rate measurement, laser-induced pump and probe technique and comparative reactivity method. Observations of total OH reactivity are usually coupled to individual measurements of reactive compounds in the gas phase, which are used to calculate the OH reactivity. Studies using the three methods have highlighted that a significant fraction of OH reactivity is often not explained by individually measured reactive compounds and could be associated to unmeasured or unknown chemical species. Therefore accurate and reproducible measurements of OH reactivity are required. The comparative reactivity method (CRM) has demonstrated to be an advantageous technique with an extensive range of applications, and for this reason it has been adopted by several research groups since its development. However, this method also requires careful corrections to derive ambient OH reactivity. Herein we present an intercomparison exercise of two CRM instruments, CRM-LSCE (Laboratoire des Sciences du Climat et de l'Environnement) and CRM-MD (Mines Douai), conducted during July 2013 at the Mediterranean site of Ersa, Cape Corsica, France. The intercomparison exercise included tests to assess the corrections needed by the two instruments to process the raw data sets as well as OH reactivity observations. The observation was divided in three parts: 2 days of plant

Intercomparison and validation of MODIS and GLASS leaf area index (LAI) products over mountain areas: A case study in southwestern China

NASA Astrophysics Data System (ADS)

Jin, Huaan; Li, Ainong; Bian, Jinhu; Nan, Xi; Zhao, Wei; Zhang, Zhengjian; Yin, Gaofei

2017-03-01

The validation study of leaf area index (LAI) products over rugged surfaces not only gives additional insights into data quality of LAI products, but deepens understanding of uncertainties regarding land surface process models depended on LAI data over complex terrain. This study evaluated the performance of MODIS and GLASS LAI products using the intercomparison and direct validation methods over southwestern China. The spatio-temporal consistencies, such as the spatial distributions of LAI products and their statistical relationship as a function of topographic indices, time, and vegetation types, respectively, were investigated through intercomparison between MODIS and GLASS products during the period 2011-2013. The accuracies and change ranges of these two products were evaluated against available LAI reference maps over 10 sampling regions which standed for typical vegetation types and topographic gradients in southwestern China. The results show that GLASS LAI exhibits higher percentage of good quality data (i.e. successful retrievals) and smoother temporal profiles than MODIS LAI. The percentage of successful retrievals for MODIS and GLASS is vulnerable to topographic indices, especially to relief amplitude. Besides, the two products do not capture seasonal dynamics of crop, especially in spring over heterogeneously hilly regions. The yearly mean LAI differences between MODIS and GLASS are within ±0.5 for 64.70% of the total retrieval pixels over southwestern China. The spatial distribution of mean differences and temporal profiles of these two products are inclined to be dominated by vegetation types other than topographic indices. The spatial and temporal consistency of these two products is good over most area of grasses/cereal crops; however, it is poor for evergreen broadleaf forest. MODIS presents more reliable change range of LAI than GLASS through comparison with fine resolution reference maps over most of sampling regions. The accuracies of direct

Inter-Comparison of GOES-8 Imager and Sounder Skin Temperature Retrievals

NASA Technical Reports Server (NTRS)

Haines, Stephanie L.; Suggs, Ronnie J.; Jedlovec, Gary J.; Arnold, James E. (Technical Monitor)

2001-01-01

Skin temperature (ST) retrievals derived from geostationary satellite observations have both high temporal and spatial resolutions and are therefore useful for applications such as assimilation into mesoscale forecast models, nowcasting, and diagnostic studies. Our retrieval method uses a Physical Split Window technique requiring at least two channels within the longwave infrared window. On current GOES satellites, including GOES-11, there are two Imager channels within the required spectral interval. However, beginning with the GOES-M satellite the 12-um channel will be removed, leaving only one longwave channel. The Sounder instrument will continue to have three channels within the longwave window, and therefore ST retrievals will be derived from Sounder measurements. This research compares retrievals from the two instruments and evaluates the effects of the spatial resolution and sensor calibration differences on the retrievals. Both Imager and Sounder retrievals are compared to ground-truth data to evaluate the overall accuracy of the technique. An analysis of GOES-8 and GOES-11 intercomparisons is also presented.

GCSS/WGNE Pacific Cross-section Intercomparison: Tropical and Subtropical Cloud Transitions

NASA Astrophysics Data System (ADS)

Teixeira, J.

2008-12-01

In this presentation I will discuss the role of the GEWEX Cloud Systems Study (GCSS) working groups in paving the way for substantial improvements in cloud parameterization in weather and climate models. The GCSS/WGNE Pacific Cross-section Intercomparison (GPCI) is an extension of GCSS and is a different type of model evaluation where climate models are analyzed along a Pacific Ocean transect from California to the equator. This approach aims at complementing the more traditional efforts in GCSS by providing a simple framework for the evaluation of models that encompasses several fundamental cloud regimes such as stratocumulus, shallow cumulus and deep cumulus, as well as the transitions between them. Currently twenty four climate and weather prediction models are participating in GPCI. We will present results of the comparison between models and recent satellite data. In particular, we will explore in detail the potential of the Atmospheric Infrared Sounder (AIRS) and CloudSat data for the evaluation of the representation of clouds and convection in climate models.

Microdosimetric intercomparison of BNCT beams at BNL and MIT.

PubMed

Burmeister, Jay; Riley, Kent; Coderre, Jeffrey A; Harling, Otto K; Ma, Ruimei; Wielopolski, Lucian; Kota, Chandrasekhar; Maughan, Richard L

2003-08-01

Microdosimetric measurements have been performed at the clinical beam intensities in two epithermal neutron beams, the Brookhaven Medical Research Reactor and the M67 beam at the Massachusetts Institute of Technology Research Reactor, which have been used to treat patients with Boron Neutron Capture Therapy (BNCT). These measurements offer an independent assessment of the dosimetry used at these two facilities, as well as provide information about the radiation quality not obtainable from conventional macrodosimetric techniques. Moreover, they provide a direct measurement of the absorbed dose resulting from the BNC reaction. BNC absorbed doses measured within this study are approximately 15% lower than those estimated using foil activation at both MIT and BNL. Finally, an intercomparison of the characteristics and radiation quality of these two clinical beams is presented. The techniques described here allow an accurate quantitative comparison of the physical absorbed dose as well as a measure of the biological effectiveness of the absorbed dose delivered by different epithermal beams. No statistically significant differences were observed in the predicted RBEs of these two beams. The methodology presented here can help to facilitate the effective sharing of clinical results in an effort to demonstrate the clinical utility of BNCT.

Landsat 8 Remote Sensing Reflectance (Rrs) Products: Evaluations, Intercomparisons, and Enhancements

NASA Technical Reports Server (NTRS)

Pahlevan, Nima; Schott, John R.; Franz, Bryan A.; Zibordi, Giuseppe; Markham, Brian; Bailey, Sean; Schaaf, Crystal B.; Ondrusek, Michael; Greb, Steven; Strait, Christopher M.

2017-01-01

The Operational Land Imager (OLI) onboard Landsat-8 is generating high-quality aquatic science products, the most critical of which is the remote sensing reflectance (Rrs), defined as the ratio of water-leaving radiance to the total downwelling irradiance just above water. The quality of the Rrs products has not, however, been extensively assessed. This manuscript provides a comprehensive evaluation of Level-1B, i.e., top of atmosphere reflectance, and Rrs products available from OLI imagery under near-ideal atmospheric conditions in moderately turbid waters. The procedure includes a) evaluations of the Rrs products at sites included in the Ocean Color component of the Aerosol Robotic Network (AERONET-OC), b) intercomparisons and cross-calibrations against other ocean color products, and c) optimizations of vicarious calibration gains across the entire OLI observing swath. Results indicate that the near-infrared and shortwave infrared (NIR-SWIR) band combinations yield the most robust and stable Rrs retrievals in moderately turbid waters. Intercomparisons against products derived from the Visible Infrared Imaging Radiometer Suite (VIIRS) and the Moderate Resolution Imaging Spectroradiometer onboard the Aqua platform (MODISA) indicate slight across-track non-uniformities (<1%) associated with OLI scenes in the blue bands. In both product domains (TOA and Rrs), on average, the OLI products were found larger in radiometric responses in the blue channels. Following the implementation of updated vicarious calibration gains and accounting for across-track non-uniformities, matchup analyses using independent in-situ validation data confirmed improvements in Rrs products. These findings further support high-fidelity OLI-derived aquatic science products in terms of both demonstrating a robust atmospheric correction method and providing consistent products across OLI's imaging swath.

C4MIP – The Coupled Climate–Carbon Cycle Model Intercomparison Project: Experimental protocol for CMIP6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Chris D.; Arora, Vivek; Friedlingstein, Pierre

Coordinated experimental design and implementation has become a cornerstone of global climate modelling. Model Intercomparison Projects (MIPs) enable systematic and robust analysis of results across many models, by reducing the influence of ad hoc differences in model set-up or experimental boundary conditions. As it enters its 6th phase, the Coupled Model Intercomparison Project (CMIP6) has grown significantly in scope with the design and documentation of individual simulations delegated to individual climate science communities. The Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP) takes responsibility for design, documentation, and analysis of carbon cycle feedbacks and interactions in climate simulations. These feedbacks aremore » potentially large and play a leading-order contribution in determining the atmospheric composition in response to human emissions of CO 2 and in the setting of emissions targets to stabilize climate or avoid dangerous climate change. For over a decade, C4MIP has coordinated coupled climate–carbon cycle simulations, and in this paper we describe the C4MIP simulations that will be formally part of CMIP6. While the climate–carbon cycle community has created this experimental design, the simulations also fit within the wider CMIP activity, conform to some common standards including documentation and diagnostic requests, and are designed to complement the CMIP core experiments known as the Diagnostic, Evaluation and Characterization of Klima (DECK). C4MIP has three key strands of scientific motivation and the requested simulations are designed to satisfy their needs: (1) pre-industrial and historical simulations (formally part of the common set of CMIP6 experiments) to enable model evaluation, (2) idealized coupled and partially coupled simulations with 1 % per year increases in CO 2 to enable diagnosis of feedback strength and its components, (3) future scenario simulations to project how the Earth system will

C4MIP – The Coupled Climate–Carbon Cycle Model Intercomparison Project: Experimental protocol for CMIP6

DOE PAGES

Jones, Chris D.; Arora, Vivek; Friedlingstein, Pierre; ...

2016-08-25

Coordinated experimental design and implementation has become a cornerstone of global climate modelling. Model Intercomparison Projects (MIPs) enable systematic and robust analysis of results across many models, by reducing the influence of ad hoc differences in model set-up or experimental boundary conditions. As it enters its 6th phase, the Coupled Model Intercomparison Project (CMIP6) has grown significantly in scope with the design and documentation of individual simulations delegated to individual climate science communities. The Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP) takes responsibility for design, documentation, and analysis of carbon cycle feedbacks and interactions in climate simulations. These feedbacks aremore » potentially large and play a leading-order contribution in determining the atmospheric composition in response to human emissions of CO 2 and in the setting of emissions targets to stabilize climate or avoid dangerous climate change. For over a decade, C4MIP has coordinated coupled climate–carbon cycle simulations, and in this paper we describe the C4MIP simulations that will be formally part of CMIP6. While the climate–carbon cycle community has created this experimental design, the simulations also fit within the wider CMIP activity, conform to some common standards including documentation and diagnostic requests, and are designed to complement the CMIP core experiments known as the Diagnostic, Evaluation and Characterization of Klima (DECK). C4MIP has three key strands of scientific motivation and the requested simulations are designed to satisfy their needs: (1) pre-industrial and historical simulations (formally part of the common set of CMIP6 experiments) to enable model evaluation, (2) idealized coupled and partially coupled simulations with 1 % per year increases in CO 2 to enable diagnosis of feedback strength and its components, (3) future scenario simulations to project how the Earth system will

Tethered gravity laboratories study

NASA Technical Reports Server (NTRS)

Lucchetti, F.

1990-01-01

The scope of the study is to investigate ways of controlling the microgravity environment of the International Space Station by means of a tethered system. Four main study tasks were performed. First, researchers analyzed the utilization of the tether systems to improve the lowest possible steady gravity level on the Space Station and the tether capability to actively control the center of gravity position in order to compensate for activities that would upset the mass distribution of the Station. The purpose of the second task was to evaluate the whole of the experiments performable in a variable gravity environment and the related beneficial residual accelerations, both for pure and applied research in the fields of fluid, materials, and life science, so as to assess the relevance of a variable g-level laboratory. The third task involves the Tethered Variable Gravity Laboratory. The use of the facility that would crawl along a deployed tether and expose experiments to varying intensities of reduced gravity is discussed. Last, a study performed on the Attitude Tether Stabilizer concept is discussed. The stabilization effect of ballast masses tethered to the Space Station was investigated as a means of assisting the attitude control system of the Station.

Human Laboratory Studies on Cannabinoids and Psychosis.

PubMed

Sherif, Mohamed; Radhakrishnan, Rajiv; D'Souza, Deepak Cyril; Ranganathan, Mohini

2016-04-01

Some of the most compelling evidence supporting an association between cannabinoid agonists and psychosis comes from controlled laboratory studies in humans. Randomized, double-blind, placebo-controlled, crossover laboratory studies demonstrate that cannabinoid agonists, including phytocannabinoids and synthetic cannabinoids, produce a wide range of positive, negative, and cognitive symptoms and psychophysiologic deficits in healthy human subjects that resemble the phenomenology of schizophrenia. These effects are time locked to drug administration, are dose related, and are transient and rarely necessitate intervention. The magnitude of effects is similar to the effects of ketamine but qualitatively distinct from other psychotomimetic drugs, including ketamine, amphetamine, and salvinorin A. Cannabinoid agonists have also been shown to transiently exacerbate symptoms in individuals with schizophrenia in laboratory studies. Patients with schizophrenia are more vulnerable than healthy control subjects to the acute behavioral and cognitive effects of cannabinoid agonists and experience transient exacerbation of symptoms despite treatment with antipsychotic medications. Furthermore, laboratory studies have failed to demonstrate any "beneficial" effects of cannabinoid agonists in individuals with schizophrenia-challenging the cannabis self-medication hypothesis. Emerging evidence suggests that polymorphisms of several genes related to dopamine metabolism (e.g., COMT, DAT1, and AKT1) may moderate the effects of cannabinoid agonists in laboratory studies. Cannabinoid agonists induce dopamine release, although the magnitude of release does not appear to be commensurate to the magnitude and spectrum of their acute psychotomimetic effects. Interactions between the endocannabinoid, gamma-aminobutyric acid, and glutamate systems and their individual and interactive effects on neural oscillations provide a plausible mechanism underlying the psychotomimetic effects of

An international marine-atmospheric {sup 222}Rn measurement intercomparison in Bermuda. Part 1: NIST calibration and methodology for standardized sample additions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colle, R.; Unterweger, M.P.; Hodge, P.A.

1996-01-01

As part of an international {sup 222}Rn measurement intercomparison conducted at Bermuda in October 1991, NIST provided standardized sample additions of known, but undisclosed (blind) {sup 222}Rn concentrations that could be related to US national standards. The standardized sample additions were obtained with a calibrated {sup 226}Ra source and a specially-designed manifold used to obtain well-known dilution factors from simultaneous flow-rate measurements. The additions were introduced over sampling periods of several hours (typically 4 h) into a common streamline on a sampling tower used by the participating laboratories for their measurements. The standardized {sup 222}Rn activity concentrations for the intercomparisonmore » ranged from approximately 2.5 Bq {center_dot} m{sup {minus}3} to 35 Bq {center_dot} m{sup {minus}3} (of which the lower end of this range approached concentration levels for ambient Bermudian air) and had overall uncertainties, approximating a 3 standard deviation uncertainty interval, of about 6% to 13%. This paper describes the calibration and methodology for the standardized sample additions.« less

The Ice Sheet Mass Balance Inter-comparison Exercise

NASA Astrophysics Data System (ADS)

Shepherd, A.; Ivins, E. R.

2015-12-01

Fluctuations in the mass of ice stored in Antarctica and Greenland are of considerable societal importance. The Ice Sheet Mass Balance Inter-Comparison Exercise (IMBIE) is a joint-initiative of ESA and NASA aimed at producing a single estimate of the global sea level contribution to polar ice sheet losses. Within IMBIE, estimates of ice sheet mass balance are developed from a variety of satellite geodetic techniques using a common spatial and temporal reference frame and a common appreciation of the contributions due to external signals. The project brings together the laboratories and space agencies that have been instrumental in developing independent estimates of ice sheet mass balance to date. In its first phase, IMBIE involved 27 science teams, and delivered a first community assessment of ice sheet mass imbalance to replace 40 individual estimates. The project established that (i) there is good agreement between the three main satellite-based techniques for estimating ice sheet mass balance, (ii) combining satellite data sets leads to significant improvement in certainty, (iii) the polar ice sheets contributed 11 ± 4 mm to global sea levels between 1992 and 2012, and (iv) that combined ice losses from Antarctica and Greenland have increased over time, rising from 10% of the global trend in the early 1990's to 30% in the late 2000's. Demand for an updated assessment has grown, and there are now new satellite missions, new geophysical corrections, new techniques, and new teams producing data. The period of overlap between independent satellite techniques has increased from 5 to 12 years, and the full period of satellite data over which an assessment can be performed has increased from 19 to 40 years. It is also clear that multiple satellite techniques are required to confidently separate mass changes associated with snowfall and ice dynamical imbalance - information that is of critical importance for climate modelling. This presentation outlines the approach

Inter-Comparison of CHARM Data and WSR-88D Storm Integrated Rainfall

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Meyer, Paul J.; Guillory, Anthony R.; Stellman, Keith; Limaye, Ashutosh; Arnold, James E. (Technical Monitor)

2002-01-01

A localized precipitation network has been established over a 4000 sq km region of northern Alabama in support of local weather and climate research at the Global Hydrology and Climate Center (GHCC) in Huntsville. This Cooperative Huntsville-Area Rainfall Measurement (CHARM) network is comprised of over 80 volunteers who manually take daily rainfall measurements from 85 sites. The network also incorporates 20 automated gauges that report data at 1-5 minute intervals on a 24 h a day basis. The average spacing of the gauges in the network is about 6 kin, however coverage in some regions benefit from gauges every 1-2 km. The 24 h rainfall totals from the CHARM network have been used to validate Stage III rainfall estimates of daily and storm totals derived from the WSR-88D radars that cover northern Alabama. The Stage III rainfall product is produced by the Lower Mississippi River Forecast Center (LMRFC) in support of their daily forecast operations. The intercomparisons between the local rain gauge and the radar estimates have been useful to understand the accuracy and utility of the Stage III data. Recently, the Stage III and CHARM rainfall measurements have been combined to produce an hourly rainfall dataset at each CHARM observation site. The procedure matches each CHARM site with a time sequence of Stage III radar estimates of precipitation. Hourly stage III rainfall estimates were used to partition the rain gauge values to the time interval over which they occurred. The new hourly rain gauge dataset is validated at selected points where 1-5 minute rainfall measurements have been made. This procedure greatly enhances the utility of the CHARM data for local weather and hydrologic modeling studies. The conference paper will present highlights of the Stage III intercomparison and some examples of the combined radar / rain gauge product demonstrating its accuracy and utility in deriving an hourly rainfall product from the 24 h CHARM totals.

Evaluation and intercomparison of five major dry deposition ...

EPA Pesticide Factsheets

Dry deposition of various pollutants needs to be quantified in air quality monitoring networks as well as in chemical transport models. The inferential method is the most commonly used approach in which the dry deposition velocity (Vd) is empirically parameterized as a function of meteorological and biological conditions and pollutant species’ chemical properties. Earlier model intercomparison studies suggested that existing dry deposition algorithms produce quite different Vd values, e.g., up to a factor of 2 for monthly to annual average values for ozone, and sulfur and nitrogen species (Flechard et al., 2011; Schwede et al., 2011; Wu et al., 2011). To further evaluate model discrepancies using available flux data, this study compared the five dry deposition algorithms commonly used in North America and evaluated the models using five-year Vd(O3) and Vd(SO2) data generated from concentration gradient measurements above a temperate mixed forest in Canada. The five algorithms include: (1) the one used in the Canadian Air and Precipitation Monitoring Network (CAPMoN) and several Canadian air quality models based on Zhang et al. (2003), (2) the one used in the US Clean Air Status and Trends Network (CASTNET) based on Meyers et al. (1998), (3) the one used in the Community Multiscale Air Quality (CMAQ) model described in Pleim and Ran (2011), (4) the Noah land surface model coupled with a photosynthesis-based Gas Exchange Model (Noah-GEM) described in Wu et a

Spatial inter-comparison of Top-down emission inventories in European urban areas

NASA Astrophysics Data System (ADS)

Trombetti, Marco; Thunis, Philippe; Bessagnet, Bertrand; Clappier, Alain; Couvidat, Florian; Guevara, Marc; Kuenen, Jeroen; López-Aparicio, Susana

2018-01-01

This paper presents an inter-comparison of the main Top-down emission inventories currently used for air quality modelling studies at the European level. The comparison is developed for eleven European cities and compares the distribution of emissions of NOx, SO2, VOC and PPM2.5 from the road transport, residential combustion and industry sectors. The analysis shows that substantial differences in terms of total emissions, sectorial emission shares and spatial distribution exist between the datasets. The possible reasons in terms of downscaling approaches and choice of spatial proxies are analysed and recommendations are provided for each inventory in order to work towards the harmonisation of spatial downscaling and proxy calibration, in particular for policy purposes. The proposed methodology may be useful for the development of consistent and harmonised European-wide inventories with the aim of reducing the uncertainties in air quality modelling activities.

Case Studies in Sustainability Used in an Introductory Laboratory Course to Enhance Laboratory Instruction

ERIC Educational Resources Information Center

Luster-Teasley, Stephanie; Hargrove-Leak, Sirena; Gibson, Willietta; Leak, Roland

2017-01-01

This educational research seeks to develop novel laboratory modules by using Case Studies in the Science Teaching method to introduce sustainability and environmental engineering laboratory concepts to 21st century learners. The increased interest in "going green" has led to a surge in the number of engineering students studying…

Field intercomparison of prevailing sonic anemometers

NASA Astrophysics Data System (ADS)

Mauder, Matthias; Zeeman, Matthias J.

2018-01-01

Three-dimensional sonic anemometers are the core component of eddy covariance systems, which are widely used for micrometeorological and ecological research. In order to characterize the measurement uncertainty of these instruments we present and analyse the results from a field intercomparison experiment of six commonly used sonic anemometer models from four major manufacturers. These models include Campbell CSAT3, Gill HS-50 and R3, METEK uSonic-3 Omni, R. M. Young 81000 and 81000RE. The experiment was conducted over a meadow at the TERENO/ICOS site DE-Fen in southern Germany over a period of 16 days in June of 2016 as part of the ScaleX campaign. The measurement height was 3 m for all sensors, which were separated by 9 m from each other, each on its own tripod, in order to limit contamination of the turbulence measurements by adjacent structures as much as possible. Moreover, the high-frequency data from all instruments were treated with the same post-processing algorithm. In this study, we compare the results for various turbulence statistics, which include mean horizontal wind speed, standard deviations of vertical wind velocity and sonic temperature, friction velocity, and the buoyancy flux. Quantitative measures of uncertainty, such as bias and comparability, are derived from these results. We find that biases are generally very small for all sensors and all computed variables, except for the sonic temperature measurements of the two Gill sonic anemometers (HS and R3), confirming a known transducer-temperature dependence of the sonic temperature measurement. The best overall agreement between the different instruments was found for the mean wind speed and the buoyancy flux.

Intercomparison of land-surface parameterizations launched

NASA Astrophysics Data System (ADS)

Henderson-Sellers, A.; Dickinson, R. E.

One of the crucial tasks for climatic and hydrological scientists over the next several years will be validating land surface process parameterizations used in climate models. There is not, necessarily, a unique set of parameters to be used. Different scientists will want to attempt to capture processes through various methods “for example, Avissar and Verstraete, 1990”. Validation of some aspects of the available (and proposed) schemes' performance is clearly required. It would also be valuable to compare the behavior of the existing schemes [for example, Dickinson et al., 1991; Henderson-Sellers, 1992a].The WMO-CAS Working Group on Numerical Experimentation (WGNE) and the Science Panel of the GEWEX Continental-Scale International Project (GCIP) [for example, Chahine, 1992] have agreed to launch the joint WGNE/GCIP Project for Intercomparison of Land-Surface Parameterization Schemes (PILPS). The principal goal of this project is to achieve greater understanding of the capabilities and potential applications of existing and new land-surface schemes in atmospheric models. It is not anticipated that a single “best” scheme will emerge. Rather, the aim is to explore alternative models in ways compatible with their authors' or exploiters' goals and to increase understanding of the characteristics of these models in the scientific community.

The Geoengineering Model Intercomparison Project Phase 6 (GeoMIP6): Simulation design and preliminary results

DOE PAGES

Kravitz, Benjamin S.; Robock, Alan; Tilmes, S.; ...

2015-10-27

We present a suite of new climate model experiment designs for the Geoengineering Model Intercomparison Project (GeoMIP). This set of experiments, named GeoMIP6 (to be consistent with the Coupled Model Intercomparison Project Phase 6), builds on the previous GeoMIP project simulations, and has been expanded to address several further important topics, including key uncertainties in extreme events, the use of geoengineering as part of a portfolio of responses to climate change, and the relatively new idea of cirrus cloud thinning to allow more long wave radiation to escape to space. We discuss experiment designs, as well as the rationale formore » those designs, showing preliminary results from individual models when available. We also introduce a new feature, called the GeoMIP Testbed, which provides a platform for simulations that will be performed with a few models and subsequently assessed to determine whether the proposed experiment designs will be adopted as core (Tier 1) GeoMIP experiments. In conclusion, this is meant to encourage various stakeholders to propose new targeted experiments that address their key open science questions, with the goal of making GeoMIP more relevant to a broader set of communities.« less

The Joint Experiment for Crop Assessment and Monitoring (JECAM): Update on Multisite Inter-comparison Experiments

NASA Astrophysics Data System (ADS)

Jarvis, I.; Gilliams, S. J. B.; Defourny, P.

2016-12-01

Globally there is significant convergence on agricultural monitoring research questions. The focus of interest usually revolves around crop type, crop area estimation and near real time crop condition and yield forecasting. Notwithstanding this convergence, agricultural systems differ significantly throughout the world, reflecting the diversity of ecosystems they are located in. Consequently, a global system of systems for operational monitoring must be based on multiple approaches. Research is required to compare and assess these approaches to identify which are most appropriate for any given location. To this end the Joint Experiments for Crop Assessment and Monitoring (JECAM) was established in 2009 to as a research platform to allow the global agricultural monitoring community to work towards a set of best practices and recommendations for using earth observation data to map, monitor and report on agricultural productivity globally. The JECAM initiative brings together researchers from a large number of globally distributed, well monitored agricultural test sites that cover a range of crop types, cropping systems and climate regimes. The results of JECAM optical inter-comparison research taking place in the Stimulating Innovation for Global Monitoring of Agriculture (SIGMA) project and the Sentinel-2 for Agriculture project will be discussed. The presentation will also highlight upcoming work on a Synthetic Aperture Radar (SAR) inter-comparison study. The outcome of these projects will result in a set of best practices that cover the range of remote sensing monitoring and reporting needs, including satellite data acquisition, pre-processing techniques, information retrieval and ground data validation. These outcomes provide the R&D foundation for GEOGLAM and will help to inform the development of the GEOGLAM system of systems for global agricultural monitoring.

[External quality assessment in clinical biochemistry laboratories: pilot study in 11 laboratories of Lomé (Togo)].

PubMed

Kouassi, Kafui; Fétéké, Lochina; Assignon, Selom; Dorkenoo, Ameyo; Napo-Koura, Gado

2015-01-01

This study aims to evaluate the performance of a few biochemistry analysis and make recommendations to the place of the stakeholders. It is a cross-sectional study conducted between the October 1(st), 2012 and the July 31, 2013 bearing on the results of 5 common examinations of clinical biochemistry, provided by 11 laboratories volunteers opening in the public and private sectors. These laboratories have analysed during the 3 cycles, 2 levels (medium and high) of serum concentration of urea, glucose, creatinine and serum aminotransferases. The performance of laboratories have been determined from the acceptable limits corresponding to the limits of total errors, defined by the French Society of Clinical Biology (SFBC). A system of internal quality control is implemented by all laboratories and 45% of them participated in international programs of external quality assessment (EQA). The rate of acceptable results for the entire study was of 69%. There was a significant difference (p<0.002) between the performance of the group of laboratories engaged in a quality approach and the group with default implementation of the quality approach. Also a significant difference was observed between the laboratories of the central level and those of the peripheral level of our health system (p<0.047). The performance of the results provided by the laboratories remains relatively unsatisfactory. It is important that the Ministry of Health put in place a national program of EQA with mandatory participation.

Standardization of Laboratory Methods for the PERCH Study

PubMed Central

Karron, Ruth A.; Morpeth, Susan C.; Bhat, Niranjan; Levine, Orin S.; Baggett, Henry C.; Brooks, W. Abdullah; Feikin, Daniel R.; Hammitt, Laura L.; Howie, Stephen R. C.; Knoll, Maria Deloria; Kotloff, Karen L.; Madhi, Shabir A.; Scott, J. Anthony G.; Thea, Donald M.; Adrian, Peter V.; Ahmed, Dilruba; Alam, Muntasir; Anderson, Trevor P.; Antonio, Martin; Baillie, Vicky L.; Dione, Michel; Endtz, Hubert P.; Gitahi, Caroline; Karani, Angela; Kwenda, Geoffrey; Maiga, Abdoul Aziz; McClellan, Jessica; Mitchell, Joanne L.; Morailane, Palesa; Mugo, Daisy; Mwaba, John; Mwansa, James; Mwarumba, Salim; Nyongesa, Sammy; Panchalingam, Sandra; Rahman, Mustafizur; Sawatwong, Pongpun; Tamboura, Boubou; Toure, Aliou; Whistler, Toni; O’Brien, Katherine L.; Murdoch, David R.

2017-01-01

Abstract The Pneumonia Etiology Research for Child Health study was conducted across 7 diverse research sites and relied on standardized clinical and laboratory methods for the accurate and meaningful interpretation of pneumonia etiology data. Blood, respiratory specimens, and urine were collected from children aged 1–59 months hospitalized with severe or very severe pneumonia and community controls of the same age without severe pneumonia and were tested with an extensive array of laboratory diagnostic tests. A standardized testing algorithm and standard operating procedures were applied across all study sites. Site laboratories received uniform training, equipment, and reagents for core testing methods. Standardization was further assured by routine teleconferences, in-person meetings, site monitoring visits, and internal and external quality assurance testing. Targeted confirmatory testing and testing by specialized assays were done at a central reference laboratory. PMID:28575358

The ASSET intercomparison of stratosphere and lower mesosphere humidity analyses

NASA Astrophysics Data System (ADS)

Thornton, H. E.; Jackson, D. R.; Bekki, S.; Bormann, N.; Errera, Q.; Geer, A. J.; Lahoz, W. A.; Rharmili, S.

2008-07-01

This paper presents results from the first detailed intercomparison of stratosphere-lower mesosphere water vapour analyses; it builds on earlier results from the "Assimilation of ENVISAT Data" (ASSET) project. With the availability of high resolution, good quality Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) water vapour profiles, the ability of four different atmospheric models to assimilate these data is tested. MIPAS data have been assimilated over September 2003 into the models of the European Centre for Medium Range Weather Forecasts (ECMWF), the Belgian Institute for Space and Aeronomy (BIRA-IASB), the French Service d'Aéronomie (SA-IPSL) and the UK Met Office. The resultant middle atmosphere humidity analyses are compared against independent satellite data from the Halogen Occultation Experiment (HALOE), the Polar Ozone and Aerosol Measurement (POAM III) and the Stratospheric Aerosol and Gas Experiment (SAGE II). The MIPAS water vapour profiles are generally well assimilated in the ECMWF, BIRA-IASB and SA systems, producing stratosphere-mesosphere water vapour fields where the main features compare favourably with the independent observations. However, the models are less capable of assimilating the MIPAS data where water vapour values are locally extreme or in regions of strong humidity gradients, such as the Southern Hemisphere lower stratosphere polar vortex. Differences in the analyses can be attributed to the choice of humidity control variable, how the background error covariance matrix is generated, the model resolution and its complexity, the degree of quality control of the observations and the use of observations near the model boundaries. Due to the poor performance of the Met Office analyses the results are not included in the intercomparison, but are discussed separately. The Met Office results highlight the pitfalls in humidity assimilation, and provide lessons that should be learnt by developers of stratospheric humidity

[Quality Management and Quality Specifications of Laboratory Tests in Clinical Studies--Challenges in Pre-Analytical Processes in Clinical Laboratories].

PubMed

Ishibashi, Midori

2015-01-01

The cost, speed, and quality are the three important factors recently indicated by the Ministry of Health, Labour and Welfare (MHLW) for the purpose of accelerating clinical studies. Based on this background, the importance of laboratory tests is increasing, especially in the evaluation of clinical study participants' entry and safety, and drug efficacy. To assure the quality of laboratory tests, providing high-quality laboratory tests is mandatory. For providing adequate quality assurance in laboratory tests, quality control in the three fields of pre-analytical, analytical, and post-analytical processes is extremely important. There are, however, no detailed written requirements concerning specimen collection, handling, preparation, storage, and shipping. Most laboratory tests for clinical studies are performed onsite in a local laboratory; however, a part of laboratory tests is done in offsite central laboratories after specimen shipping. As factors affecting laboratory tests, individual and inter-individual variations are well-known. Besides these factors, standardizing the factors of specimen collection, handling, preparation, storage, and shipping, may improve and maintain the high quality of clinical studies in general. Furthermore, the analytical method, units, and reference interval are also important factors. It is concluded that, to overcome the problems derived from pre-analytical processes, it is necessary to standardize specimen handling in a broad sense.

An intercomparison of the thermal offset for different pyranometers

NASA Astrophysics Data System (ADS)

Sanchez, G.; Cancillo, M. L.; Serrano, A.

2016-07-01

An unprecedented intensive intercomparison campaign focused on the experimental measurement of the thermal offset of pyranometers has been conducted at Badajoz (Spain) with the participation of three main manufacturers. The purpose of this study is to compare the thermal offset of six commercially available pyranometers, being some of them widely used and others recently commercialized. In this campaign, the capping methodology has been used to experimentally measure the daytime thermal offset of the pyranometers. Thus, a short but intense campaign has been conducted in two selected summer days under clear-sky conditions, covering a large range of solar zenith angle, irradiance, and temperature. Along the campaign, a total of 305 capping events have been performed, 61 for each pyranometer. The daytime thermal offset obtained for different pyranometers ranges between 0 and -16.8 W/m2 depending on the environmental conditions, being sometimes notably higher than values estimated indoors by manufacturers. The thermal offset absolute value of all instruments shows a diurnal cycle, increasing from sunrise to central hours of the day and decreasing from midafternoon to sunset. The analysis demonstrates that thermal offset is notably higher and more variable during daytime than during nighttime, requiring specific daytime measurements. Main results emphasize the key role played by wind speed in modulating the thermal offset.

Intercomparison of global, ultraviolet B and A radiation measurements in the Dead Sea region (Ein Bokek) and Beer Sheva.

PubMed

Kushelevsky, A P; Kudish, A I

1996-07-01

Thousands of patients suffering from psoriasis have been treated successfully in the Dead Sea area by climatological methods, without medication. This high rate of success, measured in terms of partial to complete plaque clearance and reported to exceed 85% after 3-4 weeks of treatment, has been assumed to be associated with a unique ultraviolet (UV) radiation environment present in the Dead Sea region. In order to broaden our knowledge of the UV radiation environment at the Dead Sea, continuous monitoring of UV (both B and A) and global radiation has recently been initiated at two sites--Ein Bokek (located in the vicinity of the Dead Sea 375 m below mean sea level) and Beer Sheva (315 m above mean sea level)--to facilitate an intercomparison of their respective radiation intensities. The results of the first year of a detailed study of the global, UVB and UVA radiation intensities measured at both sites are summarized and reported in terms of the monthly average daily, average midday (11:00-13:00) and the corresponding maximum values. The radiation data for clear days (based upon the absolute magnitude of the global radiation) were also analyzed to perform an intercomparison between Ein Bokek and Beer Sheva for a winter month and a summer month for which all three types of radiation data were available at both sites.

Airborne Polarimeter Intercomparison for the NASA Aerosols-Clouds-Ecosystems (ACE) Mission

NASA Technical Reports Server (NTRS)

Knobelspiesse, Kirk; Redemann, Jens

2014-01-01

The Aerosols-Clouds-Ecosystems (ACE) mission, recommended by the National Research Council's Decadal Survey, calls for a multi-angle, multi-spectral polarimeter devoted to observations of atmospheric aerosols and clouds. In preparation for ACE, NASA funds the deployment of airborne polarimeters, including the Airborne Multi-angle SpectroPolarimeter Imager (AirMSPI), the Passive Aerosol and Cloud Suite (PACS) and the Research Scanning Polarimeter (RSP). These instruments have been operated together on NASA's ER-2 high altitude aircraft as part of field campaigns such as the POlarimeter DEfinition EXperiment (PODEX) (California, early 2013) and Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS, California and Texas, summer 2013). Our role in these efforts has been to serve as an assessment team performing level 1 (calibrated radiance, polarization) and level 2 (retrieved geophysical parameter) instrument intercomparisons, and to promote unified and generalized calibration, uncertainty assessment and retrieval techniques. We will present our progress in this endeavor thus far and describe upcoming research in 2015.

Ozone profile intercomparison based on simultaneous observations between 20 and 40 km

NASA Technical Reports Server (NTRS)

Aimedieu, P.; Krueger, A. J.; Robbins, D. E.; Simon, P. C.

1983-01-01

The vertical distribution of stratospheric ozone has been simultaneously measured by means of five different instruments carried on the same balloon payload. The launches were performed from Gap during the intercomparison campaign conducted in June 1981 in southern France. Data obtained between altitudes of 20 and 40 km are compared and discussed. Vertical profiles deduced from Electrochemical Concentration Cell sondes launched from the same location by small balloons and from short Umkehr measurements made at Mt Chiran (France) are also included in this comparison. Systematic differences of the order of 20 percent between ozone profiles deduced from solar u.v. absorption and in situ techniques are found.

Intercomparison of methods for coincidence summing corrections in gamma-ray spectrometry--part II (volume sources).

PubMed

Lépy, M-C; Altzitzoglou, T; Anagnostakis, M J; Capogni, M; Ceccatelli, A; De Felice, P; Djurasevic, M; Dryak, P; Fazio, A; Ferreux, L; Giampaoli, A; Han, J B; Hurtado, S; Kandic, A; Kanisch, G; Karfopoulos, K L; Klemola, S; Kovar, P; Laubenstein, M; Lee, J H; Lee, J M; Lee, K B; Pierre, S; Carvalhal, G; Sima, O; Tao, Chau Van; Thanh, Tran Thien; Vidmar, T; Vukanac, I; Yang, M J

2012-09-01

The second part of an intercomparison of the coincidence summing correction methods is presented. This exercise concerned three volume sources, filled with liquid radioactive solution. The same experimental spectra, decay scheme and photon emission intensities were used by all the participants. The results were expressed as coincidence summing corrective factors for several energies of (152)Eu and (134)Cs, and different source-to-detector distances. They are presented and discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

TLD postal dose intercomparison for megavoltage units in Poland.

PubMed

Izewska, J; Gajewski, R; Gwiazdowska, B; Kania, M; Rostkowska, J

1995-08-01

The aim of the TLD pilot study was to investigate and to reduce the uncertainties involved in the measurements of absorbed dose and to improve the consistency in dose determination in the regional radiotherapy centres in Poland. The intercomparison was organized by the SSDL. It covered absorbed dose measurements under reference conditions for Co-60, high energy X-rays and electron beams. LiF powder type MT-N was used for the irradiations and read with the Harshaw TLD reader model 2000B/2000C. The TLD system was set up and an analysis of the factors influencing the accuracy of absorbed dose measurements with TL-detectors was performed to evaluate and minimize the measurement uncertainty. A fading not exceeding 2% in 12 weeks was found. The relative energy correction factor did not exceed 3% for X-rays in the range 4-15 MV, and 4% for electron beams between 6 and 20 MeV. A total of 34 beams was checked. Deviation of +/- 3.5% stated and evaluated dose was considered acceptable for photons and +/- 5% for electron beams. The results for Co-60, high energy X-rays and electron beams showed that there were two, three and no centres, respectively, beyond acceptance levels. The sources of errors for all deviations out of this range were thoroughly investigated, discussed and corrected, however two deviations remained unexplained. The pilot study resulted in an improvement of the accuracy and consistency of dosimetry in Poland.

The Cloud Feedback Model Intercomparison Project Observational Simulator Package: Version 2

NASA Astrophysics Data System (ADS)

Swales, Dustin J.; Pincus, Robert; Bodas-Salcedo, Alejandro

2018-01-01

The Cloud Feedback Model Intercomparison Project Observational Simulator Package (COSP) gathers together a collection of observation proxies or satellite simulators that translate model-simulated cloud properties to synthetic observations as would be obtained by a range of satellite observing systems. This paper introduces COSP2, an evolution focusing on more explicit and consistent separation between host model, coupling infrastructure, and individual observing proxies. Revisions also enhance flexibility by allowing for model-specific representation of sub-grid-scale cloudiness, provide greater clarity by clearly separating tasks, support greater use of shared code and data including shared inputs across simulators, and follow more uniform software standards to simplify implementation across a wide range of platforms. The complete package including a testing suite is freely available.

Intercomparison of general circulation models for hot extrasolar planets

NASA Astrophysics Data System (ADS)

Polichtchouk, I.; Cho, J. Y.-K.; Watkins, C.; Thrastarson, H. Th.; Umurhan, O. M.; de la Torre Juárez, M.

2014-02-01

We compare five general circulation models (GCMs) which have been recently used to study hot extrasolar planet atmospheres (BOB, CAM, IGCM, MITgcm, and PEQMOD), under three test cases useful for assessing model convergence and accuracy. Such a broad, detailed intercomparison has not been performed thus far for extrasolar planets study. The models considered all solve the traditional primitive equations, but employ different numerical algorithms or grids (e.g., pseudospectral and finite volume, with the latter separately in longitude-latitude and ‘cubed-sphere’ grids). The test cases are chosen to cleanly address specific aspects of the behaviors typically reported in hot extrasolar planet simulations: (1) steady-state, (2) nonlinearly evolving baroclinic wave, and (3) response to fast timescale thermal relaxation. When initialized with a steady jet, all models maintain the steadiness, as they should-except MITgcm in cubed-sphere grid. A very good agreement is obtained for a baroclinic wave evolving from an initial instability in pseudospectral models (only). However, exact numerical convergence is still not achieved across the pseudospectral models: amplitudes and phases are observably different. When subject to a typical ‘hot-Jupiter’-like forcing, all five models show quantitatively different behavior-although qualitatively similar, time-variable, quadrupole-dominated flows are produced. Hence, as have been advocated in several past studies, specific quantitative predictions (such as the location of large vortices and hot regions) by GCMs should be viewed with caution. Overall, in the tests considered here, pseudospectral models in pressure coordinate (PEBOB and PEQMOD) perform the best and MITgcm in cubed-sphere grid performs the worst.

Intercomparison of an Aerosol Chemical Speciation Monitor (ACSM) with ambient fine aerosol measurements in downtown Atlanta, Georgia

NASA Astrophysics Data System (ADS)

Budisulistiorini, S. H.; Canagaratna, M. R.; Croteau, P. L.; Baumann, K.; Edgerton, E. S.; Kollman, M. S.; Ng, N. L.; Verma, V.; Shaw, S. L.; Knipping, E. M.; Worsnop, D. R.; Jayne, J. T.; Weber, R. J.; Surratt, J. D.

2014-07-01

Currently, there are a limited number of field studies that evaluate the long-term performance of the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) against established monitoring networks. In this study, we present seasonal intercomparisons of the ACSM with collocated fine aerosol (PM2.5) measurements at the Southeastern Aerosol Research and Characterization (SEARCH) Jefferson Street (JST) site near downtown Atlanta, GA, during 2011-2012. Intercomparison of two collocated ACSMs resulted in strong correlations (r2 > 0.8) for all chemical species, except chloride (r2 = 0.21) indicating that ACSM instruments are capable of stable and reproducible operation. In general, speciated ACSM mass concentrations correlate well (r2 > 0.7) with the filter-adjusted continuous measurements from JST, although the correlation for nitrate is weaker (r2 = 0.55) in summer. Correlations of the ACSM NR-PM1 (non-refractory particulate matter with aerodynamic diameter less than or equal to 1 μm) plus elemental carbon (EC) with tapered element oscillating microbalance (TEOM) PM2.5 and Federal Reference Method (FRM) PM1 mass are strong with r2 > 0.7 and r2 > 0.8, respectively. Discrepancies might be attributed to evaporative losses of semi-volatile species from the filter measurements used to adjust the collocated continuous measurements. This suggests that adjusting the ambient aerosol continuous measurements with results from filter analysis introduced additional bias to the measurements. We also recommend to calibrate the ambient aerosol monitoring instruments using aerosol standards rather than gas-phase standards. The fitting approach for ACSM relative ionization for sulfate was shown to improve the comparisons between ACSM and collocated measurements in the absence of calibrated values, suggesting the importance of adding sulfate calibration into the ACSM calibration routine.

LABORATORY SCALE STEAM INJECTION TREATABILITY STUDIES

EPA Science Inventory

Laboratory scale steam injection treatability studies were first developed at The University of California-Berkeley. A comparable testing facility has been developed at USEPA's Robert S. Kerr Environmental Research Center. Experience has already shown that many volatile organic...

Intercomparison of an Aerosol Chemical Speciation Monitor (ACSM) with ambient fine aerosol measurements in Downtown Atlanta, Georgia

NASA Astrophysics Data System (ADS)

Budisulistiorini, S. H.; Canagaratna, M. R.; Croteau, P. L.; Baumann, K.; Edgerton, E. S.; Kollman, M. S.; Ng, N. L.; Verma, V.; Shaw, S. L.; Knipping, E. M.; Worsnop, D. R.; Jayne, J. T.; Weber, R. J.; Surratt, J. D.

2013-12-01

The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was recently developed to provide long-term real-time continuous measurements of ambient non-refractory (i.e., organic, sulfate, ammonium, nitrate, and chloride) submicron particulate matter (NR-PM1). Currently, there are a limited number of field studies that evaluate the long-term performance of the ACSM against established monitoring networks. In this study, we present seasonal intercomparisons of the ACSM with collocated fine aerosol (PM2.5) measurements at the Southeastern Aerosol Research and Characterization (SEARCH) Jefferson Street (JST) site near downtown Atlanta, GA, during 2011-2012. The collocated measurements included a second ACSM, continuous and integrated sulfate, nitrate, and ammonium measurements, as well as a semi-continuous Sunset organic carbon/elemental carbon (OC/EC) analyzer, continuous tapered element oscillating microbalance (TEOM), 24 h integrated Federal Reference Method (FRM) filters, and continuous scanning electrical mobility system-mixing condensation particle counter (SEMS-MCPC). Intercomparison of the two collocated ACSMs resulted in strong correlations (r2 > 0.8) for all chemical species, except chloride (r2 = 0.21); mass concentration for all chemical species agreed within ±27%, indicating that ACSM instruments are capable of stable and reproducible operation. Chemical constituents measured by the ACSM are also compared with those obtained from the continuous measurements from JST. Since the continuous measurement concentrations are adjusted to match the integrated filter measurements, these comparisons reflect the combined uncertainties of the ACSM, continuous, and filter measurements. In general, speciated ACSM mass concentrations correlate well (r2 > 0.7) with the continuous measurements from JST, although the correlation for nitrate is weaker (r2 = 0.55) in summer. Differences between ACSM mass concentrations and the filter-adjusted JST continuous data are 5-27%, 4

A Monte Carlo Simulation of the in vivo measurement of lung activity in the Lawrence Livermore National Laboratory torso phantom.

PubMed

Acha, Robert; Brey, Richard; Capello, Kevin

2013-02-01

A torso phantom was developed by the Lawrence Livermore National Laboratory (LLNL) that serves as a standard for intercomparison and intercalibration of detector systems used to measure low-energy photons from radionuclides, such as americium deposited in the lungs. DICOM images of the second-generation Human Monitoring Laboratory-Lawrence Livermore National Laboratory (HML-LLNL) torso phantom were segmented and converted into three-dimensional (3D) voxel phantoms to simulate the response of high purity germanium (HPGe) detector systems, as found in the HML new lung counter using a Monte Carlo technique. The photon energies of interest in this study were 17.5, 26.4, 45.4, 59.5, 122, 244, and 344 keV. The detection efficiencies at these photon energies were predicted for different chest wall thicknesses (1.49 to 6.35 cm) and compared to measured values obtained with lungs containing (241)Am (34.8 kBq) and (152)Eu (10.4 kBq). It was observed that no statistically significant differences exist at the 95% confidence level between the mean values of simulated and measured detection efficiencies. Comparisons between the simulated and measured detection efficiencies reveal a variation of 20% at 17.5 keV and 1% at 59.5 keV. It was found that small changes in the formulation of the tissue substitute material caused no significant change in the outcome of Monte Carlo simulations.

[Study of quality of a branch laboratory--an opinion of a laboratory manager].

PubMed

Yazawa, Naoyuki

2006-11-01

At the stage of establishing a branch laboratory, quality evaluation is extremely difficult. Even the results of a control survey by the headquarters of the branch laboratory are unhelpful. For a clinical laboratory, the most important function is to provide reliable data all the time, and to maintain the reliability of clinical doctors with informed responses. We mostly refer to control surveys and daily quality control data to evaluate a clinical laboratory, but we rarely check its fundamental abilities, such as planning events, preserving statistical data about the standard range, using the right method for quality control and others. This is generally disregarded and it is taken for granted that they will be correct the first time. From my six years of experience working with X's branch laboratory, I realized that there might be some relation between the quality of a branch laboratory and the fundamental abilities of the company itself. I would never argue that all branch laboratories are ineffective, but they should be conscious of fundamental activities. The referring laboratory, not the referral laboratory, should be responsible for ensuring that the referral laboratory's examination results and findings are correct.

Desert Dust Satellite Retrieval Intercomparison

NASA Technical Reports Server (NTRS)

Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.;

C4MIP - The Coupled Climate-Carbon Cycle Model Intercomparison Project: experimental protocol for CMIP6

NASA Astrophysics Data System (ADS)

Jones, Chris D.; Arora, Vivek; Friedlingstein, Pierre; Bopp, Laurent; Brovkin, Victor; Dunne, John; Graven, Heather; Hoffman, Forrest; Ilyina, Tatiana; John, Jasmin G.; Jung, Martin; Kawamiya, Michio; Koven, Charlie; Pongratz, Julia; Raddatz, Thomas; Randerson, James T.; Zaehle, Sönke

2016-08-01

Coordinated experimental design and implementation has become a cornerstone of global climate modelling. Model Intercomparison Projects (MIPs) enable systematic and robust analysis of results across many models, by reducing the influence of ad hoc differences in model set-up or experimental boundary conditions. As it enters its 6th phase, the Coupled Model Intercomparison Project (CMIP6) has grown significantly in scope with the design and documentation of individual simulations delegated to individual climate science communities. The Coupled Climate-Carbon Cycle Model Intercomparison Project (C4MIP) takes responsibility for design, documentation, and analysis of carbon cycle feedbacks and interactions in climate simulations. These feedbacks are potentially large and play a leading-order contribution in determining the atmospheric composition in response to human emissions of CO2 and in the setting of emissions targets to stabilize climate or avoid dangerous climate change. For over a decade, C4MIP has coordinated coupled climate-carbon cycle simulations, and in this paper we describe the C4MIP simulations that will be formally part of CMIP6. While the climate-carbon cycle community has created this experimental design, the simulations also fit within the wider CMIP activity, conform to some common standards including documentation and diagnostic requests, and are designed to complement the CMIP core experiments known as the Diagnostic, Evaluation and Characterization of Klima (DECK). C4MIP has three key strands of scientific motivation and the requested simulations are designed to satisfy their needs: (1) pre-industrial and historical simulations (formally part of the common set of CMIP6 experiments) to enable model evaluation, (2) idealized coupled and partially coupled simulations with 1 % per year increases in CO2 to enable diagnosis of feedback strength and its components, (3) future scenario simulations to project how the Earth system will respond to

Laboratory studies in ultraviolet solar physics

NASA Technical Reports Server (NTRS)

Parkinson, W. H.; Kohl, J. L.; Gardner, L. D.; Raymond, J. C.; Smith, P. L.

1991-01-01

The research activity comprised the measurement of basic atomic processes and parameters which relate directly to the interpretation of solar ultraviolet observations and to the development of comprehensive models of the component structures of the solar atmosphere. The research was specifically directed towards providing the relevant atomic data needed to perform and to improve solar diagnostic techniques which probe active and quiet portions of the solar chromosphere, the transition zone, the inner corona, and the solar wind acceleration regions of the extended corona. The accuracy with which the physical conditions in these structures can be determined depends directly on the accuracy and completeness of the atomic and molecular data. These laboratory data are used to support the analysis programs of past and current solar observations (e.g., the Orbiting solar Observatories, the Solar Maximum Mission, the Skylab Apollo Telescope Mount, and the Naval Research Laboratory's rocket-borne High Resolution Telescope and Spectrograph). In addition, we attempted to anticipate the needs of future space-borne solar studies such as from the joint ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft. Our laboratory activities stressed two categories of study: (1) the measurement of absolute rate coefficients for dielectronic recombination and electron impact excitation; and (2) the measurement of atomic transition probabilities for solar density diagnostics. A brief summary of the research activity is provided.

An inter-comparison of PM10 source apportionment using PCA and PMF receptor models in three European sites.

PubMed

Cesari, Daniela; Amato, F; Pandolfi, M; Alastuey, A; Querol, X; Contini, D

2016-08-01

Source apportionment of aerosol is an important approach to investigate aerosol formation and transformation processes as well as to assess appropriate mitigation strategies and to investigate causes of non-compliance with air quality standards (Directive 2008/50/CE). Receptor models (RMs) based on chemical composition of aerosol measured at specific sites are a useful, and widely used, tool to perform source apportionment. However, an analysis of available studies in the scientific literature reveals heterogeneities in the approaches used, in terms of "working variables" such as the number of samples in the dataset and the number of chemical species used as well as in the modeling tools used. In this work, an inter-comparison of PM10 source apportionment results obtained at three European measurement sites is presented, using two receptor models: principal component analysis coupled with multi-linear regression analysis (PCA-MLRA) and positive matrix factorization (PMF). The inter-comparison focuses on source identification, quantification of source contribution to PM10, robustness of the results, and how these are influenced by the number of chemical species available in the datasets. Results show very similar component/factor profiles identified by PCA and PMF, with some discrepancies in the number of factors. The PMF model appears to be more suitable to separate secondary sulfate and secondary nitrate with respect to PCA at least in the datasets analyzed. Further, some difficulties have been observed with PCA in separating industrial and heavy oil combustion contributions. Commonly at all sites, the crustal contributions found with PCA were larger than those found with PMF, and the secondary inorganic aerosol contributions found by PCA were lower than those found by PMF. Site-dependent differences were also observed for traffic and marine contributions. The inter-comparison of source apportionment performed on complete datasets (using the full range of

The ASSET intercomparison of stratosphere and lower mesosphere humidity analyses

NASA Astrophysics Data System (ADS)

Thornton, H. E.; Jackson, D. R.; Bekki, S.; Bormann, N.; Errera, Q.; Geer, A. J.; Lahoz, W. A.; Rharmili, S.

2009-02-01

This paper presents results from the first detailed intercomparison of stratosphere-lower mesosphere water vapour analyses; it builds on earlier results from the EU funded framework V "Assimilation of ENVISAT Data" (ASSET) project. Stratospheric water vapour plays an important role in many key atmospheric processes and therefore an improved understanding of its daily variability is desirable. With the availability of high resolution, good quality Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) water vapour profiles, the ability of four different atmospheric models to assimilate these data is tested. MIPAS data have been assimilated over September 2003 into the models of the European Centre for Medium Range Weather Forecasts (ECMWF), the Belgian Institute for Space and Aeronomy (BIRA-IASB), the French Service d'Aéronomie (SA-IPSL) and the UK Met Office. The resultant middle atmosphere humidity analyses are compared against independent satellite data from the Halogen Occultation Experiment (HALOE), the Polar Ozone and Aerosol Measurement (POAM III) and the Stratospheric Aerosol and Gas Experiment (SAGE II). The MIPAS water vapour profiles are generally well assimilated in the ECMWF, BIRA-IASB and SA systems, producing stratosphere-mesosphere water vapour fields where the main features compare favourably with the independent observations. However, the models are less capable of assimilating the MIPAS data where water vapour values are locally extreme or in regions of strong humidity gradients, such as the southern hemisphere lower stratosphere polar vortex. Differences in the analyses can be attributed to the choice of humidity control variable, how the background error covariance matrix is generated, the model resolution and its complexity, the degree of quality control of the observations and the use of observations near the model boundaries. Due to the poor performance of the Met Office analyses the results are not included in the intercomparison

The Agricultural Model Intercomparison and Improvement Project: Phase I Activities by a Global Community of Science. Chapter 1

NASA Technical Reports Server (NTRS)

Rosenzweig, Cynthia E.; Jones, James W.; Hatfield, Jerry L.; Antle, John M.; Ruane, Alexander C.; Mutter, Carolyn Z.

2015-01-01

The Agricultural Model Intercomparison and Improvement Project (AgMIP) was founded in 2010. Its mission is to improve substantially the characterization of world food security as affected by climate variability and change, and to enhance adaptation capacity in both developing and developed countries. The objectives of AgMIP are to: Incorporate state-of-the-art climate, crop/livestock, and agricultural economic model improvements into coordinated multi-model regional and global assessments of future climate impacts and adaptation and other key aspects of the food system. Utilize multiple models, scenarios, locations, crops/livestock, and participants to explore uncertainty and the impact of data and methodological choices. Collaborate with regional experts in agronomy, animal sciences, economics, and climate to build a strong basis for model applications, addressing key climate related questions and sustainable intensification farming systems. Improve scientific and adaptive capacity in modeling for major agricultural regions in the developing and developed world, with a focus on vulnerable regions. Improve agricultural data and enhance data-sharing based on their intercomparison and evaluation using best scientific practices. Develop modeling frameworks to identify and evaluate promising adaptation technologies and policies and to prioritize strategies.

Data Quality Assessment of In Situ and Altimeter Observations Through Two-Way Intercomparison Methods

NASA Astrophysics Data System (ADS)

Guinehut, Stephanie; Valladeau, Guillaume; Legeais, Jean-Francois; Rio, Marie-Helene; Ablain, Michael; Larnicol, Gilles

2013-09-01

This proceeding presents an overview of the two-way inter-comparison activities performed at CLS for both space and in situ observation agencies and why this activity is a required step to obtain accurate and homogenous data sets that can then be used together for climate studies or in assimilation/validation tools. We first describe the work performed in the frame of the SALP program to assess the stability of altimeter missions through SSH comparisons with tide gauges (GLOSS/CLIVAR network). Then, we show how the SSH comparison between the Argo array and altimeter time series allows the detection of drifts or jumps in altimeter (SALP program) but also for some Argo floats (Ifremer/Coriolis center). Lastly, we describe how the combine use of altimeter and wind observations helps the detection of drogue loss of surface drifting buoys (GDP network) and allow the computation of a correction term for wind slippage.

Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

NASA Astrophysics Data System (ADS)

Hak, C.; Pundt, I.; Trick, S.; Kern, C.; Platt, U.; Dommen, J.; Ordóñez, C.; Prévôt, A. S. H.; Junkermann, W.; Astorga-Lloréns, C.; Larsen, B. R.; Mellqvist, J.; Strandberg, A.; Yu, Y.; Galle, B.; Kleffmann, J.; Lörzer, J. C.; Braathen, G. O.; Volkamer, R.

2005-11-01

Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS), Fourier Transform Infra Red (FTIR) interferometry, the fluorimetric Hantzsch reaction technique (five instruments) and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine). White type multi-reflection systems were employed for the optical techniques in order to avoid spatial CH2O gradients and ensure the sampling of nearly the same air mass by all instruments. Between 23 and 31 July 2002, up to 13 ppbv of CH2O were observed. The concentrations lay well above the detection limits of all instruments. The formaldehyde concentrations determined with DOAS, FTIR and the Hantzsch instruments were found to agree within ±11%, with the exception of one Hantzsch instrument, which gave systematically higher values. The two hour integrated samples by DNPH yielded up to 25% lower concentrations than the data of the continuously measuring instruments averaged over the same time period. The consistency between the DOAS and the Hantzsch method was better than during previous intercomparisons in ambient air with slopes of the regression line not significantly differing from one. The differences between the individual Hantzsch instruments could be attributed in part to the calibration standards used. Possible systematic errors of the methods are discussed.

Intercomparison of four different in-situ techniques for ambient formaldehyde measurements in urban air

NASA Astrophysics Data System (ADS)

Hak, C.; Pundt, I.; Kern, C.; Platt, U.; Dommen, J.; Ordóñez, C.; Prévôt, A. S. H.; Junkermann, W.; Astorga-Lloréns, C.; Larsen, B. R.; Mellqvist, J.; Strandberg, A.; Yu, Y.; Galle, B.; Kleffmann, J.; Lörzer, J. C.; Braathen, G. O.; Volkamer, R.

2005-05-01

Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Optical Absorption Spectroscopy (DOAS), Fourier Transform Infra Red (FTIR) interferometry, the fluorimetric Hantzsch reaction technique (five instruments) and a chromatographic technique employing C18-DNPH-cartridges (2,4-dinitrophenylhydrazine). White type multi-reflection systems were employed for the optical techniques in order to avoid spatial CH2O gradients and ensure the sampling of nearly the same air mass by all instruments. Between 23 and 31 July 2002, up to 13 ppbv of CH2O were observed. The concentrations lay well above the detection limits of all instruments. The formaldehyde concentrations determined with DOAS, FTIR and the Hantzsch instruments were found to agree within ±11%, with the exception of one Hantzsch instrument, which gave systematically higher values. The two hour integrated samples by DNPH yielded up to 25% lower concentrations than the data of the continuously measuring instruments averaged over the same time period. The consistency between the DOAS and the Hantzsch method was better than during previous intercomparisons in ambient air with slopes of the regression line not significantly differing from one. The differences between the individual Hantzsch instruments could be attributed in part to the calibration standards used. Possible systematic errors of the methods are discussed.

The Essential Role for Laboratory Studies in Atmospheric Chemistry.

PubMed

Burkholder, James B; Abbatt, Jonathan P D; Barnes, Ian; Roberts, James M; Melamed, Megan L; Ammann, Markus; Bertram, Allan K; Cappa, Christopher D; Carlton, Annmarie G; Carpenter, Lucy J; Crowley, John N; Dubowski, Yael; George, Christian; Heard, Dwayne E; Herrmann, Hartmut; Keutsch, Frank N; Kroll, Jesse H; McNeill, V Faye; Ng, Nga Lee; Nizkorodov, Sergey A; Orlando, John J; Percival, Carl J; Picquet-Varrault, Bénédicte; Rudich, Yinon; Seakins, Paul W; Surratt, Jason D; Tanimoto, Hiroshi; Thornton, Joel A; Tong, Zhu; Tyndall, Geoffrey S; Wahner, Andreas; Weschler, Charles J; Wilson, Kevin R; Ziemann, Paul J

2017-03-07

Laboratory studies of atmospheric chemistry characterize the nature of atmospherically relevant processes down to the molecular level, providing fundamental information used to assess how human activities drive environmental phenomena such as climate change, urban air pollution, ecosystem health, indoor air quality, and stratospheric ozone depletion. Laboratory studies have a central role in addressing the incomplete fundamental knowledge of atmospheric chemistry. This article highlights the evolving science needs for this community and emphasizes how our knowledge is far from complete, hindering our ability to predict the future state of our atmosphere and to respond to emerging global environmental change issues. Laboratory studies provide rich opportunities to expand our understanding of the atmosphere via collaborative research with the modeling and field measurement communities, and with neighboring disciplines.

A large-scale intercomparison of stratospheric vertical distributions of NO2 and BrO retrieved from the SCIAMACHY limb measurements and ground-based twilight observations

NASA Astrophysics Data System (ADS)

Rozanov, Alexei; Hendrick, Francois; Lotz, Wolfhardt; van Roozendael, Michel; Bovensmann, Heinrich; Burrows, John P.

This study is devoted to the intercomparison of NO2 and BrO vertical profiles obtained from the satellite and ground-based measurements. Although, the ground-based observations are performed only at selected locations, they have a great potential to be used for the validation of satellite measurements since continuous long-term measurement series performed with the same instruments are available. Thus, long-term trends in the observed species can be analyzed and intercompared. Previous intercomparisons of the vertical distributions of NO2 and BrO retrieved from SCIAMACHY limb measurements at the University of Bremen and obtained at IASB-BIRA by applying a profiling technique to ground-based zenith-sky DOAS observations have shown a good agreement between the results of completely different measurement techniques. However, only a relatively short time period of one year was analyzed so far which do not allow investigating seasonal variations and trends. Furthermore, some minor discrepancies are still to be analyzed. In the current study, several years datasets obtained at Observatoire de Haute-Provence (OHP) in France and in Harestua in Norway will be compared to the retrievals of SCIAMACHY limb measurements. Seasonal and annual variations will be analyzed and possible reasons for the remaining discrepancies will be discussed.

Innovative methodology for intercomparison of radionuclide calibrators using short half-life in situ prepared radioactive sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira, P. A.; Santos, J. A. M., E-mail: joao.santos@ipoporto.min-saude.pt; Serviço de Física Médica do Instituto Português de Oncologia do Porto Francisco Gentil, EPE, Porto

2014-07-15

Purpose: An original radionuclide calibrator method for activity determination is presented. The method could be used for intercomparison surveys for short half-life radioactive sources used in Nuclear Medicine, such as{sup 99m}Tc or most positron emission tomography radiopharmaceuticals. Methods: By evaluation of the resulting net optical density (netOD) using a standardized scanning method of irradiated Gafchromic XRQA2 film, a comparison of the netOD measurement with a previously determined calibration curve can be made and the difference between the tested radionuclide calibrator and a radionuclide calibrator used as reference device can be calculated. To estimate the total expected measurement uncertainties, a carefulmore » analysis of the methodology, for the case of{sup 99m}Tc, was performed: reproducibility determination, scanning conditions, and possible fadeout effects. Since every factor of the activity measurement procedure can influence the final result, the method also evaluates correct syringe positioning inside the radionuclide calibrator. Results: As an alternative to using a calibrated source sent to the surveyed site, which requires a relatively long half-life of the nuclide, or sending a portable calibrated radionuclide calibrator, the proposed method uses a source preparedin situ. An indirect activity determination is achieved by the irradiation of a radiochromic film using {sup 99m}Tc under strictly controlled conditions, and cumulated activity calculation from the initial activity and total irradiation time. The irradiated Gafchromic film and the irradiator, without the source, can then be sent to a National Metrology Institute for evaluation of the results. Conclusions: The methodology described in this paper showed to have a good potential for accurate (3%) radionuclide calibrators intercomparison studies for{sup 99m}Tc between Nuclear Medicine centers without source transfer and can easily be adapted to other short half

Intercomparison of HONO Measurements Made Using Wet-Chemical (NITROMAC) and Spectroscopic (IBBCEAS & LP/FAGE) Techniques

NASA Astrophysics Data System (ADS)

Dusanter, S.; Lew, M.; Bottorff, B.; Bechara, J.; Mielke, L. H.; Berke, A.; Raff, J. D.; Stevens, P. S.; Afif, C.

2013-12-01

A good understanding of the oxidative capacity of the atmosphere is important to tackle fundamental issues related to climate change and air quality. The hydroxyl radical (OH) is the dominant oxidant in the daytime troposphere and an accurate description of its sources in atmospheric models is of utmost importance. Recent field studies indicate higher-than-expected concentrations of HONO during the daytime, suggesting that the photolysis of HONO may be an important underestimated source of OH. Understanding the tropospheric HONO budget requires confidence in analytical instrumentation capable of selectively measuring HONO. In this presentation, we discuss an intercomparison study of HONO measurements performed during summer 2013 at the edge of a hardwood forest in Southern Indiana. This exercise involved a wet chemical technique (NITROMAC), an Incoherent Broad-Band Cavity Enhanced Absorption Spectroscopy instrument (IBBCEAS), and a Laser-Photofragmentation/Fluorescence Assay by Gas Expansion instrument (LP/FAGE). The agreement observed between the three techniques will be discussed for both ambient measurements and cross calibration experiments.

The CMIP6 Sea-Ice Model Intercomparison Project (SIMIP): Understanding sea ice through climate-model simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Notz, Dirk; Jahn, Alexandra; Holland, Marika

A better understanding of the role of sea ice for the changing climate of our planet is the central aim of the diagnostic Coupled Model Intercomparison Project 6 (CMIP6)-endorsed Sea-Ice Model Intercomparison Project (SIMIP). To reach this aim, SIMIP requests sea-ice-related variables from climate-model simulations that allow for a better understanding and, ultimately, improvement of biases and errors in sea-ice simulations with large-scale climate models. This then allows us to better understand to what degree CMIP6 model simulations relate to reality, thus improving our confidence in answering sea-ice-related questions based on these simulations. Furthermore, the SIMIP protocol provides a standardmore » for sea-ice model output that will streamline and hence simplify the analysis of the simulated sea-ice evolution in research projects independent of CMIP. To reach its aims, SIMIP provides a structured list of model output that allows for an examination of the three main budgets that govern the evolution of sea ice, namely the heat budget, the momentum budget, and the mass budget. Furthermore, we explain the aims of SIMIP in more detail and outline how its design allows us to answer some of the most pressing questions that sea ice still poses to the international climate-research community.« less

The CMIP6 Sea-Ice Model Intercomparison Project (SIMIP): Understanding sea ice through climate-model simulations

DOE PAGES

Notz, Dirk; Jahn, Alexandra; Holland, Marika; ...

2016-09-23

A better understanding of the role of sea ice for the changing climate of our planet is the central aim of the diagnostic Coupled Model Intercomparison Project 6 (CMIP6)-endorsed Sea-Ice Model Intercomparison Project (SIMIP). To reach this aim, SIMIP requests sea-ice-related variables from climate-model simulations that allow for a better understanding and, ultimately, improvement of biases and errors in sea-ice simulations with large-scale climate models. This then allows us to better understand to what degree CMIP6 model simulations relate to reality, thus improving our confidence in answering sea-ice-related questions based on these simulations. Furthermore, the SIMIP protocol provides a standardmore » for sea-ice model output that will streamline and hence simplify the analysis of the simulated sea-ice evolution in research projects independent of CMIP. To reach its aims, SIMIP provides a structured list of model output that allows for an examination of the three main budgets that govern the evolution of sea ice, namely the heat budget, the momentum budget, and the mass budget. Furthermore, we explain the aims of SIMIP in more detail and outline how its design allows us to answer some of the most pressing questions that sea ice still poses to the international climate-research community.« less

The Joint Experiment for Crop Assessment and Monitoring (JECAM): Synthetic Aperture Radar (SAR) Inter-Comparison Experiment

NASA Astrophysics Data System (ADS)

Dingle Robertson, L.; Hosseini, M.; Davidson, A. M.; McNairn, H.

2017-12-01

The Joint Experiment for Crop Assessment and Monitoring (JECAM) is the research and development branch of GEOGLAM (Group on Earth Observations Global Agricultural Monitoring), a G20 initiative to improve the global monitoring of agriculture through the use of Earth Observation (EO) data and remote sensing. JECAM partners represent a diverse network of researchers collaborating towards a set of best practices and recommendations for global agricultural analysis using EO data, with well monitored test sites covering a wide range of agriculture types, cropping systems and climate regimes. Synthetic Aperture Radar (SAR) for crop inventory and condition monitoring offers many advantages particularly the ability to collect data under cloudy conditions. The JECAM SAR Inter-Comparison Experiment is a multi-year, multi-partner project that aims to compare global methods for (1) operational SAR & optical; multi-frequency SAR; and compact polarimetry methods for crop monitoring and inventory, and (2) the retrieval of Leaf Area Index (LAI) and biomass estimations using models such as the Water Cloud Model (WCM) employing single frequency SAR; multi-frequency SAR; and compact polarimetry. The results from these activities will be discussed along with an examination of the requirements of a global experiment including best-date determination for SAR data acquisition, pre-processing techniques, in situ data sharing, model development and statistical inter-comparison of the results.

A model inter-comparison study to examine limiting factors in modelling Australian tropical savannas

NASA Astrophysics Data System (ADS)

Whitley, Rhys; Beringer, Jason; Hutley, Lindsay B.; Abramowitz, Gab; De Kauwe, Martin G.; Duursma, Remko; Evans, Bradley; Haverd, Vanessa; Li, Longhui; Ryu, Youngryel; Smith, Benjamin; Wang, Ying-Ping; Williams, Mathew; Yu, Qiang

2016-06-01

The savanna ecosystem is one of the most dominant and complex terrestrial biomes, deriving from a distinct vegetative surface comprised of co-dominant tree and grass populations. While these two vegetation types co-exist functionally, demographically they are not static but are dynamically changing in response to environmental forces such as annual fire events and rainfall variability. Modelling savanna environments with the current generation of terrestrial biosphere models (TBMs) has presented many problems, particularly describing fire frequency and intensity, phenology, leaf biochemistry of C3 and C4 photosynthesis vegetation, and root-water uptake. In order to better understand why TBMs perform so poorly in savannas, we conducted a model inter-comparison of six TBMs and assessed their performance at simulating latent energy (LE) and gross primary productivity (GPP) for five savanna sites along a rainfall gradient in northern Australia. Performance in predicting LE and GPP was measured using an empirical benchmarking system, which ranks models by their ability to utilise meteorological driving information to predict the fluxes. On average, the TBMs performed as well as a multi-linear regression of the fluxes against solar radiation, temperature and vapour pressure deficit but were outperformed by a more complicated nonlinear response model that also included the leaf area index (LAI). This identified that the TBMs are not fully utilising their input information effectively in determining savanna LE and GPP and highlights that savanna dynamics cannot be calibrated into models and that there are problems in underlying model processes. We identified key weaknesses in a model's ability to simulate savanna fluxes and their seasonal variation, related to the representation of vegetation by the models and root-water uptake. We underline these weaknesses in terms of three critical areas for development. First, prescribed tree-rooting depths must be deep enough

A qualitative case study of instructional support for web-based simulated laboratory exercises in online college chemistry laboratory courses

NASA Astrophysics Data System (ADS)

Schulman, Kathleen M.

This study fills a gap in the research literature regarding the types of instructional support provided by instructors in online introductory chemistry laboratory courses that employ chemistry simulations as laboratory exercises. It also provides information regarding students' perceptions of the effectiveness of that instructional support. A multiple case study methodology was used to carry out the research. Two online introductory chemistry courses were studied at two community colleges. Data for this study was collected using phone interviews with faculty and student participants, surveys completed by students, and direct observation of the instructional designs of instructional support in the online Blackboard web sites and the chemistry simulations used by the participating institutions. The results indicated that the instructors provided multiple types of instructional support that correlated with forms of effective instructional support identified in the research literature, such as timely detailed feedback, detailed instructions for the laboratory experiments, and consistency in the instructional design of lecture and laboratory course materials, including the chemistry lab simulation environment. The students in one of these courses identified the following as the most effective types of instructional support provided: the instructor's feedback, opportunities to apply chemistry knowledge in the chemistry lab exercises, detailed procedures for the simulated laboratory exercises, the organization of the course Blackboard sites and the chemistry lab simulation web sites, and the textbook homework web sites. Students also identified components of instructional support they felt were missing. These included a desire for more interaction with the instructor, more support for the simulated laboratory exercises from the instructor and the developer of the chemistry simulations, and faster help with questions about the laboratory exercises or experimental

Cloud-resolving model intercomparison of an MC3E squall line case: Part I-Convective updrafts: CRM Intercomparison of a Squall Line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fan, Jiwen; Han, Bin; Varble, Adam

A constrained model intercomparison study of a mid-latitude mesoscale squall line is performed using the Weather Research & Forecasting (WRF) model at 1-km horizontal grid spacing with eight cloud microphysics schemes, to understand specific processes that lead to the large spread of simulated cloud and precipitation at cloud-resolving scales, with a focus of this paper on convective cores. Various observational data are employed to evaluate the baseline simulations. All simulations tend to produce a wider convective area than observed, but a much narrower stratiform area, with most bulk schemes overpredicting radar reflectivity. The magnitudes of the virtual potential temperature drop,more » pressure rise, and the peak wind speed associated with the passage of the gust front are significantly smaller compared with the observations, suggesting simulated cool pools are weaker. Simulations also overestimate the vertical velocity and Ze in convective cores as compared with observational retrievals. The modeled updraft velocity and precipitation have a significant spread across the eight schemes even in this strongly dynamically-driven system. The spread of updraft velocity is attributed to the combined effects of the low-level perturbation pressure gradient determined by cold pool intensity and buoyancy that is not necessarily well correlated to differences in latent heating among the simulations. Variability of updraft velocity between schemes is also related to differences in ice-related parameterizations, whereas precipitation variability increases in no-ice simulations because of scheme differences in collision-coalescence parameterizations.« less

Forward Model Studies of Water Vapor Using Scanning Microwave Radiometers, Global Positioning System, and Radiosondes during the Cloudiness Intercomparison Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattioli, Vinia; Westwater, Ed R.; Gutman, S.

2005-05-01

Brightness temperatures computed from five absorption models and radiosonde observations were analyzed by comparing them with measurements from three microwave radiometers at 23.8 and 31.4 GHz. Data were obtained during the Cloudiness Inter-Comparison experiment at the U.S. Department of Energy's Atmospheric Radiation Measurement Program's (ARM) site in North-Central Oklahoma in 2003. The radiometers were calibrated using two procedures, the so-called instantaneous ?tipcal? method and an automatic self-calibration algorithm. Measurements from the radiometers were in agreement, with less than a 0.4-K difference during clear skies, when the instantaneous method was applied. Brightness temperatures from the radiometer and the radiosonde showed anmore » agreement of less than 0.55 K when the most recent absorption models were considered. Precipitable water vapor (PWV) computed from the radiometers were also compared to the PWV derived from a Global Positioning System station that operates at the ARM site. The instruments agree to within 0.1 cm in PWV retrieval.« less

The Essential Role for Laboratory Studies in Atmospheric Chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burkholder, James B.; Abbatt, Jonathan P. D.; Barnes, Ian

Laboratory studies of atmospheric chemistry characterize the nature of atmospherically relevant processes down to the molecular level, providing fundamental information used to assess how human activities drive environmental phenomena such as climate change, urban air pollution, ecosystem health, indoor air quality, and stratospheric ozone depletion. Laboratory studies have a central role in addressing the incomplete fundamental knowledge of atmospheric chemistry. This paper highlights the evolving science needs for this community and emphasizes how our knowledge is far from complete, hindering our ability to predict the future state of our atmosphere and to respond to emerging global environmental change issues. Finally,more » laboratory studies provide rich opportunities to expand our understanding of the atmosphere via collaborative research with the modeling and field measurement communities, and with neighboring disciplines.« less

The CREW intercomparison of SEVIRI cloud retrievals

NASA Astrophysics Data System (ADS)

Hamann, U.; Walther, A.; Bennartz, R.; Thoss, A.; Meirink, J. M.; Roebeling, R.

2012-12-01

About 70% of the earth's surface is covered with clouds. They strongly influence the radiation balance and the water cycle of the earth. Hence the detailed monitoring of cloud properties - such as cloud fraction, cloud top temperature, cloud particle size, and cloud water path - is important to understand the role of clouds in the weather and the climate system. The remote sensing with passive sensors is an essential mean for the global observation of the cloud parameters, but is nevertheless challenging. This presentation focuses on the inter-comparison and validation of cloud physical properties retrievals from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard METEOSAT. For this study we use retrievals from 12 state-of-art algorithms (Eumetsat, KNMI, NASA Langley, NASA Goddard, University Madison/Wisconsin, DWD, DLR, Meteo-France, KMI, FU Berlin, UK MetOffice) that are made available through the common database of the CREW (Cloud Retrieval Evaluation Working) group. Cloud detection, cloud top phase, height, and temperature, as well as optical properties and water path are validated with CLOUDSAT, CALIPSO, MISR, and AMSR-E measurements. Special emphasis is given to challenging retrieval conditions. Semi-transparent clouds over the earth's surface or another cloud layer modify the measured brightness temperature and increase the retrieval uncertainty. The consideration of the three-dimensional radiative effects is especially important for large viewing angles and broken cloud fields. Aerosols might be misclassified as cloud and may increase the retrieval uncertainty, too. Due to the availability of the high number of sophisticated retrieval datasets, the advantages of different retrieval approaches can be examined and suggestions for future retrieval developments can be made. We like to thank Eumetsat for sponsoring the CREW project including this work.nstitutes that participate in the CREW project.

Multi-Model Combination techniques for Hydrological Forecasting: Application to Distributed Model Intercomparison Project Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ajami, N K; Duan, Q; Gao, X

2005-04-11

This paper examines several multi-model combination techniques: the Simple Multi-model Average (SMA), the Multi-Model Super Ensemble (MMSE), Modified Multi-Model Super Ensemble (M3SE) and the Weighted Average Method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All of the multi-model combination results were obtained using uncalibrated DMIP model outputs and were compared against the best uncalibrated as well as the best calibrated individual model results. The purpose of this study is to understand how different combination techniquesmore » affect the skill levels of the multi-model predictions. This study revealed that the multi-model predictions obtained from uncalibrated single model predictions are generally better than any single member model predictions, even the best calibrated single model predictions. Furthermore, more sophisticated multi-model combination techniques that incorporated bias correction steps work better than simple multi-model average predictions or multi-model predictions without bias correction.« less

Laboratory Information Management System (LIMS): A case study

NASA Technical Reports Server (NTRS)

Crandall, Karen S.; Auping, Judith V.; Megargle, Robert G.

1987-01-01

In the late 70's, a refurbishment of the analytical laboratories serving the Materials Division at NASA Lewis Research Center was undertaken. As part of the modernization efforts, a Laboratory Information Management System (LIMS) was to be included. Preliminary studies indicated a custom-designed system as the best choice in order to satisfy all of the requirements. A scaled down version of the original design has been in operation since 1984. The LIMS, a combination of computer hardware, provides the chemical characterization laboratory with an information data base, a report generator, a user interface, and networking capabilities. This paper is an account of the processes involved in designing and implementing that LIMS.

A Three-Year Feedback Study of a Remote Laboratory Used in Control Engineering Studies

ERIC Educational Resources Information Center

Chevalier, Amélie; Copot, Cosmin; Ionescu, Clara; De Keyser, Robin

2017-01-01

This paper discusses the results of a feedback study for a remote laboratory used in the education of control engineering students. The goal is to show the effectiveness of the remote laboratory on examination results. To provide an overview, the two applications of the remote laboratory are addressed: 1) the Stewart platform, and 2) the quadruple…

Intercomparison of Open-Path Trace Gas Measurements with Two Dual Frequency Comb Spectrometers

PubMed Central

Waxman, Eleanor M.; Cossel, Kevin C.; Truong, Gar-Wing; Giorgetta, Fabrizio R.; Swann, William C.; Coburn, Sean; Wright, Robert J.; Rieker, Gregory B.; Coddington, Ian; Newbury, Nathan R.

2017-01-01

We present the first quantitative intercomparison between two open-path dual comb spectroscopy (DCS) instruments which were operated across adjacent 2-km open-air paths over a two-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6021 to 6388 cm−1 (1565 to 1661 nm), corresponding to a 367 cm−1 bandwidth, at 0.0067 cm−1 sample spacing. The measured absorption spectra agree with each other to within 5×10−4 without any external calibration of either instrument. The absorption spectra are fit to retrieve concentrations for carbon dioxide (CO2), methane (CH4), water (H2O), and deuterated water (HDO). The retrieved dry mole fractions agree to 0.14% (0.57 ppm) for CO2, 0.35% (7 ppb) for CH4, and 0.40% (36 ppm) for H2O over the two-week measurement campaign, which included 23 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a WMO-calibrated cavity ringdown point sensor located along the path with good agreement. Short-term and long-term differences between the two systems are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the two-week measurement campaign yields diurnal cycles of CO2 and CH4 that are consistent with the presence of local sources of CO2 and absence of local sources of CH4. PMID:29276547

The NASA Reanalysis Ensemble Service - Advanced Capabilities for Integrated Reanalysis Access and Intercomparison

NASA Astrophysics Data System (ADS)

Tamkin, G.; Schnase, J. L.; Duffy, D.; Li, J.; Strong, S.; Thompson, J. H.

2017-12-01

NASA's efforts to advance climate analytics-as-a-service are making new capabilities available to the research community: (1) A full-featured Reanalysis Ensemble Service (RES) comprising monthly means data from multiple reanalysis data sets, accessible through an enhanced set of extraction, analytic, arithmetic, and intercomparison operations. The operations are made accessible through NASA's climate data analytics Web services and our client-side Climate Data Services Python library, CDSlib; (2) A cloud-based, high-performance Virtual Real-Time Analytics Testbed supporting a select set of climate variables. This near real-time capability enables advanced technologies like Spark and Hadoop-based MapReduce analytics over native NetCDF files; and (3) A WPS-compliant Web service interface to our climate data analytics service that will enable greater interoperability with next-generation systems such as ESGF. The Reanalysis Ensemble Service includes the following: - New API that supports full temporal, spatial, and grid-based resolution services with sample queries - A Docker-ready RES application to deploy across platforms - Extended capabilities that enable single- and multiple reanalysis area average, vertical average, re-gridding, standard deviation, and ensemble averages - Convenient, one-stop shopping for commonly used data products from multiple reanalyses including basic sub-setting and arithmetic operations (e.g., avg, sum, max, min, var, count, anomaly) - Full support for the MERRA-2 reanalysis dataset in addition to, ECMWF ERA-Interim, NCEP CFSR, JMA JRA-55 and NOAA/ESRL 20CR… - A Jupyter notebook-based distribution mechanism designed for client use cases that combines CDSlib documentation with interactive scenarios and personalized project management - Supporting analytic services for NASA GMAO Forward Processing datasets - Basic uncertainty quantification services that combine heterogeneous ensemble products with comparative observational products (e

Global reference frame: Intercomparison of results (SLR, VLBI and GPS)

NASA Technical Reports Server (NTRS)

Ma, Chopo; Watkins, Michael M.; Heflin, M.

1994-01-01

The terrestrial reference frame (TRF) is realized by a set of positions and velocities derived from a combination of the three space geodetic techniques, SLR, VLBI and GPS. The standard International TRF is constructed by the International Earth Rotation Service in such a way that it is stable with time and the addition of new data. An adopted model for overall plate motion, NUVEL-1 NNR, defines the conceptual reference frame in which all the plates are moving. In addition to the measurements made between reference points within the space geodetic instruments, it is essential to have accurate, documented eccentricity measurements from the instrument reference points to ground monuments. Proper local surveys between the set of ground monuments at a site are also critical for the use of the space geodetic results. Eccentricities and local surveys are, in fact, the most common and vexing sources of error in the use of the TRF for such activities as collocation and intercomparison.

Knowledge Retention for Computer Simulations: A study comparing virtual and hands-on laboratories

NASA Astrophysics Data System (ADS)

Croom, John R., III

The use of virtual laboratories has the potential to change physics education. These low-cost, interactive computer activities interest students, allow for easy setup, and give educators a way to teach laboratory based online classes. This study investigated whether virtual laboratories could replace traditional hands-on laboratories and whether students could retain the same long-term knowledge in virtual laboratories as compared to hands-on laboratories. This study is a quantitative quasi-experiment that used a multiple posttest design to determine if students using virtual laboratories would retain the same knowledge as students who performed hands-on laboratories after 9 weeks. The study was composed of 336 students from 14 school districts. Students had their performances on the laboratories and their retention of the laboratories compared to a series of factors that might have affected their retention using a pretest and two posttests, which were compared using a t test. The results showed no significant difference in short-term learning between the hands-on laboratory groups and virtual laboratory groups. There was, however, a significant difference (p = .005) between the groups in long-term retention; students in the hands-on laboratory groups retained more information than those in the virtual laboratory groups. These results suggest that long-term learning is enhanced when a laboratory contains a hands-on component. Finally, the results showed that both groups of students felt their particular laboratory style was superior to the alternative method. The findings of this study can be used to improve the integration of virtual laboratories into science curriculum.

Smoke and Emissions Model Intercomparison Project (SEMIP)

NASA Astrophysics Data System (ADS)

Larkin, N. K.; Raffuse, S.; Strand, T.; Solomon, R.; Sullivan, D.; Wheeler, N.

2008-12-01

Fire emissions and smoke impacts from wildland fire are a growing concern due to increasing fire season severity, dwindling tolerance of smoke by the public, tightening air quality regulations, and their role in climate change issues. Unfortunately, while a number of models and modeling system solutions are available to address these issues, the lack of quantitative information on the limitations and difference between smoke and emissions models impedes the use of these tools for real-world applications (JFSP, 2007). We describe a new, open-access project to directly address this issue, the open-access Smoke Emissions Model Intercomparison Project (SEMIP) and invite the community to participate. Preliminary work utilizing the modular BlueSky framework to directly compare fire location and size information, fuel loading amounts, fuel consumption rates, and fire emissions from a number of current models that has found model-to-model variability as high as two orders of magnitude for an individual fire. Fire emissions inventories also show significant variability on both regional and national scales that are dependant on the fire location information used (ground report vs. satellite), the fuel loading maps assumed, and the fire consumption models employed. SEMIP expands on this work and creates an open-access database of model results and observations with the goal of furthering model development and model prediction usability for real-world decision support.

Intercomparison of aerosol-cloud-precipitation interactions in stratiform orographic mixed-phase clouds

NASA Astrophysics Data System (ADS)

Muhlbauer, A.; Hashino, T.; Xue, L.; Teller, A.; Lohmann, U.; Rasmussen, R. M.; Geresdi, I.; Pan, Z.

2010-04-01

Anthropogenic aerosols serve as a source of both cloud condensation nuclei (CCN) and ice nuclei (IN) and affect microphysical properties of clouds. Increasing aerosol number concentrations is hypothesized to retard the cloud droplet collision/coalescence and the riming in mixed-phase clouds, thereby decreasing orographic precipitation. This study presents results from a model intercomparison of 2-D simulations of aerosol-cloud-precipitation interactions in stratiform orographic mixed-phase clouds. The sensitivity of orographic precipitation to changes in the aerosol number concentrations is analyzed and compared for various dynamical and thermodynamical situations. Furthermore, the sensitivities of microphysical processes such as collision/coalescence, aggregation and riming to changes in the aerosol number concentrations are evaluated and compared. The participating models are the Consortium for Small-Scale Modeling's (COSMO) model with bulk-microphysics, the Weather Research and Forecasting (WRF) model with bin-microphysics and the University of Wisconsin modeling system (UWNMS) with a spectral ice-habit prediction microphysics scheme. All models are operated on a cloud-resolving scale with 2 km horizontal grid spacing. The results of the model intercomparison suggest that the sensitivity of orographic precipitation to aerosol modifications varies greatly from case to case and from model to model. Neither a precipitation decrease nor a precipitation increase is found robustly in all simulations. Qualitative robust results can only be found for a subset of the simulations but even then quantitative agreement is scarce. Estimates of the second indirect aerosol effect on orographic precipitation are found to range from -19% to 0% depending on the simulated case and the model. Similarly, riming is shown to decrease in some cases and models whereas it increases in others which implies that a decrease in riming with increasing aerosol load is not a robust result

Intercomparison of aerosol-cloud-precipitation interactions in stratiform orographic mixed-phase clouds

NASA Astrophysics Data System (ADS)

Muhlbauer, A.; Hashino, T.; Xue, L.; Teller, A.; Lohmann, U.; Rasmussen, R. M.; Geresdi, I.; Pan, Z.

2010-09-01

Anthropogenic aerosols serve as a source of both cloud condensation nuclei (CCN) and ice nuclei (IN) and affect microphysical properties of clouds. Increasing aerosol number concentrations is hypothesized to retard the cloud droplet coalescence and the riming in mixed-phase clouds, thereby decreasing orographic precipitation. This study presents results from a model intercomparison of 2-D simulations of aerosol-cloud-precipitation interactions in stratiform orographic mixed-phase clouds. The sensitivity of orographic precipitation to changes in the aerosol number concentrations is analysed and compared for various dynamical and thermodynamical situations. Furthermore, the sensitivities of microphysical processes such as coalescence, aggregation, riming and diffusional growth to changes in the aerosol number concentrations are evaluated and compared. The participating numerical models are the model from the Consortium for Small-Scale Modeling (COSMO) with bulk microphysics, the Weather Research and Forecasting (WRF) model with bin microphysics and the University of Wisconsin modeling system (UWNMS) with a spectral ice habit prediction microphysics scheme. All models are operated on a cloud-resolving scale with 2 km horizontal grid spacing. The results of the model intercomparison suggest that the sensitivity of orographic precipitation to aerosol modifications varies greatly from case to case and from model to model. Neither a precipitation decrease nor a precipitation increase is found robustly in all simulations. Qualitative robust results can only be found for a subset of the simulations but even then quantitative agreement is scarce. Estimates of the aerosol effect on orographic precipitation are found to range from -19% to 0% depending on the simulated case and the model. Similarly, riming is shown to decrease in some cases and models whereas it increases in others, which implies that a decrease in riming with increasing aerosol load is not a robust result

Sao Paulo Lightning Mapping Array (SP-LMA): Network Assessment and Analyses for Intercomparison Studies and GOES-R Proxy Activities

NASA Technical Reports Server (NTRS)

Blakeslee, R. J.; Bailey, J. C.; Carey, L. D.; Goodman, S. J.; Rudlosky, S. D.; Albrecht, R.; Morales, C. A.; Anselmo, E. M.; Neves, J. R.

2013-01-01

A 12 station Lightning Mapping Array (LMA) network was deployed during October 2011in the vicinity of São Paulo, Brazil (SP-LMA) to contribute total lightning measurements to an international field campaign [CHUVA - Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GPM (GlobAl Precipitation Measurement)]. The SP-LMA was operational from November 2011 through March 2012. Sensor spacing was on the order of 15-30 km, with a network diameter on the order of 40-50km. The SP-LMA provides good 3-D lightning mapping out to150 km from the network center, with 2-D coverage considerably farther. In addition to supporting CHUVA science/mission objectives, the SP-LMA is supporting the generation of unique proxy data for the Geostationary Lightning Mapper (GLM) and Advanced Baseline Imager (ABI), on NOAA's Geostationary Operational Environmental Satellite-R (GOES-R: scheduled for a 2015 launch). These proxy data will be used to develop and validate operational algorithms so that they will be ready to use on "day1" following the GOES-R launch. The SP-LMA data also will be intercompared with lightning observations from other deployed lightning networks to advance our understanding of the capabilities/contributions of each of these networks toward GLM proxy and validation activities. This paper addresses the network assessment and analyses for intercomparison studies and GOES-R proxy activities

21 CFR 58.185 - Reporting of nonclinical laboratory study results.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Reporting of nonclinical laboratory study results. (a) A final report shall be prepared for each nonclinical...

21 CFR 58.185 - Reporting of nonclinical laboratory study results.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Reporting of nonclinical laboratory study results. (a) A final report shall be prepared for each nonclinical...

21 CFR 58.185 - Reporting of nonclinical laboratory study results.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Reporting of nonclinical laboratory study results. 58.185 Section 58.185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Reporting of nonclinical laboratory study results. (a) A final report shall be prepared for each nonclinical...

Test Bed Doppler Wind Lidar and Intercomparison Facility At NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Kavaya, Michael J.; Koch, Grady J.; Petros, Mulugeta; Barnes, Bruce W.; Beyon, Jeffrey; Amzajerdian, Farzin; Yu, Ji-Rong; Singh, Upendra N.

2004-01-01

State of the art 2-micron lasers and other lidar components under development by NASA are being demonstrated and validated in a mobile test bed Doppler wind lidar. A lidar intercomparison facility has been developed to ensure parallel alignment of up to 4 Doppler lidar systems while measuring wind. Investigations of the new components; their operation in a complete system; systematic and random errors; the hybrid (joint coherent and direct detection) approach to global wind measurement; and atmospheric wind behavior are planned. Future uses of the VALIDAR (VALIDation LIDAR) mobile lidar may include comparison with the data from an airborne Doppler wind lidar in preparation for validation by the airborne system of an earth orbiting Doppler wind lidar sensor.

Seeking excellence: An evaluation of 235 international laboratories conducting water isotope analyses by isotope-ratio and laser-absorption spectrometry.

PubMed

Wassenaar, L I; Terzer-Wassmuth, S; Douence, C; Araguas-Araguas, L; Aggarwal, P K; Coplen, T B

2018-03-15

Water stable isotope ratios (δ 2 H and δ 18 O values) are widely used tracers in environmental studies; hence, accurate and precise assays are required for providing sound scientific information. We tested the analytical performance of 235 international laboratories conducting water isotope analyses using dual-inlet and continuous-flow isotope ratio mass spectrometers and laser spectrometers through a water isotope inter-comparison test. Eight test water samples were distributed by the IAEA to international stable isotope laboratories. These consisted of a core set of five samples spanning the common δ-range of natural waters, and three optional samples (highly depleted, enriched, and saline). The fifth core sample contained unrevealed trace methanol to assess analyst vigilance to the impact of organic contamination on water isotopic measurements made by all instrument technologies. For the core and optional samples ~73 % of laboratories gave acceptable results within 0.2 ‰ and 1.5 ‰ of the reference values for δ 18 O and δ 2 H, respectively; ~27 % produced unacceptable results. Top performance for δ 18 O values was dominated by dual-inlet IRMS laboratories; top performance for δ 2 H values was led by laser spectrometer laboratories. Continuous-flow instruments yielded comparatively intermediate results. Trace methanol contamination of water resulted in extreme outlier δ-values for laser instruments, but also affected reactor-based continuous-flow IRMS systems; however, dual-inlet IRMS δ-values were unaffected. Analysis of the laboratory results and their metadata suggested inaccurate or imprecise performance stemmed mainly from skill- and knowledge-based errors including: calculation mistakes, inappropriate or compromised laboratory calibration standards, poorly performing instrumentation, lack of vigilance to contamination, or inattention to unreasonable isotopic outcomes. To counteract common errors, we recommend that laboratories include 1-2 'known

Seeking excellence: An evaluation of 235 international laboratories conducting water isotope analyses by isotope-ratio and laser-absorption spectrometry

USGS Publications Warehouse

Wassenaar, L. I.; Terzer-Wassmuth, S.; Douence, C.; Araguas-Araguas, L.; Aggarwal, P. K.; Coplen, Tyler B.

2018-01-01

RationaleWater stable isotope ratios (δ2H and δ18O values) are widely used tracers in environmental studies; hence, accurate and precise assays are required for providing sound scientific information. We tested the analytical performance of 235 international laboratories conducting water isotope analyses using dual-inlet and continuous-flow isotope ratio mass spectrometers and laser spectrometers through a water isotope inter-comparison test.MethodsEight test water samples were distributed by the IAEA to international stable isotope laboratories. These consisted of a core set of five samples spanning the common δ-range of natural waters, and three optional samples (highly depleted, enriched, and saline). The fifth core sample contained unrevealed trace methanol to assess analyst vigilance to the impact of organic contamination on water isotopic measurements made by all instrument technologies.ResultsFor the core and optional samples ~73 % of laboratories gave acceptable results within 0.2 ‰ and 1.5 ‰ of the reference values for δ18O and δ2H, respectively; ~27 % produced unacceptable results. Top performance for δ18O values was dominated by dual-inlet IRMS laboratories; top performance for δ2H values was led by laser spectrometer laboratories. Continuous-flow instruments yielded comparatively intermediate results. Trace methanol contamination of water resulted in extreme outlier δ-values for laser instruments, but also affected reactor-based continuous-flow IRMS systems; however, dual-inlet IRMS δ-values were unaffected.ConclusionsAnalysis of the laboratory results and their metadata suggested inaccurate or imprecise performance stemmed mainly from skill- and knowledge-based errors including: calculation mistakes, inappropriate or compromised laboratory calibration standards, poorly performing instrumentation, lack of vigilance to contamination, or inattention to unreasonable isotopic outcomes. To counteract common errors, we recommend that

Visible light nitrogen dioxide spectrophotometer intercomparison: Mount Kobau, British Columbia, July 28 to August 10, 1991

NASA Technical Reports Server (NTRS)

Mcelroy, C. T.; Elokhov, A. S.; Elansky, N.; Frank, H.; Johnston, P.; Kerr, J. B.

1994-01-01

Under the auspices of the World Meteorological Organization, Environment Canada hosted an international comparison of visible light spectrophotometers at Mt. Kobau, British Columbia in August of 1991. Instruments from four countries were involved. The intercomparison results have indicated that some significant differences exist in the responses of the various instruments, and have provided a basis for the comparison of the historical data sets which currently exist as a result of the independent researches carried out in the past in the former Soviet Union, New Zealand, and Canada.

Intercomparison of Streamflow Simulations between WRF-Hydro and Hydrology Laboratory-Research Distributed Hydrologic Model Frameworks

NASA Astrophysics Data System (ADS)

KIM, J.; Smith, M. B.; Koren, V.; Salas, F.; Cui, Z.; Johnson, D.

2017-12-01

The National Oceanic and Atmospheric Administration (NOAA)-National Weather Service (NWS) developed the Hydrology Laboratory-Research Distributed Hydrologic Model (HL-RDHM) framework as an initial step towards spatially distributed modeling at River Forecast Centers (RFCs). Recently, the NOAA/NWS worked with the National Center for Atmospheric Research (NCAR) to implement the National Water Model (NWM) for nationally-consistent water resources prediction. The NWM is based on the WRF-Hydro framework and is run at a 1km spatial resolution and 1-hour time step over the contiguous United States (CONUS) and contributing areas in Canada and Mexico. In this study, we compare streamflow simulations from HL-RDHM and WRF-Hydro to observations from 279 USGS stations. For streamflow simulations, HL-RDHM is run on 4km grids with the temporal resolution of 1 hour for a 5-year period (Water Years 2008-2012), using a priori parameters provided by NOAA-NWS. The WRF-Hydro streamflow simulations for the same time period are extracted from NCAR's 23 retrospective run of the NWM (version 1.0) over CONUS based on 1km grids. We choose 279 USGS stations which are relatively less affected by dams or reservoirs, in the domains of six different RFCs. We use the daily average values of simulations and observations for the convenience of comparison. The main purpose of this research is to evaluate how HL-RDHM and WRF-Hydro perform at USGS gauge stations. We compare daily time-series of observations and both simulations, and calculate the error values using a variety of error functions. Using these plots and error values, we evaluate the performances of HL-RDHM and WRF-Hydro models. Our results show a mix of model performance across geographic regions.

Successful Sampling Strategy Advances Laboratory Studies of NMR Logging in Unconsolidated Aquifers

NASA Astrophysics Data System (ADS)

Behroozmand, Ahmad A.; Knight, Rosemary; Müller-Petke, Mike; Auken, Esben; Barfod, Adrian A. S.; Ferré, Ty P. A.; Vilhelmsen, Troels N.; Johnson, Carole D.; Christiansen, Anders V.

2017-11-01

The nuclear magnetic resonance (NMR) technique has become popular in groundwater studies because it responds directly to the presence and mobility of water in a porous medium. There is a need to conduct laboratory experiments to aid in the development of NMR hydraulic conductivity models, as is typically done in the petroleum industry. However, the challenge has been obtaining high-quality laboratory samples from unconsolidated aquifers. At a study site in Denmark, we employed sonic drilling, which minimizes the disturbance of the surrounding material, and extracted twelve 7.6 cm diameter samples for laboratory measurements. We present a detailed comparison of the acquired laboratory and logging NMR data. The agreement observed between the laboratory and logging data suggests that the methodologies proposed in this study provide good conditions for studying NMR measurements of unconsolidated near-surface aquifers. Finally, we show how laboratory sample size and condition impact the NMR measurements.

A Science Librarian in the Laboratory: A Case Study

ERIC Educational Resources Information Center

Tomaszewski, Robert

2011-01-01

A science librarian in the laboratory can become a "point of access" for database instruction and provide a learning opportunity for students to develop their information literacy skills. A case study describes how a librarian in an organic chemistry laboratory helps the class run smoothly and identifies the science librarian as an ally and a…

Community Intercomparison Suite (CIS) v1.4.0: a tool for intercomparing models and observations

NASA Astrophysics Data System (ADS)

Watson-Parris, Duncan; Schutgens, Nick; Cook, Nicholas; Kipling, Zak; Kershaw, Philip; Gryspeerdt, Edward; Lawrence, Bryan; Stier, Philip

2016-09-01

The Community Intercomparison Suite (CIS) is an easy-to-use command-line tool which has been developed to allow the straightforward intercomparison of remote sensing, in situ and model data. While there are a number of tools available for working with climate model data, the large diversity of sources (and formats) of remote sensing and in situ measurements necessitated a novel software solution. Developed by a professional software company, CIS supports a large number of gridded and ungridded data sources "out-of-the-box", including climate model output in NetCDF or the UK Met Office pp file format, CloudSat, CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization), MODIS (MODerate resolution Imaging Spectroradiometer), Cloud and Aerosol CCI (Climate Change Initiative) level 2 satellite data and a number of in situ aircraft and ground station data sets. The open-source architecture also supports user-defined plugins to allow many other sources to be easily added. Many of the key operations required when comparing heterogenous data sets are provided by CIS, including subsetting, aggregating, collocating and plotting the data. Output data are written to CF-compliant NetCDF files to ensure interoperability with other tools and systems. The latest documentation, including a user manual and installation instructions, can be found on our website (http://cistools.net). Here, we describe the need which this tool fulfils, followed by descriptions of its main functionality (as at version 1.4.0) and plugin architecture which make it unique in the field.

The Carbon Dioxide Removal Model Intercomparison Project (CDRMIP): rationale and experimental protocol for CMIP6

NASA Astrophysics Data System (ADS)

Keller, David P.; Lenton, Andrew; Scott, Vivian; Vaughan, Naomi E.; Bauer, Nico; Ji, Duoying; Jones, Chris D.; Kravitz, Ben; Muri, Helene; Zickfeld, Kirsten

2018-03-01

The recent IPCC reports state that continued anthropogenic greenhouse gas emissions are changing the climate, threatening severe, pervasive and irreversible impacts. Slow progress in emissions reduction to mitigate climate change is resulting in increased attention to what is called geoengineering, climate engineering, or climate intervention - deliberate interventions to counter climate change that seek to either modify the Earth's radiation budget or remove greenhouse gases such as CO2 from the atmosphere. When focused on CO2, the latter of these categories is called carbon dioxide removal (CDR). Future emission scenarios that stay well below 2 °C, and all emission scenarios that do not exceed 1.5 °C warming by the year 2100, require some form of CDR. At present, there is little consensus on the climate impacts and atmospheric CO2 reduction efficacy of the different types of proposed CDR. To address this need, the Carbon Dioxide Removal Model Intercomparison Project (or CDRMIP) was initiated. This project brings together models of the Earth system in a common framework to explore the potential, impacts, and challenges of CDR. Here, we describe the first set of CDRMIP experiments, which are formally part of the 6th Coupled Model Intercomparison Project (CMIP6). These experiments are designed to address questions concerning CDR-induced climate reversibility, the response of the Earth system to direct atmospheric CO2 removal (direct air capture and storage), and the CDR potential and impacts of afforestation and reforestation, as well as ocean alkalinization.>

The Carbon Dioxide Removal Model Intercomparison Project (CDRMIP): rationale and experimental protocol for CMIP6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, David P.; Lenton, Andrew; Scott, Vivian

The recent IPCC reports state that continued anthropogenic greenhouse gas emissions are changing the climate, threatening severe, pervasive and irreversible impacts. Slow progress in emissions reduction to mitigate climate change is resulting in increased attention to what is called geoengineering, climate engineering, or climate intervention – deliberate interventions to counter climate change that seek to either modify the Earth's radiation budget or remove greenhouse gases such as CO 2 from the atmosphere. When focused on CO 2, the latter of these categories is called carbon dioxide removal (CDR). Future emission scenarios that stay well below 2 °C, and all emissionmore » scenarios that do not exceed 1.5 °C warming by the year 2100, require some form of CDR. At present, there is little consensus on the climate impacts and atmospheric CO 2 reduction efficacy of the different types of proposed CDR. To address this need, the Carbon Dioxide Removal Model Intercomparison Project (or CDRMIP) was initiated. This project brings together models of the Earth system in a common framework to explore the potential, impacts, and challenges of CDR. Here, we describe the first set of CDRMIP experiments, which are formally part of the 6th Coupled Model Intercomparison Project (CMIP6). These experiments are designed to address questions concerning CDR-induced climate reversibility, the response of the Earth system to direct atmospheric CO 2 removal (direct air capture and storage), and the CDR potential and impacts of afforestation and reforestation, as well as ocean alkalinization.>« less

Cloud-resolving model intercomparison of an MC3E squall line case: Part I-Convective updrafts: CRM Intercomparison of a Squall Line

DOE PAGES

Fan, Jiwen; Han, Bin; Varble, Adam; ...

2017-09-06

An intercomparison study of a midlatitude mesoscale squall line is performed using the Weather Research and Forecasting (WRF) model at 1 km horizontal grid spacing with eight different cloud microphysics schemes to investigate processes that contribute to the large variability in simulated cloud and precipitation properties. All simulations tend to produce a wider area of high radar reflectivity (Z e > 45 dBZ) than observed but a much narrower stratiform area. Furthermore, the magnitude of the virtual potential temperature drop associated with the gust front passage is similar in simulations and observations, while the pressure rise and peak wind speedmore » are smaller than observed, possibly suggesting that simulated cold pools are shallower than observed. Most of the microphysics schemes overestimate vertical velocity and Z e in convective updrafts as compared with observational retrievals. Simulated precipitation rates and updraft velocities have significant variability across the eight schemes, even in this strongly dynamically driven system. Differences in simulated updraft velocity correlate well with differences in simulated buoyancy and low-level vertical perturbation pressure gradient, which appears related to cold pool intensity that is controlled by the evaporation rate. Simulations with stronger updrafts have a more optimal convective state, with stronger cold pools, ambient low-level vertical wind shear, and rear-inflow jets. We found that updraft velocity variability between schemes is mainly controlled by differences in simulated ice-related processes, which impact the overall latent heating rate, whereas surface rainfall variability increases in no-ice simulations mainly because of scheme differences in collision-coalescence parameterizations.« less

Zero-gravity cloud physics laboratory: Candidate experiments definition and preliminary concept studies

NASA Technical Reports Server (NTRS)

Eaton, L. R.; Greco, R. V.; Hollinden, A. B.

1973-01-01

The candidate definition studies on the zero-g cloud physics laboratory are covered. This laboratory will be an independent self-contained shuttle sortie payload. Several critical technology areas have been identified and studied to assure proper consideration in terms of engineering requirements for the final design. Areas include chambers, gas and particle generators, environmental controls, motion controls, change controls, observational techniques, and composition controls. This unique laboratory will allow studies to be performed without mechanical, aerodynamics, electrical, or other type techniques to support the object under study. This report also covers the candidate experiment definitions, chambers and experiment classes, laboratory concepts and plans, special supporting studies, early flight opportunities and payload planning data for overall shuttle payload requirements assessments.

Laboratory Studies of Interstellar PAH Analogs

NASA Technical Reports Server (NTRS)

Salama, Farid; DeVincenzi, Donald (Technical Monitor)

2000-01-01

Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a

Intercomparison of near real time monitors of PM2.5 nitrate and sulfate at the U.S. Environmental Protection Agency Atlanta Supersite

NASA Astrophysics Data System (ADS)

Weber, R.; Orsini, D.; Duan, Y.; Baumann, K.; Kiang, C. S.; Chameides, W.; Lee, Y. N.; Brechtel, F.; Klotz, P.; Jongejan, P.; ten Brink, H.; Slanina, J.; Boring, C. B.; Genfa, Z.; Dasgupta, P.; Hering, S.; Stolzenburg, M.; Dutcher, D. D.; Edgerton, E.; Hartsell, B.; Solomon, P.; Tanner, R.

2003-04-01

Five new instruments for semicontinuous measurements of fine particle (PM2.5) nitrate and sulfate were deployed in the Atlanta Supersite Experiment during an intensive study in August 1999. The instruments measured bulk aerosol chemical composition at rates ranging from every 5 min to once per hour. The techniques included a filter sampling system with automated water extraction and online ion chromatographic (IC) analysis, two systems that directly collected particles into water for IC analysis, and two techniques that converted aerosol nitrate or sulfate either catalytically or by flash vaporization to gaseous products that were measured with gas analyzers. During the one-month study, 15-min integrated nitrate concentrations were low, ranging from about 0.1 to 3.5 μg m-3 with a mean value of 0.5 μg m-3. Ten-minute integrated sulfate concentrations varied between 0.3 and 40 μg m-3 with a mean of 14 μg m-3. By the end of the one-month study most instruments were in close agreement, with r-squared values between instrument pairs typically ranging from 0.7 to 0.94. Based on comparison between individual semicontinuous devices and 24-hour integrated filter measurements, most instruments were within 20-30% for nitrate (˜0.1-0.2 μg m-3) and 10-15% for sulfate (1-2 μg m-3). Within 95% confidence intervals, linear regression fits suggest that no biases existed between the semicontinuous techniques and the 24-hour integrated filter measurements of nitrate and sulfate;, however, for nitrate, the semicontinuous intercomparisons showed significantly less variability than intercomparisons amongst the 24-hour integrated filters.

An intercomparison of instrumentation for tropospheric measurements of dimethyl sulfide: Aircraft results for concentrations at the parts-per-trillion level

NASA Technical Reports Server (NTRS)

Gregory, Gerald L.; Warren, Linda S.; Davis, Douglas D.; Andreae, Meinrat O.; Bandy, Alan R.; Ferek, Ronald J.; Johnson, James E.; Saltzman, Eric S.; Cooper, David J.

1993-01-01

This paper reports results from NASA's Chemical Instrumentation and Test Evaluation (CITE 3) during which airborne measurements of dimethyl sulfide (DMS) from six instruments were intercompared. Represented by the six instruments are three fundamentally different detection principles (flame photometric, mass spectrometric, and electron capture after fluorination); three collection/preconcentration methods (cryogenic, gold wool absorption, and polymer absorbent); and three types of oxidant scrubbers (solid phase alkaline, aqueous reactor, and cotton). The measurements were made over the Atlantic Ocean in August/September 1989 during flights from NASA's Wallops Flight Center, Virginia, and Natal, Brazil. The majority of the intercomparisons are at DMS mixing ratios less than 50 pptv. Results show that instrument agreement is of the order of a few pptv for mixing ratios less than 50 pptv and to within about 15% above 50 pptv. Statistically significant (95% confidence) measurement biases were noted among some of the techniques. However, in all cases, any bias is small and within the accuracy of the measurements and prepared DMS standards. Thus, we conclude that the techniques intercompared during CITE 3 provide equally valid measurements of DMS in the range of a few pptv to 100 pptv (upper range of the intercomparisons).

Intercomparison of six ambient [CH2O] measurement techniques

NASA Astrophysics Data System (ADS)

Gilpin, Tim; Apel, Eric; Fried, Alan; Wert, Bryan; Calvert, Jack; Genfa, Zhang; Dasgupta, Purnendu; Harder, Jerry W.; Heikes, Brian; Hopkins, Brian; Westberg, Hal; Kleindienst, Tad; Lee, Yin-Nan; Zhou, Xianliang; Lonneman, William; Sewell, Scott

1997-09-01

From May 29 to June 3, 1995 a blind intercomparison of six ambient formaldehyde measurement techniques took place at a field site near the National Center for Atmospheric Research in Boulder, Colorado. The continuous measurement methods intercompared were tunable diode laser absorption spectroscopy, (TDLAS); coil/2,4-dinitrophenylhydrazine, (CDNPH); 1,3-cyclohexanedione-diffusion scrubber (CHDDS); and the coil enzyme method (CENZ). In addition, two different cartridge methods were compared: silica gel-2,4-dinitrophenylhydrazine (DPNH) systems and a C-18-DNPH system. The intercomparison was conducted with spiked zero air (part 1) and ambient air (part 2). The CH2O standards for part 1 were calibrated by several independent methods and delivered to participants via a common glass manifold with potential trace gas interférants common to ambient air (O3, SO2, NO2, isoprene, H2O). The TDLAS system was used to confirm the absolute accuracy of the standards and served as a mission reference for part 1. The ambient phase lasted 44 hours with all participants sampling from a common glass tower. Differences between the ambient [CH2O] observed by the TDLAS and the other continuous methods were significant in some cases. For matched ambient measurement times the average ratios (±1σ) [CH2O]measured/[CH2O]TDLAS were: 0.89±0.12 (CDNPH); 1.30±0.02 (CHDDS); 0.63±0.03 (CENZ). The methods showed similar variations but different absolute values and the divergences appeared to result largely from calibration differences (no gas phase standards were used by groups other than NCAR). When the regressions of the participant [CH2O] values versus the TDLAS values, (measured in part 1), were used to normalize all of the results to the common gas phase standards of the NCAR group, the average ratios (±1σ), [CH2O]corrected/[CH2O]TDLAS for the first measurement period were much closer to unity: 1.04±0.14 (CDNPH), 1.00±0.11 (CHDDS), and 0.82±0.08 (CENZ). With the continuous methods

Host model uncertainties in aerosol radiative forcing estimates: results from the AeroCom prescribed intercomparison study

NASA Astrophysics Data System (ADS)

Stier, P.; Schutgens, N. A. J.; Bian, H.; Boucher, O.; Chin, M.; Ghan, S.; Huneeus, N.; Kinne, S.; Lin, G.; Myhre, G.; Penner, J. E.; Randles, C.; Samset, B.; Schulz, M.; Yu, H.; Zhou, C.

2012-09-01

Simulated multi-model "diversity" in aerosol direct radiative forcing estimates is often perceived as measure of aerosol uncertainty. However, current models used for aerosol radiative forcing calculations vary considerably in model components relevant for forcing calculations and the associated "host-model uncertainties" are generally convoluted with the actual aerosol uncertainty. In this AeroCom Prescribed intercomparison study we systematically isolate and quantify host model uncertainties on aerosol forcing experiments through prescription of identical aerosol radiative properties in nine participating models. Even with prescribed aerosol radiative properties, simulated clear-sky and all-sky aerosol radiative forcings show significant diversity. For a purely scattering case with globally constant optical depth of 0.2, the global-mean all-sky top-of-atmosphere radiative forcing is -4.51 W m-2 and the inter-model standard deviation is 0.70 W m-2, corresponding to a relative standard deviation of 15%. For a case with partially absorbing aerosol with an aerosol optical depth of 0.2 and single scattering albedo of 0.8, the forcing changes to 1.26 W m-2, and the standard deviation increases to 1.21 W m-2, corresponding to a significant relative standard deviation of 96%. However, the top-of-atmosphere forcing variability owing to absorption is low, with relative standard deviations of 9% clear-sky and 12% all-sky. Scaling the forcing standard deviation for a purely scattering case to match the sulfate radiative forcing in the AeroCom Direct Effect experiment, demonstrates that host model uncertainties could explain about half of the overall sulfate forcing diversity of 0.13 W m-2 in the AeroCom Direct Radiative Effect experiment. Host model errors in aerosol radiative forcing are largest in regions of uncertain host model components, such as stratocumulus cloud decks or areas with poorly constrained surface albedos, such as sea ice. Our results demonstrate that host

Host model uncertainties in aerosol radiative forcing estimates: results from the AeroCom Prescribed intercomparison study

NASA Astrophysics Data System (ADS)

Stier, P.; Schutgens, N. A. J.; Bellouin, N.; Bian, H.; Boucher, O.; Chin, M.; Ghan, S.; Huneeus, N.; Kinne, S.; Lin, G.; Ma, X.; Myhre, G.; Penner, J. E.; Randles, C. A.; Samset, B.; Schulz, M.; Takemura, T.; Yu, F.; Yu, H.; Zhou, C.

2013-03-01

Simulated multi-model "diversity" in aerosol direct radiative forcing estimates is often perceived as a measure of aerosol uncertainty. However, current models used for aerosol radiative forcing calculations vary considerably in model components relevant for forcing calculations and the associated "host-model uncertainties" are generally convoluted with the actual aerosol uncertainty. In this AeroCom Prescribed intercomparison study we systematically isolate and quantify host model uncertainties on aerosol forcing experiments through prescription of identical aerosol radiative properties in twelve participating models. Even with prescribed aerosol radiative properties, simulated clear-sky and all-sky aerosol radiative forcings show significant diversity. For a purely scattering case with globally constant optical depth of 0.2, the global-mean all-sky top-of-atmosphere radiative forcing is -4.47 Wm-2 and the inter-model standard deviation is 0.55 Wm-2, corresponding to a relative standard deviation of 12%. For a case with partially absorbing aerosol with an aerosol optical depth of 0.2 and single scattering albedo of 0.8, the forcing changes to 1.04 Wm-2, and the standard deviation increases to 1.01 W-2, corresponding to a significant relative standard deviation of 97%. However, the top-of-atmosphere forcing variability owing to absorption (subtracting the scattering case from the case with scattering and absorption) is low, with absolute (relative) standard deviations of 0.45 Wm-2 (8%) clear-sky and 0.62 Wm-2 (11%) all-sky. Scaling the forcing standard deviation for a purely scattering case to match the sulfate radiative forcing in the AeroCom Direct Effect experiment demonstrates that host model uncertainties could explain about 36% of the overall sulfate forcing diversity of 0.11 Wm-2 in the AeroCom Direct Radiative Effect experiment. Host model errors in aerosol radiative forcing are largest in regions of uncertain host model components, such as stratocumulus

Uranium adsorption on weathered schist - Intercomparison of modeling approaches

USGS Publications Warehouse

Payne, T.E.; Davis, J.A.; Ochs, M.; Olin, M.; Tweed, C.J.

2004-01-01

Experimental data for uranium adsorption on a complex weathered rock were simulated by twelve modelling teams from eight countries using surface complexation (SC) models. This intercomparison was part of an international project to evaluate the present capabilities and limitations of SC models in representing sorption by geologic materials. The models were assessed in terms of their predictive ability, data requirements, number of optimised parameters, ability to simulate diverse chemical conditions and transferability to other substrates. A particular aim was to compare the generalised composite (GC) and component additivity (CA) approaches for modelling sorption by complex substrates. Both types of SC models showed a promising capability to simulate sorption data obtained across a range of chemical conditions. However, the models incorporated a wide variety of assumptions, particularly in terms of input parameters such as site densities and surface site types. Furthermore, the methods used to extrapolate the model simulations to different weathered rock samples collected at the same field site tended to be unsatisfactory. The outcome of this modelling exercise provides an overview of the present status of adsorption modelling in the context of radionuclide migration as practised in a number of countries worldwide.

Trace gas detection from fermentation processes in apples; an intercomparison study between proton-transfer-reaction mass spectrometry and laser photoacoustics

NASA Astrophysics Data System (ADS)

Boamfa, E. I.; Steeghs, M. M. L.; Cristescu, S. M.; Harren, F. J. M.

2004-12-01

A custom-built proton-transfer-reaction mass spectrometry (PTR-MS) instrument was used to monitor the emission of various compounds (aldehydes, alcohols, acids, acetates and C-6 compounds) related to fermentation, aroma and flavour, released by four apple cultivars (Elstar, Jonaglod, Granny Smith and Pink Lady) under short anaerobic (24 h) and post-anaerobic conditions. The novel feature of our instrument is the new design of the collisional dissociation chamber, which separates the high pressure in the drift tube (2 mbar) from the high vacuum pressure in the detection region (10-6 mbar). The geometry of this chamber was changed and a second turbo pump was added to reduce the influence of collisional loss of ions, background signals and cluster ions, which facilitates the interpretation of the mass spectra and increases the signal intensity at the mass of the original protonated compound. With this system, detection limits of similar magnitude to the ones reported in literature are reached. An intercomparison study between PTR-MS and a CO laser-based photoacoustic trace gas detector is presented. The alcoholic fermentation products (acetaldehyde and ethanol) from young rice plants were simultaneously monitored by both methods. A very good agreement was observed for acetaldehyde production. The photoacoustic detector showed about two times lower ethanol concentration as compared to PTR-MS, caused by memory effects due to sticking of compounds to the walls of the nylon tube used to transport the trace gases to the detector.

Laboratory-based versus non-laboratory-based method for assessment of cardiovascular disease risk: the NHANES I Follow-up Study cohort

PubMed Central

Gaziano, Thomas A; Young, Cynthia R; Fitzmaurice, Garrett; Atwood, Sidney; Gaziano, J Michael

2008-01-01

Summary Background Around 80% of all cardiovascular deaths occur in developing countries. Assessment of those patients at high risk is an important strategy for prevention. Since developing countries have limited resources for prevention strategies that require laboratory testing, we assessed if a risk prediction method that did not require any laboratory tests could be as accurate as one requiring laboratory information. Methods The National Health and Nutrition Examination Survey (NHANES) was a prospective cohort study of 14 407 US participants aged between 25–74 years at the time they were first examined (between 1971 and 1975). Our follow-up study population included participants with complete information on these surveys who did not report a history of cardiovascular disease (myocardial infarction, heart failure, stroke, angina) or cancer, yielding an analysis dataset N=6186. We compared how well either method could predict first-time fatal and non-fatal cardiovascular disease events in this cohort. For the laboratory-based model, which required blood testing, we used standard risk factors to assess risk of cardiovascular disease: age, systolic blood pressure, smoking status, total cholesterol, reported diabetes status, and current treatment for hypertension. For the non-laboratory-based model, we substituted body-mass index for cholesterol. Findings In the cohort of 6186, there were 1529 first-time cardiovascular events and 578 (38%) deaths due to cardiovascular disease over 21 years. In women, the laboratory-based model was useful for predicting events, with a c statistic of 0·829. The c statistic of the non-laboratory-based model was 0·831. In men, the results were similar (0·784 for the laboratory-based model and 0·783 for the non-laboratory-based model). Results were similar between the laboratory-based and non-laboratory-based models in both men and women when restricted to fatal events only. Interpretation A method that uses non-laboratory

The fourth radiation transfer model intercomparison (RAMI-IV): Proficiency testing of canopy reflectance models with ISO-13528

NASA Astrophysics Data System (ADS)

Widlowski, J.-L.; Pinty, B.; Lopatka, M.; Atzberger, C.; Buzica, D.; Chelle, M.; Disney, M.; Gastellu-Etchegorry, J.-P.; Gerboles, M.; Gobron, N.; Grau, E.; Huang, H.; Kallel, A.; Kobayashi, H.; Lewis, P. E.; Qin, W.; Schlerf, M.; Stuckens, J.; Xie, D.

2013-07-01

The radiation transfer model intercomparison (RAMI) activity aims at assessing the reliability of physics-based radiative transfer (RT) models under controlled experimental conditions. RAMI focuses on computer simulation models that mimic the interactions of radiation with plant canopies. These models are increasingly used in the development of satellite retrieval algorithms for terrestrial essential climate variables (ECVs). Rather than applying ad hoc performance metrics, RAMI-IV makes use of existing ISO standards to enhance the rigor of its protocols evaluating the quality of RT models. ISO-13528 was developed "to determine the performance of individual laboratories for specific tests or measurements." More specifically, it aims to guarantee that measurement results fall within specified tolerance criteria from a known reference. Of particular interest to RAMI is that ISO-13528 provides guidelines for comparisons where the true value of the target quantity is unknown. In those cases, "truth" must be replaced by a reliable "conventional reference value" to enable absolute performance tests. This contribution will show, for the first time, how the ISO-13528 standard developed by the chemical and physical measurement communities can be applied to proficiency testing of computer simulation models. Step by step, the pre-screening of data, the identification of reference solutions, and the choice of proficiency statistics will be discussed and illustrated with simulation results from the RAMI-IV "abstract canopy" scenarios. Detailed performance statistics of the participating RT models will be provided and the role of the accuracy of the reference solutions as well as the choice of the tolerance criteria will be highlighted.

Variability of creatinine measurements in clinical laboratories: results from the CRIC study.

PubMed

Joffe, Marshall; Hsu, Chi-yuan; Feldman, Harold I; Weir, Matthew; Landis, J R; Hamm, L Lee

2010-01-01

Estimating equations using serum creatinine (SCr) are often used to assess glomerular filtration rate (GFR). Such creatinine (Cr)-based formulae may produce biased estimates of GFR when using Cr measurements that have not been calibrated to reference laboratories. In this paper, we sought to examine the degree of this variation in Cr assays in several laboratories associated with academic medical centers affiliated with the Chronic Renal Insufficiency Cohort (CRIC) Study; to consider how best to correct for this variation, and to quantify the impact of such corrections on eligibility for participation in CRIC. Variability of Cr is of particular concern in the conduct of CRIC, a large multicenter study of subjects with chronic renal disease, because eligibility for the study depends on Cr-based assessment of GFR. A library of 5 large volume plasma specimens from apheresis patients was assembled, representing levels of plasma Cr from 0.8 to 2.4 mg/dl. Samples from this library were used for measurement of Cr at each of the 14 CRIC laboratories repetitively over time. We used graphical displays and linear regression methods to examine the variability in Cr, and used linear regression to develop calibration equations. We also examined the impact of the various calibration equations on the proportion of subjects screened as potential participants who were actually eligible for the study. There was substantial variability in Cr assays across laboratories and over time. We developed calibration equations for each laboratory; these equations varied substantially among laboratories and somewhat over time in some laboratories. The laboratory site contributed the most to variability (51% of the variance unexplained by the specimen) and variation with time accounted for another 15%. In some laboratories, calibration equations resulted in differences in eligibility for CRIC of as much as 20%. The substantial variability in SCr assays across laboratories necessitates calibration

Field intercomparison of a novel optical sensor for formaldehyde quantification

NASA Astrophysics Data System (ADS)

Friedfeld, Stephen; Fraser, Matthew; Lancaster, David; Leleux, Darrin; Rehle, Dirk; Tittel, Frank

2000-08-01

A one-week in situ intercomparison campaign was completed on the Rice University campus for measuring HCHO using three different techniques, including a novel optical sensor based on difference frequency generation (DFG) operating at room temperature. Two chemical derivatization methods, 2,4-dinitrophenylhydrazine (DNPH) and o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA), were deployed during the daylight hours for three- to four-hour time-integrated samples. A real-time optical sensor based on laser absorption spectroscopy was operated simultaneously, including nighttime hours. This tunable spectroscopic source based on difference frequency mixing of two fiber-amplified diode lasers in periodically poled LiNbO3 (PPLN) was operated at 3.5315 µm (2831.64 cm-1) to access a strong HCHO ro-vibrational transition free of interferences from other species. The results showed a bias of -1.7 and -1.2 ppbv and a gross error of 2.6 and 1.5 ppbv for DNPH and PFBHA measurements, respectively, compared with DFG measurements. These results validate the DFG sensor for time-resolved measurements of HCHO in urban areas.

Field intercomparison of a novel optical sensor for formaldehyde quantification

NASA Technical Reports Server (NTRS)

Friedfeld, S.; Fraser, M.; Lancaster, D.; Leleux, D.; Rehle, D.; Tittel, F.

2000-01-01

A one-week in situ intercomparison campaign was completed on the Rice University campus for measuring HCHO using three different techniques, including a novel optical sensor based on difference frequency generation (DFG) operating at room temperature. Two chemical derivatization methods, 2,4-dinitrophenylhydrazine (DNPH) and o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA), were deployed during the daylight hours for three- to four-hour time-integrated samples. A real-time optical sensor based on laser absorption spectroscopy was operated simultaneously, including nighttime hours. This tunable spectroscopic source based on difference frequency mixing of two fiber-amplified diode lasers in periodically poled LiNb03 (PPLN) was operated at 3.5315 micrometers (2831.64 cm 1) to access a strong HCHO ro-vibrational transition free of interferences from other species. The results showed a bias of -1.7 and -1.2 ppbv and a gross error of 2.6 and 1.5 ppbv for DNPH and PFBHA measurements, respectively, compared with DFG measurements. These results validate the DFG sensor for time-resolved measurements of HCHO in urban areas.

Intercomparison of wind speeds inferred by the SASS, altimeter, and SMMR

NASA Technical Reports Server (NTRS)

Wentz, F. J.; Cardone, V. J.; Fedor, L. S.

1982-01-01

The operational theory, control algorithms, and comparisons with surface-determined wind speeds for the scatterometer (SASS), altimeter (ALT), and passive microwave radiometer (SMMR) on board the Seasat satellite are presented. Radiative scattering combining specular reflections and Bragg resonance scattering are noted to occur at tilting waves and sea foam, two conditions highly correlated with wind speed. SASS scans swaths of 70, 200, and 700 km from nadir, the SMMR covers a 150 km strip. Normalized radar sections are derived from the SASS and ALT telemetry, and brightness temperature from the SMMR. ALT winds were found to be biased about 3 m/sec low, while intercomparison between the SMMR and SASS data showed a mean difference of 0.3 m/sec with a standard deviation from measured winds of 1.7 m/sec or less. The effects of land thermal emissions, rain, and sun glint are discussed, and good viewing conditions are concluded to result in 2 m/sec accuracy.

A comprehensive laboratory study on the immersion freezing behavior of illite NX particles: a comparison of 17 ice nucleation measurement techniques

NASA Astrophysics Data System (ADS)

Hiranuma, N.; Augustin-Bauditz, S.; Bingemer, H.; Budke, C.; Curtius, J.; Danielczok, A.; Diehl, K.; Dreischmeier, K.; Ebert, M.; Frank, F.; Hoffmann, N.; Kandler, K.; Kiselev, A.; Koop, T.; Leisner, T.; Möhler, O.; Nillius, B.; Peckhaus, A.; Rose, D.; Weinbruch, S.; Wex, H.; Boose, Y.; DeMott, P. J.; Hader, J. D.; Hill, T. C. J.; Kanji, Z. A.; Kulkarni, G.; Levin, E. J. T.; McCluskey, C. S.; Murakami, M.; Murray, B. J.; Niedermeier, D.; Petters, M. D.; O'Sullivan, D.; Saito, A.; Schill, G. P.; Tajiri, T.; Tolbert, M. A.; Welti, A.; Whale, T. F.; Wright, T. P.; Yamashita, K.

2015-03-01

Immersion freezing is the most relevant heterogeneous ice nucleation mechanism through which ice crystals are formed in mixed-phase clouds. In recent years, an increasing number of laboratory experiments utilizing a variety of instruments have examined immersion freezing activity of atmospherically relevant ice-nucleating particles. However, an intercomparison of these laboratory results is a difficult task because investigators have used different ice nucleation (IN) measurement methods to produce these results. A remaining challenge is to explore the sensitivity and accuracy of these techniques and to understand how the IN results are potentially influenced or biased by experimental parameters associated with these techniques. Within the framework of INUIT (Ice Nuclei Research Unit), we distributed an illite-rich sample (illite NX) as a representative surrogate for atmospheric mineral dust particles to investigators to perform immersion freezing experiments using different IN measurement methods and to obtain IN data as a function of particle concentration, temperature (T), cooling rate and nucleation time. A total of 17 measurement methods were involved in the data intercomparison. Experiments with seven instruments started with the test sample pre-suspended in water before cooling, while 10 other instruments employed water vapor condensation onto dry-dispersed particles followed by immersion freezing. The resulting comprehensive immersion freezing data set was evaluated using the ice nucleation active surface-site density, ns, to develop a representative ns(T) spectrum that spans a wide temperature range (-37 °C < T < -11 °C) and covers 9 orders of magnitude in ns. In general, the 17 immersion freezing measurement techniques deviate, within a range of about 8 °C in terms of temperature, by 3 orders of magnitude with respect to ns. In addition, we show evidence that the immersion freezing efficiency expressed in ns of illite NX particles is relatively

A comprehensive laboratory study on the immersion freezing behavior of illite NX particles. A comparison of 17 ice nucleation measurement techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiranuma, Naruki; Augustin-Bauditz, Stefanie; Bingemer, Heinz

Immersion freezing is the most relevant heterogeneous ice nucleation mechanism through which ice crystals are formed in mixed-phase clouds. In recent years, an increasing number of laboratory experiments utilizing a variety of instruments have examined immersion freezing activity of atmospherically relevant ice-nucleating particles. However, an intercomparison of these laboratory results is a difficult task because investigators have used different ice nucleation (IN) measurement methods to produce these results. A remaining challenge is to explore the sensitivity and accuracy of these techniques and to understand how the IN results are potentially influenced or biased by experimental parameters associated with these techniques.more » Within the framework of INUIT (Ice Nuclei Research Unit), we distributed an illite-rich sample (illite NX) as a representative surrogate for atmospheric mineral dust particles to investigators to perform immersion freezing experiments using different IN measurement methods and to obtain IN data as a function of particle concentration, temperature ( T), cooling rate and nucleation time. A total of 17 measurement methods were involved in the data intercomparison. Experiments with seven instruments started with the test sample pre-suspended in water before cooling, while 10 other instruments employed water vapor condensation onto dry-dispersed particles followed by immersion freezing. The resulting comprehensive immersion freezing data set was evaluated using the ice nucleation active surface-site density, n s, to develop a representative n s( T) spectrum that spans a wide temperature range (-37 °C < T < -11 °C) and covers 9 orders of magnitude in n s. In general, the 17 immersion freezing measurement techniques deviate, within a range of about 8 °C in terms of temperature, by 3 orders of magnitude with respect to n s. In addition, we show evidence that the immersion freezing efficiency expressed in n s of illite NX particles is

A comprehensive laboratory study on the immersion freezing behavior of illite NX particles. A comparison of 17 ice nucleation measurement techniques

DOE PAGES

Hiranuma, Naruki; Augustin-Bauditz, Stefanie; Bingemer, Heinz; ...

2015-03-06

Immersion freezing is the most relevant heterogeneous ice nucleation mechanism through which ice crystals are formed in mixed-phase clouds. In recent years, an increasing number of laboratory experiments utilizing a variety of instruments have examined immersion freezing activity of atmospherically relevant ice-nucleating particles. However, an intercomparison of these laboratory results is a difficult task because investigators have used different ice nucleation (IN) measurement methods to produce these results. A remaining challenge is to explore the sensitivity and accuracy of these techniques and to understand how the IN results are potentially influenced or biased by experimental parameters associated with these techniques.more » Within the framework of INUIT (Ice Nuclei Research Unit), we distributed an illite-rich sample (illite NX) as a representative surrogate for atmospheric mineral dust particles to investigators to perform immersion freezing experiments using different IN measurement methods and to obtain IN data as a function of particle concentration, temperature ( T), cooling rate and nucleation time. A total of 17 measurement methods were involved in the data intercomparison. Experiments with seven instruments started with the test sample pre-suspended in water before cooling, while 10 other instruments employed water vapor condensation onto dry-dispersed particles followed by immersion freezing. The resulting comprehensive immersion freezing data set was evaluated using the ice nucleation active surface-site density, n s, to develop a representative n s( T) spectrum that spans a wide temperature range (-37 °C < T < -11 °C) and covers 9 orders of magnitude in n s. In general, the 17 immersion freezing measurement techniques deviate, within a range of about 8 °C in terms of temperature, by 3 orders of magnitude with respect to n s. In addition, we show evidence that the immersion freezing efficiency expressed in n s of illite NX particles is

An intercomparison of observational precipitation data sets over Northwest India during winter

NASA Astrophysics Data System (ADS)

Nageswararao, M. M.; Mohanty, U. C.; Ramakrishna, S. S. V. S.; Dimri, A. P.

2018-04-01

Winter (DJF) precipitation over Northwest India (NWI) is very important for the cultivation of Rabi crops. Thus, an accurate estimation of high-resolution observations, evaluation of high-resolution numerical models, and understanding the local variability trends are essential. The objective of this study is to verify the quality of a new high spatial resolution (0.25° × 0.25°) gridded daily precipitation data set of India Meteorological Department (IMD1) over NWI during winter. An intercomparison with four existing precipitation data sets at 0.5° × 0.5° of IMD (IMD2), 1° × 1° of IMD (IMD3), 0.25° × 0.25° of APHRODITE (APRD1), and 0.5° × 0.5° of APHRODITE (APRD1) resolution during a common period of 1971-2003 is done. The evaluation of data quality of these five data sets against available 26 station observations is carried out, and the results clearly indicate that all the five data sets reasonably agreed with the station observation. However, the errors are relatively more in all the five data sets over Jammu and Kashmir-related four stations (Srinagar, Drass, Banihal top, and Dawar), while these errors are less in the other stations. It may be due to the lack of station observations over the region. The quality of IMD1 data set over NWI for winter precipitation is reasonably well than the other data sets. The intercomparison analysis suggests that the climatological mean, interannual variability, and coefficient of variation from IMD1 are similar with other data sets. Further, the analysis extended to the India meteorological subdivisions over the region. This analysis indicates overestimation in IMD3 and underestimation in APRD1 and APRD2 over Jammu and Kashmir, Himachal Pradesh, and NWI as a whole, whereas IMD2 is closer to IMD1. Moreover, all the five data sets are highly correlated (>0.5) among them at 99.9% confidence level for all subdivisions. It is remarkably noticed that multicategorical (light precipitation, moderate precipitation, heavy

An intercomparison of longwave measurements by ERBE radiometers on the NOAA-9 and ERBS satellites

NASA Technical Reports Server (NTRS)

House, Frederick B.

1989-01-01

Two instrument modules of each satellite on which the Earth Radiation Budget Experiment (ERBE) is orbiting observe components of the earth radiation budget with three different scales of earth view. An intercomparison of longwave measurements by these instruments provides relative information concerning radiometric performance at satellite altitude, techniques of estimating upwelling exitances, and an end-to-end evaluation of the data processing system. Results indicate that the ERBE radiometers are mildly sensitive to varying thermal loads from the spacecraft and/or the earth-space environment. Radiometric variations at the satellite and methods of data interpretation contribute about equally to the uncertainty of radiant exitances from the earth.

Going GLP: Conducting Toxicology Studies in Compliance with Good Laboratory Practices.

PubMed

Carroll, Erica Eggers

2016-01-01

Good laboratory practice standards are US federal regulations enacted as part of the Federal Insecticide, Fungicide, and Rodenticide Act (40 CFR Part 160), the Toxic Substance Control Act (40 CFR Part 792), and the Good Laboratory Practice for Nonclinical Laboratory Studies (21 CFR Part 58) to support protection of public health in the areas of pesticides, chemicals, and drug investigations in response to allegations of inaccurate data acquisition. Essentially, good laboratory practices (GLPs) are a system of management controls for nonclinical research studies involving animals to ensure the uniformity, consistency, reliability, reproducibility, quality, and integrity of data collected as part of chemical (including pharmaceuticals) tests, from in vitro through acute to chronic toxicity tests. The GLPs were established in the United States in 1978 as a result of the Industrial Bio-Test Laboratory scandal which led to congressional hearings and actions to prevent fraudulent data reporting and collection. Although the establishment of infrastructure for GLPs compliance is labor-intensive and time-consuming, achievement and maintenance of GLP compliance ensures the accuracy of the data collected from each study, which is critical for defending results, advancing science, and protecting human and animal health. This article describes how and why those in the US Army Medical Department responsible for protecting the public health of US Army and other military personnel made the policy decision to have its toxicology laboratory achieve complete compliance with GLP standards, the first such among US Army laboratories. The challenges faced and how they were overcome are detailed.

Comparing apples and oranges: the Community Intercomparison Suite

NASA Astrophysics Data System (ADS)

Schutgens, Nick; Stier, Philip; Kershaw, Philip; Pascoe, Stephen

2015-04-01

Visual representation and comparison of geoscientific datasets presents a huge challenge due to the large variety of file formats and spatio-temporal sampling of data (be they observations or simulations). The Community Intercomparison Suite attempts to greatly simplify these tasks for users by offering an intelligent but simple command line tool for visualisation and colocation of diverse datasets. In addition, CIS can subset and aggregate large datasets into smaller more manageable datasets. Our philosophy is to remove as much as possible the need for specialist knowledge by the user of the structure of a dataset. The colocation of observations with model data is as simple as: "cis col ::" which will resample the simulation data to the spatio-temporal sampling of the observations, contingent on a few user-defined options that specify a resampling kernel. As an example, we apply CIS to a case study of biomass burning aerosol from the Congo. Remote sensing observations, in-situe observations and model data are shown in various plots, with the purpose of either comparing different datasets or integrating them into a single comprehensive picture. CIS can deal with both gridded and ungridded datasets of 2, 3 or 4 spatio-temporal dimensions. It can handle different spatial coordinates (e.g. longitude or distance, altitude or pressure level). CIS supports both HDF, netCDF and ASCII file formats. The suite is written in Python with entirely publicly available open source dependencies. Plug-ins allow a high degree of user-moddability. A web-based developer hub includes a manual and simple examples. CIS is developed as open source code by a specialist IT company under supervision of scientists from the University of Oxford and the Centre of Environmental Data Archival as part of investment in the JASMIN superdatacluster facility.

Intercomparison of open-path trace gas measurements with two dual-frequency-comb spectrometers

DOE PAGES

Waxman, Eleanor M.; Cossel, Kevin C.; Truong, Gar-Wing; ...

2017-09-11

We present the first quantitative intercomparison between two open-path dual-comb spectroscopy (DCS) instruments which were operated across adjacent 2 km open-air paths over a 2-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6023 to 6376 cm −1 (1568 to 1660 nm), corresponding to a 355 cm −1 bandwidth, at 0.0067 cm −1 sample spacing. The measured absorption spectra agree with each other to within 5 × 10 −4 in absorbance without any external calibration of either instrument. The absorption spectra are fit to retrieve path-integrated concentrations for carbon dioxide (CO 2), methane (CH 4), water (H 2O), and deuteratedmore » water (HDO). The retrieved dry mole fractions agree to 0.14 % (0.57 ppm) for CO 2, 0.35 % (7 ppb) for CH 4, and 0.40 % (36 ppm) for H 2O at  ∼  30 s integration time over the 2-week measurement campaign, which included 24 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a World Meteorological Organization (WMO)-calibrated cavity ring-down point sensor located along the path with good agreement. Short-term and long-term differences between the open-path DCS and point sensor are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the 2-week measurement campaign yields diurnal cycles of CO 2 and CH 4 that are consistent with the presence of local sources of CO 2 and absence of local sources of CH 4.« less

Intercomparison of open-path trace gas measurements with two dual-frequency-comb spectrometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waxman, Eleanor M.; Cossel, Kevin C.; Truong, Gar-Wing

We present the first quantitative intercomparison between two open-path dual-comb spectroscopy (DCS) instruments which were operated across adjacent 2 km open-air paths over a 2-week period. We used DCS to measure the atmospheric absorption spectrum in the near infrared from 6023 to 6376 cm −1 (1568 to 1660 nm), corresponding to a 355 cm −1 bandwidth, at 0.0067 cm −1 sample spacing. The measured absorption spectra agree with each other to within 5 × 10 −4 in absorbance without any external calibration of either instrument. The absorption spectra are fit to retrieve path-integrated concentrations for carbon dioxide (CO 2), methane (CH 4), water (H 2O), and deuteratedmore » water (HDO). The retrieved dry mole fractions agree to 0.14 % (0.57 ppm) for CO 2, 0.35 % (7 ppb) for CH 4, and 0.40 % (36 ppm) for H 2O at  ∼  30 s integration time over the 2-week measurement campaign, which included 24 °C outdoor temperature variations and periods of strong atmospheric turbulence. This agreement is at least an order of magnitude better than conventional active-source open-path instrument intercomparisons and is particularly relevant to future regional flux measurements as it allows accurate comparisons of open-path DCS data across locations and time. We additionally compare the open-path DCS retrievals to a World Meteorological Organization (WMO)-calibrated cavity ring-down point sensor located along the path with good agreement. Short-term and long-term differences between the open-path DCS and point sensor are attributed, respectively, to spatial sampling discrepancies and to inaccuracies in the current spectral database used to fit the DCS data. Finally, the 2-week measurement campaign yields diurnal cycles of CO 2 and CH 4 that are consistent with the presence of local sources of CO 2 and absence of local sources of CH 4.« less

The Dynamical Core Model Intercomparison Project (DCMIP-2016): Results of the Supercell Test Case

NASA Astrophysics Data System (ADS)

Zarzycki, C. M.; Reed, K. A.; Jablonowski, C.; Ullrich, P. A.; Kent, J.; Lauritzen, P. H.; Nair, R. D.

2016-12-01

The 2016 Dynamical Core Model Intercomparison Project (DCMIP-2016) assesses the modeling techniques for global climate and weather models and was recently held at the National Center for Atmospheric Research (NCAR) in conjunction with a two-week summer school. Over 12 different international modeling groups participated in DCMIP-2016 and focused on the evaluation of the newest non-hydrostatic dynamical core designs for future high-resolution weather and climate models. The paper highlights the results of the third DCMIP-2016 test case, which is an idealized supercell storm on a reduced-radius Earth. The supercell storm test permits the study of a non-hydrostatic moist flow field with strong vertical velocities and associated precipitation. This test assesses the behavior of global modeling systems at extremely high spatial resolution and is used in the development of next-generation numerical weather prediction capabilities. In this regime the effective grid spacing is very similar to the horizontal scale of convective plumes, emphasizing resolved non-hydrostatic dynamics. The supercell test case sheds light on the physics-dynamics interplay and highlights the impact of diffusion on model solutions.

Semiconductor laser joint study program with Rome Laboratory

NASA Astrophysics Data System (ADS)

Schaff, William J.; Okeefe, Sean S.; Eastman, Lester F.

1994-09-01

A program to jointly study vertical-cavity surface emitting lasers (VCSEL) for high speed vertical optical interconnects (VOI) has been conducted under an ES&E between Rome Laboratory and Cornell University. Lasers were designed, grown, and fabricated at Cornell University. A VCSEL measurement laboratory has been designed, built, and utilized at Rome Laboratory. High quality VCSEL material was grown and characterized by fabricating conventional lateral cavity lasers that emitted at the design wavelength of 1.04 microns. The VCSEL's emit at 1.06 microns. Threshold currents of 16 mA at 4.8 volts were obtained for 30 microns diameter devices. Output powers of 5 mW were measured. This is 500 times higher power than from the light emitting diodes employed previously for vertical optical interconnects. A new form of compositional grading using a cosinusoidal function has been developed and is very successful for reducing diode series resistance for high speed interconnection applications. A flip-chip diamond package compatible with high speed operation of 16 VCSEL elements has been designed and characterized. A flip-chip device binding effort at Rome Laboratory was also designed and initiated. This report presents details of the one-year effort, including process recipes and results.

Intercomparison of General Circulation Models for Hot Extrasolar Planet Atmospheres

NASA Astrophysics Data System (ADS)

Cho, James

2013-11-01

In this collaborative work with I. Polichtchouk, C. Watkins, H. Th. Thrastarson, O. M. Umurhan, and M. de la Torre-Juárez, we compare five general circulation models (GCMs) which have been recently used to study hot extrasolar planet atmospheres (BOB, CAM, IGCM, MITgcm, and PEQMOD), under three test cases useful for assessing model convergence and accuracy. Such a broad, detailed intercomparison has not been performed thus far for extrasolar planets study. The models considered all solve the traditional primitive equations, but employ different numerical algorithms or grids (e.g., pseudospectral and finite volume, with the latter separately in longitude-latitude and ``cubed-sphere'' grids). The test cases are chosen to cleanly address specific aspects of the behaviors typically reported in hot extrasolar planet simulations: 1) steady-state, 2) nonlinearly evolving baroclinic wave, and 3) response to fast timescale thermal relaxation. When initialized with a steady jet, all models maintain the steadiness, as they should--except MITgcm in cubed-sphere grid. A very good agreement is obtained for a baroclinic wave evolving from an initial instability in spectral models (only). However, exact numerical convergence is still not achieved across the spectral models: amplitudes and phases are observably different. When subject to a typical ``hot-Jupiter''-like forcing, all five models show quantitatively different behavior--although qualitatively similar, time-variable, quadrupole-dominated flows are produced. Hence, as have been advocated in several past studies, specific quantitative predictions (such as the location of large vortices and hot regions) by GCMs should be viewed with caution. Overall, in the tests considered here, spectral models in pressure coordinate (PEBOB and PEQMOD) perform the best and MITgcm in cubed-sphere grid performs the worst. This work has been supported by the Science and Technology Facilities Council, Westfield Small Grant, NASA Postdoctoral

An Exploratory Study of Objective Attainment in the Divergent Physics Laboratory.

ERIC Educational Resources Information Center

Lerch, Robert Donald

Students enrolled in the introductory physics laboratory at New Mexico State University participated in this study. A stated set of objectives, developed by Dr. John M. Fowler of the Commission on College Physics, was used in the laboratory. This study attempted to measure student achievement based on the use of these objectives as opposed to the…

KEY COMPARISON: CCEM.RF-K18.CL (GT-RF/00-1): Noise in 50 Ω coaxial line at frequencies up to 1 GHz

NASA Astrophysics Data System (ADS)

Eiø, Christopher; Adamson, David; Randa, James; Allal, Djamel; Uzdin, Rinadij

2006-01-01

A measurement comparison of noise temperature has been carried out between four national metrology laboratories in coaxial line at 30 MHz, 60 MHz and 1 GHz. The identification of this intercomparison is CCEM.RF-K18.CL. Two noise sources have been measured. The following four national laboratories participated in this intercomparison: NPL (United Kingdom), NIST (United States of America), BNM-LNE (France) and VNIIFTRI (Russia). The National Physical Laboratory (UK) acted as the pilot laboratory for the comparison. It can be seen that there is generally good agreement between the laboratories. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

An intercomparison for NIRS and NYU passive thoron gas detectors at NYU.

PubMed

Sorimachi, Atsuyuki; Ishikawa, Tetsuo; Tokonami, Shinji; Chittaporn, Passaporn; Harley, Naomi H

2012-04-01

An intercomparison on thoron ((220)Rn) measurement was carried out between National Institute of Radiological Sciences, Japan (NIRS), and New York University School of Medicine, USA (NYU). The measurements of (220)Rn concentration at NIRS and NYU were performed by using the scintillation cell method and the two-filter method, respectively, as the standard measurement method. Three types of alpha track detectors based on passive radon ((222)Rn)-(220)Rn discriminative measurement technique were used: Raduet and Radopot detectors were used at NIRS, and four-leaf detectors were used at NYU. In this study, the authors evaluated (220)Rn concentration variation in terms of run for exposure, measurement method, and exposure chamber. The detectors were exposed to (220)Rn gas with approximately 15 kBq m(-3) during the period from 0.75 to 3 d. As a result, the variation of each measurement method among these exposure runs was comparable to or less than that for the two-filter method. Agreement between the standard measurement methods of NIRS and NYU was observed to be about 10%, as is the case with the passive detectors. The Raduet detector showed a large variation in the detection response between the NIRS and NYU chambers, which could be related to different traceability.

Intercomparison of Carbonate Deposits on Mars: VNIR Spectral Character and Geologic Context

NASA Astrophysics Data System (ADS)

Wiseman, S.; Mustard, J. F.; Ehlmann, B. L.

2012-12-01

Carbonate-bearing deposits were identified on Mars at multiple locations using CRISM VNIR spectral data [1,2,3,4,5]. Carbonates exhibit distinctive C-O related absorption features near 2300, 2500, 3400 and 3900nm that can be used to identify specific carbonate phases (e.g., Mg-carbonates have band minima at 2300/2500nm and Fe-carbonates have minima at 2330/2530nm [6]). The features at 2300 and 2500nm are the focus of most CRISM analyses because this part of the spectral range is well calibrated, lacks strong contributions from thermal emission, and is not impacted by strong water-related absorptions near 3000nm (e.g., in Fe/Mg phyllosilicates). However, multiple other phases also exhibit features near 2300 and 2500nm.For carbonates, the depth of the 2500nm feature is stronger than at 2300nm as opposed to most Fe/Mg phyllosilicates. Mixing of the carbonate with other phases in CRISM pixels impacts the band centers and strengths of the 2300 and 2500nm features and therefore complicates identification of the carbonate phase(s) responsible for observed CRISM spectral features. In this study we analyze CRISM data fully corrected for the atmosphere using DISORT radiative transfer modeling [7,8] to evaluate CRISM spectra of multiple carbonate-bearing deposits. Rigorous intercomparison of CRISM spectra extracted from different images is affected by variable aerosol, CO2 and water vapor features left by the standard volcano scan empirical atmospheric correction [9]. While residual gas absorptions are commonly suppressed by ratioing, the appearance of spectral features in ratio spectra is impacted by spectral features in the dominator spectrum compromising detailed assessments of ratio spectra derived from different images. Atmospheric correction is particularly important for interpreting carbonate deposits because the 2500nm carbonate feature overlaps with atmospheric water vapor absorptions. In Nili Fossae, carbonates occur in association with olivine, smectite, serpentine

Goddard Laboratory for Atmospheric Sciences physical retrieval system for remote determination of weather and climate parameter from HIRS2 and MSU observations

NASA Technical Reports Server (NTRS)

Susskind, J.

1984-01-01

At the Goddard Laboratory for Atmospheric Sciences (GLAS) a physically based satellite temperature sounding retrieval system, involving the simultaneous analysis of HIRS2 and MSU sounding data, was developed for determining atmospheric and surface conditions which are consistent with the observed radiances. In addition to determining accurate atmospheric temperature profiles even in the presence of cloud contamination, the system provides global estimates of day and night sea or land surface temperatures, snow and ice cover, and parameters related to cloud cover. Details of the system are described elsewhere. A brief overview of the system is presented, as well as recent improvements and previously unpublished results, relating to the sea-surface intercomparison workshop, the diurnal variation of ground temperatures, and forecast impact tests.

Staffing benchmarks for clinical laboratories: a College of American Pathologists Q-Probes study of laboratory staffing at 98 institutions.

PubMed

Jones, Bruce A; Darcy, Teresa; Souers, Rhona J; Meier, Frederick A

2012-02-01

Publicly available information concerning laboratory staffing benchmarks is scarce. One of the few publications on this topic summarized the findings of a Q-Probes study performed in 2004. This publication reports a similar survey with data collected in 2010. To assess the relationship between staffing levels in specified laboratory sections and test volumes in these sections and quantify management span of control. The study defined 4 laboratory sections: anatomic pathology (including cytology), chemistry/hematology/immunology, microbiology, and transfusion medicine. It divided staff into 3 categories: management, nonmanagement (operational or bench staff), and doctoral (MD, PhD) supervisory staff. People in these categories were tabulated as full-time equivalents and exclusions specified. Tests were counted in uniform formats, specified for each laboratory section, according to Medicare rules for the bundling and unbundling of tests. Ninety-eight participating institutions provided data that showed significant associations between test volumes and staffing for all 4 sections. There was wide variation in productivity based on volume. There was no relationship between testing volume per laboratory section and management span of control. Higher productivity in chemistry/hematology/immunology was associated with a higher fraction of tests coming from nonacute care patients. In both the 2004 and 2010 studies, productivity was inseparably linked to test volume. Higher test volume was associated with higher productivity ratios in chemistry/hematology/immunology and transfusion medicine sections. The impact of various testing services on productivity is section-specific.

Intercomparison of 30+ years of AVHRR and Landsat-5 TM Surface Reflectance using Multiple Pseudo-Invariant Calibration Sites

NASA Astrophysics Data System (ADS)

Santamaría-Artigas, A. E.; Franch, B.; Vermote, E.; Roger, J. C.; Justice, C. O.

2017-12-01

The 30+ years daily surface reflectance long term data record (LTDR) from the Advanced Very High Resolution Radiometer (AVHRR) is a valuable source of information for long-term studies of the Earth surface. This LTDR was generated by combining observations from multiple AVHRR sensors aboard different NOAA satellites starting from the early 1980s, and due to the lack of on-board calibration its quality should be evaluated. Previous studies have used observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) over pseudo-invariant calibration sites (PICS) as a calibrated reference to assess the performance of AVHRR products. However, this limits the evaluation to the period after MODIS launch. In this work, the AVHRR surface reflectance LTDR was evaluated against Landsat-5 Thematic Mapper (TM) data using observations from 4 well known pseudo-invariant calibration sites (i.e. Sonoran, Saharan, Sudan1, and Libya4) over an extended time period (1984-2011). For the intercomparison, AVHRR and TM observations of each site were extracted and averaged over a 20 km x 20 km area and aggregated to monthly mean values. In order to account for the spectral differences between sensors, Hyperion hyperspectral data from the Sonoran and Libya4 sites were convolved with sensor-specific relative spectral responses, and used to compute spectral band adjustment factors (SBAFs). Results of the intercomparison are reported in terms of the root mean square difference (RMSD) and determination coefficient (r2). In general, there is good agreement between the surface reflectance products from both sensors. The overall RMSD and r2 for all the sites and AVHRR/TM combinations were 0.03 and 0.85 for the red band, and 0.04 and 0.81 for the near-infrared band. These results show the strong performance of the AVHRR surface reflectance LTDR through all of the considered period. Thus, remarking its usefulness and value for long term Earth studies. Figure 1 shows the red (filled markers

Intercomparison of Martian Lower Atmosphere Simulated Using Different Planetary Boundary Layer Parameterization Schemes

NASA Technical Reports Server (NTRS)

Natarajan, Murali; Fairlie, T. Duncan; Dwyer Cianciolo, Alicia; Smith, Michael D.

2015-01-01

We use the mesoscale modeling capability of Mars Weather Research and Forecasting (MarsWRF) model to study the sensitivity of the simulated Martian lower atmosphere to differences in the parameterization of the planetary boundary layer (PBL). Characterization of the Martian atmosphere and realistic representation of processes such as mixing of tracers like dust depend on how well the model reproduces the evolution of the PBL structure. MarsWRF is based on the NCAR WRF model and it retains some of the PBL schemes available in the earth version. Published studies have examined the performance of different PBL schemes in NCAR WRF with the help of observations. Currently such assessments are not feasible for Martian atmospheric models due to lack of observations. It is of interest though to study the sensitivity of the model to PBL parameterization. Typically, for standard Martian atmospheric simulations, we have used the Medium Range Forecast (MRF) PBL scheme, which considers a correction term to the vertical gradients to incorporate nonlocal effects. For this study, we have also used two other parameterizations, a non-local closure scheme called Yonsei University (YSU) PBL scheme and a turbulent kinetic energy closure scheme called Mellor- Yamada-Janjic (MYJ) PBL scheme. We will present intercomparisons of the near surface temperature profiles, boundary layer heights, and wind obtained from the different simulations. We plan to use available temperature observations from Mini TES instrument onboard the rovers Spirit and Opportunity in evaluating the model results.

A River Model Intercomparison Project in Preparation for SWOT

NASA Astrophysics Data System (ADS)

David, C. H.; Andreadis, K.; Famiglietti, J. S.; Beighley, E.; Boone, A. A.; Yamazaki, D.; Paiva, R. C. D.; Fleischmann, A. S.; Collischonn, W.; Fisher, C. K.; Kim, H.; Biancamaria, S.

2017-12-01

The Surface Water and Ocean Topography (SWOT) mission is currently scheduled to launch at the beginning of next decade. SWOT is expected to retrieve unprecedented measurements of water extent, elevation, and slope in the largest terrestrial water bodies. Such potential transformative information motivates the investigation of our ability to ingest the associated data into continental-scale models of terrestrial hydrology. In preparation for the expected SWOT observations, an inter-comparison of continental-scale river models is being performed. This comparison experiment focuses on four of the world's largest river basins: the Amazon, the Mississippi, the Niger, and the Saint-Lawrence. This ongoing project focuses on two main research questions: 1) How can we best prepare for the expected SWOT continental to global measurements before SWOT even flies?, and 2) What is the added value of including SWOT terrestrial measurements into global hydro models for enhancing our understanding of the terrestrial water cycle and the climate system? We present here the results of the second year of this project which now includes simulations from six numerical models of rivers over the Mississippi and sheds light on the implications of various modeling choices on simulation quality as well as on the potential impact of SWOT observations.

Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy: Method development and intercomparison

NASA Astrophysics Data System (ADS)

Harris, E. J.; Eyer, S.; Mohn, J.; Röckmann, T.; Popa, E.; Lowry, D.; Nisbet, E. G.; Fisher, R. E.; Brennwald, M. S.; Fischer, H.; Emmenegger, L.; Tuzson, B.; Zellweger, C.

2015-12-01

Methane (CH4) is the second most important anthropogenically emitted greenhouse gas after carbon dioxide (CO2). Its mole fraction has increased from around 722 ppb in pre-industrial times to 1824 ppb in 2013 and the anthropogenic fraction is estimated to be 60 % of the total emissions. A promising approach to improve the understanding of the CH4 budget is the use of isotopologues to distinguish between various CH4 source processes. In the presented study in situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, mmole/mole) methane is 0.1‰ and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. [1] Based on replicate measurements of compressed air during a two-week intercomparison campaign, the repeatability of the TREX-QCLAS was determined to be 0.19 ‰ and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to IRMS based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers (Figure). Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX-QCLAS data and bag/flask sampling-IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and

Intercomparison of the measurements of oxalic acid in aerosols by gas chromatography and ion chromatography

NASA Astrophysics Data System (ADS)

Kawamura, Kimitaka; Barrie, Leonard A.; Toom-Sauntry, Desiree

2010-12-01

Oxalate, the anion of oxalic acid, is one of the most abundant measurable organic species in atmospheric aerosols. Traditionally, this bifunctional species has been measured by gas chromatography (GC) after derivatization to butyl ester and by ion chromatography (IC) without derivatization. However, there are few published comparisons of the two techniques. Here, we report the results of an intercomparison study for the measurement of oxalic acid in Arctic aerosols (<2.5 μm, n = 82) collected in 1992 using GC and IC. The concentrations of oxalic acid by GC ranged from 6.5-59.1 ng m -3 (av. 26.0 ng m -3, median 26.2 ng m -3) whereas those by IC ranged from 6.6-52.1 ng m -3 (av. 26.6 ng m -3, median 25.4 ng m -3). They showed a good correlation ( r = 0.84) with a slope of 0.96. Thus, observations of oxalate obtained by GC employing dibutyl esters are almost equal to those by IC. Because the accuracy of oxalic acid by GC method largely depends on the method used, it is important to strictly examine the recovery in each study.

Inter-comparison of Computer Codes for TRISO-based Fuel Micro-Modeling and Performance Assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brian Boer; Chang Keun Jo; Wen Wu

2010-10-01

The Next Generation Nuclear Plant (NGNP), the Deep Burn Pebble Bed Reactor (DB-PBR) and the Deep Burn Prismatic Block Reactor (DB-PMR) are all based on fuels that use TRISO particles as their fundamental constituent. The TRISO particle properties include very high durability in radiation environments, hence the designs reliance on the TRISO to form the principal barrier to radioactive materials release. This durability forms the basis for the selection of this fuel type for applications such as Deep Bun (DB), which require exposures up to four times those expected for light water reactors. It follows that the study and predictionmore » of the durability of TRISO particles must be carried as part of the safety and overall performance characterization of all the designs mentioned above. Such evaluations have been carried out independently by the performers of the DB project using independently developed codes. These codes, PASTA, PISA and COPA, incorporate models for stress analysis on the various layers of the TRISO particle (and of the intervening matrix material for some of them), model for fission products release and migration then accumulation within the SiC layer of the TRISO particle, just next to the layer, models for free oxygen and CO formation and migration to the same location, models for temperature field modeling within the various layers of the TRISO particle and models for the prediction of failure rates. All these models may be either internal to the code or external. This large number of models and the possibility of different constitutive data and model formulations and the possibility of a variety of solution techniques makes it highly unlikely that the model would give identical results in the modeling of identical situations. The purpose of this paper is to present the results of an inter-comparison between the codes and to identify areas of agreement and areas that need reconciliation. The inter-comparison has been carried out by the

Hiero-Dermato-Glyphics: Laboratory Study of the Skin

ERIC Educational Resources Information Center

Roark, Oakley F.

1977-01-01

Explains several laboratory exercises using the skin, including the mapping of receptors, counting of sweat glands, computation of total skin area, comparison of various animal skins, measurement of the palm triradius angle, and study of epidermal ridges (dermatoglyphics) in males and females. (CS)

Laboratory Practices of Beginning Secondary Science Teachers: A Five-Year Study

ERIC Educational Resources Information Center

Wong, Sissy S.; Firestone, Jonah B.; Luft, Julie A.; Weeks, Charles B.

2013-01-01

During the beginning years of teaching, science teachers develop the knowledge and skills needed to design and implement science laboratories. In this regard, this quantitative study focused on the reported laboratory practices of 61 beginning secondary science teachers who participated in four different induction programs. The results…

Cloud Microphysical Properties in Mesoscale Convective Systems: An Intercomparison of Three Tropical Locations

NASA Astrophysics Data System (ADS)

Fontaine, Emmanuel; Leroy, Delphine; Schwarzenboeck, Alfons; Coutris, Pierre; Delanoë, Julien; Protat, Alain; Dezitter, Fabien; Grandin, Alice; Strapp, John W.; Lilie, Lyle E.

2017-04-01

Mesoscale Convective Systems are complex cloud systems which are primarily the result of specific synoptic conditions associated with mesoscale instabilities leading to the development of cumulonimbus type clouds (Houze, 2004). These systems can last several hours and can affect human societies in various ways. In general, weather and climate models use simplistic schemes to describe ice hydrometeors' properties. However, MCS are complex cloud systems where the dynamic, radiative and precipitation processes depend on spatiotemporal location in the MCS (Houze, 2004). As a consequence, hydrometeor growth processes in MCS vary in space and time, thereby impacting shape and concentration of ice crystals and finally CWC. As a consequence, differences in the representation of ice properties in models (Li et al., 2007, 2005) lead to significant disagreements in the quantification of ice cloud effects on climate evolution (Intergovernmental Panel on Climate Change Fourth Assessment Report). An accurate estimation of the spatiotemporal CWC distribution is therefore a key parameter for evaluating and improving numerical weather prediction (Stephens et al., 2002). The main purpose of this study is to show ice microphysical properties of MCS observed in three different locations in the tropical atmosphere: West-African continent, Indian Ocean, and Northern Australia. An intercomparison study is performed in order to quantify how similar or different are the ice hydrometeors' properties in these three regions related to radar reflectivity factors and temperatures observed in respective MCS.

Real-time analysis of δ13C- and δD-CH4 in ambient air with laser spectroscopy: method development and first intercomparison results

NASA Astrophysics Data System (ADS)

Eyer, S.; Tuzson, B.; Popa, M. E.; van der Veen, C.; Röckmann, T.; Rothe, M.; Brand, W. A.; Fisher, R.; Lowry, D.; Nisbet, E. G.; Brennwald, M. S.; Harris, E.; Zellweger, C.; Emmenegger, L.; Fischer, H.; Mohn, J.

2015-08-01

In situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, μmole/mole) methane is 0.1 and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. Based on replicate measurements of compressed air during a two-week intercomparison campaign, the repeatability of the TREX-QCLAS was determined to be 0.19 and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to isotope-ratio mass-spectrometry (IRMS) based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers. Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX-QCLAS data and bag/flask sampling-IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and δD-CH4, respectively. Thus, the intercomparison also reveals the need for reference air samples with accurately determined isotopic composition of CH4 to further improve the interlaboratory compatibility.

Developing Medicare Competitive Bidding: A Study of Clinical Laboratories

PubMed Central

Hoerger, Thomas J.; Meadow, Ann

1997-01-01

Competitive bidding to derive Medicare fees promises several advantages over administered fee systems. The authors show how incentives for cost savings, quality, and access can be incorporated into bidding schemes, and they report on a study of the clinical laboratory industry conducted in preparation for a bidding demonstration. The laboratory industry is marked by variable concentration across geographic markets and, among firms themselves, by social and economic heterogeneity. The authors conclude that these conditions can be accommodated by available bidding design options and by careful selection of bidding markets. PMID:10180003

Inter-comparison of source apportionment of PM10 using PMF and CMB in three sites nearby an industrial area in central Italy

NASA Astrophysics Data System (ADS)

Cesari, Daniela; Donateo, Antonio; Conte, Marianna; Contini, Daniele

2016-12-01

Receptor models (RMs), based on chemical composition of particulate matter (PM), such as Chemical Mass Balance (CMB) and Positive Matrix Factorization (PMF), represent useful tools for determining the impact of PM sources to air quality. This information is useful, especially in areas influenced by anthropogenic activities, to plan mitigation strategies for environmental management. Recent inter-comparison of source apportionment (SA) results showed that one of the difficulties in the comparison of estimated source contributions is the compatibility of the sources, i.e. the chemical profiles of factor/sources used in receptor models. This suggests that SA based on integration of several RMs could give more stable and reliable solutions with respect to a single model. The aim of this work was to perform inter-comparison of PMF (using PMF3.0 and PMF5.0 codes) and CMB outputs, focusing on both source chemical profiles and estimates of source contributions. The dataset included 347 daily PM10 samples collected in three sites in central Italy located near industrial emissions. Samples were chemically analysed for the concentrations of 21 chemical species (NH4+, Ca2 +, Mg2 +, Na+, K+, Mg2 +, SO42 -, NO3-, Cl-, Si, Al, Ti, V, Mn, Fe, Ni, Cu, Zn, Br, EC, and OC) used as input of RMs. The approach identified 9 factor/sources: marine, traffic, resuspended dust, biomass burning, secondary sulphate, secondary nitrate, crustal, coal combustion power plant and harbour-industrial. Results showed that the application of constraints in PMF5.0 improved interpretability of profiles and comparability of estimated source contributions with stoichiometric calculations. The inter-comparison of PMF and CMB gave significant differences for secondary nitrate, biomass burning, and harbour-industrial sources, due to non-compatibility of these source profiles that have local specificities. When these site-dependent specificities were taken into account, optimising the input source profiles of

The HEPEX Seasonal Streamflow Forecast Intercomparison Project

NASA Astrophysics Data System (ADS)

Wood, A. W.; Schepen, A.; Bennett, J.; Mendoza, P. A.; Ramos, M. H.; Wetterhall, F.; Pechlivanidis, I.

2016-12-01

The Hydrologic Ensemble Prediction Experiment (HEPEX; www.hepex.org) has launched an international seasonal streamflow forecasting intercomparison project (SSFIP) with the goal of broadening community knowledge about the strengths and weaknesses of various operational approaches being developed around the world. While some of these approaches have existed for decades (e.g. Ensemble Streamflow Prediction - ESP - in the United States and elsewhere), recent years have seen the proliferation of new operational and experimental streamflow forecasting approaches. These have largely been developed independently in each country, thus it is difficult to assess whether the approaches employed in some centers offer more promise for development than others. This motivates us to establish a forecasting testbed to facilitate a diagnostic evaluation of a range of different streamflow forecasting approaches and their components over a common set of catchments, using a common set of validation methods. Rather than prescribing a set of scientific questions from the outset, we are letting the hindcast results and notable differences in methodologies on a watershed-specific basis motivate more targeted analyses and sub-experiments that may provide useful insights. The initial pilot of the testbed involved two approaches - CSIRO's Bayesian joint probability (BJP) and NCAR's sequential regression - for two catchments, each designated by one of the teams (the Murray River, Australia, and Hungry Horse reservoir drainage area, USA). Additional catchments/approaches are in the process of being added to the testbed. To support this CSIRO and NCAR have developed data and analysis tools, data standards and protocols to formalize the experiment. These include requirements for cross-validation, verification, reference climatologies, and common predictands. This presentation describes the SSFIP experiments, pilot basin results and scientific findings to date.

Laboratory studies of imitation/field studies of tradition: towards a synthesis in animal social learning.

PubMed

Galef, Bennett G

2015-03-01

Here I discuss: (1) historical precedents that have resulted in comparative psychologists accepting the two-action method as the "gold standard" in laboratory investigations of imitation learning, (2) evidence suggesting that the two-action procedure may not be adequate to answer questions concerning the role of imitation in the development of traditional behaviors of animals living in natural habitat, and (3) an alternative approach to the laboratory study of imitation that might increase the relevance of laboratory studies of imitation to the work of behavioral ecologists/primatologists interested in animal traditions and their relationship to human cumulative culture. This article is part of a Special Issue entitled: Tribute to Tom Zentall. Copyright © 2014 Elsevier B.V. All rights reserved.

A Manpower Study of Technical Personnel in Hospital Clinical Laboratories. Final Report.

ERIC Educational Resources Information Center

Harkness, James P., And Others

As one of the efforts related to closing the gap between the growing demands for clinical laboratory workers and the supply of well-trained workers, the volume and quality of laboratory procedures and the general characteristics of workers in North Carolina hospitals were studied. Approaches to the study included tests on "unknowns" by…

Knowledge, attitude, and practice (KAP) of 'teaching laboratory' technicians towards laboratory safety and waste management: a pilot interventional study.

PubMed

El-Gilany, A-H; El-Shaer, S; Khashaba, E; El-Dakroory, S A; Omar, N

2017-06-01

A quasi-experimental study was performed on 20 technicians working in the Faculty of Medicine, Mansoura University, Egypt. The knowledge, attitude, and practice (KAP) of laboratory technicians was measured before and two months after enrolling them in an intervention programme about laboratory best practice procedures. The programme addressed laboratory safety and medical waste management. The assessment was performed using a validated Arabic self-administered questionnaire. Pre- and post-intervention scores were compared using non-parametric tests. There are significant increases in the scores of KAP after implementation of the training programme. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

[Tuberculosis Laboratory Surveillance Network (TuLSA) study group. The first step for national tuberculosis laboratory surveillance: Ankara, 2011].

PubMed

Sezen, Figen; Albayrak, Nurhan; Özkara, Şeref; Karagöz, Alper; Alp, Alpaslan; Duyar Ağca, Filiz; İnan Süer, Asiye; Müderris, Tuba; Ceyhan, İsmail; Durmaz, Rıza; Ertek, Mustafa

2015-04-01

The most effective method for monitoring country-level drug resistance frequency and to implement the necessary control measures is the establishment of a laboratory-based surveillance system. The aim of this study was to summarize the follow up trend of the drug-resistant tuberculosis (TB) cases, determine the load of resistance and evaluate the capacities of laboratories depending on laboratory quality assurance system for the installation work of National Tuberculosis Laboratory Surveillance Network (TuLSA) which has started in Ankara in 2011. TuLSA studies was carried out under the coordination of National Tuberculosis Reference Laboratory (NRL) with the participation of TB laboratories and dispensaries. Specimens of TB patients, reported from health institutions, were followed in TB laboratories, and the epidemiological information was collected from the dispensaries. One isolate per patient with the drug susceptibility test (DST) results were sent to NRL from TB laboratories and in NRL the isolates were rechecked with the genotypical (MTBDRplus, Hain Lifescience, Germany) and phenotypical (MGIT 960, BD, USA) DST methods. Molecular epidemiological analysis were also performed by spoligotyping and MIRU/VNTR. Second-line DST was applied to the isolates resistant to rifampin. A total of 1276 patients were reported between January 1st to December 31th 2011, and 335 cases were defined as "pulmonary TB from Ankara province". The mean age of those patients was 43.4 ± 20 years, and 67.5% were male. Three hundred seventeen (94.6%) patients were identified as new cases. The average sample number obtained from pulmonary TB cases was 3.26 ± 2.88, and 229 (68.3%) of them was culture positive. DST was applied to all culture positive isolates; 90.4% (207/229) of cases were susceptible to the five drugs tested (ethambutol, isoniazid, pyrazinamide, rifampicin, streptomycin). Eight (3.5%) of the isolates were multidrug-resistant (MDR-TB), while no extensively drug

New Results from the Geoengineering Model Intercomparison Project (GeoMIP)

NASA Astrophysics Data System (ADS)

Robock, A.; Kravitz, B.

2013-12-01

The Geoengineering Model Intercomparison Project (GeoMIP) was designed to determine robust climate system model responses to Solar Radiation Management (SRM). While mitigation (reducing greenhouse gases emissions) is the most effective way of reducing future climate change, SRM (the deliberate modification of incoming solar radiation) has been proposed as a means of temporarily alleviating some of the effects of global warming. For society to make informed decisions as to whether SRM should ever be implemented, information is needed on the benefits, risks, and side effects, and GeoMIP seeks to aid in that endeavor. GeoMIP has organized four standardized climate model simulations involving reduction of insolation or increased amounts of stratospheric sulfate aerosols to counteract increasing greenhouse gases. Thirteen comprehensive atmosphere-ocean general circulation models have participated in the project so far. GeoMIP is a 'CMIP Coordinated Experiment' as part of the Climate Model Intercomparison Project 5 (CMIP5) and has been endorsed by SPARC (Stratosphere-troposphere Processes And their Role in Climate). GeoMIP has held three international workshops and has produced a number of recent journal articles. GeoMIP has found that if increasing greenhouse gases could be counteracted with insolation reduction, the global average temperature could be kept constant, but global average precipitation would reduce, particularly in summer monsoon regions around the world. Temperature changes would also not be uniform. The tropics would cool, but high latitudes would warm, with continuing, but reduced sea ice and ice sheet melting. Temperature extremes would still increase, but not as much as without SRM. If SRM were halted all at once, there would be rapid temperature and precipitation increases at 5-10 times the rates from gradual global warming. SRM combined with CO2 fertilization would have small impacts on rice production in China, but would increase maize production

Intercomparison of OH and OH reactivity measurements in a high isoprene and low NO environment during the Southern Oxidant and Aerosol Study (SOAS)

NASA Astrophysics Data System (ADS)

Sanchez, Dianne; Jeong, Daun; Seco, Roger; Wrangham, Ian; Park, Jeong-Hoo; Brune, William H.; Koss, Abigail; Gilman, Jessica; de Gouw, Joost; Misztal, Pawel; Goldstein, Allen; Baumann, Karsten; Wennberg, Paul O.; Keutsch, Frank N.; Guenther, Alex; Kim, Saewung

2018-02-01

We intercompare OH and OH reactivity datasets from two different techniques, chemical ionization mass spectrometry (CIMS) and laser-induced fluorescence (LIF) in a high isoprene and low NO environment in a southeastern US forest during the Southern Oxidant and Aerosol Study (SOAS). An LIF instrument measured OH and OH reactivity at the top of a tower, a CIMS instrument measured OH at the top of the tower, and a CIMS based comparative reactivity method (CRM-CIMS) instrument deployed at the base of the tower measured OH reactivity. Averaged diel variations of OH and OH reactivity from these datasets agree within analytical uncertainty and correlations of LIF versus CIMS for OH and OH reactivity have slopes of 0.65 and 0.97, respectively. However, there are systematic differences between the measurement datasets. The CRM-CIMS measurements of OH reactivity were ∼16% lower than those by the LIF technique in the late afternoon. We speculate that it is caused by losses in the sampling line down to the CRM-CIMS instrument. On the other hand, we could not come up with a reasonable explanation for the difference in the LIF and CIMS OH datasets for early morning and late afternoon when OH is below 1 × 106 molecules cm-3. Nonetheless, results of this intercomparison exercise strengthen previous publications from the field site on OH concentrations and atmospheric reactivity.

Intercomparison of mid latitude storm diagnostics (IMILAST)

NASA Astrophysics Data System (ADS)

Neu, U.

2009-04-01

Diagnostics of the observed and projection of the future changes of extratropical storms are a key issue e.g. for insurance companies, risk management and adaptation planning. Storm-associated damages are amongst the highest losses due to natural disasters in the mid-latitudes. Therefore the knowledge of the future variability and change in extratropical cyclone frequency, intensity and track locations is crucial for the strategic planning and minimization of the disaster impacts. Future changes in the total number of storms might be small but major signals could occur in the characteristics of cyclone life cycle such as intensity, life time, track locations. The quantification of such trends is not independent from the methodologies for storm track detection applied to observational data and models. Comparison of differences in cyclone characteristics obtained using different methods from a single data set may be as large as or even exceed the differences between the results derived from different data sets using a single methodology. Even more, the metrics used become particularly sensitive, resulting in the fact that scientific studies may find seemingly contradictory results based on the same datasets. For users of storm track analyses and projections the results are very difficult to interprete. Thus, it would be very helpful if the research community would provide information in a kind of "handbook" which contains definitions and a description of the available different identification and tracking schemes as well as of the parameters used for the quantification of cyclone activity. It cannot be expected that there is an optimum or standard scheme that fulfills all needs. Rather, a proper knowledge about advantages and restrictions of different schemes must be obtained to be able to provide a synthesis of results rather than puzzling the scientific and the general public with apparently contradicing statements. The project IMILAST aims at providing a

Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM). I: Model intercomparison with current land use

USGS Publications Warehouse

Breuer, L.; Huisman, J.A.; Willems, P.; Bormann, H.; Bronstert, A.; Croke, B.F.W.; Frede, H.-G.; Graff, T.; Hubrechts, L.; Jakeman, A.J.; Kite, G.; Lanini, J.; Leavesley, G.; Lettenmaier, D.P.; Lindstrom, G.; Seibert, J.; Sivapalan, M.; Viney, N.R.

2009-01-01

This paper introduces the project on 'Assessing the impact of land use change on hydrology by ensemble modeling (LUCHEM)' that aims at investigating the envelope of predictions on changes in hydrological fluxes due to land use change. As part of a series of four papers, this paper outlines the motivation and setup of LUCHEM, and presents a model intercomparison for the present-day simulation results. Such an intercomparison provides a valuable basis to investigate the effects of different model structures on model predictions and paves the ground for the analysis of the performance of multi-model ensembles and the reliability of the scenario predictions in companion papers. In this study, we applied a set of 10 lumped, semi-lumped and fully distributed hydrological models that have been previously used in land use change studies to the low mountainous Dill catchment, Germany. Substantial differences in model performance were observed with Nash-Sutcliffe efficiencies ranging from 0.53 to 0.92. Differences in model performance were attributed to (1) model input data, (2) model calibration and (3) the physical basis of the models. The models were applied with two sets of input data: an original and a homogenized data set. This homogenization of precipitation, temperature and leaf area index was performed to reduce the variation between the models. Homogenization improved the comparability of model simulations and resulted in a reduced average bias, although some variation in model data input remained. The effect of the physical differences between models on the long-term water balance was mainly attributed to differences in how models represent evapotranspiration. Semi-lumped and lumped conceptual models slightly outperformed the fully distributed and physically based models. This was attributed to the automatic model calibration typically used for this type of models. Overall, however, we conclude that there was no superior model if several measures of model

Stratospheric water vapor and ozone evaluation in reanalyses as part of the SPARC Reanalysis Intercomparison Project (S-RIP)

NASA Astrophysics Data System (ADS)

Davis, S. M.; Hegglin, M. I.; Fujiwara, M.; Manney, G. L.; Dragani, R.; Nash, E.; Tegtmeier, S.; Kobayashi, C.; Harada, Y.; Long, C. S.; Wargan, K.; Rosenlof, K. H.

2017-12-01

Reanalyses are widely used to understand atmospheric processes and past variability, and are often used to stand in as "observations" for comparisons with climate model output. Because of the central role of water vapor (WV) and ozone (O3) in climate change, it is important to understand how accurately and consistently these species are represented in existing global reanalyses. Here we present the results of WV and O3 intercomparisons that have been performed as part of the SPARC (Stratosphere-troposphere Processes and their Role in Climate) Reanalysis Intercomparison Project (S-RIP). The comparisons cover a range of timescales and evaluate both inter-reanalysis and observation-reanalysis differences. The assimilation of total column ozone (TCO) observations in newer reanalyses results in realistic representations of TCO in reanalyses except when data coverage is lacking, such as during polar night. The vertical distribution of ozone is also relatively well represented in the stratosphere in reanalyses, particularly given the relatively weak constraints on ozone vertical structure provided by most assimilated observations and the simplistic representations of ozone photochemical processes in most of the reanalysis forecast models. For times when vertically resolved observations are not assimilated, biases in the vertical distribution of ozone are found in the upper troposphere and lower stratosphere in all reanalyses. In contrast to O3, reanalysis stratospheric WV fields are not directly constrained by assimilated data. Observations of atmospheric humidity are typically used only in the troposphere, below a specified vertical level at or near the tropopause. The fidelity of reanalysis stratospheric WV products is therefore dependent on the reanalyses' representation of processes that influence stratospheric WV, such as tropical tropopause layer temperatures and methane oxidation. The lack of assimilated observations and known deficiencies in the representation of

Clinical laboratory studies of disinfection with Sporicidin.

PubMed Central

Isenberg, H D

1985-01-01

The clinical microbiology laboratory evaluation of disinfectants can serve as a guide for their application to reduce hospital-acquired infections. The use of Sporicidin, a glutaraldehyde-phenol formulation, was evaluated by the application of modified MIC and MBC determinations for standard organisms. In addition, the effect of this formulation on bacteria that may proliferate in water at ambient temperatures was studied. This investigation indicated that such studies can help the clinical microbiologist to guide the use of disinfectants and sterilants for the maintenance of a safe hospital environment. PMID:3932457

Three models intercomparison for Quantitative Precipitation Forecast over Calabria

NASA Astrophysics Data System (ADS)

Federico, S.; Avolio, E.; Bellecci, C.; Colacino, M.; Lavagnini, A.; Accadia, C.; Mariani, S.; Casaioli, M.

2004-11-01

In the framework of the National Project “Sviluppo di distretti industriali per le Osservazioni della Terra” (Development of Industrial Districts for Earth Observations) funded by MIUR (Ministero dell'Università e della Ricerca Scientifica --Italian Ministry of the University and Scientific Research) two operational mesoscale models were set-up for Calabria, the southernmost tip of the Italian peninsula. Models are RAMS (Regional Atmospheric Modeling System) and MM5 (Mesoscale Modeling 5) that are run every day at Crati scrl to produce weather forecast over Calabria (http://www.crati.it). This paper reports model intercomparison for Quantitative Precipitation Forecast evaluated for a 20 month period from 1th October 2000 to 31th May 2002. In addition to RAMS and MM5 outputs, QBOLAM rainfall fields are available for the period selected and included in the comparison. This model runs operationally at “Agenzia per la Protezione dell'Ambiente e per i Servizi Tecnici”. Forecasts are verified comparing models outputs with raingauge data recorded by the regional meteorological network, which has 75 raingauges. Large-scale forcing is the same for all models considered and differences are due to physical/numerical parameterizations and horizontal resolutions. QPFs show differences between models. Largest differences are for BIA compared to the other considered scores. Performances decrease with increasing forecast time for RAMS and MM5, whilst QBOLAM scores better for second day forecast.

Intercomparison of middle-atmospheric wind in observations and models

NASA Astrophysics Data System (ADS)

Rüfenacht, Rolf; Baumgarten, Gerd; Hildebrand, Jens; Schranz, Franziska; Matthias, Vivien; Stober, Gunter; Lübken, Franz-Josef; Kämpfer, Niklaus

2018-04-01

Wind profile information throughout the entire upper stratosphere and lower mesosphere (USLM) is important for the understanding of atmospheric dynamics but became available only recently, thanks to developments in remote sensing techniques and modelling approaches. However, as wind measurements from these altitudes are rare, such products have generally not yet been validated with (other) observations. This paper presents the first long-term intercomparison of wind observations in the USLM by co-located microwave radiometer and lidar instruments at Andenes, Norway (69.3° N, 16.0° E). Good correspondence has been found at all altitudes for both horizontal wind components for nighttime as well as daylight conditions. Biases are mostly within the random errors and do not exceed 5-10 m s-1, which is less than 10 % of the typically encountered wind speeds. Moreover, comparisons of the observations with the major reanalyses and models covering this altitude range are shown, in particular with the recently released ERA5, ECMWF's first reanalysis to cover the whole USLM region. The agreement between models and observations is very good in general, but temporally limited occurrences of pronounced discrepancies (up to 40 m s-1) exist. In the article's Appendix the possibility of obtaining nighttime wind information about the mesopause region by means of microwave radiometry is investigated.

An Experimental Study of a BSCS-Style Laboratory Approach for University General Biology.

ERIC Educational Resources Information Center

Leonard, William H.

1983-01-01

A Biological Sciences Curriculum Study (BSCS) inquiry approach for university general biology laboratory was tested against a well-established commercial program judged to be highly directive. The BSCS was found to be more effective in learning biology laboratory concepts than the commercial program as measured by a laboratory concepts test.…

Safety in the Chemical Laboratory. Epidemiology of Accidents in Academic Chemistry Laboratories, Part 2. Accident Intervention Study, Legal Aspects, and Observations.

ERIC Educational Resources Information Center

Hellmann, Margaret A.; And Others

1986-01-01

Reports on a chemistry laboratory accident intervention study conducted throughout the state of Colorado. Addresses the results of an initial survey of institutions of higher learning. Discusses some legal aspects concerning academic chemistry accidents. Provides some observations about academic chemistry laboratory accidents on the whole. (TW)

Tracer Studies In A Laboratory Beach Subjected To Waves

EPA Science Inventory

This work investigated the washout of dissolved nutrients from beaches due to waves by conducting tracer studies in a laboratory beach facility. The effects of waves were studied in the case where the beach was subjected to the tide, and that in which no tidal action was present...

Preliminary study: Formaldehyde exposure in laboratories of Sharjah university in UAE

PubMed Central

Ahmed, Hafiz Omer

2011-01-01

Objectives Laboratory technicians, students, and instructors are at high risk, because they deal with chemicals including formaldehyde. Thus, this preliminary study was conducted to measure the concentration of formaldehyde in the laboratories of the University of Sharjah in UAE. Materials and Methods: Thirty-two air samples were collected and analyzed for formaldehyde using National Institute for Occupational Safety and Health (NIOSH) method 3500. In this method, formaldehyde reacts with chromotropic acid in the presence of sulfuric acid to form a colored solution. The absorbance of the colored solution is read in spectrophotometer at wavelength 580 nm and is proportional to the quantity of the formaldehyde in the solution. Results: For the anatomy laboratory and in the presence of the covered cadaver, the mean concentration of formaldehyde was found to be 0.100 ppm with a range of 0.095–0.105 ppm. Whereas for the other laboratories, the highest mean concentration of formaldehyde was 0.024 ppm in the general microbiology laboratory and the lowest mean concentration of formaldehyde was 0.001 ppm in the environmental health laboratory. The 8-hour (time-weighted average) concentration of formaldehyde was found to be ranging between 0.0003 ppm in environmental health laboratory and 0.026 ppm in the anatomy laboratory. Conclusions: The highest level of concentration of formaldehyde in the presence of the covered cadaver in anatomy laboratory exceeded the recommended ceiling standard established by USA-NIOSH which is 0.1 ppm, but below the ceiling standard established by American Conference of Governmental Industrial Hygienists which is 0.3 ppm. Thus, it is recommended that formaldehyde levels should be measured periodically specially during the dissection in the anatomy laboratory, and local exhaust ventilation system should be installed and personal protective equipment such as safety glass and gloves should be available and be used to prevent direct skin or eye

[Implementation of quality standard UNE-EN ISO/IEC 17043 in the External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology].

PubMed

Poveda Gabaldón, Marta; Ovies, María Rosario; Orta Mira, Nieves; Serrano, M del Remedio Guna; Avila, Javier; Giménez, Alicia; Cardona, Concepción Gimeno

2011-12-01

The quality standard "UNE-EN-ISO 17043: 2010. Conformity assessment. General requirements for proficiency testing" applies to centers that organize intercomparisons in all areas. In the case of clinical microbiology laboratories, these intercomparisons must meet the management and technical standards required to achieve maximum quality in the performance of microbiological analysis and the preparation of test items (sample, product, data or other information used in the proficiency test) to enable them to be accredited. Once accredited, these laboratories can operate as a tool for quality control laboratories and competency assessment. In Spain, accreditation is granted by the Spanish Accreditation Body [Entidad Nacional de Acreditación (ENAC)]. The objective of this review is to explain how to apply the requirements of the standard to laboratories providing intercomparisons in the field of clinical microbiology (the organization responsible for all the tasks related to the development and operation of a proficiency testing program). This requires defining the scope and specifying the technical requirements (personnel management, control of equipment, facilities and environment, the design of the proficiency testing and data analysis for performance evaluation, communication with participants and confidentiality) and management requirements (document control, purchasing control, monitoring of complaints / claims, non-compliance, internal audits and management reviews). Copyright © 2011 Elsevier España S.L. All rights reserved.

Collaborative Study of Analysis of High Resolution Infrared Atmospheric Spectra Between NASA Langley Research Center and the University of Denver

NASA Technical Reports Server (NTRS)

Goldman, Aaron

1999-01-01

The Langley-D.U. collaboration on the analysis of high resolution infrared atmospheric spectra covered a number of important studies of trace gases identification and quantification from field spectra, and spectral line parameters analysis. The collaborative work included: Quantification and monitoring of trace gases from ground-based spectra available from various locations and seasons and from balloon flights. Studies toward identification and quantification of isotopic species, mostly oxygen and Sulfur isotopes. Search for new species on the available spectra. Update of spectroscopic line parameters, by combining laboratory and atmospheric spectra with theoretical spectroscopy methods. Study of trends of atmosphere trace constituents. Algorithms developments, retrievals intercomparisons and automatization of the analysis of NDSC spectra, for both column amounts and vertical profiles.

Results of the August 1977 Soviet and American meterological rocketsonde intercomparison held at Wallops Island, Virginia

NASA Technical Reports Server (NTRS)

Schmidlin, F. J.; Duke, J. R.; Ivanovsky, A. I.; Chernyshenko, Y. M.

1980-01-01

A coordinated program of rocketsonde investigations along about 60 deg E and 70 deg W between the United States and U.S.S.R. is discussed. The rocketsonde instruments used by the U.S. and U.S.S.R. were compared and the results are presented. The U.S. Super Loki Datasonde and the U.S.S.R. M100B rocketsonde are discussed. Results indicate that the U.S/U.S.S.R. rocketsonde measurement agreement improved since the 1973 intercomparisons. It was learned that the mean of the differences of the temperatures compare to within 6 C at about 60 km and to within 2 C near 50 km. Wind measurements were also found to agree.

[Quality assessment of microscopic examination in tuberculosis diagnostic laboratories: a preliminary study].

PubMed

Simşek, Hülya; Ceyhan, Ismail; Tarhan, Gülnur; Güner, Uğur

2010-10-01

Recently, the diagnosis of pulmonary tuberculosis (TB) has based on smear microscopy in the Direct Observed Treatment Strategy (DOTS) programme which provides the basis of treatment worldwide. Microscopic detection of AFB (Acid-Fast Bacilli) is one of the main components in the National TB Control Programmes (NTCP). Precision level in microscopy procedures and evaluations are the most important steps for accurate diagnosis of the disease and to initiate proper treatment. Therefore, the external quality assessment (EQA) is the most important implement to provide the reliability and validity of tests. In countries where NTCP are performed, this task is fulfilled by the National Reference Laboratories (NRL) according to the guidelines of the World Health Organization (WHO). For this purpose a pilot study was initiated by the central NRL of Turkey for EQA of AFB smear microscopy as part of the NTCP on January 1, 2005. A total of 5 laboratories of which 2 were district TB laboratories (A, B), 2 were tuberculosis control dispensaries (C, D), 1 was a national reference laboratory (E), participated in this study. Blind re-checking method (re-examination of randomly selected slides) was used for the evaluation, and the slides were sent to the central NRL with 3 months interval, four times a year, selected according to LQAS (Lot Quality Assurance Sampling) guides. In the re-evaluation of the slides, false positivity (FP), false negativity (FN) and quantification errors (QE) were noted. Laboratory A, sent totally 525 slides between January 1, 2005 and April 1, 2008. In the result of re-checking, 514 (97.9%) slides were found concordant, and 11 (2.1%) were discordant (10 FP, 1 FN). Laboratory B, participated in the study between October 1, 2005 and July 1, 2006 and of the 67 re-examined slides, 60 (89.5%) were concordant and 7 (10.5%) were discordant (2 FP, 0 FN, 5 QE). Laboratory C, sent 235 slides between January 1, 2005 and April 1, 2006; of them 218 (92.8%) were detected

The Latest SORCE Solar Spectral Irradiance Data Release: Inter-Comparison and a First Look at TSIS SIM Measurement.

NASA Astrophysics Data System (ADS)

Beland, S.; Sandoval, L.; Vanier, B.; Elliott, J.; Harder, J. W.; Snow, M. A.; Woods, T. N.; Richard, E. C.; Pilewskie, P.

2017-12-01

The Spectral Irradiance Monitor (SIM), the SOLar STellar Irradiance Comparison Experiment (SOLSTICE), and the XUV Photometer System (XPS) instruments on board the Solar Radiation and Climate Experiment (SORCE) mission have been taking daily Solar spectral irradiance (SSI) measurements since April 2003. We present the latest data releases from these instruments, describing the improvements in the new datasets and the trends measured during Solar cycles 23 and 24. An inter-comparison of the SSI over the overlapping wavelengths for SIM and SOLSTICE is presented as well as, if the data is available, a comparison with the first light measurements from TSIS-SIM.

The Model Intercomparison Project on the Climatic Response to Volcanic Forcing (VolMIP): Experimental Design and Forcing Input Data for CMIP6

NASA Technical Reports Server (NTRS)

Zanchettin, Davide; Khodri, Myriam; Timmreck, Claudia; Toohey, Matthew; Schmidt, Anja; Gerber, Edwin P.; Hegerl, Gabriele; Robock, Alan; Pausata, Francesco; Ball, William T.;

The Dresden Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics - Status and first physics program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ilgner, Ch.

Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, protected from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, inmore » the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise using the same High-Purity Ge detector at several sites has shown that, with a combination of 45 m rock overburden, as can be found in the Felsenkeller underground site in Dresden, and an active veto against the remaining muon flux, in a typical nuclear astrophysics setup a background level can be achieved that is similar to the deep underground scenario as in the Gran- Sasso underground laboratory, for instance. Recently, a muon background study and geodetic measurements were carried out by the REGARD group. It was estimated that the rock overburden at the place of the future ion accelerator is equivalent to 130 m of water. The maximum muon flux measured was 2.5 m{sup -2} sr{sup -1} s{sup -1}, in the direction of the tunnel entrance. Based on this finding, a used 5 MV pelletron tandem accelerator with 250 μA up-charge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is in progress and far advanced. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and

How toxic is coal ash? A laboratory toxicity case study

DOE PAGES

Sherrard, Rick M.; Carriker, Neil; Greeley, Jr., Mark Stephen

2014-12-08

Under a consent agreement among the Environmental Protection Agency (EPA) and proponents both for and against stricter regulation, EPA is to issue a new coal ash disposal rule by the end of 2014. Laboratory toxicity investigations often yield conservative estimates of toxicity because many standard test species are more sensitive than resident species, thus could provide information useful to the rule-making. However, few laboratory studies of coal ash toxicity are available; most studies reported in the literature are based solely on field investigations. In this paper, we describe a broad range of toxicity studies conducted for the Tennessee Valley Authoritymore » (TVA) Kingston ash spill, results of which help provide additional perspective on the toxicity of coal ash.« less

Comparing apples and oranges: the Community Intercomparison Suite

NASA Astrophysics Data System (ADS)

Schutgens, Nick; Stier, Philip; Pascoe, Stephen

2014-05-01

Visual representation and comparison of geoscientific datasets presents a huge challenge due to the large variety of file formats and spatio-temporal sampling of data (be they observations or simulations). The Community Intercomparison Suite attempts to greatly simplify these tasks for users by offering an intelligent but simple command line tool for visualisation and colocation of diverse datasets. In addition, CIS can subset and aggregate large datasets into smaller more manageable datasets. Our philosophy is to remove as much as possible the need for specialist knowledge by the user of the structure of a dataset. The colocation of observations with model data is as simple as: "cis col ::" which will resample the simulation data to the spatio-temporal sampling of the observations, contingent on a few user-defined options that specify a resampling kernel. CIS can deal with both gridded and ungridded datasets of 2, 3 or 4 spatio-temporal dimensions. It can handle different spatial coordinates (e.g. longitude or distance, altitude or pressure level). CIS supports both HDF, netCDF and ASCII file formats. The suite is written in Python with entirely publicly available open source dependencies. Plug-ins allow a high degree of user-moddability. A web-based developer hub includes a manual and simple examples. CIS is developed as open source code by a specialist IT company under supervision of scientists from the University of Oxford as part of investment in the JASMIN superdatacluster facility at the Centre of Environmental Data Archival.

Consistency of climate change projections from multiple global and regional model intercomparison projects

NASA Astrophysics Data System (ADS)

Fernández, J.; Frías, M. D.; Cabos, W. D.; Cofiño, A. S.; Domínguez, M.; Fita, L.; Gaertner, M. A.; García-Díez, M.; Gutiérrez, J. M.; Jiménez-Guerrero, P.; Liguori, G.; Montávez, J. P.; Romera, R.; Sánchez, E.

2018-03-01

We present an unprecedented ensemble of 196 future climate projections arising from different global and regional model intercomparison projects (MIPs): CMIP3, CMIP5, ENSEMBLES, ESCENA, EURO- and Med-CORDEX. This multi-MIP ensemble includes all regional climate model (RCM) projections publicly available to date, along with their driving global climate models (GCMs). We illustrate consistent and conflicting messages using continental Spain and the Balearic Islands as target region. The study considers near future (2021-2050) changes and their dependence on several uncertainty sources sampled in the multi-MIP ensemble: GCM, future scenario, internal variability, RCM, and spatial resolution. This initial work focuses on mean seasonal precipitation and temperature changes. The results show that the potential GCM-RCM combinations have been explored very unevenly, with favoured GCMs and large ensembles of a few RCMs that do not respond to any ensemble design. Therefore, the grand-ensemble is weighted towards a few models. The selection of a balanced, credible sub-ensemble is challenged in this study by illustrating several conflicting responses between the RCM and its driving GCM and among different RCMs. Sub-ensembles from different initiatives are dominated by different uncertainty sources, being the driving GCM the main contributor to uncertainty in the grand-ensemble. For this analysis of the near future changes, the emission scenario does not lead to a strong uncertainty. Despite the extra computational effort, for mean seasonal changes, the increase in resolution does not lead to important changes.

Intercomparison NaI(Tl) and HPGe spectrometry to studies of natural radioactivity on geological samples.

PubMed

Hung, Nguyen Quoc; Chuong, Huynh Dinh; Vuong, Le Quang; Thanh, Tran Thien; Tao, Chau Van

2016-11-01

In this study, in situ gamma spectra using NaI(Tl) detector have been compared with the laboratory measurements by using HPGe detector on geological samples. The results for measuring naturally occurring terrestrial gamma radiation of 4 0 K and the decay series of 232 Th and, 238 U respectively of both detectors show a maximum deviation about 5%. The mass activities series from both detectors were checked for coherence using proficiency test procedure from the International Atomic Energy Agency. The reliability and precision pass for final scores for all the analytical determinations of are received "acceptable" for all radionuclides. Copyright © 2016 Elsevier Ltd. All rights reserved.

An international study of how laboratories handle and evaluate patient samples after detecting an unexpected APTT prolongation.

PubMed

Ajzner, Éva; Rogic, Dunja; Meijer, Piet; Kristoffersen, Ann Helen; Carraro, Paolo; Sozmen, Eser; Faria, Ana Paula; Sandberg, Sverre

2015-09-01

An unexpectedly detected prolonged activated partial thromboplastin time (APTT) can be a harmless laboratory finding, but can also reflect a thrombotic tendency or a bleeding disorder. The assistance of laboratory professionals in the interpretation of an unexpectedly detected prolonged APTT (uAPTT) is often required. The way in which uAPTTs are evaluated in laboratories was assessed in this international study with the aim of determining whether laboratory professionals are able to fulfill this need. Postanalytical practices after uAPTT were investigated and the mixing study methodology (if used) was studied by circulating a case report with a questionnaire to staff in the invited laboratories. In addition, the interpretations of those staff regarding the presence or absence of inhibitors in three APTT mixing study scenarios were examined. Large within- and between-country variations were detected in both postanalytical practices and mixing study methodologies among the 990 responding laboratories, 90% of which were in 13 countries. Shortcomings regarding the investigation of uAPTTs leading to potentially incorrect or delayed clinical diagnoses were found in 88% of the laboratories. Of the laboratories to which the interpretative questions were sent, 49% interpreted all mixing study scenarios correctly. uAPTTs were investigated appropriately and all mixing study scenarios interpreted correctly in parallel in only 9.6% of the participating laboratories. The clinical requirement for the assistance of laboratory professionals in the interpretation of uAPTTs cannot be met at most of the participating laboratories. Laboratory professionals should be trained in the evaluation of ordinary laboratory tests, such as that for uAPTTs.

Global inter-comparison of microwave and infrared LST from multiple sensors (AMSR-E, MODIS, SEVIRI, GOES, and MTSAT-2)

NASA Astrophysics Data System (ADS)

Ermida, Sofia L.; Jiménez, Carlos; Prigent, Catherine; Trigo, Isabel F.; DaCamara, Carlos C.

2017-04-01

Land Surface Temperature (LST) is an important diagnostic parameter of land surface conditions. Satellite LST products generally rely on measurements in the thermal infrared (IR) atmospheric window, which only allows clear sky estimates. Microwave (MW) observations can alternatively be used to derive an all-weather LST. Here we present an inter-comparison between LST derived from the Advanced Microwave Scanning Radiometer - Earth observation system (AMSR-E), the MODerate resolution Imaging Spectroradiometer (MODIS) on-board Aqua, the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on-board Meteosat Second Generation (MSG) satellites, the Geostationary Operational Environmental Satellite (GOES) and the Japanese Meteorological Imager (JAMI) on-board the Multifunction Transport SATellite (MTSAT-2). The higher discrepancies between MW and IR products are observed over snow covered areas. MW emissivity is highly variable for snow-covered ground and not always properly accounted for by the climatological emissivity used in the retrieval. There is a conspicuous bias between MODIS and AMSR-E over desert areas, which is most likely related to the underestimation of LST by MODIS as previously reported in other studies. Inter-comparison between all IR and MW retrievals shows that the STD of the differences between MW and IR LST is generally higher than between IR retrievals. However, the biases between MW and IR LST are, in some cases, of the same order as the ones observed among infrared products. In particular, GOES presents a daytime bias with respect to AMSR-E of 0.45 K whereas the bias with respect to MODIS is 0.60 K. Given that AMSR-E can provide LST under cloudy conditions, the use of microwaves, considering simultaneous overpasses with IR, represents an increase of more than 250% of the number of available LST estimates over equatorial regions. With the MW products of a comparable quality to the IR ones, the MW LST is a very powerful complement of the IR

Report of the Field and Laboratory Utilization Study Group. Appendix

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1975-12-01

These appendices (ERDA organization and management, summary of other resources, and FLU study considerations/inputs) provide detailed and quantitative information in support of the findings and recommendations presented in the report of the field and laboratory utilization study group. (RWR)

Experimental design for three interrelated marine ice sheet and ocean model intercomparison projects: MISMIP v. 3 (MISMIP +), ISOMIP v. 2 (ISOMIP +) and MISOMIP v. 1 (MISOMIP1)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asay-Davis, Xylar S.; Cornford, Stephen L.; Durand, Gaël

Coupled ice sheet-ocean models capable of simulating moving grounding lines are just becoming available. Such models have a broad range of potential applications in studying the dynamics of marine ice sheets and tidewater glaciers, from process studies to future projections of ice mass loss and sea level rise. The Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP) is a community effort aimed at designing and coordinating a series of model intercomparison projects (MIPs) for model evaluation in idealized setups, model verification based on observations, and future projections for key regions of the West Antarctic Ice Sheet (WAIS). Here we describe computationalmore » experiments constituting three interrelated MIPs for marine ice sheet models and regional ocean circulation models incorporating ice shelf cavities. These consist of ice sheet experiments under the Marine Ice Sheet MIP third phase (MISMIP+), ocean experiments under the Ice Shelf-Ocean MIP second phase (ISOMIP+) and coupled ice sheet-ocean experiments under the MISOMIP first phase (MISOMIP1). All three MIPs use a shared domain with idealized bedrock topography and forcing, allowing the coupled simulations (MISOMIP1) to be compared directly to the individual component simulations (MISMIP+ and ISOMIP+). The experiments, which have qualitative similarities to Pine Island Glacier Ice Shelf and the adjacent region of the Amundsen Sea, are designed to explore the effects of changes in ocean conditions, specifically the temperature at depth, on basal melting and ice dynamics. In future work, differences between model results will form the basis for the evaluation of the participating models.« less

A Methodological Intercomparison of Topographic and Aerial Photographic Habitat Survey Techniques

NASA Astrophysics Data System (ADS)

Bangen, S. G.; Wheaton, J. M.; Bouwes, N.

2011-12-01

A severe decline in Columbia River salmonid populations and subsequent Federal listing of subpopulations has mandated both the monitoring of populations and evaluation of the status of available habitat. Numerous field and analytical methods exist to assist in the quantification of the abundance and quality of in-stream habitat for salmonids. These methods range from field 'stick and tape' surveys to spatially explicit topographic and aerial photographic surveys from a mix of ground-based and remotely sensed airborne platforms. Although several previous studies have assessed the quality of specific individual survey methods, the intercomparison of competing techniques across a diverse range of habitat conditions (wadeable headwater channels to non-wadeable mainstem channels) has not yet been elucidated. In this study, we seek to enumerate relative quality (i.e. accuracy, precision, extent) of habitat metrics and inventories derived from an array of ground-based and remotely sensed surveys of varying degrees of sophistication, as well as quantify the effort and cost in conducting the surveys. Over the summer of 2010, seven sample reaches of varying habitat complexity were surveyed in the Lemhi River Basin, Idaho, USA. Complete topographic surveys were attempted at each site using rtkGPS, total station, ground-based LiDaR and traditional airborne LiDaR. Separate high spatial resolution aerial imagery surveys were acquired using a tethered blimp, a drone UAV, and a traditional fixed-wing aircraft. Here we also developed a relatively simplistic methodology for deriving bathymetry from aerial imagery that could be readily employed by instream habitat monitoring programs. The quality of bathymetric maps derived from aerial imagery was compared with rtkGPS topographic data. The results are helpful for understanding the strengths and weaknesses of different approaches in specific conditions, and how a hybrid of data acquisition methods can be used to build a more complete

Laboratory and Space Plasma Studies

NASA Astrophysics Data System (ADS)

Hyman, Ellis

1996-08-01

The work performed by Science Applications International Corporation (SAIC), encompasses a wide range of topics in experimental, computational, and analytical laboratory and space plasma physics. The accomplishments described in this report have been in support of the programs of the Laser Plasma Branch (Code 6730) and other segments of the Plasma Physics Division at the Naval Research Laboratory (NRL) and cover the period 27 September 1993 to August 1, 1996. SAIC's efforts have been supported by sub-contracts or consulting agreements with Pulse Sciences, Inc., Clark Richardson, and Biskup Consulting Engineers, Pharos Technical Enterprises, Plex Corporation, Cornell University, Stevens Institute of Technology, the University of Connecticut, Plasma Materials and Technologies, Inc., and GaSonics International, Inc. In the following discussions section we will describe each of the topics investigated and the results obtained. Much of the research work has resulted in journal publications and NRL Memorandum Reports in which the investigation is described in detail. These reports are included as Appendices to this Final Report.

NETL Extreme Drilling Laboratory Studies High Pressure High Temperature Drilling Phenomena

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyons, K.D.; Honeygan, S.; Moroz, T.H.

2008-12-01

The U.S. Department of Energy's National Energy Technology Laboratory (NETL) established the Extreme Drilling Laboratory to engineer effective and efficient drilling technologies viable at depths greater than 20,000 ft. This paper details the challenges of ultradeep drilling, documents reports of decreased drilling rates as a result of increasing fluid pressure and temperature, and describes NETL's research and development activities. NETL is invested in laboratory-scale physical simulation. Its physical simulator will have capability of circulating drilling fluids at 30,000 psi and 480°F around a single drill cutter. This simulator is not yet operational; therefore, the results will be limited to themore » identification of leading hypotheses of drilling phenomena and NETL's test plans to validate or refute such theories. Of particular interest to the Extreme Drilling Laboratory's studies are the combinatorial effects of drilling fluid pressure, drilling fluid properties, rock properties, pore pressure, and drilling parameters, such as cutter rotational speed, weight on bit, and hydraulics associated with drilling fluid introduction to the rock-cutter interface. A detailed discussion of how each variable is controlled in a laboratory setting will be part of the conference paper and presentation.« less

The Global Precipitation Climatology Project: First Algorithm Intercomparison Project

NASA Technical Reports Server (NTRS)

Arkin, Phillip A.; Xie, Pingping

1994-01-01

The Global Precipitation Climatology Project (GPCP) was established by the World Climate Research Program to produce global analyses of the area- and time-averaged precipitation for use in climate research. To achieve the required spatial coverage, the GPCP uses simple rainfall estimates derived from IR and microwave satellite observations. In this paper, we describe the GPCP and its first Algorithm Intercomparison Project (AIP/1), which compared a variety of rainfall estimates derived from Geostationary Meteorological Satellite visible and IR observations and Special Sensor Microwave/Imager (SSM/I) microwave observations with rainfall derived from a combination of radar and raingage data over the Japanese islands and the adjacent ocean regions during the June and mid-July through mid-August periods of 1989. To investigate potential improvements in the use of satellite IR data for the estimation of large-scale rainfall for the GPCP, the relationship between rainfall and the fractional coverage of cold clouds in the AIP/1 dataset is examined. Linear regressions between fractional coverage and rainfall are analyzed for a number of latitude-longitude areas and for a range of averaging times. The results show distinct differences in the character of the relationship for different portions of the area. These results suggest that the simple IR-based estimation technique currently used in the GPCP can be used to estimate rainfall for global tropical and subtropical areas, provided that a method for adjusting the proportional coefficient for varying areas and seasons can be determined.

ESCOMPTE experiment: intercomparison of four aircraft dynamical, thermodynamical, radiation and chemical measurements

NASA Astrophysics Data System (ADS)

Saïd, F.; Corsmeier, U.; Kalthoff, N.; Kottmeier, C.; Lothon, M.; Wieser, A.; Hofherr, T.; Perros, P.

2005-03-01

Among seven airplanes involved in the Experience sur Site pour COntraindre les Modèles de Pollution atmosphérique et de Transport d'Emission (ESCOMPTE) experiment in 2001, four measured classical meteorological parameters, radiation fluxes, trace gases and turbulence (for three among four): the Dornier 128 from the Institut für Meteorologie und Klimaforschung, the Fokker 27 ARAT from the Institut National des Sciences de l'Univers, the Merlin 4 and Piper Aztec 23 from Météo France. This paper presents the results of intercomparison flights between three pairs of aircraft. The results are very similar for mean parameters except for the horizontal wind measurements provided by the Merlin that showed a problem that is probably linked to the measurement of the aircraft velocity. Further investigation is required to know whether corrections are possible or not for these wind measurements. Turbulence is studied along two legs over a flat and homogeneous area: in spite of the heterogeneity of the measured functions (one leg is close to the top of the boundary layer), the comparison is rather good. The relative accuracy of the data provided to the data base is given. It easily allows to use the huge amount of aircraft data collected during the experiment with very few restrictions. We underline some points where efforts should be borne for future experiments: wind coupling between Inertial Navigation System data and Global Positioning System (GPS) data, CO and NO x measurements.

Laboratory Based Case Studies: Closer to the Real World

ERIC Educational Resources Information Center

Dinan, Frank J.

2005-01-01

Case-based laboratories offer students the chance to approximate real science. Based on interesting stories that pose problems requiring experimental solutions, they avoid the cookbook approach characteristic of traditional undergraduate laboratory instruction. Instead, case-based laboratories challenge students to develop, as much as possible,…

Laboratory studies of in vivo fluorescence of phytoplankton

NASA Technical Reports Server (NTRS)

Brown, C. A., Jr.; Farmer, F. H.; Jarrett, O., Jr.; Staton, W. L.

1978-01-01

A lidar system is developed that uses four selected excitation wavelengths to induce chlorophyll 'a' fluorescence which is indicative of both the concentration and diversity of phytoplankton. The operating principles of the system and the results of measurements of phytoplankton fluorescence in a controlled laboratory environment are presented. A comparative study of results from lidar fluorosensor laboratory tank tests using representative species of phytoplankton in single and multispecies cultures from each of four color groups reveals that (1) there is good correlation between the fluorescence of chlorophyll 'a' remotely simulated and detected by the lidar system and in-situ measurements using four similar excitation wavelengths in a flow-through fluorometer; (2) good correlation exists between the total chlorophyll 'a' calculated from lidar-fluorosensor data and measurements obtained by the Strickland-Parsons method; and (3) the lidar fluorosensor can provide an index of population diversity.

AN INTERLABORATORY COMPARISON ON THE DETERMINATION OF 241Am, 244Cm AND 252Cf IN URINE.

PubMed

Gerstmann, Udo C; Taubner, Kerstin; Hartmann, Martina

2016-09-01

An intercomparison exercise on the determination of (241)Am, (244)Cm and (252)Cf in urine was performed. Since it was designed with regard to emergency preparedness, the detection limit for each nuclide was set to 0.1 Bq per 24-h urine sample. Most of the participating laboratories were established bioassay laboratories. However, some laboratories that routinely determine (241)Am only in environmental samples were also invited in order to explore their potential for emergency bioassay analysis. Another aspect of the intercomparison was to investigate the performance of all laboratories concerning the chemical yields of the (243)Am tracer in comparison with (244)Cm and (252)Cf. In summary, both types of laboratories showed good results. There was a negative bias for the results of (244)Cm and (252)Cf, which can be explained by slightly different radiochemical behaviours of americium, curium and californium and which is in agreement with results reported in the literature. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Studying Sexual Aggression: A Review of the Evolution and Validity of Laboratory Paradigms

PubMed Central

Davis, Kelly Cue; George, William H.; Nagayama Hall, Gordon C.; Parrott, Dominic J.; Tharp, Andra Teten; Stappenbeck, Cynthia A.

2018-01-01

Objective Researchers have endeavored for decades to develop and implement experimental assessments of sexual aggression and its precursors to capitalize on the many scientific advantages offered by laboratory experiments, such as rigorous control of key variables and identification of causal relationships. The purpose of this review is to provide an overview of and commentary on the evolution of these laboratory-based methods. Conclusions To date, two primary types of sexual aggression laboratory studies have been developed: those that involve behavioral analogues of sexual aggression and those that assess postulated precursors to sexually aggressive behavior. Although the study of sexual aggression in the laboratory is fraught with methodological challenges, validity concerns, and ethical considerations, advances in the field have resulted in greater methodological rigor, more precise dependent measures, and improved experimental validity, reliability, and realism. Because highly effective sexual aggression prevention strategies remain elusive, continued laboratory-based investigation of sexual aggression coupled with translation of critical findings to the development and modification of sexual aggression prevention programs remains an important task for the field. PMID:29675289

Evaluation of Non-Laboratory and Laboratory Prediction Models for Current and Future Diabetes Mellitus: A Cross-Sectional and Retrospective Cohort Study

PubMed Central

Hahn, Seokyung; Moon, Min Kyong; Park, Kyong Soo; Cho, Young Min

2016-01-01

Background Various diabetes risk scores composed of non-laboratory parameters have been developed, but only a few studies performed cross-validation of these scores and a comparison with laboratory parameters. We evaluated the performance of diabetes risk scores composed of non-laboratory parameters, including a recently published Korean risk score (KRS), and compared them with laboratory parameters. Methods The data of 26,675 individuals who visited the Seoul National University Hospital Healthcare System Gangnam Center for a health screening program were reviewed for cross-sectional validation. The data of 3,029 individuals with a mean of 6.2 years of follow-up were reviewed for longitudinal validation. The KRS and 16 other risk scores were evaluated and compared with a laboratory prediction model developed by logistic regression analysis. Results For the screening of undiagnosed diabetes, the KRS exhibited a sensitivity of 81%, a specificity of 58%, and an area under the receiver operating characteristic curve (AROC) of 0.754. Other scores showed AROCs that ranged from 0.697 to 0.782. For the prediction of future diabetes, the KRS exhibited a sensitivity of 74%, a specificity of 54%, and an AROC of 0.696. Other scores had AROCs ranging from 0.630 to 0.721. The laboratory prediction model composed of fasting plasma glucose and hemoglobin A1c levels showed a significantly higher AROC (0.838, P < 0.001) than the KRS. The addition of the KRS to the laboratory prediction model increased the AROC (0.849, P = 0.016) without a significant improvement in the risk classification (net reclassification index: 4.6%, P = 0.264). Conclusions The non-laboratory risk scores, including KRS, are useful to estimate the risk of undiagnosed diabetes but are inferior to the laboratory parameters for predicting future diabetes. PMID:27214034

Bilateral Comparison of Mercury and Gallium Fixed-Point Cells Using Standard Platinum Resistance Thermometer

NASA Astrophysics Data System (ADS)

Bojkovski, J.; Veliki, T.; Zvizdić, D.; Drnovšek, J.

2011-08-01

The objective of project EURAMET 1127 (Bilateral comparison of triple point of mercury and melting point of gallium) in the field of thermometry is to compare realization of a triple point of mercury (-38.8344 °C) and melting point of gallium (29.7646 °C) between the Slovenian national laboratory MIRS/UL-FE/LMK and the Croatian national laboratory HMI/FSB-LPM using a long-stem 25 Ω standard platinum resistance thermometer (SPRT). MIRS/UL/FE-LMK participated in a number of intercomparisons on the level of EURAMET. On the other hand, the HMI/LPM-FSB laboratory recently acquired new fixed-point cells which had to be evaluated in the process of intercomparisons. A quartz-sheathed SPRT has been selected and calibrated at HMI/LPM-FSB at the triple point of mercury, the melting point of gallium, and the water triple point. A second set of measurements was made at MIRS/UL/FE-LMK. After its return, the SPRT was again recalibrated at HMI/LPM-FSB. In the comparison, the W value of the SPRT has been used. Results of the bilateral intercomparison confirmed that the new gallium cell of the HMI/LPM-FSB has a value that is within uncertainty limits of both laboratories that participated in the exercise, while the mercury cell experienced problems. After further research, a small leakage in the mercury fixed-point cell has been found.

A preliminary intercomparison between numerical upper wind forecasts and research aircraft measurements of jet streams

NASA Technical Reports Server (NTRS)

Shapiro, M. A.

1982-01-01

During the past several years, research on the structure of extra-tropical jet streams has been carried out with direct measurements with instrumented research aircraft from the National Center for Atmospheric Research (NCAR). These measurements have been used to describe the wind, temperature, turbulence and chemical characteristics of jet streams. A fundamental question is one of assessing the potential value of existing operational numerical forecast models for forecasting the meteorological conditions along commercial aviation flight routes so as to execute Minimum Flight Time tracks and thus obtain the maximum efficiency in aviation fuel consumption. As an initial attempt at resolving this question, the 12 hour forecast output from two models was expressed in terms of a common output format to ease their intercomparison. The chosen models were: (1) the Fine-Mesh Spectral hemispheric and (2) the Limited Area Fine Mesh (LFM) model.

A study of 6S workplace improvement in Ergonomic Laboratory

NASA Astrophysics Data System (ADS)

Sari, AD; Suryoputro, MR; Rahmillah, FI

2017-12-01

This article discusses 6S implementation in Ergonomic Laboratory, Department of Industrial Engineering, Islamic University of Indonesia. This research is improvement project of 5S implementation in Ergonomic laboratory. Referring to the 5S implementation of the previous year, there have been improvements from environmental conditions or a more organized workplace however there is still a lack of safety aspects. There are several safeties problems such as equipment arrangement, potential hazards of room dividers that cause injury several times, placement of fire extinguisher, no evacuation path and assembly point in case of fire, as well as expired hydrant condition and lack of awareness of stakeholders related to safety. Therefore, this study aims to apply the 6S kaizen method to the Ergonomic laboratory to facilitate the work process, reduce waste, improve work safety and improve staff performance. Based on the score 6S assessment increased audit results by 32 points, before implementation is 75 point while after implementation is 107 point. This has implications for better use for mitigate people in laboratory area, save time when looking for tools and materials, safe workplace, as well as improving the culture and spirit of ‘6S’ on staff due to better and safetier working environment.

Stability of the Atlantic meridional overturning circulation: A model intercomparison

NASA Astrophysics Data System (ADS)

Weaver, Andrew J.; Sedláček, Jan; Eby, Michael; Alexander, Kaitlin; Crespin, Elisabeth; Fichefet, Thierry; Philippon-Berthier, Gwenaëlle; Joos, Fortunat; Kawamiya, Michio; Matsumoto, Katsumi; Steinacher, Marco; Tachiiri, Kaoru; Tokos, Kathy; Yoshimori, Masakazu; Zickfeld, Kirsten

2012-10-01

The evolution of the Atlantic Meridional Overturning Circulation (MOC) in 30 models of varying complexity is examined under four distinct Representative Concentration Pathways. The models include 25 Atmosphere-Ocean General Circulation Models (AOGCMs) or Earth System Models (ESMs) that submitted simulations in support of the 5th phase of the Coupled Model Intercomparison Project (CMIP5) and 5 Earth System Models of Intermediate Complexity (EMICs). While none of the models incorporated the additional effects of ice sheet melting, they all projected very similar behaviour during the 21st century. Over this period the strength of MOC reduced by a best estimate of 22% (18%-25% 5%-95% confidence limits) for RCP2.6, 26% (23%-30%) for RCP4.5, 29% (23%-35%) for RCP6.0 and 40% (36%-44%) for RCP8.5. Two of the models eventually realized a slow shutdown of the MOC under RCP8.5, although no model exhibited an abrupt change of the MOC. Through analysis of the freshwater flux across 30°-32°S into the Atlantic, it was found that 40% of the CMIP5 models were in a bistable regime of the MOC for the duration of their RCP integrations. The results support previous assessments that it is very unlikely that the MOC will undergo an abrupt change to an off state as a consequence of global warming.

Urine culture contamination: a College of American Pathologists Q-Probes study of 127 laboratories.

PubMed

Bekeris, Leonas G; Jones, Bruce Allen; Walsh, Molly K; Wagar, Elizabeth A

2008-06-01

While urine culture contamination may not be completely avoidable, some laboratories have lower contamination rates than others. A College of American Pathologists (CAP) 1998 Q-Probes study showed that many interventions commonly assumed to reduce contamination were not demonstrably effective. This article revisits the issue. To examine the frequency of urine culture contamination, review current laboratory practices in the collection of urine culture specimens, and determine practice characteristics that may be associated with the contamination rate. Laboratories participating in a CAP Q-Probes study were required to prospectively collect data on 120 consecutive urine culture specimens and provide information on the patient's demographics (age and sex), the location where the specimen was collected, how the specimen was handled, the number of isolates in quantities greater than or equal to 10,000 colony-forming units (CFU)/mL, and whether the laboratory considered the specimen to be contaminated. Specific inclusion and exclusion criteria were provided to the participants. Each laboratory completed a supplemental questionnaire that probed for specific laboratory urine culture collection practices. One hundred twenty-seven laboratories participated in the study. Results from a total of 14,739 urine specimens were received. For the purpose of this study, a urine specimen was determined to be contaminated if the culture yielded more than 2 isolates in quantities greater than or equal to 10,000 CFU/mL. Using these criteria the median institution had a contamination rate of 15.0%. Laboratories in the 10th percentile (low performance) had an average contamination rate of 41.7%, while laboratories in the 90th percentile had an average rate of 0.8%. The collection site had no influence on the contamination rate, but postcollection processing, especially refrigeration of the specimen, had a substantial effect. Providing instruction to patients produced a statistically

GeoBrain Computational Cyber-laboratory for Earth Science Studies

NASA Astrophysics Data System (ADS)

Deng, M.; di, L.

2009-12-01

Computational approaches (e.g., computer-based data visualization, analysis and modeling) are critical for conducting increasingly data-intensive Earth science (ES) studies to understand functions and changes of the Earth system. However, currently Earth scientists, educators, and students have met two major barriers that prevent them from being effectively using computational approaches in their learning, research and application activities. The two barriers are: 1) difficulties in finding, obtaining, and using multi-source ES data; and 2) lack of analytic functions and computing resources (e.g., analysis software, computing models, and high performance computing systems) to analyze the data. Taking advantages of recent advances in cyberinfrastructure, Web service, and geospatial interoperability technologies, GeoBrain, a project funded by NASA, has developed a prototype computational cyber-laboratory to effectively remove the two barriers. The cyber-laboratory makes ES data and computational resources at large organizations in distributed locations available to and easily usable by the Earth science community through 1) enabling seamless discovery, access and retrieval of distributed data, 2) federating and enhancing data discovery with a catalogue federation service and a semantically-augmented catalogue service, 3) customizing data access and retrieval at user request with interoperable, personalized, and on-demand data access and services, 4) automating or semi-automating multi-source geospatial data integration, 5) developing a large number of analytic functions as value-added, interoperable, and dynamically chainable geospatial Web services and deploying them in high-performance computing facilities, 6) enabling the online geospatial process modeling and execution, and 7) building a user-friendly extensible web portal for users to access the cyber-laboratory resources. Users can interactively discover the needed data and perform on-demand data analysis and

Atmospheric cloud physics laboratory project study

NASA Technical Reports Server (NTRS)

Schultz, W. E.; Stephen, L. A.; Usher, L. H.

1976-01-01

Engineering studies were performed for the Zero-G Cloud Physics Experiment liquid cooling and air pressure control systems. A total of four concepts for the liquid cooling system was evaluated, two of which were found to closely approach the systems requirements. Thermal insulation requirements, system hardware, and control sensor locations were established. The reservoir sizes and initial temperatures were defined as well as system power requirements. In the study of the pressure control system, fluid analyses by the Atmospheric Cloud Physics Laboratory were performed to determine flow characteristics of various orifice sizes, vacuum pump adequacy, and control systems performance. System parameters predicted in these analyses as a function of time include the following for various orifice sizes: (1) chamber and vacuum pump mass flow rates, (2) the number of valve openings or closures, (3) the maximum cloud chamber pressure deviation from the allowable, and (4) cloud chamber and accumulator pressure.

Laboratory studies of the interaction of ions with condensed gases: Planetary applications

NASA Technical Reports Server (NTRS)

Boring, J. W.; Johnson, R. E.

1990-01-01

The work described is concerned with laboratory studies of the processes that produce the ejection of molecules from the surfaces of condensed gas solids, the change in the chemistry of the surface materials, and the relationship of these results to processes occurring in the solar system. Included is a discussion of the experimental techniques employed in making these laboratory measurements.

Groundwater flow and heat transport for systems undergoing freeze-thaw: Intercomparison of numerical simulators for 2D test cases

DOE PAGES

Grenier, Christophe; Anbergen, Hauke; Bense, Victor; ...

2018-02-26

In high-elevation, boreal and arctic regions, hydrological processes and associated water bodies can be strongly influenced by the distribution of permafrost. Recent field and modeling studies indicate that a fully-coupled multidimensional thermo-hydraulic approach is required to accurately model the evolution of these permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require verification. Here in this paper, this issue is addressed by means of an intercomparison of thirteen numerical codes for two-dimensional test cases with several performance metrics (PMs). These codes comprise a wide range of numerical approaches, spatialmore » and temporal discretization strategies, and computational efficiencies. Results suggest that the codes provide robust results for the test cases considered and that minor discrepancies are explained by computational precision. However, larger discrepancies are observed for some PMs resulting from differences in the governing equations, discretization issues, or in the freezing curve used by some codes.« less

Groundwater flow and heat transport for systems undergoing freeze-thaw: Intercomparison of numerical simulators for 2D test cases

NASA Astrophysics Data System (ADS)

Grenier, Christophe; Anbergen, Hauke; Bense, Victor; Chanzy, Quentin; Coon, Ethan; Collier, Nathaniel; Costard, François; Ferry, Michel; Frampton, Andrew; Frederick, Jennifer; Gonçalvès, Julio; Holmén, Johann; Jost, Anne; Kokh, Samuel; Kurylyk, Barret; McKenzie, Jeffrey; Molson, John; Mouche, Emmanuel; Orgogozo, Laurent; Pannetier, Romain; Rivière, Agnès; Roux, Nicolas; Rühaak, Wolfram; Scheidegger, Johanna; Selroos, Jan-Olof; Therrien, René; Vidstrand, Patrik; Voss, Clifford

2018-04-01

In high-elevation, boreal and arctic regions, hydrological processes and associated water bodies can be strongly influenced by the distribution of permafrost. Recent field and modeling studies indicate that a fully-coupled multidimensional thermo-hydraulic approach is required to accurately model the evolution of these permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require verification. This issue is addressed by means of an intercomparison of thirteen numerical codes for two-dimensional test cases with several performance metrics (PMs). These codes comprise a wide range of numerical approaches, spatial and temporal discretization strategies, and computational efficiencies. Results suggest that the codes provide robust results for the test cases considered and that minor discrepancies are explained by computational precision. However, larger discrepancies are observed for some PMs resulting from differences in the governing equations, discretization issues, or in the freezing curve used by some codes.

Groundwater flow and heat transport for systems undergoing freeze-thaw: Intercomparison of numerical simulators for 2D test cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grenier, Christophe; Anbergen, Hauke; Bense, Victor

In high-elevation, boreal and arctic regions, hydrological processes and associated water bodies can be strongly influenced by the distribution of permafrost. Recent field and modeling studies indicate that a fully-coupled multidimensional thermo-hydraulic approach is required to accurately model the evolution of these permafrost-impacted landscapes and groundwater systems. However, the relatively new and complex numerical codes being developed for coupled non-linear freeze-thaw systems require verification. Here in this paper, this issue is addressed by means of an intercomparison of thirteen numerical codes for two-dimensional test cases with several performance metrics (PMs). These codes comprise a wide range of numerical approaches, spatialmore » and temporal discretization strategies, and computational efficiencies. Results suggest that the codes provide robust results for the test cases considered and that minor discrepancies are explained by computational precision. However, larger discrepancies are observed for some PMs resulting from differences in the governing equations, discretization issues, or in the freezing curve used by some codes.« less

Extreme Rainfall from Hurricane Harvey (2017): Intercomparisons of WRF Simulations and Polarimetric Radar Fields

NASA Astrophysics Data System (ADS)

Yang, L.; Smith, J. A.; Liu, M.; Baeck, M. L.; Chaney, M. M.; Su, Y.

2017-12-01

Hurricane Harvey made landfall on 25 August 2017 and produced more than a meter of rain during a four-day period over eastern Texas, making it the wettest tropical cyclone on record in the United States. Extreme rainfall from Harvey was predominantly related to the dynamics and structure of outer rain bands. In this study, we provide details of the extreme rainfall produced by Hurricane Harvey. The principal research questions that motivate this study are: (1) what are the key microphysical properties of extreme rainfall from landfalling tropical cyclones and (2) what are the capabilities and deficiencies of existing bulk microphysics parameterizations from the physical models in capturing them. Our analyses are centered on intercomparisons of high-resolution simulations using the Weather Research and Forecasting (WRF) model and polarimetric radar fields from KHGX (Houston, Texas) WSR-88D. The WRF simulations accurately capture the track and intensity of Hurricane Harvey. Multi-rainband structure and its key evolution features are also well represented in the simulations. Two microphysics parameterizations (WSM6 and WDM6) are tested in this study. Radar reflectivity and differential reflectivity fields simulated by the WRF model are compared with polarimetric radar observations. An important feature for the extreme rainfall from Hurricane Harvey is the sharp boundary of spatial rainfall accumulation along the coast (with torrential rainfall distributed over Houston and its surrounding inland areas). We will examine the role of land-sea contrasts in dictating storm structure and evolution from both WRF simulations and polarimetric radar fields. Implications for improving hurricane rainfall forecasts and estimates will be provided.

ACTRIS non-methane hydrocarbon intercomparison experiment in Europe to support WMO-GAW and EMEP observation networks

NASA Astrophysics Data System (ADS)

Hoerger, C. C.; Werner, A.; Plass-Duelmer, C.; Reimann, S.; Eckart, E.; Steinbrecher, R.; Aalto, J.; Arduini, J.; Bonnaire, N.; Cape, J. N.; Colomb, A.; Connolly, R.; Diskova, J.; Dumitrean, P.; Ehlers, C.; Gros, V.; Hakola, H.; Hill, M.; Hopkins, J. R.; Jäger, J.; Junek, R.; Kajos, M. K.; Klemp, D.; Leuchner, M.; Lewis, A. C.; Locoge, N.; Maione, M.; Martin, D.; Michl, K.; Nemitz, E.; O'Doherty, S.; Pérez Ballesta, P.; Ruuskanen, T. M.; Sauvage, S.; Schmidbauer, N.; Spain, T. G.; Straube, E.; Vana, M.; Vollmer, M. K.; Wegener, R.; Wenger, A.

2014-10-01

The performance of 20 European laboratories involved in long-term non-methane hydrocarbon (NMHC) measurements within the framework of Global Atmosphere Watch (GAW) and European Monitoring and Evaluation Programme (EMEP) was assessed with respect to the ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) and GAW data quality objectives (DQOs). Compared to previous intercomparisons the DQOs of ACTRIS are much more demanding with deviations to a reference value of less than 5% and repeatability of better than 2% for mole fractions above 0.1 nmol mol-1. The participants were asked to measure both a 30 component NMHC mixture in nitrogen (NMHC_N2) at approximately 1 nmol mol-1 and whole air (NMHC_air), following a standardised operation procedure including zero- and calibration gas measurements. Furthermore, they had to report details on their instruments and they were asked to assess measurement uncertainties. The NMHCs were analysed either by gas chromatography-flame ionisation detection or gas chromatography-mass spectrometer methods. Most systems performed well for the NMHC_N2 measurements (88% of the reported values were within the GAW DQOs and even 58% within the ACTRIS DQOs). For NMHC_air generally more frequent and larger deviations to the assigned values were observed compared to NMHC_N2 (77% of the reported values were within the GAW DQOs, but only 48% within the ACTRIS DQOs). Important contributors to the poorer performance in NMHC_air compared to NMHC_N2 were a more complex matrix and a larger span of NMHC mole fractions (0.03-2.5 nmol mol-1). Issues, which affected both NMHC mixtures, are the usage of direct vs. two-step calibration, breakthrough of C2-C3 hydrocarbons, blank values in zero-gas measurements (especially for those systems using a Nafion® Dryer), adsorptive losses of aromatic compounds, and insufficient chromatographic resolution. Essential for high-quality results are experienced operators, a comprehensive quality

Comparison of microbiological diagnosis of urinary tract infection in young children by routine health service laboratories and a research laboratory: Diagnostic cohort study.

PubMed

Birnie, Kate; Hay, Alastair D; Wootton, Mandy; Howe, Robin; MacGowan, Alasdair; Whiting, Penny; Lawton, Michael; Delaney, Brendan; Downing, Harriet; Dudley, Jan; Hollingworth, William; Lisles, Catherine; Little, Paul; O'Brien, Kathryn; Pickles, Timothy; Rumsby, Kate; Thomas-Jones, Emma; Van der Voort, Judith; Waldron, Cherry-Ann; Harman, Kim; Hood, Kerenza; Butler, Christopher C; Sterne, Jonathan A C

2017-01-01

To compare the validity of diagnosis of urinary tract infection (UTI) through urine culture between samples processed in routine health service laboratories and those processed in a research laboratory. We conducted a prospective diagnostic cohort study in 4808 acutely ill children aged <5 years attending UK primary health care. UTI, defined as pure/predominant growth ≥105 CFU/mL of a uropathogen (the reference standard), was diagnosed at routine health service laboratories and a central research laboratory by culture of urine samples. We calculated areas under the receiver-operator curve (AUC) for UTI predicted by pre-specified symptoms, signs and dipstick test results (the "index test"), separately according to whether samples were obtained by clean catch or nappy (diaper) pads. 251 (5.2%) and 88 (1.8%) children were classified as UTI positive by health service and research laboratories respectively. Agreement between laboratories was moderate (kappa = 0.36; 95% confidence interval [CI] 0.29, 0.43), and better for clean catch (0.54; 0.45, 0.63) than nappy pad samples (0.20; 0.12, 0.28). In clean catch samples, the AUC was lower for health service laboratories (AUC = 0.75; 95% CI 0.69, 0.80) than the research laboratory (0.86; 0.79, 0.92). Values of AUC were lower in nappy pad samples (0.65 [0.61, 0.70] and 0.79 [0.70, 0.88] for health service and research laboratory positivity, respectively) than clean catch samples. The agreement of microbiological diagnosis of UTI comparing routine health service laboratories with a research laboratory was moderate for clean catch samples and poor for nappy pad samples and reliability is lower for nappy pad than for clean catch samples. Positive results from the research laboratory appear more likely to reflect real UTIs than those from routine health service laboratories, many of which (particularly from nappy pad samples) could be due to contamination. Health service laboratories should consider adopting procedures used in

Comparison of microbiological diagnosis of urinary tract infection in young children by routine health service laboratories and a research laboratory: Diagnostic cohort study

PubMed Central

Birnie, Kate; Hay, Alastair D.; Wootton, Mandy; Howe, Robin; MacGowan, Alasdair; Whiting, Penny; Lawton, Michael; Delaney, Brendan; Downing, Harriet; Dudley, Jan; Hollingworth, William; Lisles, Catherine; Little, Paul; O’Brien, Kathryn; Pickles, Timothy; Rumsby, Kate; Thomas-Jones, Emma; Van der Voort, Judith; Waldron, Cherry-Ann; Harman, Kim; Hood, Kerenza; Butler, Christopher C.; Sterne, Jonathan A. C.

2017-01-01

Objectives To compare the validity of diagnosis of urinary tract infection (UTI) through urine culture between samples processed in routine health service laboratories and those processed in a research laboratory. Population and methods We conducted a prospective diagnostic cohort study in 4808 acutely ill children aged <5 years attending UK primary health care. UTI, defined as pure/predominant growth ≥105 CFU/mL of a uropathogen (the reference standard), was diagnosed at routine health service laboratories and a central research laboratory by culture of urine samples. We calculated areas under the receiver-operator curve (AUC) for UTI predicted by pre-specified symptoms, signs and dipstick test results (the “index test”), separately according to whether samples were obtained by clean catch or nappy (diaper) pads. Results 251 (5.2%) and 88 (1.8%) children were classified as UTI positive by health service and research laboratories respectively. Agreement between laboratories was moderate (kappa = 0.36; 95% confidence interval [CI] 0.29, 0.43), and better for clean catch (0.54; 0.45, 0.63) than nappy pad samples (0.20; 0.12, 0.28). In clean catch samples, the AUC was lower for health service laboratories (AUC = 0.75; 95% CI 0.69, 0.80) than the research laboratory (0.86; 0.79, 0.92). Values of AUC were lower in nappy pad samples (0.65 [0.61, 0.70] and 0.79 [0.70, 0.88] for health service and research laboratory positivity, respectively) than clean catch samples. Conclusions The agreement of microbiological diagnosis of UTI comparing routine health service laboratories with a research laboratory was moderate for clean catch samples and poor for nappy pad samples and reliability is lower for nappy pad than for clean catch samples. Positive results from the research laboratory appear more likely to reflect real UTIs than those from routine health service laboratories, many of which (particularly from nappy pad samples) could be due to contamination. Health service

Productivity of Veterans Health Administration laboratories: a College of American Pathologists Laboratory Management Index Program (LMIP) study.

PubMed

Valenstein, Paul N; Wang, Edward; O'Donohue, Tom

2003-12-01

The Veterans Health Administration (VA) operates the largest integrated laboratory network in the United States. To assess whether the unique characteristics of VA laboratories impact efficiency of operations, we compared the productivity of VA and non-VA facilities. Financial and activity data were prospectively collected from 124 VA and 131 non-VA laboratories enrolled in the College of American Pathologists Laboratory Management Index Program (LMIP) during 2002. In addition, secular trends in 5 productivity ratios were calculated for VA and non-VA laboratories enrolled in LMIP from 1997 through 2002. Veterans Health Administration and non-VA facilities did not differ significantly in size. Inpatients accounted for a lower percentage of testing at VA facilities than non-VA facilities (21.7% vs 37.3%; P <.001). Technical staff at the median VA facility were paid more than at non-VA facilities (28.11/h dollars vs 22.60/h dollars, salaries plus benefits; P <.001), VA laboratories employed a smaller percentage of nontechnical staff (30.0% vs 41.9%; P <.001), and workers at VA laboratories worked less time per hour paid (85.5% vs 88.5%; P <.001). However, labor productivity was significantly higher at VA than at non-VA facilities (30 448 test results/total full-time equivalent (FTE)/y vs 19 260 results/total FTE; P <.001), resulting in lower labor expense per on-site test at VA sites than at non-VA sites (1.79 dollars/result vs 2.08 dollars/result; P <.001). Veterans Health Administration laboratories paid less per test for consumables (P =.003), depreciation, and maintenance than their non-VA counterparts (all P <.001), resulting in lower overall cost per on-site test result (2.64 dollars vs 3.40 dollars; P <.001). Cost per referred (sent-out) test did not differ significantly between the 2 groups. Analysis of 6-year trends showed significant increases in both VA (P <.001) and non-VA (P =.02) labor productivity (on-site tests/total FTE). Expenses at VA laboratories

Climate change impacts on tree ranges: model intercomparison facilitates understanding and quantification of uncertainty.

PubMed

Cheaib, Alissar; Badeau, Vincent; Boe, Julien; Chuine, Isabelle; Delire, Christine; Dufrêne, Eric; François, Christophe; Gritti, Emmanuel S; Legay, Myriam; Pagé, Christian; Thuiller, Wilfried; Viovy, Nicolas; Leadley, Paul

2012-06-01

Model-based projections of shifts in tree species range due to climate change are becoming an important decision support tool for forest management. However, poorly evaluated sources of uncertainty require more scrutiny before relying heavily on models for decision-making. We evaluated uncertainty arising from differences in model formulations of tree response to climate change based on a rigorous intercomparison of projections of tree distributions in France. We compared eight models ranging from niche-based to process-based models. On average, models project large range contractions of temperate tree species in lowlands due to climate change. There was substantial disagreement between models for temperate broadleaf deciduous tree species, but differences in the capacity of models to account for rising CO(2) impacts explained much of the disagreement. There was good quantitative agreement among models concerning the range contractions for Scots pine. For the dominant Mediterranean tree species, Holm oak, all models foresee substantial range expansion. © 2012 Blackwell Publishing Ltd/CNRS.

Intercomparisons of Marine Boundary Layer Cloud Properties from the ARM CAP-MBL Campaign and Two MODIS Cloud Products

NASA Technical Reports Server (NTRS)

Zhang, Zhibo; Dong, Xiquan; Xi, Baike; Song, Hua; Ma, Po-Lun; Ghan, Steven J.; Platnick, Steven; Minnis, Patrick

2017-01-01

From April 2009 to December 2010, the Department of Energy (DOE) 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 inter-comparison 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 (AMF) and two Moderate Resolution Spectroradiometer (MODIS) cloud products (GSFC-MODIS and CERES-MODIS). A total of 63 daytime single-layer MBL cloud cases are selected for inter-comparison. Comparison of collocated retrievals indicates that the two MODIS cloud products agree well on both COT and CER retrievals, with the correlation coefficient R greater than 0.95 despite their significant difference in spatial sampling. In both MODIS products, the CER retrievals based on the 2.1 micrometers band (CER(sub 2.1)) is significantly smaller than that based on the 3.7 micrometers band (CER(sub 3.7)). 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 CER(sub 3.7) and CER(sub 2.1) retrievals have a lower correlation (R is approximately 0.5) with the ground-based retrievals. For the 63 selected cases, they are on average larger than ground observations by about 1.5 micrometers and 3.0 micrometers, respectively. Taking into account that the MODIS CER retrievals are only sensitive to cloud top reduces the bias only by 0.5 micrometers.

Intercomparisons of marine boundary layer cloud properties from the ARM CAP-MBL campaign and two MODIS cloud products

NASA Astrophysics Data System (ADS)

Zhang, Zhibo; Dong, Xiquan; Xi, Baike; Song, Hua; Ma, Po-Lun; Ghan, Steven J.; Platnick, Steven; Minnis, Patrick

2017-02-01

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 µm band (CER2.1) are significantly larger than those based on the 3.7 µm 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 0.5) with the ground-based retrievals. For the 63 selected cases, they are on average larger than ground observations by about 1.5 µm and 3.0 µm, respectively. Taking into account that the MODIS CER retrievals are only sensitive to cloud top reduces the bias only by 0.5 µm.

FIRST EURADOS INTERCOMPARISON EXERCISE OF EYE LENS DOSEMETERS FOR MEDICAL APPLICATIONS.

PubMed

Clairand, I; Ginjaume, M; Vanhavere, F; Carinou, E; Daures, J; Denoziere, M; Silva, E H; Roig, M; Principi, S; Van Rycheghem, L

2016-09-01

In the context of the decrease in the eye lens dose limit for occupational exposure to 20 mSv per year stated by the recent revision of the European Basic Safety Standards Directive 2013/59/EURATOM, the European Radiation Dosimetry Group (EURADOS) has organised in 2014, for the first time, an intercomparison exercise for eye lens dosemeters. The main objective was to assess the capabilities of the passive eye lens dosemeters currently in use in Europe for occupational monitoring in medical fields. A total of 20 European individual monitoring services from 15 different countries have participated. The dosemeters provided by the participants were all composed of thermoluminescent detectors, of various types and designs. The irradiations were carried out with several photon fields chosen to cover the energy and angle ranges encountered in medical workplace. Participants were asked to report the doses in terms of Hp(3) using their routine protocol. The results provided by each participant were compared with the reference delivered doses. All the results were anonymously analysed. Results are globally satisfactory since, among the 20 participants, 17 were able to provide 90 % of their response in accordance with the ISO 14146 standard requirements. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Aircraft/island/ship/satellite intercomparison: Preliminary results from July 16, 1987

NASA Technical Reports Server (NTRS)

Hanson, Howard P.; Davidson, Ken; Gerber, Herman; Khalsa, Siri Jodha Singh; Kloesel, Kevin A.; Schwiesow, Ronald; Snider, Jack B.; Wielicki, Bruce M.; Wylie, Donald P.

1990-01-01

The First ISCCP Regional Experiment (FIRE) objective of validating and improving satellite algorithms for inferring cloud properties from satellite radiances was one of the central motivating factors in the design of the specific field experimental strategies used in the July, 1987 marine stratocumulus intensive field observations (IFO). The in situ measuring platforms were deployed to take maximum advantage of redundant measurements (for intercomparison of the in situ sensors) and to provide optimal coverage within satellite images. One of the most ambitious of these strategies was the attempt to coordinate measurements from San Nicolas Island (SNI), the R/V Pt. Sur, the meteorological aircraft, and the satellites. For the most part, this attempt was frustrated by flight restrictions in the vicinity of SNI. The exception was the mission of July 16, 1987, which achieved remarkable success in the coordination of the platforms. This presentation concerns operations conducted by the National Center for Atmospheric Research (NCAR) Electra and how data from the Electra can be integrated with and compared to data from the Pt. Sur, SNI, and the satellites. The focus is on the large-scale, integrated picture of the conditions on July 16 from the perspective of the Electra's flight operations.

2014 ICHLNRRA intercomparison of radon/thoron gas and radon short-lived decay products measuring instruments in the NRPI Prague.

PubMed

Jílek, K; Timková, J

2015-06-01

During the Eighth International Conference on High Levels of Natural Radiation and Radon Areas held in autumn 2014 at Prague, the third intercomparison of radon/thoron gas and radon short-lived decay products measurement instruments was organised by and held at the Natural Radiation Division of the National Radiation Protection Institute (NRPI; SÚRO v.v.i.) in Prague. The intercomparison was newly focussed also on continuous monitors with active sampling adapters capable to distinguish radon/thoron gas in their mix field.The results of radon gas measurements carried out in the big NRPI radon chamber indicated very well an average deviation of up to 5 % from the reference NRPI value for 80 % of all the exposed instruments. The results of equilibrium equivalent concentration continuous monitors indicated an average deviation of up to 5 % from the reference NRPI value for 40 % of all the exposed instruments and their ~8-10 % shift compared with the NRPI. The results of investigated ambient conditions upon response of exposed continuous monitors indicated influence of aerosol changes upon response of radon monitors with an active air sampling adapters through the filter, only. The exposures of both radon/thoron gas discriminative continuous monitors and passive detectors have been indicated inconsistent results: on one hand, their excellent agreement up to several per cent for both the gases, and on the other hand, systematic unsatisfactory differences up to 40 %. Additional radon/thoron exercises are recommended to improve both the instruments themselves and quality of their operators. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

OMIP contribution to CMIP6: experimental and diagnostic protocol for the physical component of the Ocean Model Intercomparison Project

NASA Astrophysics Data System (ADS)

Griffies, Stephen M.; Danabasoglu, Gokhan; Durack, Paul J.; Adcroft, Alistair J.; Balaji, V.; Böning, Claus W.; Chassignet, Eric P.; Curchitser, Enrique; Deshayes, Julie; Drange, Helge; Fox-Kemper, Baylor; Gleckler, Peter J.; Gregory, Jonathan M.; Haak, Helmuth; Hallberg, Robert W.; Heimbach, Patrick; Hewitt, Helene T.; Holland, David M.; Ilyina, Tatiana; Jungclaus, Johann H.; Komuro, Yoshiki; Krasting, John P.; Large, William G.; Marsland, Simon J.; Masina, Simona; McDougall, Trevor J.; Nurser, A. J. George; Orr, James C.; Pirani, Anna; Qiao, Fangli; Stouffer, Ronald J.; Taylor, Karl E.; Treguier, Anne Marie; Tsujino, Hiroyuki; Uotila, Petteri; Valdivieso, Maria; Wang, Qiang; Winton, Michael; Yeager, Stephen G.

2016-09-01

The Ocean Model Intercomparison Project (OMIP) is an endorsed project in the Coupled Model Intercomparison Project Phase 6 (CMIP6). OMIP addresses CMIP6 science questions, investigating the origins and consequences of systematic model biases. It does so by providing a framework for evaluating (including assessment of systematic biases), understanding, and improving ocean, sea-ice, tracer, and biogeochemical components of climate and earth system models contributing to CMIP6. Among the WCRP Grand Challenges in climate science (GCs), OMIP primarily contributes to the regional sea level change and near-term (climate/decadal) prediction GCs.OMIP provides (a) an experimental protocol for global ocean/sea-ice models run with a prescribed atmospheric forcing; and (b) a protocol for ocean diagnostics to be saved as part of CMIP6. We focus here on the physical component of OMIP, with a companion paper (Orr et al., 2016) detailing methods for the inert chemistry and interactive biogeochemistry. The physical portion of the OMIP experimental protocol follows the interannual Coordinated Ocean-ice Reference Experiments (CORE-II). Since 2009, CORE-I (Normal Year Forcing) and CORE-II (Interannual Forcing) have become the standard methods to evaluate global ocean/sea-ice simulations and to examine mechanisms for forced ocean climate variability. The OMIP diagnostic protocol is relevant for any ocean model component of CMIP6, including the DECK (Diagnostic, Evaluation and Characterization of Klima experiments), historical simulations, FAFMIP (Flux Anomaly Forced MIP), C4MIP (Coupled Carbon Cycle Climate MIP), DAMIP (Detection and Attribution MIP), DCPP (Decadal Climate Prediction Project), ScenarioMIP, HighResMIP (High Resolution MIP), as well as the ocean/sea-ice OMIP simulations.

Virtual Laboratory "vs." Traditional Laboratory: Which Is More Effective for Teaching Electrochemistry?

ERIC Educational Resources Information Center

Hawkins, Ian; Phelps, Amy J.

2013-01-01

The use of virtual laboratories has become an increasing issue regarding science laboratories due to the increasing cost of hands-on laboratories, and the increase in distance education. Recent studies have looked at the use of virtual tools for laboratory to be used as supplements to the regular hands-on laboratories but many virtual tools have…

Laboratory experiments in the study of the chemistry of the outer planets.

PubMed

Scattergood, T W

1987-01-01

The investigation of chemical evolution of bodies in our solar system has, in the past, included observations, theoretical modeling, and laboratory simulations. Of these programs, the last one has been the most criticized due to the inherent difficulties in accurately recreating alien environments in the laboratory. Processes such as wall reactions and changes in chemistry due to difficulties in achieving realistic conditions of temperature, pressure, composition, and energy flux may yield results which are not truly representative of the systems being modeled. However, many laboratory studies have been done which have yielded data useful in planetary science. Gross simulations of atmospheric chemistry have placed constraints on the nature of complex molecules expected in planetary atmospheres. More precise studies of specific chemical processes have provided information about the sources and properties of product gases and aerosols. Determinations of basic properties such as spectral features and reaction rate constants yield data useful in the interpretation of observations and in computational modeling. Alone, and in conjunction with modeling, laboratory experiments will continue to be used to further our understanding of the outer solar system, and some experiments that need to be done are listed.

Laboratory Needs for Interstellar Ice Studies

NASA Astrophysics Data System (ADS)

Boogert, Abraham C. A.

2012-05-01

A large fraction of the molecules in dense interstellar and circumstellar environments is stored in icy grain mantles. The mantles are formed by a complex interplay between chemical and physical processes. Key questions on the accretion and desorption processes and the chemistry on the grain surfaces and within the icy mantles can only be answered by laboratory experiments. Recent infrared (2-30 micron) spectroscopic surveys of large samples of Young Stellar Objects (YSOs) and background stars tracing quiescent cloud material have shown that the ice band profiles and depths vary considerably as a function of environment. Using laboratory spectra in the identification process, it is clear that a rather complex mixture of simple species (CH3OH, CO2, H2O, CO) exists even in the quiescent cloud phase. Variations of the local physical conditions (CO freeze out) and time scales (CH3OH formation) appear to be key factors in the observed variations. Sublimation and thermal processing dominate as YSOs heat their environments. The identification of several ice absorption features is still disputed. I will outline laboratory work (e.g., on salts, PAHs, and aliphatic hydrocarbons) needed to further constrain the ice band identification as well as the thermal and chemical history of the carriers. Such experiments will also be essential to interpret future high spectral resolution SOFIA and JWST observations.

Exploring the links between quality assurance and laboratory resources. An audit-based study.

PubMed

Singh, Navjeevan; Panwar, Aru; Masih, Vipin Fazal; Arora, Vinod K; Bhatia, Arati

2003-01-01

To investigate and rectify the problems related to Ziehl-Neelsen (Z-N) staining in a cytology laboratory in the context of quality assurance. An audit based quality assurance study of 1,421 patients with clinical diagnoses of tubercular lymphadenopathy who underwent fine needle aspiration cytology. Data from 8 months were audited (group 1). Laboratory practices related to selection of smears for Z-N staining were studied. A 2-step corrective measure based on results of the audit was introduced for 2 months (group 2). Results were subjected to statistical analysis using the chi 2 test. Of 1,172 patients in group 1,368 had diagnoses other than tuberculosis. Overall acid-fast bacillus (AFB) positivity was 42%. AFB positivity in 249 patients in group 2 was 89% (P < .0001). Several issues in the laboratory are linked to quality assurance. Solving everyday problems can have far-reaching benefits for the performance of laboratory personnel, resources and work flow.

How do laboratory technicians perceive their role in the tuberculosis diagnostic process? A cross-sectional study among laboratory technicians in health centers of Central Java Province, Indonesia.

PubMed

Widjanarko, Bagoes; Widyastari, Dyah Anantalia; Martini, Martini; Ginandjar, Praba

2016-01-01

Detection of acid-fast bacilli in respiratory specimens serves as an initial pulmonary tuberculosis (TB) diagnosis. Laboratories are the essential and fundamental part of all health systems. This study aimed to describe how laboratory technicians perceived their own self and work. This included perceived self-efficacy, perceived role, perceived equipment availability, perceived procedures, perceived reward and job, and perceived benefit of health education, as well as level of knowledge and attitudes related to work performance of laboratory technicians. This was a cross-sectional quantitative study involving 120 laboratory technicians conducted in Central Java. Interviews and observation were conducted to measure performance and work-related variables. Among 120 laboratory technicians, 43.3% showed fairly good performance. They complied with 50%-75% of all procedures, including sputum collection, laboratory tools utilization, sputum smearing, staining, smear examination, grading of results, and universal precaution practice. Perceived role, perceived self-efficacy, and knowledge of laboratory procedures were significantly correlated to performance, besides education and years of working as a laboratory technician. Perceived equipment availability was also significantly correlated to performance after the education variable was controlled. Most of the laboratory technicians believed that they have an important role in TB patients' treatment and should display proper self-efficacy in performing laboratory activities. The result may serve as a basic consideration to develop a policy for enhancing motivation of laboratory technicians in order to improve the TB control program.

How do laboratory technicians perceive their role in the tuberculosis diagnostic process? A cross-sectional study among laboratory technicians in health centers of Central Java Province, Indonesia

PubMed Central

Widjanarko, Bagoes; Widyastari, Dyah Anantalia; Martini, Martini; Ginandjar, Praba

2016-01-01

Purpose Detection of acid-fast bacilli in respiratory specimens serves as an initial pulmonary tuberculosis (TB) diagnosis. Laboratories are the essential and fundamental part of all health systems. This study aimed to describe how laboratory technicians perceived their own self and work. This included perceived self-efficacy, perceived role, perceived equipment availability, perceived procedures, perceived reward and job, and perceived benefit of health education, as well as level of knowledge and attitudes related to work performance of laboratory technicians. Methods This was a cross-sectional quantitative study involving 120 laboratory technicians conducted in Central Java. Interviews and observation were conducted to measure performance and work-related variables. Results Among 120 laboratory technicians, 43.3% showed fairly good performance. They complied with 50%–75% of all procedures, including sputum collection, laboratory tools utilization, sputum smearing, staining, smear examination, grading of results, and universal precaution practice. Perceived role, perceived self-efficacy, and knowledge of laboratory procedures were significantly correlated to performance, besides education and years of working as a laboratory technician. Perceived equipment availability was also significantly correlated to performance after the education variable was controlled. Conclusion Most of the laboratory technicians believed that they have an important role in TB patients’ treatment and should display proper self-efficacy in performing laboratory activities. The result may serve as a basic consideration to develop a policy for enhancing motivation of laboratory technicians in order to improve the TB control program. PMID:27660502

Intercomparison between CMIP5 model and MODIS satellite-retrieved data of aerosol optical depth, cloud fraction, and cloud-aerosol interactions

NASA Astrophysics Data System (ADS)

Sockol, Alyssa; Small Griswold, Jennifer D.

2017-08-01

Aerosols are a critical component of the Earth's atmosphere and can affect the climate of the Earth through their interactions with solar radiation and clouds. Cloud fraction (CF) and aerosol optical depth (AOD) at 550 nm from the Moderate Resolution Imaging Spectroradiometer (MODIS) are used with analogous cloud and aerosol properties from Historical Phase 5 of the Coupled Model Intercomparison Project (CMIP5) model runs that explicitly include anthropogenic aerosols and parameterized cloud-aerosol interactions. The models underestimate AOD by approximately 15% and underestimate CF by approximately 10% overall on a global scale. A regional analysis is then used to evaluate model performance in two regions with known biomass burning activity and absorbing aerosol (South America (SAM) and South Africa (SAF)). In SAM, the models overestimate AOD by 4.8% and underestimate CF by 14%. In SAF, the models underestimate AOD by 35% and overestimate CF by 13.4%. Average annual cycles show that the monthly timing of AOD peaks closely match satellite data in both SAM and SAF for all except the Community Atmosphere Model 5 and Geophysical Fluid Dynamics Laboratory (GFDL) models. Monthly timing of CF peaks closely match for all models (except GFDL) for SAM and SAF. Sorting monthly averaged 2° × 2.5° model or MODIS CF as a function of AOD does not result in the previously observed "boomerang"-shaped CF versus AOD relationship characteristic of regions with absorbing aerosols from biomass burning. Cloud-aerosol interactions, as observed using daily (or higher) temporal resolution data, are not reproducible at the spatial or temporal resolution provided by the CMIP5 models.

The thermal structure of the Venus atmosphere: Intercomparison of Venus Express and ground based observations of vertical temperature and density profiles✰

NASA Astrophysics Data System (ADS)

Limaye, Sanjay S.; Lebonnois, Sebastien; Mahieux, Arnaud; Pätzold, Martin; Bougher, Steven; Bruinsma, Sean; Chamberlain, Sarah; Clancy, R. Todd; Gérard, Jean-Claude; Gilli, Gabriella; Grassi, Davide; Haus, Rainer; Herrmann, Maren; Imamura, Takeshi; Kohler, Erika; Krause, Pia; Migliorini, Alessandra; Montmessin, Franck; Pere, Christophe; Persson, Moa; Piccialli, Arianna; Rengel, Miriam; Rodin, Alexander; Sandor, Brad; Sornig, Manuela; Svedhem, Håkan; Tellmann, Silvia; Tanga, Paolo; Vandaele, Ann C.; Widemann, Thomas; Wilson, Colin F.; Müller-Wodarg, Ingo; Zasova, Ludmila

2017-09-01

The Venus International Reference Atmosphere (VIRA) model contains tabulated values of temperature and number densities obtained by the experiments on the Venera entry probes, Pioneer Venus Orbiter and multi-probe missions in the 1980s. The instruments on the recent Venus Express orbiter mission generated a significant amount of new observational data on the vertical and horizontal structure of the Venus atmosphere from 40 km to about 180 km altitude from April 2006 to November 2014. Many ground based experiments have provided data on the upper atmosphere (90-130 km) temperature structure since the publication of VIRA in 1985. The "Thermal Structure of the Venus Atmosphere" Team was supported by the International Space Studies Institute (ISSI), Bern, Switzerland, from 2013 to 2015 in order to combine and compare the ground-based observations and the VEx observations of the thermal structure as a first step towards generating an updated VIRA model. Results of this comparison are presented in five latitude bins and three local time bins by assuming hemispheric symmetry. The intercomparison of the ground-based and VEx results provides for the first time a consistent picture of the temperature and density structure in the 40 km-180 km altitude range. The Venus Express observations have considerably increased our knowledge of the Venus atmospheric thermal structure above ∼40 km and provided new information above 100 km. There are, however, still observational gaps in latitude and local time above certain regions. Considerable variability in the temperatures and densities is seen above 100 km but certain features appear to be systematically present, such as a succession of warm and cool layers. Preliminary modeling studies support the existence of such layers in agreement with a global scale circulation. The intercomparison focuses on average profiles but some VEx experiments provide sufficient global coverage to identify solar thermal tidal components. The differences

Development of performance properties of ternary mixtures : laboratory study on concrete.

DOT National Transportation Integrated Search

2011-03-01

This research project is a comprehensive study of how supplementary cementitious materials (SCMs) can be used to : improve the performance of concrete mixtures. This report summarizes the findings of the Laboratory Study on Concrete : phase of this w...

Intercomparison of Desert Dust Optical Depth from Satellite Measurements

NASA Technical Reports Server (NTRS)

Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.;

Field Intercomparison of Six Sifferent Three-dimensional Sonic Anemometers

NASA Astrophysics Data System (ADS)

Zeeman, M. J.; Mauder, M.

2016-12-01

Although sonic anemometers have been used extensively for several decades in micrometeorological and ecological research, there is still some scientific debate about the measurement uncertainty of these instruments. This is due to the fact that an absolute reference for the measurement of turbulent wind fluctuations in the free atmosphere does not exist. In view of this lack we have conducted a field intercomparison experiment of six commonly used sonic anemometers from four major manufacturers. The models included Campbell CSAT3, Gill HS-50 and R3, METEK uSonic-3 Omni, R.M. Young 81000 and 81000RE. The experiment was conducted over a meadow at the TERENO/ICOS site De-Fen in southern Germany over a period of 16 days in June of 2016 in preparation of the ScaleX campaign. The measurement height was 3 m for all sensors, which were separated by 9 m from each other, each on its own tripod, in order to limit contamination of the turbulence measurements by neighbouring structures as much as possible. Moreover, the data were filtered for potentially disturbed wind sectors, and the high-frequency data from all instruments were treated with the same post-processing algorithm. In this presentation, we compare the results for various turbulence statistics from all sensors. These include mean horizontal wind speed, standard deviations of vertical wind velocity and sonic temperature, friction velocity and the covariance between vertical wind velocity and sonic temperature. Quantitative measures of uncertainty, such as bias and comparability are derived from these results.

Transferability and within- and between-laboratory reproducibilities of EpiSensA for predicting skin sensitization potential in vitro: A ring study in three laboratories.

PubMed

Mizumachi, Hideyuki; Sakuma, Megumi; Ikezumi, Mayu; Saito, Kazutoshi; Takeyoshi, Midori; Imai, Noriyasu; Okutomi, Hiroko; Umetsu, Asami; Motohashi, Hiroko; Watanabe, Mika; Miyazawa, Masaaki

2018-05-03

The epidermal sensitization assay (EpiSensA) is an in vitro skin sensitization test method based on gene expression of four markers related to the induction of skin sensitization; the assay uses commercially available reconstructed human epidermis. EpiSensA has exhibited an accuracy of 90% for 72 chemicals, including lipophilic chemicals and pre-/pro-haptens, when compared with the results of the murine local lymph node assay. In this work, a ring study was performed by one lead and two naive laboratories to evaluate the transferability, as well as within- and between-laboratory reproducibilities, of EpiSensA. Three non-coded chemicals (two lipophilic sensitizers and one non-sensitizer) were tested for the assessment of transferability and 10 coded chemicals (seven sensitizers and three non-sensitizers, including four lipophilic chemicals) were tested for the assessment of reproducibility. In the transferability phase, the non-coded chemicals (two sensitizers and one non-sensitizer) were correctly classified at the two naive laboratories, indicating that the EpiSensA protocol was transferred successfully. For the within-laboratory reproducibility, the data generated with three coded chemicals tested in three independent experiments in each laboratory gave consistent predictions within laboratories. For the between-laboratory reproducibility, 9 of the 10 coded chemicals tested once in each laboratory provided consistent predictions among the three laboratories. These results suggested that EpiSensA has good transferability, as well as within- and between-laboratory reproducibility. Copyright © 2018 John Wiley & Sons, Ltd.

Laboratory studies of cometary ice analogues

NASA Astrophysics Data System (ADS)

Schmitt, B.; Espinasse, S.; Grim, R. J. A.; Greenberg, J. M.; Klinger, J.

1989-12-01

Laboratory studies were performed in order to simulate the physico-chemical processes that are likely to occur in the near surface layers of short and intermediate period comets. Pure H2O ice as well as CO:H2O, CO2:H2O, CH4:H2O, CO:CO2:H2O, and NH3:H2O ice mixtures were studied in the temperature range between 10 and 180 K. The evolution of the composition of ice mixtures, the crystallization of H2O ice as well as the formation and decompostion of clathrate hydrate by different processes were studied as a function of temperature and time. Using the results together with numerical modeling, predictions are made about the survival of amorphous ice, CO, CO2, CH4, and NH3 in the near surface layers of short period comets. The likeliness of finding clathrate and molecular hydrates is discussed. It is proposed that the analytical methods developed here could be fruitfully adapted to the analysis of returned comet samples.

A Feasibility Study for Mobile Marketing and Distribution Occupational Laboratories in North Dakota.

ERIC Educational Resources Information Center

Kohns, Donald P.

A study determined the feasibility of a mobile laboratory for marketing and distribution in North Dakota. It attempted to answer four questions: (1) What types of staffing, equipment, curriculum, and delivery systems are presently being utilized in mobile laboratories throughout the nation? (2) What significant information obtained from mobile…

Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) experimental design and organization

DOE PAGES

Eyring, Veronika; Bony, Sandrine; Meehl, Gerald A.; ...

2016-05-26

By coordinating the design and distribution of global climate model simulations of the past, current, and future climate, the Coupled Model Intercomparison Project (CMIP) has become one of the foundational elements of climate science. However, the need to address an ever-expanding range of scientific questions arising from more and more research communities has made it necessary to revise the organization of CMIP. After a long and wide community consultation, a new and more federated structure has been put in place. It consists of three major elements: (1) a handful of common experiments, the DECK (Diagnostic, Evaluation and Characterization of Klima) andmore » CMIP historical simulations (1850–near present) that will maintain continuity and help document basic characteristics of models across different phases of CMIP; (2) common standards, coordination, infrastructure, and documentation that will facilitate the distribution of model outputs and the characterization of the model ensemble; and (3) an ensemble of CMIP-Endorsed Model Intercomparison Projects (MIPs) that will be specific to a particular phase of CMIP (now CMIP6) and that will build on the DECK and CMIP historical simulations to address a large range of specific questions and fill the scientific gaps of the previous CMIP phases. The DECK and CMIP historical simulations, together with the use of CMIP data standards, will be the entry cards for models participating in CMIP. Participation in CMIP6-Endorsed MIPs by individual modelling groups will be at their own discretion and will depend on their scientific interests and priorities. With the Grand Science Challenges of the World Climate Research Programme (WCRP) as its scientific backdrop, CMIP6 will address three broad questions: – How does the Earth system respond to forcing? – What are the origins and consequences of systematic model biases? – How can we assess future climate changes given internal climate variability, predictability, and

Sediment laboratory quality-assurance project: studies of methods and materials

USGS Publications Warehouse

Gordon, J.D.; Newland, C.A.; Gray, J.R.

2001-01-01

In August 1996 the U.S. Geological Survey initiated the Sediment Laboratory Quality-Assurance project. The Sediment Laboratory Quality Assurance project is part of the National Sediment Laboratory Quality-Assurance program. This paper addresses the fmdings of the sand/fme separation analysis completed for the single-blind reference sediment-sample project and differences in reported results between two different analytical procedures. From the results it is evident that an incomplete separation of fme- and sand-size material commonly occurs resulting in the classification of some of the fme-size material as sand-size material. Electron microscopy analysis supported the hypothesis that the negative bias for fme-size material and the positive bias for sand-size material is largely due to aggregation of some of the fine-size material into sand-size particles and adherence of fine-size material to the sand-size grains. Electron microscopy analysis showed that preserved river water, which was low in dissolved solids, specific conductance, and neutral pH, showed less aggregation and adhesion than preserved river water that was higher in dissolved solids and specific conductance with a basic pH. Bacteria were also found growing in the matrix, which may enhance fme-size material aggregation through their adhesive properties. Differences between sediment-analysis methods were also investigated as pan of this study. Suspended-sediment concentration results obtained from one participating laboratory that used a total-suspended solids (TSS) method had greater variability and larger negative biases than results obtained when this laboratory used a suspended-sediment concentration method. When TSS methods were used to analyze the reference samples, the median suspended sediment concentration percent difference was -18.04 percent. When the laboratory used a suspended-sediment concentration method, the median suspended-sediment concentration percent difference was -2

[Comparability study of analytical results between a group of clinical laboratories].

PubMed

Alsius-Serra, A; Ballbé-Anglada, M; López-Yeste, M L; Buxeda-Figuerola, M; Guillén-Campuzano, E; Juan-Pereira, L; Colomé-Mallolas, C; Caballé-Martín, I

2015-01-01

To describe the study of the comparability of the measurements levels of biological tests processed in biochemistry in Catlab's 4 laboratories. Quality requirements, coefficients of variation and total error (CV% and TE %) were established. Controls were verified with the precision requirements (CV%) in each test and each individual laboratory analyser. Fresh serum samples were used for the comparability study. The differences were analysed using a Microsoft Access® application that produces modified Bland-Altman plots. The comparison of 32 biological parameters that are performed in more than one laboratory and/or analyser generated 306 Bland-Altman graphs. Of these, 101 (33.1%) fell within the accepted range of values based on biological variability, and 205 (66.9%) required revision. Data were re-analysed based on consensus minimum specifications for analytical quality (consensus of the Asociación Española de Farmacéuticos Analistas (AEFA), the Sociedad Española de Bioquímica Clínica y Patología Molecular (SEQC), the Asociación Española de Biopatología Médica (AEBM) and the Sociedad Española de Hematología y Hemoterapia (SEHH), October 2013). With the new specifications, 170 comparisons (56%) fitted the requirements and 136 (44%) required additional review. Taking into account the number of points that exceeded the requirement, random errors, range of results in which discrepancies were detected, and range of clinical decision, it was shown that the 44% that required review were acceptable, and the 32 tests were comparable in all laboratories and analysers. The analysis of the results showed that the consensus requirements of the 4 scientific societies were met. However, each laboratory should aim to meet stricter criteria for total error. Copyright © 2015 SECA. Published by Elsevier Espana. All rights reserved.

Preparation of a sewage sludge laboratory quality control material for butyltin compounds and their determination by isotope-dilution mass spectrometry.

PubMed

Zuliani, Tea; Milačič, Radmila; Ščančar, Janez

2012-05-01

The characterisation of a laboratory quality control material (QCM) for dibutyltin (DBT) and tributyltin (TBT) in sewage sludge is described. The reference values were determined by the use of two different types of isotope-dilution mass spectrometry: gas chromatography-mass spectrometry and gas chromatography-inductively coupled plasma mass spectrometry. To avoid possible analytical errors such as non-quantitative extraction and species degradation during sample preparation, different extraction methods were tested (microwave- and ultrasound-assisted extraction and mechanical stirring). The reference values were based on the unweighted means of results from the homogenisation and characterisation studies. The reference values obtained were 1,553 ± 87 and 534 ± 38 ng Sn g(-1) for DBT and TBT, respectively. In the uncertainty budget estimation, the sample inhomogeneity and between-method imprecision were taken into account. The concentrations of DBT and TBT in QCM are similar to those in the harbour sediment certified reference material PACS-2. Likewise, the levels of DBT and TBT are in the range of these compounds normally present in sewage sludge worldwide. In the future, the QCM will be used for an intercomparison study on DBT and TBT in sewage sludge, and as a day-to-day QCM during studies concerning the application of sewage sludge as an additive to artificial soil or as a raw material in civil engineering construction.

Laboratory studies with the systemic trichononacide, metronidazole

PubMed Central

Jennison, R. F.; Stenton, P.; Watt, Leslie

1961-01-01

Laboratory studies with the trichomonacidal agent, metronidazole, show that 66 strains of T. vaginalis were killed in three days by concentrations of 0·0625 μg./ml. to 1 μg./ml. Estimations of serum and urine levels in nine volunteers, the serum levels in 31 women, and the urine levels in 33 women show that metronidazole is rapidly absorbed and excreted in high concentration in the urine. Development of resistance to metronidazole by T. vaginalis has not been demonstrated either in vivo or in vitro. No toxic effect was demonstrated in the blood, liver, or kidney. PMID:13789871

DCMIP2016: a review of non-hydrostatic dynamical core design and intercomparison of participating models

NASA Astrophysics Data System (ADS)

Ullrich, Paul A.; Jablonowski, Christiane; Kent, James; Lauritzen, Peter H.; Nair, Ramachandran; Reed, Kevin A.; Zarzycki, Colin M.; Hall, David M.; Dazlich, Don; Heikes, Ross; Konor, Celal; Randall, David; Dubos, Thomas; Meurdesoif, Yann; Chen, Xi; Harris, Lucas; Kühnlein, Christian; Lee, Vivian; Qaddouri, Abdessamad; Girard, Claude; Giorgetta, Marco; Reinert, Daniel; Klemp, Joseph; Park, Sang-Hun; Skamarock, William; Miura, Hiroaki; Ohno, Tomoki; Yoshida, Ryuji; Walko, Robert; Reinecke, Alex; Viner, Kevin

2017-12-01

Atmospheric dynamical cores are a fundamental component of global atmospheric modeling systems and are responsible for capturing the dynamical behavior of the Earth's atmosphere via numerical integration of the Navier-Stokes equations. These systems have existed in one form or another for over half of a century, with the earliest discretizations having now evolved into a complex ecosystem of algorithms and computational strategies. In essence, no two dynamical cores are alike, and their individual successes suggest that no perfect model exists. To better understand modern dynamical cores, this paper aims to provide a comprehensive review of 11 non-hydrostatic dynamical cores, drawn from modeling centers and groups that participated in the 2016 Dynamical Core Model Intercomparison Project (DCMIP) workshop and summer school. This review includes a choice of model grid, variable placement, vertical coordinate, prognostic equations, temporal discretization, and the diffusion, stabilization, filters, and fixers employed by each system.

The case for investigating social context in laboratory studies of smoking.

PubMed

Dimoff, John D; Sayette, Michael A

2017-03-01

With increasing frequency, addiction is conceived of as a brain disease, and such accounts seem especially pertinent with regard to the rapid delivery of nicotine to the brain via cigarette smoke. Moreover, drug administration trials (cigarette puffs) suggest that the behavior of smoking becomes automatized, with individuals developing prototypical approaches to smoking a cigarette. Compared with presumably more social activities, such as drinking alcohol, there may be little opportunity for social processes to influence smoking behavior. However, survey research examining smoking motivation often reveals a broadly defined 'social' factor and field research suggests that social context does influence smoking. We posit that laboratory smoking research has largely ignored social contextual factors that may help to understand better the precise mechanisms underlying smoking behavior and smoking motivation. We reviewed laboratory studies examining the effect of social context (operationalized as modeling) on smoking behavior. Studies were identified by searching PsychInfo and Medline using the following keywords: smoking, nicotine, tobacco, cigarette, consumption, topography, puff, smoking behavior, cigarettes smoked, modeling, imitation, social context, social influence and peer pressure. The reference and citation lists of these studies were then searched to identify additional studies. Few laboratory smoking studies target social context. Those few studies indicate that smoking behavior can be influenced by the presence of others. There is also some evidence that social context influences the effects of smoking as well as processes related to self-perception and self-regulation that reinforce smoking and hamper smoking cessation efforts. © 2016 Society for the Study of Addiction.

Detection of Cryptosporidium and Giardia in clinical laboratories in Europe--a comparative study.

PubMed

Manser, M; Granlund, M; Edwards, H; Saez, A; Petersen, E; Evengard, B; Chiodini, P

2014-01-01

To determine the routine diagnostic methods used and compare the performance in detection of oocysts of Cryptosporidium species and cysts of Giardia intestinalis in faecal samples by European specialist parasitology laboratories and European clinical laboratories. Two sets of seven formalin-preserved faecal samples, one containing cysts of Giardia intestinalis and the other, containing oocysts of Cryptosporidium, were sent to 18 laboratories. Participants were asked to examine the specimens using their routine protocol for detecting these parasites and state the method(s) used. Eighteen laboratories answered the questionnaire. For detection of Giardia, 16 of them used sedimentation/concentration followed by light microscopy. Using this technique the lower limit of detection of Giardia was 17.2 cysts/mL of faeces in the best performing laboratories. Only three of 16 laboratories used fluorescent-conjugated antibody-based microscopy. For detection of Cryptosporidium acid-fast staining was used by 14 of the 17 laboratories that examined the samples. With this technique the lower limit of detection was 976 oocysts/mL of faeces. Fluorescent-conjugated antibody-based microscopy was used by only five of the 17 laboratories. There was variation in the lower limit of detection of cysts of Giardia and oocysts of Cryptosporidium between laboratories using the same basic microscopic methods. Fluorescent-conjugated antibody-based microscopy was not superior to light microscopy under the conditions of this study. There is a need for a larger-scale multi-site comparison of the methods used for the diagnosis of these parasites and the development of a Europe-wide laboratory protocol based upon its findings. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

Laboratory Study of Wave Generation Near Dipolarization Fronts

NASA Astrophysics Data System (ADS)

Tejero, E. M.; Enloe, C. L.; Amatucci, B.; Crabtree, C. E.; Ganguli, G.; Malaspina, D.

2017-12-01

Experiments conducted in the Space Physics Simulation Chamber at the Naval Research Laboratory (NRL) create plasma equilibria that replicate those found in dipolarization fronts. These experiments were designed to study the dynamics of boundary layers, such as dipolarization fronts, and it was found that there are instabilities generated by highly inhomogeneous plasma flows. It has previously been shown that these highly inhomogeneous flows can generate waves in the lower hybrid frequency range. Analysis of satellite observations indicate that the sheared flows are a plausible explanation for the observed lower hybrid waves at dipolarization fronts since they can generate longer wavelengths compared to the electron gyroradius, which is consistent with observations. Recent experiments at NRL have demonstrated that these flows can also generate electromagnetic waves in the whistler band. These waves are large amplitude, bursty waves that exhibit frequency chirps similar to whistler mode chorus. Recent results from these experiments and comparisons to in situ observations will be presented. * Work supported by the Naval Research Laboratory Base Program and NASA Grant No. NNH17AE70I.

An Experimental Study of Atmospheric Homogeneous Nucleation: Cluster Growth and Gas-Particle Reactions of H2SO4

NASA Technical Reports Server (NTRS)

Eisele, F. L.

1996-01-01

The work proposed on this project included both field and laboratory studies. The laboratory studies were to consist of measurements of H2SO4 uptake and evaporation from aerosols of varying chemical composition, while the field component would include measurements of H2SO4 and other compounds which would be conducted as part of a large field campaign. By chance, the opportunity to conduct such an H2SO4/aerosol/ultrafine particle study in conjunction with an OH intercomparison/photochemistry study became available very early in this project (September 1993). This study was conducted at Caribou, Colorado in conjunction with several other groups from NCAR, NOAA and a number of universities. Our group measured OH, H2SO4, SO2, and H20, while Dr. McMurfy's group measured ultrafine particles, and total particle number and size distribution. In addition measurements of HO2/RO2, O3, NO, NO2, NO(y) CO, hydrocarbons, CH2O, and other chemical compounds and meteorological parameters were performed by the other participants and a new laser oblation/mass spectrometry technique was also employed by the NOAA Aeronomy Laboratory to study aerosol composition. The study of aerosol production and growth in conjunction with photochemical measurements is highly advantageous because particle growth precursors such as H2SO4.or MSA are formed by OH initiated sulfur oxidation. The large number of hydrocarbon measurements included in this study were also important in understanding particle growth.

Ozone Response to Aircraft Emissions: Sensitivity Studies with Two-dimensional Models

NASA Technical Reports Server (NTRS)

Ko, Malcolm K. W.; Weisenstein, Debra; Jackman, Charles H.; Douglass, Anne R.; Bureske, K.; Weubbles, Donald J.; Kinnison, Douglas E.; Brasseur, G.; Pyle, J.; Jones, Anna

1992-01-01

Our first intercomparison/assessment of the effects of a proposed high-speed civil transport (HSCT) fleet on the stratosphere is presented. These model calculations should be considered more as sensitivity studies, primarily designed to serve the following purposes: (1) to allow for intercomparison of model predictions; (2) to focus on the range of fleet operations and engine specifications giving minimal environmental impact; and (3) to provide the basis for future assessment studies. The basic scenarios were chosen to be as realistic as possible, using the information available on anticipated developments in technology. They are not to be interpreted as a commitment or goal for environmental acceptability.

Light extinction by Secondary Organic Aerosol: an intercomparison of three broadband cavity spectrometers

NASA Astrophysics Data System (ADS)

Varma, R. M.; Ball, S. M.; Brauers, T.; Dorn, H.-P.; Heitmann, U.; Jones, R. L.; Platt, U.; Pöhler, D.; Ruth, A. A.; Shillings, A. J. L.; Thieser, J.; Wahner, A.; Venables, D. S.

2013-07-01

Broadband optical cavity spectrometers are maturing as a technology for trace gas detection, but only recently have they been used to retrieve the extinction coefficient of aerosols. Sensitive broadband extinction measurements allow explicit separation of gas and particle phase spectral contributions, as well as continuous spectral measurements of aerosol extinction in favourable cases. In this work, we report an intercomparison study of the aerosol extinction coefficients measured by three such instruments: a broadband cavity ring-down spectrometer (BBCRDS), a cavity-enhanced differential optical absorption spectrometer (CE-DOAS), and an incoherent broadband cavity-enhanced absorption spectrometer (IBBCEAS). Experiments were carried out in the SAPHIR atmospheric simulation chamber as part of the NO3Comp campaign to compare the measurement capabilities of NO3 and N2O5 instrumentation. Aerosol extinction coefficients between 655 and 690 nm are reported for secondary organic aerosols (SOA) formed by the NO3 oxidation of β-pinene under dry and humid conditions. Despite different measurement approaches and spectral analysis procedures, the three instruments retrieved aerosol extinction coefficients that were in close agreement. The refractive index of SOA formed from the β-pinene + NO3 reaction was 1.61, and was not measurably affected by the chamber humidity or by aging of the aerosol over several hours. This refractive index is significantly larger than SOA refractive indices observed in other studies of OH and ozone-initiated terpene oxidations, and may be caused by the large proportion of organic nitrates in the particle phase. In an experiment involving ammonium sulphate particles the aerosol extinction coefficients as measured by IBBCEAS were found to be in reasonable agreement with those calculated using Mie theory. The results of the study demonstrate the potential of broadband cavity spectrometers for determining the optical properties of aerosols.

Light extinction by secondary organic aerosol: an intercomparison of three broadband cavity spectrometers

NASA Astrophysics Data System (ADS)

Varma, R. M.; Ball, S. M.; Brauers, T.; Dorn, H.-P.; Heitmann, U.; Jones, R. L.; Platt, U.; Pöhler, D.; Ruth, A. A.; Shillings, A. J. L.; Thieser, J.; Wahner, A.; Venables, D. S.

2013-11-01

Broadband optical cavity spectrometers are maturing as a technology for trace-gas detection, but only recently have they been used to retrieve the extinction coefficient of aerosols. Sensitive broadband extinction measurements allow explicit separation of gas and particle phase spectral contributions, as well as continuous spectral measurements of aerosol extinction in favourable cases. In this work, we report an intercomparison study of the aerosol extinction coefficients measured by three such instruments: a broadband cavity ring-down spectrometer (BBCRDS), a cavity-enhanced differential optical absorption spectrometer (CE-DOAS), and an incoherent broadband cavity-enhanced absorption spectrometer (IBBCEAS). Experiments were carried out in the SAPHIR atmospheric simulation chamber as part of the NO3Comp campaign to compare the measurement capabilities of NO3 and N2O5 instrumentation. Aerosol extinction coefficients between 655 and 690 nm are reported for secondary organic aerosols (SOA) formed by the NO3 oxidation of β-pinene under dry and humid conditions. Despite different measurement approaches and spectral analysis procedures, the three instruments retrieved aerosol extinction coefficients that were in close agreement. The refractive index of SOA formed from the β-pinene + NO3 reaction was 1.61, and was not measurably affected by the chamber humidity or by aging of the aerosol over several hours. This refractive index is significantly larger than SOA refractive indices observed in other studies of OH and ozone-initiated terpene oxidations, and may be caused by the large proportion of organic nitrates in the particle phase. In an experiment involving ammonium sulfate particles, the aerosol extinction coefficients as measured by IBBCEAS were found to be in reasonable agreement with those calculated using the Mie theory. The results of the study demonstrate the potential of broadband cavity spectrometers for determining the optical properties of aerosols.

Laboratory study of spectral waves over a muddy bottom

NASA Astrophysics Data System (ADS)

Maxeiner, E.; Dalrymple, R. A.

2010-12-01

The attenuation of water waves propagating over a muddy ocean floor has been studied extensively both analytically and experimentally over the past 30 years. Possible mechanisms for this include surface wave interactions with the bottom, surface wave interactions with waves formed at the water/mud interface (lutocline) and shear instability at the water/mud interface. Typically these studies have focused on monochromatic waves. Observations of wave attenuation in the field, however, are subject to a spectrum of wave frequencies and sizes. A few field studies (Sheremet and Stone, 2003; Elgar and Raubenheimer, 2008) have explored the possible effects that a wide spectrum of wave frequencies may have on wave damping mechanisms. In this study, the wave attenuation exhibited by a sea spectrum over a muddy bottom is studied experimentally in a laboratory for the first time. Using an 18 m-long wave tank at the Coastal Engineering Laboratory at Johns Hopkins University, a piston-style wave maker is used to create both monochromatic and spectral waves. A 10 m-long section of the tank floor incorporates a recessed layer of kaolinite clay which subsequently mixes with the overlying water in the presence of waves. Testing consists of three phases. First, a series of monochromatic wave trains are produced over a range of wave frequencies and in a range of water depths to assess the damping behavior with respect to a variety of parameters such as wave frequency, wave height and water depth. Damping is assessed by comparing wave height at various longitudinal locations in the tank. Second, “wave beats” are created by superimposing waves of two frequencies to create a longer envelope. Third, the wave maker is used to generate a representative random sea condition, based on the Pierson-Moskowitz sea spectrum. For this type of testing, damping is assessed by measuring wave energy flux over a period of time at various longitudinal locations in the tank. Spectral analysis is also

Intercomparisons of high-resolution solar blind Raman lidar atmospheric profiles of water vapor with radiosondes and kytoon

NASA Technical Reports Server (NTRS)

Petri, K.; Salik, A.; Cooney, J.

1986-01-01

A report is given of measurements of atmospheric profiles of water vapor in the boundary layer by use of solar blind Raman lidar. These measurement episodes, occuring twice a day over a two week period, were accompanied by a dense net of supporting measurements. The support included two radiosonde launches per measurement episodes as well as a kytoon support measurement of water vapor using a wet bulb-dry bulb instrument. The kytoon strategy included ten minute stops at strategic altitudes. Additional kytoon measurements included ozone profiles and nephelometric extinction profiles in the visible. Typically, six or seven 1000 shot lidar profile averages were collected during a measurement episode. Overall performance comparisons are provided and intercomparisons between auxiliary measurement devices are presented. Data on the accuracy of the lidar water vapor profiles are presented.

Variances and uncertainties of the sample laboratory-to-laboratory variance (S(L)2) and standard deviation (S(L)) associated with an interlaboratory study.

PubMed

McClure, Foster D; Lee, Jung K

2012-01-01

The validation process for an analytical method usually employs an interlaboratory study conducted as a balanced completely randomized model involving a specified number of randomly chosen laboratories, each analyzing a specified number of randomly allocated replicates. For such studies, formulas to obtain approximate unbiased estimates of the variance and uncertainty of the sample laboratory-to-laboratory (lab-to-lab) STD (S(L)) have been developed primarily to account for the uncertainty of S(L) when there is a need to develop an uncertainty budget that includes the uncertainty of S(L). For the sake of completeness on this topic, formulas to estimate the variance and uncertainty of the sample lab-to-lab variance (S(L)2) were also developed. In some cases, it was necessary to derive the formulas based on an approximate distribution for S(L)2.

Intercomparison of Multiscale Modeling Approaches in Simulating Subsurface Flow and Transport

NASA Astrophysics Data System (ADS)

Yang, X.; Mehmani, Y.; Barajas-Solano, D. A.; Song, H. S.; Balhoff, M.; Tartakovsky, A. M.; Scheibe, T. D.

2016-12-01

Hybrid multiscale simulations that couple models across scales are critical to advance predictions of the larger system behavior using understanding of fundamental processes. In the current study, three hybrid multiscale methods are intercompared: multiscale loose-coupling method, multiscale finite volume (MsFV) method and multiscale mortar method. The loose-coupling method enables a parallel workflow structure based on the Swift scripting environment that manages the complex process of executing coupled micro- and macro-scale models without being intrusive to the at-scale simulators. The MsFV method applies microscale and macroscale models over overlapping subdomains of the modeling domain and enforces continuity of concentration and transport fluxes between models via restriction and prolongation operators. The mortar method is a non-overlapping domain decomposition approach capable of coupling all permutations of pore- and continuum-scale models with each other. In doing so, Lagrange multipliers are used at interfaces shared between the subdomains so as to establish continuity of species/fluid mass flux. Subdomain computations can be performed either concurrently or non-concurrently depending on the algorithm used. All the above methods have been proven to be accurate and efficient in studying flow and transport in porous media. However, there has not been any field-scale applications and benchmarking among various hybrid multiscale approaches. To address this challenge, we apply all three hybrid multiscale methods to simulate water flow and transport in a conceptualized 2D modeling domain of the hyporheic zone, where strong interactions between groundwater and surface water exist across multiple scales. In all three multiscale methods, fine-scale simulations are applied to a thin layer of riverbed alluvial sediments while the macroscopic simulations are used for the larger subsurface aquifer domain. Different numerical coupling methods are then applied between

The Detection and Attribution Model Intercomparison Project (DAMIP v1.0)contribution to CMIP6

DOE PAGES

Gillett, Nathan P.; Shiogama, Hideo; Funke, Bernd; ...

2016-10-18

Detection and attribution (D&A) simulations were important components of CMIP5 and underpinned the climate change detection and attribution assessments of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The primary goals of the Detection and Attribution Model Intercomparison Project (DAMIP) are to facilitate improved estimation of the contributions of anthropogenic and natural forcing changes to observed global warming as well as to observed global and regional changes in other climate variables; to contribute to the estimation of how historical emissions have altered and are altering contemporary climate risk; and to facilitate improved observationally constrained projections of futuremore » climate change. D&A studies typically require unforced control simulations and historical simulations including all major anthropogenic and natural forcings. Such simulations will be carried out as part of the DECK and the CMIP6 historical simulation. In addition D&A studies require simulations covering the historical period driven by individual forcings or subsets of forcings only: such simulations are proposed here. Key novel features of the experimental design presented here include firstly new historical simulations with aerosols-only, stratospheric-ozone-only, CO2-only, solar-only, and volcanic-only forcing, facilitating an improved estimation of the climate response to individual forcing, secondly future single forcing experiments, allowing observationally constrained projections of future climate change, and thirdly an experimental design which allows models with and without coupled atmospheric chemistry to be compared on an equal footing.« less

The Detection and Attribution Model Intercomparison Project (DAMIP v1.0) contribution to CMIP6

NASA Astrophysics Data System (ADS)

Gillett, Nathan P.; Shiogama, Hideo; Funke, Bernd; Hegerl, Gabriele; Knutti, Reto; Matthes, Katja; Santer, Benjamin D.; Stone, Daithi; Tebaldi, Claudia

2016-10-01

Detection and attribution (D&A) simulations were important components of CMIP5 and underpinned the climate change detection and attribution assessments of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. The primary goals of the Detection and Attribution Model Intercomparison Project (DAMIP) are to facilitate improved estimation of the contributions of anthropogenic and natural forcing changes to observed global warming as well as to observed global and regional changes in other climate variables; to contribute to the estimation of how historical emissions have altered and are altering contemporary climate risk; and to facilitate improved observationally constrained projections of future climate change. D&A studies typically require unforced control simulations and historical simulations including all major anthropogenic and natural forcings. Such simulations will be carried out as part of the DECK and the CMIP6 historical simulation. In addition D&A studies require simulations covering the historical period driven by individual forcings or subsets of forcings only: such simulations are proposed here. Key novel features of the experimental design presented here include firstly new historical simulations with aerosols-only, stratospheric-ozone-only, CO2-only, solar-only, and volcanic-only forcing, facilitating an improved estimation of the climate response to individual forcing, secondly future single forcing experiments, allowing observationally constrained projections of future climate change, and thirdly an experimental design which allows models with and without coupled atmospheric chemistry to be compared on an equal footing.

Performance study of various Condensation Particle Counters (CPCs): development of a methodology based on steady-state airborne DEHS particles and application to a series of handheld and stationary CPCs

NASA Astrophysics Data System (ADS)

Bau, Sébastien; Toussaint, André; Payet, Raphaël; Witschger, Olivier

2017-06-01

Strategies for measuring occupational exposure to aerosols composed of nanoparticles and/or ultrafine particles highlight the use of techniques for determining airborne-particle number concentration as well as number size distribution. The objective of the present work was to set up a system for conducting laboratory verification campaigns of condensation particle counters (CPCs). Providing intercomparison data as well as calibrating and checking CPCs are among the key elements in ensuring reliable laboratory or field measurement campaigns. For this purpose, the reproducible aerosol source “Calibration Tool”, initially developed by the Fraunhofer ITEM, was acquired by the Laboratory of Aerosol Metrology at INRS. As a first part of this study, a detailed characterization of the Calibration Tool developed at the laboratory is the subject of the parametric study presented here. The complete installation is named the “DCC” for “Device for Counter Check”. Used in combination with a reference counter, the DCC can now be used for routine laboratory measurements. Unlike that used for primary calibration of a CPC, the proposed protocol allows a wide range of number concentrations and particle sizes to be investigated and reproduced. The second part of this work involves comparison of the number concentrations measured by several models of CPC in parallel at the exit of a flow splitter, with respect to a reference.

21 CFR 58.130 - Conduct of a nonclinical laboratory study.

Code of Federal Regulations, 2010 CFR

2010-04-01

... specimen in a manner that precludes error in the recording and storage of data. (d) Records of gross... that specimen histopathologically. (e) All data generated during the conduct of a nonclinical laboratory study, except those that are generated by automated data collection systems, shall be recorded...

21 CFR 58.130 - Conduct of a nonclinical laboratory study.

Code of Federal Regulations, 2013 CFR

2013-04-01

... specimen in a manner that precludes error in the recording and storage of data. (d) Records of gross... that specimen histopathologically. (e) All data generated during the conduct of a nonclinical laboratory study, except those that are generated by automated data collection systems, shall be recorded...

21 CFR 58.130 - Conduct of a nonclinical laboratory study.

Code of Federal Regulations, 2011 CFR

2011-04-01

... specimen in a manner that precludes error in the recording and storage of data. (d) Records of gross... that specimen histopathologically. (e) All data generated during the conduct of a nonclinical laboratory study, except those that are generated by automated data collection systems, shall be recorded...

SEWER SEDIMENT GATE AND VACUUM FLUSHING TANKS: LABORATORY FLUME STUDIES

EPA Science Inventory

The objective of this study was to test the performance of a traditional gate-flushing device and a newly designed vacuum-flushing device in removing sediments from combined sewers and CSO storage tanks. A laboratory hydraulic flune was used to simulate a reach of sewer or storag...

Assessing doses to terrestrial wildlife at a radioactive waste disposal site: inter-comparison of modelling approaches.

PubMed

Johansen, M P; Barnett, C L; Beresford, N A; Brown, J E; Černe, M; Howard, B J; Kamboj, S; Keum, D-K; Smodiš, B; Twining, J R; Vandenhove, H; Vives i Batlle, J; Wood, M D; Yu, C

2012-06-15

Radiological doses to terrestrial wildlife were examined in this model inter-comparison study that emphasised factors causing variability in dose estimation. The study participants used varying modelling approaches and information sources to estimate dose rates and tissue concentrations for a range of biota types exposed to soil contamination at a shallow radionuclide waste burial site in Australia. Results indicated that the dominant factor causing variation in dose rate estimates (up to three orders of magnitude on mean total dose rates) was the soil-to-organism transfer of radionuclides that included variation in transfer parameter values as well as transfer calculation methods. Additional variation was associated with other modelling factors including: how participants conceptualised and modelled the exposure configurations (two orders of magnitude); which progeny to include with the parent radionuclide (typically less than one order of magnitude); and dose calculation parameters, including radiation weighting factors and dose conversion coefficients (typically less than one order of magnitude). Probabilistic approaches to model parameterisation were used to encompass and describe variable model parameters and outcomes. The study confirms the need for continued evaluation of the underlying mechanisms governing soil-to-organism transfer of radionuclides to improve estimation of dose rates to terrestrial wildlife. The exposure pathways and configurations available in most current codes are limited when considering instances where organisms access subsurface contamination through rooting, burrowing, or using different localised waste areas as part of their habitual routines. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Infrared Spectral Radiance Intercomparisons With Satellite and Aircraft Sensors

NASA Technical Reports Server (NTRS)

Larar, Allen M.; Zhou, Daniel K.; Liu, Xu; Smith, William L.

2014-01-01

Measurement system validation is critical for advanced satellite sounders to reach their full potential of improving observations of the Earth's atmosphere, clouds, and surface for enabling enhancements in weather prediction, climate monitoring capability, and environmental change detection. Experimental field campaigns, focusing on satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft, are an essential part of the validation task. Airborne FTS systems can enable an independent, SI-traceable measurement system validation by directly measuring the same level-1 parameters spatially and temporally coincident with the satellite sensor of interest. Continuation of aircraft under-flights for multiple satellites during multiple field campaigns enables long-term monitoring of system performance and inter-satellite cross-validation. The NASA / NPOESS Airborne Sounder Testbed - Interferometer (NAST-I) has been a significant contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This presentation gives an overview of benefits achieved using airborne sensors such as NAST-I utilizing examples from recent field campaigns. The methodology implemented is not only beneficial to new sensors such as the Cross-track Infrared Sounder (CrIS) flying aboard the Suomi NPP and future JPSS satellites but also of significant benefit to sensors of longer flight heritage such as the Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) on the AQUA and METOP-A platforms, respectively, to ensure data quality continuity important for climate and other applications. Infrared spectral radiance inter-comparisons are discussed with a particular focus on usage of NAST-I data for enabling inter-platform cross-validation.

Introduction The Role of the Agricultural Model Intercomparison and Improvement Project

NASA Technical Reports Server (NTRS)

Rosenzweig, Cynthia; Hillel, Daniel

2015-01-01

Climate impacts on agriculture are of increasing concern in both the scientific and policy communities because of the need to ensure food security for a growing population. A special challenge is posed by the changes in the frequency and intensity of heat-waves, droughts, and episodic rainstorms already underway in many parts of the world. Changes in production are directly linked to such variations in temperature and precipitation during the growing season, and often to offseason changes in weather affecting soil-water storage and availability to crops. This is not an isolated problem but one of both global and regional importance, because of impacts on the livelihoods of smallholder farmers as well as consequences for the world food trade system. This two-part set the Agricultural Model Intercomparison and Improvement Project (AgMIP): Integrated Crop and Economic Assessments is the first to be entirely devoted to AgMIP (www.agmip.org). AgMIP is a major international research program focused on climate change and agriculture. The goal of the two parts is to advance the field by providing detailed information on new simulation techniques and assessments being conducted by this program. It presents information about new methods of global and regional integrated assessment, results from agricultural regions, and adaptation strategies for maintaining food security under changing climate conditions.

Safety in laboratories: Indian scenario.

PubMed

Mustafa, Ajaz; Farooq, A Jan; Qadri, Gj; S A, Tabish

2008-07-01

Health and safety in clinical laboratories is becoming an increasingly important subject as a result of emergence of highly infectious diseases such as Hepatitis and HIV. A cross sectional study was carried out to study the safety measures being adopted in clinical laboratories of India. Heads of laboratories of teaching hospitals of India were subjected to a standardized, pretested questionnaire. Response rate was 44.8%. only 60% of laboratories had person in-charge of safety in laboratory. Seventy three percent of laboratories had safety education program regarding hazards. In 91% of laboratories staff is using protective clothing while working in laboratories. Hazardous material regulations are followed in 78% of laboratories. Regular health check ups are carried among laboratory staff in 43.4% of laboratories.Safety manual is available in 56.5% of laboratories. 73.9% of laboratories are equipped with fire extinguishers. Fume cupboards are provided in 34.7% of laboratories and they are regularly checked in 87.5% of these laboratories. In 78.26% of laboratories suitable measures are taken to minimize formation of aerosols.In 95.6% of laboratories waste is disposed off as per bio-medical waste management handling rules. Laboratory of one private medical college was accredited with NABL and safety parameters were better in that laboratory. Installing safety engineered devices apparently contributes to significant decrease in injuries in laboratories; laboratory safety has to be a part of overall quality assurance programme in hospitals. Accreditation has to be made necessary for all laboratories.

A cross-laboratory preclinical study on the effectiveness of interleukin-1 receptor antagonist in stroke

PubMed Central

Maysami, Samaneh; Wong, Raymond; Pradillo, Jesus M; Denes, Adam; Dhungana, Hiramani; Malm, Tarja; Koistinaho, Jari; Orset, Cyrille; Rahman, Mahbubur; Rubio, Marina; Schwaninger, Markus; Vivien, Denis; Bath, Philip M; Rothwell, Nancy J

2015-01-01

Stroke represents a global challenge and is a leading cause of permanent disability worldwide. Despite much effort, translation of research findings to clinical benefit has not yet been successful. Failure of neuroprotection trials is considered, in part, due to the low quality of preclinical studies, low level of reproducibility across different laboratories and that stroke co-morbidities have not been fully considered in experimental models. More rigorous testing of new drug candidates in different experimental models of stroke and initiation of preclinical cross-laboratory studies have been suggested as ways to improve translation. However, to our knowledge, no drugs currently in clinical stroke trials have been investigated in preclinical cross-laboratory studies. The cytokine interleukin 1 is a key mediator of neuronal injury, and the naturally occurring interleukin 1 receptor antagonist has been reported as beneficial in experimental studies of stroke. In the present paper, we report on a preclinical cross-laboratory stroke trial designed to investigate the efficacy of interleukin 1 receptor antagonist in different research laboratories across Europe. Our results strongly support the therapeutic potential of interleukin 1 receptor antagonist in experimental stroke and provide further evidence that interleukin 1 receptor antagonist should be evaluated in more extensive clinical stroke trials. PMID:26661169

Laboratory performance in the Sediment Laboratory Quality-Assurance Project, 1996-98

USGS Publications Warehouse

Gordon, John D.; Newland, Carla A.; Gagliardi, Shane T.

2000-01-01

Analytical results from all sediment quality-control samples are compiled and statistically summarized by the USGS, Branch of Quality Systems, both on an intra- and interlaboratory basis. When evaluating these data, the reader needs to keep in mind that every measurement has an error component associated with it. It is premature to use the data from the first five SLQA studies to judge any of the laboratories as performing in an unacceptable manner. There were, however, some notable differences in the results for the 12 laboratories that participated in the five SLQA studies. For example, the overall median percent difference for suspended-sediment concentration on an individual laboratory basis ranged from –18.04 to –0.33 percent. Five of the 12 laboratories had an overall median percent difference for suspended-sediment concentration of –2.02 to –0.33 percent. There was less variability in the median difference for the measured fine-size material mass. The overall median percent difference for fine-size material mass ranged from –10.11 to –4.27 percent. Except for one laboratory, the median difference for fine-size material mass was within a fairly narrow range of –6.76 to –4.27 percent. The median percent difference for sand-size material mass differed among laboratories more than any other physical sediment property measured in the study. The overall median percent difference for the sand-size material mass ranged from –1.49 percent to 26.39 percent. Five of the nine laboratories that do sand/fine separations had overall median percent differences that ranged from –1.49 to 2.98 percent for sand-size material mass. Careful review of the data reveals that certain laboratories consistently produced data within statistical control limits for some or all of the physical sediment properties measured in this study, whereas other laboratories occasionally produced data that exceeded the control limits.

Atmospheric River Tracking Method Intercomparison Project (ARTMIP): Science Goals and Preliminary Analysis

NASA Astrophysics Data System (ADS)

Shields, C. A.; Rutz, J. J.; Wehner, M. F.; Ralph, F. M.; Leung, L. R.

2017-12-01

The Atmospheric River Tracking Method Intercomparison Project (ARTMIP) is a community effort whose purpose is to quantify uncertainties in atmospheric river (AR) research solely due to different identification and tracking techniques. Atmospheric rivers transport significant amounts of moisture in long, narrow filamentary bands, typically travelling from the subtropics to the mid-latitudes. They are an important source of regional precipitation impacting local hydroclimate, and in extreme cases, cause severe flooding and infrastructure damage in local communities. Our understanding of ARs, from forecast skill to future climate projections, all hinge on how we define ARs. By comparing a diverse set of detection algorithms, the uncertainty in our definition of ARs, (including statistics and climatology), and the implications of those uncertainties, can be analyzed and quantified. ARTMIP is divided into two broad phases that aim to answer science questions impacted by choice of detection algorithm. How robust are AR metrics such as climatology, storm duration, and relationship to extreme precipitation? How are the AR metrics in future climate projections impacted by choice of algorithm? Some algorithms rely on threshold values for water vapor. In a warmer world, the background state, by definition, is moister due to the Clausius-Clapeyron relationship, and could potentially skew results. Can uncertainty bounds be accurately placed on each metric? Tier 1 participants will apply their algorithms to a high resolution common dataset (MERRA2) and provide the greater group AR metrics (frequency, location, duration, etc). Tier 2 research will encompass sensitivity studies regarding resolution, reanalysis choice, and future climate change scenarios. ARTMIP is currently in the Tier 1 Phase and will begin Tier 2 in 2018. Preliminary metrics and analysis from Tier 1 will be presented.

Biofilm resilience to desiccation in groundwater aquifers: a laboratory and field study.

PubMed

Weaver, L; Webber, J B; Hickson, A C; Abraham, P M; Close, M E

2015-05-01

Groundwater is used as a precious resource for drinking water worldwide. Increasing anthropogenic activity is putting increasing pressure on groundwater resources. One impact of increased groundwater abstraction coupled with increasing dry weather events is the lowering of groundwater levels within aquifers. Biofilms within groundwater aquifers offer protection to the groundwater by removing contaminants entering the aquifer systems from land use activities. The study presented investigated the impact of desiccation events on the biofilms present in groundwater aquifers using field and laboratory experiments. In both field and laboratory experiments a reduction in enzyme activity (glucosidase, esterase and phosphatase) was seen during desiccation compared to wet controls. However, comparing all the data together no significant differences were seen between either wet or desiccated samples or between the start and end of the experiments. In both field and laboratory experiments enzyme activity recovered to start levels after return to wet conditions. The study shows that biofilms within groundwater systems are resilient and can withstand periods of desiccation (4 months). Copyright © 2014 Elsevier B.V. All rights reserved.

A STUDY OF SMALL GROUP DYNAMICS AND PRODUCTIVITY IN THE BSCS LABORATORY BLOCK PROGRAM.

ERIC Educational Resources Information Center

HURD, PAUL DEHART; ROWE, MARY BUDD

THE RELATIONSHIP BETWEEN SMALL GROUP COMPATIBILITY AND ACHIEVEMENT IN THE BIOLOGICAL SCIENCE CURRICULUM STUDY LABORATORY BLOCK PROGRAM WAS TESTED. STUDENTS IN 14 CLASSES FROM FOUR HIGH SCHOOLS WERE ASSIGNED TO FOUR-MEMBER LABORATORY GROUPS CLASSIFIED AS COMPATIBLE OR INCOMPATIBLE. GROUP CLASSIFICATION WAS VALIDATED BY OBSERVERS WHO WERE NOT AWARE…

[Laboratory and clinical study of intravenous miconazole].

PubMed

Sawae, Y; Okada, K; Kumagai, Y

1987-02-01

Laboratory and clinical study was carried out on miconazole (MCZ), a new synthetic imidazole. The antifungal activity of MCZ was studied and expressed as MICs for clinical isolates. The drug proved to have the highest activity against Cryptococcus neoformans, with MICs of no more than 0.16 micrograms/ml for all isolates of this species. MICs of Torulopsis glabrata were 0.08-5 micrograms/ml for all isolates and those of Candida albicans and Candida tropicalis were 5-20 micrograms/ml for more than 90% of the isolates. Most of other strains were less than 10 micrograms/ml. When 3 healthy adult men were administered each with 200 mg of MCZ by intravenous drip infusion for 1.25 hours, the mean serum MCZ concentration was 1.39 micrograms/ml at the end of the infusion, then decreased rapidly to 0.49 microgram/ml in following 30 minutes, and then decreased gradually to 0.17 microgram/ml 6 hours later. The mean cumulative urinary excretion rate of the drug was as low as 3.0% at this stage. A total of 25 patients with ages of 30-78 years, comprising 17 men and 8 women, were treated with 200-1,800 mg of MCZ daily for 3-93 days. The clinical effectiveness was ascertained in 19 cases among the patients; 9 cases with candidiasis, 3 with cryptococcosis and 7 with aspergillosis. Clinical responses were excellent in 2, good in 9 and poor in 8 cases, and its efficacy rates was 58%. The efficacy rate of the combination therapy with other antifungal agents was 60% in comparison with 57% of MCZ alone. Adverse reactions to the drug such as nausea, vomiting and anorexia were observed in 3 cases (12%). Abnormal changes in laboratory parameters were also observed: 3 patients with elevations of GOT and GPT, and another with eosinophilia.

[The external evaluation of study quality: the role in maintaining the reliability of laboratory information].

PubMed

Men'shikov, V V

2013-08-01

The external evaluation of quality of clinical laboratory examinations was gradually introduced in USSR medical laboratories since 1970s. In Russia, in the middle of 1990 a unified all-national system of external evaluation quality was organized known as the Federal center of external evaluation of quality at the basis of laboratory of the state research center of preventive medicine. The main positions of policy in this area were neatly formulated in the guidance documents of ministry of Health. Nowadays, the center of external evaluation of quality proposes 100 and more types of control studies and permanently extends their specter starting from interests of different disciplines of clinical medicine. The consistent participation of laboratories in the cycles of external evaluation of quality intrinsically promotes improvement of indicators of properness and precision of analysis results and increases reliability of laboratory information. However, a significant percentage of laboratories does not participate at all in external evaluation of quality or takes part in control process irregularly and in limited number of tests. The managers of a number of medical organizations disregard the application of the proposed possibilities to increase reliability of laboratory information and limit financing of studies in the field of quality control. The article proposes to adopt the national standard on the basis of ISO 17043 "Evaluation of compliance. The common requirements of professional competence testing".

Intercomparison of Lab-Based Soil Water Extraction Methods for Stable Water Isotope Analysis

NASA Astrophysics Data System (ADS)

Pratt, D.; Orlowski, N.; McDonnell, J.

2016-12-01

The effect of pore water extraction technique on resultant isotopic signature is poorly understood. Here we present results of an intercomparison of five common lab-based soil water extraction techniques: high pressure mechanical squeezing, centrifugation, direct vapor equilibration, microwave extraction, and cryogenic extraction. We applied five extraction methods to two physicochemically different standard soil types (silty sand and clayey loam) that were oven-dried and rewetted with water of known isotopic composition at three different gravimetric water contents (8, 20, and 30%). We tested the null hypothisis that all extraction techniques would provide the same isotopic result independent from soil type and water content. Our results showed that the extraction technique had a significant effect on the soil water isotopic composition. Each method exhibited deviations from spiked reference water, with soil type and water content showing a secondary effect. Cryogenic extraction showed the largest deviations from the reference water, whereas mechanical squeezing and centrifugation provided the closest match to the reference water for both soil types. We also compared results for each extraction technique that produced liquid water on both an OA-ICOS and IRMS; differences between them were negligible.

Intercomparison of three microwave/infrared high resolution line-by-line radiative transfer codes

NASA Astrophysics Data System (ADS)

Schreier, Franz; Milz, Mathias; Buehler, Stefan A.; von Clarmann, Thomas

2018-05-01

An intercomparison of three line-by-line (lbl) codes developed independently for atmospheric radiative transfer and remote sensing - ARTS, GARLIC, and KOPRA - has been performed for a thermal infrared nadir sounding application assuming a HIRS-like (High resolution Infrared Radiation Sounder) setup. Radiances for the 19 HIRS infrared channels and a set of 42 atmospheric profiles from the "Garand dataset" have been computed. The mutual differences of the equivalent brightness temperatures are presented and possible causes of disagreement are discussed. In particular, the impact of path integration schemes and atmospheric layer discretization is assessed. When the continuum absorption contribution is ignored because of the different implementations, residuals are generally in the sub-Kelvin range and smaller than 0.1 K for some window channels (and all atmospheric models and lbl codes). None of the three codes turned out to be perfect for all channels and atmospheres. Remaining discrepancies are attributed to different lbl optimization techniques. Lbl codes seem to have reached a maturity in the implementation of radiative transfer that the choice of the underlying physical models (line shape models, continua etc) becomes increasingly relevant.

Representation of the Great Lakes in the Coupled Model Intercomparison Project Version 5

NASA Astrophysics Data System (ADS)

Briley, L.; Rood, R. B.

2017-12-01

The U.S. Great Lakes play a significant role in modifying regional temperatures and precipitation, and as the lakes change in response to a warming climate (i.e., warmer surface water temperatures, decreased ice cover, etc) lake-land-atmosphere dynamics are affected. Because the lakes modify regional weather and are a driver of regional climate change, understanding how they are represented in climate models is important to the reliability of model based information for the region. As part of the Great Lakes Integrated Sciences + Assessments (GLISA) Ensemble project, a major effort is underway to evaluate the Coupled Model Intercomparison Project version (CMIP) 5 global climate models for how well they physically represent the Great Lakes and lake-effects. The CMIP models were chosen because they are a primary source of information in many products developed for decision making (i.e., National Climate Assessment, downscaled future climate projections, etc.), yet there is very little description of how well they represent the lakes. This presentation will describe the results of our investigation of if and how the Great Lakes are represented in the CMIP5 models.

Introduction of the 2nd Phase of the Integrated Hydrologic Model Intercomparison Project

NASA Astrophysics Data System (ADS)

Kollet, Stefan; Maxwell, Reed; Dages, Cecile; Mouche, Emmanuel; Mugler, Claude; Paniconi, Claudio; Park, Young-Jin; Putti, Mario; Shen, Chaopeng; Stisen, Simon; Sudicky, Edward; Sulis, Mauro; Ji, Xinye

2015-04-01

The 2nd Phase of the Integrated Hydrologic Model Intercomparison Project commenced in June 2013 with a workshop at Bonn University funded by the German Science Foundation and US National Science Foundation. Three test cases were defined and compared that are available online at www.hpsc-terrsys.de including a tilted v-catchment case; a case called superslab based on multiple slab-heterogeneities in the hydraulic conductivity along a hillslope; and the Borden site case, based on a published field experiment. The goal of this phase is to further interrogate the coupling of surface-subsurface flow implemented in various integrated hydrologic models; and to understand and quantify the impact of differences in the conceptual and technical implementations on the simulation results, which may constitute an additional source of uncertainty. The focus has been broadened considerably including e.g. saturated and unsaturated subsurface storages, saturated surface area, ponded surface storage in addition to discharge, and pressure/saturation profiles and cross-sections. Here, first results are presented and discussed demonstrating the conceptual and technical challenges in implementing essentially the same governing equations describing highly non-linear moisture redistribution processes and surface-groundwater interactions.

Seven Principles of Instructional Content Design for a Remote Laboratory: A Case Study on ERRL

ERIC Educational Resources Information Center

Cagiltay, N. E.; Aydin, E.; Aydin, C. C.; Kara, A.; Alexandru, M.

2011-01-01

This paper discusses the results of a study of the requirements for developing a remote radio frequency (RF) laboratory for electrical engineering students. It investigates students' preferred usage of the technical content of a state-of-the-art RF laboratory. The results of this study are compared to previous findings, which dealt with other user…

Case study: improving efficiency in a large hospital laboratory.

PubMed

Bartel, Marilynn

2004-01-01

Saint Francis Health System (SFHS) consists of three hospitals and one clinic: Saint Francis Hospital (SFH); Broken Arrow Medical Center; Laureate Psychiatric Hospital; and Warren Clinic. SFHS has 670 physicians on staff and serves medical (oncology, orthopedic, neurology, and renal), surgical, cardiac, women and infant, pediatric, transplant, and trauma patients in Tulsa County, Oklahoma, which has a population of 660,000. SFH incorporates 706 staffed beds, including 126 pediatric beds and 119 critical care beds. Each year, the health system averages 38,000 admissions, 70,000 emergency department visits, 25,000 surgeries, and 3,500 births. Saint Francis Laboratory is located within the main hospital facility (SFH) and functions as a core lab for the health system. The lab also coordinates lab services with Saint Francis Heart Hospital, a physician-system joint venture. The Optimal Equipment Configuration (OEC) Project was designed by the Clinical Laboratory Services division of Premier, a group purchasing organization, with the goal of determining whether laboratories could improve efficiency and decrease unit cost by using a single-source vendor. Participants included seven business partners (Abbott, Bayer, Beckman/Coulter, Dade/Behring, J&J/ Ortho, Olympus, and Roche) and 21 laboratory sites (a small, mid-sized, and large site for each vendor). SFH laboratory staff embraced Premier's concept and viewed the OEC project as an opportunity to "energize" laboratory operations. SFH partnered with Abbott, their primary equipment vendor, for the project. Using resources and tools made available through the project, the laboratory was re-engineered to simplify workflow, increase productivity, and decrease costs by adding automation and changing to centralized specimen processing. Abbott and SFH shared a common vision for the project and enhanced their partnership through increased communication and problem solving. Abbott's area representatives provided for third

Field Research Studying Whales in an Undergraduate Animal Behavior Laboratory

ERIC Educational Resources Information Center

MacLaren, R. David; Schulte, Dianna; Kennedy, Jen

2012-01-01

This work describes a new field research laboratory in an undergraduate animal behavior course involving the study of whale behavior, ecology and conservation in partnership with a non-profit research organization--the Blue Ocean Society for Marine Conservation (BOS). The project involves two weeks of training and five weekend trips on whale watch…

Inter-comparison of network measurements of non-methane organic compounds with model simulations

NASA Astrophysics Data System (ADS)

Chen, Sheng-Po; Su, Yuan-Chang; Chiu, Ching-Jui; Lin, Ching-Ho; Chang, Julius S.; Chang, Chih-Chung; Wang, Jia-Lin

2015-12-01

Ambient levels of total non-methane organic carbons (NMOCs) at air quality stations (AQSs, called AQS NMOCs) are compared with the summed concentrations of 56 NMHCs obtained from the Photochemical Assessment Monitoring Stations (called total PAMS). For mutual validation of the two networks, the total PAMS were compared with the AQS NMOCs at four sites on the island of Taiwan for the period 2007-2012. The inter-comparison of total PAMS and AQS NMOCs has been discussed previously, which reported that the total PAMS accounted for approximately 30% of the AQS NMOCs on average (Chen et al., 2014b). In this study, both the observed total PAMS and AQS NMOCs were further compared with the emissions and model simulations for mutual validation. A three-dimensional Eulerian air quality model was used to simulate total PAMS and total VOCs, which were then inter-compared with the observed total PAMS and AQS NMOCs, respectively. We found closely agreeing results between the observed and simulated total PAMS, affirming that the treatment of meteorology and VOC emissions in the model was sufficiently robust. Further, although the modeled VOC data agreed with the AQS NMOC observations for the sites in urban settings, a significant discrepancy existed for the industrial sites, particularly at the concentration spikes. Such a discrepancy was presumably attributed to high emissions of OVOCs from industrial complexes compounded by the lower sensitivity of AQS measurements for OVOCs compared with hydrocarbons. Consequently, using AQS NMOCs to represent ambient VOC levels should be limited to environments where the amounts of OVOCs are relatively small relative to total VOCs.

Partnering at the National Laboratories: Catalysis as a Case Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

JACKSON,NANCY B.

1999-09-14

The role of the national laboratories, particularly the defense program laboratories, since the end of the cold war, has been a topic of continuing debate. The relationship of national laboratories to industry spurred debate which ranged from designating the labs as instrumental to maintaining U.S. economic competitiveness to concern over the perception of corporate welfare to questions regarding the industrial globalization and the possibility of U.S. taxpayer dollars supporting foreign entities. Less debated, but equally important, has been the national laboratories' potential competition with academia for federal research dollars and discussions detailing the role of each in the national researchmore » enterprise.« less

A SURVEY OF LABORATORY AND STATISTICAL ISSUES RELATED TO FARMWORKER EXPOSURE STUDIES

EPA Science Inventory

Developing internally valid, and perhaps generalizable, farmworker exposure studies is a complex process that involves many statistical and laboratory considerations. Statistics are an integral component of each study beginning with the design stage and continuing to the final da...

Feasibility study of a zero-gravity (orbital) atmospheric cloud physics experiments laboratory

NASA Technical Reports Server (NTRS)

Hollinden, A. B.; Eaton, L. R.

1972-01-01

A feasibility and concepts study for a zero-gravity (orbital) atmospheric cloud physics experiment laboratory is discussed. The primary objective was to define a set of cloud physics experiments which will benefit from the near zero-gravity environment of an orbiting spacecraft, identify merits of this environment relative to those of groundbased laboratory facilities, and identify conceptual approaches for the accomplishment of the experiments in an orbiting spacecraft. Solicitation, classification and review of cloud physics experiments for which the advantages of a near zero-gravity environment are evident are described. Identification of experiments for potential early flight opportunities is provided. Several significant accomplishments achieved during the course of this study are presented.

Cost-price estimation of clinical laboratory services based on activity-based costing: A case study from a developing country

PubMed Central

Mouseli, Ali; Barouni, Mohsen; Amiresmaili, Mohammadreza; Samiee, Siamak Mirab; Vali, Leila

2017-01-01

Background It is believed that laboratory tariffs in Iran don’t reflect the real costs. This might expose private laboratories at financial hardship. Activity Based Costing is widely used as a cost measurement instrument to more closely approximate the true cost of operations. Objective This study aimed to determine the real price of different clinical tests of a selected private clinical laboratory. Methods This study was a cross sectional study carried out in 2015. The study setting was the private laboratories in the city of Kerman, Iran. Of 629 tests in the tariff book of the laboratory (relative value), 188 tests were conducted in the laboratory that used Activity Based Costing (ABC) methodology to estimate cost-price. Analyzing and cost-price estimating of laboratory services were performed by MY ABCM software Version 5.0. Results In 2015, the total costs were $641,645. Direct and indirect costs were 78.3% and 21.7% respectively. Laboratory consumable costs by 37% and personnel costs by 36.3% had the largest share of the costing. Also, group of hormone tests cost the most $147,741 (23.03%), and other tests group cost the least $3,611 (0.56%). Also after calculating the cost of laboratory services, a comparison was made between the calculated price and the private sector’s tariffs in 2015. Conclusion This study showed that there was a difference between costs and tariffs in the private laboratory. One way to overcome this problem is to increase the number of laboratory tests with regard to capacity of the laboratories. PMID:28607638

Cost-price estimation of clinical laboratory services based on activity-based costing: A case study from a developing country.

PubMed

Mouseli, Ali; Barouni, Mohsen; Amiresmaili, Mohammadreza; Samiee, Siamak Mirab; Vali, Leila

2017-04-01

It is believed that laboratory tariffs in Iran don't reflect the real costs. This might expose private laboratories at financial hardship. Activity Based Costing is widely used as a cost measurement instrument to more closely approximate the true cost of operations. This study aimed to determine the real price of different clinical tests of a selected private clinical laboratory. This study was a cross sectional study carried out in 2015. The study setting was the private laboratories in the city of Kerman, Iran. Of 629 tests in the tariff book of the laboratory (relative value), 188 tests were conducted in the laboratory that used Activity Based Costing (ABC) methodology to estimate cost-price. Analyzing and cost-price estimating of laboratory services were performed by MY ABCM software Version 5.0. In 2015, the total costs were $641,645. Direct and indirect costs were 78.3% and 21.7% respectively. Laboratory consumable costs by 37% and personnel costs by 36.3% had the largest share of the costing. Also, group of hormone tests cost the most $147,741 (23.03%), and other tests group cost the least $3,611 (0.56%). Also after calculating the cost of laboratory services, a comparison was made between the calculated price and the private sector's tariffs in 2015. This study showed that there was a difference between costs and tariffs in the private laboratory. One way to overcome this problem is to increase the number of laboratory tests with regard to capacity of the laboratories.

Studying Human Disease Genes in "Caenorhabditis Elegans": A Molecular Genetics Laboratory Project

ERIC Educational Resources Information Center

Cox-Paulson, Elisabeth A.; Grana, Theresa M.; Harris, Michelle A.; Batzli, Janet M.

2012-01-01

Scientists routinely integrate information from various channels to explore topics under study. We designed a 4-wk undergraduate laboratory module that used a multifaceted approach to study a question in molecular genetics. Specifically, students investigated whether "Caenorhabditis elegans" can be a useful model system for studying genes…

Chambers versus Relaxed Eddy Accumulation: an intercomparison study of two methods for short-term measurements of biogenic CO2 fluxes

NASA Astrophysics Data System (ADS)

Jasek, Alina; Zimnoch, Miroslaw; Gorczyca, Zbigniew; Chmura, Lukasz; Necki, Jaroslaw

2014-05-01

The presented work is a part of comprehensive study aimed at thorough characterization of carbon cycle in the urban environment of Krakow, southern Poland. In the framework of this study two independent methods were employed to quantify biogenic CO2 flux in the city: (i) closed chambers, and (ii) Relaxed Eddy Accumulation (REA). The results of a three-day intensive intercomparison campaign performed in July 2013 and utilizing both measurement methods are reported here. The chamber method is a widely used approach for measurements of gas exchange between the soil and the atmosphere. The system implemented in this study consisted of a single chamber operating in a closed-dynamic mode, combined with Vaisala CarboCAP infrared CO2 sensor in a mobile setup. An alternative flux measurement method, covering larger area is represented by REA, which is a modification of the eddy covariance method. It consists of a 3D anemometer (Gill Windmaster Pro) and the system collecting updraft and downdraft samples to 5-litre Tedlar bags. The CO2 mixing ratios in the collected samples are measured by Picarro G2101i analyzer. The setup consists of two sets of bags so that the sampling can be performed continuously with 15-min temporal resolution. A 48-hectares open meadow located close the city center was chosen as a test site for comparison of the two methods of CO2 flux measurements outlined above. In the middle of the meadow a 3-metre high tripod was installed with the anemometer and REA inlet system. For a period of 46 hours the system was measuring net CO2 flux from the surrounding area. A meteorological conditions and intensity of photosynthetically active radiation (PAR) were also recorded. In the same time, CO2 flux from several points around the REA inlet was measured with the chamber system, resulting in 93 values for both respiration and net CO2 flux. Chamber results show rather homogenous distribution of the soil CO2 flux (the mean value equal to 40.9 ± 2.2 mmol/m2h), with

The Laboratory for Terrestrial Physics

NASA Technical Reports Server (NTRS)

2003-01-01

The Laboratory for Terrestrial Physics is dedicated to the advancement of knowledge in Earth and planetary science, by conducting innovative research using space technology. The Laboratory's mission and activities support the work and new initiatives at NASA's Goddard Space Flight Center (GSFC). The Laboratory's success contributes to the Earth Science Directorate as a national resource for studies of Earth from Space. The Laboratory is part of the Earth Science Directorate based at the GSFC in Greenbelt, MD. The Directorate itself is comprised of the Global Change Data Center (GCDC), the Space Data and Computing Division (SDCD), and four science Laboratories, including Laboratory for Terrestrial Physics, Laboratory for Atmospheres, and Laboratory for Hydrospheric Processes all in Greenbelt, MD. The fourth research organization, Goddard Institute for Space Studies (GISS), is in New York, NY. Relevant to NASA's Strategic Plan, the Laboratory ensures that all work undertaken and completed is within the vision of GSFC. The philosophy of the Laboratory is to balance the completion of near term goals, while building on the Laboratory's achievements as a foundation for the scientific challenges in the future.