Science.gov

Sample records for air temperature annual

  1. Change point analysis of mean annual air temperature in Iran

    NASA Astrophysics Data System (ADS)

    Shirvani, A.

    2015-06-01

    The existence of change point in the mean of air temperature is an important indicator of climate change. In this study, Student's t parametric and Mann-Whitney nonparametric Change Point Models (CPMs) were applied to test whether a change point has occurred in the mean of annual Air Temperature Anomalies Time Series (ATATS) of 27 synoptic stations in different regions of Iran for the period 1956-2010. The Likelihood Ratio Test (LRT) was also applied to evaluate the detected change points. The ATATS of all stations except Bandar Anzali and Gorgan stations, which were serially correlated, were transformed to produce an uncorrelated pre-whitened time series as an input file for the CPMs and LRT. Both the Student's t and Mann-Whitney CPMs detected the change point in the ATATS of (a) Tehran Mehrabad, Abadan, Kermanshah, Khoramabad and Yazd in 1992, (b) Mashhad and Tabriz in 1993, (c) Bandar Anzali, Babolsar and Ramsar in 1994, (d) Kerman and Zahedan in 1996 at 5% significance level. The likelihood ratio test shows that the ATATS before and after detected change points in these 12 stations are normally distributed with different means. The Student's t and Mann-Whitney CPMs suggested different change points for individual stations in Bushehr, Bam, Shahroud, and Gorgan. However, the LRT confirmed the change points in these four stations as 1997, 1996, 1993, and 1996, respectively. No change points were detected in the remaining 11 stations.

  2. Annual and seasonal air temperature trend patterns of climate change and urbanization effects in relation to air pollutants in Turkey

    NASA Astrophysics Data System (ADS)

    Tayanç, Mete; Karaca, Mehmet; Yenigün, Orhan

    1997-01-01

    With a view to estimating climate change and ifs urban-induced bias in selected Turkish cities, we have used data from the period 1951 to 1990 recorded by 54 climate stations, four of which are corrected for their inhomogeneities. Two sets are produced; S1, including the large urban stations, and S2, consisting of rural, small urban and medium urban stations. Normalized Kendall trend test coefficients with a spatial prediction scheme, kriging, are used to construct spatial patterns of both sets together and separately. Results reveal a statistically significant cooling in mean temperatures mostly in northern regions and warming in minimum temperatures specific to large urban areas. Seasonal analysis shows that most of this cooling has been occurring in the summer and urban warming in the spring. The causes of cooling is investigated in relation to some air pollutants, SO2 and particulate matter (PM). Linear regressions performed on the time series resulted in a significant urban bias of 0.24°C per 40 years on mean temperatures and 0.56°C/40 years on minimum temperatures. In association with the above results, a decrease in the temperature range of 0.48°C over the period owing to urban bias was found. A 0.24°C urban bias magnitude of mean temperature trends is much greater than the results found on other three regions of the Earth [Jones et al., 1990]. An overall average cooling in mean temperatures, -0.07°C per decade, detected here is the same as Nasrallah and Balling's [1993] average result for the two grid points located over Turkey.

  3. Effects of ambient air temperature, humidity and rainfall on annual survival of adult little penguins Eudyptula minor in southeastern Australia.

    PubMed

    Ganendran, L B; Sidhu, L A; Catchpole, E A; Chambers, L E; Dann, P

    2016-08-01

    Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival. PMID:26698160

  4. Effects of ambient air temperature, humidity and rainfall on annual survival of adult little penguins Eudyptula minor in southeastern Australia

    NASA Astrophysics Data System (ADS)

    Ganendran, L. B.; Sidhu, L. A.; Catchpole, E. A.; Chambers, L. E.; Dann, P.

    2015-12-01

    Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival.

  5. Effects of ambient air temperature, humidity and rainfall on annual survival of adult little penguins Eudyptula minor in southeastern Australia

    NASA Astrophysics Data System (ADS)

    Ganendran, L. B.; Sidhu, L. A.; Catchpole, E. A.; Chambers, L. E.; Dann, P.

    2016-08-01

    Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival.

  6. Modeling monthly mean air temperature for Brazil

    NASA Astrophysics Data System (ADS)

    Alvares, Clayton Alcarde; Stape, José Luiz; Sentelhas, Paulo Cesar; de Moraes Gonçalves, José Leonardo

    2013-08-01

    Air temperature is one of the main weather variables influencing agriculture around the world. Its availability, however, is a concern, mainly in Brazil where the weather stations are more concentrated on the coastal regions of the country. Therefore, the present study had as an objective to develop models for estimating monthly and annual mean air temperature for the Brazilian territory using multiple regression and geographic information system techniques. Temperature data from 2,400 stations distributed across the Brazilian territory were used, 1,800 to develop the equations and 600 for validating them, as well as their geographical coordinates and altitude as independent variables for the models. A total of 39 models were developed, relating the dependent variables maximum, mean, and minimum air temperatures (monthly and annual) to the independent variables latitude, longitude, altitude, and their combinations. All regression models were statistically significant ( α ≤ 0.01). The monthly and annual temperature models presented determination coefficients between 0.54 and 0.96. We obtained an overall spatial correlation higher than 0.9 between the models proposed and the 16 major models already published for some Brazilian regions, considering a total of 3.67 × 108 pixels evaluated. Our national temperature models are recommended to predict air temperature in all Brazilian territories.

  7. Estimating the Mean Annual Surface Air Temperature at Armagh Observatory, Northern Ireland, and the Global Land-Ocean Temperature Index for Sunspot Cycle 24, the Current Ongoing Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2013-01-01

    As noted by Gray et al., Sir William Herschel was the first to suggest a possible close connection between the Sun and the Earth’s climate. The Sun, being the source of energy that impacts and drives the Earth’s climate system, displays a variety of changes over both short and long term time scales, the most obvious examples being the somewhat regular waxing and waning of sunspots with time (i.e., the sunspot cycle (SC)), first described by Samuel Heinrich Schwabe, a German apothecary and amateur astronomer who observed the Sun from Dessau, Germany, and the now well established variation of the Sun’s irradiance over the SC. Other factors related to the SC have been linked to changes in climate as well. Some of these other factors include the role of cosmic rays and the solar wind (i.e., the geomagnetic cycle) on climate, as well as the apparent close association between trends in global and northern hemispheric temperature and the length of the SC, although some investigators have described the inferred association between climate and, in particular, SC length as now being weak. More recently, Solheim et al. have reported on the relation between SC length and the average temperature in the same and immediately following SC for a number of meteorological stations in Norway and in the North Atlantic region. They noted that while they found no significant trend (correlation) between SC length and the average temperature when measured for the same cycle, in contrast, they found a significant negative trend when SC length was compared with the following cycle’s average temperature. From this observation, they suggested that average northern hemispheric temperature during the present ongoing SC (SC24) will be lower by about 0.9 °C than was seen in SC23 (spanning 1996–2007, based on yearly averages of sunspot number (SSN), and onset for SC24 occurring in 2008). The purpose of this Technical Publication (TP) is to examine the annual variations of the Armagh

  8. 40 CFR 58.15 - Annual air monitoring data certification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Annual air monitoring data certification. 58.15 Section 58.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) AMBIENT AIR QUALITY SURVEILLANCE Monitoring Network § 58.15 Annual air monitoring...

  9. 40 CFR 58.15 - Annual air monitoring data certification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Annual air monitoring data certification. 58.15 Section 58.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) AMBIENT AIR QUALITY SURVEILLANCE Monitoring Network § 58.15 Annual air monitoring...

  10. 40 CFR 51.320 - Annual air quality data report.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Annual air quality data report. 51.320... REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Reports Air Quality Data Reporting § 51.320 Annual air quality data report. The requirements for reporting air quality data...

  11. 40 CFR 51.320 - Annual air quality data report.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 2 2011-07-01 2011-07-01 false Annual air quality data report. 51.320... REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Reports Air Quality Data Reporting § 51.320 Annual air quality data report. The requirements for reporting air quality data...

  12. 40 CFR 51.320 - Annual air quality data report.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Annual air quality data report. 51.320... REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Reports Air Quality Data Reporting § 51.320 Annual air quality data report. The requirements for reporting air quality data...

  13. 40 CFR 51.320 - Annual air quality data report.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 2 2013-07-01 2013-07-01 false Annual air quality data report. 51.320... REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Reports Air Quality Data Reporting § 51.320 Annual air quality data report. The requirements for reporting air quality data...

  14. 40 CFR 51.320 - Annual air quality data report.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Annual air quality data report. 51.320... REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF IMPLEMENTATION PLANS Reports Air Quality Data Reporting § 51.320 Annual air quality data report. The requirements for reporting air quality data...

  15. Total cloudiness over the Arctic in winter: an intercomparison of different climatologies, an assessment of inter-annual variability and connection with surface air temperature

    NASA Astrophysics Data System (ADS)

    Chernokulsky, Alexander; Esau, Igor; Mokhov, Igor I.

    2013-04-01

    An increase of air temperature in the Arctic is accompanied with changes in other climate variables, particularly with a decrease of the Arctic sea ice extent and cloud cover changes. The sensitivity of the cloud radiative forcing is about 1 Watt per square meter per 1% of cloud cover in the Arctic. Thus, relatively small changes in cloud fraction could result in an sufficient climate forcing. Considering an importance of clouds in the Arctic, it is crucial to know exactly when and where clouds exist and how cloud cover is changing in time. Here, we analyze climatology of winter cloudiness over the entire Arctic (north of 60N), its interannual variability in the Norwegian Sea - Kara Sea region and its connection with surface air temperature. Based an intercomparison of 16 cloud climatologies (including satellite and surface observations as well as reanalyses data), we show significant distinctions among different cloud climatologies based on various observations and reanalyses. Clouds cover 55-72% of the Arctic according to surface and satellite observations and 47-93% according to reanalyses. Coefficient of spatial correlation of different observation-derived cloud climatologies varies from 0.7 to 0.95 over the ocean and from 0.3 to 0.75 over land and it is negative for particular reanalyses. In general, winter cloud climatologies from reanalyses are in a bad agreement with observational ones. We use long-term visual observations from Norwegian and Russian meteorological stations in the Norwegian Sea - Kara Sea region to assess cloud interannual variability during the last century and its connection with surface air temperature. We find that a number of warm and overcast winter days is higher in the recent warming than during the cooling of 60-80s years of the 20th century. However, the early 20th century warming was even more cloudy then the recent warming. In general, surface air temperature in the ice band regions and during the cold periods is more sensitive

  16. Is Air Temperature Enough to Predict Lake Surface Temperature?

    NASA Astrophysics Data System (ADS)

    Piccolroaz, S.; Toffolon, M.; Majone, B.

    2014-12-01

    Lake surface water (LST) is a key factor that controls most of the physical and ecological processes occurring in lakes. Reliable estimates are especially important in the light of recent studies, which revealed that inland water bodies are highly sensitive to climate, and are rapidly warming throughout the world. However, an accurate estimation of LST usually requires a significant amount of information that is not always available. In this work, we present an application of air2water, a lumped model that simulates LST as a function of air temperature only. In addition, air2water allows for a qualitative evaluation of the depth of the epilimnion during the annual stratification cycle. The model consists in a simplification of the complete heat budget of the well-mixed surface layer, and has a few parameters (from 4 to 8 depending on the version) that summarize the role of the different heat flux components. Model calibration requires only air and water temperature data, possibly covering sufficiently long historical periods in order to capture inter-annual variability and long-term trends. During the calibration procedure, the information included in input data is retrieved to directly inform model parameters, which can be used to classify the thermal behavior of the lake. In order to investigate how thermal dynamics are related to morphological features, the model has been applied to 14 temperate lakes characterized by different morphological and hydrological conditions, by different sources of temperature data (buoys, satellite), and by variable frequency of acquisition. A good agreement between observed and simulated LST has been achieved, with a RMSE in the order of 1°C, which is fully comparable to the performances of more complex process-based models. This application allowed for a deeper understanding of the thermal response of lakes as a function of their morphology, as well as for specific analyses as for example the investigation of the exceptional

  17. 40 CFR 58.15 - Annual air monitoring data certification.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Administrator (through the appropriate Regional Office) an annual summary report of all the ambient air quality data collected at all SLAMS and at SPM stations using FRM, FEM, or ARMs. The annual report(s) shall be submitted for data collected from January 1 to December 31 of the previous year. The annual summary...

  18. 40 CFR 58.15 - Annual air monitoring data certification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Administrator (through the appropriate Regional Office) an annual summary report of all the ambient air quality data collected at all SLAMS and at SPM stations using FRM, FEM, or ARMs. The annual report(s) shall be submitted for data collected from January 1 to December 31 of the previous year. The annual summary...

  19. Surface Temperature variability from AIRS.

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, A.; Dang, V. T.; Aumann, H. H.

    2015-12-01

    To address the existence and possible causes of the climate hiatus in the Earth's global temperature we investigate the trends and variability in the surface temperature using retrievals obtained from the measurements by the Atmospheric Infrared Sounder (AIRS) and its companion instrument, the Advanced Microwave Sounding Unit (AMSU), onboard of Aqua spacecraft in 2002-2014for the day and night conditions. The data used are L3 monthly means on a 1x1degree spatial grid. We separate the land and ocean temperatures, as well as temperatures in Artic, Antarctic and desert regions. We compare the satellite data with the new surface data produced by Karl et al. (2015) who denies the reality of the climate hiatus. The difference in the regional trends can help to explain why the global surface temperature remains almost unchanged but the frequency of occurrence of the extreme events increases under rising anthropogenic forcing. The day-night difference is an indicator of the anthropogenic trend. This work was supported by the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  20. Effect of Ambient Design Temperature on Air-Cooled Binary Plant Output

    SciTech Connect

    Dan Wendt; Greg Mines

    2011-10-01

    Air-cooled binary plants are designed to provide a specified level of power production at a particular air temperature. Nominally this air temperature is the annual mean or average air temperature for the plant location. This study investigates the effect that changing the design air temperature has on power generation for an air-cooled binary plant producing power from a resource with a declining production fluid temperature and fluctuating ambient temperatures. This analysis was performed for plants operating both with and without a geothermal fluid outlet temperature limit. Aspen Plus process simulation software was used to develop optimal air-cooled binary plant designs for specific ambient temperatures as well as to rate the performance of the plant designs at off-design operating conditions. Results include calculation of annual and plant lifetime power generation as well as evaluation of plant operating characteristics, such as improved power generation capabilities during summer months when electric power prices are at peak levels.

  1. Crowdsourcing urban air temperatures from smartphone battery temperatures

    NASA Astrophysics Data System (ADS)

    Overeem, Aart; Robinson, James C. R.; Leijnse, Hidde; Steeneveld, Gert-Jan; Horn, Berthold K. P.; Uijlenhoet, Remko

    2014-05-01

    Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. It has been shown that a straightforward heat transfer model can be employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real-time temperature monitoring in densely populated areas. Battery temperature data were collected by users of an Android application for cell phones (opensignal.com). The application automatically sends battery temperature data to a server for storage. In this study, battery temperatures are averaged in space and time to obtain daily averaged battery temperatures for each city separately. A regression model, which can be related to a physical model, is employed to retrieve daily air temperatures from battery temperatures. The model is calibrated with observed air temperatures from a meteorological station of an airport located in or near the city. Time series of air temperatures are obtained for each city for a period of several months, where 50% of the data is for independent verification. The methodology has been applied to Buenos Aires, London, Los Angeles, Paris, Mexico City, Moscow, Rome, and Sao Paulo. The evolution of the retrieved air temperatures often correspond well with the observed ones. The mean absolute error of daily air temperatures is less than 2 degrees Celsius, and the bias is within 1 degree

  2. Crowdsourcing urban air temperatures from smartphone battery temperatures

    NASA Astrophysics Data System (ADS)

    Overeem, A.; Robinson, J. C. R.; Leijnse, H.; Steeneveld, G. J.; Horn, B. K. P.; Uijlenhoet, R.

    2013-08-01

    Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. A straightforward heat transfer model is employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real-time temperature monitoring in densely populated areas.

  3. Controlled-Temperature Hot-Air Gun

    NASA Technical Reports Server (NTRS)

    Munoz, M. C.

    1986-01-01

    Materials that find applications in wind tunnels first tested in laboratory. Hot-Air Gun differs from commercial units in that flow rate and temperature monitored and controlled. With typical compressed-airsupply pressure of 25 to 38 psi (170 to 260 kPa), flow rate and maximum temperature are 34 stdft3/min (0.96 stdm3/min) and 1,090 degrees F (590 degrees C), respectively. Resembling elaborate but carefully regulated hot-air gun, setup used to apply blasts of air temperatures above 1,500 degrees F (815 degrees C) to test specimens.

  4. Climatology of upper air temperature in the Eastern Mediterranean region

    NASA Astrophysics Data System (ADS)

    Philandras, C. M.; Nastos, P. T.; Kapsomenakis, I. N.; Repapis, C. C.

    2015-01-01

    The goal of this study is to contribute to the climatology of upper air temperature in the Mediterranean region, during the period 1965-2011. For this purpose, both radiosonde recordings and gridded reanalysis datasets of upper air temperature from National Center for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) were used for seven barometric levels at 850 hPa, 700 hPa, 500 hPa, 300 hPa, 200 hPa, 150 hPa and 100 hPa. Trends and variability of upper air temperature were analyzed on annual and seasonal basis. Further, the impact of atmospheric circulation, by means of correlation between upper air temperature at different barometric levels and specific climatic indices such as Mediterranean Oscillation Index (MOI), North Sea Caspian Pattern Index (NCPI) and North Atlantic Oscillation Index (NAOI), was also quantified. Our findings have given evidence that air temperature is increasing at a higher rate in lower/middle troposphere against upper, and this is very likely due to increasing greenhouse gas concentrations.

  5. Air separation with temperature and pressure swing

    DOEpatents

    Cassano, Anthony A.

    1986-01-01

    A chemical absorbent air separation process is set forth which uses a temperature swing absorption-desorption cycle in combination with a pressure swing wherein the pressure is elevated in the desorption stage of the process.

  6. Sandia National Laboratories, California Air Quality Program : annual report.

    SciTech Connect

    Shih, Richard; Gardizi, Leslee P.

    2007-05-01

    The annual program report provides detailed information about all aspects of the SNL/CA Air Quality Program. It functions as supporting documentation to the SNL/CA Environmental Management System Program Manual. The program report describes the activities undertaken during the past year, and activities planned in future years to implement the Air Quality Program, one of six programs that supports environmental management at SNL/CA.

  7. Sandia National Laboratories, California Air Quality Program annual report.

    SciTech Connect

    Gardizi, Leslee P.; Smith, Richard

    2009-06-01

    The annual program report provides detailed information about all aspects of the SNL/CA Air Quality Program. It functions as supporting documentation to the SNL/CA Environmental Management System Program Manual. The program report describes the activities undertaken during the past year, and activities planned in future years to implement the Air Quality Program, one of six programs that supports environmental management at SNL/CA.

  8. Crowdsourcing urban air temperature measurements using smartphones

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-10-01

    Crowdsourced data from cell phone battery temperature sensors could be used to contribute to improved real-time, high-resolution air temperature estimates in urban areas, a new study shows. Temperature observations in cities are in some cases currently limited to a few weather stations, but there are millions of smartphone users in many cities. The batteries in cell phones have temperature sensors to avoid damage to the phone.

  9. Nowcasting daily minimum air and grass temperature

    NASA Astrophysics Data System (ADS)

    Savage, M. J.

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  10. Nowcasting daily minimum air and grass temperature.

    PubMed

    Savage, M J

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient (b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  11. Evaluation of Annual Performance of Multi-type Air-Conditioners for Buildings

    NASA Astrophysics Data System (ADS)

    Hirota, Masafumi; Watanabe, Choyu; Furukawa, Masahide; Nagamatsu, Katsuaki

    The partial load performance tests of multi-type package air-conditioners for buildings powered by electric motors, the rating cooling performance of which was 56 kW, were carried out by using the air-enthalpy method testing apparatus. The coefficient of performance (COP) and annual energy consumption measured by those tests were closely compared with those estimated from the current calculating method (JIS B 8616:2006). It was found that the performance of the air-conditioner changes depending on the outdoor air temperature and the indoor thermal load. The current calculating method could not reproduce the deteriorations of COP that appeared under the low thermal load condition in both the cooling and heating seasons. As a result it seriously underestimated the annual energy consumption; the error amounted to as large as about 20 % of the measured annual electric power consumption. Based on these results, we have proposed new testing conditions for the performance evaluation and a calculation method of the annual energy consumption that can improve the accuracy of the estimation of the annual energy consumption.

  12. Temperature Tunable Air-Gap Etalon Filter

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Stephen, Mark A.; Lunt, David L.

    1998-01-01

    We report on experimental measurements of a temperature tuned air-gap etalon filter. The filter exhibits temperature dependent wavelength tuning of 54 pm/C. It has a nominal center wavelength of 532 nm. The etalon filter has a 27 pm optical bandpass and 600 pm free spectral range (finesse approximately 22). The experimental results are in close agreement with etalon theory.

  13. Annual sea ice. An air-sea gas exchange moderator

    SciTech Connect

    Gosink, T.A.; Kelley, J.J.

    1982-01-01

    Arctic annual sea ice, particularly when it is relatively warm (> -15/sup 0/C) permits significant gas exchange between the sea and air throughout the entire year. Sea ice, particularly annual sea ice, differs from freshwater ice with respect to its permeability to gases. The presence of brine allows for significant air-sea-ice exchange of CO/sub 2/ throughout the winter, which may significantly affect the global carbon dioxide balance. Other trace gases are also noted to be enriched in sea ice, but less is known about their importance to air-sea-interactions at this time. Both physical and biological factors cause and modify evolution of gases from the surface of sea ice. Quantitative and qualitative descriptions of the nature and physical behavior of sea ice with respect to brine and gases are discussed.

  14. On the Trend of the Annual Mean, Maximum, and Minimum Temperature and the Diurnal Temperature Range in the Armagh Observatory, Northern Ireland, Dataset, 1844 -2012

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2013-01-01

    Examined are the annual averages, 10-year moving averages, decadal averages, and sunspot cycle (SC) length averages of the mean, maximum, and minimum surface air temperatures and the diurnal temperature range (DTR) for the Armagh Observatory, Northern Ireland, during the interval 1844-2012. Strong upward trends are apparent in the Armagh surface-air temperatures (ASAT), while a strong downward trend is apparent in the DTR, especially when the ASAT data are averaged by decade or over individual SC lengths. The long-term decrease in the decadaland SC-averaged annual DTR occurs because the annual minimum temperatures have risen more quickly than the annual maximum temperatures. Estimates are given for the Armagh annual mean, maximum, and minimum temperatures and the DTR for the current decade (2010-2019) and SC24.

  15. Undulator Hall Air Temperature Fault Scenarios

    SciTech Connect

    Sevilla, J.; Welch, J.; /SLAC

    2010-11-17

    Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.

  16. Annual and Semi-Annual Temperature Oscillations in the Upper Mesosphere

    NASA Technical Reports Server (NTRS)

    Niciejewski, R. J.; Killeen, T. L.

    1995-01-01

    Fourier transform spectrometer observations of the mesosphere have been performed at the University of Michigan (latitude: 42.5 N) on a long term basis. A database of near infrared Meinel hydroxyl spectra has been accumulated from which rotational temperatures have been determined. Harmonic analysis of one-day averaged temperatures for the period 1992.0 to 1994.5 has shown a distinct annual and semi-annual variation. Subsequent fitting of a five term periodic function characterizing the annual and semi-annual temperature oscillations to the daily averaged temperatures was performed. The resultant mean temperature and the amplitudes and phases of the annual and semi-annual variations are shown to coincide with an emission height slightly above 85 km which is consistent with the mean rocket derived altitude for peak nocturnal hydroxyl emission.

  17. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  18. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  19. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  20. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  1. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  2. Identifying Modes of Temperature Variability Using AIRS Data.

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, A.; Aumann, H. H.; Yung, Y.

    2007-12-01

    We use the Atmospheric Infrared Sounder (AIRS) and Advance Microwave Sounding Unit (AMSU) data obtained on Aqua spacecraft to study mid-tropospheric temperature variability between 2002-2007. The analysis is focused on daily zonal means of the AIRS channel at 2388 1/cm in the CO2 R-branch and the AMSU channel #5 in the 57 GHz Oxygen band, both with weighting function peaking in the mid-troposphere (400 mb) and the matching sea surface temperature from NCEP (Aumann et al., 2007). Taking into account the nonlinear and non- stationary behavior of the temperature we apply the Empirical Mode Decomposition (Huang et al., 1998) to better separate modes of variability. All-sky (cloudy) and clear sky, day and night data are analyzed. In addition to the dominant annual variation, which is nonlinear and latitude dependent, we identified the modes with higher frequency and inter-annual modes. Some trends are visible and we apply stringent criteria to test their statistical significance. References: Aumann, H. H., D. T. Gregorich, S. E. Broberg, and D. A. Elliott, Geophys. Res. Lett., 34, L15813, doi:10.1029/2006GL029191, 2007. Huang, N. E. Z. Shen, S. R. Long, M. C. Wu, H. H. Shih, Q. Zheng, N.-C. Yen, C. C. Tung, and H. H. Liu, Proc. R. Soc. Lond., A 454, 903-995, 1998.

  3. Compressed air energy storage technology program. Annual report for 1980

    SciTech Connect

    Kannberg, L.D.

    1981-06-01

    All of the major research funded under the Compressed Air Energy Storage Technology Program during the period March 1980 to March 1981 is described. This annual report is divided into two segments: Reservoir Stability Studies and Second-Generation Concepts Studies. The first represents research performed to establish stability criteria for CAES reservoirs while the second reports progress on research performed on second-generation CAES concepts. The report consists of project reports authored by research engineers and scientists from PNL and numerous subcontractors including universities, architect-engineering, and other private firms.

  4. Trends in Surface Temperature from AIRS.

    NASA Astrophysics Data System (ADS)

    Ruzmaikin, A.; Aumann, H. H.

    2014-12-01

    To address possible causes of the current hiatus in the Earth's global temperature we investigate the trends and variability in the surface temperature using retrievals obtained from the measurements by the Atmospheric Infrared Sounder (AIRS) and its companion instrument, the Advanced Microwave Sounding Unit (AMSU), onboard of Aqua spacecraft in 2002-2014. The data used are L3 monthly means on a 1x1degree spatial grid. We separate the land and ocean temperatures, as well as temperatures in Artic, Antarctic and desert regions. We find a monotonic positive trend for the land temperature but not for the ocean temperature. The difference in the regional trends can help to explain why the global surface temperature remains almost unchanged but the frequency of occurrence of the extreme events increases under rising anthropogenic forcing. The results are compared with the model studies. This work was supported by the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  5. Hot, cold, and annual reference atmospheres for Edwards Air Force Base, California (1975 version)

    NASA Technical Reports Server (NTRS)

    Johnson, D. L.

    1975-01-01

    Reference atmospheres pertaining to summer (hot), winter (cold), and mean annual conditions for Edwards Air Force Base, California, are presented from surface to 90 km altitude (700 km for the annual model). Computed values of pressure, kinetic temperature, virtual temperature, and density and relative differences percentage departure from the Edwards reference atmospheres, 1975 (ERA-75) of the atmospheric parameters versus altitude are tabulated in 250 m increments. Hydrostatic and gas law equations were used in conjunction with radiosonde and rocketsonde thermodynamic data in determining the vertical structure of these atmospheric models. The thermodynamic parameters were all subjected to a fifth degree least-squares curve-fit procedure, and the resulting coefficients were incorporated into Univac 1108 computer subroutines so that any quantity may be recomputed at any desired altitude using these subroutines.

  6. 14 CFR 23.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 23... Powerplant Powerplant Controls and Accessories § 23.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature control for each engine....

  7. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  8. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  9. 14 CFR 23.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Carburetor air temperature controls. 23... Powerplant Powerplant Controls and Accessories § 23.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature control for each engine....

  10. 14 CFR 23.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Carburetor air temperature controls. 23... Powerplant Powerplant Controls and Accessories § 23.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature control for each engine....

  11. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  12. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  13. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  14. 14 CFR 23.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Carburetor air temperature controls. 23... Powerplant Powerplant Controls and Accessories § 23.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature control for each engine....

  15. 14 CFR 23.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Carburetor air temperature controls. 23... Powerplant Powerplant Controls and Accessories § 23.1157 Carburetor air temperature controls. There must be a separate carburetor air temperature control for each engine....

  16. Air temperature and precipitation data, Gulkana Glacier, Alaska, 1968-96

    USGS Publications Warehouse

    Kennedy, Ben W.; Mayo, Lawrence R.; Trabant, Dennis C.; March, Rod S.

    1997-01-01

    Daily, monthly, and annual average air temperature and precipitation-catch data were recorded at Gulkana Glacier basin, Alaska, between October 1967 and September 1996. The data set is important because it provides long-term climate information from the highest year-round climatological recording site in Alaska. The daily air temperature data set is 96 percent complete. The daily precipitation data set is 83 percent complete; precipitation data for 1993-96 are missing. Annual data summaries are calculated for each hydrologic year, October 1 through September 30, for years that have 12 months of data. Monthly precipitation-catch and average air temperature summaries are calculated for months with nine or fewer daily records missing. The average annual air temperature recorded at the site from hydrologic year 1968 through 1996 was -4.1 degrees Celsius. The coldest recorded year was 1972 with an average annual temperature of -6.7 degrees Celsius. The warmest year was 1981 with an average annual temperature of -2.6 degrees Celsius. January 1971 was the coldest month with an average temperature of -20.8 degrees Celsius. July 1989 was the warmest month with an average temperature of 8.7 degrees Celsius. January 17, 1971, was the coldest day with an average temperature of -35.0 degrees Celsius. June 15, 1969, was the warmest day with an average temperature of 16.4 degrees Celsius. The average annual precipitation catch recorded at the site from hydrologic year 1968 through 1992 was 1,020 millimeters. The highest annual precipitation catch recorded was 1,572 millimeters in 1981; the lowest was 555 millimeters in 1969. The highest recorded monthly precipitation catch was 448 millimeters in July 1981 and in several different months no precipitation was recorded. The highest daily precipitation catch was 99 millimeters on September 12, 1972, and on many different dates no precipitation was recorded. Because of low gage-catch efficiency the reported annual precipitation

  17. A simplified physically-based model to calculate surface water temperature of lakes from air temperature in climate change scenarios

    NASA Astrophysics Data System (ADS)

    Piccolroaz, S.; Toffolon, M.

    2012-12-01

    Modifications of water temperature are crucial for the ecology of lakes, but long-term analyses are not usually able to provide reliable estimations. This is particularly true for climate change studies based on Global Circulation Models, whose mesh size is normally too coarse for explicitly including even some of the biggest lakes on Earth. On the other hand, modeled predictions of air temperature changes are more reliable, and long-term, high-resolution air temperature observational datasets are more available than water temperature measurements. For these reasons, air temperature series are often used to obtain some information about the surface temperature of water bodies. In order to do that, it is common to exploit regression models, but they are questionable especially when it is necessary to extrapolate current trends beyond maximum (or minimum) measured temperatures. Moreover, water temperature is influenced by a variety of processes of heat exchange across the lake surface and by the thermal inertia of the water mass, which also causes an annual hysteresis cycle between air and water temperatures that is hard to consider in regressions. In this work we propose a simplified, physically-based model for the estimation of the epilimnetic temperature in lakes. Starting from the zero-dimensional heat budget, we derive a simplified first-order differential equation for water temperature, primarily forced by a seasonally varying external term (mainly related to solar radiation) and an exchange term explicitly depending on the difference between air and water temperatures. Assuming annual sinusoidal cycles of the main heat flux components at the atmosphere-lake interface, eight parameters (some of them can be disregarded, though) are identified, which can be calibrated if two temporal series of air and water temperature are available. We note that such a calibration is supported by the physical interpretation of the parameters, which provide good initial

  18. 2010 Annual NESHAPs Radioactive Air Annual Meeting Hosted in conjunction with the 55th HPS Meeting June 29, 2010

    SciTech Connect

    Barnett, J. M.; Vazquez, Gustavo A.; Anderson, Shauna V.

    2013-12-01

    This is a compilation of selected abstracts and presentations/posters from the 2010 Annual Health Physics Society (HPS) meeting held in Salt Lake City, UT and the presentations and information presented at the annual radioactive air NESHAP meeting held in conjunction with the HPS meeting. (CD-ROM)

  19. 40 CFR 60.2151 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air pollution control device inspection? 60.2151 Section 60.2151 Protection of Environment... annual air pollution control device inspection? On an annual basis (no more than 12 months following the previous annual air pollution control device inspection), you must complete the air pollution...

  20. 40 CFR 60.2151 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air pollution control device inspection? 60.2151 Section 60.2151 Protection of Environment... annual air pollution control device inspection? On an annual basis (no more than 12 months following the previous annual air pollution control device inspection), you must complete the air pollution...

  1. Comparison of Near-Surface Air Temperatures and MODIS Ice-Surface Temperatures at Summit, Greenland (2008-2013)

    NASA Technical Reports Server (NTRS)

    Shuman, Christopher A.; Hall, Dorothy K.; DiGirolamo, Nicolo E.; Mefford, Thomas K.; Schnaubelt, Michael J.

    2014-01-01

    We have investigated the stability of the MODerate resolution Imaging Spectroradiometer (MODIS) infrared-derived ice surface temperature (IST) data from Terra for use as a climate quality data record. The availability of climate quality air temperature data (TA) from a NOAA Global Monitoring Division observatory at Greenlands Summit station has enabled this high temporal resolution study of MODIS ISTs. During a 5 year period (July 2008 to August 2013), more than 2500 IST values were compared with 3-minute average TA values derived from the 1-minute data from NOAAs primary 2 m air temperature sensor. These data enabled an expected small offset between air and surface temperatures at this the ice sheet location to be investigated over multiple annual cycles.

  2. High Temperature Materials Laboratory third annual report

    SciTech Connect

    Tennery, V.J.; Foust, F.M.

    1990-12-01

    The High Temperature Materials Laboratory has completed its third year of operation as a designated DOE User Facility at the Oak Ridge National Laboratory. Growth of the user program is evidenced by the number of outside institutions who have executed user agreements since the facility began operation in 1987. A total of 88 nonproprietary agreements (40 university and 48 industry) and 20 proprietary agreements (1 university, 19 industry) are now in effect. Sixty-eight nonproprietary research proposals (39 from university, 28 from industry, and 1 other government facility) and 8 proprietary proposals were considered during this reporting period. Research projects active in FY 1990 are summarized.

  3. Recent trends in regional air temperature and precipitation and links to global climate change in the Maharlo watershed, Southwestern Iran

    NASA Astrophysics Data System (ADS)

    Abolverdi, Javad; Ferdosifar, Ghasem; Khalili, Davar; Kamgar-Haghighi, Ali Akbar; Abdolahipour Haghighi, Mohammad

    2014-11-01

    Trends in air temperature and precipitation data are investigated for linkages to global warming and climate change. After checking for serial correlation with trend-free pre-whitening procedure, the Mann-Kendall test is used to detect monotonic trends and the Mann-Whitney test is used for trend step change. The case study is Maharlo watershed, Southwestern Iran, representing a semi-arid environment. Data are for the 1951-2011 period, from four temperature sites and seven precipitation sites. A homogeneity test investigates regional similarity of the time series data. The results include mean annual, mean annual maximum and minimum and seasonal analysis of air temperature and precipitation data. Mean annual temperature results indicate an increasing trend, while a non-significant trend in precipitation is observed in all the stations. Furthermore, significant phase change was detected in mean annual air temperature trend of Shiraz station in 1977, indicating decreasing trend during 1951-1976 and increasing trend during 1977-2011. The annual precipitation analysis for Shiraz shows a non-significant decrease during 1951-1976 and 1977-2011. The result of homogeneity test reveals that the studied stations form one homogeneous region. While air temperature trends appear as regional linkage to global warming/global climate change, more definite outcome requires analysis of longer time series data on precipitation and air temperature.

  4. Air temperature variation across the seed cotton dryer mixpoint

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eighteen tests were conducted in six gins in the fall of 2008 to measure air temperature variation within various heated air seed cotton drying systems with the purpose of: checking validation of recommendations by a professional engineering society and measuring air temperature variation across the...

  5. Possible Economies in Air-Conditioning by Accepting Temperature Swings.

    ERIC Educational Resources Information Center

    Loudon, A. G.; Petherbridge, P.

    Public building air conditioning systems, which use constant and varying heat and cooling loads, are compared and investigated. Experiments indicated that constant temperature controls based on outside air temperature alone were inefficient. Ventilating a building with outside air and the methods of doing so are cited as being the most economical…

  6. 14 CFR 29.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 29.1157 Section 29.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 29.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  7. 14 CFR 25.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Carburetor air temperature controls. 25.1157 Section 25.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 25.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  8. 14 CFR 25.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Carburetor air temperature controls. 25.1157 Section 25.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 25.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  9. 14 CFR 29.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Carburetor air temperature controls. 29.1157 Section 29.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 29.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  10. 14 CFR 29.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Carburetor air temperature controls. 29.1157 Section 29.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 29.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  11. 14 CFR 29.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Carburetor air temperature controls. 29.1157 Section 29.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 29.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  12. 14 CFR 25.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Carburetor air temperature controls. 25.1157 Section 25.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 25.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  13. 14 CFR 25.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Carburetor air temperature controls. 25.1157 Section 25.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 25.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  14. 14 CFR 29.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Carburetor air temperature controls. 29.1157 Section 29.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 29.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  15. 14 CFR 25.1157 - Carburetor air temperature controls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Carburetor air temperature controls. 25.1157 Section 25.1157 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Accessories § 25.1157 Carburetor air temperature controls. There must be a separate carburetor air...

  16. AIR TEMPERATURE DISTRIBUTION IN SEED COTTON DRYING SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ten tests were conducted in the fall of 2007 to measure air temperature variation within various heated air seed cotton drying systems with the purpose of: checking validation of recommendations by a professional engineering society and measuring air temperature variation across the airflow ductwork...

  17. Acoustic method for measuring air temperature and humidity in rooms

    NASA Astrophysics Data System (ADS)

    Kanev, N. G.

    2014-05-01

    A method is proposed to determine air temperature and humidity in rooms with a system of sound sources and receivers, making it possible to find the sound velocity and reverberation time. Nomograms for determining the air temperature and relative air humidity are constructed from the found sound velocity and time reverberation values. The required accuracy of measuring these parameters is estimated.

  18. Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes

    PubMed Central

    Bahn, M.; Reichstein, M.; Davidson, E. A.; Grünzweig, J.; Jung, M.; Carbone, M. S.; Epron, D.; Misson, L.; Nouvellon, Y.; Roupsard, O.; Savage, K.; Trumbore, S. E.; Gimeno, C.; Yuste, J. Curiel; Tang, J.; Vargas, R.; Janssens, I. A.

    2011-01-01

    Soil respiration (SR) constitutes the largest flux of CO2 from terrestrial ecosystems to the atmosphere. However, there still exist considerable uncertainties as to its actual magnitude, as well as its spatial and interannual variability. Based on a reanalysis and synthesis of 80 site-years for 57 forests, plantations, savannas, shrublands and grasslands from boreal to tropical climates we present evidence that total annual SR is closely related to SR at mean annual soil temperature (SRMAT), irrespective of the type of ecosystem and biome. This is theoretically expected for non water-limited ecosystems within most of the globally occurring range of annual temperature variability and sensitivity (Q10). We further show that for seasonally dry sites where annual precipitation (P) is lower than potential evapotranspiration (PET), annual SR can be predicted from wet season SRMAT corrected for a factor related to P/PET. Our finding indicates that it can be sufficient to measure SRMAT for obtaining a well constrained estimate of its annual total. This should substantially increase our capacity for assessing the spatial distribution of soil CO2 emissions across ecosystems, landscapes and regions, and thereby contribute to improving the spatial resolution of a major component of the global carbon cycle. PMID:23293656

  19. The influence of galactic cosmic ray on all India annual rainfall and temperature

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Sutapa; Pal, Jayanti; Guhathakurta, Suchandra

    2015-02-01

    The inverse relation between galactic cosmic ray (GCR) and sunspot numbers (SSN) suggests that the increase (decrease) in GCR count is linked with low (high) solar activity. The present study attempts to reveal the influence of GCR on all India annual rainfall and temperature during the period from 1953 to 2005. The inter-annual variation depicts that during the transition from maximum to minimum count of GCR, the rainfall anomaly shows alternative variation over India. Similar variation has also been observed for maximum temperature. Implementation of Fourier analysis shows an 11 year cycle of cosmic ray and depicts an increase in GCR count in the 11 year interval during the study period. The Fourier analysis of all India annual rainfall (AIR) and temperature also shows an 11 year cycle with a decreasing trend during the 11 year interval. The inter-decadal variation shows that during high GCR count there is a possibility of decrease in rainfall and minimum temperature but an increase in maximum temperature. The seasonal correlation shows a possible proportional association between cosmic ray and rainfall during the post monsoon season. The result further depicts that the sunspot number and temperature is positively correlated during the post-monsoon season. The correlation map of rainfall and temperature shows a meager but significant correlation with cosmic ray over some parts of West and East Indian coasts.

  20. The association of annual air pollution exposure with blood pressure among patients with sleep-disordered breathing.

    PubMed

    Liu, Wen-Te; Lee, Kang-Yun; Lee, Hsin-Chien; Chuang, Hsiao-Chi; Wu, Dean; Juang, Jer-Nan; Chuang, Kai-Jen

    2016-02-01

    While sleep-disordered breathing (SDB), high blood pressure (BP) and air pollution exposure have separately been associated with increased risk of cardiopulmonary mortality, the association linking air pollution exposure to BP among patients with sleep-disordered breathing is still unclear. We collected 3762 participants' data from the Taipei Medical University Hospital's Sleep Center and air pollution data from the Taiwan Environmental Protection Administration. Associations of 1-year mean criteria air pollutants [particulate matter with aerodynamic diameters ≤10 μm (PM10), particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5), nitrogen dioxide (NO2) and ozone (O3)] with systolic BP (SBP) and diastolic BP (DBP) were investigated by generalized additive models. After controlling for age, sex, body mass index (BMI), temperature and relative humidity, we observed that increases in air pollution levels were associated with decreased SBP and increased DBP. We also found that patients with apnea-hypopnea index (AHI) ≥30 showed a stronger BP response to increased levels of air pollution exposure than those with AHI<30. Stronger effects of air pollution exposure on BP were found in overweight participants than in participants with normal BMI. We concluded that annual exposure to air pollution was associated with change of BP among patients with sleep-disordered breathing. The association between annual air pollution exposure and BP could be modified by AHI and BMI. PMID:26580727

  1. Eleven years of ground-air temperature tracking over different land cover materials

    NASA Astrophysics Data System (ADS)

    Cermák, Vladimír; Dedecek, Petr; Bodri, Louise; Safanda, Jan; Kresl, Milan

    2015-04-01

    We have analyzed series of air, near surface and shallow ground temperatures under four different land covers, namely bare clayey soil, sand, grass and asphalt, collected between 2002 and 2013, monitored at the Geothermal Climate Change Observatory Sporilov. All obtained temperature series revealed a strong dependence of the subsurface thermal regime on the surface cover material. The ground "skin" temperatures are generally warmer than the surface air temperatures for all monitored surfaces; however they mutually differ significantly reflecting the nature of the land surface. Asphalt shows the highest temperatures, temperatures below the grassy surface are the lowest. A special interest was paid to the assessment of the "temperature offset", the difference between the surface ground temperature and the surface air temperature. Even when its instant value varies dramatically on both, daily and annual scale, by up to 30+ K, on a long time scale it is believed to be generally constant. The characteristic 2003-2013 mean offset values for the individual covers are following: asphalt 4.1 K, sand 1.6 K, clay 1.3 K and grass 0.2-0.3 K. All four surface covers revealed their daily and inter-annual cycles. Incident solar radiation is the primary variable in determining the amount of the temperature offset value and its time changes. A linear relationship between air-ground temperature differences and incident solar radiation was detected. The slope of the linear regression between both variables is clearly surface cover dependent. The greatest value of 3.3 K per 100 W.m-2 was found for asphalt, rates of 1.0 to 1.2 apply for bare soil and sand covers and negative slope of -0.44 K per 100 W.m-2 stands for grass, during the day or year the slope rates may vary extensively reflecting the periodic daily and/or annual cycle as well as the irregular instant deviations in solar radiation.

  2. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  3. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  4. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  5. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  6. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  7. On multi-timescale variability of temperature in China in modulated annual cycle reference frame

    NASA Astrophysics Data System (ADS)

    Qian, Cheng; Wu, Zhaohua; Fu, Congbin; Zhou, Tianjun

    2010-09-01

    The traditional anomaly (TA) reference frame and its corresponding anomaly for a given data span changes with the extension of data length. In this study, the modulated annual cycle (MAC), instead of the widely used climatological mean annual cycle, is used as an alternative reference frame for computing climate anomalies to study the multi-timescale variability of surface air temperature (SAT) in China based on homogenized daily data from 1952 to 2004. The Ensemble Empirical Mode Decomposition (EEMD) method is used to separate daily SAT into a high frequency component, a MAC component, an interannual component, and a decadal-to-trend component. The results show that the EEMD method can reflect historical events reasonably well, indicating its adaptive and temporally local characteristics. It is shown that MAC is a temporally local reference frame and will not be altered over a particular time span by an extension of data length, thereby making it easier for physical interpretation. In the MAC reference frame, the low frequency component is found more suitable for studying the interannual to longer timescale variability (ILV) than a 13-month window running mean, which does not exclude the annual cycle. It is also better than other traditional versions (annual or summer or winter mean) of ILV, which contains a portion of the annual cycle. The analysis reveals that the variability of the annual cycle could be as large as the magnitude of interannual variability. The possible physical causes of different timescale variability of SAT in China are further discussed.

  8. 40 CFR 60.2151 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air pollution control device inspection? 60.2151 Section 60.2151 Protection of Environment... Compliance Requirements § 60.2151 By what date must I conduct the annual air pollution control device inspection? On an annual basis (no more than 12 months following the previous annual air pollution...

  9. 40 CFR 60.2151 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air pollution control device inspection? 60.2151 Section 60.2151 Protection of Environment... Compliance Requirements § 60.2151 By what date must I conduct the annual air pollution control device inspection? On an annual basis (no more than 12 months following the previous annual air pollution...

  10. 40 CFR 60.4895 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Compliance Requirements § 60.4895 By what date must I conduct annual air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution... following the previous annual air pollution control device inspection. (b) Within 10 operating...

  11. 40 CFR 60.4895 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Compliance Requirements § 60.4895 By what date must I conduct annual air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution... following the previous annual air pollution control device inspection. (b) Within 10 operating...

  12. 40 CFR 60.2716 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air pollution control device inspection? 60.2716 Section 60.2716 Protection of Environment... Requirements § 60.2716 By what date must I conduct the annual air pollution control device inspection? On an annual basis (no more than 12 months following the previous annual air pollution control...

  13. 40 CFR 60.4895 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Compliance Requirements § 60.4895 By what date must I conduct annual air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution... following the previous annual air pollution control device inspection. (b) Within 10 operating...

  14. 40 CFR 60.4895 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Compliance Requirements § 60.4895 By what date must I conduct annual air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution... following the previous annual air pollution control device inspection. (b) Within 10 operating...

  15. Characterizing Air Temperature Changes in the Tarim Basin over 1960–2012

    PubMed Central

    Peng, Dongmei; Wang, Xiujun; Zhao, Chenyi; Wu, Xingren; Jiang, Fengqing; Chen, Pengxiang

    2014-01-01

    There has been evidence of warming rate varying largely over space and between seasons. However, little has been done to evaluate the spatial and temporal variability of air temperature in the Tarim Basin, northwest China. In this study, we collected daily air temperature from 19 meteorological stations for the period of 1960–2012, and analyzed annual mean temperature (AMT), the annual minimum (Tmin) and maximum temperature (Tmax), and mean temperatures of all twelve months and four seasons and their anomalies. Trend analyses, standard deviation of the detrended anomaly (SDDA) and correlations were carried out to characterize the spatial and temporal variability of various mean air temperatures. Our data showed that increasing trend was much greater in the Tmin (0.55°C/10a) than in the AMT (0.25°C/10a) and Tmax (0.12°C/10a), and the fluctuation followed the same order. There were large spatial variations in the increasing trends of both AMT (from −0.09 to 0.43 °C/10a) and Tmin (from 0.15 to 1.12°C/10a). Correlation analyses indicated that AMT had a significantly linear relationship with Tmin and the mean temperatures of four seasons. There were also pronounced changes in the monthly air temperature from November to March at decadal time scale. The seasonality (i.e., summer and winter difference) of air temperature was stronger during the period of 1960–1979 than over the recent three decades. Our preliminary analyses indicated that local environmental conditions (such as elevation) might be partly responsible for the spatial variability, and large scale climate phenomena might have influences on the temporal variability of air temperature in the Tarim Basin. In particular, there was a significant correlation between index of El Niño-Southern Oscillation (ENSO) and air temperature of May (P = 0.004), and between the index of Pacific Decadal Oscillation (PDO) and air temperature of July (P = 0.026) over the interannual to decadal time scales. PMID

  16. Characterizing air temperature changes in the Tarim Basin over 1960-2012.

    PubMed

    Peng, Dongmei; Wang, Xiujun; Zhao, Chenyi; Wu, Xingren; Jiang, Fengqing; Chen, Pengxiang

    2014-01-01

    There has been evidence of warming rate varying largely over space and between seasons. However, little has been done to evaluate the spatial and temporal variability of air temperature in the Tarim Basin, northwest China. In this study, we collected daily air temperature from 19 meteorological stations for the period of 1960-2012, and analyzed annual mean temperature (AMT), the annual minimum (T min) and maximum temperature (Tmax), and mean temperatures of all twelve months and four seasons and their anomalies. Trend analyses, standard deviation of the detrended anomaly (SDDA) and correlations were carried out to characterize the spatial and temporal variability of various mean air temperatures. Our data showed that increasing trend was much greater in the T min (0.55°C/10a) than in the AMT (0.25°C/10a) and Tmax (0.12°C/10a), and the fluctuation followed the same order. There were large spatial variations in the increasing trends of both AMT (from -0.09 to 0.43 °C/10a) and T min (from 0.15 to 1.12°C/10a). Correlation analyses indicated that AMT had a significantly linear relationship with T min and the mean temperatures of four seasons. There were also pronounced changes in the monthly air temperature from November to March at decadal time scale. The seasonality (i.e., summer and winter difference) of air temperature was stronger during the period of 1960-1979 than over the recent three decades. Our preliminary analyses indicated that local environmental conditions (such as elevation) might be partly responsible for the spatial variability, and large scale climate phenomena might have influences on the temporal variability of air temperature in the Tarim Basin. In particular, there was a significant correlation between index of El Niño-Southern Oscillation (ENSO) and air temperature of May (P = 0.004), and between the index of Pacific Decadal Oscillation (PDO) and air temperature of July (P = 0.026) over the interannual to decadal time scales. PMID:25375648

  17. Estimation of Surface Air Temperature from MODIS 1km Resolution Land Surface Temperature Over Northern China

    NASA Technical Reports Server (NTRS)

    Shen, Suhung; Leptoukh, Gregory G.; Gerasimov, Irina

    2010-01-01

    Surface air temperature is a critical variable to describe the energy and water cycle of the Earth-atmosphere system and is a key input element for hydrology and land surface models. It is a very important variable in agricultural applications and climate change studies. This is a preliminary study to examine statistical relationships between ground meteorological station measured surface daily maximum/minimum air temperature and satellite remotely sensed land surface temperature from MODIS over the dry and semiarid regions of northern China. Studies were conducted for both MODIS-Terra and MODIS-Aqua by using year 2009 data. Results indicate that the relationships between surface air temperature and remotely sensed land surface temperature are statistically significant. The relationships between the maximum air temperature and daytime land surface temperature depends significantly on land surface types and vegetation index, but the minimum air temperature and nighttime land surface temperature has little dependence on the surface conditions. Based on linear regression relationship between surface air temperature and MODIS land surface temperature, surface maximum and minimum air temperatures are estimated from 1km MODIS land surface temperature under clear sky conditions. The statistical errors (sigma) of the estimated daily maximum (minimum) air temperature is about 3.8 C(3.7 C).

  18. Surface air temperature and its changes over the past 150 years

    NASA Astrophysics Data System (ADS)

    Jones, P. D.; New, M.; Parker, D. E.; Martin, S.; Rigor, I. G.

    1999-05-01

    We review the surface air temperature record of the past 150 years, considering the homogeneity of the basic data and the standard errors of estimation of the average hemispheric and global estimates. We present global fields of surface temperature change over the two 20-year periods of greatest warming this century, 1925-1944 and 1978-1997. Over these periods, global temperatures rose by 0.37° and 0.32°C, respectively. The twentieth-century warming has been accompanied by a decrease in those areas of the world affected by exceptionally cool temperatures and to a lesser extent by increases in areas affected by exceptionally warm temperatures. In recent decades there have been much greater increases in night minimum temperatures than in day maximum temperatures, so that over 1950-1993 the diurnal temperature range has decreased by 0.08°C per decade. We discuss the recent divergence of surface and satellite temperature measurements of the lower troposphere and consider the last 150 years in the context of the last millennium. We then provide a globally complete absolute surface air temperature climatology on a 1° × 1° grid. This is primarily based on data for 1961-1990. Extensive interpolation had to be undertaken over both polar regions and in a few other regions where basic data are scarce, but we believe the climatology is the most consistent and reliable of absolute surface air temperature conditions over the world. The climatology indicates that the annual average surface temperature of the world is 14.0°C (14.6°C in the Northern Hemisphere (NH) and 13.4°C for the Southern Hemisphere). The annual cycle of global mean temperatures follows that of the land-dominated NH, with a maximum in July of 15.9°C and a minimum in January of 12.2°C.

  19. Solar Eclipse Effect on Shelter Air Temperature

    NASA Technical Reports Server (NTRS)

    Segal, M.; Turner, R. W.; Prusa, J.; Bitzer, R. J.; Finley, S. V.

    1996-01-01

    Decreases in shelter temperature during eclipse events were quantified on the basis of observations, numerical model simulations, and complementary conceptual evaluations. Observations for the annular eclipse on 10 May 1994 over the United States are presented, and these provide insights into the temporal and spatial changes in the shelter temperature. The observations indicated near-surface temperature drops of as much as 6 C. Numerical model simulations for this eclipse event, which provide a complementary evaluation of the spatial and temporal patterns of the temperature drops, predict similar decreases. Interrelationships between the temperature drop, degree of solar irradiance reduction, and timing of the peak eclipse are also evaluated for late spring, summer, and winter sun conditions. These simulations suggest that for total eclipses the drops in shelter temperature in midlatitudes can be as high as 7 C for a spring morning eclipse.

  20. 33 CFR 100.736 - Annual Fort Myers Beach air show; Fort Myers Beach, FL.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Annual Fort Myers Beach air show; Fort Myers Beach, FL. 100.736 Section 100.736 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Fort Myers Beach air show; Fort Myers Beach, FL. (a)(1) Regulated Area. The regulated area is formed...

  1. 33 CFR 100.736 - Annual Fort Myers Beach air show; Fort Myers Beach, FL.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Annual Fort Myers Beach air show; Fort Myers Beach, FL. 100.736 Section 100.736 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Fort Myers Beach air show; Fort Myers Beach, FL. (a)(1) Regulated Area. The regulated area is formed...

  2. 33 CFR 100.736 - Annual Fort Myers Beach air show; Fort Myers Beach, FL.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Annual Fort Myers Beach air show; Fort Myers Beach, FL. 100.736 Section 100.736 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Fort Myers Beach air show; Fort Myers Beach, FL. (a)(1) Regulated Area. The regulated area is formed...

  3. 33 CFR 100.736 - Annual Fort Myers Beach air show; Fort Myers Beach, FL.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Annual Fort Myers Beach air show; Fort Myers Beach, FL. 100.736 Section 100.736 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Fort Myers Beach air show; Fort Myers Beach, FL. (a)(1) Regulated Area. The regulated area is formed...

  4. 33 CFR 100.736 - Annual Fort Myers Beach air show; Fort Myers Beach, FL.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Annual Fort Myers Beach air show; Fort Myers Beach, FL. 100.736 Section 100.736 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Fort Myers Beach air show; Fort Myers Beach, FL. (a)(1) Regulated Area. The regulated area is formed...

  5. Comparison of MODIS Land Surface Temperature and Air Temperature over the Continental USA Meteorological Stations

    NASA Technical Reports Server (NTRS)

    Zhang, Ping; Bounoua, Lahouari; Imhoff, Marc L.; Wolfe, Robert E.; Thome, Kurtis

    2014-01-01

    The National Land Cover Database (NLCD) Impervious Surface Area (ISA) and MODIS Land Surface Temperature (LST) are used in a spatial analysis to assess the surface-temperature-based urban heat island's (UHIS) signature on LST amplitude over the continental USA and to make comparisons to local air temperatures. Air-temperature-based UHIs (UHIA), calculated using the Global Historical Climatology Network (GHCN) daily air temperatures, are compared with UHIS for urban areas in different biomes during different seasons. NLCD ISA is used to define urban and rural temperatures and to stratify the sampling for LST and air temperatures. We find that the MODIS LST agrees well with observed air temperature during the nighttime, but tends to overestimate it during the daytime, especially during summer and in nonforested areas. The minimum air temperature analyses show that UHIs in forests have an average UHIA of 1 C during the summer. The UHIS, calculated from nighttime LST, has similar magnitude of 1-2 C. By contrast, the LSTs show a midday summer UHIS of 3-4 C for cities in forests, whereas the average summer UHIA calculated from maximum air temperature is close to 0 C. In addition, the LSTs and air temperatures difference between 2006 and 2011 are in agreement, albeit with different magnitude.

  6. Retrieval of air temperatures from crowd-sourced battery temperatures of cell phones

    NASA Astrophysics Data System (ADS)

    Overeem, Aart; Robinson, James; Leijnse, Hidde; Uijlenhoet, Remko; Steeneveld, Gert-Jan; Horn, Berthold K. P.

    2013-04-01

    Accurate air temperature observations are important for urban meteorology, for example to study the urban heat island and adverse effects of high temperatures on human health. The number of available temperature observations is often relatively limited. A new development is presented to derive temperature information for the urban canopy from an alternative source: cell phones. Battery temperature data were collected by users of an Android application for cell phones (opensignal.com). The application automatically sends battery temperature data to a server for storage. In this study, battery temperatures are averaged in space and time to obtain daily averaged battery temperatures for each city separately. A regression model, which can be related to a physical model, is employed to retrieve daily air temperatures from battery temperatures. The model is calibrated with observed air temperatures from a meteorological station of an airport located in or near the city. Time series of air temperatures are obtained for each city for a period of several months, where 50% of the data is for independent verification. Results are presented for Buenos Aires, London, Los Angeles, Paris, Mexico City, Moscow, Rome, and Sao Paulo. The evolution of the retrieved air temperatures often correspond well with the observed ones. The mean absolute error of daily air temperatures is less than 2 degrees Celsius, and the bias is within 1 degree Celsius. This shows that monitoring air temperatures employing an Android application holds great promise. Since 75% of the world's population has a cell phone, 20% of the land surface of the earth has cellular telephone coverage, and 500 million devices use the Android operating system, there is a huge potential for measuring air temperatures employing cell phones. This could eventually lead to real-time world-wide temperature maps.

  7. Mesoscale climatic simulation of surface air temperature cooling by highly reflective greenhouses in SE Spain.

    PubMed

    Campra, Pablo; Millstein, Dev

    2013-01-01

    A long-term local cooling trend in surface air temperature has been monitored at the largest concentration of reflective greenhouses in the world, at the Province of Almeria, SE Spain, associated with a dramatic increase in surface albedo in the area. The availability of reliable long-term climatic field data at this site offers a unique opportunity to test the skill of mesoscale meteorological models describing and predicting the impacts of land use change on local climate. Using the Weather Research and Forecast (WRF) mesoscale model, we have run a sensitivity experiment to simulate the impact of the observed surface albedo change on monthly and annual surface air temperatures. The model output showed a mean annual cooling of 0.25 °C associated with a 0.09 albedo increase, and a reduction of 22.8 W m(-2) of net incoming solar radiation at surface. Mean reduction of summer daily maximum temperatures was 0.49 °C, with the largest single-day decrease equal to 1.3 °C. WRF output was evaluated and compared with observations. A mean annual warm bias (MBE) of 0.42 °C was estimated. High correlation coefficients (R(2) > 0.9) were found between modeled and observed values. This study has particular interest in the assessment of the potential for urban temperature cooling by cool roofs deployment projects, as well as in the evaluation of mesoscale climatic models performance. PMID:24074145

  8. Associations of endothelial function and air temperature in diabetic subjects

    EPA Science Inventory

    Background and Objective: Epidemiological studies consistently show that air temperature is associated with changes in cardiovascular morbidity and mortality. However, the biological mechanisms underlying the association remain largely unknown. As one index of endothelial functio...

  9. High Lapse Rates in AIRS Retrieved Temperatures in Cold Air Outbreaks

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Kahn, Brian; Olsen, Edward T.; Fishbein, Evan

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) experiment, on NASA's Aqua spacecraft, uses a combination of infrared and microwave observations to retrieve cloud and surface properties, plus temperature and water vapor profiles comparable to radiosondes throughout the troposphere, for cloud cover up to 70%. The high spectral resolution of AIRS provides sensitivity to important information about the near-surface atmosphere and underlying surface. A preliminary analysis of AIRS temperature retrievals taken during January 2003 reveals extensive areas of superadiabatic lapse rates in the lowest kilometer of the atmosphere. These areas are found predominantly east of North America over the Gulf Stream, and, off East Asia over the Kuroshio Current. Accompanying the high lapse rates are low air temperatures, large sea-air temperature differences, and low relative humidities. Imagery from a Visible / Near Infrared instrument on the AIRS experiment shows accompanying clouds. These lines of evidence all point to shallow convection in the bottom layer of a cold air mass overlying warm water, with overturning driven by heat flow from ocean to atmosphere. An examination of operational radiosondes at six coastal stations in Japan shows AIRS to be oversensitive to lower tropospheric lapse rates due to systematically warm near-surface air temperatures. The bias in near-surface air temperature is seen to be independent of sea surface temperature, however. AIRS is therefore sensitive to air-sea temperature difference, but with a warm atmospheric bias. A regression fit to radiosondes is used to correct AIRS near-surface retrieved temperatures, and thereby obtain an estimate of the true atmosphere-ocean thermal contrast in five subtropical regions across the north Pacific. Moving eastward, we show a systematic shift in this air-sea temperature differences toward more isothermal conditions. These results, while preliminary, have implications for our understanding of heat flow from ocean to

  10. 40 CFR 60.5215 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution control device used to comply with the emission limits, according to § 60.5220(c), no later than 12 months following the previous annual air pollution control...

  11. 40 CFR 60.5215 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution control device used to comply with the emission limits, according to § 60.5220(c), no later than 12 months following the previous annual air pollution control...

  12. 40 CFR 60.5215 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution control device used to comply with the emission limits, according to § 60.5220(c), no later than 12 months following the previous annual air pollution control...

  13. 40 CFR 60.5215 - By what date must I conduct annual air pollution control device inspections and make any...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air pollution control device inspections and make any necessary repairs? (a) You must conduct an annual inspection of each air pollution control device used to comply with the emission limits, according to § 60.5220(c), no later than 12 months following the previous annual air pollution control...

  14. Lessons Learned from AIRS: Improved Determination of Surface and Atmospheric Temperatures Using Only Shortwave AIRS Channels

    NASA Technical Reports Server (NTRS)

    Susskind, Joel

    2011-01-01

    This slide presentation reviews the use of shortwave channels available to the Atmospheric Infrared Sounder (AIRS) to improve the determination of surface and atmospheric temperatures. The AIRS instrument is compared with the Infrared Atmospheric Sounding Interferometer (IASI) on-board the MetOp-A satellite. The objectives of the AIRS/AMSU were to (1) provide real time observations to improve numerical weather prediction via data assimilation, (2) Provide observations to measure and explain interannual variability and trends and (3) Use of AIRS product error estimates allows for QC optimized for each application. Successive versions in the AIRS retrieval methodology have shown significant improvement.

  15. Effect of Initial Mixture Temperature on Flame Speed of Methane-Air, Propane-Air, and Ethylene-Air Mixtures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L

    1952-01-01

    Flame speeds based on the outer edge of the shadow cast by the laminar Bunsen cone were determined as functions of composition for methane-air mixtures at initial mixture temperatures ranging from -132 degrees to 342 degrees c and for propane-air and ethylene-air mixtures at initial mixture temperatures ranging from -73 degrees to 344 degrees c. The data showed that maximum flame speed increased with temperature at an increasing rate. The percentage change in flame speed with change in initial temperature for the three fuels followed the decreasing order, methane, propane, and ethylene. Empirical equations were determined for maximum flame speed as a function of initial temperature over the temperature range covered for each fuel. The observed effect of temperature on flame speed for each of the fuels was reasonably well predicted by either the thermal theory as presented by Semenov or the square-root law of Tanford and Pease.

  16. Air temperature field distribution estimations over a Chinese mega-city using MODIS land surface temperature data: the case of Shanghai

    NASA Astrophysics Data System (ADS)

    Ma, Weichun; Zhou, Liguo; Zhang, Hao; Zhang, Yan; Dai, Xiaoyan

    2016-03-01

    The capability of obtaining spatially distributed air temperature data from remote sensing measurements is an improvement for many environmental applications focused on urban heat island, carbon emissions, climate change, etc. This paper is based on the MODIS/Terra and Aqua data utilized to study the effect of the urban atmospheric heat island in Shanghai, China. The correlation between retrieved MODIS land surface temperature (LST) and air temperature measured at local weather stations was initially studied at different temporal and spatial scales. Secondly, the air temperature data with spatial resolutions of 250 m and 1 km were estimated from MODIS LST data and in-situ measured air temperature. The results showed that there is a slightly higher correlation between air temperature and MODIS LST at a 250m resolution in spring and autumn on an annual scale than observed at a 1 km resolution. Although the distribution pattern of the air temperature thermal field varies in different seasons, the urban heat island (UHI) in Shanghai is characterized by a distribution pattern of multiple centers, with the central urban area as the primary center and the built-up regions in each district as the subcenters. This study demonstrates the potential not only for estimating the distribution of the air temperature thermal field from MODIS LST with 250 m resolution in spring and autumn in Shanghai, but also for providing scientific and effective methods for monitoring and studying UHI effect in a Chinese mega-city such as Shanghai.

  17. A physically based analytical spatial air temperature and humidity model

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Endreny, Theodore A.; Nowak, David J.

    2013-09-01

    Spatial variation of urban surface air temperature and humidity influences human thermal comfort, the settling rate of atmospheric pollutants, and plant physiology and growth. Given the lack of observations, we developed a Physically based Analytical Spatial Air Temperature and Humidity (PASATH) model. The PASATH model calculates spatial solar radiation and heat storage based on semiempirical functions and generates spatially distributed estimates based on inputs of topography, land cover, and the weather data measured at a reference site. The model assumes that for all grids under the same mesoscale climate, grid air temperature and humidity are modified by local variation in absorbed solar radiation and the partitioning of sensible and latent heat. The model uses a reference grid site for time series meteorological data and the air temperature and humidity of any other grid can be obtained by solving the heat flux network equations. PASATH was coupled with the USDA iTree-Hydro water balance model to obtain evapotranspiration terms and run from 20 to 29 August 2010 at a 360 m by 360 m grid scale and hourly time step across a 285 km2 watershed including the urban area of Syracuse, NY. PASATH predictions were tested at nine urban weather stations representing variability in urban topography and land cover. The PASATH model predictive efficiency R2 ranged from 0.81 to 0.99 for air temperature and 0.77 to 0.97 for dew point temperature. PASATH is expected to have broad applications on environmental and ecological models.

  18. Long-term air temperature variation in the Karkonosze mountains according to atmospheric circulation

    NASA Astrophysics Data System (ADS)

    Migała, Krzysztof; Urban, Grzegorz; Tomczyński, Karol

    2016-07-01

    The results of meteorological measurements carried out continuously on Mt Śnieżka in Karkonosze mountains since 1880 well document the warming observed on a global scale. Data analysis indicates warming expressed by an increase in the mean annual air temperature of 0.8 °C/100 years. A much higher temperature increase was recorded in the last two decades at the turn of the twenty-first century. Mean decade air temperatures increased from -0.1 to 1.5 °C. It has been shown that there are relationships between air temperature at Mt Śnieżka and global mechanisms of atmospheric and oceanic circulation. Thermal conditions of the Karkonosze (Mt Śnieżka) accurately reflect global climate trends and impact of the North Atlantic Oscillation (NAO) index, macrotypes of atmospheric circulation in Europe (GWL) and Atlantic Multidecadal Oscillation (AMO). The increase in air temperature during the 1989-2012 solar magnetic cycle may reveal a synergy effect to which astrophysical effects and atmospheric and oceanic circulation effects contribute, modified by constantly increasing anthropogenic factors.

  19. Air Temperature Evolution for the Last 10 Years in the National Petroleum Reserve Alaska

    NASA Astrophysics Data System (ADS)

    Vas, D. A.; Toniolo, H. A.; Kemnitz, R.; Bailey, J. P.

    2014-12-01

    The National Petroleum Reserve-Alaska (NPR-A), an area of approximately 23 million acres, extends from the north side of the Brooks Range to the Arctic Ocean. The Bureau of Land Management (BLM), as a part of studies focused on establishing baseline conditions for weather and hydrological parameters, installed six weather and gauging stations along the NPR-A. This work concentrates on weather conditions, specifically air temperature. Data collected in each of these sites include air temperature (in all the stations), while summer precipitation and wind parameters were collected only at three stations. We present an initial summary of air temperature evolution in the stations, from the installation of each site to September 30, 2013. Available information indicates that the entire region followed a pronounced warming trend, finishing with the 2010/2011 winter, which was the warmest winter recorded in each station. A nearly 20 percent increase in annual cumulative freezing degree days (ACFDD) occurred between the 2011/2012 and 2012/2013 winters. A preliminary analysis of air temperature on a monthly basis shows that, in general, the months of January and March of 2012 contributed the most to the increase in the ACFDD. In particular, the mean monthly temperature in March was in the vicinity of -35 °C in all the stations, which certainly marked 2012 as the coldest March on record.

  20. Equipment for Measuring Air Flow, Air Temperature, Relative Humidity, and Carbon Dioxide in Schools. Technical Bulletin.

    ERIC Educational Resources Information Center

    Jacobs, Bruce W.

    Information on equipment and techniques that school facility personnel may use to evaluate IAQ conditions are discussed. Focus is placed on the IAQ parameters of air flow, air temperature, relative humidity, as well as carbon dioxide and the equipment used to measure these factors. Reasons for measurement and for when the measurement of these…

  1. Improving Forecast Skill by Assimilation of AIRS Temperature Soundings

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Reale, Oreste

    2010-01-01

    AIRS was launched on EOS Aqua on May 4, 2002, together with AMSU-A and HSB, to form a next generation polar orbiting infrared and microwave atmospheric sounding system. The primary products of AIRS/AMSU-A are twice daily global fields of atmospheric temperature-humidity profiles, ozone profiles, sea/land surface skin temperature, and cloud related parameters including OLR. The AIRS Version 5 retrieval algorithm, is now being used operationally at the Goddard DISC in the routine generation of geophysical parameters derived from AIRS/AMSU data. A major innovation in Version 5 is the ability to generate case-by-case level-by-level error estimates delta T(p) for retrieved quantities and the use of these error estimates for Quality Control. We conducted a number of data assimilation experiments using the NASA GEOS-5 Data Assimilation System as a step toward finding an optimum balance of spatial coverage and sounding accuracy with regard to improving forecast skill. The model was run at a horizontal resolution of 0.5 deg. latitude X 0.67 deg longitude with 72 vertical levels. These experiments were run during four different seasons, each using a different year. The AIRS temperature profiles were presented to the GEOS-5 analysis as rawinsonde profiles, and the profile error estimates delta (p) were used as the uncertainty for each measurement in the data assimilation process. We compared forecasts analyses generated from the analyses done by assimilation of AIRS temperature profiles with three different sets of thresholds; Standard, Medium, and Tight. Assimilation of Quality Controlled AIRS temperature profiles significantly improve 5-7 day forecast skill compared to that obtained without the benefit of AIRS data in all of the cases studied. In addition, assimilation of Quality Controlled AIRS temperature soundings performs better than assimilation of AIRS observed radiances. Based on the experiments shown, Tight Quality Control of AIRS temperature profile performs best

  2. Radionuclide air emissions annual report for calendar year 1994

    SciTech Connect

    Not Available

    1995-04-04

    This report presents the results of the Pinellas Plant air sampling program for the year of 1994. Topics discussed include: site description; source description; air emissions data; dose assessments; description of dose model; summary of input parameters of dose model; unplanned releases; and diffuse emissions. Included in the attachments of this document are: non-radon individual dose assessment; non-radon population dose assessment; summary of stack flow rate measurements; HOTSPOT computer model run; and meteorological data for the Pinellas Plant for 1994.

  3. The Veriability of Radiative Balance Elements and Air Temperature on the Asian Region of Russia

    NASA Astrophysics Data System (ADS)

    Kharyutkina, E. V.; Ippolitov, I. I.; Loginov, S. V.

    2011-01-01

    The variability of spatial-temporal distribution of temperature and radiative and heat balances components is investigated for the Asian territory of Russia (45 - 80oN, 60-180oE) using JRA-25 reanalysis data for the period of current global warming 1979-2008 It is shown that since the beginning of 90th of XX century the increase of back earth-atmosphere short-wave radiation is observed. Such tendency is in conformity with the cloud cover dynamics and downward short-wave radiation at the surface. Annual averaged radiative balance values at the top are negative; it is consistent with negative annual averaged air temperature, averaged over territory. The downward trend of radiative balance is the most obvious after the beginning of 90th of XX century.

  4. Propagation Of Error And The Reliability Of Global Air Temperature Projections

    NASA Astrophysics Data System (ADS)

    Frank, P.

    2013-12-01

    General circulation model (GCM) projections of the impact of rising greenhouse gases (GHGs) on globally averaged annual surface air temperatures are a simple linear extrapolation of GHG forcing, as indicated by their accurate simulation using the equation, ΔT = a×33K×[(F0+∑iΔFi)/F0], where F0 is the total GHG forcing of projection year zero, ΔFi is the increment of GHG forcing in the ith year, and a is a variable dimensionless fraction that follows GCM climate sensitivity. Linearity of GCM air temperature projections means that uncertainty propagates step-wise as the root-sum-square of error. The annual average error in total cloud fraction (TCF) resulting from CMIP5 model theory-bias is ×12%, equivalent to ×5 Wm-2 uncertainty in the energy state of the projected atmosphere. Propagated uncertainty due to TCF error is always much larger than the projected globally averaged air temperature anomaly, and reaches ×20 C in a centennial projection. CMIP5 GCMs thus have no predictive value.

  5. Trend analysis of air temperature and precipitation time series over Greece: 1955-2010

    NASA Astrophysics Data System (ADS)

    Marougianni, G.; Melas, D.; Kioutsioukis, I.; Feidas, H.; Zanis, P.; Anandranistakis, E.

    2012-04-01

    In this study, a database of air temperature and precipitation time series from the network of Hellenic National Meteorological Service has been developed in the framework of the project GEOCLIMA, co-financed by the European Union and Greek national funds through the Operational Program "Competitiveness and Entrepreneurship" of the Research Funding Program COOPERATION 2009. Initially, a quality test was applied to the raw data and then missing observations have been imputed with a regularized, spatial-temporal expectation - maximization algorithm to complete the climatic record. Next, a quantile - matching algorithm was applied in order to verify the homogeneity of the data. The processed time series were used for the calculation of temporal annual and seasonal trends of air temperature and precipitation. Monthly maximum and minimum surface air temperature and precipitation means at all available stations in Greece were analyzed for temporal trends and spatial variation patterns for the longest common time period of homogenous data (1955 - 2010), applying the Mann-Kendall test. The majority of the examined stations showed a significant increase in the summer maximum and minimum temperatures; this could be possibly physically linked to the Etesian winds, because of the less frequent expansion of the low over the southeastern Mediterranean. Summer minimum temperatures have been increasing at a faster rate than that of summer maximum temperatures, reflecting an asymmetric change of extreme temperature distributions. Total annual precipitation has been significantly decreased at the stations located in western Greece, as well as in the southeast, while the remaining areas exhibit a non-significant negative trend. This reduction is very likely linked to the positive phase of the NAO that resulted in an increase in the frequency and persistence of anticyclones over the Mediterranean.

  6. Evaluation of Annual Performance of Multi-type Air-conditioners for Buildings

    NASA Astrophysics Data System (ADS)

    Watanabe, Choyu; Ohashi, Ei-Ichiro; Hirota, Masafumi; Nagamatsu, Katsuaki; Nakayama, Hiroshi

    The partial thermal load performance tests of electric-motor driven multi-type air-conditioners for buildings, the rated cooling and heating capacities of which were 56 kW and 63 kW, respectively, were carried out using the air-enthalpy method testing apparatus. Based on the results of those tests, the applicability of JIS B 8616: 2006, which was developed for the estimation of the annual electricity consumption of packaged air-conditioners with rated cooling capacities less than 28 kW, to the multi-type air-conditioners with larger capacities were examined. It was found that JIS B 8616: 2006 generally overestimates COP under a relatively low thermal load operation. As a result, the annual electricity consumption is underestimated by JIS. The prediction error changes depending of the building uses, and it amounted to -17 % in the case of office and -6 % in the detached shop.

  7. [Effect of air temperature and rainfall on wetland ecosystem CO2 exchange in China].

    PubMed

    Chu, Xiao-jing; Han, Guang-xuan

    2015-10-01

    Wetland can be a potential efficient sink to reduce global warming due to its higher primary productivity and lower carbon decomposition rate. While there has been a series progress on the influence mechanism of ecosystem CO2 exchange over China' s wetlands, a systematic metaanalysis of data still needs to be improved. We compiled data of ecosystem CO2 exchange of 21 typical wetland vegetation types in China from 29 papers and carried out an integrated analysis of air temperature and precipitation effects on net ecosystem CO2 exchange (NEE), ecosystem respiration (Reco), gross primary productivity (GPP), the response of NEE to PAR, and the response of Reco to temperature. The results showed that there were significant responses (P<0.05) of NEE (R2 = 50%, R2=57%), GPP (R2 = 60%, R2 = 50%) Reco (R2 = 44%, R2=50%) with increasing air temperature and enhanced precipitation on the annual scale. On the growing season scale, air temperature accounted for 50% of the spatial variation of NEE, 36% of GPP and 19% of Reco, respectively. Both NEE (R2 = 33%) and GPP (R2 =25%) were correlated positively with precipitation (P<0.05). However, the relationship between Reco and precipitation was not significant (P>0.05). Across different Chinese wetlands, both precipitation and temperature had no significant effect on apparent quantum yield (α) or ecosystem respiration in the daytime (Reco,day, P>0.05). The maximum photosynthesis rate (Amax) was remarkably correlated with precipitation (P <0.01), but not with air temperature. Besides, there was no significant correlation between basal respiration (Rref) and precipitation (P>0.05). Precipitation was negatively correlated with temperature sensitivity of Reco (Q10, P<0.05). Furthermore, temperature accounted for 35% and 46% of the variations in temperature sensitivity of Reco (Q10) and basal respiration (Rref P<0.05), respectively. PMID:26995905

  8. Heat tolerance of higher plants cenosis to damaging air temperatures

    NASA Astrophysics Data System (ADS)

    Ushakova, Sofya; Shklavtsova, Ekaterina

    Designing sustained biological-technical life support systems (BTLSS) including higher plants as a part of a photosynthesizing unit, it is important to foresee the multi species cenosis reaction on either stress-factors. Air temperature changing in BTLSS (because of failure of a thermoregulation system) up to the values leading to irreversible damages of photosynthetic processes is one of those factors. However, it is possible to increase, within the certain limits, the plant cenosis tolerance to the unfavorable temperatures’ effect due to the choice of the higher plants possessing resistance both to elevated and to lowered air temperatures. Besides, the plants heat tolerance can be increased when subjecting them during their growing to the hardening off temperatures’ effect. Thus, we have come to the conclusion that it is possible to increase heat tolerance of multi species cenosis under the damaging effect of air temperature of 45 (°) СC.

  9. Innovative coal gasification system with high temperature air

    SciTech Connect

    Yoshikawa, K.; Katsushima, H.; Kasahara, M.; Hasegawa, T.; Tanaka, R.; Ootsuka, T.

    1997-12-31

    This paper proposes innovative coal gasification power generation systems where coal is gasified with high temperature air of about 1300K produced by gasified coal fuel gas. The main features of these systems are high thermal efficiency, low NO{sub x} emission, compact desulfurization and dust removal equipment and high efficiency molten slag removal with a very compact gasifier. Recent experimental results on the pebble bed coal gasifier appropriate for high temperature air coal gasification are reported, where 97.7% of coal ash is successfully caught in the pebble bed and extracted without clogging. A new concept of high temperature air preheating system is proposed which is characterized by its high reliability and low cost.

  10. Compressed air energy storage technology program. Annual report for 1979

    SciTech Connect

    Loscutoff, W.V.

    1980-06-01

    The objectives of the Compressed Air Energy Storage (CAES) program are to establish stability criteria for large underground reservoirs in salt domes, hard rock, and porous rock used for air storage in utility applications, and to develop second-generation CAES technologies that have minimal or no dependence on petroleum fuels. During the year reported reports have been issued on field studies on CAES on aquifers and in salt, stability, and design criteria for CAES and for pumped hydro-storage caverns, laboratory studies of CAES in porous rock reservoris have continued. Research has continued on combined CAES/Thermal Energy Storage, CAES/Solar systems, coal-fired fluidized bed combustors for CAES, and two-reservoir advanced CAES concepts. (LCL)

  11. The role of subsurface soil temperature feedbacks in summer surface air temperature variability over East Asia

    NASA Astrophysics Data System (ADS)

    Zhang, J.

    2012-12-01

    Soil temperature, an important component of land surface, can influence the climate through its effects on surface energy and water budgets and resulted changes in regional atmospheric circulation. However, the effects of soil temperature on climate variations have been less discussed. This study investigates the role of subsurface soil temperature feedbacks in influencing summer surface air temperature variability over East Asia by means of regional climate model (RCM) simulations. For this aim, two long-term simulations with and without subsurface soil temperature feedbacks are performed with the Weather Research and Forecasting (WRF) model. From our investigation, it is evident that subsurface soil temperature feedbacks make a dominant contribution to amplifying summer surface air temperature variability over the arid/semi-arid regions. Further analysis reveals that subsurface soil temperature exhibits an asymmetric effect on summer daytime and nighttime surface air temperature variability, with a stronger effect on daily minimum temperature variability than that of daily maximum temperature variability. This study provides the first RCM-based demonstration that subsurface soil temperature feedbacks play an important role in influencing climate variability over East Asia, such as summer surface air temperature. In the meanwhile, the model bias should be recognized. The results achieved by this study thus need to be further confirmed in a multi-model framework to eliminate the model dependence.

  12. Passive radiative cooling below ambient air temperature under direct sunlight.

    PubMed

    Raman, Aaswath P; Anoma, Marc Abou; Zhu, Linxiao; Rephaeli, Eden; Fan, Shanhui

    2014-11-27

    Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day. PMID:25428501

  13. 40 CFR 60.2716 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... air pollution control device inspection? 60.2716 Section 60.2716 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY... annual air pollution control device inspection), you must complete the air pollution control...

  14. 40 CFR 60.2716 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... air pollution control device inspection? 60.2716 Section 60.2716 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY... annual air pollution control device inspection), you must complete the air pollution control...

  15. 40 CFR 60.2716 - By what date must I conduct the annual air pollution control device inspection?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... air pollution control device inspection? 60.2716 Section 60.2716 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY... annual air pollution control device inspection), you must complete the air pollution control...

  16. Emission Controls Using Different Temperatures of Combustion Air

    PubMed Central

    Holubčík, Michal; Papučík, Štefan

    2014-01-01

    The effort of many manufacturers of heat sources is to achieve the maximum efficiency of energy transformation chemically bound in the fuel to heat. Therefore, it is necessary to streamline the combustion process and minimize the formation of emission during combustion. The paper presents an analysis of the combustion air temperature to the heat performance and emission parameters of burning biomass. In the second part of the paper the impact of different dendromass on formation of emissions in small heat source is evaluated. The measured results show that the regulation of the temperature of the combustion air has an effect on concentration of emissions from the combustion of biomass. PMID:24971376

  17. Variability of Winter Air Temperature in Mid-Latitude Europe

    NASA Technical Reports Server (NTRS)

    Otterman, J.; Ardizzone, J.; Atlas, R.; Bungato, D.; Cierniewski, J.; Jusem, J. C.; Przybylak, R.; Schubert, S.; Starr, D.; Walczewski, J.

    2002-01-01

    The aim of this paper is to report extreme winter/early-spring air temperature (hereinafter temperature) anomalies in mid-latitude Europe, and to discuss the underlying forcing to these interannual fluctuations. Warm advection from the North Atlantic in late winter controls the surface-air temperature, as indicated by the substantial correlation between the speed of the surface southwesterlies over the eastern North Atlantic (quantified by a specific Index Ina) and the 2-meter level air temperatures (hereinafter Ts) over Europe, 45-60 deg N, in winter. In mid-March and subsequently, the correlation drops drastically (quite often it is negative). This change in the relationship between Ts and Ina marks a transition in the control of the surface-air temperature: absorption of insolation replaces the warm advection as the dominant control. This forcing by maritime-air advection in winter was demonstrated in a previous publication, and is re-examined here in conjunction with extreme fluctuations of temperatures in Europe. We analyze here the interannual variability at its extreme by comparing warm-winter/early-spring of 1989/90 with the opposite scenario in 1995/96. For these two December-to-March periods the differences in the monthly mean temperature in Warsaw and Torun, Poland, range above 10 C. Short-term (shorter than a month) fluctuations of the temperature are likewise very strong. We conduct pentad-by-pentad analysis of the surface-maximum air temperature (hereinafter Tmax), in a selected location, examining the dependence on Ina. The increased cloudiness and higher amounts of total precipitable water, corollary effects to the warm low-level advection. in the 1989/90 winter, enhance the positive temperature anomalies. The analysis of the ocean surface winds is based on the Special Sensor Microwave/Imager (SSM/I) dataset; ascent rates, and over land wind data are from the European Centre for Medium-Range Weather Forecasts (ECMWF); maps of 2-m temperature, cloud

  18. Increasing influence of air temperature on upper Colorado River streamflow

    NASA Astrophysics Data System (ADS)

    Woodhouse, Connie A.; Pederson, Gregory T.; Morino, Kiyomi; McAfee, Stephanie A.; McCabe, Gregory J.

    2016-03-01

    This empirical study examines the influence of precipitation, temperature, and antecedent soil moisture on upper Colorado River basin (UCRB) water year streamflow over the past century. While cool season precipitation explains most of the variability in annual flows, temperature appears to be highly influential under certain conditions, with the role of antecedent fall soil moisture less clear. In both wet and dry years, when flow is substantially different than expected given precipitation, these factors can modulate the dominant precipitation influence on streamflow. Different combinations of temperature, precipitation, and soil moisture can result in flow deficits of similar magnitude, but recent droughts have been amplified by warmer temperatures that exacerbate the effects of relatively modest precipitation deficits. Since 1988, a marked increase in the frequency of warm years with lower flows than expected, given precipitation, suggests continued warming temperatures will be an increasingly important influence in reducing future UCRB water supplies.

  19. Increasing influence of air temperature on upper Colorado River streamflow

    USGS Publications Warehouse

    Woodhouse, Connie A.; Pederson, Gregory T.; Morino, Kiyomi; McAfee, Stephanie A.; McCabe, Gregory

    2016-01-01

    This empirical study examines the influence of precipitation, temperature, and antecedent soil moisture on upper Colorado River basin (UCRB) water year streamflow over the past century. While cool season precipitation explains most of the variability in annual flows, temperature appears to be highly influential under certain conditions, with the role of antecedent fall soil moisture less clear. In both wet and dry years, when flow is substantially different than expected given precipitation, these factors can modulate the dominant precipitation influence on streamflow. Different combinations of temperature, precipitation, and soil moisture can result in flow deficits of similar magnitude, but recent droughts have been amplified by warmer temperatures that exacerbate the effects of relatively modest precipitation deficits. Since 1988, a marked increase in the frequency of warm years with lower flows than expected, given precipitation, suggests continued warming temperatures will be an increasingly important influence in reducing future UCRB water supplies.

  20. The Eighth Annual Air Pollution Medical Research Conference, Los Angeles, March 2-4, 1966.

    ERIC Educational Resources Information Center

    Archives of Environmental Health, 1967

    1967-01-01

    Papers read before the Eighth Annual American Medical Association Air Pollution Medical Research Conference, Los Angeles, California, March 2-4, 1966, are presented in this document. Topics deal with basic approaches to the study of the effects of inhaled irritants on the lung; environmental parameters in relation to host responses; biological…

  1. 77 FR 24440 - Approval and Promulgation of Air Quality Implementation Plans; North Carolina; Annual Emissions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-24

    ... ozone national ambient air quality standard (NAAQS). See 73 FR 16436. The current action, however, is...; Annual Emissions Reporting AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY... meet the emissions statements requirement for North Carolina. EPA is proposing to approve the...

  2. Pulsed positive streamer discharges in air at high temperatures

    NASA Astrophysics Data System (ADS)

    Ono, Ryo; Kamakura, Taku

    2016-08-01

    Atmospheric-pressure air pulsed positive streamer discharges are generated in a 13 mm point-plane gap in the temperature range of 293 K–1136 K, and the effect of temperature on the streamer discharges is studied. When the temperature is increased, the product of applied voltage and temperature VT proportional to the reduced electric field can be used as a primary parameter that determines some discharge parameters regardless of temperature. For a given VT, the transferred charge per pulse, streamer diameter, product of discharge energy and temperature, and length of secondary streamer are almost constant regardless of T, whereas the streamer velocity decreases with increasing T and the decay rate of the discharge current is proportional to 1/T. The N2(C) emission intensity is approximately determined by the discharge energy independent of T. These results are useful to predict the streamer discharge and its reactive species production when the ambient temperature is increased.

  3. Effects of air flow directions on composting process temperature profile

    SciTech Connect

    Kulcu, Recep; Yaldiz, Osman

    2008-07-01

    In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO{sub 2} and O{sub 2} ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2.

  4. Temperature gradients and clear-air turbulence probabilities

    NASA Technical Reports Server (NTRS)

    Bender, M. A.; Panofsky, H. A.; Peslen, C. A.

    1976-01-01

    In order to forecast clear-air turbulence (CAT) in jet aircraft flights, a study was conducted in which the data from a special-purpose instrument aboard a Boeing 747 jet airliner were compared with satellite-derived radiance gradients, conventional temperature gradients from analyzed maps, and temperature gradients obtained from a total air temperature sensor on the plane. The advantage of making use of satellite-derived data is that they are available worldwide without the need for radiosonde observations, which are scarce in many parts of the world. Major conclusions are that CAT probabilities are significantly higher over mountains than flat terrain, and that satellite radiance gradients appear to discriminate between CAT and no CAT better than conventional temperature gradients over flat lands, whereas the reverse is true over mountains, the differences between the two techniques being not large over mountains.

  5. Annual air pollution caused by the Hungry Ghost Festival.

    PubMed

    Khezri, B; Chan, Y Y; Tiong, L Y D; Webster, R D

    2015-09-01

    Burning of joss paper and incense is still a very common traditional custom in countries with a majority Chinese population. The Hungry Ghost Festival which is celebrated in the 7 month of the Chinese calendar is one of the events where joss paper and incense are burned as offerings. This study investigates the impact of the Ghost Month Festival (open burning event) on air quality by analysis of the chemical composition of particulate matter (PM) and rainwater samples collected during this event, compared with data collected throughout the year, as well as bottom ash samples from burning the original joss paper and incense. The results showed that the change in the chemical composition of the rainwater and PM2.5 (PM ≤ 2.5 μm) atmospheric samples could be correlated directly with burning events during this festival, with many elements increasing between 18% and 60% during August and September compared to the yearly mean concentrations. The order of percentage increase in elemental composition (in rain water and PM2.5) during the Hungry Ghost Festival is as follows: Zn > Ca > K > Mg > Fe > Al > Na ∼ Mn ∼ Ti ∼ V > Cu > As > Ni > Co > Cd > Cr > Pb. The chemical composition of the original source materials (joss paper and incense for combustion) and their associated bottom ash were analysed to explain the impact of burning on air quality. PMID:26220212

  6. The Effects of Air Pollution and Temperature on COPD.

    PubMed

    Hansel, Nadia N; McCormack, Meredith C; Kim, Victor

    2016-06-01

    Chronic Obstructive Pulmonary Disease (COPD) affects 12-16 million people in the United States and is the third-leading cause of death. In developed countries, smoking is the greatest risk factor for the development of COPD, but other exposures also contribute to the development and progression of the disease. Several studies suggest, though are not definitive, that outdoor air pollution exposure is linked to the prevalence and incidence of COPD. Among individuals with COPD, outdoor air pollutants are associated with loss of lung function and increased respiratory symptoms. In addition, outdoor air pollutants are also associated with COPD exacerbations and mortality. There is much less evidence for the impact of indoor air on COPD, especially in developed countries in residences without biomass exposure. The limited existing data suggests that indoor particulate matter and nitrogen dioxide concentrations are linked to increased respiratory symptoms among patients with COPD. In addition, with the projected increases in temperature and extreme weather events in the context of climate change there has been increased attention to the effects of heat exposure. Extremes of temperature-both heat and cold-have been associated with increased respiratory morbidity in COPD. Some studies also suggest that temperature may modify the effect of pollution exposure and though results are not conclusive, understanding factors that may modify susceptibility to air pollution in patients with COPD is of utmost importance. PMID:26683097

  7. Experimental and theoretical analysis results for high temperature air combustion

    SciTech Connect

    Tanigawa, Tadashi; Morita, Mitsunobu

    1998-07-01

    With Japan's preparation of its Action program to prevent global warming in 1990 and the holding of the United National Conference on Environment and Development (the Earth Summit) in 1992 as a backdrop, reflecting the global effort to protect the environment, a high performance industrial furnace development project was launched in 1993 by the New Energy and Industrial Technology Development Organization (NEDO). This project focuses on the development of a combustion technology which uses air that is preheated to extremely high temperatures (above 1,000 C), heretofore considered impossible. Not only can this technology reduce carbon dioxide emission, thought to cause the greenhouse effect, by over 30%, but it can also reduce nitrogen oxide emission by nearly half. This new technology makes use of the recently-developed high-cycle regenerative heat exchanger, for preheating the furnace air supply. This exchanger preheats air to above 1,000 C, much higher than for conventional furnaces, and then this air is injected with fuel. R and D data have shown that CO{sub 2} and NO{sub x} emissions can be reduced markedly. However, the theoretical analysis is yet to be made, thereby hampering efforts to have this advanced technology become widely adopted. This project accumulated new data related to uniform temperature distribution, high energy heat transfer and low NO{sub x} as common characteristics of high temperature air combustion.

  8. Flame Speeds of Methane-Air, Propane-Air, and Ethylene-Air Mixtures at Low Initial Temperatures

    NASA Technical Reports Server (NTRS)

    Dugger, Gordon L; Heimel, Sheldon

    1952-01-01

    Flame speeds were determined for methane-air, propane-air, and ethylene-air mixtures at -73 C and for methane-air mixtures at -132 C. The data extend the curves of maximum flame speed against initial mixture temperature previously established for the range from room temperature to 344 C. Empirical equations for maximum flame speed u(cm/ sec) as a function of initial mixture temperature T(sub O) were determined to be as follows: for methane, for T(sub O) from 141 to 615 K, u = 8 + 0.000160 T(sub O)(exp 2.11); for propane, for T(sub O) from 200 to 616 K, u = 10 + 0.000342 T(sub O)(exp 2.00); for ethylene, for T(sub O) from 200 to 617 K, u = 10 + 0.00259 T(sub O)(exp 1.74). Relative flame speeds at low initial temperatures were predicted within approximately 20 percent by either the thermal theory as presented by Semenov or by the diffusion theory of Tanford and Pease. The same order was found previously for high initial temperatures. The low-temperature data were also found to extend the linear correlations between maximum flame speed and calculated equilibrium active-radical concentrations, which were established by the previously reported high-temperature data.

  9. Geomagnetic activity and polar surface air temperature variability

    NASA Astrophysics Data System (ADS)

    Seppälä, A.; Randall, C. E.; Clilverd, M. A.; Rozanov, E.; Rodger, C. J.

    2009-10-01

    Here we use the ERA-40 and ECMWF operational surface level air temperature data sets from 1957 to 2006 to examine polar temperature variations during years with different levels of geomagnetic activity, as defined by the A p index. Previous modeling work has suggested that NO x produced at high latitudes by energetic particle precipitation can eventually lead to detectable changes in surface air temperatures (SATs). We find that during winter months, polar SATs in years with high A p index are different than in years with low A p index; the differences are statistically significant at the 2-sigma level and range up to about ±4.5 K, depending on location. The temperature differences are larger when years with wintertime Sudden Stratospheric Warmings (SSWs) are excluded. We take into account solar irradiance variations, unlike previous analyses of geomagnetic effects in ERA-40 and operational data. Although we cannot conclusively show that the polar SAT patterns are physically linked by geomagnetic activity, we conclude that geomagnetic activity likely plays a role in modulating wintertime surface air temperatures. We tested our SAT results against variation in the Quasi Biennial Oscillation, the El Niño Southern Oscillation and the Southern Annular Mode. The results suggested that these were not driving the observed polar SAT variability. However, significant uncertainty is introduced by the Northern Annular Mode, and we cannot robustly exclude a chance linkage between sea surface temperature variability and geomagnetic activity.

  10. Drier Air, Lower Temperatures, and Triggering of Paroxysmal Atrial Fibrillation

    PubMed Central

    Nguyen, Jennifer L.; Link, Mark S.; Luttmann-Gibson, Heike; Laden, Francine; Schwartz, Joel; Wessler, Benjamin S.; Mittleman, Murray A.; Gold, Diane R.; Dockery, Douglas W.

    2015-01-01

    Background The few previous studies on the onset of paroxysmal atrial fibrillation and meteorologic conditions have focused on outdoor temperature and hospital admissions, but hospital admissions are a crude indicator of atrial fibrillation incidence, and studies have found other weather measures in addition to temperature to be associated with cardiovascular outcomes. Methods Two hundred patients with dual chamber implantable cardioverter-defibrillators were enrolled and followed prospectively from 2006 to 2010 for new onset episodes of atrial fibrillation. The date and time of arrhythmia episodes documented by the implanted cardioverter-defibrillators were linked to meteorologic data and examined using a case-crossover analysis. We evaluated associations with outdoor temperature, apparent temperature, air pressure, and three measures of humidity (relative humidity, dew point, and absolute humidity). Results Of the 200 enrolled patients, 49 patients experienced 328 atrial fibrillation episodes lasting ≥30 seconds. Lower temperatures in the prior 48 hours were positively associated with atrial fibrillation. Lower absolute humidity (ie, drier air) had the strongest and most consistent association: each 0.5 g/m3 decrease in the prior 24 hours increased the odds of atrial fibrillation by 4% (95% confidence interval [CI]: 0%, 7%) and by 5% (95% CI: 2%, 8%) for exposure in the prior 2 hours. Results were similar for dew point but slightly weaker. Conclusions Recent exposure to drier air and lower temperatures were associated with the onset of atrial fibrillation among patients with known cardiac disease, supporting the hypothesis that meteorologic conditions trigger acute cardiovascular episodes. PMID:25756220

  11. The importance of the diurnal and annual cycle of air traffic for contrail radiative forcing

    NASA Astrophysics Data System (ADS)

    Stuber, Nicola; Forster, Piers; Rädel, Gaby; Shine, Keith

    2006-06-01

    Air traffic condensation trails, or contrails, are believed to have a net atmospheric warming effect, although one that is currently small compared to that induced by other sources of human emissions. However, the comparably large growth rate of air traffic requires an improved understanding of the resulting impact of aircraft radiative forcing on climate. Contrails have an effect on the Earth's energy balance similar to that of high thin ice clouds. Their trapping of outgoing longwave radiation emitted by the Earth and atmosphere (positive radiative forcing) is partly compensated by their reflection of incoming solar radiation (negative radiative forcing). On average, the longwave effect dominates and the net contrail radiative forcing is believed to be positive. Over daily and annual timescales, varying levels of air traffic, meteorological conditions, and solar insolation influence the net forcing effect of contrails. Here we determine the factors most important for contrail climate forcing using a sophisticated radiative transfer model for a site in southeast England, located in the entrance to the North Atlantic flight corridor. We find that night-time flights during winter (December to February) are responsible for most of the contrail radiative forcing. Night flights account for only 25 per cent of daily air traffic, but contribute 60 to 80 per cent of the contrail forcing. Further, winter flights account for only 22 per cent of annual air traffic, but contribute half of the annual mean forcing. These results suggest that flight rescheduling could help to minimize the climate impact of aviation.

  12. The importance of the diurnal and annual cycle of air traffic for contrail radiative forcing.

    PubMed

    Stuber, Nicola; Forster, Piers; Rädel, Gaby; Shine, Keith

    2006-06-15

    Air traffic condensation trails, or contrails, are believed to have a net atmospheric warming effect, although one that is currently small compared to that induced by other sources of human emissions. However, the comparably large growth rate of air traffic requires an improved understanding of the resulting impact of aircraft radiative forcing on climate. Contrails have an effect on the Earth's energy balance similar to that of high thin ice clouds. Their trapping of outgoing longwave radiation emitted by the Earth and atmosphere (positive radiative forcing) is partly compensated by their reflection of incoming solar radiation (negative radiative forcing). On average, the longwave effect dominates and the net contrail radiative forcing is believed to be positive. Over daily and annual timescales, varying levels of air traffic, meteorological conditions, and solar insolation influence the net forcing effect of contrails. Here we determine the factors most important for contrail climate forcing using a sophisticated radiative transfer model for a site in southeast England, located in the entrance to the North Atlantic flight corridor. We find that night-time flights during winter (December to February) are responsible for most of the contrail radiative forcing. Night flights account for only 25 per cent of daily air traffic, but contribute 60 to 80 per cent of the contrail forcing. Further, winter flights account for only 22 per cent of annual air traffic, but contribute half of the annual mean forcing. These results suggest that flight rescheduling could help to minimize the climate impact of aviation. PMID:16778887

  13. Modeling daily average stream temperature from air temperature and watershed area

    NASA Astrophysics Data System (ADS)

    Butler, N. L.; Hunt, J. R.

    2012-12-01

    Habitat restoration efforts within watersheds require spatial and temporal estimates of water temperature for aquatic species especially species that migrate within watersheds at different life stages. Monitoring programs are not able to fully sample all aquatic environments within watersheds under the extreme conditions that determine long-term habitat viability. Under these circumstances a combination of selective monitoring and modeling are required for predicting future geospatial and temporal conditions. This study describes a model that is broadly applicable to different watersheds while using readily available regional air temperature data. Daily water temperature data from thirty-eight gauges with drainage areas from 2 km2 to 2000 km2 in the Sonoma Valley, Napa Valley, and Russian River Valley in California were used to develop, calibrate, and test a stream temperature model. Air temperature data from seven NOAA gauges provided the daily maximum and minimum air temperatures. The model was developed and calibrated using five years of data from the Sonoma Valley at ten water temperature gauges and a NOAA air temperature gauge. The daily average stream temperatures within this watershed were bounded by the preceding maximum and minimum air temperatures with smaller upstream watersheds being more dependent on the minimum air temperature than maximum air temperature. The model assumed a linear dependence on maximum and minimum air temperature with a weighting factor dependent on upstream area determined by error minimization using observed data. Fitted minimum air temperature weighting factors were consistent over all five years of data for each gauge, and they ranged from 0.75 for upstream drainage areas less than 2 km2 to 0.45 for upstream drainage areas greater than 100 km2. For the calibration data sets within the Sonoma Valley, the average error between the model estimated daily water temperature and the observed water temperature data ranged from 0.7

  14. Advances in Fast Response Acoustically Derived Air Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Bogoev, Ivan; Jacobsen, Larry; Horst, Thomas; Conrad, Benjamin

    2016-04-01

    Fast-response accurate air-temperature measurements are required when estimating turbulent fluxes of heat, water and carbon dioxide by open-path eddy-covariance technique. In comparison with contact thermometers like thermocouples, ultra-sonic thermometers do not suffer from solar radiation loading, water vapor condensation and evaporative cooling effects. Consequently they have the potential to provide more accurate true air temperature measurements. The absolute accuracy of the ultrasonic thermometer is limited by the following parameters: the distance between the transducer pairs, transducer delays associated with the electrical-acoustic signal conversion that vary with temperature, components of the wind vector that are normal to the ultrasonic paths, and humidity. The distance between the transducer pairs is commonly obtained by coordinate measuring machine. Improved accuracy demonstrated in this study results from increased stiffness in the anemometer head to better maintain the ultrasonic path-length distances. To further improve accuracy and account for changes in transducer delays and distance as a function of temperature, these parameters are characterized in a zero-wind chamber over the entire operating temperature range. When the sonic anemometer is combined with a co-located fast-response water vapor analyzer, like in the IRGASON instrument, speed of sound can be compensated for humidity effects on a point-by-point basis resulting in a true fast-response air temperature measurement. Laboratory test results show that when the above steps are implemented in the calibration of the ultrasonic thermometer air-temperature accuracy better than ±0.5 degrees Celsius can be achieved over the entire operating range. The approach is also validated in a field inter-comparison with an aspirated thermistor probe mounted in a radiation shield.

  15. The mass and speed dependence of meteor air plasma temperatures

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  16. CARS Temperature and Species Measurements For Air Vehicle Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Gord, James R.; Grisch, Frederic; Klimenko, Dmitry; Clauss, Walter

    2005-01-01

    The coherent anti-Stokes Raman spectroscopy (CARS) method has recently been used in the United States and Europe to probe several different types of propulsion systems for air vehicles. At NASA Langley Research Center in the United States, CARS has been used to simultaneously measure temperature and the mole fractions of N2, O2 and H2 in a supersonic combustor, representative of a scramjet engine. At Wright- Patterson Air Force Base in the United States, CARS has been used to simultaneously measure temperature and mole fractions of N2, O2 and CO2, in the exhaust stream of a liquid-fueled, gas-turbine combustor. At ONERA in France and the DLR in Germany researchers have used CARS to measure temperature and species concentrations in cryogenic LOX-H2 rocket combustion chambers. The primary aim of these measurements has been to provide detailed flowfield information for computational fluid dynamics (CFD) code validation.

  17. Microwave temperature profiler for clear air turbulence prediction

    NASA Technical Reports Server (NTRS)

    Gary, Bruce L. (Inventor)

    1992-01-01

    A method is disclosed for determining Richardson Number, Ri, or its reciprocal, RRi, for clear air prediction using measured potential temperature and determining the vertical gradient of potential temperature, d(theta)/dz. Wind vector from the aircraft instrumentation versus potential temperature, dW/D(theta), is determined and multiplies by d(theta)/dz to obtain dW/dz. Richardson number or its reciprocal is then determined from the relationship Ri = K(d theta)/dz divided by (dW/dz squared) for use in detecting a trend toward a threshold value for the purpose of predicting clear air turbulence. Other equations for this basic relationship are disclosed together with the combination of other atmospheric observables using multiple regression techniques.

  18. Symmetric scaling properties in global surface air temperature anomalies

    NASA Astrophysics Data System (ADS)

    Varotsos, Costas A.; Efstathiou, Maria N.

    2015-08-01

    We have recently suggested "long-term memory" or internal long-range correlation within the time-series of land-surface air temperature (LSAT) anomalies in both hemispheres. For example, an increasing trend in the LSAT anomalies is followed by another one at a different time in a power-law fashion. However, our previous research was mainly focused on the overall long-term persistence, while in the present study, the upward and downward scaling dynamics of the LSAT anomalies are analysed, separately. Our results show that no significant fluctuation differences were found between the increments and decrements in LSAT anomalies, over the whole Earth and over each hemisphere, individually. On the contrary, the combination of land-surface air and sea-surface water temperature anomalies seemed to cause a departure from symmetry and the increments in the land and sea surface temperature anomalies appear to be more persistent than the decrements.

  19. Evaluation of Annual Performance of Multi-type Air-Conditioners for Buildings

    NASA Astrophysics Data System (ADS)

    Watanabe, Choyu; Ohashi, Ei-Ichiro; Nagamatsu, Katsuaki; Nakayama, Hiroshi; Hirota, Masafumi

    In this paper, firstly the results of the partial thermal load performance tests of multi-type air-conditioners for buildings were shown. Tests were conducted by using the air-enthalpy method testing apparatus. Two types of air-conditioners, heat pump driven by electric motors (EHP) and that driven by gas engines (GHP), with a rated cooling capacity of 56 kW were tested. The coefficient of performance (COP) and the annual energy consumption measured by the above mentioned tests were closely compared with those predicted by JIS. In EHP,the measured COP indicates the maximum when the indoor thermal load is about 50% of the rated capacity, while COP in GHP decreases gradually as the thermal load is decreased. Based on these results, we examined the accuracies of COP and the annual energy consumption predicted by JIS. It was found that in both EHP and GHP the current calculating method prescribed in JIS could not duplicate the COP decrease that appeared under the low thermal load conditions. As a result, the annual energy consumption is seriously underestimated by JIS. The prediction errors of the annual energy consumption amounted to about 17% for EHP and 38% for GHP

  20. Fiber optic distributed temperature sensing for the determination of air temperature

    NASA Astrophysics Data System (ADS)

    de Jong, S. A. P.; Slingerland, J. D.; van de Giesen, N. C.

    2015-01-01

    This paper describes a method to correct for the effect of solar radiation in atmospheric distributed temperature sensing (DTS) applications. By using two cables with different diameters, one can determine what temperature a zero diameter cable would have. Such a virtual cable would not be affected by solar heating and would take on the temperature of the surrounding air. With two unshielded cable pairs, one black pair and one white pair, good results were obtained given the general consensus that shielding is needed to avoid radiation errors (WMO, 2010). The correlations between standard air temperature measurements and air temperatures derived from both cables of colors had a high correlation coefficient (r2=0.99) and a RMSE of 0.38 °C, compared to a RMSE of 2.40 °C for a 3.0 mm uncorrected black cable. A thin white cable measured temperatures that were close to air temperature measured with a nearby shielded thermometer (RMSE of 0.61 °C). The temperatures were measured along horizontal cables with an eye to temperature measurements in urban areas, but the same method can be applied to any atmospheric DTS measurements, and for profile measurements along towers or with balloons and quadcopters.

  1. The Effects of Air Pollution and Temperature on COPD

    PubMed Central

    Hansel, Nadia N.; McCormack, Meredith C.; Kim, Victor

    2016-01-01

    Chronic Obstructive Pulmonary Disease (COPD) affects 12–16 million people in the United States and is the third-leading cause of death. In developed countries, smoking is the greatest risk factor for the development of COPD, but other exposures also contribute to the development and progression of the disease. Several studies suggest, though are not definitive, that outdoor air pollution exposure is linked to the prevalence and incidence of COPD. Among individuals with COPD, outdoor air pollutants are associated with loss of lung function and increased respiratory symptoms. In addition, outdoor air pollutants are also associated with COPD exacerbations and mortality. There is much less evidence for the impact of indoor air on COPD, especially in developed countries in residences without biomass exposure. The limited existing data suggests that indoor particulate matter and nitrogen dioxide concentrations are linked to increased respiratory symptoms among patients with COPD. In addition, with the projected increases in temperature and extreme weather events in the context of climate change there has been increased attention to the effects of heat exposure. Extremes of temperature—both heat and cold—have been associated with increased respiratory morbidity in COPD. Some studies also suggest that temperature may modify the effect of pollution exposure and though results are not conclusive, understanding factors that may modify susceptibility to air pollution in patients with COPD is of utmost importance. PMID:26683097

  2. Spatial interpolation of monthly mean air temperature data for Latvia

    NASA Astrophysics Data System (ADS)

    Aniskevich, Svetlana

    2016-04-01

    Temperature data with high spatial resolution are essential for appropriate and qualitative local characteristics analysis. Nowadays the surface observation station network in Latvia consists of 22 stations recording daily air temperature, thus in order to analyze very specific and local features in the spatial distribution of temperature values in the whole Latvia, a high quality spatial interpolation method is required. Until now inverse distance weighted interpolation was used for the interpolation of air temperature data at the meteorological and climatological service of the Latvian Environment, Geology and Meteorology Centre, and no additional topographical information was taken into account. This method made it almost impossible to reasonably assess the actual temperature gradient and distribution between the observation points. During this project a new interpolation method was applied and tested, considering auxiliary explanatory parameters. In order to spatially interpolate monthly mean temperature values, kriging with external drift was used over a grid of 1 km resolution, which contains parameters such as 5 km mean elevation, continentality, distance from the Gulf of Riga and the Baltic Sea, biggest lakes and rivers, population density. As the most appropriate of these parameters, based on a complex situation analysis, mean elevation and continentality was chosen. In order to validate interpolation results, several statistical indicators of the differences between predicted values and the values actually observed were used. Overall, the introduced model visually and statistically outperforms the previous interpolation method and provides a meteorologically reasonable result, taking into account factors that influence the spatial distribution of the monthly mean temperature.

  3. Air pollution, temperature and pediatric influenza in Brisbane, Australia.

    PubMed

    Xu, Zhiwei; Hu, Wenbiao; Williams, Gail; Clements, Archie C A; Kan, Haidong; Tong, Shilu

    2013-09-01

    Previous studies have demonstrated the importance of weather variables in influencing the incidence of influenza. However, the role of air pollution is often ignored in identifying the environmental drivers of influenza. This research aims to examine the impacts of air pollutants and temperature on the incidence of pediatric influenza in Brisbane, Australia. Lab-confirmed daily data on influenza counts among children aged 0-14years in Brisbane from 2001 January 1st to 2008 December 31st were retrieved from Queensland Health. Daily data on maximum and minimum temperatures for the same period were supplied by the Australian Bureau of Meteorology. Winter was chosen as the main study season due to it having the highest pediatric influenza incidence. Four Poisson log-linear regression models, with daily pediatric seasonal influenza counts as the outcome, were used to examine the impacts of air pollutants (i.e., ozone (O3), particulate matter≤10μm (PM10) and nitrogen dioxide (NO2)) and temperature (using a moving average of ten days for these variables) on pediatric influenza. The results show that mean temperature (Relative risk (RR): 0.86; 95% Confidence Interval (CI): 0.82-0.89) was negatively associated with pediatric seasonal influenza in Brisbane, and high concentrations of O3 (RR: 1.28; 95% CI: 1.25-1.31) and PM10 (RR: 1.11; 95% CI: 1.10-1.13) were associated with more pediatric influenza cases. There was a significant interaction effect (RR: 0.94; 95% CI: 0.93-0.95) between PM10 and mean temperature on pediatric influenza. Adding the interaction term between mean temperature and PM10 substantially improved the model fit. This study provides evidence that PM10 needs to be taken into account when evaluating the temperature-influenza relationship. O3 was also an important predictor, independent of temperature. PMID:23911338

  4. Large inter annual variation in air quality during the annual festival 'Diwali' in an Indian megacity.

    PubMed

    Parkhi, Neha; Chate, Dilip; Ghude, Sachin D; Peshin, Sunil; Mahajan, Anoop; Srinivas, Reka; Surendran, Divya; Ali, Kaushar; Singh, Siddhartha; Trimbake, Hanumant; Beig, Gufran

    2016-05-01

    A network of air quality and weather monitoring stations was established under the System of Air Quality Forecasting and Research (SAFAR) project in Delhi. We report observations of ozone (O3), nitrogen oxides (NOx), carbon monoxide (CO) and particulate matter (PM2.5 and PM10) before, during and after the Diwali in two consecutive years, i.e., November 2010 and October 2011. The Diwali days are characterised by large firework displays throughout India. The observations show that the background concentrations of particulate matter are between 5 and 10 times the permissible limits in Europe and the United States. During the Diwali-2010, the highest observed PM10 and PM2.5 mass concentration is as high as 2070µg/m3 and 1620μg/m(3), respectively (24hr mean), which was about 20 and 27 times to National Ambient Air Quality Standards (NAAQS). For Diwali-2011, the increase in PM10 and PM2.5 mass concentrations was much less with their peaks of 600 and of 390μg/m(3) respectively, as compared to the background concentrations. Contrary to previous reports, firework display was not found to strongly influence the NOx, and O3 mixing ratios, with the increase within the observed variability in the background. CO mixing ratios showed an increase. We show that the large difference in 2010 and 2011 pollutant concentrations is controlled by weather parameters. PMID:27155433

  5. Requirements for high-temperature air-cooled central receivers

    SciTech Connect

    Wright, J.D.; Copeland, R.J.

    1983-12-01

    The design of solar thermal central receivers will be shaped by the end user's need for energy. This paper identifies the requirements for receivers supplying heat for industrial processes or electric power generation in the temperature range 540 to 1000/sup 0/C and evaluates the effects of the requirements on air-cooled central receivers. Potential IPH applications are identified as large baseload users that are located some distance from the receiver. In the electric power application, the receiver must supply heat to a pressurized gas power cycle. The difficulty in providing cost-effective thermal transport and thermal storage for air-cooled receivers is a critical problem.

  6. Can air temperature be used to project influences of climate change on stream temperature?

    USGS Publications Warehouse

    Arismendi, Ivan; Safeeq, Mohammad; Dunham, Jason B.; Johnson, Sherri L.

    2014-01-01

    Worldwide, lack of data on stream temperature has motivated the use of regression-based statistical models to predict stream temperatures based on more widely available data on air temperatures. Such models have been widely applied to project responses of stream temperatures under climate change, but the performance of these models has not been fully evaluated. To address this knowledge gap, we examined the performance of two widely used linear and nonlinear regression models that predict stream temperatures based on air temperatures. We evaluated model performance and temporal stability of model parameters in a suite of regulated and unregulated streams with 11–44 years of stream temperature data. Although such models may have validity when predicting stream temperatures within the span of time that corresponds to the data used to develop them, model predictions did not transfer well to other time periods. Validation of model predictions of most recent stream temperatures, based on air temperature–stream temperature relationships from previous time periods often showed poor performance when compared with observed stream temperatures. Overall, model predictions were less robust in regulated streams and they frequently failed in detecting the coldest and warmest temperatures within all sites. In many cases, the magnitude of errors in these predictions falls within a range that equals or exceeds the magnitude of future projections of climate-related changes in stream temperatures reported for the region we studied (between 0.5 and 3.0 °C by 2080). The limited ability of regression-based statistical models to accurately project stream temperatures over time likely stems from the fact that underlying processes at play, namely the heat budgets of air and water, are distinctive in each medium and vary among localities and through time.

  7. Can air temperatures be used to project influences of climate change on stream temperatures?

    NASA Astrophysics Data System (ADS)

    Arismendi, I.; Safeeq, M.; Dunham, J.; Johnson, S. L.

    2013-12-01

    The lack of available in situ stream temperature records at broad spatiotemporal scales have been recognized as a major limiting factor in the understanding of thermal behavior of stream and river systems. This has motivated the promotion of a wide variety of models that use surrogates for stream temperatures including a regression approach that uses air temperature as the predictor variable. We investigate the long-term performance of widely used linear and non-linear regression models between air and stream temperatures to project the latter in future climate scenarios. Specifically, we examine the temporal variability of the parameters that define each of these models in long-term stream and air temperature datasets representing relatively natural and highly human-influenced streams. We selected 25 sites with long-term records that monitored year-round daily measurements of stream temperature (daily mean) in the western United States (California, Oregon, Idaho, Washington, and Alaska). Surface air temperature data from each site was not available. Therefore, we calculated daily mean surface air temperature for each site in contiguous US from a 1/16-degree resolution gridded surface temperature data. Our findings highlight several limitations that are endemic to linear or nonlinear regressions that have been applied in many recent attempts to project future stream temperatures based on air temperature. Our results also show that applications over longer time periods, as well as extrapolation of model predictions to project future stream temperatures are unlikely to be reliable. Although we did not analyze a broad range of stream types at a continental or global extent, our analysis of stream temperatures within the set of streams considered herein was more than sufficient to illustrate a number of specific limitations associated with statistical projections of stream temperature based on air temperature. Radar plots of Nash-Sutcliffe efficiency (NSE) values for

  8. Persistence analysis of daily mean air temperature variation in Georgia

    NASA Astrophysics Data System (ADS)

    Matcharashvili, Teimuraz; Chelidze, Tamaz; Zhukova, Natalia; Mepharidze, Ekaterine; Sborshchikov, Alexander

    2010-05-01

    Extrapolation of observed linear trends is common practice in climate change researches on different scales. In this respect it is important, that though global warming is well established, the question of persistence of trends on regional scales remain controversial. Indeed, climate change for specific region and time by definition includes more than the simple average of weather conditions. Either random events or long-term changes, or more often combinations of them, can bring about significant swings in a variety of climate indicators from one time period to the next. Therefore in order to achieve further understanding of dynamics of climate change the character of stable peculiarities of analyzed dynamics should be investigated. Analysis of the character of long range correlations in climatological time series or peculiarities of their inherent memory is motivated exactly by this goal. Such analysis carried out on a different scales may help to understand spatial and temporal features of regional climate change. In present work the problem of persistence of observed trends in air temperature time series in Georgia was investigated. Longest available mean daily temperature time series of Tbilisi (1890-2008) were analyzed. Time series on shorter time scales of five stations in the West and East Georgia also were considered as well as monthly mean temperature time series of five stations. Additionally, temporally and spatially averaged daily and monthly mean air temperature time series were analyzed. Extent of persistence in mentioned time series were evaluated using R/S analysis calculation. Detrended and Multifractal Detrended Fluctuation Analysis as well as multi scaling analysis based on CWT have been used. Our results indicate that variation of daily or monthly mean temperatures reveals clear antipersistence on whole available time scale. It seems that antipersistence on global scale is general characteristics of mean air temperature variation and is not

  9. Historical changes in air temperature are evident in temperature fluxes measured in the sub-soil.

    NASA Astrophysics Data System (ADS)

    Fraser, Fiona; McCormick, Benjamin; Hallett, Paul; Wookey, Philip; Hopkins, David

    2013-04-01

    Warming trends in soil temperature have implications for a plethora of soil processes, including exacerbated climate change through the net release of greenhouse gases. Whereas long-term datasets of air temperature changes are abundant, a search of scientific literature reveals a lack of information on soil temperature changes and their specific consequences. We analysed five long-term data series collected in the UK (Dundee and Armagh) and Canada (Charlottetown, Ottawa and Swift Current). They show that the temperatures of soils at 5 - 20 cm depth, and sub-soils at 30 - 150 cm depth, increased in line with air temperature changes over the period 1958 - 2003. Differences were found, however, between soil and air temperatures when data were sub-divided into seasons. In spring, soil temperature warming ranged from 0.19°C at 30 cm in Armagh to 4.30°C at 50 cm in Charlottetown. In summer, however, the difference was smaller and ranged from 0.21°C at 10 cm in Ottawa to 3.70°C at 50 cm in Charlottetown. Winter temperatures were warmer in soil and ranged from 0.45°C at 5 cm in Charlottetown to 3.76°C at 150 cm in Charlottetown. There were significant trends in changes to soil temperature over time, whereas air temperature trends tended only to be significant in winter (changes range from 1.27°C in Armagh to 3.35°C in Swift Current). Differences in the seasonal warming patterns between air and soil temperatures have potential implications for the parameterization of models of biogeochemical cycling.

  10. RELATIONSHIP BETWEEN WATER TEMPERATURES AND AIR TEMPERATURES FOR CENTRAL US STREAMS

    EPA Science Inventory

    An analysis of the relationship between air and stream water temperature records for 11 rivers located in the central United States was conducted. he reliability of commonly available water temperature records was shown to be of unequal quality. imple linear relationships between...

  11. Air Temperature Estimation over the Third Pole Using MODIS LST

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Zhang, F.; Ye, M.; Che, T.

    2015-12-01

    The Third Pole is centered on the Tibetan Plateau (TP), which is the highest large plateau around the world with extremely complex terrain and climate conditions, resulting in very scarce meteorological stations especially in the vast west region. For these unobserved areas, the remotely sensed land surface temperature (LST) can greatly contribute to air temperature estimation. In our research we utilized the MODIS LST production from both TERRA and AQUA to estimate daily mean air temperature over the TP using multiple statistical models. Other variables used in the models include longitudes, latitudes, Julian day, solar zenith, NDVI and elevation. To select a relatively optimal model, we chose six popular and representative statistical models as candidate models including the multiple linear regression (MLR), the partial least squares regression (PLS), back propagate neural network (BPNN), support vector regression (SVR), random forests (RF) and Cubist regression (CR). The performances of the six models were compared for each possible combination of LSTs at four satellite pass times and two quality situations. Eventually a ranking table consisting of optimal models for each LST combination and quality situation was built up based on the validation results. By this means, the final production is generated providing daily mean air temperature with the least cloud blockage and acceptable accuracy. The average RMSEs of cross validation are mostly around 2℃. Stratified validations were also performed to test the expansibility to unobserved and high-altitude areas of the final models selected.

  12. The potential for reducing urban air temperatures and energy consumption through vegetative cooling

    SciTech Connect

    Kurn, D.M.; Bretz, S.E.; Huang, B.; Akbari, H.

    1994-05-01

    A network of 23 weather stations was used to detect existing oases in Southern California. Four stations, separated from one another by 15--25 miles (24--40 km), were closely examined. Data were strongly affected by the distance of the stations from the Pacific Ocean. This and other city-scale effects made the network inadequate for detection of urban oases. We also conducted traverse measurements of temperature and humidity in the Whittier Narrows Recreation Area in Los Angeles County on September 8--10, 1993. Near-surface air temperatures over vegetated areas were 1--2{degrees}C lower than background air temperatures. We estimate that vegetation may lower urban temperatures by 1{degrees}C, while the establishment of vegetative canopies may lower local temperatures by an additional 2{degrees}C. An increase in vegetation in residential neighborhoods may reduce peak loads in the Los Angeles area by 0.3 GW, and reduce energy consumption by 0.2 BkWh/year, saving $20 million annually. Large additional savings would result from regional cooling.

  13. Air Cooling for High Temperature Power Electronics (Presentation)

    SciTech Connect

    Waye, S.; Musselman, M.; King, C.

    2014-09-01

    Current emphasis on developing high-temperature power electronics, including wide-bandgap materials such as silicon carbide and gallium nitride, increases the opportunity for a completely air-cooled inverter at higher powers. This removes the liquid cooling system for the inverter, saving weight and volume on the liquid-to-air heat exchanger, coolant lines, pumps, and coolant, replacing them with just a fan and air supply ducting. We investigate the potential for an air-cooled heat exchanger from a component and systems-level approach to meet specific power and power density targets. A proposed baseline air-cooled heat exchanger design that does not meet those targets was optimized using a parametric computational fluid dynamics analysis, examining the effects of heat exchanger geometry and device location, fixing the device heat dissipation and maximum junction temperature. The CFD results were extrapolated to a full inverter, including casing, capacitor, bus bar, gate driver, and control board component weights and volumes. Surrogate ducting was tested to understand the pressure drop and subsequent system parasitic load. Geometries that met targets with acceptable loads on the system were down-selected for experimentation. Nine baseline configuration modules dissipated the target heat dissipation, but fell below specific power and power density targets. Six optimized configuration modules dissipated the target heat load, exceeding the specific power and power density targets. By maintaining the same 175 degrees C maximum junction temperature, an optimized heat exchanger design and higher device heat fluxes allowed a reduction in the number of modules required, increasing specific power and power density while still maintaining the inverter power.

  14. Global surface air temperature variations: 1851-1984

    SciTech Connect

    Jones, P.D.; Raper, S.C.B.; Kelly, P.M.

    1986-11-01

    Many attempts have been made to combine station surface air temperature data into an average for the Northern Hemisphere. Fewer attempts have been made for the Southern Hemisphere because of the unavailability of data from the Antarctic mainland before the 1950s and the uncertainty of making a hemispheric estimate based solely on land-based analyses for a hemisphere that is 80% ocean. Past estimates have been based largely on data from the World Weather Records (Smithsonian Institution, 1927, 1935, 1947, and U.S. Weather Bureau, 1959-82) and have been made without considerable effort to detect and correct station inhomogeneities. Better estimates for the Southern Hemisphere are now possible because of the availability of 30 years of climatological data from Antarctica. The mean monthly surface air temperature anomalies presented in this package for the than those previously published because of the incorporation of data previously hidden away in archives and the analysis of station homogeneity before estimation.

  15. Spatiotemporal changes in extreme ground surface temperatures and the relationship with air temperatures in the Three-River Source Regions during 1980-2013

    NASA Astrophysics Data System (ADS)

    Luo, Dongliang; Jin, Huijun; Lü, Lanzhi; Zhou, Jian

    2016-02-01

    Climate changes are affecting plant growth, ecosystem evolution, hydrological processes, and water resources in the Three-River Source Regions (TRSR). Daily ground surface temperature (GST) and air temperature (Ta) recordings from 12 meteorological stations illustrated trends and characteristics of extreme GST and Ta in the TRSR during 1980-2013. We used the Mann-Kendall test and Sen's slope estimate to analyze 12 temperature extreme indices as recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI). The mean annual ground surface temperatures (MAGST) are 2.4-4.3 °C higher than the mean annual air temperatures (MAAT) in the TRSR. The increasing trends of the MAGST are all higher than those of the MAAT. The multi-year average maximum GST (28.1 °C) is much higher than that of the Ta (7.6 °C), while the minimum GST (-8.7 °C) is similar to that of the minimum Ta (-6.9 °C). The minimum temperature trends are more significant than those of the maximum temperature and are consistent with temperature trends in other regions of China. Different spatiotemporal patterns of GST extremes compared to those of Ta may result from greater warming of the ground surface. Consequently, the difference between the GST and Ta increased. These findings have implications for variations of surface energy balance, sensible heat flux, ecology, hydrology, and permafrost.

  16. Interannual and interdecadal variability in United States surface-air temperatures, 1910-87

    USGS Publications Warehouse

    Dettinger, M.D.; Ghil, M.; Keppenne, C.L.

    1995-01-01

    Monthly mean surface-air temperatures at 870 sites in the contiguous United States were analyzed for interannual and interdecadal variability over the time interval 1910-87. The temperatures were analyzed spatially by empirical-orthogonal-function analysis and temporally by singularspectrum analysis (SSA). The dominant modes of spatio-temporal variability are trends and nonperiodic variations with time scales longer than 15 years, decadal-scale oscillations with periods of roughly 7 and 10 years, and interannual oscillations of 2.2 and 3.3 years. Together, these modes contribute about 18% of the slower-than-annual United States temperature variance. Two leading components roughly capture the mean hemispheric temperature trend and represent a long-term warming, largest in the southwest, accompanied by cooling of the domain's southeastern quadrant. The extremes of the 2.2-year interannual oscillation characterize temperature differences between the Northeastern and Southwestern States, whereas the 3.3-year cycle is present mostly in the Western States. The 7- to 10-year oscillations are much less regular and persistent than the interannual oscillations and characterize temperature differences between the western and interior sectors of the United States. These continental- or regional-scale temperature variations may be related to climatic variations with similar periodicities, either global or centered in other regions; such variations include quasi-biennial oscillations over the tropical Pacific or North Atlantic and quasi-triennial oscillations of North Pacific sea-surface temperatures.

  17. Industrial applications of MHD high temperature air heater technology

    NASA Astrophysics Data System (ADS)

    Saari, D. P.; Fenstermacher, J. E.; White, L. R.; Marksberry, C. L.

    1981-12-01

    The MHD high temperature air heater (HTAH) requires technology beyond the current state-of-the-art of industrial regenerative heaters. Specific aspects of HTAH technology which may find other application include refractory materials and valves resistant to the high temperature, corrosive, slag-bearing gas, materials resistant to cyclic thermal stresses, high temperature support structures for the cored brick bed, regenerative heater operating techniques for preventing accumulation of slag in the heater, and analytical tools for computing regenerative heater size, cost, and performance. Areas where HTAH technology may find application include acetylene/ethylene production processes, flash pyrolysis of coal, high temperature gas reactors, coal gasification processes, various metallurgical processes, waste incineration, and improvements to existing regenerator technology such as blast furnace stoves and glass tank regenerators.

  18. Evidence of Lunar Phase Influence on Global Surface Air Temperatures

    NASA Technical Reports Server (NTRS)

    Anyamba, Ebby; Susskind, Joel

    2000-01-01

    Intraseasonal oscillations appearing in a newly available 20-year record of satellite-derived surface air temperature are composited with respect to the lunar phase. Polar regions exhibit strong lunar phase modulation with higher temperatures occurs near full moon and lower temperatures at new moon, in agreement with previous studies. The polar response to the apparent lunar forcing is shown to be most robust in the winter months when solar influence is minimum. In addition, the response appears to be influenced by ENSO events. The highest mean temperature range between full moon and new moon in the polar region between 60 deg and 90 deg latitude was recorded in 1983, 1986/87, and 1990/91. Although the largest lunar phase signal is in the polar regions, there is a tendency for meridional equatorward progression of anomalies in both hemispheres so that the warning in the tropics occurs at the time of the new moon.

  19. Antarctic Sea ice variations and seasonal air temperature relationships

    NASA Technical Reports Server (NTRS)

    Weatherly, John W.; Walsh, John E.; Zwally, H. J.

    1991-01-01

    Data through 1987 are used to determine the regional and seasonal dependencies of recent trends of Antarctic temperature and sea ice. Lead-lag relationships involving regional sea ice and air temperature are systematically evaluated, with an eye toward the ice-temperature feedbacks that may influence climatic change. Over the 1958-1087 period the temperature trends are positive in all seasons. For the 15 years (l973-l987) for which ice data are available, the trends are predominantly positive only in winter and summer, and are most strongly positive over the Antarctic Peninsula. The spatially aggregated trend of temperature for this latter period is small but positive, while the corresponding trend of ice coverage is small but negative. Lag correlations between seasonal anomalies of the two variables are generally stronger with ice lagging the summer temperatures and with ice leading the winter temperatures. The implication is that summer temperatures predispose the near-surface waters to above-or below-normal ice coverage in the following fall and winter.

  20. Are there evidences of altitudinal effects of air temperature trends in the European Alps 1820-2013?

    NASA Astrophysics Data System (ADS)

    Schoener, W.; Auer, I.; Chimani, B.; Garnekind, M.; Haslinger, K.

    2013-12-01

    We use the HISTALP data set (www.zamg.ac.at/histalp) in order to assess the elevation dependency of air temperature trends within the European Alps. The evidence of altitudinal effects of the climate warming (with higher sensitivity of high mountain regions to warming) is a key statement, or at least key hypothesis, in many studies. The high relevance of such statement resp. hypothesis is obvious if one consider the impacts resulting from such fact, such as snow- and glacier melting and related effects for mountain hydrology. The HISTALP data set stands out with respect to its series lengths and its high level of homogenisation. Interestingly, the HISTALP temperature data show no clear altitudinal dependency of warming or cooling trends within the period 1820-2013. Additionally, a rather homogenous temporal trend could be observed within the entire Greater Alpine Region (GAR). Because HISTALP include also air pressure and vapour pressure series, we could compare our measured air temperatures with mean-column air temperatures, computed by the barometric formula, which were derived from the independently measured air pressure data (using vapour pressure to account for the atmospheric water content) at low resp. high elevations. Computed mean column temperatures are in good agreement with observed temperatures, indicating generally homogenous temporal temperature trend behaviour at different elevations. Our finding contradicts several results from climate modelling attempts and also other studies investigating Alpine temperature trends. We conclude that, whereas modelling results are still limited in the assessment of altitudinal effect of temperature trends from missing atmospheric processes captured by the models, the difference of the trend behaviour compared to other analyses of instrumental air temperatures comes from the seasonal base taken as the basis for trend estimation. It appears that opposite trend in spring and autumn for the period 1980

  1. Annual minimum temperature variations in early 21st century in Punjab, Pakistan

    NASA Astrophysics Data System (ADS)

    Jahangir, Misbah; Maria Ali, Syeda; Khalid, Bushra

    2016-01-01

    Climate change is a key emerging threat to the global environment. It imposes long lasting impacts both at regional and national level. In the recent era, global warming and extreme temperatures have drawn great interest to the scientific community. As in a past century considerable increase in global surface temperatures have been observed and predictions revealed that it will continue in the future. In this regard, current study mainly focused on analysis of regional climatic change (annual minimum temperature trends and its correlation with land surface temperatures in the early 21st century in Punjab) for a period of 1979-2013. The projected model data European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-Interim) has been used for eight Tehsils of Punjab i.e., annual minimum temperatures and annual seasonal temperatures. Trend analysis of annual minimum and annual seasonal temperature in (Khushab, Noorpur, Sargodha, Bhalwal, Sahiwal, Shahpur, Sillanwali and Chinoit) tehsils of Punjab was carried out by Regression analysis and Mann-Kendall test. Landsat 5 Thematic Mapper (TM) data was used in comparison with Model data for the month of May from the years 2000, 2009 and 2010. Results showed that no significant trends were observed in annual minimum temperature. A significant change was observed in Noorpur, Bhalwal, Shahpur, Sillanwali, Sahiwal, Chinoit and Sargodha tehsils during spring season, which indicated that this particular season was a transient period of time.

  2. Controls of air temperature variability over an Alpine Glacier

    NASA Astrophysics Data System (ADS)

    Shaw, Thomas; Brock, Ben; Ayala, Álvaro; Rutter, Nick

    2016-04-01

    Near surface air temperature (Ta) is one of the most important controls on energy exchange between a glacier surface and the overlying atmosphere. However, not enough detail is known about the controls on Ta across a glacier due to sparse data availability. Recent work has provided insights into variability of Ta along glacier centre-lines in different parts of the world, yet there is still a limited understanding of off-centreline variability in Ta and how best to estimate it from distant off-glacier locations. We present a new dataset of distributed 2m Ta records for the Tsanteleina Glacier in Northwest Italy from July-September, 2015. Data provide detailed information of lateral (across-glacier) and centre-line variations in Ta, with ~20,000 hourly observations from 17 locations. The suitability of different vertical temperature gradients (VTGs) in estimating air temperature is considered under a range of meteorological conditions and from different forcing locations. A key finding is that local VTGs account for a lot of Ta variability under a broad range of climatic conditions. However, across-glacier variability is found to be significant, particularly for high ambient temperatures and for localised topographic depressions. The relationship of spatial Ta patterns with regional-scale reanalysis data and alternative Ta estimation methodologies are also presented. This work improves the knowledge of local scale Ta variations and their importance to melt modelling.

  3. High efficiency power generation from coal and wastes utilizing high temperature air combustion technology (Part 2: Thermal performance of compact high temperature air preheater and MEET boiler)

    SciTech Connect

    Iwahashi, Takashi; Kosaka, Hitoshi; Yoshida, Nobuhiro

    1998-07-01

    The compact high temperature air preheater and the MEET boiler, which are critical components of the MEET system, are the direct evolutions of the high temperature air combustion technology. Innovative hardware concept for a compact high temperature air preheater has been proposed, and preliminary experiment using the MEET-I high temperature air preheater based on this concept successfully demonstrated continuous high temperature air generation with almost no temperature fluctuation. A preliminary heat transfer calculation for the MEET boiler showed that regenerative combustion using high temperature air is quite effective for radiative heat transfer augmentation in a boiler, which will lead to significant downsizing of a boiler. The heat transfer characteristics in the MEET boiler were experimentally measured and the heat transfer promotion effect and the uniform heat transfer field were confirmed. Moreover, it was understood that excellent combustion with the low BTU gas of about 3,000 kcal/m{sup 3} was done.

  4. Improving the energy efficiency of refrigeration plants by decreasing the temperature difference in air-cooled condensers

    NASA Astrophysics Data System (ADS)

    Shishov, V. V.; Talyzin, M. S.

    2015-09-01

    The electric energy consumption efficiency is estimated in comparing the real refrigeration machine cycle with the theoretical inverse Carnot cycle. The potential for saving electricity in using aircooled condensers with different values of temperature difference is shown. A procedure for calculating a refrigerating system with the evaporation temperature equal to -10°C, which corresponds at this temperature level to the thermal load of a standard supermarket, is described. The calculation was carried out taking into account the annual profile of temperatures in the indicated locality and based on the possibility of adjusting the condenser capacity for maintaining constant condensation temperature. The payback period in case of using condensers with different values of temperature difference is calculated; for example, in using condensers with a temperature difference of less than 15 K, the payback period will be less than one year. Decreasing the temperature difference results, on one hand, in a larger annual consumption of electric energy by the condenser fans, and on the other hand, it results in a lower condensation pressure, which leads to a smaller annual consumption of energy by the compressor unit. As a result, the total amount of energy consumed by the refrigeration system decreases so that despite a higher cost of condensers designed to operate at lower values of temperature difference, it becomes possible to achieve the above-mentioned payback period. Additionally, the payback period in case of using an air-cooled microchannel aluminum condenser was calculated: in case of using such a condenser with a temperature difference of 8 K instead of the condenser with the temperature difference equal to 15 K, the payback period will be less than half a year. Recommendations for designing new refrigeration systems equipped with air-cooled condensers are given.

  5. Air and Ground Surface Temperature Relations in a Mountainous Basin, Wolf Creek, Yukon Territory

    NASA Astrophysics Data System (ADS)

    Roadhouse, Emily A.

    The links between climate and permafrost are well known, but the precise nature of the relationship between air and ground temperatures remains poorly understood, particularly in complex mountain environments. Although previous studies indicate that elevation and potential incoming solar radiation (PISR) are the two leading factors contributing to the existence of permafrost at a given location, additional factors may also contribute significantly to the existence of mountain permafrost, including vegetation cover, snow accumulation and the degree to which individual mountain landscapes are prone to air temperature inversions. Current mountain permafrost models consider only elevation and aspect, and have not been able to deal with inversion effects in a systematic fashion. This thesis explores the relationship between air and ground surface temperatures and the presence of surface-based inversions at 27 sites within the Wolf Creek basin and surrounding area between 2001 and 2006, as a first step in developing an improved permafrost distribution TTOP model. The TTOP model describes the relationship between the mean annual air temperature and the temperature at the top of permafrost in terms of the surface and thermal offsets (Smith and Riseborough, 2002). Key components of this model are n-factors which relate air and ground climate by establishing the ratio between air and surface freezing (winter) and thawing (summer) degree-days, thus summarizing the surface energy balance on a seasonal basis. Here we examine (1) surface offsets and (2) freezing and thawing n-factor variability at a number of sites through altitudinal treeline in the southern Yukon. Thawing n-factors (nt) measured at individual sites remained relatively constant from one year to the next and may be related to land cover. During the winter, the insulating effect of a thick snow cover results in higher surface temperatures, while thin snow cover results in low surface temperatures more closely

  6. The Influence of Urbanization on Air Temperature in Nagqu County, Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Lin, Yun; Hu, Zeyong

    2016-04-01

    According to meteorological data obtained at Nagqu meteorological station, which is in the Nagqu County (NQ) and at site BJ of Nagqu Station of Plateau Climate and Environment (BJ), which is outside Nagqu County, the differences in air temperature (Ta) variations at NQ and BJ from 2001 to 2014 were compared and analyzed with respect of urbanization. Both the natural processes and human activities that could lead to the differences in Ta between NQ and BJ were studied in this study. Natural processes are characterized by meteorological variables such as wind, precipitation, sunshine hours, vapor pressure and the human activities are characterized by urbanization index. The results show that the annual mean temperature (Ta_mean) and annual mean minimum temperature (Ta_min) at NQ are higher than those at BJ from 2001 to 2014. But the annual mean maximum temperature (Ta_max) at NQ is smaller than that at BJ. The urbanization of Nagqu County has increased in the past fifteen years and reached to 27.24% in 2014. There are good agreements between Ta_max and natural factors including sunshine hours and water vapor pressure at NQ and BJ. And Ta_min has a positive relationship with human activities such as the GDP and population of Nagqu County. But the relationship between Ta_min with human activities at NQ is stronger than that at BJ. This is because BJ is a field site and the strength of human activity is weak. The Natural processes has a stronger influence on the variation of Ta_min at BJ than human activities do.

  7. Air Temperature estimation from Land Surface temperature and solar Radiation parameters

    NASA Astrophysics Data System (ADS)

    Lazzarini, Michele; Eissa, Yehia; Marpu, Prashanth; Ghedira, Hosni

    2013-04-01

    Air Temperature (AirT) is a fundamental parameter in a wide range of applications such as climate change studies, weather forecast, energy balance modeling, efficiency of Photovoltaic (PV) solar cells, etc. Air temperature data are generally obtained through regular measurements from meteorological stations. The distribution of these stations is normally sparse, so the spatial pattern of this parameter cannot be accurately estimated by interpolation methods. This work investigated the relationship between Air Temperature measured at meteorological stations and spatially contiguous measurements derived from Remote Sensing techniques, such as Land Surface Temperature (LST) maps, emissivity maps and shortwave radiation maps with the aim of creating a continuous map of AirT. For LST and emissivity, MSG-SEVIRI LST product from Land Surface Analysis Satellite Applications Facility (LSA-SAF) has been used. For shortwave radiation maps, an Artificial Neural Networks ensemble model has been developed and previously tested to create continuous maps from Global Horizontal Irradiance (GHI) point measurements, utilizing six thermal channels of MSG-SEVIRI. The testing sites corresponded to three meteorological stations located in the United Arab Emirates (UAE), where in situ measurements of Air Temperature were available. From the starting parameters, energy fluxes and net radiation have been calculated, in order to have information on the incoming and outgoing long-wave radiation and the incoming short-wave radiation. The preliminary analysis (day and Night measurements, cloud free) showed a strong negative correlation (0.92) between Outgoing long-wave radiation - GHI and LST- AirT, with a RMSE of 1.84 K in the AirT estimation from the initial parameters. Regression coefficients have been determined and tested on all the ground stations. The analysis also demonstrated the predominant impact of the incoming short-wave radiation in the AirT hourly variation, while the incoming

  8. Sensitivity of New England Stream Temperatures to Air Temperature and Precipitation Under Projected Climate

    NASA Astrophysics Data System (ADS)

    Huang, T.; Samal, N. R.; Wollheim, W. M.; Stewart, R. J.; Zuidema, S.; Prousevitch, A.; Glidden, S.

    2015-12-01

    The thermal response of streams and rivers to changing climate will influence aquatic habitat. This study examines the impact that changing climate has on stream temperatures in the Merrimack River, NH/MA USA using the Framework for Aquatic Modeling in the Earth System (FrAMES), a spatially distributed river network model driven by air temperature, air humidity, wind speed, precipitation, and solar radiation. Streamflow and water temperatures are simulated at a 45-second (latitude x longitude) river grid resolution for 135 years under historical and projected climate variability. Contemporary streamflow (Nash-Sutcliffe Coefficient = 0.77) and river temperatures (Nash-Sutcliffe Coefficient = 0.89) matched at downstream USGS gauge data well. A suite of model runs were made in combination with uniformly increased daily summer air temperatures by 2oC, 4 oC and 6 oC as well as adjusted precipitation by -40%, -30%, -20%, -10% and +10% as a sensitivity analysis to explore a broad range of potential future climates. We analyzed the summer stream temperatures and the percent of river length unsuitable for cold to warm water fish habitats. Impacts are greatest in large rivers due to the accumulation of river temperature warming throughout the entire river network. Cold water fish (i.e. brook trout) are most strongly affected while, warm water fish (i.e. largemouth bass) aren't expected to be impacted. The changes in stream temperatures under various potential climate scenarios will provide a better understanding of the specific impact that air temperature and precipitation have on aquatic thermal regimes and habitat.

  9. On extreme rainfall intensity increases with air temperature

    NASA Astrophysics Data System (ADS)

    Molnar, Peter; Fatichi, Simone; Paschalis, Athanasios; Gaal, Ladislav; Szolgay, Jan; Burlando, Paolo

    2016-04-01

    The water vapour holding capacity of air increases at about 7% per degree C according to the Clausius-Clapeyron (CC) relation. This is one of the arguments why a warmer future atmosphere, being able to hold more moisture, will generate higher extreme precipitation intensities. However, several empirical studies have recently demonstrated an increase in extreme rain intensities with air temperature above CC rates, in the range 7-14% per degree C worldwide (called super-CC rates). This was observed especially for shorter duration rainfall, i.e. in hourly and finer resolution data (e.g. review in Westra et al., 2014). The super-CC rate was attributed to positive feedbacks between water vapour and the updraft dynamics in convective clouds and lateral supply (convergence) of moisture. In addition, mixing of storm types was shown to be potentially responsible for super-CC rates in empirical studies. Assuming that convective events are accompanied by lightning, we will show on a large rainfall dataset in Switzerland (30 year records of 10-min and 1-hr data from 59 stations) that while the average rate of increase in extreme rainfall intensity (95th percentile) is 6-7% in no-lightning events and 8-9% in lightning events, it is 11-13% per degree C when all events are combined (Molnar et al., 2015). These results are relevant for climate change studies which predict shifts in storm types in a warmer climate in some parts of the world. The observation that extreme rain intensity and air temperature are positively correlated has consequences for the stochastic modelling of rainfall. Most current stochastic models do not explicitly include a direct rain intensity-air temperature dependency beyond applying factors of change predicted by climate models to basic statistics of precipitation. Including this dependency explicitly in stochastic models will allow, for example in the nested modelling approach of Paschalis et al. (2014), the random cascade disaggregation routine to be

  10. Linking geomagnetic activity and polar surface air temperature variability

    NASA Astrophysics Data System (ADS)

    Seppala, Annika

    ERA-40 and ECMWF operational surface level air temperature (SAT) data sets from 1957 to 2006 were used to examine polar temperature variations during years with different levels of geomagnetic activity, as defined by the Ap index. Previous modelling work has suggested that NOx produced at high latitudes by energetic particle precipitation can eventually lead to detectable changes in polar SATs. We find that during winter months, ERA-40 and ECMWF polar SATs in years with high Ap index are different than in years with low Ap index; the differences are statistically significant at the 2-sigma level and range up to about ±4.5 K, de-pending on location. The temperature differences are larger when years with wintertime Sudden Stratospheric Warmings are excluded. Solar irradiance variations were taken into account in the analysis. Although using the re-analysis and operational data sets it was not possible to conclusively show that the polar SAT patterns are physically linked by geomagnetic activity, we conclude that geomagnetic activity likely plays a role in modulating polar wintertime surface air temperature patterns. The SAT results were tested against variation in the Quasi Biennial Oscillation (QBO), the El Niño Southern Oscillation (ENSO) and the Southern Annular Mode n (SAM). The results suggested that these were not driving the observed polar SAT variability. However, significant uncertainty is introduced by the Northern Annular Mode (NAM) and we could not robustly exclude a chance linkage between sea surface temperature (SST) variability and geomagnetic activity. Examining the physical link between geomagnetic activity and polar surface temperature variability patterns using atmospheric models is an ongoing task.

  11. High Temperature Materials Laboratory User Program: 19th Annual Report, October 1, 2005 - September 30, 2006

    SciTech Connect

    Pasto, Arvid

    2007-08-01

    Annual Report contains overview of the High Temperature Materials Laboratory User Program and includes selected highlights of user activities for FY2006. Report is submitted to individuals within sponsoring DOE agency and to other interested individuals.

  12. Generation of low-temperature air plasma for food processing

    NASA Astrophysics Data System (ADS)

    Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya

    2015-11-01

    The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.

  13. The Trends of Soil Temperature Change Associated with Air Temperature Change in Korea from 1973 to 2012

    NASA Astrophysics Data System (ADS)

    Lee, Bo-Hyun; Park, Byeong-Hak; Koh, Eun-Hee; Lee, Kang-Kun

    2015-04-01

    Examining long-term trends of the soil temperature can contribute to assessing subsurface thermal environment. The recent 40-year (1973-2012) meteorological data from 14 Korea Meteorological Administration (KMA) stations was analyzed in this study to estimate the temporal variations of air and soil temperatures (at depths 0.5 and 1.0m) in Korea and their relations. The information on regional characteristics of study sites was also collected to investigate the local and regional features influencing the soil temperature. The long-term increasing trends of both air and soil temperatures were estimated by using simple linear regression analysis. The air temperature rise and soil temperature rise were compared for every site to reveal the relation between air and soil temperature changes. In most sites, the proportion of soil temperature rise to air temperature rise was nearly one to one except a few sites. The difference between the air and soil temperature trends at those sites may be attributed to the combined effect of soil properties such as thermal diffusivity and soil moisture content. The impact of urbanization on the air and soil temperature was also investigated in this study. Establishment of the relationship between the air and soil temperatures can help predicting the soil temperature change in a region where no soil temperature data is obtained by using air temperature data. For rigorous establishment of the relationship between soil and air temperatures, more thorough investigation on the soil thermal properties is necessary through additional monitoring and accompanied validation of the proposed relations. Keywords : Soil temperature, Air temperature, Cross-correlation analysis, Soil thermal diffusivity, Urbanization effect Acknowledgement This work was supported by the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+)" in "Water Resources Management Program (code 11 Technology Innovation C05

  14. Observations of northern latitude ground-surface and surface-air temperatures

    NASA Astrophysics Data System (ADS)

    Woodbury, Allan D.; Bhuiyan, A. K. M. H.; Hanesiak, John; Akinremi, O. O.

    2009-04-01

    Note that the magnitude of temperature increases reconstructed from borehole records seems to contrast with some proxy based reconstructions of surface air temperature (SAT) that indicate lower amounts of warming over the same period. We present data suggesting that ground and snow cover may bias climate reconstructions based on BT in portions of the Canadian northwest. Eight sites west of the Canadian cordillera, were examined for long-term SAT and GST changes. At seven of these sites precise borehole temperature profiles are used for the first time since the 1960s, thereby exploring the linkage between GST and SAT. New readings were made at four of these locations. All sites showed significant increasing SAT trends, in terms of annual mean minimum and maximum temperatures. Over a 54 year period, the minimum temperatures increased between 1.1°C and 1.5°C while the maximum increased between 0.8°C and 1.5°C, among those eight stations. Observations of GST at those sites, however, showed no obvious climate induced perturbations. Therefore, we believe that a trend in our area towards an increase in SAT temperatures only over the winter and spring is being masked by freeze thaw and latent energy effects. These results are important, particularly in northern locations where ground and snow cover may play an important role in creating a seasonal bias in GST reconstructions from borehole surveys.

  15. Impact of Air Temperature and SST Variability on Cholera Incidence in Southeastern Africa, 1971-2006

    NASA Astrophysics Data System (ADS)

    Paz, Shlomit

    2010-05-01

    The most important climatic parameter related to cholera outbreaks is the temperature, especially of the water bodies and the aquatic environment. This factor governs the survival and growth of V. cholerae, since it has a direct influence on its abundance in the environment, or alternatively, through its indirect influence on other aquatic organisms to which the pathogen is found to attach. Thus, the potential for cholera outbreaks may rise, parallel to the increase in ocean surface temperature. Indeed, recent studies indicate that global warming might create a favorable environment for V. cholerae and increase its incidence in vulnerable areas. Africa is vulnerable to climate variability. According to the recent IPCC report on Africa, the air temperature has indicated a significant warming trend since the 1960s. In recent years, most of the research into disease vectors in Africa related to climate variability has focused on malaria. The IPCC indicated that the need exists to examine the vulnerabilities and impacts of climatic factors on cholera in Africa. In light of this, the study uses a Poisson Regression Model to analyze the possible association between the cholera rates in southeastern Africa and the annual variability of air temperature and sea surface temperature (SST) at regional and hemispheric scales, for the period 1971-2006. Data description is as follows: Number of cholera cases per year in Uganda, Kenya, Rwanda, Burundi, Tanzania, Malawi, Zambia and Mozambique. Source: WHO Global Health Atlas - cholera. Seasonal and annual temperature time series: Regional scale: a) Air temperature for southeastern Africa (30° E-36° E, 5° S-17° S), source: NOAA NCEP-NCAR; b) Sea surface temperature, for the western Indian Ocean (0-20° S, 40° E-45° E), source: NOAA, Kaplan SST dataset. Hemispheric scale (for the whole Southern Hemisphere): a) Air temperature anomaly; b) Sea surface temperature anomaly. Source: CRU, University of East Anglia. The following

  16. Pan-Arctic linkages between snow accumulation and growing season air temperature, soil moisture and vegetation

    NASA Astrophysics Data System (ADS)

    Luus, K. A.; Gel, Y.; Lin, J. C.; Kelly, R. E. J.; Duguay, C. R.

    2013-01-01

    Arctic field studies have indicated that the air temperature, soil moisture and vegetation at a site influence the quantity of snow accumulated, and that snow accumulation can alter growing season soil moisture and vegetation. Climate change is predicted to bring about warmer air temperatures, greater snow accumulation and northward movements of the shrub and tree lines. Understanding the response of northern environments to changes in snow and growing season land surface characteristics requires: (1) insights into the present-day linkages between snow and growing season land surface characteristics; and (2) the ability to continue to monitor these associations over time across the vast pan-Arctic. The objective of this study was therefore to examine the pan-Arctic (north of 60° N) linkages between two temporally distinct data products created from AMSR-E satellite passive microwave observations: GlobSnow snow water equivalent, and NTSG (growing season air temperature, soil moisture and vegetation transmissivity). Due to the complex and interconnected nature of processes determining snow and growing season land surface characteristics, these associations were analyzed using the modern non-parametric technique of Alternating Conditional Expectations (ACE), as this approach does not impose a predefined analytic form. Findings indicate that regions with lower vegetation transmissivity (more biomass) at the start and end of the growing season tend to accumulate less snow at the start and end of the snow season, possibly due to interception and shading. Warmer air temperatures at the start and end of the growing season were associated with diminished snow accumulation at the start and end of the snow season. High latitude sites with warmer mean annual growing season temperatures tended to accumulate more snow, probably due to the greater availability of water vapor for snow season precipitation at warmer locations. Regions with drier soils preceding snow onset tended

  17. Savannah River Site radionuclide air emissions annual report for national emission standards for hazardous air pollutants

    SciTech Connect

    Sullivan, I.K.

    1993-12-31

    The radiological air emission sources at the SRS have been divided into three categories, Point, Grouped and Non-Point, for this report. Point sources, analyzed individually, are listed with a listing of the control devices, and the control device efficiency. The sources listed have been grouped together either for security reasons or where individual samples are composited for analytical purposes. For grouped sources the listed control devices may not be on all sources within a group. Point sources that did not have continuous effluent monitoring/sampling in 1993 are noted. The emissions from these sources was determined from Health Protection smear data, facility radionuclide content or other calculational methods, including process knowledge, utilizing existing analytical data. This report also contain sections on facility descriptions, dose assessment, and supplemental information.

  18. A note on the annual cycles of surface heat balance and temperature over a continent. [North America

    NASA Technical Reports Server (NTRS)

    Spar, J.; Crane, G.

    1974-01-01

    A surface heating function, defined as the ratio of the time derivative of the mean annual temperature curve to the surface heat balance, is computed from the annual temperature range and heat balance data for the North American continent. An annual cycle of the surface heat balance is then reconstructed from the surface heating function and the annual temperature curve, and an annual cycle of evaporative plus turbulent heat loss is recomputed from the annual cycles of radiation balance and surface heat balance for the continent. The implications of these results for long range weather forecasting are discussed.

  19. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  20. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  1. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  2. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  3. 14 CFR 25.1527 - Ambient air temperature and operating altitude.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ambient air temperature and operating... Information Operating Limitations § 25.1527 Ambient air temperature and operating altitude. The extremes of the ambient air temperature and operating altitude for which operation is allowed, as limited...

  4. Decadal power in land air temperatures: Is it statistically significant?

    NASA Astrophysics Data System (ADS)

    Thejll, Peter A.

    2001-12-01

    The geographical distribution and properties of the well-known 10-11 year signal in terrestrial temperature records is investigated. By analyzing the Global Historical Climate Network data for surface air temperatures we verify that the signal is strongest in North America and is similar in nature to that reported earlier by R. G. Currie. The decadal signal is statistically significant for individual stations, but it is not possible to show that the signal is statistically significant globally, using strict tests. In North America, during the twentieth century, the decadal variability in the solar activity cycle is associated with the decadal part of the North Atlantic Oscillation index series in such a way that both of these signals correspond to the same spatial pattern of cooling and warming. A method for testing statistical results with Monte Carlo trials on data fields with specified temporal structure and specific spatial correlation retained is presented.

  5. A new approach to quantifying soil temperature responses to changing air temperature and snow cover

    NASA Astrophysics Data System (ADS)

    Mackiewicz, Michael C.

    2012-08-01

    Seasonal snow cover provides an effective insulating barrier, separating shallow soil (0.25 m) from direct localized meteorological conditions. The effectiveness of this barrier is evident in a lag in the soil temperature response to changing air temperature. The causal relationship between air and soil temperatures is largely because of the presence or absence of snow cover, and is frequently characterized using linear regression analysis. However, the magnitude of the dampening effect of snow cover on the temperature response in shallow soils is obscured in linear regressions. In this study the author used multiple linear regression (MLR) with dummy predictor variables to quantify the degree of dampening between air and shallow soil temperatures in the presence and absence of snow cover at four Greenland sites. The dummy variables defining snow cover conditions were z = 0 for the absence of snow and z = 1 for the presence of snow cover. The MLR was reduced to two simple linear equations that were analyzed relative to z = 0 and z = 1 to enable validation of the selected equations. Compared with ordinary linear regression of the datasets, the MLR analysis yielded stronger coefficients of multiple determination and less variation in the estimated regression variables.

  6. Regional and large-scale influences on seasonal to interdecadal variability in Caribbean surface air temperature in CMIP5 simulations

    NASA Astrophysics Data System (ADS)

    Ryu, Jung-Hee; Hayhoe, Katharine

    2015-07-01

    We evaluate the ability of global climate models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP5) to reproduce observed seasonality and interannual variability of temperature over the Caribbean, and compare these with simulations from atmosphere-only (AMIP5) and previous-generation CMIP3 models. Compared to station and gridded observations, nearly every CMIP5, CMIP3 and AMIP5 simulation tends to reproduce the primary inter-regional features of the Caribbean annual temperature cycle. In most coupled model simulations, however, boreal summer temperature lags observations by about 1 month, with a similar lag in the simulated annual cycle of sea surface temperature (SST), and a systematic cold bias in both climatological annual mean air temperature and SST. There is some improvement from CMIP3 to CMIP5 but the bias is still marked compared to AMIP5 and observations, implying that biases in the annual temperature cycle may originate in the ocean component of the coupled models. This also suggests a tendency for models to over-emphasize the influence of SSTs on near-surface temperature, a bias that may be exacerbated by model tendency to over-estimate ocean mixed layer depth as well. In contrast, we find that both coupled and atmosphere-only models tend to reasonably simulate the response of observed temperature to global temperature, to regional and large-scale variability across the Caribbean region and the Gulf of Mexico, and even to more remote Atlantic and Pacific influences. These findings contribute to building confidence in the ability of coupled models to simulate the effect of global-scale change on the Caribbean.

  7. Complexity analysis of the air temperature and the precipitation time series in Serbia

    NASA Astrophysics Data System (ADS)

    Mimić, G.; Mihailović, D. T.; Kapor, D.

    2015-11-01

    In this paper, we have analyzed the time series of daily values for three meteorological elements, two continuous and a discontinuous one, i.e., the maximum and minimum air temperature and the precipitation. The analysis was done based on the observations from seven stations in Serbia from the period 1951-2010. The main aim of this paper was to quantify the complexity of the annual values for the mentioned time series and to calculate the rate of its change. For that purpose, we have used the sample entropy and the Kolmogorov complexity as the measures which can indicate the variability and irregularity of a given time series. Results obtained show that the maximum temperature has increasing trends in the given period which points out a warming, ranged in the interval 1-2 °C. The increasing temperature indicates the higher internal energy of the atmosphere, changing the weather patterns, manifested in the time series. The Kolmogorov complexity of the maximum temperature time series has statistically significant increasing trends, while the sample entropy has increasing but statistically insignificant trend. The trends of complexity measures for the minimum temperature depend on the location. Both complexity measures for the precipitation time series have decreasing trends.

  8. Assessing surface air temperature variability using quantile regression

    NASA Astrophysics Data System (ADS)

    Timofeev, A. A.; Sterin, A. M.

    2014-12-01

    Many researches in climate change currently involve linear trends, based on measured variables. And many of them only consider trends in mean values, whereas it is clear, that not only means, but also whole shape of distribution changes over time and requires careful assessment. For example extreme values including outliers may get bigger, while median has zero slope.Quantile regression provides a convenient tool, that enables detailed analysis of changes in full range of distribution by producing a vector of quantile trends for any given set of quantiles.We have applied quantile regression to surface air temperature observations made at over 600 weather stations across Russian Federation during last four decades. The results demonstrate well pronounced regions with similar values of significant trends in different parts of temperature value distribution (left tail, middle part, right tail). The uncertainties of quantile trend estimations for several spatial patterns of trends over Russia are estimated and analyzed for each of four seasons.For temperature trend estimation over vast territories, quantile regression is an effort consuming approach, but is more informative than traditional instrument, to assess decadal evolution of temperature values, including evolution of extremes.Partial support of ERA NET RUS ACPCA joint project between EU and RBRF 12-05-91656-ЭРА-А is highly appreciated.

  9. Peak fire temperatures and effects on annual plants in the Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    2002-01-01

    Very little is known about the behavior and effects of fire in the Mojave Desert, because fire was historically uncommon. However, fire has become more frequent since the 1970s with increased dominance of the invasive annual grasses Bromus rubens and Schismus spp., and land managers are concerned about its ecological effect. In this paper, I describe patterns of peak fire temperature and their effect on annual plants in creosote bush scrub vegetation of the Mojave Desert. Temperatures were monitored among microhabitats and distances from the soil surface, and between spring and summer. Microhabitats ranged from high amounts of fuel beneath creosote bush (Larrea tridentata) canopies, to intermediate amounts at the canopy drip line, to low amounts in the interspaces between them. Distances from the soil surface were within the vertical range where most annual plant seeds occur (-2, 0, 5, and 10 cm). I also compare temperature patterns with postfire changes in soil properties and annual plant biomass and species richness to infer potential mechanisms by which fires affect annual plants. Peak fire temperatures were most affected by the microhabitat fuel gradient, and the effects of fire on annual plants varied among microhabitats. Beneath creosote bushes, lethal fire temperatures for annual plant seeds occurred above- and belowground, resulting in four postfire years of reduced annual plant biomass and species richness due most likely to seed mortality, especially of Bromus rubens and native forbs. At the canopy drip line, lethal fire temperatures occurred only aboveground, reducing annual plant biomass for 1 yr and species richness for 2 yr, and increasing biomass of Schismus sp., the alien forb Erodium cicutarium, and native annuals after 3 yr. Negligible changes were caused by fire in interspaces or between spring and summer. Fire effects models for creosote bush scrub vegetation must account for patterns of peak fire temperature along the shrub-intershrub gradient

  10. Air Surface Temperature Correlation with Greenhouse Gases by Using Airs Data Over Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Rajab, Jasim Mohammed; MatJafri, M. Z.; Lim, H. S.

    2014-08-01

    The main objective of this study is to develop algorithms for calculating the air surface temperature (AST). This study also aims to analyze and investigate the effects of greenhouse gases (GHGs) on the AST value in Peninsular Malaysia. Multiple linear regression is used to achieve the objectives of the study. Peninsular Malaysia has been selected as the research area because it is among the regions of tropical Southeast Asia with the greatest humidity, pockets of heavy pollution, rapid economic growth, and industrialization. The predicted AST was highly correlated ( R = 0.783) with GHGs for the 6-year data (2003-2008). Comparisons of five stations in 2009 showed close agreement between the predicted AST and the observed AST from AIRS, especially in the wet season (within 1.3 K). The in situ data ranged from 1 to 2 K. Validation results showed that AST ( R = 0.776-0.878) has values nearly the same as the observed AST from AIRS. We found that O3 during the wet season was indicated by a strongly positive beta coefficient (0.264-0.992) with AST. The CO2 yields a reasonable relationship with temperature with low to moderate beta coefficient (-0.065 to 0.238). The O3, CO2, and environmental variables experienced different seasonal fluctuations that depend on weather conditions and topography. The concentration of gases and pollution were the highest over industrial zones and overcrowded cities, and the dry season was more polluted compared with the wet season. These results indicate the advantage of using the satellite AIRS data and a correlation analysis to investigate the effect of atmospheric GHGs on AST over Peninsular Malaysia. An algorithm that is capable of retrieving Peninsular Malaysian AST in all weather conditions with total uncertainties ranging from 1 to 2 K was developed.

  11. Cyclic Oxidation of High-Temperature Alloy Wires in Air

    NASA Technical Reports Server (NTRS)

    Reigel, Marissa M.

    2004-01-01

    High-temperature alloy wires are proposed for use in seal applications for future re-useable space vehicles. These alloys offer the potential for improved wear resistance of the seals. The wires must withstand the high temperature environments the seals are subjected to as well as maintain their oxidation resistance during the heating and cooling cycles of vehicle re-entry. To model this, the wires were subjected to cyclic oxidation in stagnant air. of this layer formation is dependent on temperature. Slow growing oxides such as chromia and alumina are desirable. Once the oxide is formed it can prevent the metal from further reacting with its environment. Cyclic oxidation models the changes in temperature these wires will undergo in application. Cycling the temperature introduces thermal stresses which can cause the oxide layer to break off. Re-growth of the oxide layer consumes more metal and therefore reduces the properties and durability of the material. were used for cyclic oxidation testing. The baseline material, Haynes 188, has a Co base and is a chromia former while the other two alloys, Kanthal A1 and PM2000, both have a Fe base and are alumina formers. Haynes 188 and Kanthal A1 wires are 250 pm in diameter and PM2000 wires are 150 pm in diameter. The coiled wire has a total surface area of 3 to 5 sq cm. The wires were oxidized for 11 cycles at 1204 C, each cycle containing a 1 hour heating time and a minimum 20 minute cooling time. Weights were taken between cycles. After 11 cycles, one wire of each composition was removed for analysis. The other wire continued testing for 70 cycles. Post-test analysis includes X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) for phase identification and morphology.

  12. Mortality of inshore marine mammals in eastern Australia is predicted by freshwater discharge and air temperature.

    PubMed

    Meager, Justin J; Limpus, Colin

    2014-01-01

    Understanding environmental and climatic drivers of natural mortality of marine mammals is critical for managing populations effectively and for predicting responses to climate change. Here we use a 17-year dataset to demonstrate a clear relationship between environmental forcing and natural mortality of inshore marine mammals across a subtropical-tropical coastline spanning a latitudinal gradient of 13° (>2000 km of coastline). Peak mortality of inshore dolphins and dugongs followed sustained periods of elevated freshwater discharge (9 months) and low air temperature (3 months). At a regional scale, these results translated into a strong relationship between annual mortality and an index of El Niño-Southern Oscillation. The number of cyclones crossing the coastline had a comparatively weak effect on inshore marine mammal mortality, and only in the tropics. Natural mortality of offshore/migratory cetaceans was not predicted by freshwater discharge, but was related to lagged air temperature. These results represent the first quantitative link between environmental forcing and marine mammal mortality in the tropics, and form the basis of a predictive tool for managers to prepare responses to periods of elevated marine mammal mortality. PMID:24740149

  13. Mortality of Inshore Marine Mammals in Eastern Australia Is Predicted by Freshwater Discharge and Air Temperature

    PubMed Central

    Meager, Justin J.; Limpus, Colin

    2014-01-01

    Understanding environmental and climatic drivers of natural mortality of marine mammals is critical for managing populations effectively and for predicting responses to climate change. Here we use a 17-year dataset to demonstrate a clear relationship between environmental forcing and natural mortality of inshore marine mammals across a subtropical-tropical coastline spanning a latitudinal gradient of 13° (>2000 km of coastline). Peak mortality of inshore dolphins and dugongs followed sustained periods of elevated freshwater discharge (9 months) and low air temperature (3 months). At a regional scale, these results translated into a strong relationship between annual mortality and an index of El Niño-Southern Oscillation. The number of cyclones crossing the coastline had a comparatively weak effect on inshore marine mammal mortality, and only in the tropics. Natural mortality of offshore/migratory cetaceans was not predicted by freshwater discharge, but was related to lagged air temperature. These results represent the first quantitative link between environmental forcing and marine mammal mortality in the tropics, and form the basis of a predictive tool for managers to prepare responses to periods of elevated marine mammal mortality. PMID:24740149

  14. Daily air temperature interpolated at high spatial resolution over a large mountainous region

    USGS Publications Warehouse

    Dodson, R.; Marks, D.

    1997-01-01

    Two methods are investigated for interpolating daily minimum and maximum air temperatures (Tmin and Tmax) at a 1 km spatial resolution over a large mountainous region (830 000 km2) in the U.S. Pacific Northwest. The methods were selected because of their ability to (1) account for the effect of elevation on temperature and (2) efficiently handle large volumes of data. The first method, the neutral stability algorithm (NSA), used the hydrostatic and potential temperature equations to convert measured temperatures and elevations to sea-level potential temperatures. The potential temperatures were spatially interpolated using an inverse-squared-distance algorithm and then mapped to the elevation surface of a digital elevation model (DEM). The second method, linear lapse rate adjustment (LLRA), involved the same basic procedure as the NSA, but used a constant linear lapse rate instead of the potential temperature equation. Cross-validation analyses were performed using the NSA and LLRA methods to interpolate Tmin and Tmax each day for the 1990 water year, and the methods were evaluated based on mean annual interpolation error (IE). The NSA method showed considerable bias for sites associated with vertical extrapolation. A correction based on climate station/grid cell elevation differences was developed and found to successfully remove the bias. The LLRA method was tested using 3 lapse rates, none of which produced a serious extrapolation bias. The bias-adjusted NSA and the 3 LLRA methods produced almost identical levels of accuracy (mean absolute errors between 1.2 and 1.3??C), and produced very similar temperature surfaces based on image difference statistics. In terms of accuracy, speed, and ease of implementation, LLRA was chosen as the best of the methods tested.

  15. Study of Ram-air Heat Exchangers for Reducing Turbine Cooling-air Temperature of a Supersonic Aircraft Turbojet Engine

    NASA Technical Reports Server (NTRS)

    Diaguila, Anthony J; Livingood, John N B; Eckert, Ernst R G

    1956-01-01

    The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude The sizes and weights of the cores of heat exchangers were determined analytically for possible application for reducing turbine cooling-air temperatures of an engine designed for a Mach number of 2.5 and an altitude of 70,000 feet. A compressor-bleed-air weight flow of 2.7 pounds per second was assumed for the coolant; ram air was considered as the other fluid. Pressure drops and inlet states of both fluids were prescribed, and ranges of compressor-bleed-air temperature reductions and of the ratio of compressor-bleed to ram-air weight flows were considered.

  16. Estimation of sampling error uncertainties in observed surface air temperature change in China

    NASA Astrophysics Data System (ADS)

    Hua, Wei; Shen, Samuel S. P.; Weithmann, Alexander; Wang, Huijun

    2016-06-01

    This study examines the sampling error uncertainties in the monthly surface air temperature (SAT) change in China over recent decades, focusing on the uncertainties of gridded data, national averages, and linear trends. Results indicate that large sampling error variances appear at the station-sparse area of northern and western China with the maximum value exceeding 2.0 K2 while small sampling error variances are found at the station-dense area of southern and eastern China with most grid values being less than 0.05 K2. In general, the negative temperature existed in each month prior to the 1980s, and a warming in temperature began thereafter, which accelerated in the early and mid-1990s. The increasing trend in the SAT series was observed for each month of the year with the largest temperature increase and highest uncertainty of 0.51 ± 0.29 K (10 year)-1 occurring in February and the weakest trend and smallest uncertainty of 0.13 ± 0.07 K (10 year)-1 in August. The sampling error uncertainties in the national average annual mean SAT series are not sufficiently large to alter the conclusion of the persistent warming in China. In addition, the sampling error uncertainties in the SAT series show a clear variation compared with other uncertainty estimation methods, which is a plausible reason for the inconsistent variations between our estimate and other studies during this period.

  17. Using Annual Data to Estimate the Public Health Impact of Extreme Temperatures.

    PubMed

    Goggins, William B; Yang, Chunyuh; Hokama, Tomiko; Law, Lewis S K; Chan, Emily Y Y

    2015-07-01

    Short-term associations between both hot and cold ambient temperatures and higher mortality have been found worldwide. Few studies have examined these associations on longer time scales. Age-standardized mortality rates (ASMRs) were calculated for 1976-2012 for Hong Kong SAR, People's Republic of China, defining "annual" time periods in 2 ways: from May through April of the following year and from November through October. Annual frequency and severity of extreme temperatures were summarized by using a degree-days approach with extreme heat expressed as annual degree-days >29.3°C and cold as annual degree-days <27.5°C. For example, a day with a mean temperature of 25.0°C contributes 2.5 cold degree-days to the annual total. Generalized additive models were used to estimate the association between annual hot and cold degree-days and the ASMR, with adjustment for long-term trends. Increases of 10 hot or 200 cold degree-days in an annual period, the approximate interquartile ranges for these variables, were significantly (all P's ≤ 0.011) associated with 1.9% or 3.1% increases, respectively, in the annual ASMR for the May-April analyses and with 2.2% or 2.8% increases, respectively, in the November-October analyses. Associations were stronger for noncancer and elderly mortality. Mortality increases associated with extreme temperature are not simply due to short-term forward displacement of deaths that would have occurred anyway within a few weeks. PMID:26009315

  18. The Role of Auxiliary Variables in Deterministic and Deterministic-Stochastic Spatial Models of Air Temperature in Poland

    NASA Astrophysics Data System (ADS)

    Szymanowski, Mariusz; Kryza, Maciej

    2015-11-01

    Our study examines the role of auxiliary variables in the process of spatial modelling and mapping of climatological elements, with air temperature in Poland used as an example. The multivariable algorithms are the most frequently applied for spatialization of air temperature, and their results in many studies are proved to be better in comparison to those obtained by various one-dimensional techniques. In most of the previous studies, two main strategies were used to perform multidimensional spatial interpolation of air temperature. First, it was accepted that all variables significantly correlated with air temperature should be incorporated into the model. Second, it was assumed that the more spatial variation of air temperature was deterministically explained, the better was the quality of spatial interpolation. The main goal of the paper was to examine both above-mentioned assumptions. The analysis was performed using data from 250 meteorological stations and for 69 air temperature cases aggregated on different levels: from daily means to 10-year annual mean. Two cases were considered for detailed analysis. The set of potential auxiliary variables covered 11 environmental predictors of air temperature. Another purpose of the study was to compare the results of interpolation given by various multivariable methods using the same set of explanatory variables. Two regression models: multiple linear (MLR) and geographically weighted (GWR) method, as well as their extensions to the regression-kriging form, MLRK and GWRK, respectively, were examined. Stepwise regression was used to select variables for the individual models and the cross-validation method was used to validate the results with a special attention paid to statistically significant improvement of the model using the mean absolute error (MAE) criterion. The main results of this study led to rejection of both assumptions considered. Usually, including more than two or three of the most significantly

  19. Daily Cycle of Air Temperature and Surface Temperature in Stone Forest

    NASA Astrophysics Data System (ADS)

    Wang, K.; Li, Y.; Wang, X.; Yuan, M.

    2013-12-01

    Urbanization is one of the most profound human activities that impact on climate change. In cities, where are highly artificial areas, the conflict between human activity and natural climate is particularly prominent. Urban areas always have the larger area of impervious land, the higher consumption of greenhouse gases, more emissions of anthropogenic heat and air pollution, all contribute to the urban warming phenomena. Understanding the mechanisms causing a variety of phenomena involved in the urban warming is critical to distinguish the anthropogenic effect and natural variation in the climate change. However, the exact dynamics of urban warming were poorly understood, and effective control strategies are not available. Here we present a study of the daily cycle of air temperature and surface temperature in Stone Forest. The specific heat of the stones in the Stone Forest and concrete of the man-made structures within the cities are approximate. Besides, the height of the Stone Forest and the height of buildings within the city are also similar. As a scenic area, the Stone Forest is being preserved and only opened for sightseeing. There is no anthropogenic heat, as well air pollution within the Stone Forest. The thermal environment in Stone Forest can be considered to be a simulation of thermal environment in the city, which can reveal the effect of man-made structures on urban thermal environment. We conducted the field studies and numerical analysis in the Stone Forest for 4 typical urban morphology and environment scenarios, including high-rise compact cities, low-rise sparse cities, garden cities and isolated single stone. Air temperature and relative humidity were measured every half an hour in 15 different locations, which within different spatial distribution of stones and can represent the four urban scenarios respectively. At the same time, an infrared camera was used to take thermal images and get the hourly surface temperatures of stones and

  20. Impacts of wind farms on surface air temperatures

    PubMed Central

    Baidya Roy, Somnath; Traiteur, Justin J.

    2010-01-01

    Utility-scale large wind farms are rapidly growing in size and numbers all over the world. Data from a meteorological field campaign show that such wind farms can significantly affect near-surface air temperatures. These effects result from enhanced vertical mixing due to turbulence generated by wind turbine rotors. The impacts of wind farms on local weather can be minimized by changing rotor design or by siting wind farms in regions with high natural turbulence. Using a 25-y-long climate dataset, we identified such regions in the world. Many of these regions, such as the Midwest and Great Plains in the United States, are also rich in wind resources, making them ideal candidates for low-impact wind farms. PMID:20921371

  1. Validation of annual average air concentration predictions from the AIRDOS-EPA computer code

    SciTech Connect

    Miller, C.W.; Fields, D.E.; Cotter, S.J.

    1981-01-01

    The AIRDOS-EPA computer code is used to assess the annual doses to the general public resulting from releases of radionuclides to the atmosphere by Oak Ridge National Laboratory (ORNL) facilities. This code uses a modified Gaussian plume equation to estimate air concentrations resulting from the release of a maximum of 36 radionuclides. Radionuclide concentrations in food products are estimated from the output of the atmospheric transport model using the terrestrial transport model described in US Nuclear Regulatory Commission Regulatory Guide 1.109. Doses to man at each distance and direction specified are estimated for up to eleven organs and five exposure modes. To properly use any environmental transport model, some estimate of the model's predictive accuracy must be obtained. Because of a lack of sufficient data for the ORNL site, one year of weekly average /sup 85/Kr concentrations observed at 13 stations located 30 to 150 km distant from an assumed-continuous point source at the Savannah River Plant, Aiken, South Carolina, have been used in a validation study of the atmospheric transport portion of AIRDOS-EPA. The predicted annual average concentration at each station exceeded the observed value in every case. The overprediction factor ranged from 1.4 to 3.4 with an average value of 2.4. Pearson's correlation between pairs of logarithms of observed and predicted values was r = 0.93. Based on a one-tailed students's test, we can be 98% confident that for this site under similar meteorological, release, and monitoring conditions no annual average air concentrations will be observed at the sampling stations in excess of those predicted by the code. As the averaging time of the prdiction decreases, however, the uncertainty in the prediction increases.

  2. Subseasonal variability of North American wintertime surface air temperature

    NASA Astrophysics Data System (ADS)

    Lin, Hai

    2015-09-01

    Using observational pentad data of the recent 34 Northern Hemisphere extended winters, subseasonal variability of surface air temperature (SAT) over North America is analyzed. The four leading modes of subseasonal SAT variability, that are identified with an empirical orthogonal function (EOF) analysis, account for about 60% of the total variance. The first (EOF1) and second (EOF2) modes are independent of other modes, and thus are likely controlled by distinct processes. The third (EOF3) and fourth (EOF4) modes, however, tend to have a phase shift to each other in space and time, indicating that part of their variability is related to a common process and represent a propagating pattern over North America. Lagged regression analysis is conducted to identify the precursors of large-scale atmospheric circulation for each mode a few pentads in advance, and to understand the processes that influence the subseasonal SAT variability and the predictability signal sources. EOF1 is found to be closely related to the Pacific-North American (PNA) circulation pattern and at least part of its variability is preceded by the East Asian cold surge. The cold surge leads to low-level convergence and enhanced convection in the tropical central Pacific which in turn induces the PNA. EOF2 tends to oscillate at a period of about 70 days, and is influenced by the low-frequency component of the Madden-Julian Oscillation (MJO). On the other hand, EOF3 and EOF4 are connected to the high-frequency part of the MJO which has a period range of 30-50 days. These findings would help understanding the mechanisms of subseasonal surface air temperature variability in North America and improving weather predictions on a subseasonal time scale.

  3. Trends in intra- and inter-annual temperature variabilities across Sudan.

    PubMed

    Elagib, Nadir Ahmed

    2010-01-01

    Four mean temperature variables, namely maximum (MAX), minimum (MIN), mean (MEAN) and diurnal temperature range (DTR), were considered for 14 selected observational stations throughout Sudan. The objectives were to investigate the seasonal and annual regimes, the seasonal and annual trends, the intra-annual variability (IAV) by the coefficient of variation (CV), and the interrelationships between the temperature variables and percent of possible sunshine. A mounting evidence of daytime and nighttime warming since the 1940s until 2005 is presented. The exception is the dry season which is dominated by daytime cooling attributable to the damping effect of dust haze/storms. Apparently, the progressive drought across inland locations has raised the MAXs, and to a lesser extent the MINs, of the wet season over those for the hot season. Accordingly, maximum rates of 0.451 and 0.336 degrees C decade(-1) were found for the nighttime and daytime temperatures, respectively. The extreme eastern and western locations have been frequently dominated by the warmest trend rates obtained nationwide. The prevalence of significant decreases (increases) of DTR is more apparent in the dry, hot and annual series (wet series). Depending on the temperature variable under consideration, many stations possessed significant trends toward either increased or decreased variability of the within-year monthly values, i.e. IAV. The correlation between the time series of annual CV and extreme values for each of the four temperature variables shows generally that warmer climate in Sudan is associated with higher intra-annual temperature variability and vise versa, i.e. the CV is directly correlated with the highest value within the year, but inversely correlated with the lowest one. The findings of this investigation also indicate that the DTR is directly related to percent of possible sunshine, but the relationship of the latter parameter is not so clear with MAX, MIN and MEAN. PMID:21053725

  4. Effect of production microclimate on female thermal state with increased temperature and air humidity

    NASA Technical Reports Server (NTRS)

    Machablishvili, O. G.

    1980-01-01

    The thermal state of women during the effect of high air temperature and relative humidity with a varying degree of physical loads was studied. Parameters for air temperature, relative humidity, and air movement were established. It was established that in women the thermo-regulatory stress occurs at lower air temperatures and with lower physical loads than in men. The accumulation of heat in women was revealed with lower air temperature than in men. It is concluded that to preserve the normal physiological state of the female organism it is necessary to create more favorable microclimate conditions and decrease the physical loads.

  5. Estimating Air Temperature over the Tibetan Plateau Using MODIS Data

    NASA Astrophysics Data System (ADS)

    Huang, Fangfang; Ma, Weiqiang; Ma, Yaoming; Li, Maoshan; Hu, Zeyong

    2016-04-01

    Time series of MODIS land surface temperature (LST) data and normalized difference vegetation index (NDVI) data, combined with digital elevation model (DEM) and meterological data for 2001-2012, were used to estimate and map the spatial distribution of monthly mean air temperature over the Tibatan Plateau (TP). Time series and regression analysis of monthly mean land surface temperature (Ts) and air temperature (Ta) were both conducted by ordinary liner regression (OLR) and geographical weighted regression (GWR) methods. Analysis showed that GWR method had much better result (Adjusted R2 > 0.79, root mean square error (RMSE) is between 0.51° C and 1.12° C) for estimating Ta than OLR method. The GWR model, with MODIS LST, NDVI and altitude as independent variables, was used to estimate Ta over the Tibetan Plateau. All GWR models in each month were tested by F-test with significant level of α=0.01 and the regression coefficients were all tested by T-test with significant level of α=0.01. This illustrated that Ts, NDVI and altitude play an important role on estimating Ta over the Tibetan Plateau. Finally, the major conclusions are as follows: (1) GWR method has higher accuracy for estimating Ta than OLR (Adjusted R2=0.40˜0.78, RMSE=1.60˜4.38° C), and the Ta control precision can be up to 1.12° C. (2) Over the Northern TP, the range of Ta variation in January is -29.28 ˜ -5.0° C, and that in July is -0.53 ˜ 14.0° C. Ta in summer half year (from May to October) is between -15.92 ˜ 14.0° C. From October on, 0° C isothermal level is gradually declining from the altitude of 4˜5 kilometers, and hits the bottom with altitude of 3200 meters in December, and Ta is all under 0° C in January. 10° C isothermal level gradually starts rising from the altitude of 3200 meters from May, and reaches the highest level with altitude of 4˜5 kilometers in July. In addition, Ta in south slope of the Tanggula Mountains is obviously higher than that in the north slope. Ta

  6. Using Field-Metered Data to Quantify Annual Energy Use of Portable Air Conditioners

    SciTech Connect

    Burke, Thomas; Willem, Henry; Ni, Chun Chun; Stratton, Hannah; Chen, Yuting; Ganeshalingam, Mohan; Iyer, Maithili; Price, Sarah; Dunham, Camilla

    2014-12-01

    As many regions of the United States experience rising temperatures, consumers have come to rely increasingly on cooling appliances (including portable air conditioners) to provide a comfortable indoor temperature. Home occupants sometimes use a portable air conditioner (PAC) to maintain a desired indoor temperature in a single room or enclosed space. Although PACs in residential use are few compared to centrally installed and room air conditioning (AC) units, the past few years have witnessed an increase of PACs use throughout the United States. There is, however, little information and few research projects focused on the energy consumption and performance of PACs, particularly studies that collect information from field applications of PACs. The operation and energy consumption of PACs may differ among geographic locations and households, because of variations in cooling load, frequency, duration of use, and other user-selected settings. In addition, the performance of building envelope (thermal mass and air leakage) as well as inter-zonal mixing within the building would substantially influence the ability to control and maintain desirable indoor thermal conditions. Lawrence Berkeley National Laboratory (LBNL) conducted an initial field-metering study aimed at increasing the knowledge and data related to PAC operation and energy consumption in the United States.

  7. Impact of aerosol on air temperature in Kuwait

    NASA Astrophysics Data System (ADS)

    Sabbah, I.

    2010-08-01

    This work uses MODIS aerosol optical thickness (AOT) data observed over Kuwait during the 7-year interval 2000-2007. The values of AOT and the Ångström wavelength exponent ( α) show a clear annual cycle. These data are categorized into two catalogues in terms of the values of the AOT of the 870 nm channel ( τ870). One catalogue (71 days) includes days with high values of AOT ( τ870 ≥ 0.75). The most probable "modal" value of α for these days is 0.52. The other catalogue (1162 days) consists of the background days with a modal value ~ 1.1 for the exponent α. This analysis is extended to include water vapor content (WVC), surface wind speed (V), visibility (Vis) and the diurnal temperature range (DTR). Chree's method of superposed-epoch analysis is applied to these parameters in order to compare the variation in the daily averages during days with high AOT values with respect to background days. The high values of AOT during the 71 days are positively correlated with aerosol size, near-surface winds and poor visibility. This concludes that the aerosol particles during these days were mostly dust. The mean daily value of the DTR (Δ T) and visibility reduced significantly during these days. This reduction on DTR is a direct result of increasing the atmospheric opacity due to the presence of dust.

  8. Seasonal variation of air temperature at the Mendel Station, James Ross Island in the period of 2006-2009

    NASA Astrophysics Data System (ADS)

    Laska, Kamil; Prošek, Pavel; Budík, Ladislav

    2010-05-01

    Key words: air temperature, seasonal variation, James Ross Island, Antarctic Peninsula Recently, significant role of the atmospheric and oceanic circulation variation on positive trend of near surface air temperature along the Antarctic Peninsula has been reported by many authors. However, small number of the permanent meteorological stations located on the Peninsula coast embarrasses a detail analysis. It comprises analysis of spatiotemporal variability of climatic conditions and validation of regional atmospheric climate models. However, geographical location of the Czech Johann Gregor Mendel Station (hereafter Mendel Station) newly established on the northern ice-free part of the James Ross Island provides an opportunity to fill the gap. There are recorded important meteorological characteristics which allow to evaluate specific climatic regime of the region and their impact on the ice-shelf disintegration and glacier retreat. Mendel Station (63°48'S, 57°53'W) is located on marine terrace at the altitude of 7 m. In 2006, a monitoring network of several automatic weather stations was installed at different altitudes ranging from the seashore level up to mesas and tops of glaciers (514 m a.s.l.). In this contribution, a seasonal variation of near surface air temperature at the Mendel Station in the period of 2006-2009 is presented. Annual mean air temperature was -7.2 °C. Seasonal mean temperature ranged from +1.4 °C (December-February) to -17.7 °C (June-August). Frequently, the highest temperature occurred in the second half of January. It reached maximum of +8.1 °C. Sudden changes of atmospheric circulation pattern during winter caused a large interdiurnal variability of air temperature with the amplitude of 30 °C.

  9. Topographic and spatial impacts of temperature inversions on air quality using mobile air pollution surveys.

    PubMed

    Wallace, Julie; Corr, Denis; Kanaroglou, Pavlos

    2010-10-01

    We investigated the spatial and topographic effects of temperature inversions on air quality in the industrial city of Hamilton, located at the western tip of Lake Ontario, Canada. The city is divided by a 90-m high topographic scarp, the Niagara Escarpment, and dissected by valleys which open towards Lake Ontario. Temperature inversions occur frequently in the cooler seasons, exacerbating the impact of emissions from industry and traffic. This study used pollution data gathered from mobile monitoring surveys conducted over a 3-year period, to investigate whether the effects of the inversions varied across the city. Temperature inversions were identified with vertical temperature data from a meteorological tower located within the study area. We divided the study area into an upper and lower zone separated by the Escarpment and further into six zones, based on location with respect to the Escarpment and industrial and residential areas, to explore variations across the city. The results identified clear differences in the responses of nitrogen dioxide (NO(2)) and fine particulate matter (PM2.5) to temperature inversions, based on the topographic and spatial criteria. We found that pollution levels increased as the inversion strengthened, in the lower city. However, the results also suggested that temperature inversions identified in the lower city were not necessarily experienced in the upper city with the same intensity. Further, pollution levels in the upper city appeared to decrease as the inversion deepened in the lower city, probably because of an associated change in prevailing wind direction and lower wind speeds, leading to decreased long-range transport of pollutants. PMID:20705328

  10. Proceedings of the Air & Waste Management Association's (A & WMA) 100th annual conference and exhibition

    SciTech Connect

    2007-07-01

    The CD-ROM contains more than 500 full technical presentations from the Air and Waste Management Association's 100th Annual Conference. The 2007 Critical Review 'Will the circle be unbroken? A history of the US national ambient air quality standards' is also included, as well as articles celebrating A & WMA's centennial. Subjects covered include: PM field studies; fine particles; PM measurements; chemical composition of the atmosphere; photochemical process in the atmosphere; short range dispersion; regional model analysis; long range dispersion modeling; noises and vibration; visibility; indoor air quality chemistry and physics; SO{sub 3} and SO{sub 2} control techniques; NOx control; mercury and power generation, technology and control; mercury emissions control, measurement and science; PM2.5 fine particle emission control; CO{sub 2} capture from combustion sources; innovations in control of VOCs and other hazardous emissions; organic vapor capture for recovery, recycling or destruction; biological control of emissions; computer generated inventories; ambient monitoring field studies; satellite remote sensing; MACT developments; particulate matter; environmental compliance at Federal facilities; mercury monitoring in the power generation industry; coal plant and IGCC regulatory and permitting issues; environmental issues facing industry energy; climate change electric power industry perspectives; and climate change and sustainability shortages.

  11. A simple-harmonic model for depicting the annual cycle of seasonal temperatures of streams

    USGS Publications Warehouse

    Steele, Timothy Doak

    1978-01-01

    Due to economic or operational constraints, stream-temperature records cannot always be collected at all sites where information is desired or at frequencies dictated by continuous or near-continuous surveillance requirements. For streams where only periodic measurements are made during the year, and that are not appreciably affected by regulation or by thermal loading , a simple harmonic function may adequately depict the annual seasonal cycle of stream temperature at any given site. Resultant harmonic coefficients obtained from available stream-temperature records may be used in the following ways: (1) To interpolate between discrete measurements by solving the harmonic function at specified times, thereby filling in estimates of stream-temperature values; (2) to characterize areal or regional patterns of natural stream-temperature values; (2) to characterize areal or regional patterns of natural stream-temperature conditions; and (3) to detect and to assess any significant at a site brought about by streamflow regulation or basin development. Moreover, less-than-daily or sampling frequencies at a given site may give estimates of annual variation of stream temperatures that are statistically comparable to estimates obtained from a daily or continuous sampling scheme. The latter procedure may result in potential savings of resources in network operations, with negligible loss in information on annual stream-temperature variations. (Woodard -USGS)

  12. Combustion and gasification characteristics of pulverized coal using high-temperature air

    SciTech Connect

    Hanaoka, R.; Nakamura, M.; Kiga, T.; Kosaka, H.; Iwahashi, T.; Yoshikawa, K.; Sakai, M.; Muramatsu, K.; Mochida, S.

    1998-07-01

    In order to confirm performance of high-temperature-air combusting of pulverized coal, laboratory-scale combustion and gasification tests of coal were conducted changing air temperature and oxygen concentration in the air. Theses were conducted in a drop tube furnace of 200mm in inside diameter and 2,000mm in length. The furnace was heated by ceramic heater up to 1,300 C. A high-temperature air preheater utilizing the HRS (High Cycle Regenerative Combustion System) was used to obtain high-temperature combustion air. As the results, NOx emission was reduced when pulverized coal was fired with high-temperature-air. On the other hand, by lower oxygen concentration in combustion air diluted by nitrogen, NOx emission slightly decreased while became higher under staging condition.

  13. How the Plant Temperature Links to the Air Temperature in the Desert Plant Artemisia ordosica

    PubMed Central

    Yu, Ming-Han; Ding, Guo-Dong; Gao, Guang-Lei; Sun, Bao-Ping; Zhao, Yuan-Yuan; Wan, Li; Wang, De-Ying; Gui, Zi-Yang

    2015-01-01

    Plant temperature (Tp) is an important indicator of plant health. To determine the dynamics of plant temperature and self-cooling ability of the plant, we measured Tp in Artemisia ordosica in July, in the Mu Us Desert of Northwest China. Related factors were also monitored to investigate their effects on Tp, including environmental factors, such as air temperature (Ta), relative humidity, wind speed; and physiological factors, such as leaf water potential, sap flow, and water content. The results indicate that: 1) Tp generally changes in conjunction with Ta mainly, and varies with height and among the plant organs. Tp in the young branches is most constant, while it is the most sensitive in the leaves. 2) Correlations between Tp and environmental factors show that Tp is affected mainly by Ta. 3) The self-cooling ability of the plant was effective by midday, with Tp being lower than Ta. 4) Increasing sap flow and leaf water potential showed that transpiration formed part of the mechanism that supported self-cooling. Increased in water conductance and specific heat at midday may be additional factors that contribute to plant cooling ability. Therefore, our results confirmed plant self-cooling ability. The response to high temperatures is regulated by both transpiration speed and an increase in stem water conductance. This study provides quantitative data for plant management in terms of temperature control. Moreover, our findings will assist species selection with taking plant temperature as an index. PMID:26280557

  14. Environmentally sound thermal energy extraction from coal and wastes using high temperature air combustion technology

    SciTech Connect

    Yoshikawa, Kunio

    1999-07-01

    High temperature air combustion is one of promising ways of burning relatively low BTU gas obtained from gasification of low grade coal or wastes. In this report, the author proposes a new power generation system coupled with high temperature air gasification of coal/wastes and high temperature air combustion of the syngas from coal/wastes. This system is realized by employing Multi-staged Enthalpy Extraction Technology (MEET). The basic idea of the MEET system is that coal or wastes are gasified with high temperature air of about 1,000 C, then the generated syngas is cooled in a heat recovery boiler to be cleaned-up in a gas cleanup system (desulfurization, desalinization and dust removal). Part of thermal energy contained in this cleaned-up syngas is used for high temperature air preheating, and the complete combustion of the fuel gas is done using also high temperature air for driving gas turbines or steam generation in a boiler.

  15. Analysis of spanwise temperature distribution in three types of air-cooled turbine blade

    NASA Technical Reports Server (NTRS)

    Livingood, John N B; Brown, W Byron

    1950-01-01

    Methods for computing spanwise blade-temperature distributions are derived for air-cooled hollow blades, air-cooled hollow blades with inserts, and air-cooled blades containing internal cooling fins. Individual and combined effects on spanwise blade-temperature distributions of cooling-air and radial heat conduction are determined. In general, the effects of radiation and radial heat conduction were found to be small and the omission of these variations permitted the construction of nondimensional charts for use in determining spanwise temperature distribution through air-cooled turbine blades. An approximate method for determining the allowable stress-limited blade-temperature distribution is included, with brief accounts of a method for determining the maximum allowable effective gas temperatures and the cooling-air requirements. Numerical examples that illustrate the use of the various temperature-distribution equations and of the nondimensional charts are also included.

  16. Temporal and spatial assessments of minimum air temperature using satellite surface temperature measurements in Massachusetts, USA

    PubMed Central

    Kloog, Itai; Chudnovsky, Alexandra; Koutrakis, Petros; Schwartz, Joel

    2015-01-01

    Although meteorological stations provide accurate air temperature observations, their spatial coverage is limited and thus often insufficient for epidemiological studies. Satellite data expand spatial coverage, enhancing our ability to estimate near surface air temperature (Ta). However, the derivation of Ta from surface temperature (Ts) measured by satellites is far from being straightforward. In this study, we present a novel approach that incorporates land use regression, meteorological variables and spatial smoothing to first calibrate between Ts and Ta on a daily basis and then predict Ta for days when satellite Ts data were not available. We applied mixed regression models with daily random slopes to calibrate Moderate Resolution Imaging Spectroradiometer (MODIS) Ts data with monitored Ta measurements for 2003. Then, we used a generalized additive mixed model with spatial smoothing to estimate Ta in days with missing Ts. Out-of-sample tenfold cross-validation was used to quantify the accuracy of our predictions. Our model performance was excellent for both days with available Ts and days without Ts observations (mean out-of-sample R2=0.946 and R2=0.941 respectively). Furthermore, based on the high quality predictions we investigated the spatial patterns of Ta within the study domain as they relate to urban vs. non-urban land uses. PMID:22721687

  17. Spectroscopic diagnostics of high temperature plasmas. [Annual report

    SciTech Connect

    Moos, W.

    1990-12-31

    A three-year research program for the development of novel XUV spectroscopic diagnostics for magnetically confined fusion plasmas is proposed. The new diagnostic system will use layered synthetic microstructures (LSM) coated, flat and curved surfaces as dispersive elements in spectrometers and narrow band XUV filter arrays. In the framework of the proposed program we will develop impurity monitors for poloidal and toroidal resolved measurements on PBX-M and Alcator C-Mod, imaging XUV spectrometers for electron density and temperature fluctuation measurements in the hot plasma core in TEXT or other similar tokamaks and plasma imaging devices in soft x-ray light for impurity behavior studies during RF heating on Phaedrus T and carbon pellet ablation in Alcator C-Mod. Recent results related to use of multilayer in XUV plasma spectroscopy are presented. We also discuss the latest results reviewed to q{sub o} and local poloidal field measurements using Zeeman polarimetry.

  18. Seasonal and inter-annual variability of lower stratospheric age of air spectra

    NASA Astrophysics Data System (ADS)

    Ploeger, Felix; Birner, Thomas

    2016-08-01

    Trace gas transport in the lower stratosphere is investigated by analysing seasonal and inter-annual variations of the age of air spectrum - the probability distribution of stratospheric transit times. Age spectra are obtained using the Chemical Lagrangian Model of the Stratosphere (CLaMS) driven by ERA-Interim winds and total diabatic heating rates, and using a time-evolving boundary-impulse-response (BIER) method based on multiple tracer pulses. Seasonal age spectra show large deviations from an idealized stationary uni-modal shape. Multiple modes emerge in the spectrum throughout the stratosphere, strongest at high latitudes, caused by the interplay of seasonally varying tropical upward mass flux, stratospheric transport barriers and recirculation. Inter-annual variations in transport (e.g. quasi-biennial oscillation) cause significant modulations of the age spectrum shape. In fact, one particular QBO phase may determine the spectrum's mode during the following 2-3 years. Interpretation of the age spectrum in terms of transport contributions due to the residual circulation and mixing is generally not straightforward. It turns out that advection by the residual circulation represents the dominant pathway in the deep tropics and in the winter hemisphere extratropics above 500 K, controlling the modal age in these regions. In contrast, in the summer hemisphere, particularly in the lowermost stratosphere, mixing represents the most probable pathway controlling the modal age.

  19. Compression-ignition Engine Performance at Altitudes and at Various Air Pressures and Temperatures

    NASA Technical Reports Server (NTRS)

    Moore, Charles S; Collins, John H

    1937-01-01

    Engine test results are presented for simulated altitude conditions. A displaced-piston combustion chamber on a 5- by 7-inch single cylinder compression-ignition engine operating at 2,000 r.p.m. was used. Inlet air temperature equivalent to standard altitudes up to 14,000 feet were obtained. Comparison between performance at altitude of the unsupercharged compression-ignition engine compared favorably with the carburetor engine. Analysis of the results for which the inlet air temperature, inlet air pressure, and inlet and exhaust pressure were varied indicates that engine performance cannot be reliably corrected on the basis of inlet air density or weight of air charge. Engine power increases with inlet air pressure and decreases with inlet air temperatures very nearly as straight line relations over a wide range of air-fuel ratios. Correction factors are given.

  20. Apparatus for supplying conditioned air at a substantially constant temperature and humidity

    NASA Technical Reports Server (NTRS)

    Obler, H. D. (Inventor)

    1980-01-01

    The apparatus includes a supply duct coupled to a source of supply air for carrying the supply air therethrough. A return duct is coupled to the supply duct for carrying return conditioned air therethrough. A temperature reducing device is coupled to the supply duct for decreasing the temperature of the supply and return conditioned air. A by-pass duct is coupled to the supply duct for selectively directing portions of the supply and return conditioned air around the temperature reducing device. Another by-pass duct is coupled to the return duct for selectively directing portions of the return conditioned air around the supply duct and the temperature reduction device. Controller devices selectively control the flow and amount of mixing of the supply and return conditioned air.

  1. Time scales of the European surface air temperature variability: The role of the 7-8 year cycle

    NASA Astrophysics Data System (ADS)

    Jajcay, Nikola; Hlinka, Jaroslav; Kravtsov, Sergey; Tsonis, Anastasios A.; Paluš, Milan

    2016-01-01

    Air temperature variability on different time scales exhibits recurring patterns and quasi-oscillatory phenomena. Climate oscillations with the period about 7-8 years have been observed in many instrumental records in Europe. Although these oscillations are weak if considering their amplitude, they might have nonnegligible influence on temperature variability on shorter time scales due to cross-scale interactions recently observed by Paluš (2014). In order to quantify the cross-scale influence, we propose a simple conditional mean approach which estimates the effect of the cycle with the period close to 8 years on the amplitude of the annual cycle in surface air temperature (SAT) in the range 0.7-1.4°C and the effect on the overall variability of the SAT anomalies (SATA) leads to the changes 1.5-1.7°C in the annual SATA means. The strongest effect in the winter SATA means reaches 4-5°C in central European station and reanalysis data.

  2. The annual cycle of temperature in the Sahel and its climatic sensitivity

    NASA Astrophysics Data System (ADS)

    Guichard, F.; Kergoat, L.; Mougin, E.; Hourdin, F.

    2012-12-01

    In the subtropical semi-arid Sahel, a major climatic feature is the bimodal structure of the annual cycle of temperature at the surface, with two maxima surrounding the rainy season. The first one, in Spring, is particularly large in the Sahel, with monthly mean temperature reaching 35°C at 15°N. The goal of this study is to analyse (i) the thermodynamic couplings associated with this specific structure and to assess how the multi-decadal warming observed in this region has affected the structure of the annual cycle of temperature. We use several observational datasets including (i) local meteorological data (SYNOP, GISS, BEST, Hombori historical data) and the CRU and MSU gridded datasets, which all cover several decades, and (ii) high-frequency AMMA-Catch ground station data available over the last decade. The latter allow exploring couplings between temperature, water and surface energy budget. These datasets are further used to evaluate several reanalyses (ERA Interim, NCEP CFSR, MERRA and climate models (CMIP5 simulations). The observational datasets indicate that a strong increase of temperature, on the order of 1K or more, has occurred in Spring (April-May) in the Sahel over the past 60 years, with larger values at night. They further show that in Spring, the short-term inter-annual variability (less than 10 years) is the weakest, while on the other hand, the multi-decennal trend is the more pronounced. The processes associated with the increase of temperature in Spring are radically different from those accounting for temperature trends observed during the rainy season (The latter involves couplings between rainfall and temperature, with more rainfall associated with lower temperature.) Furthermore, a strong warming in Spring, as temperature is already at its annual maximum, is likely to have particularly strong societal implications. . Overall, reanalyses qualitatively reproduce the observed changes. However, the results are affected by discontinuities

  3. Examination of the Armagh Observatory Annual Mean Temperature Record, 1844-2004

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2006-01-01

    The long-term annual mean temperature record (1844-2004) of the Armagh Observatory (Armagh, Northern Ireland, United Kingdom) is examined for evidence of systematic variation, in particular, as related to solar/geomagnetic forcing and secular variation. Indeed, both are apparent in the temperature record. Moving averages for 10 years of temperature are found to highly correlate against both 10-year moving averages of the aa-geomagnetic index and sunspot number, having correlation coefficients of approx. 0.7, inferring that nearly half the variance in the 10-year moving average of temperature can be explained by solar/geomagnetic forcing. The residuals appear episodic in nature, with cooling seen in the 1880s and again near 1980. Seven of the last 10 years of the temperature record has exceeded 10 C, unprecedented in the overall record. Variation of sunspot cyclic averages and 2-cycle moving averages of temperature strongly associate with similar averages for the solar/geomagnetic cycle, with the residuals displaying an apparent 9-cycle variation and a steep rise in temperature associated with cycle 23. Hale cycle averages of temperature for even-odd pairs of sunspot cycles correlate against similar averages for the solar/geomagnetic cycle and, especially, against the length of the Hale cycle. Indications are that annual mean temperature will likely exceed 10 C over the next decade.

  4. Annual cycles of organochlorine pesticide enantiomers in Arctic air suggest changing sources and pathways

    NASA Astrophysics Data System (ADS)

    Bidleman, T. F.; Jantunen, L. M.; Hung, H.; Ma, J.; Stern, G. A.; Rosenberg, B.; Racine, J.

    2015-02-01

    Air samples collected during 1994-2000 at the Canadian Arctic air monitoring station Alert (82°30' N, 62°20' W) were analysed by enantiospecific gas chromatography-mass spectrometry for α-hexachlorocyclohexane (α-HCH), trans-chlordane (TC) and cis-chlordane (CC). Results were expressed as enantiomer fractions (EF = peak areas of (+)/[(+) + (-)] enantiomers), where EFs = 0.5, < 0.5 and > 0.5 indicate racemic composition, and preferential depletion of (+) and (-) enantiomers, respectively. Long-term average EFs were close to racemic values for α -HCH (0.504 ± 0.004, n = 197) and CC (0.505 ± 0.004, n = 162), and deviated farther from racemic for TC (0.470 ± 0.013, n = 165). Digital filtration analysis revealed annual cycles of lower α-HCH EFs in summer-fall and higher EFs in winter-spring. These cycles suggest volatilization of partially degraded α-HCH with EF < 0.5 from open water and advection to Alert during the warm season, and background transport of α-HCH with EF > 0.5 during the cold season. The contribution of sea-volatilized α-HCH was only 11% at Alert, vs. 32% at Resolute Bay (74.68° N, 94.90° W) in 1999. EFs of TC also followed annual cycles of lower and higher values in the warm and cold seasons. These were in phase with low and high cycles of the TC/CC ratio (expressed as FTC = TC/(TC+CC)), which suggests greater contribution of microbially "weathered" TC in summer-fall versus winter-spring. CC was closer to racemic than TC and displayed seasonal cycles only in 1997-1998. EF profiles are likely to change with rising contribution of secondary emission sources, weathering of residues in the environment, and loss of ice cover in the Arctic. Enantiomer-specific analysis could provide added forensic capability to air monitoring programs.

  5. 77 FR 39169 - Eighth Coast Guard District Annual Safety Zones; Blue Angels Air Show; Gulf of Mexico & Santa...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Eighth Coast Guard District Annual Safety Zones; Blue Angels Air Show; Gulf of Mexico & Santa Rosa Sound; Pensacola, FL AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce a Safety Zone for the...

  6. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for Release to Sewerage B Appendix B to Part 20 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Pt. 20, App. B Appendix...

  7. 10 CFR Appendix B to Part 20 - Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for Release to Sewerage B Appendix B to Part 20 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Pt. 20, App. B Appendix...

  8. Environmental Scanning Activities in Higher Education as Reported at the 1986 Annual Meetings of AAHE, AIR, and SCUP.

    ERIC Educational Resources Information Center

    Morrison, James L.

    Environmental scanning activities in higher education were described in forums at the 1986 annual meetings of the American Association for Higher Education (AAHE), the Association for Institutional Research (AIR), and the Society of College and University Planning (SCUP). The forums were held to determine the extent of environmental scanning…

  9. Short-term effects of air temperature on plasma metabolite concentrations in patients undergoing cardiac cattheterization.

    EPA Science Inventory

    BACKGROUND: Epidemiological studies have shown associations between air temperature and cardiovascular health outcomes. Metabolic dysregulation might also play a role in the development of cardiovascular disease.OBJECTIVES: To investigate short-term temperature effects on metabol...

  10. Startup of air-cooled condensers and dry cooling towers at low temperatures of the cooling air

    NASA Astrophysics Data System (ADS)

    Milman, O. O.; Ptakhin, A. V.; Kondratev, A. V.; Shifrin, B. A.; Yankov, G. G.

    2016-05-01

    The problems of startup and performance of air-cooled condensers (ACC) and dry cooling towers (DCT) at low cooling air temperatures are considered. Effects of the startup of the ACC at sub-zero temperatures are described. Different options of the ACC heating up are analyzed, and examples of existing technologies are presented (electric heating, heating up with hot air or steam, and internal and external heating). The use of additional heat exchanging sections, steam tracers, in the DCT design is described. The need for high power in cases of electric heating and heating up with hot air is noted. An experimental stand for research and testing of the ACC startup at low temperatures is described. The design of the three-pass ACC unit is given, and its advantages over classical single-pass design at low temperatures are listed. The formation of ice plugs inside the heat exchanging tubes during the start-up of ACC and DCT at low cooling air temperatures is analyzed. Experimental data on the effect of the steam flow rate, steam nozzle distance from the heat-exchange surface, and their orientation in space on the metal temperature were collected, and test results are analyzed. It is noted that the surface temperature at the end of the heat up is almost independent from its initial temperature. Recommendations for the safe start-up of ACCs and DCTs are given. The heating flow necessary to sufficiently heat up heat-exchange surfaces of ACCs and DCTs for the safe startup is estimated. The technology and the process of the heat up of the ACC with the heating steam external supply are described by the example of the startup of the full-scale section of the ACC at sub-zero temperatures of the cooling air, and the advantages of the proposed start-up technology are confirmed.

  11. Twenty Years of High-Resolution Sea Surface Temperature Imagery around Australia: Inter-Annual and Annual Variability

    PubMed Central

    Foster, Scott D.; Griffin, David A.; Dunstan, Piers K.

    2014-01-01

    The physical climate defines a significant portion of the habitats in which biological communities and species reside. It is important to quantify these environmental conditions, and how they have changed, as this will inform future efforts to study many natural systems. In this article, we present the results of a statistical summary of the variability in sea surface temperature (SST) time-series data for the waters surrounding Australia, from 1993 to 2013. We partition variation in the SST series into annual trends, inter-annual trends, and a number of components of random variation. We utilise satellite data and validate the statistical summary from these data to summaries of data from long-term monitoring stations and from the global drifter program. The spatially dense results, available as maps from the Australian Oceanographic Data Network's data portal (http://www.cmar.csiro.au/geonetwork/srv/en/metadata.show?id=51805), show clear trends that associate with oceanographic features. Noteworthy oceanographic features include: average warming was greatest off southern West Australia and off eastern Tasmania, where the warming was around 0.6°C per decade for a twenty year study period, and insubstantial warming in areas dominated by the East Australian Current, but this area did exhibit high levels of inter-annual variability (long-term trend increases and decreases but does not increase on average). The results of the analyses can be directly incorporated into (biogeographic) models that explain variation in biological data where both biological and environmental data are on a fine scale. PMID:24988444

  12. One-Component Pressure-Temperature Phase Diagrams in the Presence of Air

    ERIC Educational Resources Information Center

    Andrade-Gamboa, Julio; Martire, Daniel O.; Donati, Edgardo R.

    2010-01-01

    One-component phase diagrams are good approximations to predict pressure-temperature ("P-T") behavior of a substance in the presence of air, provided air pressure is not much higher than the vapor pressure. However, at any air pressure, and from the conceptual point of view, the use of a traditional "P-T" phase diagram is not strictly correct. In…

  13. 40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.670 NOX intake-air humidity and temperature corrections. See the standard-setting part to determine if you... 40 Protection of Environment 34 2013-07-01 2013-07-01 false NOX intake-air humidity...

  14. 40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.670 NOX intake-air humidity and temperature corrections. See the standard-setting part to determine if you... 40 Protection of Environment 33 2011-07-01 2011-07-01 false NOX intake-air humidity...

  15. 40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.670 NOX intake-air humidity and temperature corrections. See the standard-setting part to determine if you... 40 Protection of Environment 32 2010-07-01 2010-07-01 false NOX intake-air humidity...

  16. 40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.670 NOX intake-air humidity and temperature corrections. See the standard-setting part to determine if you... 40 Protection of Environment 34 2012-07-01 2012-07-01 false NOX intake-air humidity...

  17. 40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.670 NOX intake-air humidity and temperature corrections. See the standard-setting part to determine if you... 40 Protection of Environment 33 2014-07-01 2014-07-01 false NOX intake-air humidity...

  18. The impact of heterogeneous surface temperatures on the 2-m air temperature over the Arctic Ocean in spring

    NASA Astrophysics Data System (ADS)

    Tetzlaff, A.; Kaleschke, L.; Lüpkes, C.; Ament, F.; Vihma, T.

    2012-07-01

    The influence of spatial surface temperature changes over the Arctic Ocean on the 2-m air temperature variability is estimated using backward trajectories based on ERA-Interim and the JRA25 wind fields. They are initiated at Alert, Barrow and at the Tara drifting station. Three different methods are used. The first one compares mean ice surface temperatures along the trajectories to the observed 2-m air temperatures at the stations. The second one correlates the observed temperatures to air temperatures obtained using a simple Lagrangian box model which only includes the effect of sensible heat fluxes. For the third method, mean sensible heat fluxes from the model are correlated with the difference of the air temperatures at the model starting point and the observed temperatures at the stations. The calculations are based on MODIS ice surface temperatures and four different sets of ice concentration derived from SSM/I and AMSR-E data. Under nearly cloud free conditions, up to 90% of the 2-m air temperature variance can be explained for Alert, and 60% for Barrow using these methods. The differences are attributed to the different ice conditions, which are characterized by high ice concentration around Alert and lower ice concentration near Barrow. These results are robust for the different sets of reanalyses and ice concentration data. Near-surface winds of both reanalyses show a large inconsistency in the Central Arctic, which leads to a large difference in the correlations between modeled and observed 2-m air temperatures at Tara. Explained variances amount to 70% using JRA and only 45% using ERA. The results also suggest that near-surface temperatures at a given site are influenced by the variability of surface temperatures in a domain of about 150 to 350 km radius around the site.

  19. Inter-comparison of upper air temperature over China between Radiosonde and Reanalysis Data

    NASA Astrophysics Data System (ADS)

    Guo, Yanjun; Zhang, Siqi; Yan, Jinghui; Chen, Zhe; Ruan, Xin

    2016-04-01

    Based on quality controlled(RAW) and homogenized(ADJ) radiosonde temperatures at 850-30hPa from 118 stations in China and monthly mean temperatures from eight reanalysis datasets(REA) which included NCEPv1, NCEPv2, ERA-40, ERA-Interim, JRA55, 20CR, MERRA and CFSR, a preliminary comparison of upper air temperatures over China between radiosonde and reanalysis was undertaken. The mean difference, correlation, standard deviation and linear trend between RAW and ADJ, REA and RAW, REA and ADJ during 1981-2010 were analyzed and results demonstrated ADJ temperatures averaged in China were generally cooler than RAW and the negative adjustments were the most significant at the upper troposphere and the lower stratosphere. Homogenization removed the system error caused by radiosonde instrument and observation system update from RAW. Hence the correlations between REA and ADJ were higher than those between REA and RAW. ADJ is more suitable than RAW as an evaluation index of reanalysis data. The mean difference between REA and ADJ were about 1C during 1981-2010, while REA were generally cooler than ADJ in the troposphere and warmer in the stratosphere. Significant correlations proved the consistence of annual variability between REA and ADJ. The linear trends are consistent between REA and ADJ with warming in the lower and middle troposphere and cooling in the middle stratosphere. More uncertainly were revealed at the upper troposphere and the lower stratosphere. ERA-Interim, JRA55 and MERRA were generally closer to ADJ than other reanalysis datasets.

  20. Fundamental air-gasification engineering parameters. Annual report for fiscal year 1981

    SciTech Connect

    Desrosiers, R.

    1982-02-01

    A mathematical simulation of an air-blown, updraft gasifier was used to study the effect of char reactivity, particle size, and steam rate on the temperture and composition profiles in the bed of reactor. The results are insensitive to the rate assumed for the reaction of char with oxygen since this reaction appears to be diffusion limited. For a dry air blast, the maximum temperature achieved is determined chiefly by the rate of the char-CO/sub 2/ reaction, which is a feed-dependent parameter. The rate of char combustion reaction is inversely proportional to D/sub p//sup 1/ /sup 6/, where D/sub p/ is the particle diameter, while the char-CO/sub 2/ and char-steam reactions are inversely proportional to D/sub p/. Since the maximum temperature is strongly dependent on any parameter which affects the balance of these two sets of reactions, the particle size is a very sensitive variable. The minimum overall bed length required for complete char conversion is found to vary quadratically with D/sub p/. In the range of 1000/sup 0/C, the temperature does not vary monotonically with steam rate as expected.

  1. Prototypical experiments relating to air oxidation of Zircaloy-4 at high temperatures

    NASA Astrophysics Data System (ADS)

    Steinbrück, Martin

    2009-08-01

    The mechanism of the reaction between Zircaloy-4 and air at temperatures from 800 to 1500 °C was studied. Air attack under prototypical conditions with air ingress during a hypothetic severe nuclear reactor accident was investigated. Oxidation in air and in air and nitrogen-containing atmospheres leads to a major degradation of the cladding material. The main mechanism is the formation of zirconium nitride and its re-oxidation. Pre-oxidation in steam prevents air attack as long as the oxide scale is intact. Under steam/oxygen starvation conditions, the oxide scale is reduced and significant external nitride formation takes place. When modeling air ingress in severe accident computer codes, parabolic correlations for oxidation in air may be applied only for high temperatures (>1400 °C) and for pre-oxidized cladding (⩾1100 °C). Under all other conditions, faster, rather linear reaction kinetics should be applied.

  2. Predicting seed cotton moisture content from changes in drying air temperature - second year

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A mathematical model was used to predict seed cotton moisture content in the overhead section of a cotton gin. The model took into account the temperature, mass flow, and specific heat of both the air and seed cotton. Air temperatures and mass flows were measured for a second year at a commercial g...

  3. Correction of Temperatures of Air-Cooled Engine Cylinders for Variation in Engine and Cooling Conditions

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Pinkel, Benjamin; Ellerbrock, Herman H , Jr

    1939-01-01

    Factors are obtained from semiempirical equations for correcting engine-cylinder temperatures for variation in important engine and cooling conditions. The variation of engine temperatures with atmospheric temperature is treated in detail, and correction factors are obtained for various flight and test conditions, such as climb at constant indicated air speed, level flight, ground running, take-off, constant speed of cooling air, and constant mass flow of cooling air. Seven conventional air-cooled engine cylinders enclosed in jackets and cooled by a blower were tested to determine the effect of cooling-air temperature and carburetor-air temperature on cylinder temperatures. The cooling air temperature was varied from approximately 80 degrees F. to 230 degrees F. and the carburetor-air temperature from approximately 40 degrees F. to 160 degrees F. Tests were made over a large range of engine speeds, brake mean effective pressures, and pressure drops across the cylinder. The correction factors obtained experimentally are compared with those obtained from the semiempirical equations and a fair agreement is noted.

  4. Effects of Outside Air Temperature on Movement of Phosphine Gas in Concrete Elevator Bins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies that measured the movement and concentration of phosphine gas in upright concrete bins over time indicated that fumigant movement was dictated by air currents, which in turn, were a function of the difference between the average grain temperature and the average outside air temperature durin...

  5. Prediction of air temperature in the aircraft cabin under different operational conditions

    NASA Astrophysics Data System (ADS)

    Volavý, F.; Fišer, J.; Nöske, I.

    2013-04-01

    This paper deals with the prediction of the air temperature in the aircraft cabin by means of Computational Fluid Dynamics. The simulations are performed on the CFD model which is based on geometry and cabin interior arrangement of the Flight Test Facility (FTF) located at Fraunhofer IBP, Germany. The experimental test flights under three different cabin temperatures were done in FTF and the various data were gathered during these flights. Air temperature in the cabin was measured on probes located near feet, torso and head of each passenger and also surface temperature and air temperature distributed from inlets were measured. The data were firstly analysed in order to obtain boundary conditions for cabin surfaces and inlets. Then the results of air temperature from the simulations were compared with measured data. The suitability and accuracy of the CFD approach for temperature prediction is discussed.

  6. Uncertainties of satellite-derived surface skin temperatures in the polar oceans: MODIS, AIRS/AMSU, and AIRS only

    NASA Astrophysics Data System (ADS)

    Kang, H.-J.; Yoo, J.-M.; Jeong, M.-J.; Won, Y.-I.

    2015-10-01

    Uncertainties in the satellite-derived surface skin temperature (SST) data in the polar oceans during two periods (16-24 April and 15-23 September) 2003-2014 were investigated and the three data sets were intercompared as follows: MODerate Resolution Imaging Spectroradiometer Ice Surface Temperature (MODIS IST), the SST of the Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A (AIRS/AMSU), and AIRS only. The AIRS only algorithm was developed in preparation for the degradation of the AMSU-A. MODIS IST was systematically warmer up to 1.65 K at the sea ice boundary and colder down to -2.04 K in the polar sea ice regions of both the Arctic and Antarctic than that of the AIRS/AMSU. This difference in the results could have been caused by the surface classification method. The spatial correlation coefficient of the AIRS only to the AIRS/AMSU (0.992-0.999) method was greater than that of the MODIS IST to the AIRS/AMSU (0.968-0.994). The SST of the AIRS only compared to that of the AIRS/AMSU had a bias of 0.168 K with a RMSE of 0.590 K over the Northern Hemisphere high latitudes and a bias of -0.109 K with a RMSE of 0.852 K over the Southern Hemisphere high latitudes. There was a systematic disagreement between the AIRS retrievals at the boundary of the sea ice, because the AIRS only algorithm utilized a less accurate GCM forecast over the seasonally varying frozen oceans than the microwave data. The three data sets (MODIS, AIRS/AMSU and AIRS only) showed significant warming rates (2.3 ± 1.7 ~ 2.8 ± 1.9 K decade-1) in the northern high regions (70-80° N) as expected from the ice-albedo feedback. The systematic temperature disagreement associated with surface type classification had an impact on the resulting temperature trends.

  7. Uncertainties of satellite-derived surface skin temperatures in the polar oceans: MODIS, AIRS/AMSU, and AIRS only

    NASA Astrophysics Data System (ADS)

    Kang, H.-J.; Yoo, J.-M.; Jeong, M.-J.; Won, Y.-I.

    2015-05-01

    Uncertainties in the satellite-derived Surface Skin Temperature (SST) data in the polar oceans during two periods (16-24 April and 15-23 September) of 2003-2014 were investigated and the three datasets were intercompared as follows: MODerate Resolution Imaging Spectroradiometer Ice Surface Temperature (MODIS IST), the SST of the Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A (AIRS/AMSU), and AIRS only. AIRS only algorithm was developed in preparation for the degradation of the AMSU-A. MODIS IST was systematically up to 1.65 K warmer at the sea ice boundary and up to 2.04 K colder in the polar sea ice regions of both the Arctic and Antarctic than that of the AIRS/AMSU. This difference in the results could have been caused by the surface classification method. The spatial correlation coefficient of the AIRS only to the AIRS/AMSU (0.992-0.999) method was greater than that of the MODIS IST to the AIRS/AMSU (0.968-0.994). The SST of the AIRS only compared to that of the AIRS/AMSU had a bias of 0.168 K with a RMSE of 0.590 K over the Northern Hemisphere high latitudes and a bias of -0.109 K with a RMSE of 0.852 K over the Southern Hemisphere high latitudes. There was a systematic disagreement between the AIRS retrievals at the boundary of the sea ice, because the AIRS only algorithm utilized a~less accurate GCM forecast over the seasonally-varying frozen oceans than the microwave data. The three datasets (MODIS, AIRS/AMSU and AIRS only) showed significant warming rates (2.3 ± 1.7 ~2.8 ± 1.9 K decade-1) in the northern high latitude regions (70-80° N) as expected from the ice-albedo feedback. The systematic temperature disagreement associated with surface type classification had an impact on the resulting temperature trends.

  8. Robust comparison of climate models with observations using blended land air and ocean sea surface temperatures

    NASA Astrophysics Data System (ADS)

    Cowtan, Kevin; Hausfather, Zeke; Hawkins, Ed; Jacobs, Peter; Mann, Michael E.; Miller, Sonya K.; Steinman, Byron A.; Stolpe, Martin B.; Way, Robert G.

    2015-08-01

    The level of agreement between climate model simulations and observed surface temperature change is a topic of scientific and policy concern. While the Earth system continues to accumulate energy due to anthropogenic and other radiative forcings, estimates of recent surface temperature evolution fall at the lower end of climate model projections. Global mean temperatures from climate model simulations are typically calculated using surface air temperatures, while the corresponding observations are based on a blend of air and sea surface temperatures. This work quantifies a systematic bias in model-observation comparisons arising from differential warming rates between sea surface temperatures and surface air temperatures over oceans. A further bias arises from the treatment of temperatures in regions where the sea ice boundary has changed. Applying the methodology of the HadCRUT4 record to climate model temperature fields accounts for 38% of the discrepancy in trend between models and observations over the period 1975-2014.

  9. Modeling subcanopy incoming longwave radiation to seasonal snow using air and tree trunk temperatures

    NASA Astrophysics Data System (ADS)

    Webster, Clare; Rutter, Nick; Zahner, Franziska; Jonas, Tobias

    2016-02-01

    Data collected at three Swiss alpine forested sites over a combined 11 year period were used to evaluate the role of air temperature in modeling subcanopy incoming longwave radiation to the snow surface. Simulated subcanopy incoming longwave radiation is traditionally partitioned into that from the sky and that from the canopy, i.e., a two-part model. Initial uncertainties in predicting longwave radiation using the two-part model resulted from vertical differences in measured air temperature. Above-canopy (35 m) air temperatures were higher than those within (10 m) and below (2 m) canopy throughout four snow seasons (December-April), demonstrating how the forest canopy can act as a cold sink for air. Lowest model root-mean-square error (RMSE) was using above-canopy air temperature. Further investigation of modeling subcanopy longwave radiation using above-canopy air temperature showed underestimations, particularly during periods of high insolation. In order to explicitly account for canopy temperatures in modeling longwave radiation, the two-part model was improved by incorporating a measured trunk view component and trunk temperature. Trunk temperature measurements were up to 25°C higher than locally measured air temperatures. This three-part model reduced the RMSE by up to 7.7 W m-2 from the two-part air temperature model at all sensor positions across the 2014 snowmelt season and performed particularly well during periods of high insolation when errors from the two-part model were up to 40 W m-2. A parameterization predicting tree trunk temperatures using measured air temperature and incoming shortwave radiation demonstrate a simple method that can be applied to provide input to the three-part model across midlatitude coniferous forests.

  10. Comparison of MODIS Satellite Land Surface Temperature with Air Temperature along a 5000-metre Elevation Transect on Kilimanjaro, Tanzania.

    NASA Astrophysics Data System (ADS)

    Pepin, N. C.; Williams, R.; Maeda, E. E.

    2015-12-01

    There is concern that high elevations may be warming more rapidly than lower elevations, but there is a lack of observational data from weather stations in the high mountains. One alternative data source is satellite LST (Land Surface Temperature) which has extensive spatial coverage. This study compares instantaneous values of LST (1030 and 2230 local solar time) as measured by the MODIS MOD11A2 product at 1 km resolution with equivalent screen level air temperatures (in the same pixel) measured from a transect of 22 in situ weather stations across Kilimanjaro ranging in elevation from 990 to 5803 m. Data consists of 11 years on the SW slope and 3 years on the NE slope, equating to >500 and ~140 octtads (8-day periods) respectively. Results show substantial differences between LST and local air temperature, sometimes up to 20C. During the day the LST tends to be higher than air temperature and the reverse is true at night. The differences show large variance, particularly during the daytime, and tend to increase with elevation, particularly on the NE slope of the mountain which faces the sun when the daytime observations are taken (1030 LST). Differences between LST and air temperature are larger in the dry seasons (JF and JJAS), and reduce when conditions are more cloudy. Systematic relationships with cloud cover and vegetation characteristics (as measured by NDVI and MAIAC for the same pixel) are displayed. More vegetation reduces daytime surface heating above the air temperature, but this relationship weakens with elevation. Nighttime differences are more stable and show no relationship with vegetation indices. Therefore the predictability of the LST/air temperature differences reduces at high elevations and it is therefore much more challenging to use satellite data at high elevations to complement in situ air temperature measurements for climate change assessments, especially for daytime maximum temperatures.

  11. First Annually Resolved Marine Temperature Series For The Last 1000 Years From The North Atlantic

    NASA Astrophysics Data System (ADS)

    Reynolds, D.; Scourse, J. D.; Richardson, C.; Hall, I. R.; Butler, P.; Nederbragt, A.; Wanamaker, A. D.; Becker, J.

    2013-12-01

    There remain very few high-resolution records of marine climate variability covering the last 1000 years; annually-resolved series have hitherto been confined to coral archives from the low latitude oceans and do not cover the full millennium. We have constructed a 1357-year crossdated sclerochronology based on annual growth increments in the long-lived bivalve mollusc Arctica islandica, collected by dredge from the temperate North Atlantic (Grimsey, North Icelandic shelf, 80 m water depth; Butler et al. 2013). We present here annual- to sub-annually-resolved oxygen isotope data from the last 1000 years of this absolute chronology. Radiocarbon analysis of the series demonstrates variability in the marine reservoir effect (ΔR) controlled by Atlantic vs. Arctic water masses (Irminger Current, East Icelandic Current) with enhanced ingress of Irminger Current water during the Medieval Climate Anomaly and since AD 1900; the Little Ice Age is conversely characterized by Arctic water masses (Wanamaker et al. 2012). We use the ΔR variability to correct for the isotopic content of seawater (δ18Ow) and hence convert δ18Oshell to seawater temperature at 80m, a calibration supported by comparison with instrumental series. This reveals the evolution of North Atlantic seawater temperatures over the last 1000 years in unprecedented detail and provides a basis for the comparison of marine with terrestrial series at the same resolution for the first time.

  12. Homogenisation of minimum and maximum air temperature in northern Portugal

    NASA Astrophysics Data System (ADS)

    Freitas, L.; Pereira, M. G.; Caramelo, L.; Mendes, L.; Amorim, L.; Nunes, L.

    2012-04-01

    Homogenization of minimum and maximum air temperature has been carried out for northern Portugal for the period 1941-2010. The database corresponds to the values of the monthly arithmetic averages calculated from daily values observed at stations within the network of stations managed by the national Institute of Meteorology (IM). Some of the weather stations of IM's network are collecting data for more than a century; however, during the entire observing period, some factors have affected the climate series and have to be considered such as, changes in the station surroundings and changes related to replacement of manually operated instruments. Besides these typical changes, it is of particular interest the station relocation to rural areas or to the urban-rural interface and the installation of automatic weather stations in the vicinity of the principal or synoptic stations with the aim of replacing them. The information from these relocated and new stations was merged to produce just one but representative time series of that site. This process starts at the end 90's and the information of the time series fusion process constitutes the set of metadata used. Two basic procedures were performed: (i) preliminary statistical and quality control analysis; and, (ii) detection and correction of problems of homogeneity. In the first case, was developed and used software for quality control, specifically dedicated for the detection of outliers, based on the quartile values of the time series itself. The analysis of homogeneity was performed using the MASH (Multiple Analysis of Series for Homogenisation) and HOMER, which is a software application developed and recently made available within the COST Action ES0601 (COST-ES0601, 2012). Both methods provide a fast quality control of the original data and were developed for automatic processing, analyzing, homogeneity testing and adjusting of climatological data, but manual usage is also possible. Obtained results with both

  13. Skin sites to predict deep-body temperature while wearing firefighters' personal protective equipment during periodical changes in air temperature.

    PubMed

    Kim, Siyeon; Lee, Joo-Young

    2016-04-01

    The aim of this study was to investigate stable and valid measurement sites of skin temperatures as a non-invasive variable to predict deep-body temperature while wearing firefighters' personal protective equipment (PPE) during air temperature changes. Eight male firefighters participated in an experiment which consisted of 60-min exercise and 10-min recovery while wearing PPE without self-contained breathing apparatus (7.75 kg in total PPE mass). Air temperature was periodically fluctuated from 29.5 to 35.5 °C with an amplitude of 6 °C. Rectal temperature was chosen as a deep-body temperature, and 12 skin temperatures were recorded. The results showed that the forehead and chest were identified as the most valid sites to predict rectal temperature (R(2) = 0.826 and 0.824, respectively) in an environment with periodically fluctuated air temperatures. This study suggests that particular skin temperatures are valid as a non-invasive variable when predicting rectal temperature of an individual wearing PPE in changing ambient temperatures. Practitioner Summary: This study should offer assistance for developing a more reliable indirect indicating system of individual heat strain for firefighters in real time, which can be used practically as a precaution of firefighters' heat-related illness and utilised along with physiological monitoring. PMID:26214379

  14. Air-Cooled Design of a Temperature-Swing Adsorption Compressor for Closed-Loop Air Revitalization Systems

    NASA Technical Reports Server (NTRS)

    Mulloth, Lila M.; Affleck, Dave L.; Rosen, Micha; LeVan, M. Douglas; Wang, Yuan; Cavalcante, Celio L.

    2004-01-01

    The air revitalization system of the International Space Station (ISS) operates in an open loop mode and relies on the resupply of oxygen and other consumables from earth for the life support of astronauts. A compressor is required for delivering the carbon dioxide from a removal assembly to a reduction unit to recover oxygen and thereby closing the air-loop. We have a developed a temperature-swing adsorption compressor (TSAC) for performing these tasks that is energy efficient, quiet, and has no rapidly moving parts. This paper discusses the mechanical design and the results of thermal model validation tests of a TSAC that uses air as the cooling medium.

  15. Air temperature suitability for Plasmodium falciparum malaria transmission in Africa 2000-2012: a high-resolution spatiotemporal prediction

    PubMed Central

    2014-01-01

    Background Temperature suitability for malaria transmission is a useful predictor variable for spatial models of malaria infection prevalence. Existing continental or global models, however, are synoptic in nature and so do not characterize inter-annual variability in seasonal patterns of temperature suitability, reducing their utility for predicting malaria risk. Methods A malaria Temperature Suitability Index (TSI) was created by first modeling minimum and maximum air temperature with an eight-day temporal resolution from gap-filled MODerate Resolution Imaging Spectroradiometer (MODIS) daytime and night-time Land Surface Temperature (LST) datasets. An improved version of an existing biological model for malaria temperature suitability was then applied to the resulting temperature information for a 13-year data series. The mechanism underlying this biological model is simulation of emergent mosquito cohorts on a two-hour time-step and tracking of each cohort throughout its life to quantify the impact air temperature has on both mosquito survival and sporozoite development. Results The results of this research consist of 154 monthly raster surfaces that characterize spatiotemporal patterns in TSI across Africa from April 2000 through December 2012 at a 1 km spatial resolution. Generalized TSI patterns were as expected, with consistently high values in equatorial rain forests, seasonally variable values in tropical savannas (wet and dry) and montane areas, and low values in arid, subtropical regions. Comparisons with synoptic approaches demonstrated the additional information available within the dynamic TSI dataset that is lost in equivalent synoptic products derived from long-term monthly averages. Conclusions The dynamic TSI dataset presented here provides a new product with far richer spatial and temporal information than any other presently available for Africa. As spatiotemporal malaria modeling endeavors evolve, dynamic predictor variables such as the malaria

  16. Determination of needed parameters for measuring temperature fields in air by thermography

    NASA Astrophysics Data System (ADS)

    Pešek, Martin; Pavelek, Milan

    2012-04-01

    The aim of this article is the parameters determination of equipment for measuring temperature fields in air using an infrared camera. This method is based on the visualization of temperature fields in an auxiliary material, which is inserted into the non-isothermal air flow. The accuracy of air temperature measurement (or of surface temperature of supplies) by this method depends especially on (except for parameters of infrared camera) the determination of the static and the dynamic qualities of auxiliary material. The emissivity of support material is the static quality and the dynamic quality is time constant. Support materials with a high emissivity and a low time constant are suitable for the measurement. The high value of emissivity results in a higher measurement sensitivity and the radiation temperature independence. In this article the emissivity of examined kinds of auxiliary materials (papers and textiles) is determined by temperature measuring of heated samples by a calibrated thermocouple and by thermography, with the emissivity setting on the camera to 1 and with the homogeneous radiation temperature. Time constants are determined by a step change of air temperature in the surrounding of auxiliary material. The time constant depends mainly on heat transfer by the convection from the air into the auxiliary material. That is why the effect of air temperature is examined in this article (or a temperature difference towards the environmental temperature) and the flow velocity on the time constant with various types of auxiliary materials. The obtained results allow to define the conditions for using the method of measurement of temperature fields in air during various heating and air conditioning applications.

  17. Effect of pyrolysis temperature and air flow on toxicity of gases from a polycarbonate polymer

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Brick, V. E.; Brauer, D. P.

    1978-01-01

    A polycarbonate polymer was evaluated for toxicity of pyrolysis gases generated at various temperatures without forced air flow and with 1 L/min air flow, using the toxicity screening test method developed at the University of San Francisco. Time to various animal responses decreased with increasing pyrolysis temperature over the range from 500 C to 800 C. There appeared to be no significant toxic effects at 400 C and lower temperatures.

  18. The EUSTACE project: delivering global, daily information on surface air temperature

    NASA Astrophysics Data System (ADS)

    Morice, C. P.; Rayner, N. A.; Auchmann, R.; Bessembinder, J.; Bronnimann, S.; Brugnara, Y.; Conway, E. A.; Ghent, D.; Good, E.; Herring, K.; Kennedy, J.; Lindgren, F.; Madsen, K. S.; Merchant, C. J.; van der Schrier, G.; Stephens, A.; Tonboe, R. T.; Waterfall, A. M.; Mitchelson, J.; Woolway, I.

    2015-12-01

    Day-to-day variations in surface air temperature affect society in many ways; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, we must develop an understanding of the relationships between traditional (land and marine) surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. These relationships can be derived either empirically or with the help of a physical model.Here we discuss the science needed to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types. Information contained in the satellite retrievals would be used to create globally-complete fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place. As the data volumes involved are considerable, such work needs to include development of new "Big Data" analysis methods.We will present plans and progress along this road in the EUSTACE project (2015-June 2018), i.e.: • providing new, consistent, multi-component estimates of uncertainty in surface skin temperature retrievals from satellites; • identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; • estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; • using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras.Information will also be given on how interested users can become

  19. An ecological study on air pollution: Changes in annual ring growth of the Japanese cedar and prevalence of respiratory symptoms in schoolchildren in Japanese rural districts

    SciTech Connect

    Kagamimori, S.; Katoh, T.; Naruse, Y.; Kakiuchi, H.; Matsubara, I.; Kasuya, M.; Kawano, S. )

    1990-06-01

    The effect of air pollution caused by oil-fired electricity-generating stations on the annual ring growth of the Japanese cedar (Cryptomeria japonica, D. Don) and prevalence of respiratory symptoms in schoolchildren were investigated. By retrospective analysis the annual ring growth has been demonstrated to show good agreement with the general trend in air pollution. In addition it was found to be related to the prevalence of respiratory symptoms. The reduction in annual ring growth and increase in the prevalence of respiratory symptoms followed a deterioration in air pollution. Following upgrading of the power station and an improvement in air pollution, the annual ring growth and prevalence of respiratory symptoms showed opposite changes, respectively. Concerning the latter, the prevalence of wheezing and respiratory symptoms associated with school absence in schoolchildren with a positive skin test to house dust extract showed a closer correlation with the annual ring growth when compared with those who had never had a positive skin test.

  20. Some Effects of Air and Fuel Oil Temperatures on Spray Penetration and Dispersion

    NASA Technical Reports Server (NTRS)

    Gelalles, A G

    1930-01-01

    Presented here are experimental results obtained from a brief investigation of the appearance, penetration, and dispersion of oil sprays injected into a chamber of highly heated air at atmospheric pressure. The development of single sprays injected into a chamber containing air at room temperature and at high temperature was recorded by spray photography equipment. A comparison of spray records showed that with the air at the higher temperature, the spray assumed the appearance of thin, transparent cloud, the greatest part of which rapidly disappeared from view. With the chamber air at room temperature, a compact spray with an opaque core was obtained. Measurements of the records showed a decrease in penetration and an increase in the dispersion of the spray injected into the heated air. No ignition of the fuel injected was observed or recorded until the spray particles came in contact with the much hotter walls of the chamber about 0.3 second after the start of injection.

  1. Validation of AIRS V6 Surface Temperature over Greenland with GCN and NOAA Stations

    NASA Technical Reports Server (NTRS)

    Lee, Jae N.; Hearty, Thomas; Cullather, Richard; Nowicki, Sophie; Susskind, Joel

    2016-01-01

    This work compares the temporal and spatial characteristics of the AIRSAMSU (Atmospheric Infrared Sounder Advanced Microwave Sounding Unit A) Version 6 and MODIS (Moderate resolution Imaging Spectroradiometer) Collection 5 derived surface temperatures over Greenland. To estimate uncertainties in space-based surface temperature measurements, we re-projected the MODIS Ice Surface Temperature (IST) to 0.5 by 0.5 degree spatial resolution. We also re-gridded AIRS Skin Temperature (Ts) into the same grid but classified with different cloud conditions and surface types. These co-located data sets make intercomparison between the two instruments relatively straightforward. Using this approach, the spatial comparison between the monthly mean AIRS Ts and MODIS IST is in good agreement with RMS 2K for May 2012. This approach also allows the detection of any long-term calibration drift and the careful examination of calibration consistency in the MODIS and AIRS temperature data record. The temporal correlations between temperature data are also compared with those from in-situ measurements from GC-Net (GCN) and NOAA stations. The coherent time series of surface temperature evident in the correlation between AIRS Ts and GCN temperatures suggest that at monthly time scales both observations capture the same climate signal over Greenland. It is also suggested that AIRS surface air temperature (Ta) can be used to estimate the boundary layer inversion.

  2. Attribution of precipitation changes on ground-air temperature offset: Granger causality analysis

    NASA Astrophysics Data System (ADS)

    Cermak, Vladimir; Bodri, Louise

    2016-06-01

    This work examines the causal relationship between the value of the ground-air temperature offset and the precipitation changes for monitored 5-min data series together with their hourly and daily averages obtained at the Sporilov Geophysical Observatory (Prague). Shallow subsurface soil temperatures were monitored under four different land cover types (bare soil, sand, short-cut grass and asphalt). The ground surface temperature (GST) and surface air temperature (SAT) offset, ΔT(GST-SAT), is defined as the difference between the temperature measured at the depth of 2 cm below the surface and the air temperature measured at 5 cm above the surface. The results of the Granger causality test did not reveal any evidence of Granger causality for precipitation to ground-air temperature offsets on the daily scale of aggregation except for the asphalt pavement. On the contrary, a strong evidence of Granger causality for precipitation to the ground-air temperature offsets was found on the hourly scale of aggregation for all land cover types except for the sand surface cover. All results are sensitive to the lag choice of the autoregressive model. On the whole, obtained results contain valuable information on the delay time of ΔT(GST-SAT) caused by the rainfall events and confirmed the importance of using autoregressive models to understand the ground-air temperature relationship.

  3. Energy impact of various inside air temperatures and humidities in a museum when located in five U. S. cities

    SciTech Connect

    Ayres, J.M.; Lau, H.; Haiad, J.C. )

    1990-01-01

    The art conservation literature presents a wide range of recommended temperatures and relative humidities required to protect the safety of collections in museums, but the operating energy costs for specific criteria have not been identified. The Scott Gallery at the Huntington Library and Art Gallery in San Marino, CA, was selected for a detailed study of energy costs associated with recommended environmental levels for museums. The results of computer simulations of the Scott Gallery when located in Albuquerque, NM; Burbank, CA; Minneapolis, MN; New Orleans, LA; and New York, NY are presented. The simulations were performed suing the DOE-2 building energy analysis computer program. The peak heating and cooling load components are identified, thermal zone loads quantified, and psychrometric analysis of the annual energy requirements with fixed and variable inside air temperature and relative humidity (RH) setpoints are presented. In all five climate regions the minimum energy consumption occurred with a 70 {degree} F and 50% RH setpoint.

  4. The influence of air-conditioning on street temperatures in the city of Paris

    NASA Astrophysics Data System (ADS)

    de Munck, C. S.; Pigeon, G.; Masson, V.; Marchadier, C.; Meunier, F.; Tréméac, B.; Merchat, M.

    2010-12-01

    A consequence of urban heat islands in summer is the increased use of air-conditioning during extreme heat events : the use of air-conditioning systems, while cooling the inside of buildings releases waste heat (as latent and sensible heat) in the lower part of the urban atmosphere, hence potentially increasing air street temperatures where the heat is released. This may lead locally to a further increase in air street temperatures, therefore increasing the air cooling demand, while at the same time lowering the efficiency of air-conditioning units. A coupled model consisting of a meso-scale meteorological model (MESO-NH) and an urban energy balance model (TEB) has been implemented with an air-conditioning module and used in combination to real spatialised datasets to understand and quantify potential increases in temperature due to air-conditioning heat releases for the city of Paris . In a first instance, the current types of air-conditioning systems co-existing in the city were simulated (underground chilled water network, wet cooling towers and individual air-conditioning units) to study the effects of latent and sensible heat releases on street temperatures. In a third instance, 2 scenarios were tested to characterise the impacts of likely future trends in air-conditioning equipment in the city : a first scenario for which current heat releases were converted to sensible heat, and a second based on 2030s projections of air-conditioning equipment at the scale of the city. All the scenarios showed an increase in street temperature which, as expected, was greater at night time than day time. For the first two scenarios, this increase in street temperatures was localised at or near the sources of air-conditioner heat releases, while the 2030s air-conditioning scenario impacted wider zones in the city. The amplitude of the increase in temperature varied from 0,25°C to 1°C for the air-conditioning current state, between 0,25°C and 2°C for the sensible heat

  5. Exchange of Groundwater and Surface-Water Mediated by Permafrost Response to Seasonal and Long Term Air Temperature Variation

    USGS Publications Warehouse

    Ge, Shemin; McKenzie, Jeffrey; Voss, Clifford; Wu, Qingbai

    2011-01-01

    Permafrost dynamics impact hydrologic cycle processes by promoting or impeding groundwater and surface water exchange. Under seasonal and decadal air temperature variations, permafrost temperature changes control the exchanges between groundwater and surface water. A coupled heat transport and groundwater flow model, SUTRA, was modified to simulate groundwater flow and heat transport in the subsurface containing permafrost. The northern central Tibet Plateau was used as an example of model application. Modeling results show that in a yearly cycle, groundwater flow occurs in the active layer from May to October. Maximum groundwater discharge to the surface lags the maximum subsurface temperature by two months. Under an increasing air temperature scenario of 3?C per 100 years, over the initial 40-year period, the active layer thickness can increase by three-fold. Annual groundwater discharge to the surface can experience a similar three-fold increase in the same period. An implication of these modeling results is that with increased warming there will be more groundwater flow in the active layer and therefore increased groundwater discharge to rivers. However, this finding only holds if sufficient upgradient water is available to replenish the increased discharge. Otherwise, there will be an overall lowering of the water table in the recharge portion of the catchment.

  6. Exchange of groundwater and surface-water mediated by permafrost response to seasonal and long term air temperature variation

    USGS Publications Warehouse

    Ge, S.; McKenzie, J.; Voss, C.; Wu, Q.

    2011-01-01

    Permafrost dynamics impact hydrologic cycle processes by promoting or impeding groundwater and surface water exchange. Under seasonal and decadal air temperature variations, permafrost temperature changes control the exchanges between groundwater and surface water. A coupled heat transport and groundwater flow model, SUTRA, was modified to simulate groundwater flow and heat transport in the subsurface containing permafrost. The northern central Tibet Plateau was used as an example of model application. Modeling results show that in a yearly cycle, groundwater flow occurs in the active layer from May to October. Maximum groundwater discharge to the surface lags the maximum subsurface temperature by two months. Under an increasing air temperature scenario of 3C per 100 years, over the initial 40-year period, the active layer thickness can increase by three-fold. Annual groundwater discharge to the surface can experience a similar three-fold increase in the same period. An implication of these modeling results is that with increased warming there will be more groundwater flow in the active layer and therefore increased groundwater discharge to rivers. However, this finding only holds if sufficient upgradient water is available to replenish the increased discharge. Otherwise, there will be an overall lowering of the water table in the recharge portion of the catchment. Copyright 2011 by the American Geophysical Union.

  7. A comparison of urban heat islands mapped using skin temperature, air temperature, and apparent temperature (Humidex), for the greater Vancouver area.

    PubMed

    Ho, Hung Chak; Knudby, Anders; Xu, Yongming; Hodul, Matus; Aminipouri, Mehdi

    2016-02-15

    Apparent temperature is more closely related to mortality during extreme heat events than other temperature variables, yet spatial epidemiology studies typically use skin temperature (also known as land surface temperature) to quantify heat exposure because it is relatively easy to map from satellite data. An empirical approach to map apparent temperature at the neighborhood scale, which relies on publicly available weather station observations and spatial data layers combined in a random forest regression model, was demonstrated for greater Vancouver, Canada. Model errors were acceptable (cross-validated RMSE=2.04 °C) and the resulting map of apparent temperature, calibrated for a typical hot summer day, corresponded well with past temperature research in the area. A comparison with field measurements as well as similar maps of skin temperature and air temperature revealed that skin temperature was poorly correlated with both air temperature (R(2)=0.38) and apparent temperature (R(2)=0.39). While the latter two were more similar (R(2)=0.87), apparent temperature was predicted to exceed air temperature by more than 5 °C in several urban areas as well as around the confluence of the Pitt and Fraser rivers. We conclude that skin temperature is not a suitable proxy for human heat exposure, and that spatial epidemiology studies could benefit from mapping apparent temperature, using an approach similar to the one reported here, to better quantify differences in heat exposure that exist across an urban landscape. PMID:26706765

  8. Modelling near subsurface temperature with mixed type boundary condition for transient air temperature and vertical groundwater flow

    NASA Astrophysics Data System (ADS)

    Kumar, Rajeev Ranjan; Ramana, D. V.; Singh, R. N.

    2012-10-01

    Near-subsurface temperatures have signatures of climate change. Thermal models of subsurface have been constructed by prescribing time dependent Dirichlet type boundary condition wherein the temperature at the soil surface is prescribed and depth distribution of temperature is obtained. In this formulation it is not possible to include the relationship between air temperatures and the temperature of soil surface. However, if one uses a Robin type boundary condition, a transfer coefficient relates the air and soil surface temperatures which helps to determine both the temperature at the surface and at depth given near surface air temperatures. This coefficient is a function of meteorological conditions and is readily available. We have developed such a thermal model of near subsurface region which includes both heat conduction and advection due to groundwater flows and have presented numerical results for changes in the temperature-depth profiles for different values of transfer coefficient and groundwater flux. There are significant changes in temperature and depth profiles due to changes in the transfer coefficient and groundwater flux. The analytical model will find applications in the interpretation of the borehole geothermal data to extract both climate and groundwater flow signals.

  9. Investigation of the impact of extreme air temperature on river water temperature: case study of the heat episode 2013.

    NASA Astrophysics Data System (ADS)

    Weihs, Philipp; Trimmel, Heidelinde; Goler, Robert; Formayer, Herbert; Holzapfel, Gerda; Rauch, Hans Peter

    2014-05-01

    Water stream temperature is a relevant factor for water quality since it is an important driver of water oxygen content and in turn also reduces or increases stress on the aquatic fauna. The water temperature of streams is determined by the source and inflow water temperature, by the energy balance at the stream surface and by the hydrological regime of the stream. Main factors driving the energy balance of streams are radiation balance and air temperature which influences the sensitive and latent heat flux. The present study investigates the impact of the heat episode of summer 2013 on water temperature of two lowland rivers in south eastern Austria. Within the scope of the project BIO_CLIC routine measurements of water temperature at 33 locations alongside the rivers Pinka and Lafnitz have been performed since spring 2012. In addition meteorological measurements of global shortwave and longwave radiation, air temperature, wind and air humidity have been carried out during this time. For the same time period, data of discharge and water levels of both rivers were provided by the public hydrological office. The heat episode of summer 2013 started, according to the Kysely- definition, on 18 July and lasted until 14 August. The highest air temperature ever recorded in Austria was reported on 8 August at 40.5°C. In Güssing, which is located within the project area, 40.0 °C were recorded. In the lower reaches of the river Pinka, at the station Burg the monthly mean water temperature of August 2013 was with more than 22°C, 1°C higher than the mean water temperature of the same period of the previous years. At the same station, the maximum water temperature of 27.1°C was recorded on 29 July, 9 days prior to the air temperature record. Analysis shows that at the downstream stations the main driving parameter is solar radiation whereas at the upstream stations a better correlation between air temperature and water temperature is obtained. Using the extensive data set

  10. Annual variation in temperature and composition of the thermosphere and upper mesosphere

    NASA Technical Reports Server (NTRS)

    Mayr, H. G.; Harris, I.

    1977-01-01

    A three-dimensional circulation model, including UV (O2 dissociation) and EUV sources, is used to study the wind field and the effects of temperature and composition on annual thermospheric variations. The results are compared to those of OGO-6 and AE-C. Within an 800-1200 K temperature range, summer to winter temperature variation is studied as a function of solar activity. It is found that the model correctly predicts H, He, O, N2, O2, and Ar measurements. It is suggested that a small winter maximum in mesospheric temperature is caused by large-scale circulation induced by EUV heating. This effect, however, is masked by the energy released in O2 dissociation. The annual temperature amplitude and the winter oxygen bulge are noted to increase with increasing solar activity, whereas the winter helium bulge is noted to decrease with enhanced exospheric return flow. It is felt that the dependence of the F2 region winter anomaly on solar activity may be significantly affected by the solar activity effect in atomic oxygen.

  11. Geographical and Geomorphological Effects on Air Temperatures in the Columbia Basin's Signature Vineyards

    NASA Astrophysics Data System (ADS)

    Olson, L.; Pogue, K. R.; Bader, N.

    2012-12-01

    The Columbia Basin of Washington and Oregon is one of the most productive grape-growing areas in the United States. Wines produced in this region are influenced by their terroir - the amalgamation of physical and cultural elements that influence grapes grown at a particular vineyard site. Of the physical factors, climate, and in particular air temperature, has been recognized as a primary influence on viticulture. Air temperature directly affects ripening in the grapes. Proper fruit ripening, which requires precise and balanced levels of acid and sugar, and the accumulation of pigment in the grape skin, directly correlates with the quality of wine produced. Many features control air temperature within a particular vineyard. Elevation, latitude, slope, and aspect all converge to form complex relationships with air temperatures; however, the relative degree to which these attributes affect temperatures varies between regions and is not well understood. This study examines the influence of geography and geomorphology on air temperatures within the American Viticultural Areas (AVAs) of the Columbia Basin in eastern Washington and Oregon. The premier vineyards within each AVA, which have been recognized for producing high-quality wine, were equipped with air temperature monitoring stations that collected hourly temperature measurements. A variety of temperature statistics were calculated, including daily average, maximum, and minimum temperatures. From these values, average diurnal variation and growing degree-days (10°C) were calculated. A variety of other statistics were computed, including date of first and last frost and time spent below a minimum temperature threshold. These parameters were compared to the vineyard's elevation, latitude, slope, aspect, and local topography using GPS, ArcCatalog, and GIS in an attempt to determine their relative influences on air temperatures. From these statistics, it was possible to delineate two trends of temperature variation

  12. Robust Comparison of Climate Models with Observations Using Blended Land Air and Ocean Sea Surface Temperatures

    NASA Astrophysics Data System (ADS)

    Hausfather, Z.; Jacobs, P.; Cowtan, K.; Hawkins, E.; Mann, M. E.; Miller, S. K.; Steinman, B. A.; Way, R. G.; Stolpe, M.

    2015-12-01

    Model-observation comparisons provide an important test of climate models' ability to realistically simulate the transient evolution of the system. A great deal of attention has recently focused on the so-called "hiatus" period of the past ~15 years, when estimates of recent surface temperature evolution fall at the lower end of climate model projections. This work quantifies a systematic bias in model-observation comparisons arising from differential warming rates between sea surface temperatures and surface air temperatures over oceans. Global mean temperatures from climate model simulations are typically calculated using surface air temperatures, while the corresponding observations are based on a blend of air and sea surface temperatures. A further bias arises from the treatment of temperatures in regions where the sea ice boundary has changed. We discuss the magnitude of these biases, and their implications for the evaluation of climate model performance over the "hiatus" period and the full instrumental record.

  13. Modeling Validation and Control Analysis for Controlled Temperature and Humidity of Air Conditioning System

    PubMed Central

    Lee, Jing-Nang; Lin, Tsung-Min

    2014-01-01

    This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14°C, 0006 kgw/kgda in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system. PMID:25250390

  14. Oxide modified air electrode surface for high temperature electrochemical cells

    DOEpatents

    Singh, Prabhakar; Ruka, Roswell J.

    1992-01-01

    An electrochemical cell is made having a porous cermet electrode (16) and a porous lanthanum manganite electrode (14), with solid oxide electrolyte (15) between them, where the lanthanum manganite surface next to the electrolyte contains a thin discontinuous layer of high surface area cerium oxide and/or praseodymium oxide, preferably as discrete particles (30) in contact with the air electrode and electrolyte.

  15. Stability limit of room air temperature of a VAV system

    SciTech Connect

    Matsuba, Tadahiko; Kamimura, Kazuyuki; Kasahara, Masato; Kimbara, Akiomi; Kurosu, Shigeru; Murasawa, Itaru; Hashimoto, Yukihiko

    1998-12-31

    To control heating, ventilating, and air-conditioning (HVAC) systems, it has been necessary to accept an analog system controlled mainly by proportional-plus-integral-plus-derivative (PID) action. However, when conventional PID controllers are replaced with new digital controllers by selecting the same PID parameters as before, the control loops have often got into hunting phenomena, which result in undamped oscillations. Unstable control characteristics (such as huntings) are thought to be one of the crucial problems faced by field operators. The PID parameters must be carefully selected to avoid instabilities. In this study, a room space is simulated as a thermal system that is air-conditioned by a variable-air-volume (VAV) control system. A dynamic room model without infiltration or exfiltration, which is directly connected to a simple air-handling unit without an economizer, is developed. To explore the possible existence of huntings, a numerical system model is formulated as a bilinear system with time-delayed feedback, and a parametric analysis of the stability limit is presented. Results are given showing the stability region affected by the selection of control and system parameters. This analysis was conducted to help us tune the PID controllers for optimal HVAC control.

  16. Measured Performance of a Low Temperature Air Source Heat Pump

    SciTech Connect

    R.K. Johnson

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor “boosted heat pump” technology. The Low Temperature Heat Pump system operates with four increasing levels of capacity (heat output) as the outdoor temperature drops.

  17. Combustion of Gaseous Fuels with High Temperature Air in Normal- and Micro-gravity Conditions

    NASA Technical Reports Server (NTRS)

    Wang, Y.; Gupta, A. K.

    2001-01-01

    The objective of this study is determine the effect of air preheat temperature on flame characteristics in normal and microgravity conditions. We have obtained qualitative (global flame features) and some quantitative information on the features of flames using high temperature combustion air under normal gravity conditions with propane and methane as the fuels. This data will be compared with the data under microgravity conditions. The specific focus under normal gravity conditions has been on determining the global flame features as well as the spatial distribution of OH, CH, and C2 from flames using high temperature combustion air at different equivalence ratio.

  18. Monitoring of cave air temperature and humidity in the Niedźwiedzia Cave system (Sudetes, Poland) - a key to understanding tourists activity impact to cave environment

    NASA Astrophysics Data System (ADS)

    Gasiorowski, M.; Hercman, H.

    2012-04-01

    The Niedźwiedzia Cave is located in Śnieżnik Massif (the Easter Sudetes, SW Poland) at 800 m a.s.l. The length of known passages is ~3000 m and denivelation is 69 m. The system is composed of 3 levels of passages and chambers. It is a show cave with ~80,000 visitors every year. In 2010 we started monitoring program of cave air temperature and humidity, drip rate, stable isotopes and Uranium and Polonium content in water in selected sites inside the cave and in its vicinity. Changes in dropping rate in upper level are well correlated with precipitation. However, a response of dripping to rainfall depends on former precipitation frequency and intensity - during the humid period the dripping reacts immediately and after long dry period dripping responses with two-weeks delay. There is not so direct correlation between precipitation and dripping in lower level of the system. Air temperature inside the cave is almost stable in lower level (mean annual ~5.3 °C, and annual variation up to 0.7 °C) and more dynamic in the middle level (mean annual ~6.4 °C, and mean annual amplitude up to 4 °C). Daily and weekly measured changes of cave air temperature demonstrate extremely well correlation with number of visitors. In show cave passages (the middle level of the system) temperature increase 0.1-0.2 °C during every day when the cave is open for tourists and such changes is not observed during days without visitors and in lower level of the system closed for tourists. But even short visits of 3-4 cavers are recorded by temperature sensors exposed in the lower level (~0.02 °C increase). It proves very high sensitivity of cave environment to human activity. This study is funded by the National Science Centre and Higher Education grant no. N N306 131038.

  19. Improved Temperature Sounding and Quality Control Methodology Using AIRS/AMSU Data: The AIRS Science Team Version 5 Retrieval Algorithm

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Blaisdell, John M.; Iredell, Lena; Keita, Fricky

    2009-01-01

    This paper describes the AIRS Science Team Version 5 retrieval algorithm in terms of its three most significant improvements over the methodology used in the AIRS Science Team Version 4 retrieval algorithm. Improved physics in Version 5 allows for use of AIRS clear column radiances in the entire 4.3 micron CO2 absorption band in the retrieval of temperature profiles T(p) during both day and night. Tropospheric sounding 15 micron CO2 observations are now used primarily in the generation of clear column radiances .R(sub i) for all channels. This new approach allows for the generation of more accurate values of .R(sub i) and T(p) under most cloud conditions. Secondly, Version 5 contains a new methodology to provide accurate case-by-case error estimates for retrieved geophysical parameters and for channel-by-channel clear column radiances. Thresholds of these error estimates are used in a new approach for Quality Control. Finally, Version 5 also contains for the first time an approach to provide AIRS soundings in partially cloudy conditions that does not require use of any microwave data. This new AIRS Only sounding methodology, referred to as AIRS Version 5 AO, was developed as a backup to AIRS Version 5 should the AMSU-A instrument fail. Results are shown comparing the relative performance of the AIRS Version 4, Version 5, and Version 5 AO for the single day, January 25, 2003. The Goddard DISC is now generating and distributing products derived using the AIRS Science Team Version 5 retrieval algorithm. This paper also described the Quality Control flags contained in the DISC AIRS/AMSU retrieval products and their intended use for scientific research purposes.

  20. Indispensable Resources for Institutional Researchers: An Analysis of AIR Publication Topics Since 1974. AIR 1997 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Volkwein, J. Fredericks

    This study identified and classified the Association for Institutional Research (AIR) publication topics and authors since 1973 in order to provide a reference resource for institutional researchers. The study reviewed the following AIR publication collections: "Research in Higher Education"; "New Directions for Institutional Research"; "Resources…

  1. Unusually high soil nitrogen oxide emissions influence air quality in a high-temperature agricultural region

    NASA Astrophysics Data System (ADS)

    Oikawa, P. Y.; Ge, C.; Wang, J.; Eberwein, J. R.; Liang, L. L.; Allsman, L. A.; Grantz, D. A.; Jenerette, G. D.

    2015-11-01

    Fertilized soils have large potential for production of soil nitrogen oxide (NOx=NO+NO2), however these emissions are difficult to predict in high-temperature environments. Understanding these emissions may improve air quality modelling as NOx contributes to formation of tropospheric ozone (O3), a powerful air pollutant. Here we identify the environmental and management factors that regulate soil NOx emissions in a high-temperature agricultural region of California. We also investigate whether soil NOx emissions are capable of influencing regional air quality. We report some of the highest soil NOx emissions ever observed. Emissions vary nonlinearly with fertilization, temperature and soil moisture. We find that a regional air chemistry model often underestimates soil NOx emissions and NOx at the surface and in the troposphere. Adjusting the model to match NOx observations leads to elevated tropospheric O3. Our results suggest management can greatly reduce soil NOx emissions, thereby improving air quality.

  2. Unusually high soil nitrogen oxide emissions influence air quality in a high-temperature agricultural region.

    PubMed

    Oikawa, P Y; Ge, C; Wang, J; Eberwein, J R; Liang, L L; Allsman, L A; Grantz, D A; Jenerette, G D

    2015-01-01

    Fertilized soils have large potential for production of soil nitrogen oxide (NOx=NO+NO2), however these emissions are difficult to predict in high-temperature environments. Understanding these emissions may improve air quality modelling as NOx contributes to formation of tropospheric ozone (O3), a powerful air pollutant. Here we identify the environmental and management factors that regulate soil NOx emissions in a high-temperature agricultural region of California. We also investigate whether soil NOx emissions are capable of influencing regional air quality. We report some of the highest soil NOx emissions ever observed. Emissions vary nonlinearly with fertilization, temperature and soil moisture. We find that a regional air chemistry model often underestimates soil NOx emissions and NOx at the surface and in the troposphere. Adjusting the model to match NOx observations leads to elevated tropospheric O3. Our results suggest management can greatly reduce soil NOx emissions, thereby improving air quality. PMID:26556236

  3. Unusually high soil nitrogen oxide emissions influence air quality in a high-temperature agricultural region

    PubMed Central

    Oikawa, P. Y.; Ge, C.; Wang, J.; Eberwein, J. R.; Liang, L. L.; Allsman, L. A.; Grantz, D. A.; Jenerette, G. D.

    2015-01-01

    Fertilized soils have large potential for production of soil nitrogen oxide (NOx=NO+NO2), however these emissions are difficult to predict in high-temperature environments. Understanding these emissions may improve air quality modelling as NOx contributes to formation of tropospheric ozone (O3), a powerful air pollutant. Here we identify the environmental and management factors that regulate soil NOx emissions in a high-temperature agricultural region of California. We also investigate whether soil NOx emissions are capable of influencing regional air quality. We report some of the highest soil NOx emissions ever observed. Emissions vary nonlinearly with fertilization, temperature and soil moisture. We find that a regional air chemistry model often underestimates soil NOx emissions and NOx at the surface and in the troposphere. Adjusting the model to match NOx observations leads to elevated tropospheric O3. Our results suggest management can greatly reduce soil NOx emissions, thereby improving air quality. PMID:26556236

  4. Air temperature and humidity diversity in the Hornsund fjord area (Spitsbergen) in the period 1 July 2014 - 30 June 2015

    NASA Astrophysics Data System (ADS)

    Przybylak, Rajmund; Araźny, Andrzej; Wyszyński, Przemysław; Budzik, Tomasz; Wawrzyniak, Tomasz

    2016-04-01

    The article presents preliminary results of studies into the spatial diversity of air temperature and relative humidity (overground layer, 2 m a.g.l.) in the area of the Hornsund fjord (S Spitsbergen, approx. 77°N), based on data collected between 1 July 2014 and 30 June 2015. The Hornsund fjord runs latitudinal along approx. 40 km and its average width is about 10 km. Numerous glaciers flow into the fjord and the mountain ridges around it often exceed 700 m a.s.l. Data series obtained from 11 sites equipped with automatic weather stations (Vaisala, Campbell, Davis) or HOBO temperature and humidity sensors were used. Two sites (Hornsund HOR and the Hans Glacier HG4) have been operating for years, whereas 9 new ones (Bogstranda BOG, Fugleberget FUG, Gnålodden GNA, Gåshamnoyra GAS, Hyttevika HYT, Lisbetdalen LIS, Ostrogradskijfjella OST, Treskelodden TRE and Wilczekodden WIL) were established within the Polish-Norwegian AWAKE-2 project. Three of the sites (BOG, GAS and OST) were damaged by polar bears, hence their measurement series are shorter. A substantial spatial diversity was found in the air temperature and relative humidity in the area, mostly influenced by elevation, type of surface and distance from the Greenland Sea's open water. During the year (July 2014 - June 2015), the areas of HYT (-1.1°C) and WIL (-1.9°C) were the warmest. Both sites are located on the west coast of the fjord. The HYT demonstrates the most favourable temperature conditions, being orographically sheltered from the east and its cold and dry air masses. The coldest sites were the mountain-top site of FUG (-5.9°C) and the glacier-located HG4 (-4.3°C). The low temperature at FUG resulted from its elevation (568 m a.s.l.), whereas at HG4 (184 m a.s.l) the glaciated surface also added up to the result. In the analysed period, the annual course of air temperature in the area had a clear minimum in February, when the lowest mean monthly values ranged from -9.4°C at HYT to -15.1°C at

  5. Effect of air preheat temperature and oxygen concentration on flame structure and emission

    SciTech Connect

    Bolz, S.; Gupta, A.K.

    1998-07-01

    The structure of turbulent diffusion flames with highly preheated combustion air (air preheat temperature in excess of 1,150 C) has been obtained using a specially designed regenerative combustion furnace. Propane gas was used as the fuel. Data have been obtained on the global flame features, spectral emission characteristics, spatial distribution of OH, CH and C{sub 2} species, and pollutants emission from the flames. The results have been obtained for various degrees of air preheat temperatures and O{sub 2} concentration in the air. The color of the flame was found to change from yellow to blue to bluish-green to green over the range of conditions examined. In some cases a hybrid color flame was also observed. The recorded images of the flame photographs were analyzed using color-analyzing software. The results show that thermal and chemical flame behavior strongly depends on the air preheat temperature and oxygen content in the air. The flame color was found to be bluish-green or green at very high air preheat temperatures and low-oxygen concentration. However, at high oxygen concentration the flame color was yellow. The flame volume was found to increase with increase in air-preheat temperature and decrease in oxygen concentration. The flame length showed a similar behavior. The concentrations of OH, CH and C{sub 2} increased with an increase in air preheat temperatures. These species exhibited a two-stage combustion behavior at low oxygen concentration and single stage combustion behavior at high oxygen concentration in the air. Stable flames were obtained for remarkably low equivalence ratios, which would not be possible with normal combustion air. Pollutants emission, including CO{sub 2} and NO{sub x} , was much lower with highly preheated combustion air at low O{sub 2} concentration than the normal air. The results also suggest uniform flow and flame thermal characteristics with conditioned highly preheated air. Highly preheated air combustion provides much

  6. Sampling Biases in Datasets of Historical Mean Air Temperature over Land

    NASA Astrophysics Data System (ADS)

    Wang, K.

    2014-12-01

    Global mean surface air temperature have risen by 0.74 °C over the last 100 years. However, the definition of mean surface air temperature is still a subject of debate. The most defensible definition might be the integral of the continuous temperature measurements over a day (Td0). However, for technological and historical reasons, mean temperatures (Td1) over land have been taken to be the average of the daily maximum and minimum temperature measurements. All existing principle global temperature analyses over land are primarily based on Td1. Here, I make a first quantitative assessment of the bias in the use of Td1 to estimate trends of mean air temperature using hourly air temperature observations at 5600 globally distributed weather stations from the 1970s to 2013. I find that the use of Td1 has a negligible impact on the global mean warming rate. However, the trend of Td1 has a substantial bias at regional and local scales, with a root mean square error of over 25% at 5°×5° grids. Therefore, caution should be taken when using mean air temperature datasets based on Td1 to examine spatial patterns of global warming.

  7. Estimation of Surface Air Temperature Over Central and Eastern Eurasia from MODIS Land Surface Temperature

    NASA Technical Reports Server (NTRS)

    Shen, Suhung; Leptoukh, Gregory G.

    2011-01-01

    Surface air temperature (T(sub a)) is a critical variable in the energy and water cycle of the Earth.atmosphere system and is a key input element for hydrology and land surface models. This is a preliminary study to evaluate estimation of T(sub a) from satellite remotely sensed land surface temperature (T(sub s)) by using MODIS-Terra data over two Eurasia regions: northern China and fUSSR. High correlations are observed in both regions between station-measured T(sub a) and MODIS T(sub s). The relationships between the maximum T(sub a) and daytime T(sub s) depend significantly on land cover types, but the minimum T(sub a) and nighttime T(sub s) have little dependence on the land cover types. The largest difference between maximum T(sub a) and daytime T(sub s) appears over the barren and sparsely vegetated area during the summer time. Using a linear regression method, the daily maximum T(sub a) were estimated from 1 km resolution MODIS T(sub s) under clear-sky conditions with coefficients calculated based on land cover types, while the minimum T(sub a) were estimated without considering land cover types. The uncertainty, mean absolute error (MAE), of the estimated maximum T(sub a) varies from 2.4 C over closed shrublands to 3.2 C over grasslands, and the MAE of the estimated minimum Ta is about 3.0 C.

  8. Emperor penguin body surfaces cool below air temperature.

    PubMed

    McCafferty, D J; Gilbert, C; Thierry, A-M; Currie, J; Le Maho, Y; Ancel, A

    2013-06-23

    Emperor penguins Aptenodytes forsteri are able to survive the harsh Antarctic climate because of specialized anatomical, physiological and behavioural adaptations for minimizing heat loss. Heat transfer theory predicts that metabolic heat loss in this species will mostly depend on radiative and convective cooling. To examine this, thermal imaging of emperor penguins was undertaken at the breeding colony of Pointe Géologie in Terre Adélie (66°40' S 140° 01' E), Antarctica in June 2008. During clear sky conditions, most outer surfaces of the body were colder than surrounding sub-zero air owing to radiative cooling. In these conditions, the feather surface will paradoxically gain heat by convection from surrounding air. However, owing to the low thermal conductivity of plumage any heat transfer to the skin surface will be negligible. Future thermal imaging studies are likely to yield further insights into the adaptations of this species to the Antarctic climate. PMID:23466479

  9. Emperor penguin body surfaces cool below air temperature

    PubMed Central

    McCafferty, D. J.; Gilbert, C.; Thierry, A.-M.; Currie, J.; Le Maho, Y.; Ancel, A.

    2013-01-01

    Emperor penguins Aptenodytes forsteri are able to survive the harsh Antarctic climate because of specialized anatomical, physiological and behavioural adaptations for minimizing heat loss. Heat transfer theory predicts that metabolic heat loss in this species will mostly depend on radiative and convective cooling. To examine this, thermal imaging of emperor penguins was undertaken at the breeding colony of Pointe Géologie in Terre Adélie (66°40′ S 140° 01′ E), Antarctica in June 2008. During clear sky conditions, most outer surfaces of the body were colder than surrounding sub-zero air owing to radiative cooling. In these conditions, the feather surface will paradoxically gain heat by convection from surrounding air. However, owing to the low thermal conductivity of plumage any heat transfer to the skin surface will be negligible. Future thermal imaging studies are likely to yield further insights into the adaptations of this species to the Antarctic climate. PMID:23466479

  10. Statistical modeling of urban air temperature distributions under different synoptic conditions

    NASA Astrophysics Data System (ADS)

    Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Hald, Cornelius; Hartz, Uwe; Jacobeit, Jucundus; Richter, Katja; Schneider, Alexandra; Wolf, Kathrin

    2015-04-01

    Within urban areas air temperature may vary distinctly between different locations. These intra-urban air temperature variations partly reach magnitudes that are relevant with respect to human thermal comfort. Therefore and furthermore taking into account potential interrelations with other health related environmental factors (e.g. air quality) it is important to estimate spatial patterns of intra-urban air temperature distributions that may be incorporated into urban planning processes. In this contribution we present an approach to estimate spatial temperature distributions in the urban area of Augsburg (Germany) by means of statistical modeling. At 36 locations in the urban area of Augsburg air temperatures are measured with high temporal resolution (4 min.) since December 2012. These 36 locations represent different typical urban land use characteristics in terms of varying percentage coverages of different land cover categories (e.g. impervious, built-up, vegetated). Percentage coverages of these land cover categories have been extracted from different sources (Open Street Map, European Urban Atlas, Urban Morphological Zones) for regular grids of varying size (50, 100, 200 meter horizonal resolution) for the urban area of Augsburg. It is well known from numerous studies that land use characteristics have a distinct influence on air temperature and as well other climatic variables at a certain location. Therefore air temperatures at the 36 locations are modeled utilizing land use characteristics (percentage coverages of land cover categories) as predictor variables in Stepwise Multiple Regression models and in Random Forest based model approaches. After model evaluation via cross-validation appropriate statistical models are applied to gridded land use data to derive spatial urban air temperature distributions. Varying models are tested and applied for different seasons and times of the day and also for different synoptic conditions (e.g. clear and calm

  11. Accuracy comparison of spatial interpolation methods for estimation of air temperatures in South Korea

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Shim, K.; Jung, M.; Kim, S.

    2013-12-01

    Because of complex terrain, micro- as well as meso-climate variability is extreme by locations in Korea. In particular, air temperature of agricultural fields are influenced by topographic features of the surroundings making accurate interpolation of regional meteorological data from point-measured data. This study was conducted to compare accuracy of a spatial interpolation method to estimate air temperature in Korean Peninsula with the rugged terrains in South Korea. Four spatial interpolation methods including Inverse Distance Weighting (IDW), Spline, Kriging and Cokriging were tested to estimate monthly air temperature of unobserved stations. Monthly measured data sets (minimum and maximum air temperature) from 456 automatic weather station (AWS) locations in South Korea were used to generate the gridded air temperature surface. Result of cross validation showed that using Exponential theoretical model produced a lower root mean square error (RMSE) than using Gaussian theoretical model in case of Kriging and Cokriging and Spline produced the lowest RMSE of spatial interpolation methods in both maximum and minimum air temperature estimation. In conclusion, Spline showed the best accuracy among the methods, but further experiments which reflect topography effects such as temperature lapse rate are necessary to improve the prediction.

  12. Preliminary verification of instantaneous air temperature estimation for clear sky conditions based on SEBAL

    NASA Astrophysics Data System (ADS)

    Zhu, Shanyou; Zhou, Chuxuan; Zhang, Guixin; Zhang, Hailong; Hua, Junwei

    2016-03-01

    Spatially distributed near surface air temperature at the height of 2 m is an important input parameter for the land surface models. It is of great significance in both theoretical research and practical applications to retrieve instantaneous air temperature data from remote sensing observations. An approach based on Surface Energy Balance Algorithm for Land (SEBAL) to retrieve air temperature under clear sky conditions is presented. Taking the meteorological measurement data at one station as the reference and remotely sensed data as the model input, the research estimates the air temperature by using an iterative computation. The method was applied to the area of Jiangsu province for nine scenes by using MODIS data products, as well as part of Fujian province, China based on four scenes of Landsat 8 imagery. Comparing the air temperature estimated from the proposed method with that of the meteorological station measurement, results show that the root mean square error is 1.7 and 2.6 °C at 1000 and 30 m spatial resolution respectively. Sensitivity analysis of influencing factors reveals that land surface temperature is the most sensitive to the estimation precision. Research results indicate that the method has great potentiality to be used to estimate instantaneous air temperature distribution under clear sky conditions.

  13. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  14. A method to derive the relationship between the annual and short-term air quality limits--analysis using the WHO Air Quality Guidelines for health protection.

    PubMed

    Lai, Hak-Kan; Hedley, Anthony J; Thach, Thuan-Quoc; Wong, Chit-Ming

    2013-09-01

    The World Health Organization (WHO) Air Quality Guidelines (AQG) were launched in 2006, but gaps remain in evidence on health impacts and relationships between short-term and annual AQG needed for health protection. We tested whether relationships between WHO short-term and annual AQG for particulates (PM10 and PM2.5) and nitrogen dioxide (NO2) are concordant worldwide and derived the annual limits for sulfur dioxide (SO2) and ozone (O3) based on the short-term AQG. We obtained air pollutant data over seven years (2004-2010) in seven cities from Asia-Pacific, North America and Europe. Based on probability distribution concept using maximum as the short-term limit and arithmetic mean as the annual limit, we developed a new method to derive limit value one from another in each paired limits for each pollutant with capability to account for allowable exceedances. We averaged the limit derived each year for each city, then used meta-analysis to pool the limit values in all cities. Pooled mean short-term limit for NO2 (140.5μg/m(3) [130.6-150.4]) was significantly lower than the WHO AQG of 200μg/m(3) while for PM10 (46.4μg/m(3) [95CI:42.1-50.7]) and PM2.5 (28.6μg/m(3) [24.5-32.6]) were not significantly different from the WHO AQG of 50 and 25μg/m(3) respectively. Pooled mean annual limits for SO2 and O3 were 4.6μg/m(3) [3.7-5.5] and 27.0μg/m(3) [21.7-32.2] respectively. Results were robust in various sensitivity analyses. The distribution relationships between the current WHO short-term and annual AQG are supported by empirical data from seven cities for PM10 and PM2.5, but not for NO2. The short-term AQG for NO2 should be lowered for concordance with the selected annual AQG for health protection. PMID:23792417

  15. A Review of the Thermodynamic, Transport, and Chemical Reaction Rate Properties of High-temperature Air

    NASA Technical Reports Server (NTRS)

    Hansen, C Frederick; Heims, Steve P

    1958-01-01

    Thermodynamic and transport properties of high temperature air, and the reaction rates for the important chemical processes which occur in air, are reviewed. Semiempirical, analytic expressions are presented for thermodynamic and transport properties of air. Examples are given illustrating the use of these properties to evaluate (1) equilibrium conditions following shock waves, (2) stagnation region heat flux to a blunt high-speed body, and (3) some chemical relaxation lengths in stagnation region flow.

  16. Ultraviolet Laser Raman Scattering for Temperature Measurement in Atmospheric Air Microdischarges

    NASA Astrophysics Data System (ADS)

    Caplinger, James; Adams, Steven; Williamson, James; Clark, Jerry

    2011-10-01

    Vibrational Raman scattering for temperature measurement within a dc microdischarge in atmospheric pressure air has been investigated using a pulsed ultraviolet laser. The Raman signal analysis method involved monitoring Q-branch signals originating from multiple N2(X) vibrational states populated in the microdischarge. The translational temperature of N2(X) in the microdischarge was calculated using the total Raman signal intensity calibrated with room temperature air. Also, the distribution of Q-branch intensities among vibrational states allowed for direct measurement of the vibrational temperature of N2(X). Raman scattering results are compared to passive optical emission spectral analyses of the N2 second positive system from which the rotational and vibrational temperatures of the N2(C) excited state were also calculated. A comparison of the N2(X) and N2(C) temperatures derived from Raman scattering and emission spectroscopy, respectively, is presented. This work was supported by the Air Force Office of Scientific Research.

  17. The characteristics of high temperature air combustion and its practical application to high performance industrial furnace

    SciTech Connect

    Sugiyama, Shunichi; Suzukawa, Yutaka; Hino, Yoshimichi

    1999-07-01

    An experimental regenerative continuous slab reheat furnace was used for the data acquisition of high temperature air combustion. Obtainable preheated air temperature, gas temperature distribution of combustion field, NOx concentration in waste gas, heating pattern, furnace height etc were studied for this purpose. Main results were (1) preheated air temperature close to furnace temperature can be obtained, (2) gas temperature distribution is relatively uniform in main combustion field, (3) NOx concentration in waste gas is significantly reduced, (4) there exists the appropriate combustion capacity of a burner for every furnace width, (5) the optimum furnace height for regenerative continuous slab reheat furnace from the thermal efficiency point of view is lower than the convention one by about 0.5m.

  18. The influence of air temperature inversions on snowmelt and glacier mass-balance simulations, Ammassalik island, SE Greenland

    SciTech Connect

    Mernild, Sebastian Haugard; Liston, Glen

    2009-01-01

    In many applications, a realistic description of air temperature inversions is essential for accurate snow and glacier ice melt, and glacier mass-balance simulations. A physically based snow-evolution modeling system (SnowModel) was used to simulate eight years (1998/99 to 2005/06) of snow accumulation and snow and glacier ice ablation from numerous small coastal marginal glaciers on the SW-part of Ammassalik Island in SE Greenland. These glaciers are regularly influenced by inversions and sea breezes associated with the adjacent relatively low temperature and frequently ice-choked fjords and ocean. To account for the influence of these inversions on the spatiotemporal variation of air temperature and snow and glacier melt rates, temperature inversion routines were added to MircoMet, the meteorological distribution sub-model used in SnowModel. The inversions were observed and modeled to occur during 84% of the simulation period. Modeled inversions were defined not to occur during days with strong winds and high precipitation rates due to the potential of inversion break-up. Field observations showed inversions to extend from sea level to approximately 300 m a.s.l., and this inversion level was prescribed in the model simulations. Simulations with and without the inversion routines were compared. The inversion model produced air temperature distributions with warmer lower elevation areas and cooler higher elevation areas than without inversion routines due to the use of cold sea-breeze base temperature data from underneath the inversion. This yielded an up to 2 weeks earlier snowmelt in the lower areas and up to 1 to 3 weeks later snowmelt in the higher elevation areas of the simulation domain. Averaged mean annual modeled surface mass-balance for all glaciers (mainly located above the inversion layer) was -720 {+-} 620 mm w.eq. y{sup -1} for inversion simulations, and -880 {+-} 620 mm w.eq. y{sup -1} without the inversion routines, a difference of 160 mm w.eq. y

  19. Temperature and Humidity Independent Control Research on Ground Source Heat Pump Air Conditioning System

    NASA Astrophysics Data System (ADS)

    Chen, G.; Wang, L. L.

    Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.

  20. Biodiesel and Cold Temperature Effect on Speciated Mobile Source Air Toxics from Modern Diesel Trucks

    EPA Science Inventory

    Speciated volatile organic compounds (VOCs) with a particular focus on mobile source air toxics (MSATs) were measured in diesel exhaust from three heavy-duty trucks equipped with modern aftertreatment technologies. Emissions testing was conducted on a temperature controlled chass...

  1. Biodiesel and Cold Temperature Effects on Speciated Mobile Source Air Toxics from Modern Diesel Trucks

    EPA Science Inventory

    Speciated volatile organic compounds (VOCs) with a particular focus on mobile source air toxics (MSATs) were measured in diesel exhaust from three heavy-duty trucks equipped with modern aftertreatment technologies. Emissions testing was conducted on a temperature controlled chass...

  2. Air stability of low-temperature dehydrogenation of Pd-decorated Mg blades.

    PubMed

    Liu, Yu; Wang, Gwo-Ching

    2012-01-20

    We demonstrated that Pd-decorated Mg blades are air-stable for hydrogen storage with a low desorption temperature of 373 K. Pd-catalyst-decorated Mg blades were prepared by 64° oblique incident angle thermal deposition on a rotatable substrate with the rotation axis perpendicular to the substrate. The hydrogen desorption from Pd-decorated Mg blades was performed and recorded by temperature-programmed desorption (TPD) for repeated hydrogenation–dehydrogenation cycles. The near-surface structural and compositional changes were characterized in situ by reflection high energy electron diffraction (RHEED). The Mg blades were intentionally exposed to air at elevated temperatures (333 or 358 K) between certain cycles. It was found that the degradation of the storage capacity was affected weakly by the air exposure at moderate temperatures. The kinetics of the hydrogen desorption was sensitive to air exposure but recoverable through a replenishment of fresh catalyst Pd on the surface of the oxidized Mg blades. PMID:22166731

  3. Transport properties of high-temperature air in a magnetic field

    SciTech Connect

    Bruno, D.; Capitelli, M.; Catalfamo, C.; Giordano, D.

    2011-01-15

    Transport properties of equilibrium air plasmas in a magnetic field are calculated with the Chapman-Enskog method. The range considered for the temperature is [50-50 000] K and for the magnetic induction is [0-300] T.

  4. Apparatus and method for generating large mass flow of high temperature air at hypersonic speeds

    NASA Technical Reports Server (NTRS)

    Sabol, A. P.; Stewart, R. B. (Inventor)

    1973-01-01

    High temperature, high mass air flow and a high Reynolds number test air flow in the Mach number 8-10 regime of adequate test flow duration is attained by pressurizing a ceramic-lined storage tank with air to a pressure of about 100 to 200 atmospheres. The air is heated to temperatures of 7,000 to 8,000 R prior to introduction into the tank by passing the air over an electric arc heater means. The air cools to 5,500 to 6,000 R while in the tank. A decomposable gas such as nitrous oxide or a combustible gas such as propane is injected into the tank after pressurization and the heated pressurized air in the tank is rapidly released through a Mach number 8-10 nozzle. The injected gas medium upon contact with the heated pressurized air effects an exothermic reaction which maintains the pressure and temperature of the pressurized air during the rapid release.

  5. Improving forecast skill by assimilation of quality-controlled AIRS temperature retrievals under partially cloudy conditions

    NASA Astrophysics Data System (ADS)

    Reale, O.; Susskind, J.; Rosenberg, R.; Brin, E.; Liu, E.; Riishojgaard, L. P.; Terry, J.; Jusem, J. C.

    2008-04-01

    The National Aeronautics and Space Administration (NASA) Atmospheric Infrared Sounder (AIRS) on board the Aqua satellite is now recognized as an important contributor towards the improvement of weather forecasts. At this time only a small fraction of the total data produced by AIRS is being used by operational weather systems. In fact, in addition to effects of thinning and quality control, the only AIRS data assimilated are radiance observations of channels unaffected by clouds. Observations in mid-lower tropospheric sounding AIRS channels are assimilated primarily under completely clear-sky conditions, thus imposing a very severe limitation on the horizontal distribution of the AIRS-derived information. In this work it is shown that the ability to derive accurate temperature profiles from AIRS observations in partially cloud-contaminated areas can be utilized to further improve the impact of AIRS observations in a global model and forecasting system. The analyses produced by assimilating AIRS temperature profiles obtained under partial cloud cover result in a substantially colder representation of the northern hemisphere lower midtroposphere at higher latitudes. This temperature difference has a strong impact, through hydrostatic adjustment, in the midtropospheric geopotential heights, which causes a different representation of the polar vortex especially over northeastern Siberia and Alaska. The AIRS-induced anomaly propagates through the model's dynamics producing improved 5-day forecasts.

  6. Improving Forecast Skill by Assimilation of Quality-controlled AIRS Temperature Retrievals under Partially Cloudy Conditions

    NASA Technical Reports Server (NTRS)

    Reale, O.; Susskind, J.; Rosenberg, R.; Brin, E.; Riishojgaard, L.; Liu, E.; Terry, J.; Jusem, J. C.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) Atmospheric Infrared Sounder (AIRS) on board the Aqua satellite has been long recognized as an important contributor towards the improvement of weather forecasts. At this time only a small fraction of the total data produced by AIRS is being used by operational weather systems. In fact, in addition to effects of thinning and quality control, the only AIRS data assimilated are radiance observations of channels unaffected by clouds. Observations in mid-lower tropospheric sounding AIRS channels are assimilated primarily under completely clear-sky conditions, thus imposing a very severe limitation on the horizontal distribution of the AIRS-derived information. In this work it is shown that the ability to derive accurate temperature profiles from AIRS observations in partially cloud-contaminated areas can be utilized to further improve the impact of AIRS observations in a global model and forecasting system. The analyses produced by assimilating AIRS temperature profiles obtained under partial cloud cover result in a substantially colder representation of the northern hemisphere lower midtroposphere at higher latitudes. This temperature difference has a strong impact, through hydrostatic adjustment, in the midtropospheric geopotential heights, which causes a different representation of the polar vortex especially over northeastern Siberia and Alaska. The AIRS-induced anomaly propagates through the model's dynamics producing improved 5-day forecasts.

  7. Pan-Arctic linkages between snow accumulation and growing-season air temperature, soil moisture and vegetation

    NASA Astrophysics Data System (ADS)

    Luus, K. A.; Gel, Y.; Lin, J. C.; Kelly, R. E. J.; Duguay, C. R.

    2013-11-01

    Arctic field studies have indicated that the air temperature, soil moisture and vegetation at a site influence the quantity of snow accumulated, and that snow accumulation can alter growing-season soil moisture and vegetation. Climate change is predicted to bring about warmer air temperatures, greater snow accumulation and northward movements of the shrub and tree lines. Understanding the responses of northern environments to changes in snow and growing-season land surface characteristics requires: (1) insights into the present-day linkages between snow and growing-season land surface characteristics; and (2) the ability to continue to monitor these associations over time across the vast pan-Arctic. The objective of this study was therefore to examine the pan-Arctic (north of 60° N) linkages between two temporally distinct data products created from AMSR-E satellite passive microwave observations: GlobSnow snow water equivalent (SWE), and NTSG growing-season AMSR-E Land Parameters (air temperature, soil moisture and vegetation transmissivity). Due to the complex and interconnected nature of processes determining snow and growing-season land surface characteristics, these associations were analyzed using the modern nonparametric technique of alternating conditional expectations (ACE), as this approach does not impose a predefined analytic form. Findings indicate that regions with lower vegetation transmissivity (more biomass) at the start and end of the growing season tend to accumulate less snow at the start and end of the snow season, possibly due to interception and sublimation. Warmer air temperatures at the start and end of the growing season were associated with diminished snow accumulation at the start and end of the snow season. High latitude sites with warmer mean annual growing-season temperatures tended to accumulate more snow, probably due to the greater availability of water vapor for snow season precipitation at warmer locations. Regions with drier

  8. Assessing the Potential of the AIRS Retrieved Surface Temperature for 6-Hour Average Temperature Forecast in River Forecast Centers

    NASA Astrophysics Data System (ADS)

    Ding, F.; Theobald, M.; Vollmer, B.; Savtchenko, A. K.; Hearty, T. J.; Esfandiari, A. E.

    2012-12-01

    Producing timely and accurate water forecast and information is the mission of National Weather Service River Forecast Centers (NWS RFCs) of National Oceanic and Atmospheric Administration (NOAA). The river forecast system in RFCs requires average surface temperature in the fixed 6-hour period 000-0600, 0600-1200, 1200-1800, and 1200-0000 UTC. The current logic of RFC temperature forecast relies on ingest of point values of daytime maximum and nighttime minimum temperature. Meanwhile, the mean temperature for the 6-hour period is estimated from a weighted average of daytime maximum and nighttime minimum temperature. The Atmospheric Infrared Sounder (AIRS) in the first high spectral resolution infrared sounder on board the Aqua satellite which was launched in May 2002 and follows a Sun-synchronous polar orbit. It is aimed to produce high resolution atmospheric profile and surface atmospheric parameters. As Aqua crosses the equator at about 1330 and 0130 local time, the AIRS retrieved surface temperature may represent daytime maximum and nighttime minimum value. Comparing to point observation from surface weather stations which are often sparse over the less-populated area and are unevenly distributed, satellite may obtain better area averaged observation. This test study assesses the potential of using AIRS retrieved surface temperature to forecast 6-hour average temperature for NWS RFCs. The California Nevada RFC is selected due to the poor coverage of surface observation in the mountainous region and spring snow melting. The study focuses on the March to May spring season when water from snowpack melting often plays important role in flood. AIRS retrieved temperature and surface weather station data set will be used to derive statistical weighting coefficient for 6-hour average temperature forecast. The resulting forecast biases and errors will be the main indicators of the potential usage. All study results will be presented in the meeting.

  9. Rate constants for chemical reactions in high-temperature nonequilibrium air

    NASA Technical Reports Server (NTRS)

    Jaffe, R. L.

    1986-01-01

    In the nonequilibrium atmospheric chemistry regime that will be encountered by the proposed Aeroassisted Orbital Transfer Vehicle in the upper atmosphere, where air density is too low for thermal and chemical equilibrium to be maintained, the detailed high temperature air chemistry plays a critical role in defining radiative and convective heating loads. Although vibrational and electronic temperatures remain low (less than 15,000 K), rotational and translational temperatures may reach 50,000 K. Attention is presently given to the effects of multiple temperatures on the magnitudes of various chemical reaction rate constants, for the cases of both bimolecular exchange reactions and collisional excitation and dissociation reactions.

  10. Repeat temperature measurements in boreholes from northwestern Utah link ground and air temperature changes at the decadal time scale

    NASA Astrophysics Data System (ADS)

    Davis, Michael G.; Harris, Robert N.; Chapman, David S.

    2010-05-01

    Borehole temperature profiles provide a record of ground surface temperature (GST) change at the decadal to centennial time scale. GST histories reconstructed from boreholes are particularly useful in climate reconstruction if changes in GST and surface air temperature (SAT) are effectively coupled at decadal and longer time periods and it can be shown that borehole temperatures respond faithfully to surface temperature changes. We test these assumptions using three boreholes in northwestern Utah that have been repeatedly logged for temperature over a time span of 29 years. We report 13 temperature-depth logs at the Emigrant Pass Observatory borehole GC-1, eight at borehole SI-1 and five at borehole DM-1, acquired between 1978 and 2007. Systematic subsurface temperature changes of up to 0.6°C are observed over this time span in the upper sections of the boreholes; below approximately 100 m any temperature transients are within observational noise. We difference the temperature logs to highlight subsurface transients and to remove any ambiguity resulting from steady state source of curvature. Synthetic temperature profiles computed from SAT data at nearby meteorological stations reproduce both the amplitude and pattern of the transient temperature observations, fitting the observations to within 0.03°C or better. This observational confirmation of the strong coupling between surface temperature change and borehole temperature transients lends further support to the use of borehole temperatures to complement SAT and multiproxy reconstructions of climate change.

  11. Air quality and temperature effects on exercise-induced bronchoconstriction.

    PubMed

    Rundell, Kenneth W; Anderson, Sandra D; Sue-Chu, Malcolm; Bougault, Valerie; Boulet, Louis-Philippe

    2015-04-01

    Exercise-induced bronchoconstriction (EIB) is exaggerated constriction of the airways usually soon after cessation of exercise. This is most often a response to airway dehydration in the presence of airway inflammation in a person with a responsive bronchial smooth muscle. Severity is related to water content of inspired air and level of ventilation achieved and sustained. Repetitive hyperpnea of dry air during training is associated with airway inflammatory changes and remodeling. A response during exercise that is related to pollution or allergen is considered EIB. Ozone and particulate matter are the most widespread pollutants of concern for the exercising population; chronic exposure can lead to new-onset asthma and EIB. Freshly generated emissions particulate matter less than 100 nm is most harmful. Evidence for acute and long-term effects from exercise while inhaling high levels of ozone and/or particulate matter exists. Much evidence supports a relationship between development of airway disorders and exercise in the chlorinated pool. Swimmers typically do not respond in the pool; however, a large percentage responds to a dry air exercise challenge. Studies support oxidative stress mediated pathology for pollutants and a more severe acute response occurs in the asthmatic. Winter sport athletes and swimmers have a higher prevalence of EIB, asthma and airway remodeling than other athletes and the general population. Because of fossil fuel powered ice resurfacers in ice rinks, ice rink athletes have shown high rates of EIB and asthma. For the athlete training in the urban environment, training during low traffic hours and in low traffic areas is suggested. PMID:25880506

  12. The temperature of inspired air influences respiratory water loss in young lambs.

    PubMed

    Riesenfeld, T; Hammarlund, K; Norsted, T; Sedin, G

    1994-01-01

    The temperature of inspired air influences respiratory water loss (RWL) in young lambs. Water loss from the airways, oxygen consumption and carbon dioxide production were measured using an open flow-through system with a mass spectrometer, specially equipped with a water channel, for gas analysis. Measurements were made in 9 newborn lambs at 3 different inspired air temperatures keeping all other environmental factors stable, including the ambient air temperature. The water content of the inspired air was also kept constant. RWL was found to be 9.9 +/- 3.9 (SD) mg/kg/min when the temperature of the inspired air was 30 degrees C and its humidity 30%. At 40 degrees C this loss increased to 11.5 +/- 3.6 mg/kg/min, and at about 60 degrees C it increased further to 26.0 +/- 8.2 mg/kg/min. The oxygen consumption was 10.0 +/- 0.8 (SD) ml/kg/min at 30 degrees C and 10.4 +/- 2.0 ml/kg/min at 60 degrees C, a change which is not significant. Thus RWL is influenced by the temperature of the inspired air, with greater loss at higher temperatures. PMID:8054401

  13. Simulating Tree and Topography Effects on Urban Air temperature and Humidity

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Endreny, T. A.; Nowak, D. J.; Kroll, C.; Heisler, G. M.

    2012-12-01

    Microclimate, especially air temperature and humidity, significantly affect human thermal comfort, ecosystem services, and building energy use. Air temperature and humidity measurements are generally recorded at fixed-location meteorology stations, which do not represent the spatial variations encountered in these parameters across the landscape. We developed a spatial air temperature and humidity model to simulate local air temperature and humidity over a region where the mesoscale climate is presumed homogeneous. The model assumes that under the same mesoscale climate, microclimate is modified by local topography and land cover, which are two critical factors determining the absorbed solar radiation and the partitioning of sensible and latent heat. Therefore, the difference in microclimates among local clusters can be determined by the differences in local topography and land cover. Given a reference site where the meteorological data are collected, the microclimate of any other local cluster can be obtained by comparing the topography and land cover of the reference site and the local cluster. The model was tested at 11 locations in Syracuse, NY, where the hourly air temperature and humidity were measured from July 15, 2010 through September 15, 2010. The simulation results showed the model has high efficiency in estimating local cluster air temperature and humidity. The model can be applied on strategic urban reforestation designs, urban heat island mitigation, climate change mitigation and adaptation, and ecosystem interaction research.

  14. Near-surface air temperature and snow skin temperature comparison from CREST-SAFE station data with MODIS land surface temperature data

    NASA Astrophysics Data System (ADS)

    Pérez Díaz, C. L.; Lakhankar, T.; Romanov, P.; Muñoz, J.; Khanbilvardi, R.; Yu, Y.

    2015-08-01

    Land Surface Temperature (LST) is a key variable (commonly studied to understand the hydrological cycle) that helps drive the energy balance and water exchange between the Earth's surface and its atmosphere. One observable constituent of much importance in the land surface water balance model is snow. Snow cover plays a critical role in the regional to global scale hydrological cycle because rain-on-snow with warm air temperatures accelerates rapid snow-melt, which is responsible for the majority of the spring floods. Accurate information on near-surface air temperature (T-air) and snow skin temperature (T-skin) helps us comprehend the energy and water balances in the Earth's hydrological cycle. T-skin is critical in estimating latent and sensible heat fluxes over snow covered areas because incoming and outgoing radiation fluxes from the snow mass and the air temperature above make it different from the average snowpack temperature. This study investigates the correlation between MODerate resolution Imaging Spectroradiometer (MODIS) LST data and observed T-air and T-skin data from NOAA-CREST-Snow Analysis and Field Experiment (CREST-SAFE) for the winters of 2013 and 2014. LST satellite validation is imperative because high-latitude regions are significantly affected by climate warming and there is a need to aid existing meteorological station networks with the spatially continuous measurements provided by satellites. Results indicate that near-surface air temperature correlates better than snow skin temperature with MODIS LST data. Additional findings show that there is a negative trend demonstrating that the air minus snow skin temperature difference is inversely proportional to cloud cover. To a lesser extent, it will be examined whether the surface properties at the site are representative for the LST properties within the instrument field of view.

  15. A Comprehensive Analysis of AIRS Near Surface Air Temperature and Water Vapor Over Land and Tropical Ocean

    NASA Astrophysics Data System (ADS)

    Dang, H. V. T.; Lambrigtsen, B.; Manning, E. M.; Fetzer, E. J.; Wong, S.; Teixeira, J.

    2015-12-01

    Version 6 (V6) of the Atmospheric Infrared Sounder's (AIRS) combined infrared and microwave (IR+MW) retrieval of near surface air temperature (NSAT) and water vapor (NSWV) is validated over the United States with the densely populated MESONET data. MESONET data is a collection of surface/near surface meteorological data from many federal and state agencies. The ones used for this analysis are measured from instruments maintained by the National Weather Service (NWS), the Federal Aviation Administration (FAA), and the Interagency Remote Automatic Weather Stations (RAWS), resulting in a little more than four thousand locations throughout the US. Over the Tropical oceans, NSAT and NSWV are compared to a network of moored buoys from the Tropical Atmosphere Ocean/Triangle Trans-Ocean Buoy Network (TAO/TRITON), and the Pilot Research Moored Array in the Tropical Atlantic (PIRATA). With the analysis of AIRS surface and near surface products over ocean, we glean information on how retrieval of NSAT and NSWV over land can be improved and why it needs some adjustments. We also compare AIRS initial guess of near surface products that are trained on fifty days of ECMWF along with AIRS calibrated radiances, to ECMWF analysis data. The comparison is done to show the differing characteristics of AIRS initial guesses from ECMWF.

  16. Surface air temperature anomalies for the Northern Hemisphere: The Russian dataset

    SciTech Connect

    Robock, A.; Borzenkova, I.I.; Gurza, G.V.; Vinnikov, K.Ya.

    1988-03-01

    The existence of a Russian surface temperature dataset became known to Western scientists when Budyko (1969) showed the secular variation of temperature and direct radiation for the Northern Hemisphere. His results were derived from maps of monthly mean surface air temperature anomalies compiled at the Main Geophysical Observatory. These maps covered the period 1881 to 1960 and were prepared for the purpose of monthly and seasonal forecasting, with a goal of finding patterns in monthly departures from normal temperatures.

  17. Duration study for heating and air-conditioning design temperatures

    SciTech Connect

    Snelling, H.J.

    1985-01-01

    Recently, abnormally cold winters and hot summers have generated interest in the duration of time that design temperature values have been equaled or exceeded. ETAC's Engineering Meteorology Section did a pilot study to examine temperature records for several military installations and give some insight into durations that may occur. The authors chose sites to represent different climatic regimes. For each site, the authors generated statistics on the number of occurrences of durations of one, two, three ... up to eight hours for each of the design temperature values (1%, 2 1/2%, and 5% temperatures for the summer months; 99% and 97 1/2% for winter months). The authors also made a study of the longest duration of each design value. The authors used the latest available 15 consecutive years of temperature data for all sites. The authors also made a comparison of data for the 15-year period of record (POR) versus data for the total available POR for some of the sites. Results were inconclusive and indicate that more study is needed.

  18. BOREAS RSS-17 Stem, Soil, and Air Temperature Data

    NASA Technical Reports Server (NTRS)

    Zimmerman, Reiner; McDonald, Kyle C.; Way, JoBea; Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The BOREAS RSS-17 team collected several data sets in support of its research in monitoring and analyzing environmental and phenological states using radar data. This data set consists of tree bole and soil temperature measurements from various BOREAS flux tower sites. Temperatures were measured with thermistors implanted in the hydroconductive tissue of the trunks of several trees at each site and at various depths in the soil. Data were stored on a data logger at intervals of either 1 or 2 hours. The majority of the data were acquired between early 1994 and early 1995. The primary product of this data set is the diurnal stem temperature measurements acquired for selected trees at five BOREAS tower sites. The data are provided in tabular ASCII format. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  19. Mean annual temperatures of mid-latitude regions derived from stable hydrogen isotopes of wood lignin

    NASA Astrophysics Data System (ADS)

    Anhäuser, Tobias; Greule, Markus; Bowen, Gabriel J.; Keppler, Frank

    2016-04-01

    Tree rings are widely used climate archives providing annual resolutions on centennial to millennial timescales. Besides plant physiological parameters such as tree-ring width or maximum latewood density, stable isotope compositions (expressed as δ values) complement or even broaden the potential of the climate archive tree rings. A considerable wood constituent are ether-bonded methoxyl groups as part of lignin which can be used for stable hydrogen isotope studies. The δ²H value of the lignin methoxyl groups reflects the δ²H value of the tree source water as a result of a large uniform fractionation. Hence, this relation can be used to infer δ²H values of precipitation which are in temperate regions primarily controlled by temperature. Here, we measured δ²H values of lignin methoxyl groups (n = 111) of tree rings from various species collected along a ~3500 km north-south transect across Europe with mean annual temperatures (MAT) ranging from ‑4 to +17 °C. We found a significant linear correlation between δ²H values of the lignin methoxyl groups and MAT (R² = 0.81, p < 0.01). We used this relationship to predict MATs from randomly collected wood samples and found general agreement between predicted and observed MATs for the mid-latitudes on a global scale. Thus our results indicate that δ²H values of lignin methoxyl groups are a promising tool for mid-latitude temperature reconstruction of the Holocene.

  20. Data Assimilation Experiments Using Quality Controlled AIRS Version 5 Temperature Soundings

    NASA Technical Reports Server (NTRS)

    Susskind, Joel

    2009-01-01

    The AIRS Science Team Version 5 retrieval algorithm has been finalized and is now operational at the Goddard DAAC in the processing (and reprocessing) of all AIRS data. The AIRS Science Team Version 5 retrieval algorithm contains a number of significant improvements over Version 4. Two very significant improvements are described briefly below. 1) The AIRS Science Team Radiative Transfer Algorithm (RTA) has now been upgraded to accurately account for effects of non-local thermodynamic equilibrium on the AIRS observations. This allows for use of AIRS observations in the entire 4.3 micron CO2 absorption band in the retrieval algorithm during both day and night. Following theoretical considerations, tropospheric temperature profile information is obtained almost exclusively from clear column radiances in the 4.3 micron CO2 band in the AIRS Version 5 temperature profile retrieval step. These clear column radiances are a derived product that are indicative of radiances AIRS channels would have seen if the field of view were completely clear. Clear column radiances for all channels are determined using tropospheric sounding 15 micron CO2 observations. This approach allows for the generation of accurate values of clear column radiances and T(p) under most cloud conditions. 2) Another very significant improvement in Version 5 is the ability to generate accurate case-by-case, level-by-level error estimates for the atmospheric temperature profile, as well as for channel-by-channel clear column radiances. These error estimates are used for quality control of the retrieved products. Based on error estimate thresholds, each temperature profiles is assigned a characteristic pressure, pg, down to which the profile is characterized as good for use for data assimilation purposes. We have conducted forecast impact experiments assimilating AIRS quality controlled temperature profiles using the NASA GEOS-5 data assimilation system, consisting of the NCEP GSI analysis coupled with the

  1. Spatial Disaggregation of the 0.25-degree GLDAS Air Temperature Dataset to 30-arcsec Resolution

    NASA Astrophysics Data System (ADS)

    Ji, L.; Senay, G. B.; Verdin, J. P.; Velpuri, N. M.

    2015-12-01

    Air temperature is a key input variable in ecological and hydrological models for simulating the hydrological cycle and water budget. Several global reanalysis products have been developed at different organizations, which provide gridded air temperature datasets at resolutions ranging from 0.25º to 2.5º (or 27.8 - 278.3 km at the equator). However, gridded air temperature products at a high-resolution (≤1 km) are available only for limited areas of the world. To meet the needs for global eco-hydrological modeling, we aim to produce a continuous daily air temperature datasets at 1-km resolution for the global coverage. In this study, we developed a technique that spatially disaggregates the 0.25º Global Land Data Assimilation System (GLDAS) daily air temperature data to 30-arcsec (0.928 km at the equator) resolution by integrating the GLDAS data with the 30-arcsec WorldClim 1950 - 2000 monthly normal air temperature data. The method was tested using the GLDAS and Worldclim maximum and minimum air temperature datasets from 2002 and 2010 for the conterminous Unites States and Africa. The 30-arcsec disaggregated GLDAS (GLDASd) air temperature dataset retains the mean values of the original GLDAS data, while adding spatial variabilities inherited from the Worldclim data. A great improvement in GLDAS disaggregation is shown in mountain areas where complex terrain features have strong impact on temperature. We validated the disaggregation method by comparing the GLDASd product with daily meteorological observations archived by the Global Historical Climatology Network (GHCN) and the Global Surface Summary of the Day (GSOD) datasets. Additionally, the 30-arcsec TopoWX daily air temperature product was used to compare with the GLDASd data for the conterminous United States. The proposed data disaggregation method provides a convenient and efficient tool for generating a global high-resolution air temperature dataset, which will be beneficial to global eco

  2. Hypothetical air ingress scenarios in advanced modular high temperature gas cooled reactors

    SciTech Connect

    Kroeger, P.G.

    1988-01-01

    Considering an extremely hypothetical scenario of complete cross duct failure and unlimited air supply into the reactor vessel of a modular high temperature gas cooled ractor, it is found that the potential air inflow remains limited due to the high friction pressure drop through the active core. All incoming air will be oxidized to CO and some local external burning would be temporarily possible in such a scenario. The accident would have to continue with unlimited air supply for hundreds of hours before the core structural integrity would be jeopardized.

  3. Floatabilities of treated coal in water at room temperature. Annual topical report, September 1992--August 1993

    SciTech Connect

    Kwon, K.C.; Rohrer, R.L.; Lai, R.W.; Finseth, D.H.

    1993-12-31

    This report contains a research paper entitled ``Floatability of Treated Coal in Water at Room Temperature.`` Experimental data on equilibrium adsorption loadings of probe compounds on coal, and flotation of raw coals as well as treated coal were obtained, using Illinois No. 6 coal (PSOC-1539), Adaville No. 1 coal (PSOC-1544), Wyodak coal (PSOC-1545) and Pittsburgh No. 8 coal (PSOC-1549). The raw data of this Annual Topical Report are also available in the Quarterly Progress Report for the period April--June 1993 and the Quarterly Progress Report July--September 1993.

  4. Comparison of Vertical Soundings and Sidewall Air Temperature Measurements in a Small Alpine Basin

    SciTech Connect

    Whiteman, Charles D.; Eisenbach, Stefan; Pospichal, Bernhard; Steinacker, Reinhold

    2004-11-01

    Tethered balloon soundings from two sites on the floor of a 1-km diameter limestone sinkhole in the Eastern Alps are compared with pseudo-vertical temperature ‘soundings’ from three lines of temperature data loggers on the basin’s northwest, southwest and southeast sidewalls. Under stable nighttime conditions with low background winds, the pseudo-vertical profiles from all three lines were good proxies for free air temperature soundings over the basin center, with a mean nighttime cold temperature bias of about 0.4°C and a standard deviation of 0.4°C. Cold biases were highest in the upper basin where relatively warm air subsides to replace air that spills out of the basin through the lowest altitude saddle. On a windy night, standard deviations increased to 1 - 2°C. After sunrise, the varying exposures of the data loggers to sunlight made the pseudo-vertical profiles less useful as proxies for free air soundings. The good correspondence between sidewall and free air temperatures during high static stability conditions suggests that sidewall soundings will prove useful in monitoring temperatures and vertical temperature gradients in the sinkhole. The sidewall soundings can produce more frequent profiles at less cost than tethersondes or rawinsondes, and provide valuable advantages for some types of meteorological analyses.

  5. Summertime Temperatures in Buildings Without Air-Conditioning.

    ERIC Educational Resources Information Center

    Loudon, A. G.

    Many modern buildings become uncomfortably warm during sunny spells in the summer, and until recently there was no simple, reliable method of assessing at the design stage whether a building would become overheated. This paper describes a method of calculating summertime temperatures which was developed at the Building Research Station, and gives…

  6. Measured Performance of a Low Temperature Air Source Heat Pump

    SciTech Connect

    Johnson, R. K.

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor 'boosted heat pump' technology. The Low Temperature Heat Pumpsystem operates with four increasing levels of capacity (heat output) as the outdoor temperature drops. The system was shown to select capacity correctly, supplying the appropriate amount of heat to the house across the full range of outdoor temperatures. The system's Coefficient of Performance (Seasonal COP, or SCOP) over two entire winters was calculated, based on measured data, to be 3.29over the first winter and 2.68 over the second winter. A second seasonal efficiency calculation by a different method yielded a SCOP of 2.78 for the first winter and 2.83 for the second winter. This second seasonal efficiency calculation was determined by comparing measured heat pump energy use to the in situ energy use with resistance heat alone. This method is the ratio of the slopes of thedaily energy use load lines.

  7. Characteristics of Gaseous Diffusion Flames with High Temperature Combustion Air in Microgravity

    NASA Technical Reports Server (NTRS)

    Ghaderi, M.; Gupta, A. K.

    2003-01-01

    The characteristics of gaseous diffusion flames have been obtained using high temperature combustion air under microgravity conditions. The time resolved flame images under free fall microgravity conditions were obtained from the video images obtained. The tests results reported here were conducted using propane as the fuel and about 1000 C combustion air. The burner included a 0.686 mm diameter central fuel jet injected into the surrounding high temperature combustion air. The fuel jet exit Reynolds number was 63. Several measurements were taken at different air preheats and fuel jet exit Reynolds number. The resulting hybrid color flame was found to be blue at the base of the flame followed by a yellow color flame. The length and width of flame during the entire free fall conditions has been examined. Also the relative flame length and width for blue and yellow portion of the flame has been examined under microgravity conditions. The results show that the flame length decreases and width increases with high air preheats in microgravity condition. In microgravity conditions the flame length is larger with normal temperature combustion air than high temperature air.

  8. Spectroscopic temperature measurements of air breakdown plasma using a 110 GHz megawatt gyrotron beam

    SciTech Connect

    Hummelt, J. S.; Shapiro, M. A.; Temkin, R. J.

    2012-12-15

    Temperature measurements are presented of a non-equilibrium air breakdown plasma using optical emission spectroscopy. A plasma is created with a focused 110 GHz 3 {mu}s pulse gyrotron beam in air that produces power fluxes exceeding 1 MW/cm{sup 2}. Rotational and vibrational temperatures are spectroscopically measured over a pressure range of 1-100 Torr as the gyrotron power is varied above threshold. The temperature dependence on microwave field as well as pressure is examined. Rotational temperature measurements of the plasma reveal gas temperatures in the range of 300-500 K and vibrational temperatures in the range of 4200-6200 K. The vibrational and rotational temperatures increase slowly with increasing applied microwave field over the range of microwave fields investigated.

  9. Apparatus and Method for Measuring Air Temperature Ahead of an Aircraft for Controlling a Variable Inlet/Engine Assembly

    NASA Technical Reports Server (NTRS)

    Gary, Bruce L. (Inventor)

    2001-01-01

    The apparatus and method employ remote sensing to measure the air temperature a sufficient distance ahead of the aircraft to allow time for a variable inlet/engine assembly to be reconfigured in response to the measured temperature, to avoid inlet unstart and/or engine compressor stall. In one embodiment, the apparatus of the invention has a remote sensor for measuring at least one air temperature ahead of the vehicle and an inlet control system for varying the inlet. The remote sensor determines a change in temperature value using at least one temperature measurement and prior temperature measurements corresponding to the location of the aircraft. The control system uses the change in air temperature value to vary the inlet configuration to maintain the position of the shock wave during the arrival of the measured air in the inlet. In one embodiment, the method of the invention includes measuring at least one air temperature ahead of the vehicle, determining an air temperature at the vehicle from prior air temperature measurements, determining a change in temperature value using the air temperature at the vehicle and the at least one air temperature measurement ahead of the vehicle, and using the change in temperature value to-reposition the airflow inlet, to cause the shock wave to maintain substantially the same position within the inlet as the airflow temperature changes within the inlet.

  10. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    SciTech Connect

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue Fang, Jing

    2015-10-15

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  11. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    NASA Astrophysics Data System (ADS)

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui; Zhang, Jue; Fang, Jing

    2015-10-01

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  12. Annual temperature anomaly trends correlate with coral reef trajectory across the Pacific

    NASA Astrophysics Data System (ADS)

    Riegl, B. M.; Wieters, E.; Bruckner, A.; Purkis, S.

    2013-05-01

    The future survival of coral reefs depends on the envelope of critical climatic conditions determining the severity of impacts on the ecosystem. While coral health is strongly determined by extreme heat events, that lead to bleaching and often death, chronic "heat loading" may also disadvantage corals by making them more susceptible to, for example, diseases. On the other hand, it has been shown that coral living in hotter areas have higher bleaching thresholds and may be affected by less mortality at extreme events. This level at which heat anomalies lead to coral mortality varies widely across oceans, from ~31 deg C across the Caribbean to ~32 deg C in the Great Barrier Reef to 37.5 deg C in the Persian/Arabian Gulf. Thus, there clearly exists local adaptation and the extremes required to kill reefs strongly vary among regions. This could be be interpreted as suggesting that as long as bleaching temperatures are not reached, increased overall heat content expressed by a positive annual thermal anomaly, might actually foster coral resilience. Is there evidence for or against such an argument? Bleaching events have been occurring worldwide with variable recurrence and variable subsequent recovery. Despite demonstrated adaptation to higher-than-usual mean summer temperatures, reefs in the Arabian Gulf and the Red Sea are on a declining trajectory. This coincides with consistent warming in the region. Mean annual anomalies of ocean temperature (since 1870) and atmospheric temperatures (since 1950) increase throughout the region. Since 1994 (Red Sea) and 1998 (southern Arabian Gulf) all mean annual anomalies have been positive and this period has coincided with repeated, severe bleaching events. In the Eastern Pacific (Galapagos and Easter Island), the trend of mean annual temperature anomalies has been declining and coral cover has been increasing. Thus, trends in coral cover and mean annual anomaly are negatively correlated in both regions. Despite strong impacts

  13. Estimation of daily mean air temperature from satellite derived radiometric data

    NASA Technical Reports Server (NTRS)

    Phinney, D.

    1976-01-01

    The Screwworm Eradication Data System (SEDS) at JSC utilizes satellite derived estimates of daily mean air temperature (DMAT) to monitor the effect of temperature on screwworm populations. The performance of the SEDS screwworm growth potential predictions depends in large part upon the accuracy of the DMAT estimates.

  14. Air temperature variations on the Atlantic - Arctic boundary since 1802: the low-frequency pattern and ocean teleconnections

    NASA Astrophysics Data System (ADS)

    Wood, K. R.; Overland, J. E.; Jónsson, T.; Smoliak, B. V.

    2010-12-01

    A two-hundred year instrumental record of annual surface air temperature (SAT) in the Atlantic - Arctic boundary region was reconstructed from four station-based composite time series (Fig. 1). Credibility is supported by ice core records, other temperature proxies, and historical evidence. This record (designated TNA) provides new perspective on past climate fluctuations in a region where pivotal climate system processes occur and where unexplained low-frequency variations were observed during the 20th century. TNA shows that the low-frequency pattern of the 20th century does not have a clear analog in the previous century. During the 19th century decadal-scale climate fluctuations occurred in irregular episodes; none were as distinctive as the early 20th century warming event (~1920 to mid-century), which is the most striking historical feature in the record. Evidence of a strong teleconnection between TNA and SST anomalies in the western boundary current - southern recirculation gyre (WBC) region of the North Atlantic Ocean provides an opportunity to reframe the problem of low-frequency variability in the region in terms tractable to theory and empirical investigation. Positive fluctuations in both TNA (and by extension other climate variables associated with it) and SST in the WBC region could be initiated by persistent variations in the large-scale atmospheric circulation that promote the advection of warm maritime air into the Atlantic - Arctic region and simultaneously limit flux-induced cooling in the Nordic Seas and the WBC/recirculation gyre region. This leads to enhanced ocean heat storage in both regions and may consequently reinforce anomalous atmospheric circulation patterns like those observed during the early 20th century warming event. Figure 1. Extended annual mean SAT record for the Atlantic - Arctic boundary region (TNA). The early 20th century warming (ETCW) episode is marked. Regions represented by station-based composite SAT records used in

  15. Prediction of air temperature for thermal comfort of people using sleeping bags: a review

    NASA Astrophysics Data System (ADS)

    Huang, Jianhua

    2008-11-01

    Six models for determining air temperatures for thermal comfort of people using sleeping bags were reviewed. These models were based on distinctive metabolic rates and mean skin temperatures. All model predictions of air temperatures are low when the insulation values of the sleeping bag are high. Nevertheless, prediction variations are greatest for the sleeping bags with high insulation values, and there is a high risk of hypothermia if an inappropriate sleeping bag is chosen for the intended conditions of use. There is, therefore, a pressing need to validate the models by wear trial and determine which one best reflects ordinary consumer needs.

  16. Geothermics of Climate Change: Linking Ground and Air Temperature Change Through Repeat Temperature Measurements in Boreholes From Northwest Utah

    NASA Astrophysics Data System (ADS)

    Davis, M. G.; Harris, R. N.; Chapman, D. S.

    2007-12-01

    Temperature-depth profiles measured in boreholes contain important information about the Earth's changing surface temperature and provide a direct method for reconstructing surface temperature variations over the past several centuries. Differences between temperature-depth logs, on annual to decadal timescales, provide an important test of borehole thermometry. Twelve temperature-depth logs at the northwestern Utah Emigrant Pass Observatory (EPO) borehole, GC-1, seven at borehole SI-1 and five at borehole DM-1, were acquired between the years 1978 and 2007. Differences in temperature logs extend to about 100 m. Below 100 m, differences between temperature logs are effectively zero. SAT data from the meteorological station at EPO and nearby Historical Climatology Network stations are used as a forcing function at the Earth's surface and diffused into the subsurface. These transients reproduce observed subsurface temperature variations reasonably well at each borehole. Comparisons between repeated temperature-depth profiles and diffused SAT transients over the same time period offer strong support for using GST histories to complement SAT data and multi-proxy reconstructions in climate change studies.

  17. Use of Temperature Sensors to Determine Exclusivity of Improved Stove Use and Associated Household Air Pollution Reductions in Kenya.

    PubMed

    Lozier, Matthew J; Sircar, Kanta; Christensen, Bryan; Pillarisetti, Ajay; Pennise, David; Bruce, Nigel; Stanistreet, Debbi; Naeher, Luke; Pilishvili, Tamara; Farrar, Jennifer Loo; Sage, Michael; Nyagol, Ronald; Muoki, Justus; Wofchuck, Todd; Yip, Fuyuen

    2016-04-19

    Household air pollution (HAP) contributes to 3.5-4 million annual deaths globally. Recent interventions using improved cookstoves (ICS) to reduce HAP have incorporated temperature sensors as stove use monitors (SUMs) to assess stove use. We deployed SUMs in an effectiveness study of 6 ICSs in 45 Kenyan rural homes. Stove were installed sequentially for 2 weeks and kitchen air monitoring was conducted for 48 h during each 2-week period. We placed SUMs on the ICSs and traditional cookstoves (TCS), and the continuous temperature data were analyzed using an algorithm to examine the number of cooking events, days of exclusive use of ICS, and how stove use patterns affect HAP. Stacking, defined as using both a TCS and an ICS in the same day, occurred on 40% of the study days, and exclusive use of the ICS occurred on 25% of study days. When researchers were not present, ICS use declined, which can have implications for long-term stove adoption in these communities. Continued use of TCSs was also associated with higher HAP levels. SUMs are a valuable tool for characterizing stove use and provide additional information to interpret HAP levels measured during ICS intervention studies. PMID:26953674

  18. Comparison of signaling interactions determining annual and perennial plant growth in response to low temperature

    PubMed Central

    Wingler, Astrid

    2015-01-01

    Low temperature inhibits plant growth despite the fact that considerable rates of photosynthetic activity can be maintained. Instead of lower rates of photosynthesis, active inhibition of cell division and expansion is primarily responsible for reduced growth. This results in sink limitation and enables plants to accumulate carbohydrates that act as compatible solutes or are stored throughout the winter to enable re-growth in spring. Regulation of growth in response to temperature therefore requires coordination with carbon metabolism, e.g., via the signaling metabolite trehalose-6-phosphate. The phytohormones gibberellin (GA) and jasmonate (JA) play an important role in regulating growth in response to temperature. Growth restriction at low temperature is mainly mediated by DELLA proteins, whose degradation is promoted by GA. For annual plants, it has been shown that the GA/DELLA pathway interacts with JA signaling and C-repeat binding factor dependent cold acclimation, but these interactions have not been explored in detail for perennials. Growth regulation in response to seasonal factors is, however, particularly important in perennials, especially at high latitudes. In autumn, growth cessation in trees is caused by shortening of the daylength in interaction with phytohormone signaling. In perennial grasses seasonal differences in the sensitivity to GA may enable enhanced growth in spring. This review provides an overview of the signaling interactions that determine plant growth at low temperature and highlights gaps in our knowledge, especially concerning the seasonality of signaling responses in perennial plants. PMID:25628637

  19. Influence of Air Temperature and Humidity on Dehydration Equilibria and Kinetics of Theophylline

    PubMed Central

    Touil, Amira; Peczalski, Roman; Timoumi, Souad; Zagrouba, Fethi

    2013-01-01

    The effect of hygrothermal conditions (air temperature and relative humidity) on the dehydration of theophylline monohydrate was investigated. Firstly, the equilibrium states of theophylline were investigated. The data from gravimetric analysis at constant temperature and humidity were reported as desorption isotherms. The PXRD analysis was used to identify the different polymorphic forms of theophylline: the monohydrate, the metastable anhydrate, and the stable anhydrate. Solid-solid phase diagrams for two processing times were proposed. Secondly, the dehydration kinetics were studied. The water content evolutions with time were recorded at several temperatures from 20°C to 80°C and several relative humidities from 4% to 50%. Different mathematical models were used to fit the experimental data. The spatially averaged solution of 2D Fickian transient diffusion equation best represented the water mass loss versus time experimental relationship. The dehydration rate constant was found to increase exponentially with air temperature and to decrease exponentially with air relative humidity. PMID:26556000

  20. Influence of Air Temperature and Humidity on Dehydration Equilibria and Kinetics of Theophylline.

    PubMed

    Touil, Amira; Peczalski, Roman; Timoumi, Souad; Zagrouba, Fethi

    2013-01-01

    The effect of hygrothermal conditions (air temperature and relative humidity) on the dehydration of theophylline monohydrate was investigated. Firstly, the equilibrium states of theophylline were investigated. The data from gravimetric analysis at constant temperature and humidity were reported as desorption isotherms. The PXRD analysis was used to identify the different polymorphic forms of theophylline: the monohydrate, the metastable anhydrate, and the stable anhydrate. Solid-solid phase diagrams for two processing times were proposed. Secondly, the dehydration kinetics were studied. The water content evolutions with time were recorded at several temperatures from 20°C to 80°C and several relative humidities from 4% to 50%. Different mathematical models were used to fit the experimental data. The spatially averaged solution of 2D Fickian transient diffusion equation best represented the water mass loss versus time experimental relationship. The dehydration rate constant was found to increase exponentially with air temperature and to decrease exponentially with air relative humidity. PMID:26556000

  1. The temperature fields measurement of air in the car cabin by infrared camera

    NASA Astrophysics Data System (ADS)

    Pešek, M.

    2013-04-01

    The article deals with the temperature fields measurement of air using the Jenoptic Variocam infrared camera inside the car Škoda Octavia Combi II. The temperature fields with the use of auxiliary material with a high emissivity value were visualized. The measurements through the viewing window with a high transmissivity value were performed. The viewing windows on the side car door were placed. In the rear car area, the temperature fields of air on the spacious sheet of auxiliary material were visualized which is a suitable method for 2D airstreams. In the front car area, the temperature fields in the air were measured with the use of the measuring net which is suitable for 3D airstreams measuring.

  2. Variation in photosynthetic response to temperature in a guild of winter annual plants.

    PubMed

    Gremer, Jennifer R; Kimball, Sarah; Angert, Amy L; Venable, D Lawrence; Huxman, Travis E

    2012-12-01

    How species respond to environmental variation can have important consequences for population and community dynamics. Temperature, in particular, is one source of variation expected to strongly influence plant performance. Here, we compared photosynthetic responses to temperature across a guild of winter annual plants. Previous work in this system identified a trade-off between relative growth rate (RGR) and water-use efficiency (WUE) that predicts species differences in population dynamics over time, which then contribute to long-term species coexistence. Interestingly, species with high WUE invest in photosynthetic processes that appear to maximize carbon assimilation, while high-RGR species appear to maximize carbon gain by increasing leaf area for photosynthesis. In high-WUE species, higher rates of carbon acquisition were associated with increased investment into light-driven electron transport (J(max)). We tested whether such allocation allows these plants to have greater photosynthetic performance at lower temperatures by comparing the temperature sensitivity of photosynthesis across species in the community. Six species were grown in buried pots in the field, allowing them to experience natural changes in seasonal temperature. Plants were taken from the field and placed in growth chambers where photosynthetic performance was measured following short-term exposure to a wide range of temperatures. These measurements were repeated throughout the season. Our results suggest that high-WUE species are more efficient at processing incoming light, as measured by chlorophyll fluorescence, and exhibit higher net photosynthetic rates (A(net)) than high-RGR species, and these advantages are greatest at low temperatures. Sampling date differentially affected fluorescence across species, while species had similar seasonal changes in A(net). Our results suggest that species-specific responses to temperature contribute to the WUE-RGR trade-off that has been shown to

  3. The upper explosion limit of lower alkanes and alkenes in air at elevated pressures and temperatures.

    PubMed

    Van den Schoor, F; Verplaetsen, F

    2006-01-16

    The upper explosion limit (UEL) of ethane-air, propane-air, n-butane-air, ethylene-air and propylene-air mixtures is determined experimentally at initial pressures up to 30 bar and temperatures up to 250 degrees C. The experiments are performed in a closed spherical vessel with an internal diameter of 200 mm. The mixtures are ignited by fusing a coiled tungsten wire, placed at the centre of the vessel, by electric current. Flame propagation is said to have taken place if there is a pressure rise of at least 1% of the initial pressure after ignition of the mixture. In the pressure-temperature range investigated, a linear dependence of UEL on temperature and a bilinear dependence on pressure are found except in the vicinity of the auto-ignition range. A comparison of the UEL data of the lower alkanes shows that the UEL expressed as equivalence ratio (the actual fuel/air ratio divided by the stoichiometric fuel/air ratio) increases with increasing carbon number in the homologous series of alkanes. PMID:16154265

  4. Data Assimilation Experiments using Quality Controlled AIRS Version 5 Temperature Soundings

    NASA Technical Reports Server (NTRS)

    SUsskind, Joel

    2008-01-01

    The AIRS Science Team Version 5 retrieval algorithm has been finalized and is now operational at the Goddard DAAC in the processing (and reprocessing) of all AIRS data. The AIRS Science Team Version 5 retrieval algorithm contains two significant improvements over Version 4: 1) Improved physics allows for use of AIRS observations in the entire 4.3 pm C02 absorption band in the retrieval of temperature profile T(p) during both day and night. Tropospheric sounding 15 pm C02 observations are now used primarily in the generation of cloud cleared radiances Ri. This approach allows for the generation of accurate values of Ri and T(p) under most cloud conditions. 2) Another very significant improvement in Version 5 is the ability to generate accurate case-by-case, level-by-level error estimates for the atmospheric temperature profile, as well as for channel-by- channel error estimates for Ri. These error estimates are used for quality control of the retrieved products. We have conducted forecast impact experiments assimilating AIRS temperature profiles with different levels of quality control using the NASA GEOS-5 data assimilation system. Assimilation of quality controlled T(p) resulted in significantly improved forecast skill compared to that obtained from analyses obtained when all data used operationally by NCEP, except for AIRS data, is assimilated. We also conducted an experiment assimilating AIRS radiances uncontaminated by clouds, as done Operationally by ECMWF and NCEP. Forecasts resulting from assimilated AIRS radiances were of poorer quality than those obtained assimilating AIRS temperatures.

  5. Improving Forecast Skill by Assimilation of Quality Controlled AIRS Version 5 Temperature Soundings

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Reale, Oreste

    2009-01-01

    The AIRS Science Team Version 5 retrieval algorithm has been finalized and is now operational at the Goddard DAAC in the processing (and reprocessing) of all AIRS data. The AIRS Science Team Version 5 retrieval algorithm contains two significant improvements over Version 4: 1) Improved physics allows for use of AIRS observations in the entire 4.3 micron CO2 absorption band in the retrieval of temperature profile T(p) during both day and night. Tropospheric sounding 15 micron CO2 observations are now used primarily in the generation of cloud cleared radiances R(sub i). This approach allows for the generation of accurate values of R(sub i) and T(p) under most cloud conditions. 2) Another very significant improvement in Version 5 is the ability to generate accurate case-by-case, level-by-level error estimates for the atmospheric temperature profile, as well as for channel-by-channel error estimates for R(sub i). These error estimates are used for Quality Control of the retrieved products. We have conducted forecast impact experiments assimilating AIRS temperature profiles with different levels of Quality Control using the NASA GEOS-5 data assimilation system. Assimilation of Quality Controlled T(p) resulted in significantly improved forecast skill compared to that obtained from analyses obtained when all data used operationally by NCEP, except for AIRS data, is assimilated. We also conducted an experiment assimilating AIRS radiances uncontaminated by clouds, as done operationally by ECMWF and NCEP. Forecast resulting from assimilated AIRS radiances were of poorer quality than those obtained assimilating AIRS temperatures.

  6. Air Ingress Accident in a High Temperature Reactor with Prismatic Fuel

    SciTech Connect

    Haque, H.; Brinkmann, G.

    2006-07-01

    In this paper, the safety behavior of the new generation high temperature reactors (HTRs) with prismatic fuels during air ingress accident conditions has been investigated. These reactors conceived primarily for the production of hydrogen, are characterized by their inherent safety features with respect to passive decay heat removal through conduction, radiation and natural convection. Air ingress is an HTR specific event. The potential threat posed by air ingress lies in the chemical reaction of oxygen with hot graphite at a temperature above 500 deg. C leading to reaction heat and graphite corrosion. A substantial amount of graphite burn-off can take place only if sufficient amount of air enters into the core. In order to better assess the phenomena of air ingress into the reactor, it is postulated that breaks are present above and below the reactor core and that unobstructed ingress of air through them is possible. It is obvious that the air ingress incident has to be preceded by a depressurization accident. For this hypothetical scenario the maximum possible air flow rate through the core resulting solely from the pressure losses in the core is determined as a function of the break cross sections exposed above and below the core. This paper demonstrates the thermal behavior of the ANTARES reactor (operating inlet/outlet temperatures 450/850 deg. C) for various air flow rates with respect to graphite burn-off and maximum temperatures of fuel and bottom reflector region. It indicates the limiting time at which the graphite layer of fuel will be completely burnt-off and the pellets exposed. (authors)

  7. Evaluation of the Global Land Data Assimilation System (GLDAS) air temperature data products

    NASA Astrophysics Data System (ADS)

    Ji, L.; Senay, G. B.; Verdin, J. P.

    2014-12-01

    There is a high demand for agro-hydrologic models to use gridded surface air temperature data as the model input for estimating regional and global water budget and cycle. The Global Land Data Assimilation System (GLDAS) developed by combining simulation models with observations provides a long-term gridded meteorological dataset at the global coverage. However, the GLDAS air temperature products have not been comprehensively evaluated, although the accuracy of the products was assessed in limited areas. In this study, we compared the daily 0.25° resolution GLDAS air temperature data with two reference datasets: (1) 1-km resolution gridded Daymet data (2002 and 2010) for the Conterminous United States, and (2) global meteorological observations (2000 - 2011) archived from the Global Historical Climatology Network (GHCN). The comparison of the GLDAS datasets with the GHCN datasets including 13,511 weather stations indicates a fairly high accuracy of the GLDAS data for daily maximum temperature [bias is 1.2 C°, root mean square error (RMSE) is 3.9 C°, and R2 is 0.92] and daily minimum temperature (bias is -1.4 C°, RMSE is 5.4 C°, and R2 is 0.82). The quality of the GLDAS air temperature data, however, is not always consistent in different regions of the world; for example, some areas in Africa and South America show relatively low accurate estimates. Spatial and temporal analyses reveal a high agreement between GLDAS and Daymet daily air temperature datasets, although spatial details in high mountainous areas are not sufficiently estimated by the GLDAS data. Our evaluation of the GLDAS data demonstrates that the air temperature estimates are generally accurate, but cautions should be taken when the data are used in mountainous areas or places with sparse weather stations.

  8. Fault diagnosis and temperature sensor recovery for an air-handling unit

    SciTech Connect

    Lee, W.Y.; Shin, D.R.; House, J.M.

    1997-12-31

    The presence of faults and the influence they have on system operation is a real concern in the heating, ventilating, and air-conditioning (HVAC) community. A fault can be defined as an inadmissible or unacceptable property of a system or a component. Unless corrected, faults can lead to increased energy use, shorter equipment life, and uncomfortable and/or unhealthy conditions for building occupants. This paper describes the use of a two-stage artificial neural network for fault diagnosis in a simulated air-handling unit. The stage one neural network is trained to identify the subsystem in which a fault occurs. The stage two neural network is trained to diagnose the specific cause of a fault at the subsystem level. Regression equations for the supply and mixed-air temperatures are obtained from simulation data and are used to compute input parameters to the neutral networks. Simulation results are presented that demonstrate that, after a successful diagnosis of a supply air temperature sensor fault, the recovered estimate of the supply air temperature obtained from the regression equation can be used in a feedback control loop to bring the supply air temperature back to the setpoint value. Results are also presented that illustrate the evolution of the diagnosis of the two-stage artificial neural network from normal operation to various fault modes of operation.

  9. An ultrasonic air temperature measurement system with self-correction function for humidity

    NASA Astrophysics Data System (ADS)

    Tsai, Wen-Yuan; Chen, Hsin-Chieh; Liao, Teh-Lu

    2005-02-01

    This paper proposes an ultrasonic measurement system for air temperature with high accuracy and instant response. It can measure the average temperature of the environmental air by detecting the changes of the speed of the ultrasound in the air. The changes of speed of sound are computed from combining variations of time-of-flight (TOF) from a binary frequency shift-keyed (BFSK) ultrasonic signal and phase shift from continuous waves [11]. In addition, another proposed technique for the ultrasonic air temperature measurement is the self-correction functionality within a highly humid environment. It utilizes a relative humidity/water vapour sensor and applies the theory of how sound speed changes in a humid environment. The proposed new ultrasonic air temperature measurement has the capability of self-correction for the environment variable of humidity. Especially under the operational environment with high fluctuations of various humidity levels, the proposed system can accurately self-correct the errors on the conventional ultrasonic thermometer caused by the changing density of the vapours in the air. Including the high humidity effect, a proof-of-concept experiment demonstrates that in dry air (relative humidity, RH = 10%) without humidity correction, it is accurate to ±0.4 °C from 0 °C to 80 °C, while in highly humid air (relative humidity, RH = 90%) with self-correction functionality, it is accurate to ±0.3 °C from 0 °C to 80 °C with 0.05% resolution and temperature changes are instantly reflected within 100 ms.

  10. The effect of air temperature and human thermal indices on mortality in Athens, Greece

    NASA Astrophysics Data System (ADS)

    Nastos, Panagiotis T.; Matzarakis, Andreas

    2012-05-01

    This paper investigates whether there is any association between the daily mortality for the wider region of Athens, Greece and the thermal conditions, for the 10-year period 1992-2001. The daily mortality datasets were acquired from the Hellenic Statistical Service and the daily meteorological datasets, concerning daily maximum and minimum air temperature, from the Hellinikon/Athens meteorological station, established at the headquarters of the Greek Meteorological Service. Besides, the daily values of the thermal indices Physiologically Equivalent Temperature (PET) and Universal Thermal Climate Index (UTCI) were evaluated in order to interpret the grade of physiological stress. The first step was the application of Pearson's χ 2 test to the compiled contingency tables, resulting in that the probability of independence is zero ( p = 0.000); namely, mortality is in close relation to the air temperature and PET/UTCI. Furthermore, the findings extracted by the generalized linear models showed that, statistically significant relationships ( p < 0.01) between air temperature, PET, UTCI and mortality exist on the same day. More concretely, on one hand during the cold period (October-March), a 10°C decrease in daily maximum air temperature, minimum air temperature, temperature range, PET and UTCI is related with an increase 13%, 15%, 2%, 7% and 6% of the probability having a death, respectively. On the other hand, during the warm period (April-September), a 10°C increase in daily maximum air temperature, minimum air temperature, temperature range, PET and UTCI is related with an increase 3%, 1%, 10%, 3% and 5% of the probability having a death, respectively. Taking into consideration the time lag effect of the examined parameters on mortality, it was found that significant effects of 3-day lag during the cold period appears against 1-day lag during the warm period. In spite of the general aspect that cold conditions seem to be favourable factors for daily mortality

  11. Quantifying energy and mass transfer in crop canopies: sensors for measurement of temperature and air velocity

    NASA Technical Reports Server (NTRS)

    Bugbee, B.; Monje, O.; Tanner, B.

    1996-01-01

    Here we report on the in situ performance of inexpensive, miniature sensors that have increased our ability to measure mass and energy fluxes from plant canopies in controlled environments: 1. Surface temperature. Canopy temperature measurements indicate changes in stomatal aperture and thus latent and sensible heat fluxes. Infrared transducers from two manufacturers (Exergen Corporation, Newton, MA; and Everest Interscience, Tucson, AZ, USA) have recently become available. Transducer accuracy matched that of a more expensive hand-held infrared thermometer. 2. Air velocity varies above and within plant canopies and is an important component in mass and energy transfer models. We tested commercially-available needle, heat-transfer anemometers (1 x 50 mm cylinder) that consist of a fine-wire thermocouple and a heater inside a hypodermic needle. The needle is heated and wind speed determined from the temperature rise above ambient. These sensors are particularly useful in measuring the low wind speeds found within plant canopies. 3. Accurate measurements of air temperature adjacent to plant leaves facilitates transport phenomena modeling. We quantified the effect of radiation and air velocity on temperature rise in thermocouples from 10 to 500 micrometers. At high radiation loads and low wind speeds, temperature errors were as large as 7 degrees C above air temperature.

  12. Ambient air pollution, temperature and out-of-hospital coronary deaths in Shanghai, China.

    PubMed

    Dai, Jinping; Chen, Renjie; Meng, Xia; Yang, Changyuan; Zhao, Zhuohui; Kan, Haidong

    2015-08-01

    Few studies have evaluated the effects of ambient air pollution and temperature in triggering out-of-hospital coronary deaths (OHCDs) in China. We evaluated the associations of air pollution and temperature with daily OHCDs in Shanghai, China from 2006 to 2011. We applied an over-dispersed generalized additive model and a distributed lag nonlinear model to analyze the effects of air pollution and temperature, respectively. A 10 μg/m(3) increase in the present-day PM10, PM2.5, SO2, NO2 and CO were associated with increases in OHCD mortality of 0.49%, 0.68%, 0.88%, 1.60% and 0.08%, respectively. A 1 °C decrease below the minimum-mortality temperature corresponded to a 3.81% increase in OHCD mortality on lags days 0-21, and a 1 °C increase above minimum-mortality temperature corresponded to a 4.61% increase over lag days 0-3. No effects were found for in-hospital coronary deaths. This analysis suggests that air pollution, low temperature and high temperature may increase the risk of OHCDs. PMID:25875162

  13. Effect of green roofs on air temperature; measurement study of well-watered and dry conditions

    NASA Astrophysics Data System (ADS)

    Solcerova, Anna; van de Ven, Frans; Wang, Mengyu; van de Giesen, Nick

    2016-04-01

    Rapid urbanization and increasing number and duration of heat waves poses a need for understanding urban climate and ways to mitigate extremely high temperatures. One of repeatedly suggested and often investigated methods to moderate the so called urban heat island are green roofs. This study investigates several extensive green roofs in Utrecht (NL) and their effect on air temperature right above the roof surface. Air temperature was measured 15 and 30 cm above the roof surface and also in the substrate. We show that under normal condition is air above green roof, compared to white gravel roof, colder at night and warmer during day. This suggest that green roofs might help decrease air temperatures at night, when the urban heat island is strongest, but possibly contribute to high temperatures during daytime. We also measured situation when the green roofs wilted and dried out. Under such conditions green roof exhibits more similar behavior to conventional white gravel roof. Interestingly, pattern of soil temperature remains almost the same for both dry and well-prospering green roof, colder during day and warmer at night. As such, green roof works as a buffer of diurnal temperature changes.

  14. Assimilation of Quality Controlled AIRS Temperature Profiles using the NCEP GFS

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Reale, Oreste; Iredell, Lena; Rosenberg, Robert

    2013-01-01

    We have previously conducted a number of data assimilation experiments using AIRS Version-5 quality controlled temperature profiles as a step toward finding an optimum balance of spatial coverage and sounding accuracy with regard to improving forecast skill. The data assimilation and forecast system we used was the Goddard Earth Observing System Model , Version-5 (GEOS-5) Data Assimilation System (DAS), which represents a combination of the NASA GEOS-5 forecast model with the National Centers for Environmental Prediction (NCEP) operational Grid Point Statistical Interpolation (GSI) global analysis scheme. All analyses and forecasts were run at a 0.5deg x 0.625deg spatial resolution. Data assimilation experiments were conducted in four different seasons, each in a different year. Three different sets of data assimilation experiments were run during each time period: Control; AIRS T(p); and AIRS Radiance. In the "Control" analysis, all the data used operationally by NCEP was assimilated, but no AIRS data was assimilated. Radiances from the Aqua AMSU-A instrument were also assimilated operationally by NCEP and are included in the "Control". The AIRS Radiance assimilation adds AIRS observed radiance observations for a select set of channels to the data set being assimilated, as done operationally by NCEP. In the AIRS T(p) assimilation, all information used in the Control was assimilated as well as Quality Controlled AIRS Version-5 temperature profiles, i.e., AIRS T(p) information was substituted for AIRS radiance information. The AIRS Version-5 temperature profiles were presented to the GSI analysis as rawinsonde profiles, assimilated down to a case-by-case appropriate pressure level p(sub best) determined using the Quality Control procedure. Version-5 also determines case-by-case, level-by-level error estimates of the temperature profiles, which were used as the uncertainty of each temperature measurement. These experiments using GEOS-5 have shown that forecasts

  15. A quantitative assessment of the relationship between precipitation deficits and air temperature variations

    NASA Astrophysics Data System (ADS)

    He, B.; Wang, H. L.; Wang, Q. F.; Di, Z. H.

    2015-06-01

    Previous studies have reported precipitation deficits related to temperature extremes. However, how and to what extent precipitation deficits affect surface air temperatures is still poorly understood. In this study, the relationship between precipitation deficits and surface temperatures was examined in China from 1960 to 2012 based on monthly temperature and precipitation records from 565 stations. Significant negative correlations were identified in each season, with the strongest relationships in the summer, indicating that higher temperatures usually accompanied water-deficient conditions and lower temperatures usually accompanied wet conditions. The examination of the correlations based on 30 year moving windows suggested that the interaction between the two variables has declined over the past three decades. Further investigation indicated a higher impact of extreme dry conditions on temperature than that of extreme wet conditions. In addition, a new simple index (Dry Temperature Index, DTI) was developed and used to quantitatively describe the relationship between water deficits and air temperature variations. We tested and compared the DTI in the coldest month (January) and the hottest month (July) of the year, station by station. In both months, the number of stations with a DThighI ≥ 50% was greater than those with a DThighI < 50%, indicating that a greater proportion of higher temperatures occurred during dry conditions. Based on the results, we conclude that water deficits in China are usually correlated to high temperatures but not to low temperatures.

  16. Measuring centimeter-resolution air temperature profiles above land and water using fiber-optic Distributed Temperature Sensing

    NASA Astrophysics Data System (ADS)

    Sigmund, Armin; Pfister, Lena; Olesch, Johannes; Thomas, Christoph K.

    2016-04-01

    The precise determination of near-surface air temperature profiles is of special importance for the characterization of airflows (e.g. cold air) and the quantification of sensible heat fluxes according to the flux-gradient similarity approach. In contrast to conventional multi-sensor techniques, measuring temperature profiles using fiber-optic Distributed Temperature Sensing (DTS) provides thousands of measurements referenced to a single calibration standard at much reduced costs. The aim of this work was to enhance the vertical resolution of Raman scatter DTS measurements up to the centimeter-scale using a novel approach for atmospheric applications: the optical fiber was helically coiled around a meshed fabric. In addition to testing the new fiber geometry, we quantified the measurement uncertainty and demonstrated the benefits of the enhanced-resolution profiles. The fiber-optic cable was coiled around a hollow column consisting of white reinforcing fabric supported by plexiglass rings every meter. Data from two columns of this type were collected for 47 days to measure air temperature vertically over 3.0 and 5.1 m over a gently inclined meadow and over and in a small lake, respectively. Both profiles had a vertical resolution of 1 cm in the lower section near the surface and 5 cm in the upper section with an along-fiber instrument-specific averaging of 1.0 m and a temporal resolution of 30 s. Measurement uncertainties, especially from conduction between reinforcing fabric and fiber-optic cable, were estimated by modeling the fiber temperature via a detailed energy balance approach. Air temperature, wind velocity and radiation components were needed as input data and measured separately. The temperature profiles revealed valuable details, especially in the lowest 1 m above surface. This was best demonstrated for nighttime observations when artefacts due to solar heating did not occur. For example, the dynamics of a cold air layer was detected in a clear night

  17. Performance of High Temperature Air Combustion Boiler with Low NOx Emission

    NASA Astrophysics Data System (ADS)

    Kobayashi, Hiromichi; Ito, Yoshihito; Tsuruta, Naoki; Yoshikawa, Kunio

    Thermal performance in the experiments and three-dimensional numerical simulations for a high temperature air combustion boiler where fuel can be efficiently combusted by high temperature preheated air (800°C-1000°C) is examined. The boiler can burn not only natural gas but also low calorific gas (e. g. full gasification gas obtained from coal or wastes). In the boiler, four regenerative burners are installed. This boiler has new features that not only air but also gasification gas is heated up to 900°C, and combination of burners is switched every 15 seconds where two burners are used as inlets of fuel and air and the other two burners are used as outlets of exhaust gas. Natural gas and syngas obtained from coal are burned. The NOx emission for each fuel is less than 50ppm. The heat transfer of three-dimensional calculation is predicted higher than that of experiment.

  18. Numerical analysis of air-flow and temperature field in a passenger car compartment

    NASA Astrophysics Data System (ADS)

    Kamar, Haslinda Mohamed; Kamsah, Nazri; Mohammad Nor, Ahmad Miski

    2012-06-01

    This paper presents a numerical study on the temperature field inside a passenger's compartment of a Proton Wira saloon car using computational fluid dynamics (CFD) method. The main goal is to investigate the effects of different glazing types applied onto the front and rear windscreens of the car on the distribution of air-temperature inside the passenger compartment in the steady-state conditions. The air-flow condition in the passenger's compartment is also investigated. Fluent CFD software was used to develop a three-dimensional symmetrical model of the passenger's compartment. Simplified representations of the driver and one rear passenger were incorporated into the CFD model of the passenger's compartment. Two types of glazing were considered namely clear insulated laminated tint (CIL) with a shading coefficient of 0.78 and green insulated laminate tint (GIL) with a shading coefficient of 0.5. Results of the CFD analysis were compared with those obtained when the windscreens are made up of clear glass having a shading coefficient of 0.86. Results of the CFD analysis show that for a given glazing material, the temperature of the air around the driver is slightly lower than the air around the rear passenger. Also, the use of GIL glazing material on both the front and rear windscreens significantly reduces the air temperature inside the passenger's compartment of the car. This contributes to a better thermal comfort condition to the occupants. Swirling air flow condition occurs in the passenger compartment. The air-flow intensity and velocity are higher along the side wall of the passenger's compartment compared to that along the middle section of the compartment. It was also found that the use of glazing materials on both the front and rear windscreen has no significant effects on the air-flow condition inside the passenger's compartment of the car.

  19. Characterization of AIRS temperature and water vapor measurement capability using correlative observations

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Eldering, Annmarie; Lee, Sung-Yung

    2005-01-01

    In this presentation we address several fundamental issues in the measurement of temperature and water vapor by AIRS: accuracy, precision, vertical resolution and biases as a function of cloud amount. We use two correlative data sources. First we compare AIRS total water vapor with that from the Advanced microwave Sounding Radiometer for EOS (AMSR-E) instrument, also onboard the Aqua spacecraft. AMSRE uses a mature methodology with a heritage including the operational Special Sensor Microwave Imager (SSM/I) instruments. AIRS and AMSR-E observations are collocated and simultaneous, providing a very large data set for comparison: about 200,000 over-ocean matches daily. We show small cloud-dependent biases between AIRS and AMSR-E total water vapor for several oceanic regions. Our second correlative data source is several hundred dedicated radiosondes launched during AIRS overpasses.

  20. Near Decade Long Tropospheric Air Temperature and Specific Humidity Records from AIRS for CMIP5 Model Evaluation

    NASA Astrophysics Data System (ADS)

    Tian, B.; Fetzer, E.; Kahn, B. H.; Teixeira, J.; Manning, E.; Hearty, T. J.

    2012-12-01

    The peer-reviewed analyses of multi-model outputs from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) experiments will be the most important basis for the next Intergovernmental Panel on Climate Change (IPCC) Assessment Report (AR5). To increase the fidelity of the IPCC AR5, an Obs4MIPs project has been initiated to collect some well-established and well-documented datasets, to organize them according to the CMIP5 model output requirements, and makes them available to the science community for CMIP5 model evaluation. The NASA Atmospheric Infrared Sounder (AIRS) project has produced monthly mean tropospheric air temperature (ta, K) and specific humidity (hus, kg/kg) products as part of the Obs4MIPS project. In this paper, we first describe these two AIRS datasets in terms of data description, origin, validation and caveats for model-observation comparison. We then document the climatological mean features of these two AIRS datasets and compare them to those from NASA's Modern Era Retrospective analysis for Research and Applications (MERRA) for AIRS data validation and CMIP5 model simulations for CMIP5 model evaluation. As expected, the 9-year AIRS data show several well-known climatological features of tropospheric ta and hus, such as the strong meridional and vertical gradients of tropospheric ta and hus and strong zonal gradient of tropospheric hus. AIRS data also show the strong connections between the tropospheric hus, atmospheric circulation and deep convection. In comparison to MERRA, AIRS seems to be colder in the free troposphere but warmer in the boundary layer with differences typically less than 1 K. AIRS is wetter (~10%) in the tropical boundary layer but drier (around 30%) in the tropical free troposphere and the extratropical troposphere. In particular, the large AIRS-MERRA hus differences are mainly located in the cloudy regions, such as the Intertropical Convergence Zone (ITCZ), the South Pacific Convergence Zone (SPCZ) and the

  1. Short-term effects of air temperature on mortality and effect modification by air pollution in three cities of Bavaria, Germany: A time-series analysis

    EPA Science Inventory

    Background: Air temperature has been shown to be associated with mortality; however, only very few studies have been conducted in Germany. This study examined the association between daily air temperature and cause-specific mortality in Bavaria, Southern Germany. Moreover, we inv...

  2. The comparative performance of an aviation engine at normal and high inlet air temperatures

    NASA Technical Reports Server (NTRS)

    Gardiner, Arthur W; Schey, Oscar W

    1928-01-01

    This report presents some results obtained during an investigation to determine the effect of high inlet air temperature on the performance of a Liberty 12 aviation engine. The purpose of this investigation was to ascertain, for normal service carburetor adjustments and a fixed ignition advance, the relation between power and temperature for the range of carburetor air temperatures that may be encountered when supercharging to sea level pressure at altitudes of over 20,000 feet and without intercooling when using plain aviation gasoline and mixtures of benzol and gasoline. The results show that for the conditions of test, both the brake and indicated power decrease with increase in air temperature at a faster rate than given by the theoretical assumption that power varies inversely as the square root of the absolute temperature. On a brake basis, the order of the difference in power for a temperature difference of 120 degrees F. Is 3 to 5 per cent. The observed relation between power and temperature when using the 30-70 blend was found to be linear. But, although these differences are noted, the above theoretical assumption may be considered as generally applicable except where greater precision over a wide range of temperatures is desired, in which case it appears necessary to test the particular engine under the given conditions. (author)

  3. Flow and containment characteristics of an air-curtain fume hood operated at high temperatures.

    PubMed

    Chen, Jia-Kun; Huang, Rong Fung; Hsin, Pei-Yi; Hsu, Ching Min; Chen, Chun-Wann

    2012-01-01

    The flow and leakage characteristics of the air-curtain fume hood under high temperature operation (between 100°C and 250°C) were studied. Laser-assisted flow visualization technique was used to reveal the hot plume movements in the cabinet and the critical conditions for the hood-top leakage. The sulfur hexafluoride tracer-gas concentration test method was employed to examine the containment spillages from the sash opening and the hood top. It was found that the primary parameters dominating the behavior of the flow field and hood performance are the sash height and the suction velocity as an air-curtain hood is operated at high temperatures. At large sash height and low suction velocity, the air curtain broke down and accompanied with three-dimensional flow in the cabinet. Since the suction velocity was low and the sash opening was large, the makeup air drawn down from the hood top became insufficient to counter act the rising hot plume. Under this situation, containment leakage from the sash opening and the hood top was observed. At small sash opening and high suction velocity, the air curtain presented robust characteristics and the makeup air flow from the hood top was sufficiently large. Therefore the containment leakages from the sash opening and the hood top were not observed. According to the results of experiments, quantitative operation sash height and suction velocity corresponding to the operation temperatures were suggested. PMID:22293724

  4. Torrefaction and low temperature carbonization of oil palm fiber and Eucalyptus in nitrogen and air atmospheres.

    PubMed

    Lu, Ke-Miao; Lee, Wen-Jhy; Chen, Wei-Hsin; Liu, Shih-Hsien; Lin, Ta-Chang

    2012-11-01

    Torrefaction is a pretreatment method for upgrading biomass as solid fuels. To provide flexible operations for effectively upgrading biomass at lower costs, the aim of this study was to investigate the properties of oil palm fiber and eucalyptus pretreated in nitrogen and air atmospheres at temperatures of 250-350°C for 1h. Based on energy and solid yield and introducing an energy-mass co-benefit index (EMCI), oil palm fiber pretreatment under nitrogen at 300°C provided the solid fuel with higher energy density and less volume compared to other temperatures. Pretreatment of oil palm fiber in air resulted in the fuel with low solid and energy yields and is therefore not recommended. For eucalyptus, nitrogen and air can be employed to upgrade the biomass, and the suggested temperatures are 325 and 275°C, respectively. PMID:22940305

  5. An experimental study on high temperature and low oxygen air combustion

    NASA Astrophysics Data System (ADS)

    Kim, W. B.; Chung, D. H.; Yang, J. B.; Noh, D. S.

    2000-06-01

    High temperature preheated and diluted air combustion has been confirmed as the technology, mainly applied to industrial furnaces and kilns, to realize higher thermal efficiency and lower emissions. The purpose of this study was to investigate fundamental aspects of the above-mentioned combustion experimentally and to compare with those in ordinary hydrocarbon combustion with room temperature air. The test items were exhaust gas components of CO, NOx, flame shape and radical components of CH, OH and C2, which were measured with gas analyser, camera and ICCD(Intensified Charged - Coupled Device) camera. Many phenomena as results appeared in combustion with the oxidizer, low oxygen concentration and extremely high temperature air, such as expansion of the flammable limits, increased flame propagation speed, it looked so strange as compared with those in existing combustion technology. We confirmed that such extraordinary phenomena were believable through the hot-test experiment.

  6. The effect of air temperature on the sappan wood extract drying

    NASA Astrophysics Data System (ADS)

    Djaeni, M.; Triyastuti, M. S.; Asiah, N.; Annisa, A. N.; Novita, D. A.

    2015-12-01

    The sappan wood extract contain natural colour called brazilin that can be used as a food colouring and antioxidant. The product is commonly found as a dry extract powder for consummer convenience. The spray dryer with air dehumidification can be an option to retain the colour and antioxidant agent. This paper discusses the effect of air temperature on sappan wood extract drying that was mixed with maltodextrin. As responses, the particle size, final moisture content, and extract solubility degradation were observed. In all cases, the process conducted in temperature ranging 90 - 110°C can retain the brazilin quality as seen in solubility and particle size. In addition, the sappan wood extract can be fully dried with moisture content below 2%. Moreover, with the increase of air temperature, the particle size of dry extract can be smaller.

  7. The influence of snow depth and surface air temperature on satellite-derived microwave brightness temperature. [central Russian steppes, and high plains of Montana, North Dakota, and Canada

    NASA Technical Reports Server (NTRS)

    Foster, J. L.; Hall, D. K.; Chang, A. T. C.; Rango, A.; Allison, L. J.; Diesen, B. C., III

    1980-01-01

    Areas of the steppes of central Russia, the high plains of Montana and North Dakota, and the high plains of Canada were studied in an effort to determine the relationship between passive microwave satellite brightness temperature, surface air temperature, and snow depth. Significant regression relationships were developed in each of these homogeneous areas. Results show that sq R values obtained for air temperature versus snow depth and the ratio of microwave brightness temperature and air temperature versus snow depth were not as the sq R values obtained by simply plotting microwave brightness temperature versus snow depth. Multiple regression analysis provided only marginal improvement over the results obtained by using simple linear regression.

  8. Estimation Accuracy of air Temperature and Water Vapor Amount Above Vegetation Canopy Using MODIS Satellite Data

    NASA Astrophysics Data System (ADS)

    Tomosada, M.

    2005-12-01

    Estimation accuracy of the air temperature and water vapor amount above vegetation canopy using MODIS satellite data is indicated at AGU fall meeting. The air temperature and water vapor amount which are satisfied the multilayer energy budget model from the ground surface to the atmosphere are estimated. Energy budget models are described the fluxes of sensible heat and latent heat exchange for the ground surface and the vegetated surface. Used MODIS satellite data is the vegetated surface albedo which is calculated from visible and near infrared band data, the vegetated surface temperature, NDVI (Normalized Difference Vegetation Index), LAI (Leaf Area Index). Estimation accuracy of air temperature and water vapor amount above vegetation canopy is evaluated comparing with the value which is measured on a flux research tower in Tomakomai northern forest of Japan. Meteorological parameters such as temperature, wind speed, water vapor amount, global solar radiation are measured on a flux tower from the ground to atmosphere. Well, MODIS satellite observes at day and night, and it snows in Tomakomai in winter. Therefore, estimation accuracy is evaluated dividing on at daytime, night, snowfall day, and not snowfall day. There is the investigation of the undeveloped region such as dense forest and sea in one of feature of satellite observation. Since there is almost no meteorological observatory at the undeveloped region so far, it is hard to get the meteorological parameters. Besides, it is the one of the subject of satellite observation to get the amount of physical parameter. Although the amount of physical parameter such as surface temperature and concentration of chlorophyll-a are estimated by satellite, air temperature and amount of water vapor above vegetation canopy have not been estimated by satellite. Therefore, the estimation of air temperature and water vapor amount above vegetation canopy using satellite data is significant. Further, a highly accurate

  9. Thermodynamic and Transport Properties of Real Air Plasma in Wide Range of Temperature and Pressure

    NASA Astrophysics Data System (ADS)

    Wang, Chunlin; Wu, Yi; Chen, Zhexin; Yang, Fei; Feng, Ying; Rong, Mingzhe; Zhang, Hantian

    2016-07-01

    Air plasma has been widely applied in industrial manufacture. In this paper, both dry and humid air plasmas' thermodynamic and transport properties are calculated in temperature 300-100000 K and pressure 0.1-100 atm. To build a more precise model of real air plasma, over 70 species are considered for composition. Two different methods, the Gibbs free energy minimization method and the mass action law method, are used to determinate the composition of the air plasma in a different temperature range. For the transport coefficients, the simplified Chapman-Enskog method developed by Devoto has been applied using the most recent collision integrals. It is found that the presence of CO2 has almost no effect on the properties of air plasma. The influence of H2O can be ignored except in low pressure air plasma, in which the saturated vapor pressure is relatively high. The results will serve as credible inputs for computational simulation of air plasma. supported by the National Key Basic Research Program of China (973 Program)(No. 2015CB251002), National Natural Science Foundation of China (Nos. 51521065, 51577145), the Science and Technology Project Funds of the Grid State Corporation (SGTYHT/13-JS-177), the Fundamental Research Funds for the Central Universities, and State Grid Corporation Project (GY71-14-004)

  10. Exploration of health risks related to air pollution and temperature in three Latin American cities

    NASA Astrophysics Data System (ADS)

    Romero-Lankao, P.; Borbor Cordova, M.; Qin, H.

    2013-12-01

    We explore whether the health risks related to air pollution and temperature extremes are spatially and socioeconomically differentiated within three Latin American cities: Bogota, Colombia, Mexico City, Mexico, and Santiago, Chile. Based on a theoretical review of three relevant approaches to risk analysis (risk society, environmental justice, and urban vulnerability as impact), we hypothesize that health risks from exposure to air pollution and temperature in these cities do not necessarily depend on socio-economic inequalities. To test this hypothesis, we gathered, validated, and analyzed temperature, air pollution, mortality and socioeconomic vulnerability data from the three study cities. Our results show the association between air pollution levels and socioeconomic vulnerabilities did not always correlate within the study cities. Furthermore, the spatial differences in socioeconomic vulnerabilities within cities do not necessarily correspond with the spatial distribution of health impacts. The present study improves our understanding of the multifaceted nature of health risks and vulnerabilities associated with global environmental change. The findings suggest that health risks from atmospheric conditions and pollutants exist without boundaries or social distinctions, even exhibiting characteristics of a boomerang effect (i.e., affecting rich and poor alike) on a smaller scale such as areas within urban regions. We used human mortality, a severe impact, to measure health risks from air pollution and extreme temperatures. Public health data of better quality (e.g., morbidity, hospital visits) are needed for future research to advance our understanding of the nature of health risks related to climate hazards.

  11. Global Distribution and Variability of Surface Skin and Surface Air Temperatures as Depicted in the AIRS Version-6 Data Set

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Lee, Jae N.; Iredell, Lena

    2014-01-01

    In this presentation, we will briefly describe the significant improvements made in the AIRS Version-6 retrieval algorithm, especially as to how they affect retrieved surface skin and surface air temperatures. The global distribution of seasonal 1:30 AM and 1:30 PM local time 12 year climatologies of Ts,a will be presented for the first time. We will also present the spatial distribution of short term 12 year anomaly trends of Ts,a at 1:30 AM and 1:30 PM, as well as the spatial distribution of temporal correlations of Ts,a with the El Nino Index. It will be shown that there are significant differences between the behavior of 1:30 AM and 1:30 PM Ts,a anomalies in some arid land areas.

  12. Changes in annual temperature and precipitation extremes in the Carpathians since AD 1961

    NASA Astrophysics Data System (ADS)

    Dumitrescu, Alexandru; Birsan, Marius-Victor; Magdalena Micu, Dana; Cheval, Sorin

    2014-05-01

    The Carpathians are the largest, longest, most twisted and fragmented segment of the Alpine system, stretching between latitudes 44°N and 50°N, and longitudes 17°E and 27°E. This European mountain range is a climatically transitional region between major atmospheric circulation source areas of the Atlantic Ocean, Mediterranean Sea and continental Europe. The region is a European biodiversity hotspot, containing over one third of all European plant species. It is acknowledged that the mountain regions are particularly sensitive and vulnerable to climate change than any other regions located at the same latitudes. Observational studies on the variability and trends of extreme events suggest an overall consensus towards a significant increase in the frequency, duration and intensity of warm extremes in most of these regions, including the Carpathians. 15 core indices, defined by the Expert Team on Climate Change Detection and Indices (ETCCDI), were computed in order to investigate the changes in annual temperature and precipitation extremes, based on their known relevance for the infrastructure, human health and tourism activities in these mountains. The indices were computed from gridded daily datasets of minimum and maximum temperature and precipitation at 0.1° resolution (~10 km), available online within the framework of the project CarpatClim (www.carpatclim-eu.org) for the period 1961-2010. Changes in the annual temperature and precipitation extremes in the last five decades have been identified with the Mann-Kendall non-parametric trend test, at the 90% significance level (two-tail test). The results show decreasing trends in cold-related thermal indices, especially in the number of frost days, and increasing trends in warm-related ones. No consistent trend in precipitation extremes has been found. There is a generally uniform signal of significant increasing trends in the frequency of summer days across the Carpathians, with no obvious differences between

  13. Quantifying the effect of air temperature in CPV modules under outdoor conditions

    NASA Astrophysics Data System (ADS)

    Fernández, Eduardo F.; Pérez-Higueras, P.; Almonacid, F.; García Loureiro, A. J.; Fernández, J. I.; Rodrigo, P.; Vidal, P. G.; Almonacid, G.

    2012-10-01

    CPV modules are influenced by incident irradiance, air temperature and incident spectrum. However, the study of these effects and the ability to quantify them individually is not easy and it is still under study. The aim of this paper is describe a procedure to study the influence of air temperature in the maximum power point independently of the incident irradiance and spectrum. Two different CPV modules have been studied during one year, the main conclusions and the differences in the behaviour of CPV modules under study will be given.

  14. Emissions of an AVCO Lycoming 0-320-DIAD air cooled light aircraft engine as a function of fuel-air ratio, timing, and air temperature and humidity

    NASA Technical Reports Server (NTRS)

    Meng, P. R.; Skorobatckyi, M.; Cosgrove, D. V.; Kempke, E. E., Jr.

    1976-01-01

    A carbureted aircraft engine was operated over a range of test conditions to establish the exhaust levels over the EPA seven-mode emissions cycle. Baseline (full rich production limit) exhaust emissions at an induction air temperature of 59 F and near zero relative humidity were 90 percent of the EPA standard for HC, 35 percent for NOx, and 161 percent for CO. Changes in ignition timing around the standard 25 deg BTDC from 30 deg BTDC to 20 deg BTDC had little effect on the exhaust emissions. Retarding the timing to 15 deg BTDC increased both the HC and CO emissions and decreased NOx emissions. HC and CO emissions decreased as the carburetor was leaned out, while NOx emissions increased. The EPA emission standards were marginally achieved at two leanout conditions. Variations in the quantity of cooling air flow over the engine had no effect on exhaust emissions. Temperature-humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased.

  15. Disentangling the confounding effects of PAR and air temperature on net ecosystem exchange in time and scale

    NASA Astrophysics Data System (ADS)

    yang, Z.; Chen, J.; Becker, R.; Chu, H.; Xie, J.; Shao, C.

    2013-12-01

    Net ecosystem exchange of CO2 (NEE) in temperate forests is modulated by microclimatic factors. The effects of those factors differ at different time scales and during different time periods. Some of them are correlated across a number of time scales, so their effects on NEE are confounded by each other. PAR and air temperature (Ta) are among the two most important drivers of NEE in temperate forests, and among the two most correlated microclimatic factors. PAR and Ta have similar daily, seasonal, and annual cycles. Their influence on NEE is confounded by each other and entangled together especially at those scales. In this study, we tried to disentangle the confounding effects of them on NEE at different time scales and during different time periods. To accomplish this objective, we applied the innovative spectral analysis techniques including Continuous Wavelet Transformation (CWT), Cross Wavelet Transformation (XWT), Wavelet Coherent (WTC), and Partial Wavelet Coherence (PWC) on seven years time series (2004-2010) of PAR, Ta and NEE from the Ohio Oak Openings site (N 41.5545°, W 83.8438°), USA for spectral analysis. We found that PAR is the major driver at short time scales (e.g. semidiurnal and daily) and Ta is the major driver at long time scales (e.g. seasonal and annual). At daily scale during growing seasons, PAR is anti-phase with NEE with no time delay while Ta lagged PAR about 2-3 hours, which could be explained by the strong dependence of photosynthesis on PAR and a 2-3 hours lags of the daily course of Ta to PAR. At daily scale during non-growing season, NEE has little variation and thus neither Ta nor PAR has high common wavelet power and significant coherence with NEE. At annual scale, Ta is anti-phase with NEE and PAR leads NEE about 34 days, which could be explained by the strong dependence of LAI dynamics on Ta and the lag between the LAI/biomass development and the progress of sunlight. We also found that NEE distributes most of its variation

  16. Measurement of temperature distributions in a methane-air flame by moire deflectometry

    SciTech Connect

    Bar-Ziv, E.; Sgulim, S.; Kafri, O.; Keren, E.

    1982-01-01

    The temperature mapping of an axially symmetric premixed methane-air flame was determined by moire deflectometry. From the analysis of the moire data detailed information on the temperature distribution is obtained. The radial profile of the temperature shows a minimum at the center of the flame which gradually disappears when proceeding downstream, as expected. The main advantage of moire deflectometry over other techniques is that the temperature distribution of the entire flame is obtained with no need for a three dimensional scanning. We have shown that the technique provides valuable and detailed information which could lead to a better understanding of combustion mechanisms. The limitations of the method are discussed.

  17. Combined land/sea surface-air-temperature trends, 1949-1972

    SciTech Connect

    Chen, R.S.

    1982-04-01

    A major deficiency in most previous studies of fluctuations in the earth's climate based on air temperature records has been the dearth of data from oceanic areas and the Southern Hemisphere. This study analyzes a unique collection of ship-based observations of surface air temperature assembled by the UK Meteorological Office in parallel with the station-based dataset developed by the National Center for Atmospheric Research from the publications World Weather Records and Monthly Climatic Data for the World. Based on this much more geographically comprehensive database, it is concluded that, during the 24-year period 1949 to 1972, no statistically significant warming or cooling trends were evident in the time series of globally averaged surface air temperature measurements. However, temperature trends did vary latitudinally, with significant cooling in northern extra-tropical latitudes, no trend in equatorial latitudes, and significant but not homogeneous warming in southern extra-tropical latitudes. Time series of air temperatures over land and sea exhibited qualitatively similar behavior over the period 1949 to 1972, indicative of both the comparable quality of the two datasets and the probable lack of significant widespread bias in the land-based measurements due to urban development. The results of this study underscore the need for dense and geographically comprehensive measurements from both land and ocean areas and from both hemispheres in analyzing the global behavior of the earth's climate.

  18. Models for obtaining daily global solar irradiation from air temperature data

    NASA Astrophysics Data System (ADS)

    Paulescu, M.; Fara, L.; Tulcan-Paulescu, E.

    2006-03-01

    The study presents a critical assessment of the possibility of global solar irradiation computation by using air temperature instead of sunshine duration with the classical Ångström equations. The reason for this approach comes from the fact that, although the air temperature is a worldwide measured meteorological parameter, this is rarely used in solar radiation estimation techniques. More than that, the literature is very silent concerning the testing of such models in Eastern Europe. Two new global solar irradiation models (to be called AEAT) related to solar irradiation under clear sky conditions and having the minimum and maximum daily air temperature as input parameters were tested and compared with others from the literature against data measured at five stations in Romania in the year 2000. The accuracy of AEAT is acceptable and comparable to that of the models which use sunshine duration or cloud amount as input parameters. Since temperature-based Ångström correlations are strongly sensitive to origin, the approach for AEAT as a tool for potential users is presented in detail. Additionally reported is a new method to increase the generality of AEAT concerning the extension of the geographical application area. Based on overall results it was concluded that air temperature successfully substitutes sunshine duration in the estimation of the available solar energy.

  19. Using Key Indicators To Guide Curriculum Review at a Community College. AIR 1989 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Heverly, Mary Ann

    Accepted guidelines for academic program review often clash with the needs of administrators, who require timely and frequent information for monitoring the quality of academic programs. A method is described for developing key indicators that permit annual scanning of all programs. The goal was to develop indicators that would flag programs…

  20. Sex Equity Research: Keeping the Campus Out of the Courtroom. AIR 1984 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Brown, Marilyn K.; And Others

    Sex equity research efforts undertaken by the Office of Institutional Studies at the University of Maryland at College Park are discussed. A plan was developed for examining salary differences at three distinct times: time of appointment, upon promotion and/or award of tenure, and at annual salary reviews. Salaries of male and female faculty…

  1. Temperature measurements behind reflected shock waves in air. [radiometric measurement of gas temperature in self-absorbing gas flow

    NASA Technical Reports Server (NTRS)

    Bader, J. B.; Nerem, R. M.; Dann, J. B.; Culp, M. A.

    1972-01-01

    A radiometric method for the measurement of gas temperature in self-absorbing gases has been applied in the study of shock tube generated flows. This method involves making two absolute intensity measurements at identical wavelengths, but for two different pathlengths in the same gas sample. Experimental results are presented for reflected shock waves in air at conditions corresponding to incident shock velocities from 7 to 10 km/s and an initial driven tube pressure of 1 torr. These results indicate that, with this technique, temperature measurements with an accuracy of + or - 5 percent can be carried out. The results also suggest certain facility related problems.

  2. CO2 CH4 flux Air temperature Soil temperature and Soil moisture, Barrow, Alaska 2013 ver. 1

    DOE Data Explorer

    Margaret Torn

    2015-01-14

    This dataset consists of field measurements of CO2 and CH4 flux, as well as soil properties made during 2013 in Areas A-D of Intensive Site 1 at the Next-Generation Ecosystem Experiments (NGEE) Arctic site near Barrow, Alaska. Included are i) measurements of CO2 and CH4 flux made from June to September (ii) Calculation of corresponding Gross Primary Productivity (GPP) and CH4 exchange (transparent minus opaque) between atmosphere and the ecosystem (ii) Measurements of Los Gatos Research (LGR) chamber air temperature made from June to September (ii) measurements of surface layer depth, type of surface layer, soil temperature and soil moisture from June to September.

  3. An Experimental Investigation Into the Temperature Profile of a Compliant Foil Air Bearing

    NASA Technical Reports Server (NTRS)

    Radil, Kevin; Zeszotek, Michelle

    2004-01-01

    A series of tests was performed to determine the internal temperature profile in a compliant bump-type foil journal air bearing operating at room temperature under various speeds and load conditions. The temperature profile was collected by instrumenting a foil bearing with nine, type K thermocouples arranged in the center and along the bearing s edges in order to measure local temperatures and estimate thermal gradients in the axial and circumferential directions. To facilitate the measurement of maximum temperatures from viscous shearing in the air film, the thermocouples were tack welded to the backside of the bumps that were in direct contact with the top foil. The mating journal was coated with a high temperature solid lubricant that, together with the bearing, underwent high temperature start-stop cycles to produce a smooth, steady-state run-in surface. Tests were conducted at speeds from 20 to 50 krpm and loads ranging from 9 to 222 N. The results indicate that, over the conditions tested, both journal rotational speed and radial load are responsible for heat generation with speed playing a more significant role in the magnitude of the temperatures. The temperature distribution was nearly symmetric about the bearing center at 20 and 30 krpm but became slightly skewed toward one side at 40 and 50 krpm. Surprisingly, the maximum temperatures did not occur at the bearing edge where the minimum film thickness is expected but rather in the middle of the bearing where analytical investigations have predicted the air film to be much thicker. Thermal gradients were common during testing and were strongest in the axial direction from the middle of the bearing to its edges, reaching 3.78 8C/mm. The temperature profile indicated the circumferential thermal gradients were negligible.

  4. Effects of a ceramic coating on metal temperatures of an air-cooled turbine vane

    NASA Astrophysics Data System (ADS)

    Gladden, H. J.; Liebert, C. H.

    1980-02-01

    The metal temperatures of air cooled turbine vanes both uncoated and coated with the NASA thermal barrier system were studied experimentally. Current and advanced gas turbine engine conditions were simulated at reduced temperatures and pressures. Airfoil metal temperatures were significantly reduced, both locally and on the average, by use of the the coating. However, at low gas Reynolds number, the ceramic coating tripped a laminar boundary layer on the suction surface, and the resulting higher heat flux increased the metal temperatures. Simulated coating loss was also investigated and shown to increase local metal temperatures. However, the metal temperatures in the leading edge region remained below those of the uncoated vane tested at similar conditions. Metal temperatures in the trailing edge region exceeded those of the uncoated vane.

  5. Measurements of surface air temperatures in Lombok with low cost miniature data loggers

    NASA Astrophysics Data System (ADS)

    Sudiarta, I. W.; Yadnya, M. S.; Mardiana, L.; Kuripan, I. N.

    2014-09-01

    The global warming and climate change are two of our major problems in this decade. Local impacts of global warming need to be investigated since it depends on local conditions. Understanding variability of local weather especially surface air temperature requires many observations, not only periodic but also covers large area. In this paper, we report our progress in developing low cost miniature data loggers for temperature measurements. The data loggers are based on microcontrollers ATMega8L and 10 kΩ thermistors. Calibration results in laboratory and in field have indicated that the temperature obtained by data loggers shows good agreement with thermometer readings. It is found that errors of temperature measurements are less than 0.3 °C. We have performed preliminary temperature measurements in Lombok Island using twenty data loggers for about one week duration. Temperature variation in Lombok shows localized temperature distribution that is affected by position and topography.

  6. Effects of a ceramic coating on metal temperatures of an air-cooled turbine vane

    NASA Technical Reports Server (NTRS)

    Gladden, H. J.; Liebert, C. H.

    1980-01-01

    The metal temperatures of air cooled turbine vanes both uncoated and coated with the NASA thermal barrier system were studied experimentally. Current and advanced gas turbine engine conditions were simulated at reduced temperatures and pressures. Airfoil metal temperatures were significantly reduced, both locally and on the average, by use of the the coating. However, at low gas Reynolds number, the ceramic coating tripped a laminar boundary layer on the suction surface, and the resulting higher heat flux increased the metal temperatures. Simulated coating loss was also investigated and shown to increase local metal temperatures. However, the metal temperatures in the leading edge region remained below those of the uncoated vane tested at similar conditions. Metal temperatures in the trailing edge region exceeded those of the uncoated vane.

  7. Long-Term Response of High-Elevation Lakes to Changes in Atmospheric Deposition and Air Temperature

    NASA Astrophysics Data System (ADS)

    Mast, M.; Turk, J. T.; Campbell, D. H.; Clow, D. W.; Ingersoll, G. P.

    2008-12-01

    High-elevation lakes are often sensitive indicators of environmental and climate change. Here we evaluate over two decades of water-quality data from a long-term monitoring network of remote high-mountain lakes in three Colorado wilderness areas. In two of the areas, lake sulfate concentrations have decreased by a factor of 2-3 times since the mid-1980s, which is consistent with declines in precipitation sulfate measured at 11 high-elevation NADP stations in Colorado. The downward trends in lake and precipitation chemistry are likely the result of regional declines in sulfate emissions from power plants and nonferrous metal smelters. By contrast, lake sulfate concentrations increased dramatically in the third wilderness area despite declines in atmospherically deposited sulfate. In lakes in these areas, sulfate is derived primarily from pyrite oxidation in contrast to the other wilderness areas where sulfate is dominated by atmospheric sources. It is hypothesized that the upward trend in sulfate reflects enhanced pyrite weathering caused by an increase in annual air temperature of about 2-degrees Celsius since the mid-1980's. These results indicate the water-quality response of remote lakes to improvements in air quality may be complicated by long-term changes in climate.

  8. Empirical Analysis of the Influence of Forest Extent on Annual and Seasonal Surface Temperatures for the Continental United States

    EPA Science Inventory

    Most scenario‐based climate modeling studies indicate that replacing temperate forest with cropland will promote cooling by reducing surface air temperatures. These results are inconsistent with fieldbased microclimate studies that have found that forests are cooler, wetter, and...

  9. Equatorial range limits of an intertidal ectotherm are more linked to water than air temperature.

    PubMed

    Seabra, Rui; Wethey, David S; Santos, António M; Gomes, Filipa; Lima, Fernando P

    2016-10-01

    As climate change is expected to impose increasing thermal stress on intertidal organisms, understanding the mechanisms by which body temperatures translate into major biogeographic patterns is of paramount importance. We exposed individuals of the limpet Patella vulgata Linnaeus, 1758, to realistic experimental treatments aimed at disentangling the contribution of water and air temperature for the buildup of thermal stress. Treatments were designed based on temperature data collected at the microhabitat level, from 15 shores along the Atlantic European coast spanning nearly 20° of latitude. Cardiac activity data indicated that thermal stress levels in P. vulgata are directly linked to elevated water temperature, while high air temperature is only stressful if water temperature is also high. In addition, the analysis of the link between population densities and thermal regimes at the studied locations suggests that the occurrence of elevated water temperature may represent a threshold P. vulgata is unable to tolerate. By combining projected temperatures with the temperature threshold identified, we show that climate change will likely result in the westward expansion of the historical distribution gap in the Bay of Biscay (southwest France), and northward contraction of the southern range limit in south Portugal. These findings suggest that even a minor relaxing of the upwelling off northwest Iberia could lead to a dramatic increase in thermal stress, with major consequences for the structure and functioning of the intertidal communities along Iberian rocky shores. PMID:27109165

  10. Cool Roofs in Guangzhou, China: Outdoor Air Temperature Reductions during Heat Waves and Typical Summer Conditions.

    PubMed

    Cao, Meichun; Rosado, Pablo; Lin, Zhaohui; Levinson, Ronnen; Millstein, Dev

    2015-12-15

    In this paper, we simulate temperature reductions during heat-wave events and during typical summer conditions from the installation of highly reflective "cool" roofs in the Chinese megacity of Guangzhou. We simulate temperature reductions during six of the strongest historical heat-wave events over the past decade, finding average urban midday temperature reductions of 1.2 °C. In comparison, we simulate 25 typical summer weeks between 2004 and 2008, finding average urban midday temperature reductions of 0.8 °C, indicating that air temperature sensitivity to urban albedo in Guangzhou varies with meteorological conditions. We find that roughly three-fourths of the variance in air temperature reductions across all episodes can be accounted for by a linear regression, including only three basic properties related to the meteorological conditions: mean daytime temperature, humidity, and ventilation to the greater Guangzhou urban area. While these results highlight the potential for cool roofs to mitigate peak temperatures during heat waves, the temperature reductions reported here are based on the upper bound case, which increases albedos of all roofs (but does not modify road albedo or wall albedo). PMID:26523605

  11. Effects of air and water temperatures on resting metabolism of auklets and other diving birds.

    PubMed

    Richman, Samantha E; Lovvorn, James R

    2011-01-01

    For small aquatic endotherms, heat loss while floating on water can be a dominant energy cost, and requires accurate estimation in energetics models for different species. We measured resting metabolic rate (RMR) in air and on water for a small diving bird, the Cassin's auklet (Ptychoramphus aleuticus), and compared these results to published data for other diving birds of diverse taxa and sizes. For 8 Cassin's auklets (~165 g), the lower critical temperature was higher on water (21 °C) than in air (16 °C). Lowest values of RMR (W kg⁻¹) averaged 19% higher on water (12.14 ± 3.14 SD) than in air (10.22 ± 1.43). At lower temperatures, RMR averaged 25% higher on water than in air, increasing with similar slope. RMR was higher on water than in air for alcids, cormorants, and small penguins but not for diving ducks, which appear exceptionally resistant to heat loss in water. Changes in RMR (W) with body mass either in air or on water were mostly linear over the 5- to 20-fold body mass ranges of alcids, diving ducks, and penguins, while cormorants showed no relationship of RMR with mass. The often large energetic effects of time spent floating on water can differ substantially among major taxa of diving birds, so that relevant estimates are critical to understanding their patterns of daily energy use. PMID:21527823

  12. GSOD Based Daily Global Mean Surface Temperature and Mean Sea Level Air Pressure (1982-2011)

    SciTech Connect

    Xuan Shi, Dali Wang

    2014-05-05

    This data product contains all the gridded data set at 1/4 degree resolution in ASCII format. Both mean temperature and mean sea level air pressure data are available. It also contains the GSOD data (1982-2011) from NOAA site, contains station number, location, temperature and pressures (sea level and station level). The data package also contains information related to the data processing methods

  13. Spatial distribution of air temperature in Toruń (Central Poland) and its causes

    NASA Astrophysics Data System (ADS)

    Przybylak, Rajmund; Uscka-Kowalkowska, Joanna; Araźny, Andrzej; Kejna, Marek; Kunz, Mieczysław; Maszewski, Rafał

    2015-09-01

    In this article, the results of an investigation into the air temperature pattern and development (including the urban heat island (UHI)) in Toruń (central Poland) are presented. For the analysis, daily mean temperature (Ti) as well as daily maximum (Tmax) and minimum (Tmin) temperatures for 2012 gathered for 20 sites, evenly distributed in the area of city, have been taken as source data. Additionally, in order to provide more extensive characteristics of the diversity of the air temperature in the study area, the diurnal temperature range (DTR) and the number of the so-called characteristic days were calculated as well. The impact of weather conditions (cloudiness and wind speed), atmospheric circulation, urban morphological parameters and land cover on the UHI in the study area was investigated. In Toruń, according to the present study, the average UHI intensity in 2012 was equal to 1.0 °C. The rise of cloudiness and wind speed led to a decrease of the magnitude of the UHI. Generally, in most cases, anticyclonic situations favour increased thermal contrast between rural and city areas, particularly in summer. Warm western circulation types significantly reduced temperature differences in the western side of the city and enlarged them in the eastern side of the city. Eastern cold types also have a similar influence on air temperature differences. Positive and statistically significant correlations have been found between the percentage of built-up areas (sealing factor) and air temperature. Conversely, sky view factor (SVF) reveals negative correlations which are statistically significant only for Tmin.

  14. Effects of light intensity light quality and air velocity on temperature in plant reproductive organs

    NASA Astrophysics Data System (ADS)

    Kitaya, Y.; Hirai, H.

    Excess temperature increase in plant reproductive organs such as anthers and stigmata could cause fertility impediments and thus produce sterile seeds under artificial lighting conditions in closed plant growth facilities There is a possibility that the aberration was caused by an excess increase in temperatures of reproductive organs in Bioregenerative Life Support Systems under microgravity conditions in space The fundamental study was conducted to know the thermal situation of the plant reproductive organs as affected by light intensity light quality and air velocity on the earth and to estimate the excess temperature increase in the reproductive organs in closed plant growth facilities in space Thermal images of reproductive organs of rice and strawberry were captured using infrared thermography at an air temperature of 10 r C The temperatures in flowers at 300 mu mol m -2 s -1 PPFD under the lights from red LEDs white LEDs blue LEDs fluorescent lamps and incandescent lamps increased by 1 4 1 7 1 9 6 0 and 25 3 r C respectively for rice and by 2 8 3 4 4 1 7 8 and 43 4 r C respectively for strawberry The flower temperatures increased with increasing PPFD levels The temperatures in petals anthers and stigmas of strawberry at 300 mu mol m -2 s -1 PPFD under incandescent lamps increased by 32 7 29 0 and 26 6 r C respectively at 0 1 m s -1 air velocity and by 20 6 18 5 and 15 9 r C respectively at 0 8 m s -1 air velocity The temperatures of reproductive organs decreased with increasing

  15. Relationships of eggshell, air cell, and cloacal temperatures of embryonated broiler hatching eggs during incubation.

    PubMed

    Olojede, O C; Collins, K E; Womack, S K; Gerard, P D; Peebles, E D

    2016-10-01

    The relationships of eggshell, air cell, and embryo cloacal temperatures in Ross × Ross 708 broiler hatching eggs were determined. Twenty eggs were weighed and set on each of 3 tray levels of a single incubator. Eggshell temperature (EST) of the eggs were recorded once in the morning (AM) and afternoon (PM) between 0 and 19 d of incubation (DOI) using an infrared thermometer (IRT). All eggs were candled and a transponder was implanted in the air cell of eggs containing live embryos (12 per tray level) at 12 DOI. At 19 DOI, transponders were implanted in the cloaca of live embryos from those same eggs. Air cell temperature (ACT) and EST readings were recorded once in the AM and PM between 12 and 19 DOI, and ACT and cloaca temperature (CLT) readings were recorded every 6 h between 19 and 21 DOI. The EST and ACT readings between 13 and 19 DOI were positively correlated. However, their respective mean temperatures between 13 and 19 DOI differed. The EST and ACT were not significantly influenced by tray level. Nevertheless, a main effect due to location (eggshell vs. air cell), and an interaction between DOI and time of day (AM and PM) in the 13 to 19 DOI interval were observed. Furthermore, an interaction was observed between location (air cell and cloaca) and the 6 h sequential time periods in the 19 to 21 DOI interval. However, across the entire 19 to 21 DOI interval, mean ACT and CLT were not significantly different, and were positively correlated. These data suggest that ACT readings are higher than those of EST during the last half of incubation, and that between 13 and 19 DOI, ACT readings may have the potential for use as a minimally invasive method by which to more accurately estimate the true core body temperature of broiler embryos. The effects of this method on hatchability and post-hatch performance need determination to better establish its practicality. PMID:27433009

  16. An Analytical Solution for Mechanical Responses Induced by Temperature and Air Pressure in a Lined Rock Cavern for Underground Compressed Air Energy Storage

    NASA Astrophysics Data System (ADS)

    Zhou, Shu-Wei; Xia, Cai-Chu; Du, Shi-Gui; Zhang, Ping-Yang; Zhou, Yu

    2015-03-01

    Mechanical responses induced by temperature and air pressure significantly affect the stability and durability of underground compressed air energy storage (CAES) in a lined rock cavern. An analytical solution for evaluating such responses is, thus, proposed in this paper. The lined cavern of interest consists of three layers, namely, a sealing layer, a concrete lining and the host rock. Governing equations for cavern temperature and air pressure, which involve heat transfer between the air and surrounding layers, are established first. Then, Laplace transform and superposition principle are applied to obtain the temperature around the lined cavern and the air pressure during the operational period. Afterwards, a thermo-elastic axisymmetrical model is used to analytically determine the stress and displacement variations induced by temperature and air pressure. The developments of temperature, displacement and stress during a typical operational cycle are discussed on the basis of the proposed approach. The approach is subsequently verified with a coupled compressed air and thermo-mechanical numerical simulation and by a previous study on temperature. Finally, the influence of temperature on total stress and displacement and the impact of the heat transfer coefficient are discussed. This paper shows that the temperature sharply fluctuates only on the sealing layer and the concrete lining. The resulting tensile hoop stresses on the sealing layer and concrete lining are considerably large in comparison with the initial air pressure. Moreover, temperature has a non-negligible effect on the lined cavern for underground compressed air storage. Meanwhile, temperature has a greater effect on hoop and longitudinal stress than on radial stress and displacement. In addition, the heat transfer coefficient affects the cavern stress to a higher degree than the displacement.

  17. Ambient temperature, air pollution, and heart rate variability in an aging population.

    PubMed

    Ren, Cizao; O'Neill, Marie S; Park, Sung Kyun; Sparrow, David; Vokonas, Pantel; Schwartz, Joel

    2011-05-01

    Studies show that ambient temperature and air pollution are associated with cardiovascular disease and that they may interact to affect cardiovascular events. However, few epidemiologic studies have examined mechanisms through which ambient temperature may influence cardiovascular function. The authors examined whether temperature was associated with heart rate variability (HRV) in a Boston, Massachusetts, study population and whether such associations were modified by ambient air pollution concentrations. The population was a cohort of 694 older men examined between 2000 and 2008. The authors fitted a mixed model to examine associations between temperature and air pollution and their interactions with repeated HRV measurements, adjusting for covariates selected a priori on the basis of their previous studies. Results showed that higher ambient temperature was associated with decreases in HRV measures (standard deviation of normal-to-normal intervals, low-frequency power, and high-frequency power) during the warm season but not during the cold season. These warm-season associations were significantly greater when ambient ozone levels were higher (>22.3 ppb) but did not differ according to levels of ambient fine (≤2.5 μm) particulate matter. The authors conclude that temperature and ozone, exposures to both of which are expected to increase with climate change, might act together to worsen cardiovascular health and/or precipitate cardiovascular events via autonomic nervous system dysfunction. PMID:21385834

  18. Leaf litter decomposition rates increase with rising mean annual temperature in Hawaiian tropical montane wet forests

    PubMed Central

    Bothwell, Lori D.; Giardina, Christian P.; Litton, Creighton M.

    2014-01-01

    Decomposing litter in forest ecosystems supplies nutrients to plants, carbon to heterotrophic soil microorganisms and is a large source of CO2 to the atmosphere. Despite its essential role in carbon and nutrient cycling, the temperature sensitivity of leaf litter decay in tropical forest ecosystems remains poorly resolved, especially in tropical montane wet forests where the warming trend may be amplified compared to tropical wet forests at lower elevations. We quantified leaf litter decomposition rates along a highly constrained 5.2 °C mean annual temperature (MAT) gradient in tropical montane wet forests on the Island of Hawaii. Dominant vegetation, substrate type and age, soil moisture, and disturbance history are all nearly constant across this gradient, allowing us to isolate the effect of rising MAT on leaf litter decomposition and nutrient release. Leaf litter decomposition rates were a positive linear function of MAT, causing the residence time of leaf litter on the forest floor to decline by ∼31 days for each 1 °C increase in MAT. Our estimate of the Q10 temperature coefficient for leaf litter decomposition was 2.17, within the commonly reported range for heterotrophic organic matter decomposition (1.5–2.5) across a broad range of ecosystems. The percentage of leaf litter nitrogen (N) remaining after six months declined linearly with increasing MAT from ∼88% of initial N at the coolest site to ∼74% at the warmest site. The lack of net N immobilization during all three litter collection periods at all MAT plots indicates that N was not limiting to leaf litter decomposition, regardless of temperature. These results suggest that leaf litter decay in tropical montane wet forests may be more sensitive to rising MAT than in tropical lowland wet forests, and that increased rates of N release from decomposing litter could delay or prevent progressive N limitation to net primary productivity with climate warming. PMID:25493213

  19. Responding to bioterror concerns by increasing milk pasteurization temperature would increase estimated annual deaths from listeriosis.

    PubMed

    Stasiewicz, Matthew J; Martin, Nicole; Laue, Shelley; Gröhn, Yrjo T; Boor, Kathryn J; Wiedmann, Martin

    2014-05-01

    In a 2005 analysis of a potential bioterror attack on the food supply involving a botulinum toxin release into the milk supply, the authors recommended adopting a toxin inactivation step during milk processing. In response, some dairy processors increased the times and temperatures of pasteurization well above the legal minimum for high temperature, short time pasteurization (72 °C for 15 s), with unknown implications for public health. The present study was conducted to determine whether an increase in high temperature, short time pasteurization temperature would affect the growth of Listeria monocytogenes, a potentially lethal foodborne pathogen normally eliminated with proper pasteurization but of concern when milk is contaminated postpasteurization. L. monocytogenes growth during refrigerated storage was higher in milk pasteurized at 82 °C than in milk pasteurized at 72 °C. Specifically, the time lag before exponential growth was decreased and the maximum population density was increased. The public health impact of this change in pasteurization was evaluated using a quantitative microbial risk assessment of deaths from listeriosis attributable to consumption of pasteurized fluid milk that was contaminated postprocessing. Conservative estimates of the effect of pasteurizing all fluid milk at 82 °C rather than 72 °C are that annual listeriosis deaths from consumption of this milk would increase from 18 to 670, a 38-fold increase (8.7- to 96-fold increase, 5th and 95th percentiles). These results exemplify a situation in which response to a rare bioterror threat may have the unintended consequence of putting the public at increased risk of a known, yet severe harm and illustrate the need for a paradigm shift toward multioutcome risk benefit analyses when proposing changes to established food safety practices. PMID:24780323

  20. Monitoring of binder removal from injection molded ceramics using air-coupled ultrasound at high temperature.

    PubMed

    Wright, W D; Hutchins, D A

    1999-01-01

    A pair of capacitance-type air-coupled ultrasonic transducers have been constructed that were capable of operating in air at temperatures of 500 to 600 degrees C. These devices were then used to monitor the pyrolytic removal of organic binder from injection molded silicon nitride ceramic components using air-coupled ultrasound inside a furnace at elevated temperatures. Through-thickness waveforms were obtained in the ceramic and compared with simultaneous measurements of the mass of the sample. Both the ultrasonic velocity and signal amplitudes could be used to monitor the change in mass of the injection molded ceramic, and other phenomena (such as softening and redistribution of the binder) were observed. PMID:18238465

  1. Using Satellite-Based Spatiotemporal Resolved Air Temperature Exposure to Study the Association between Ambient Air Temperature and Birth Outcomes in Massachusetts

    PubMed Central

    Melly, Steven J.; Coull, Brent A.; Nordio, Francesco; Schwartz, Joel D.

    2015-01-01

    Background Studies looking at air temperature (Ta) and birth outcomes are rare. Objectives We investigated the association between birth outcomes and daily Ta during various prenatal exposure periods in Massachusetts (USA) using both traditional Ta stations and modeled addresses. Methods We evaluated birth outcomes and average daily Ta during various prenatal exposure periods in Massachusetts (USA) using both traditional Ta stations and modeled address Ta. We used linear and logistic mixed models and accelerated failure time models to estimate associations between Ta and the following outcomes among live births > 22 weeks: term birth weight (≥ 37 weeks), low birth weight (LBW; < 2,500 g at term), gestational age, and preterm delivery (PT; < 37 weeks). Models were adjusted for individual-level socioeconomic status, traffic density, particulate matter ≤ 2.5 μm (PM2.5), random intercept for census tract, and mother’s health. Results Predicted Ta during multiple time windows before birth was negatively associated with birth weight: Average birth weight was 16.7 g lower (95% CI: –29.7, –3.7) in association with an interquartile range increase (8.4°C) in Ta during the last trimester. Ta over the entire pregnancy was positively associated with PT [odds ratio (OR) = 1.02; 95% CI: 1.00, 1.05] and LBW (OR = 1.04; 95% CI: 0.96, 1.13). Conclusions Ta during pregnancy was associated with lower birth weight and shorter gestational age in our study population. Citation Kloog I, Melly SJ, Coull BA, Nordio F, Schwartz JD. 2015. Using satellite-based spatiotemporal resolved air temperature exposure to study the association between ambient air temperature and birth outcomes in Massachusetts. Environ Health Perspect 123:1053–1058; http://dx.doi.org/10.1289/ehp.1308075 PMID:25850104

  2. Response of sugarcane sucrose yields to carbon dioxide enrichment and elevated air temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Four sugarcane cultivars (CP 72-2086, CP 73-1547, CP 88-1508, and CP 80-1827) were grown in elongated temperature-gradient greenhouses (TGG) at ambient or elevated carbon dioxide (CO2) of 360 or 720 µmol CO2 mol-1 air (ppm, mole fraction basis), respectively. Elevated CO2 was maintained by injection...

  3. Manage postharvest deficit irrigation of peach trees using canopy to air temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field study was conducted to use mid-day canopy to air temperature difference (delta T) to manage postharvest deficit irrigation of peach trees in San Joaquin Valley of California and its performance was evaluated. Delta T thresholds were selected, based on previous years’ stem water potential and...

  4. Application of 3-D Urbanization Index to Assess Impact of Urbanization on Air Temperature.

    PubMed

    Wu, Chih-Da; Lung, Shih-Chun Candice

    2016-01-01

    The lack of appropriate methodologies and indicators to quantify three-dimensional (3-D) building constructions poses challenges to authorities and urban planners when formulating polices to reduce health risks due to heat stress. This study evaluated the applicability of an innovative three-dimensional Urbanization Index (3DUI), based on remote sensing database, with a 5 m spatial resolution of 3-D man-made constructions to representing intra-urban variability of air temperature by assessing correlation of 3DUI with air temperature from a 3-D perspective. The results showed robust high correlation coefficients, ranging from 0.83 to 0.85, obtained within the 1,000 m circular buffer around weather stations regardless of season, year, or spatial location. Our findings demonstrated not only the strength of 3DUI in representing intra-urban air-temperature variability, but also its great potential for heat stress assessment within cities. In view of the maximum correlation between building volumes within the 1,000 m circular buffer and ambient air temperature, urban planning should consider setting ceilings for man-made construction volume in each 2 × 2 km(2) residential community for thermal environment regulation, especially in Asian metropolis with high population density in city centers. PMID:27079537

  5. Application of 3-D Urbanization Index to Assess Impact of Urbanization on Air Temperature

    PubMed Central

    Wu, Chih-Da; Lung, Shih-Chun Candice

    2016-01-01

    The lack of appropriate methodologies and indicators to quantify three-dimensional (3-D) building constructions poses challenges to authorities and urban planners when formulating polices to reduce health risks due to heat stress. This study evaluated the applicability of an innovative three-dimensional Urbanization Index (3DUI), based on remote sensing database, with a 5 m spatial resolution of 3-D man-made constructions to representing intra-urban variability of air temperature by assessing correlation of 3DUI with air temperature from a 3-D perspective. The results showed robust high correlation coefficients, ranging from 0.83 to 0.85, obtained within the 1,000 m circular buffer around weather stations regardless of season, year, or spatial location. Our findings demonstrated not only the strength of 3DUI in representing intra-urban air-temperature variability, but also its great potential for heat stress assessment within cities. In view of the maximum correlation between building volumes within the 1,000 m circular buffer and ambient air temperature, urban planning should consider setting ceilings for man-made construction volume in each 2 × 2 km2 residential community for thermal environment regulation, especially in Asian metropolis with high population density in city centers. PMID:27079537

  6. Application of 3-D Urbanization Index to Assess Impact of Urbanization on Air Temperature

    NASA Astrophysics Data System (ADS)

    Wu, Chih-Da; Lung, Shih-Chun Candice

    2016-04-01

    The lack of appropriate methodologies and indicators to quantify three-dimensional (3-D) building constructions poses challenges to authorities and urban planners when formulating polices to reduce health risks due to heat stress. This study evaluated the applicability of an innovative three-dimensional Urbanization Index (3DUI), based on remote sensing database, with a 5 m spatial resolution of 3-D man-made constructions to representing intra-urban variability of air temperature by assessing correlation of 3DUI with air temperature from a 3-D perspective. The results showed robust high correlation coefficients, ranging from 0.83 to 0.85, obtained within the 1,000 m circular buffer around weather stations regardless of season, year, or spatial location. Our findings demonstrated not only the strength of 3DUI in representing intra-urban air-temperature variability, but also its great potential for heat stress assessment within cities. In view of the maximum correlation between building volumes within the 1,000 m circular buffer and ambient air temperature, urban planning should consider setting ceilings for man-made construction volume in each 2 × 2 km2 residential community for thermal environment regulation, especially in Asian metropolis with high population density in city centers.

  7. Dynamical-statistical Forecasting of Seasonal Air Temperature Over European Part of Russia

    NASA Astrophysics Data System (ADS)

    Khan, V.

    2008-12-01

    The aim of the present study is to improve prediction of seasonal surface air temperature using outputs of 7 GCMs from Russia, Korea, USA, and Japan. Geographical regions in European part of Russia with identical pattern of variability of monthly air temperature were identified using one objective classification method. Averaged over each identified regions air temperatures from NCEP/DOE reanalysis dataset were used as a predictant matrix. Modified "Perfect Prognosis" method was served as forecasting approach. Consistent spatial patterns between forecasted by different models H-500 fields and smoothed reanalysis air temperature were found. EOF analysis was applied to these informative areas separately for negative and positive correlation patterns. The 1st EOF for each model corresponded to maximal ~80% explained variance of H-500, and the convergence of EOFs for positive correlation areas was higher then that for negative. Predictor data set was created selecting only 1st EOFs of H-500 of 7 input models. Stepwise multiple regression technique allowed selecting optimal two predictor variables. The results demonstrated improved forecast skill compared to separate model forecasts and multi-model mean forecasts. This study has been supported by RFBR grants 07-05-00740, 07-05-13591.

  8. Effects of building-roof cooling on flow and air temperature in urban street canyons

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Jin; Pardyjak, Eric; Kim, Do-Yong; Han, Kyoung-Soo; Kwon, Byung-Hyuk

    2014-05-01

    The effects of building-roof cooling on flow and air temperature in 3D urban street canyons are numerically investigated using a computational fluid dynamics (CFD) model. The aspect ratios of the building and street canyon considered are unity. For investigating the building-roof cooling effects, the building-roof temperatures are systematically changed. The traditional flow pattern including a portal vortex appears in the spanwise canyon. Compared with the case of the control run, there are minimal differences in flow pattern in the cases in which maximum building-roof cooling is considered. However, as the building roof becomes cooler, the mean kinetic energy increases and the air temperature decreases in the spanwise canyon. Building-roof cooling suppresses the upward and inward motions above the building roof, resultantly increasing the horizontal velocity near the roof level. The increase in wind velocity above the roof level intensifies the secondarily driven vortex circulation as well as the inward (outward) motion into (out of) the spanwise canyon. Finally, building-roof cooling reduces the air temperature in the spanwise canyon, supplying much relatively cool air from the streamwise canyon into the spanwise canyon.

  9. Cloud-induced uncertainties in AIRS and ECMWF temperature and specific humidity

    NASA Astrophysics Data System (ADS)

    Wong, Sun; Fetzer, Eric J.; Schreier, Mathias; Manipon, Gerald; Fishbein, Evan F.; Kahn, Brian H.; Yue, Qing; Irion, Fredrick W.

    2015-03-01

    The uncertainties of the Atmospheric Infrared Sounder (AIRS) Level 2 version 6 specific humidity (q) and temperature (T) retrievals are quantified as functions of cloud types by comparison against Integrated Global Radiosonde Archive radiosonde measurements. The cloud types contained in an AIRS/Advanced Microwave Sounding Unit footprint are identified by collocated Moderate Resolution Imaging Spectroradiometer retrieved cloud optical depth (COD) and cloud top pressure. We also report results of similar validation of q and T from European Centre for Medium-Range Weather Forecasts (ECMWF) forecasts (EC) and retrievals from the AIRS Neural Network (NNW), which are used as the initial state for AIRS V6 physical retrievals. Differences caused by the variation in the measurement locations and times are estimated using EC, and all the comparisons of data sets against radiosonde measurements are corrected by these estimated differences. We report in detail the validation results for AIRS GOOD quality control, which is used for the AIRS Level 3 climate products. AIRS GOOD quality q reduces the dry biases inherited from the NNW in the middle troposphere under thin clouds but enhances dry biases in thick clouds throughout the troposphere (reaching -30% at 850 hPa near deep convective clouds), likely because the information contained in AIRS retrievals is obtained in cloud-cleared areas or above clouds within the field of regard. EC has small moist biases (~5-10%), which are within the uncertainty of radiosonde measurements, in thin and high clouds. Temperature biases of all data are within ±1 K at altitudes above the 700 hPa level but increase with decreasing altitude. Cloud-cleared retrievals lead to large AIRS cold biases (reaching about -2 K) in the lower troposphere for large COD, enhancing the cold biases inherited from the NNW. Consequently, AIRS GOOD quality T root-mean-squared errors (RMSEs) are slightly smaller than the NNW errors in thin clouds (1.5-2.5 K) but

  10. A comparison of surface air temperature variability in three 1000-Yr. coupled ocean-atmosphere model integrations

    SciTech Connect

    Stouffer, R.J.; Hegerl, G.; Tett, S.

    2000-02-01

    This study compares the variability of surface air temperature in three long coupled ocean-atmosphere general circulation model integrations. It is shown that the annual mean climatology of the surface air temperatures (SAT) in all three models is realistic and the linear trends over the 1,000-yr integrations are small over most areas of the globe. Second, although there are notable differences among the models, the models' SAT variability is fairly realistic on annual to decadal timescales, both in terms of the geographical distribution and of the global mean values. A notable exception is the poor simulation of observed tropical Pacific variability. In the HadCM2 model, the tropical variability is overestimated, while in the GFDL and HAM3L models, it is underestimated. Also, the ENSO-related spectral peak in the globally averaged observed SAT differs from that in any of the models. The relatively low resolution required to integrate models for long time periods inhibits the successful simulation of the variability in this region. On timescales longer than a few decades, the largest variance in the models is generally located near sea ice margins in high latitudes, which are also regions of deep oceanic convection and variability related to variations in the thermohaline circulation. However, the exact geographical location of these maxima varies from model to model. The preferred patterns of interdecadal variability that are common to all three coupled models can be isolated by computing empirical orthogonal functions (EOFs) of all model data simultaneously using the common EOF technique. A comparison of the variance each model associated with these common EOF patterns shows that the models generally agree on the most prominent patterns of variability. However, the amplitudes of the dominant models of variability differ to some extent between the models and between the models and observations. For example, two of the models have a mode with relatively large

  11. Advances in Fast-response Acoustically Derived Air-temperature Measurements

    NASA Astrophysics Data System (ADS)

    Bogoev, I.; Jacobsen, L.; Horst, T. W.; Conrad, B.

    2015-12-01

    Fast-response accurate air-temperature measurements are required when estimating turbulent fluxes of heat, water and carbon dioxide by open-path eddy-covariance technique. In comparison with contact thermometers like thermocouples, ultra-sonic thermometers do not suffer from solar radiation loading, water vapor condensation and evaporative cooling effects. Consequently they have the potential to provide more accurate true air temperature measurements. The absolute accuracy of the ultrasonic thermometer is limited by the following parameters: the distance between the transducer pairs, transducer delays associated with the electrical-acoustic signal conversion that vary with temperature, components of the wind vector that are normal to the ultrasonic paths, and humidity.The distance between the transducer pairs is commonly obtained by coordinate measuring machine. Improved accuracy demonstrated in this study results from increased stiffness in the anemometer head to better maintain the ultrasonic path-length distances. To further improve accuracy and account for changes in transducer delays and distance as a function of temperature, these parameters are characterized in a zero-wind chamber over the entire operating temperature range. When the sonic anemometer is combined with a co-located fast-response water vapor analyzer, like in the IRGASON instrument, speed of sound can be compensated for humidity effects on a point-by-point basis resulting in a true fast-response air temperature measurement. Laboratory test results show that when the above steps are implemented in the calibration of the ultrasonic thermometer air-temperature accuracy better than ±0.5 degrees Celsius can be achieved over the entire operating range. The approach is also validated in a field inter-comparison with an aspirated thermistor probe mounted in a radiation shield.

  12. Annual and seasonal fCO2 and air-sea CO2 fluxes in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Lauvset, S. K.; Chierici, M.; Counillon, F.; Omar, A.; Nondal, G.; Johannessen, T.; Olsen, A.

    2013-03-01

    The Barents Sea is the strongest CO2 sink in the Arctic region, yet estimates of the air-sea CO2 flux in this area show a large span reflecting uncertainty as well as significant variability both seasonally and regionally. Here we use a previously unpublished data set of seawater CO2 fugacity (fCO2), and map these data over the western Barents Sea through multivariable linear regressions with SeaWiFS/MODIS remote sensing and TOPAZ model data fields. We find that two algorithms are necessary in order to cover the full seasonal cycle, mainly because not all proxy variables are available for the entire year, and because variability in fCO2 is driven by different mechanisms in summer and winter. A comprehensive skill assessment indicates that there is a good overall correspondence between observations and predictions. The algorithms are also validated using two independent data sets, with good results. The gridded fCO2 fields reveal tight links between water mass distribution and fCO2 in all months, and particularly in winter. The seasonal cycle show peaks in the total air-sea CO2 influx in May and September, caused by respectively biological drawdown of CO2 and low sea ice concentration leaving a large open water area. For 2007 the annual average air-sea CO2 flux is - 48 ± 5 gC m- 2, which is comparable to previous estimates.

  13. Variation of annual effective dose due to radon level in indoor air in Marwar region of Rajasthan, India

    NASA Astrophysics Data System (ADS)

    Rani, Asha; Mittal, Sudhir; Mehra, Rohit

    2015-08-01

    In the present work, indoor radon and thoron measurements have been carried out from different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India using RAD7, a solid state alpha detector. The radon and thoron concentration in indoor air varies from 8.75 to 61.25 Bq m-3 and 32.7 to 147.2 Bq m-3 with the mean value of 32 and 73 Bq m-3 respectively. The observed indoor radon concentration values are well below the action level recommended by International Commission on Radiological Protection (200-300 Bq m-3) and Environmental Protection Agency (148 Bq m-3). The survey reveals that the thoron concentration values in the indoor air are well within the International Commission on Radiological Protection (2005). The calculated total annual effective dose due to radon level in indoor air varies from 0.22 to 1.54 mSv y-1 with the mean value of 0.81 mSv y-1 which is less than even the lower limit of action level 3-10 mSv y-1 recommended by International Commission on Radiological Protection (2005).

  14. Variation of annual effective dose due to radon level in indoor air in Marwar region of Rajasthan, India

    SciTech Connect

    Rani, Asha; Mittal, Sudhir; Mehra, Rohit

    2015-08-28

    In the present work, indoor radon and thoron measurements have been carried out from different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India using RAD7, a solid state alpha detector. The radon and thoron concentration in indoor air varies from 8.75 to 61.25 Bq m{sup −3} and 32.7 to 147.2 Bq m{sup −3} with the mean value of 32 and 73 Bq m{sup −3} respectively. The observed indoor radon concentration values are well below the action level recommended by International Commission on Radiological Protection (200-300 Bq m{sup −3}) and Environmental Protection Agency (148 Bq m{sup −3}). The survey reveals that the thoron concentration values in the indoor air are well within the International Commission on Radiological Protection (2005). The calculated total annual effective dose due to radon level in indoor air varies from 0.22 to 1.54 mSv y{sup −1} with the mean value of 0.81 mSv y{sup −1} which is less than even the lower limit of action level 3-10 mSv y{sup −1} recommended by International Commission on Radiological Protection (2005)

  15. Effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding.

    PubMed

    Secilmis, Asli; Bulbul, Mehmet; Sari, Tugrul; Usumez, Aslihan

    2013-01-01

    The neodymium/yttrium-aluminum-garnet (Nd/YAG) laser has been suggested to repair broken prostheses in the mouth. This study investigated the effects of different dentin thicknesses and air cooling on pulpal temperature rise during laser welding. Three intact human maxillary molars were prepared for full-veneer crown. For each tooth, dentin thicknesses in mesiobuccal cusp was 2, 3, or 4 mm. Twenty dies were duplicated from each of the prepared teeth. For metal copings with 0.5-mm thickness, wax patterns were prepared with dip wax technique directly onto each of dies. All patterns were sprued and invested. The castings were made using a nickel-chromium alloy (Nicromed Premium, Neodontics). A hole with 0.5-mm diameter was prepared on the mesiobuccal cusp of each crown. The Nd/YAG laser (9.85 W; 1 Hz repetition rate; fluence, 1.230 J/cm(2); Fidelis Plus 3, Fotona) was used for welding with or without air cooling (n = 10). The temperature rise was measured in pulpal chamber with a J-type thermocouple wire that was connected to a data logger. Differences between start and highest temperature reading were taken, and temperature rise values were compared using two-way analysis of variance and Tukey's honestly significant difference tests (α = .05). Pulpal temperature rise varied significantly depending on the dentin thickness and air cooling (p < 0.05). The non-air cooling group induced significantly the highest temperature increases. There were no significant differences between 2- and 3-mm dentin thicknesses groups (p > 0.05); however, pulpal temperature rise was the lowest for 4-mm dentin thickness group (p < 0.05). The highest values of thermal increase were found in the pulp chamber (6.8°C) when no air cooling was used in 2-mm dentin thickness group. Laser welding on base metal castings with Nd/YAG laser can be applied with air cooling to avoid temperature rises known to adversely affect pulpal health when dentin thickness is 2 or 3 mm. PMID:22562450

  16. STUDY ON AIR INGRESS MITIGATION METHODS IN THE VERY HIGH TEMPERATURE GAS COOLED REACTOR (VHTR)

    SciTech Connect

    Chang H. Oh

    2011-03-01

    An air-ingress accident followed by a pipe break is considered as a critical event for a very high temperature gas-cooled reactor (VHTR). Following helium depressurization, it is anticipated that unless countermeasures are taken, air will enter the core through the break leading to oxidation of the in-core graphite structure. Thus, without mitigation features, this accident might lead to severe exothermic chemical reactions of graphite and oxygen. Under extreme circumstances, a loss of core structural integrity may occur along with excessive release of radiological inventory. Idaho National Laboratory under the auspices of the U.S. Department of Energy is performing research and development (R&D) that focuses on key phenomena important during challenging scenarios that may occur in the VHTR. Phenomena Identification and Ranking Table (PIRT) studies to date have identified the air ingress event, following on the heels of a VHTR depressurization, as very important (Oh et al. 2006, Schultz et al. 2006). Consequently, the development of advanced air ingress-related models and verification and validation (V&V) requirements are part of the experimental validation plan. This paper discusses about various air-ingress mitigation concepts applicable for the VHTRs. The study begins with identifying important factors (or phenomena) associated with the air-ingress accident by using a root-cause analysis. By preventing main causes of the important events identified in the root-cause diagram, the basic air-ingress mitigation ideas can be conceptually derived. The main concepts include (1) preventing structural degradation of graphite supporters; (2) preventing local stress concentration in the supporter; (3) preventing graphite oxidation; (4) preventing air ingress; (5) preventing density gradient driven flow; (4) preventing fluid density gradient; (5) preventing fluid temperature gradient; (6) preventing high temperature. Based on the basic concepts listed above, various air

  17. Temperature measurements in hypersonic air flows using laser-induced O2 fluorescence

    NASA Technical Reports Server (NTRS)

    Laufer, Gabriel; Mckenzie, Robert L.

    1988-01-01

    An investigation is reported of the use of laser-induced fluorescence on oxygen for the measurement of air temperature and its fluctuations owing to turbulence in hypersonic wind tunnel flows. The results show that for temperatures higher than 60 K and densities higher than 0.01 amagat, the uncertainty in the temperature measurement can be less than 2 percent if it is limited by photon-statistical noise. The measurement is unaffected by collisional quenching and, if the laser fluence is kept below 1.5 J/sq cm, it is also unaffected by nonlinear effects which are associated with depletion of the absorbing states.

  18. Fast tomographic measurements of temperature in an air plasma cutting torch

    NASA Astrophysics Data System (ADS)

    Hlína, J.; Šonský, J.; Gruber, J.; Cressault, Y.

    2016-03-01

    Temperatures in an air plasma jet were measured using a tomographic experimental arrangement providing time-resolved scans of plasma optical radiation in the spectral band 559-601 nm from two directions. The acquired data and subsequent processing yielded time-resolved temperature distributions in measurement planes perpendicular to the plasma jet axis with a temporal resolution of 1 μs. The measurement system and evaluation methods afforded detailed information about the influence of high-frequency ripple modulation of the arc current on plasma temperature.

  19. Air - water temperature relationships in the trout streams of southeastern Minnesota’s carbonate - sandstone landscape

    USGS Publications Warehouse

    Krider, Lori A.; Magner, Joseph A.; Perry, Jim; Vondracek, Bruce C.; Ferrington, Leonard C., Jr.

    2013-01-01

    Carbonate-sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface-water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater-fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air-water temperature relationships for 40 GWFS in southeastern Minnesota. A 40-stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R2 of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface-water dominated streams. Regression models for streams with high R2 values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater-fed systems, but will do so at a slower rate than surface-water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.

  20. INVESTIGATION OF A NOVEL AIR BRAZING COMPOSITION FOR HIGH-TEMPERATURE, OXIDATION-RESISTANT CERAMIC JOINING

    SciTech Connect

    Weil, K. Scott; Hardy, John S.; Darsell, Jens T.

    2004-01-30

    One of the challenges in developing a useful ceramic joining technique is in producing a joint that offers good strength under high temperature and highly oxidizing operating conditions. Unfortunately many of the commercially available active metal ceramic brazing alloys exhibit oxidation behaviors which are unacceptable for use in a high temperature application. We have developed a new approach to ceramic brazing, referred to as air brazing, that employs an oxide wetting agent dissolved in a molten noble metal solvent, in this case CuO in Ag, such that acceptable wetting behavior occurs on a number of ceramic substrates. In an effort to explore how to increase the operating temperature of this type of braze, we have investigated the effect of ternary palladium additions on the wetting characteristics of our standard Ag-CuO air braze composition

  1. Precipitation and Air Temperature Impact on Seasonal Variations of Groundwater Levels

    NASA Astrophysics Data System (ADS)

    Vitola, Ilva; Vircavs, Valdis; Abramenko, Kaspars; Lauva, Didzis; Veinbergs, Arturs

    2012-12-01

    The aim of this study is to clarify seasonal effects of precipitation and temperature on groundwater level changes in monitoring stations of the Latvia University of Agriculture - Mellupīte, Bērze and Auce. Groundwater regime and level fluctuations depend on climatic conditions such as precipitation intensity, evapotranspiration, surface runoff and drainage, as well as other hydrological factors. The relationship between precipitation, air temperature and groundwater level fluctuations could also lead and give different perspective of possible changes in groundwater quality. Using mathematical statistics and graphic-analytic methods it is concluded that autumn and winter precipitation has the dominant impact on groundwater level fluctuations, whereas spring and summer season fluctuations are more dependent on the air temperature.

  2. Determining Land Surface Temperature Relations with Land Use-Land Cover and Air Pollution

    NASA Astrophysics Data System (ADS)

    Kahya, Ceyhan; Bektas Balcik, Filiz; Burak Oztaner, Yasar; Guney, Burcu

    2016-04-01

    Rapid population growth in conjunction with unplanned urbanization, expansion, and encroachment into the limited agricultural fields and green areas have negative impacts on vegetated areas. Land Surface Temperature (LST), Urban Heat Islands (UHI) and air pollution are the most important environmental problems that the extensive part of the world suffers from. The main objective of this research is to investigate the relationship between LST, air pollution and Land Use-Land Cover (LULC) in Istanbul, using Landsat 8 OLI satellite image. Mono-window algorithm is used to compute LST from Landsat 8 TIR data. In order to determine the air pollution, in-situ measurements of particulate matter (PM10) of the same day as the Landsat 8 OLI satellite image are obtained. The results of this data are interpolated using the Inverse Distance Weighted (IDW) method and LULC categories of Istanbul were determined by using remote sensing indices. Error matrix was created for accuracy assessment. The relationship between LST, air pollution and LULC categories are determined by using regression analysis method. Keywords: Land Surface Temperature (LST), air pollution, Land Use-Land Cover (LULC), Istanbul

  3. Snow removal and ambient air temperature effects on forest soil temperatures in northern Vermont

    NASA Astrophysics Data System (ADS)

    Wang, D.; Decker, K. L.; Waite, C.; Scherbatskoy, T.

    2003-12-01

    We measured deciduous forest soil temperatures under control (unmanipulated) and snow-free (where snow is manually removed) conditions for four winters (at three soil depths) to determine effects of a snow cover reduction such as may occur as a result of climate change on Vermont forest soils. The four winters we studied were characterized as:`cold and snowy', `warm with low snow', `cold with low snow', and `cool with low snow'. Snow-free soils were colder than controls at 5 and 15 cm depth for all years, and at all depths in the two cold winters. Soil thermal variability generally decreased with both increased snow cover and soil depth. The effect of snow cover on soil freeze-thaw events was highly dependent on both the depth of snow and the soil temperature. Snow kept the soil warm and reduced soil temperature variability, but often this caused soil to remain near 0 deg C, resulting in more freeze-thaw events under snow at one or more soil depths. During the `cold snowy' winter, soils under snow had daily averages consistently >0 deg C, whereas snow-free soil temperatures commonly dropped below -3 deg C. During the `warm' year, temperatures of soil under snow were often lower than those of snow-free soils. The warmer winter resulted in less snow cover to insulate soil from freezing in the biologically active top 30 cm. The possible consequences of increased soil freezing include more root mortality and nutrient loss which would potentially alter ecosystem dynamics, decrease productivity of some tree species, and increase sugar maple mortality in northern hardwood forests.

  4. Influence of Air Temperature Difference on the Snow Melting Simulation of SWAT Model

    NASA Astrophysics Data System (ADS)

    YAN, Y.; Onishi, T.

    2013-12-01

    The temperature-index models are commonly used to simulate the snowmelt process in mountain areas because of its good performance, low data requirements, and computational simplicity. Widely used distributed hydrological model: Soil and Water Assessment Tool (SWAT) model is also using a temperature-index module. However, the lack of monitoring air temperature data still involves uncertainties and errors in its simulation performance especially in data sparse area. Thus, to evaluate the different air temperature data influence on the snow melt of the SWAT model, five different air temperature data are applied in two different Russia basins (Birobidjan basin and Malinovka basin). The data include the monitoring air temperature data (TM), NCEP reanalysis data (TNCEP), the dataset created by inverse distance weighted interpolation (IDW) method (TIDW), the dataset created by improved IDW method considering the elevation influence (TIDWEle), and the dataset created by using linear regression and MODIS Land Surface Temperature (LST) data (TLST). Among these data, the TLST , the TIDW and TIDWEle data have the higher spatial density, while the TNCEP and TM DATA have the most valid monitoring value for daily scale. The daily simulation results during the snow melting seasons (March, April and May) showed reasonable results in both test basins for all air temperature data. While R2 and NSE in Birobidjan basin are around 0.6, these values in Malinovka basin are over 0.75. Two methods: Generalized Likelihood Uncertainty Estimation (GLUE) and Sequential Uncertainty Fitting, version. 2 (SUFI-2) were used for model calibration and uncertainty analysis. The evolution index is p-factor which means the percentage of measured data bracketed by the 95% Prediction Uncertainty (95PPU). The TLST dataset always obtained the best results in both basins compared with other datasets. On the other hand, the two IDW based method get the worst results among all the scenarios. Totally, the

  5. Trend analysis of air temperature time series in Greece and their relationship with circulation using surface and satellite data: recent trends and an update to 2013

    NASA Astrophysics Data System (ADS)

    Feidas, H.

    2016-07-01

    In this paper, the surface and lower tropospheric temperature trends in Greece and their relationship to the atmospheric circulation for the period 1955-2013 were examined, updating the study of Feidas et al. (Theor Appl Climatol 79:185-208, 2004) for data observed during the 12-year period 2002-2013. The trend analysis is based on a combination of three statistical tests. The trends are now examined for all the seasonal time series, new atmospheric circulation indices were added in the analysis, and maps with the spatial distribution of correlation between air temperature and atmospheric circulation were constructed and analysed. The series updated to 2013 for 18 stations reveal a clearer positive trend than that found for the period 1955-2001 on both the annual and the seasonal timescales. The warming signal detected only in summer in the study of Feidas et al. (Theor Appl Climatol 79:185-208, 2004) has now intensified and spread in other seasons. This warming appears to be mainly caused by the very high temperatures in the last decade (after 2004) of the record. At the national scale, there is now a match between surface temperature trends in Greece and Northern Hemisphere (NH) but only for summer, spring and annual time series, which are the only time series presenting a statistically significant warming trend in Greece. Satellite-induced lower tropospheric temperatures now show a statistically significant tropospheric temperature warming trend for the period 1979-2013, for both areas (Greece and NH). Lower tropospheric and surface air temperatures for the same period (1979-2013) show a very good agreement, with differences only in winter and summer for Greece. The influence of atmospheric circulation on the temperature variability in Greece was also examined using two more circulation indices: the Eastern Mediterranean Pattern Index (EMPI) and the North-Sea Caspian Pattern Index (NCPI). EMPI and especially NCPI explain better now the temperature variance in

  6. Air temperature evolution during dry spells and its relation to prevailing soil moisture regimes

    NASA Astrophysics Data System (ADS)

    Schwingshackl, Clemens; Hirschi, Martin; Seneviratne, Sonia I.

    2015-04-01

    The complex interplay between land and atmosphere makes accurate climate predictions very challenging, in particular with respect to extreme events. More detailed investigations of the underlying dynamics, such as the identification of the drivers regulating the energy exchange at the land surface and the quantification of fluxes between soil and atmosphere over different land types, are thus necessary. The recently started DROUGHT-HEAT project (funded by the European Research Council) aims to provide better understanding of the processes governing the land-atmosphere exchange. In the first phase of the project, different datasets and methods are used to investigate major drivers of land-atmosphere dynamics leading to droughts and heatwaves. In the second phase, these findings will be used for reducing uncertainties and biases in earth system models. Finally, the third part of the project will focus on the application of the previous findings and use them for the attribution of extreme events to land processes and possible mitigation through land geoengineering. One of the major questions in land-atmosphere exchange is the relationship between air temperature and soil moisture. Different studies show that especially during dry spells soil moisture has a strong impact on air temperature and the amplification of hot extremes. Whereas in dry and wet soil moisture regimes variations in latent heat flux during rain-free periods are expected to be small, this is not the case in transitional soil moisture regimes: Due to decreasing soil moisture content latent heat flux reduces with time, which causes in turn an increase in sensible heat flux and, subsequently, higher air temperatures. The investigation of air temperature evolution during dry spells can thus help to detect different soil moisture regimes and to provide insights on the effect of different soil moisture levels on air temperature. Here we assess the underlying relationships using different observational and

  7. Data Assimilation Experiments using Quality Controlled AIRS Version 5 Temperature Soundings

    NASA Technical Reports Server (NTRS)

    Susskind, Joel

    2008-01-01

    The AIRS Science Team Version 5 retrieval algorithm has been finalized and is now operational at the Goddard DAAC in the processing (and reprocessing) of all AlRS data. Version 5 contains accurate case-by-case error estimates for most derived products, which are also used for quality control. We have conducted forecast impact experiments assimilating AlRS quality controlled temperature profiles using the NASA GEOS-5 data assimilation system, consisting of the NCEP GSI analysis coupled with the NASA FVGCM. Assimilation of quality controlled temperature profiles resulted in significantly improved forecast skill in both the Northern Hemisphere and Southern Hemisphere Extra-Tropics, compared to that obtained from analyses obtained when all data used operationally by NCEP except for AlRS data is assimilated. Experiments using different Quality Control thresholds for assimilation of AlRS temperature retrievals showed that a medium quality control threshold performed better than a tighter threshold, which provided better overall sounding accuracy; or a looser threshold, which provided better spatial coverage of accepted soundings. We are conducting more experiments to further optimize this balance of spatial coverage and sounding accuracy from the data assimilation perspective. In all cases, temperature soundings were assimilated well below cloud level in partially cloudy cases. The positive impact of assimilating AlRS derived atmospheric temperatures all but vanished when only AIRS stratospheric temperatures were assimilated. Forecast skill resulting from assimilation of AlRS radiances uncontaminated by clouds, instead of AlRS temperature soundings, was only slightly better than that resulting from assimilation of only stratospheric AlRS temperatures. This reduction in forecast skill is most likely the result of significant loss of tropospheric information when only AIRS radiances unaffected by clouds are used in the data assimilation process.

  8. Annually-resolved temperature reconstructions of the past 2000 years from Dome-Fuji, East Antarctica

    NASA Astrophysics Data System (ADS)

    Motizuki, Yuko; Takahashi, Kazuya; Nakai, Yoichi; Motoyama, Hideaki

    2016-04-01

    We present annually-resolved temperature and SST reconstructions of the past 2000 years based on water (oxygen and deuterium) isotope measurement on a shallow ice core drilled in 2010 at Dome Fuji station, East Antarctica. These time series records will be an essential contribution to the PAGES 2k project from sparse data area in Antarctica. Dome Fuji station is located on a summit of Dronning Maud Land at an altitude of 3810 m a.s.l. (above sea level) (77o19'01'' S, 39o42'12'' E) in East Antarctica. The 10 m depth mean snow temperature at Dome Fuji is ‑57.3oC1). The inland area around Dome Fuji has been recognized to be especially unique: The snow and ice there contain much stratospheric information. The direct evidence for this comes from tritium contents originated from the nuclear bomb tests in the 1960s; the tritium fallout at the Dome Fuji site is outstandingly high among 16 snow pit samples widely collected over Antarctica2). To date the concerned Dome Fuji ice core, we applied volcanic signature matching to transfer the West Antarctic Ice Sheet (WAIS) Divide ice core chronology constructed by annual layer counting as used in the study by Sigl et al. (2014)3). In our presentation, we confine ourselves to discuss the oscillation periodicity that we observed in the oxygen isotope record in our data: The periods of approximately 10, 20, and 200 years were found. We will present the time series analyses for this in detail, and will discuss the origin of this periodicity. References: 1) Kameda, T., Motoyama, H., Fujita, S., and Takahashi, S.: "Past temporal and spatial variability of surface mass balance at Dome Fuji", East Antarctica, by the stake method from 1995 to 2006, J. Glaciol., 54, 107-116, 2008. 2) Fourre, E., Jean-Baptiste, P., Dapoigny, A., Baumier, D., Petit, J.-R., and Jouzel, J.: "Past and recent tritium levels in Arctic and Antarctic polar caps", Earth Planet. Sc. Lett., 245, 56-64, 2006. 3) Sigl, M., J. McConnell, M. Toohey, M. Curran, S. Das

  9. Cost Analysis of an Air Brayton Receiver for a Solar Thermal Electric Power System in Selected Annual Production Volumes

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Pioneer Engineering and Manufacturing Company estimated the cost of manufacturing and Air Brayton Receiver for a Solar Thermal Electric Power System as designed by the AiResearch Division of the Garrett Corporation. Production costs were estimated at annual volumes of 100; 1,000; 5,000; 10,000; 50,000; 100,000 and 1,000,000 units. These costs included direct labor, direct material and manufacturing burden. A make or buy analysis was made of each part of each volume. At high volumes special fabrication concepts were used to reduce operation cycle times. All costs were estimated at an assumed 100% plant capacity. Economic feasibility determined the level of production at which special concepts were to be introduced. Estimated costs were based on the economics of the last half of 1980. Tooling and capital equipment costs were estimated for ach volume. Infrastructure and personnel requirements were also estimated.

  10. 1997 Idaho National Engineering and Environmental Laboratory (INEEL) National Emission Standards for Hazardous Air Pollutants (NESHAPs) -- Radionuclides annual report

    SciTech Connect

    1998-06-01

    Under Section 61.94 of Title 40, Code of Federal Regulations (CFR), Part 61, Subpart H, National Emission Standards for Emissions of Radionuclides Other Than Radon From Department of Energy Facilities, each Department of Energy (DOE) facility must submit an annual report documenting compliance. This report addresses the Section 61.94 reporting requirements for operations at the Idaho National Engineering and Environmental Laboratory (INEEL) for calendar year (CY) 1997. Section 1 of this report provides an overview of the INEEL facilities and a brief description of the radioactive materials and processes at the facilities. Section 2 identifies radioactive air effluent release points and diffuse sources at the INEEL and actual releases during 1997. Section 2 also describes the effluent control systems for each potential release point. Section 3 provides the methodology and EDE calculations for 1997 INEEL radioactive emissions.

  11. Air moisture control on ocean surface temperature, hidden key to the warm bias enigma

    NASA Astrophysics Data System (ADS)

    Hourdin, Frédéric; Gǎinusǎ-Bogdan, Alina; Braconnot, Pascale; Dufresne, Jean-Louis; Traore, Aboul-Khadre; Rio, Catherine

    2015-12-01

    The systematic overestimation by climate models of the surface temperature over the eastern tropical oceans is generally attributed to an insufficient oceanic cooling or to an underestimation of stratocumulus clouds. We show that surface evaporation contributes as much as clouds to the dispersion of the warm bias intensity in a multimodel simulations ensemble. The models with the largest warm biases are those with the highest surface heating by radiation and lowest evaporative cooling in atmospheric simulations with prescribed sea surface temperatures. Surface evaporation also controls the amplitude of the surface temperature response to this overestimated heating, when the atmosphere is coupled to an ocean. Evaporation increases with temperature both because of increasing saturation humidity and of an unexpected drying of the near-surface air. Both the origin of the bias and this temperature adjustment point to the key role of near-surface relative humidity and its control by the atmospheric model.

  12. Dynamic Stiffness and Damping Characteristics of a High-Temperature Air Foil Journal Bearing

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.; DellaCorte, Christopher; Valco, Mark J.; Prahl, Joseph M.; Heshmat, Hooshang

    2001-01-01

    Using a high-temperature optically based displacement measurement system, a foil air bearing's stiffness and damping characteristics were experimentally determined. Results were obtained over a range of modified Sommerfeld Number from 1.5E6 to 1.5E7, and at temperatures from 25 to 538 C. An Experimental procedure was developed comparing the error in two curve fitting functions to reveal different modes of physical behavior throughout the operating domain. The maximum change in dimensionless stiffness was 3.0E-2 to 6.5E-2 over the Sommerfeld Number range tested. Stiffness decreased with temperature by as much as a factor of two from 25 to 538 C. Dimensionless damping was a stronger function of Sommerfeld Number ranging from 20 to 300. The temperature effect on damping being more qualitative, showed the damping mechanism shifted from viscous type damping to frictional type as temperature increased.

  13. A method to assess the inter-annual weather-dependent variability in air pollution concentration and deposition based on weather typing

    NASA Astrophysics Data System (ADS)

    Pleijel, Håkan; Grundström, Maria; Karlsson, Gunilla Pihl; Karlsson, Per Erik; Chen, Deliang

    2016-02-01

    Annual anomalies in air pollutant concentrations, and deposition (bulk and throughfall) of sulphate, nitrate and ammonium, in the Gothenburg region, south-west Sweden, were correlated with optimized linear combinations of the yearly frequency of Lamb Weather Types (LWTs) to determine the extent to which the year-to-year variation in pollution exposure can be partly explained by weather related variability. Air concentrations of urban NO2, CO, PM10, as well as O3 at both an urban and a rural monitoring site, and the deposition of sulphate, nitrate and ammonium for the period 1997-2010 were included in the analysis. Linear detrending of the time series was performed to estimate trend-independent anomalies. These estimated anomalies were subtracted from observed annual values. Then the statistical significance of temporal trends with and without LWT adjustment was tested. For the pollutants studied, the annual anomaly was well correlated with the annual LWT combination (R2 in the range 0.52-0.90). Some negative (annual average [NO2], ammonia bulk deposition) or positive (average urban [O3]) temporal trends became statistically significant (p < 0.05) when the LWT adjustment was applied. In all the cases but one (NH4 throughfall, for which no temporal trend existed) the significance of temporal trends became stronger with LWT adjustment. For nitrate and ammonium, the LWT based adjustment explained a larger fraction of the inter-annual variation for bulk deposition than for throughfall. This is probably linked to the longer time scale of canopy related dry deposition processes influencing throughfall being explained to a lesser extent by LWTs than the meteorological factors controlling bulk deposition. The proposed novel methodology can be used by authorities responsible for air pollution management, and by researchers studying temporal trends in pollution, to evaluate e.g. the relative importance of changes in emissions and weather variability in annual air pollution

  14. Effects of Temperature, Humidity and Air Flow on Fungal Growth Rate on Loaded Ventilation Filters.

    PubMed

    Tang, W; Kuehn, T H; Simcik, Matt F

    2015-01-01

    This study compares the fungal growth ratio on loaded ventilation filters under various temperature, relative humidity (RH), and air flow conditions in a controlled laboratory setting. A new full-size commercial building ventilation filter was loaded with malt extract nutrients and conidia of Cladosporium sphaerospermum in an ASHRAE Standard 52.2 filter test facility. Small sections cut from this filter were incubated under the following conditions: constant room temperature and a high RH of 97%; sinusoidal temperature (with an amplitude of 10°C, an average of 23°C, and a period of 24 hr) and a mean RH of 97%; room temperature and step changes between 97% and 75% RH, 97% and 43% RH, and 97% and 11% RH every 12 hr. The biomass on the filter sections was measured using both an elution-culture method and by ergosterol assay immediately after loading and every 2 days up to 10 days after loading. Fungal growth was detected earlier using ergosterol content than with the elution-culture method. A student's t-test indicated that Cladosporium sphaerospermum grew better at the constant room temperature condition than at the sinusoidal temperature condition. By part-time exposure to dry environments, the fungal growth was reduced (75% and 43% RH) or even inhibited (11% RH). Additional loaded filters were installed in the wind tunnel at room temperature and an RH greater than 95% under one of two air flow test conditions: continuous air flow or air flow only 9 hr/day with a flow rate of 0.7 m(3)/s (filter media velocity 0.15 m/s). Swab tests and a tease mount method were used to detect fungal growth on the filters at day 0, 5, and 10. Fungal growth was detected for both test conditions, which indicates that when temperature and relative humidity are optimum, controlling the air flow alone cannot prevent fungal growth. In real applications where nutrients are less sufficient than in this laboratory study, fungal growth rate may be reduced under the same operating conditions

  15. Rapid fluctuations of the air and surface temperature in the city of Bucharest (Romania)

    NASA Astrophysics Data System (ADS)

    Cheval, Sorin; Dumitrescu, Alexandru; Hustiu, Mihaita-Cristinel

    2016-04-01

    Urban areas derive significant changes of the ambient temperature generating specific challenges for society and infrastructure. Extreme temperature events, heat and cold waves affect the human comfort, increase the health risk, and require specific building regulations and emergency preparedness, strongly related to the magnitude and frequency of the thermal hazards. Rapid changes of the temperature put a particular stress for the urban settlements, and the topic has been approached constantly in the scientific literature. Due to its geographical position in a plain area with a temperate climate and noticeable continental influence, the city of Bucharest (Romania) deals with high seasonal and daily temperature variations. However, rapid fluctuations also occur at sub-daily scale caused by cold or warm air advections or by very local effects (e.g. radiative heat exchange, local precipitation). For example, in the area of Bucharest, the cold fronts of the warm season may trigger temperature decreasing up to 10-15 centigrades / hour, while warm advections lead to increasing of 1-2 centigrades / hour. This study focuses on the hourly and sub-hourly temperature variations over the period November 2014 - February 2016, using air temperature data collected from urban sensors and meteorological stations of the national network, and land surface temperature data obtained from satellite remote sensing. The analysis returns different statistics, such as magnitude, intensity, frequency, simultaneous occurrence and areal coverage of the rapid temperature fluctuations. Furthermore, the generating factors for each case study are assessed, and the results are used to define some preliminary patterns and enhance the urban temperature forecast at fine scale. The study was funded by the Romanian Programme Partnership in Priority Domains, PN - II - PCCA - 2013 - 4 - 0509 - Reducing UHI effects to improve urban comfort and balance energy consumption in Bucharest (REDBHI).

  16. An improved method for correction of air temperature measured using different radiation shields

    NASA Astrophysics Data System (ADS)

    Cheng, Xinghong; Su, Debin; Li, Deping; Chen, Lu; Xu, Wenjing; Yang, Meilin; Li, Yongcheng; Yue, Zhizhong; Wang, Zijing

    2014-11-01

    The variation of air temperature measurement errors using two different radiation shields (DTR502B Vaisala, Finland, and HYTFZ01, Huayun Tongda Satcom, China) was studied. Datasets were collected in the field at the Daxing weather station in Beijing from June 2011 to May 2012. Most air temperature values obtained with these two commonly used radiation shields were lower than the reference records obtained with the new Fiber Reinforced Polymers (FRP) Stevenson screen. In most cases, the air temperature errors when using the two devices were smaller on overcast and rainy days than on sunny days; and smaller when using the imported rather than the Chinese shield. The measured errors changed sharply at sunrise and sunset, and reached maxima at noon. Their diurnal variation characteristics were, naturally, related to changes in solar radiation. The relationships between the record errors, global radiation, and wind speed were nonlinear. An improved correction method was proposed based on the approach described by Nakamura and Mahrt (2005) (NM05), in which the impact of the solar zenith angle (SZA) on the temperature error is considered and extreme errors due to changes in SZA can be corrected effectively. Measurement errors were reduced significantly after correction by either method for both shields. The error reduction rate using the improved correction method for the Chinese and imported shields were 3.3% and 40.4% higher than those using the NM05 method, respectively.

  17. Hybridized electromagnetic-triboelectric nanogenerator for scavenging air-flow energy to sustainably power temperature sensors.

    PubMed

    Wang, Xue; Wang, Shuhua; Yang, Ya; Wang, Zhong Lin

    2015-04-28

    We report a hybridized nanogenerator with dimensions of 6.7 cm × 4.5 cm × 2 cm and a weight of 42.3 g that consists of two triboelectric nanogenerators (TENGs) and two electromagnetic generators (EMGs) for scavenging air-flow energy. Under an air-flow speed of about 18 m/s, the hybridized nanogenerator can deliver largest output powers of 3.5 mW for one TENG (in correspondence of power per unit mass/volume: 8.8 mW/g and 14.6 kW/m(3)) at a loading resistance of 3 MΩ and 1.8 mW for one EMG (in correspondence of power per unit mass/volume: 0.3 mW/g and 0.4 kW/m(3)) at a loading resistance of 2 kΩ, respectively. The hybridized nanogenerator can be utilized to charge a capacitor of 3300 μF to sustainably power four temperature sensors for realizing self-powered temperature sensor networks. Moreover, a wireless temperature sensor driven by a hybridized nanogenerator charged Li-ion battery can work well to send the temperature data to a receiver/computer at a distance of 1.5 m. This work takes a significant step toward air-flow energy harvesting and its potential applications in self-powered wireless sensor networks. PMID:25844537

  18. Short-term Effects of Air Temperature on Blood Markers of Coagulation and Inflammation in Potentially Susceptible Individuals

    EPA Science Inventory

    Objectives: Changes in air temperature are associated with an increase in cardiovascular events, but the role of pro-coagulant and pro-inflammatory blood markers is still poorly understood. We investigated the association between air temperature and fibrinogen, plasminogen act...

  19. The impact of humidity on evaporative cooling in small desert birds exposed to high air temperatures.

    PubMed

    Gerson, Alexander R; Smith, Eric Krabbe; Smit, Ben; McKechnie, Andrew E; Wolf, Blair O

    2014-01-01

    Environmental temperatures that exceed body temperature (Tb) force endothermic animals to rely solely on evaporative cooling to dissipate heat. However, evaporative heat dissipation can be drastically reduced by environmental humidity, imposing a thermoregulatory challenge. The goal of this study was to investigate the effects of humidity on the thermoregulation of desert birds and to compare the sensitivity of cutaneous and respiratory evaporation to reduced vapor density gradients. Rates of evaporative water loss, metabolic rate, and Tb were measured in birds exposed to humidities ranging from ∼2 to 30 g H2O m(-3) (0%-100% relative humidity at 30°C) at air temperatures between 44° and 56°C. In sociable weavers, a species that dissipates heat primarily through panting, rates of evaporative water loss were inhibited by as much as 36% by high humidity at 48°C, and these birds showed a high degree of hyperthermia. At lower temperatures (40°-44°C), evaporative water loss was largely unaffected by humidity in this species. In Namaqua doves, which primarily use cutaneous evaporation, increasing humidity reduced rates of evaporative water loss, but overall rates of water loss were lower than those observed in sociable weavers. Our data suggest that cutaneous evaporation is more efficient than panting, requiring less water to maintain Tb at a given temperature, but panting appears less sensitive to humidity over the air temperature range investigated here. PMID:25461643

  20. The EUSTACE break-detection algorithm for a global air temperature dataset

    NASA Astrophysics Data System (ADS)

    Brugnara, Yuri; Auchmann, Renate; Brönnimann, Stefan

    2016-04-01

    EUSTACE (EU Surface Temperature for All Corners of Earth) is an EU-funded project that has started in 2015; its goal is to produce daily estimates of surface air temperature since 1850 across the globe for the first time by combining surface and satellite data using novel statistical techniques. For land surface data (LSAT), we assembled a global dataset of ca. 35000 stations where daily maximum and minimum air temperature observations are available, taking advantage of the most recent data rescue initiatives. Beside quantity, data quality also plays an important role for the success of the project; in particular, the assessment of the homogeneity of the temperature series is crucial in order to obtain a product suitable for the study of climate change. This poster describes a fully automatic state-of-the-art break-detection algorithm that we developed for the global LSAT dataset. We evaluate the performance of the method using artificial benchmarks and present various statistics related to frequency and amplitude of the inhomogeneities detected in the real data. We show in particular that long-term temperature trends calculated from raw data are more often underestimated than overestimated and that this behaviour is mostly related to inhomogeneities affecting maximum temperatures.

  1. Consequences of a small decrease of air temperature from thermal equilibrium on thermoregulation in sleeping neonates.

    PubMed

    Telliez, F; Bach, V; Krim, G; Libert, J P

    1997-09-01

    A new heating unit (servocontrolled skin temperature derivative system) has been designed to control the thermal environment in closed incubators. This type of control acts to attain and closely maintain a thermal equilibrium between a neonate's skin temperature and the environment. The present study aims to discover if thermal equilibrium is located within a thermoneutral range defined from oxygen consumption VO2 and body temperature, and whether it is more appropriate to define an optimal thermal environment. As regards VO2 and body temperature, results show that the air temperature reached at thermal equilibrium fulfils the definition of thermoneutrality. According to these criteria, a small decrease (1:5 degrees C) from thermal equilibrium also provides a near thermoneutral environment to the neonate but induces sleep disturbances and an increase in body movements. These two additional parameters delineate a narrower thermoneutral zone than does minimal metabolic rate because VO2 can stay constant even when air and body temperatures decrease. The results suggest that thermal equilibrium might be assimilated with a thermal comfort zone. PMID:9374057

  2. A hierarchical model of daily stream temperature using air-water temperature synchronization, autocorrelation, and time lags

    USGS Publications Warehouse

    Letcher, Benjamin; Hocking, Daniel; O'Neill, K.; Whiteley, Andrew R.; Nislow, Keith H.; O'Donnell, Matthew

    2016-01-01

    Water temperature is a primary driver of stream ecosystems and commonly forms the basis of stream classifications. Robust models of stream temperature are critical as the climate changes, but estimating daily stream temperature poses several important challenges. We developed a statistical model that accounts for many challenges that can make stream temperature estimation difficult. Our model identifies the yearly period when air and water temperature are synchronized, accommodates hysteresis, incorporates time lags, deals with missing data and autocorrelation and can include external drivers. In a small stream network, the model performed well (RMSE = 0.59 °C), identified a clear warming trend (0.63 °C · decade-1) and a widening of the synchronized period (29 d · decade-1). We also carefully evaluated how missing data influenced predictions. Missing data within a year had a small effect on performance (~ 0.05% average drop in RMSE with 10% fewer days with data). Missing all data for a year decreased performance (~ 0.6 °C jump in RMSE), but this decrease was moderated when data were available from other streams in the network.

  3. A hierarchical model of daily stream temperature using air-water temperature synchronization, autocorrelation, and time lags.

    PubMed

    Letcher, Benjamin H; Hocking, Daniel J; O'Neil, Kyle; Whiteley, Andrew R; Nislow, Keith H; O'Donnell, Matthew J

    2016-01-01

    Water temperature is a primary driver of stream ecosystems and commonly forms the basis of stream classifications. Robust models of stream temperature are critical as the climate changes, but estimating daily stream temperature poses several important challenges. We developed a statistical model that accounts for many challenges that can make stream temperature estimation difficult. Our model identifies the yearly period when air and water temperature are synchronized, accommodates hysteresis, incorporates time lags, deals with missing data and autocorrelation and can include external drivers. In a small stream network, the model performed well (RMSE = 0.59°C), identified a clear warming trend (0.63 °C decade(-1)) and a widening of the synchronized period (29 d decade(-1)). We also carefully evaluated how missing data influenced predictions. Missing data within a year had a small effect on performance (∼0.05% average drop in RMSE with 10% fewer days with data). Missing all data for a year decreased performance (∼0.6 °C jump in RMSE), but this decrease was moderated when data were available from other streams in the network. PMID:26966662

  4. A hierarchical model of daily stream temperature using air-water temperature synchronization, autocorrelation, and time lags

    PubMed Central

    Hocking, Daniel J.; O’Neil, Kyle; Whiteley, Andrew R.; Nislow, Keith H.; O’Donnell, Matthew J.

    2016-01-01

    Water temperature is a primary driver of stream ecosystems and commonly forms the basis of stream classifications. Robust models of stream temperature are critical as the climate changes, but estimating daily stream temperature poses several important challenges. We developed a statistical model that accounts for many challenges that can make stream temperature estimation difficult. Our model identifies the yearly period when air and water temperature are synchronized, accommodates hysteresis, incorporates time lags, deals with missing data and autocorrelation and can include external drivers. In a small stream network, the model performed well (RMSE = 0.59°C), identified a clear warming trend (0.63 °C decade−1) and a widening of the synchronized period (29 d decade−1). We also carefully evaluated how missing data influenced predictions. Missing data within a year had a small effect on performance (∼0.05% average drop in RMSE with 10% fewer days with data). Missing all data for a year decreased performance (∼0.6 °C jump in RMSE), but this decrease was moderated when data were available from other streams in the network. PMID:26966662

  5. High Temperature Materials Laboratory, Eleventh Annual Report: October 1997 through September 1998

    SciTech Connect

    Pasto, A.E.; Russell, B.J.

    2000-03-01

    The High Temperature Materials Laboratory (HTML) has completed its eleventh year of operation as a designated US Department of Energy User Facility at the Oak Ridge National Laboratory. This document profiles the historical growth of the HTML User and Fellowship Programs since their inception in 1987. Growth of the HTML programs has been demonstrated by the number of institutions executing user agreements and by the number of days of instrument use (user days) since the HTML began operation.A total of 522 agreements (351 industry,156 university,and 15 other federal agency) are now in effect (452 nonproprietary and 70 proprietary). This represents an increase of 75 user agreements since the last reporting period (for FY 1997). A state-by-state summary of the nonproprietary user agreements is given in Appendix A. Forty-six states are represented. During FY 1998, the HTML User Program evaluated 80 nonproprietary proposals (32 from industry, 45 from universities, and 3 from other government facilities) and several proprietary proposals. Appendix B provides a detailed breakdown of the nonproprietary proposals received during FY 1998. The HTML User Advisory Committee approved about 95% of those proposals, sometimes after the prospective user revised the proposal based on comments from the committee. This annual report discusses activities in the individual user centers as well as plans for the future. It also gives statistics about users, proposals, and publications as well as summaries of the nonproprietary research projects active during 1998.

  6. High Temperature Materials Laboratory seventh annual report, October 1993--September 1994

    SciTech Connect

    Tennery, V.J.; Teague, P.A.

    1994-12-01

    The High Temperature Materials Laboratory (HTML) has completed its seventh year of operation as a designated Department of Energy User Facility at the Oak Ridge National Laboratory. Growth of the User Program has been demonstrated by the number of institutions executing user agreements since the HTML began operation in 1987. A total of 193 nonproprietary agreements (91 industry and 102 university) and 41 proprietary agreements (39 industry and two university) are now in effect. This represents an increase of 21 nonproprietary user agreements during FY 1994. Forty-one states are represented by these users. During FY 1994, the HTML User Program evaluated 106 nonproprietary proposals (46 from industry, 52 from universities, and 8 from other government facilities) and 8 proprietary proposals. The HTML User Advisory Committee approved about ninety-five percent of those evaluated proposals, sometimes after the prospective user revised the proposal based on comments from the Committee. This annual report discusses FY 1994 activities in the individual user centers, as well as plans for the future. It also gives statistics about users and their proposals and FY 1994 publications, and summarizes nonproprietary research projects active in FY 1994.

  7. High Temperature Materials Laboratory eight and ninth annual reports, October 1994 through September 1996

    SciTech Connect

    Pasto, A.E.; Russell, B.J.

    1997-10-01

    The High Temperature Materials Laboratory (HTML) has completed its ninth year of operation as a designated US Department of Energy User Facility at the Oak Ridge National Laboratory. This document profiles the historical growth of the HTML User and Fellowship Programs since their inception in 1987. Growth of the HTML programs has been demonstrated by the number of institutions executing user agreements, and by the number of days of instrument use (user days) since the HTML began operation. A total of 276 nonproprietary agreements (135 industry, 135 university, and 6 other federal agency) and 56 proprietary agreements are now in effect. This represents an increase of 70 nonproprietary user agreements since the last reporting period (for FY 1994). A state-by-state summary of these nonproprietary user agreements is given in Appendix A, and an alphabetical listing is provided in Appendix B. Forty-four states are represented by these users. During FY 1995 and 1996, the HTML User Program evaluated 145 nonproprietary proposals (62 from industry, 82 from universities, and 1 from other government facilities) and several proprietary proposals. The HTML User Advisory Committee approved about 95% of those proposals, frequently after the prospective user revised the proposal based on comments from the committee. This annual report discusses activities in the individual user centers, as well as plans for the future. It also gives statistics about users, proposals, and publications as well as summaries of the nonproprietary research projects active during 1995 and 1996.

  8. High Temperature Materials Laboratory Thirteenth Annual Report: October 1999 Through September 2000

    SciTech Connect

    Pasto, AE

    2001-11-07

    The High Temperature Materials Laboratory (HTML) User Program continued to work with industrial, academic, and governmental users this year, accepting 86 new projects and developing 50 new user agreements. The table on the following page presents the breakdown of these statistics. The figure on page 2 depicts the continued growth in user agreements and user projects. You may note that our total number of proposals is nearing 1000, and we expect to achieve this number in our first proposal review meeting of FY 2001. The large number of new agreements bodes well for the future. A list of proposals to the HTML follows this section; at the end of the report, we present a list of agreements between HTML and universities and industries, broken down by state. Program highlights this year included several outstanding user projects (some of which are discussed in later sections), the annual meeting of the HTML Programs Senior Advisory Committee, the completion of a formal Multiyear Program Plan (MYPP), and finalization of a purchase agreement with JEOL for a new-generation electron microscope.

  9. Variation of the shower lateral spread with air temperature at the ground

    NASA Astrophysics Data System (ADS)

    Wilczyńska, B.; Engel, R.; Homola, P.; Keilhauer, B.; Klages, H.; Pękala, J.; Wilczyński, H.

    The vertical profile of air density at a given site varies considerably with time. Well understood seasonal differences are present, but sizeable effects on shorter time scales, like day to night or day to day variations, are also observed. In consequence, the Moliere radius changes, influencing the lateral distribution of particles in the air showers and therefore may influence the shower detection in surface detector arrays. In air shower reconstruction, usually seasonal average profiles of the atmosphere are used, because local daily measurements of the profile are rarely available. Therefore, the daily fluctuations of the atmosphere are not accounted for. This simplification increases the inaccuracies of shower reconstruction. We show that a universal correlation exists between the ground temperature and the shape of the atmospheric profile, up to altitudes of several kilometers, hence providing a method to reduce inaccuracies in shower reconstruction due to weather variation.

  10. Dynamics of air temperature, velocity and ammonia emissions in enclosed and conventional pig housing systems.

    PubMed

    Song, J I; Park, K-H; Jeon, J H; Choi, H L; Barroga, A J

    2013-03-01

    This study aimed to compare the dynamics of air temperature and velocity under two different ventilation and housing systems during summer and winter in Korea. The NH3 concentration of both housing systems was also investigated in relation to the pig's growth. The ventilation systems used were; negative pressure type for the enclosed pig house (EPH) and natural airflow for the conventional pig house (CPH). Against a highly fluctuating outdoor temperature, the EPH was able to maintain a stable temperature at 24.8 to 29.1°C during summer and 17.9 to 23.1°C during winter whilst the CPH had a wider temperature variance during summer at 24.7 to 32.3°C. However, the temperature fluctuation of the CPH during winter was almost the same with that of EPH at 14.5 to 18.2°C. The NH3 levels in the CPH ranged from 9.31 to 16.9 mg/L during summer and 5.1 to 19.7 mg/L during winter whilst that of the EPH pig house was 7.9 to 16.1 mg/L and 3.7 to 9.6 mg/L during summer and winter, respectively. These values were less than the critical ammonia level for pigs with the EPH maintaining a lower level than the CPH in both winter and summer. The air velocity at pig nose level in the EPH during summer was 0.23 m/s, enough to provide comfort because of the unique design of the inlet feature. However, no air movement was observed in almost all the lower portions of the CPH during winter because of the absence of an inlet feature. There was a significant improvement in weight gain and feed intake of pigs reared in the EPH compared to the CPH (p<0.05). These findings proved that despite the difference in the housing systems, a stable indoor temperature was necessary to minimize the impact of an avoidable and highly fluctuating outdoor temperature. The EPH consistently maintained an effective indoor airspeed irrespective of season; however the CPH had defective and stagnant air at pig nose level during winter. Characteristics of airflow direction and pattern were consistent relative to

  11. Spatio-temporal behavior of brightness temperature in Tel-Aviv and its application to air temperature monitoring.

    PubMed

    Pelta, Ran; Chudnovsky, A Alexandra; Schwartz, Joel

    2016-01-01

    This study applies remote sensing technology to assess and examine the spatial and temporal Brightness Temperature (BT) profile in the city of Tel-Aviv, Israel over the last 30 years using Landsat imagery. The location of warmest and coldest zones are constant over the studied period. Distinct diurnal and temporal BT behavior divide the city into four different segments. As an example of future application, we applied mixed regression models with daily random slopes to correlate Landsat BT data with monitored air temperature (Tair) measurements using 14 images for 1989-2014. Our preliminary results show a good model performance with R(2) = 0.81. Furthermore, based on the model's results, we analyzed the spatial profile of Tair within the study domain for representative days. PMID:26499933

  12. Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

    DOEpatents

    Kuo, L.J.H.; Singh, P.; Ruka, R.J.; Vasilow, T.R.; Bratton, R.J.

    1997-11-11

    A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators. 4 figs.

  13. Computational Fluid Dynamics Analyses on Very High Temperature Reactor Air Ingress

    SciTech Connect

    Chang H Oh; Eung S. Kim; Richard Schultz; David Petti; Hyung S. Kang

    2009-07-01

    A preliminary computational fluid dynamics (CFD) analysis was performed to understand density-gradient-induced stratified flow in a Very High Temperature Reactor (VHTR) air-ingress accident. Various parameters were taken into consideration, including turbulence model, core temperature, initial air mole-fraction, and flow resistance in the core. The gas turbine modular helium reactor (GT-MHR) 600 MWt was selected as the reference reactor and it was simplified to be 2-D geometry in modeling. The core and the lower plenum were assumed to be porous bodies. Following the preliminary CFD results, the analysis of the air-ingress accident has been performed by two different codes: GAMMA code (system analysis code, Oh et al. 2006) and FLUENT CFD code (Fluent 2007). Eventually, the analysis results showed that the actual onset time of natural convection (~160 sec) would be significantly earlier than the previous predictions (~150 hours) calculated based on the molecular diffusion air-ingress mechanism. This leads to the conclusion that the consequences of this accident will be much more serious than previously expected.

  14. Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

    DOEpatents

    Kuo, Lewis J. H.; Singh, Prabhakar; Ruka, Roswell J.; Vasilow, Theodore R.; Bratton, Raymond J.

    1997-01-01

    A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators.

  15. Bias Correction for Assimilation of Retrieved AIRS Profiles of Temperature and Humidity

    NASA Technical Reports Server (NTRS)

    Blakenship, Clay; Zavodsky, Bradley; Blackwell, William

    2014-01-01

    The Atmospheric Infrared Sounder (AIRS) is a hyperspectral radiometer aboard NASA's Aqua satellite designed to measure atmospheric profiles of temperature and humidity. AIRS retrievals are assimilated into the Weather Research and Forecasting (WRF) model over the North Pacific for some cases involving "atmospheric rivers". These events bring a large flux of water vapor to the west coast of North America and often lead to extreme precipitation in the coastal mountain ranges. An advantage of assimilating retrievals rather than radiances is that information in partly cloudy fields of view can be used. Two different Level 2 AIRS retrieval products are compared: the Version 6 AIRS Science Team standard retrievals and a neural net retrieval from MIT. Before assimilation, a bias correction is applied to adjust each layer of retrieved temperature and humidity so the layer mean values agree with a short-term model climatology. WRF runs assimilating each of the products are compared against each other and against a control run with no assimilation. Forecasts are against ERA reanalyses.

  16. Bias Correction for Assimilation of Retrieved AIRS Profiles of Temperature and Humidity

    NASA Technical Reports Server (NTRS)

    Blankenship, Clay; Zavodsky, Brad; Blackwell, William

    2014-01-01

    Atmospheric Infrared Sounder (AIRS) is a hyperspectral radiometer aboard NASA's Aqua satellite designed to measure atmospheric profiles of temperature and humidity. AIRS retrievals are assimilated into the Weather Research and Forecasting (WRF) model over the North Pacific for some cases involving "atmospheric rivers". These events bring a large flux of water vapor to the west coast of North America and often lead to extreme precipitation in the coastal mountain ranges. An advantage of assimilating retrievals rather than radiances is that information in partly cloudy fields of view can be used. Two different Level 2 AIRS retrieval products are compared: the Version 6 AIRS Science Team standard retrievals and a neural net retrieval from MIT. Before assimilation, a bias correction is applied to adjust each layer of retrieved temperature and humidity so the layer mean values agree with a short-term model climatology. WRF runs assimilating each of the products are compared against each other and against a control run with no assimilation. This paper will describe the bias correction technique and results from forecasts evaluated by validation against a Total Precipitable Water (TPW) product from CIRA and against Global Forecast System (GFS) analyses.

  17. Air oxidation behavior of fuel for the High Temperature Engineering Test Reactor (HTTR)

    NASA Astrophysics Data System (ADS)

    Kikuchi, Hironobu; Hayashi, Kimio; Fukuda, Kousaku

    1992-08-01

    The oxidation behavior of the HTTR fuel was studied with respect to the scenario of an air ingress accident which had been assessed in the HTTR safety analysis. The coated fuel particles were heated under a sufficient air flow in the temperature range of 900-1400 C for maximum duration of 600 h (at 1300 C). Failure fractions of the SiC coating layer after the heat treatments remained within the fraction at the fuel production. And the failure behavior of the SiC layer did not depend on such heating conditions as the temperature and the duration in the present experiment. It was confirmed by scanning electron microscopy (SEM), X-ray diffraction, and laser Raman spectroscopy that a thin oxide film was formed on the SiC layer by the heat treatments.

  18. Instructions for observing air temperature, humidity, and direction and force of wind

    USGS Publications Warehouse

    U.S. Geological Survey

    1892-01-01

    Description of instruments.-The temperature and humidity of the air are obtained from the simultaneous observation of a pair of mercurial thermometers termed the dry and the wet bulb. The air temperature is given by the dry-bulb thermometer, and the humidity is obtained from the combined readings of both. The wet-bulb thermometer differs from the dry-bulb thermometer only in having its bulb covered with thin muslin, which is wetted in pure water at each observation.The two thermometers are fastened in a light metal 'or wooden frame. To this frame is to be attached a stout cord for the whirling of the thermometers, which is an essential part of every observation.

  19. Effects of different surfaces on the transport and deposition of ruthenium oxides in high temperature air

    NASA Astrophysics Data System (ADS)

    Vér, N.; Matus, L.; Pintér, A.; Osán, J.; Hózer, Z.

    2012-01-01

    In order to understand the behaviour of ruthenium oxides in the reactor coolant system during an air ingress accident, new tests were performed in the frame of the RUSET (RUthenium Separate Effect Test) experimental program. These aimed to ascertain the effects of different surfaces (quartz, stainless steel (SS), zirconium alloy, alumina, oxidised metal, and surfaces with Mo or Cs deposits) on the transport and decomposition of ruthenium oxides in air stream along the temperature gradient zone (1100-100 °C). The results demonstrated that the heterogeneous phase decomposition of RuO 3 and RuO 4 to RuO 2 is catalysed more efficiently by the quartz surface than by the SS or alumina surfaces. The presence of MoO 3 layers decreased the RuO x precipitation extent on all investigated surfaces. The trapping effect of Cs deposit on Ru in the temperature gradient zone was proved in the case of the SS surface. On the contrary, presence of Cs precipitate on alumina and especially on quartz surfaces was found to decrease their catalytic effect on the decomposition of ruthenium oxides, and thus increased the RuO 4 concentration in the outlet air. Similarly to the effect observed for Cs deposition, the presence of other fission products in the evaporation area (at 1100 °C) decreased the partial pressure of RuO 4 in the outlet air at the SS surface and increased it at quartz and alumina surfaces. When zirconium (E110) cladding material was placed in the temperature gradient zone, no Ru transmittance occurred until the high temperature end of the zirconium tube was completely oxidised. After the intense oxidation of E110, Ru release occurred only in the presence of other fission product species. Pre-oxidation of SS surfaces in steam had no significant effect on the Ru passage.

  20. Composite casting/bonding construction of an air-cooled, high temperature radial turbine wheel

    NASA Technical Reports Server (NTRS)

    Hammer, A. N.; Aigret, G.; Rodgers, C.; Metcalfe, A. G.

    1983-01-01

    A composite casting/bonding technique has been developed for the fabrication of a unique air-cooled, high temperature radial inflow turbine wheel design applicable to auxilliary power units with small rotor diameters and blade entry heights. The 'split blade' manufacturing procedure employed is an alternative to complex internal ceramic coring. Attention is given to both aerothermodynamic and structural design, of which the latter made advantageous use of the exploration of alternative cooling passage configurations through CAD/CAM system software modification.

  1. Regression analysis in modeling of air surface temperature and factors affecting its value in Peninsular Malaysia

    NASA Astrophysics Data System (ADS)

    Rajab, Jasim Mohammed; Jafri, Mohd. Zubir Mat; Lim, Hwee San; Abdullah, Khiruddin

    2012-10-01

    This study encompasses air surface temperature (AST) modeling in the lower atmosphere. Data of four atmosphere pollutant gases (CO, O3, CH4, and H2O) dataset, retrieved from the National Aeronautics and Space Administration Atmospheric Infrared Sounder (AIRS), from 2003 to 2008 was employed to develop a model to predict AST value in the Malaysian peninsula using the multiple regression method. For the entire period, the pollutants were highly correlated (R=0.821) with predicted AST. Comparisons among five stations in 2009 showed close agreement between the predicted AST and the observed AST from AIRS, especially in the southwest monsoon (SWM) season, within 1.3 K, and for in situ data, within 1 to 2 K. The validation results of AST with AST from AIRS showed high correlation coefficient (R=0.845 to 0.918), indicating the model's efficiency and accuracy. Statistical analysis in terms of β showed that H2O (0.565 to 1.746) tended to contribute significantly to high AST values during the northeast monsoon season. Generally, these results clearly indicate the advantage of using the satellite AIRS data and a correlation analysis study to investigate the impact of atmospheric greenhouse gases on AST over the Malaysian peninsula. A model was developed that is capable of retrieving the Malaysian peninsulan AST in all weather conditions, with total uncertainties ranging between 1 and 2 K.

  2. Simultaneous measurements of temperature and density in air flows using UV laser spectroscopy

    NASA Technical Reports Server (NTRS)

    Fletcher, D. G.; Mckenzie, R. L.

    1991-01-01

    The simultaneous measurement of temperature and density using laser-induced fluorescence of oxygen in combination with Q-branch Raman scattering of nitrogen and oxygen is demonstrated in a low-speed air flow. The lowest density and temperature measured in the experiment correspond to the freestream values at Mach 5 in the Ames 3.5-Foot Hypersonic Wind Tunnel for stagnation conditions of 100 atm and 1000 K. The experimental results demonstrate the viability of the optical technique for measurements that support the study of compressible turbulence and the validation of numerical codes in supersonic and hypersonic wind tunnel flows.

  3. Air-coupled ultrasonic tomographic imaging of high-temperature flames.

    PubMed

    Gan, Tat Hean; Hutchins, David A

    2003-09-01

    This paper illustrates the use of air-coupled ultrasonic tomography for the measurement of a high-temperature flame from a natural gas burner, using capacitive ultrasonic transducers in through transmission. This uses a transducer pair, which is scanned in two-dimensional sections at several angles to the jet axis. Travel-time data then is recorded along various paths in counter-propagating directions. By processing the data obtained from propagation times, images have been formed of variations in temperature within the flame, using the tomographic reconstruction approach. PMID:14561039

  4. Integrated LTCC Pressure/Flow/Temperature Multisensor for Compressed Air Diagnostics†

    PubMed Central

    Fournier, Yannick; Maeder, Thomas; Boutinard-Rouelle, Grégoire; Barras, Aurélie; Craquelin, Nicolas; Ryser, Peter

    2010-01-01

    We present a multisensor designed for industrial compressed air diagnostics and combining the measurement of pressure, flow, and temperature, integrated with the corresponding signal conditioning electronics in a single low-temperature co-fired ceramic (LTCC) package. The developed sensor may be soldered onto an integrated electro-fluidic platform by using standard surface mount device (SMD) technology, e.g., as a standard electronic component would be on a printed circuit board, obviating the need for both wires and tubes and thus paving the road towards low-cost integrated electro-fluidic systems. Several performance aspects of this device are presented and discussed, together with electronics design issues. PMID:22163518

  5. High Temperature Tensile Properties of Unidirectional Hi-Nicalon/Celsian Composites In Air

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, John Z.; Bansal, Narottam P.

    2000-01-01

    High temperature tensile properties of unidirectional BN/SiC-coated Hi-Nicalon SiC fiber reinforced celsian matrix composites have been measured from room temperature to 1200 C (2190 F) in air. Young's modulus, the first matrix cracking stress, and the ultimate strength decreased from room temperature to 1200 C (2190 F). The applicability of various micromechanical models, in predicting room temperature values of various mechanical properties for this CMC, has also been investigated. The simple rule of mixtures produced an accurate estimate of the primary composite modulus. The first matrix cracking stress estimated from ACK theory was in good agreement with the experimental value. The modified fiber bundle failure theory of Evans gave a good estimate of the ultimate strength.

  6. Comparative evaluation of air cell and eggshell temperature measurement methodologies used in broiler hatching eggs during late incubation.

    PubMed

    Peebles, E D; Zhai, W; Gerard, P D

    2012-07-01

    The current study was conducted to compare and contrast the uses of 2 devices (temperature transponder or infrared thermometer) and their locations (inner air cell membrane or outer eggshell surface) in Ross × Ross 708 broiler hatching eggs. The air cells of 14 embryonated and 10 nonembryonated eggs were implanted with temperature transponders on d 13.5 of incubation. Likewise, for these same eggs, eggshell surface temperature was detected with the use of transponders and an infrared thermometer. Temperatures were recorded every 12 h between 14.5 and 18 d of incubation, and graphs and corresponding regression values were used to track the temperatures over these time periods. The temperature readings using all methods in embryonated and nonembryonated eggs were positively correlated. In nonembryonated eggs, temperatures in the air cell and on the eggshell surface using transponders were higher than those on the eggshell surface using an infrared thermometer. Mean air cell temperature readings of embryonated eggs using transponders were higher than those of the eggshell, as determined with the use of transponders or an infrared thermometer. Furthermore, the differences in air cell temperature using transponders and eggshell temperature using an infrared thermometer in embryonated eggs increased with embryonic age. These readings confirmed increased embryo heat production during the incubational period examined. It was further concluded that when compared with actual embryo body temperatures determined in previous studies, the use of transponders in the air cells of broiler hatching eggs detected a higher and closer temperature than eggshell surface temperature. It is suggested that the air cell transponders in embryonated eggs circumvented the confounding effects of the thermal barrier properties of the eggshell and the flow of air across its surface. PMID:22700496

  7. The EUSTACE project: combining different components of the observing system to deliver global, daily information on surface air temperature

    NASA Astrophysics Data System (ADS)

    Rayner, Nick

    2016-04-01

    Day-to-day variations in surface air temperature affect society in many ways and are fundamental information for many climate services; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, we must develop an understanding of the relationships between traditional surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. Here we reflect on our experience so far within the Horizon 2020 project EUSTACE of using satellite skin temperature retrievals to help us to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types and developing new statistical models of how surface air temperature varies in a connected way from place to place. We will present plans and progress along this road in the EUSTACE project (2015-June 2018): - providing new, consistent, multi-component estimation of uncertainty in surface skin temperature retrievals from satellites; - identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; - estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; - using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras. Information will also be given on how interested users can become involved.

  8. Temperature retrieval from Rayleigh-Brillouin scattering profiles measured in air.

    PubMed

    Witschas, Benjamin; Gu, Ziyu; Ubachs, Wim

    2014-12-01

    In order to investigate the performance of two different algorithms for retrieving temperature from Rayleigh-Brillouin (RB) line shapes, RB scattering measurements have been performed in air at a wavelength of 403 nm, for a temperature range from 257 K to 330 K, and atmospherically relevant pressures from 871 hPa to 1013 hPa. One algorithm, based on the Tenti S6 line shape model, shows very good accordance with the reference temperature. In particular, the absolute difference is always less than 2 K. A linear correlation yields a slope of 1.01 ± 0.02 and thus clearly demonstrates the reliability of the retrieval procedure. The second algorithm, based on an analytical line shape model, shows larger discrepancies of up to 9.9 K and is thus not useful at its present stage. The possible reasons for these discrepancies and improvements of the analytical model are discussed. The obtained outcomes are additionally verified with previously performed RB measurements in air, at 366 nm, temperatures from 255 K to 338 K and pressures from 643 hPa to 826 hPa [Appl. Opt. 52, 4640 (2013)]. The presented results are of relevance for future lidar studies that might utilize RB scattering for retrieving atmospheric temperature profiles with high accuracy. PMID:25606897

  9. Pattern recognition techniques for visualizing the biotropic waveform of air temperature and pressure

    NASA Astrophysics Data System (ADS)

    Ozheredov, V. A.

    2012-12-01

    It is known that long periods of adverse weather have a negative effect on the human cardiovascular system. A number of studies have set a lower limit of around 5 days for the duration of these periods. However, the specific features of the negative dynamics of the main weather characteristics—air temperature and atmospheric pressure—remained open. To address this problem, the present paper proposes a conjunctive method of the theory of pattern recognition. It is shown that this method approaches a globally optimal (in the sense of recognition errors) Neumann critical region and can be used to solve various problems in heliobiology. To illustrate the efficiency of this method, we show that some quickly relaxing short sequences of temperature and pressure time series (the so-called temperature waves and waves of atmospheric pressure changes) increase the risk of cardiovascular diseases and can lead to serious organic lesions (particularly myocardial infarction). It is established that the temperature waves and waves of atmospheric pressure changes increase the average morbidity rate of myocardial infarction by 90% and 110%, respectively. Atmospheric pressure turned out to be a more biotropic factor than air temperature.

  10. Experimental investigation of ultraviolet laser induced plasma density and temperature evolution in air

    SciTech Connect

    Thiyagarajan, Magesh; Scharer, John

    2008-07-01

    We present measurements and analysis of laser induced plasma neutral densities and temperatures in dry air by focusing 200 mJ, 10 MW high power, 193 nm ultraviolet ArF (argon fluoride) laser radiation to a 30 {mu}m radius spot size. We examine these properties that result from multiphoton and collisional cascade processes for pressures ranging from 40 Torr to 5 atm. A laser shadowgraphy diagnostic technique is used to obtain the plasma electron temperature just after the shock front and this is compared with optical emission spectroscopic measurements of nitrogen rotational and vibrational temperatures. Two-color laser interferometry is employed to measure time resolved spatial electron and neutral density decay in initial local thermodynamic equilibrium (LTE) and non-LTE conditions. The radiating species and thermodynamic characteristics of the plasma are analyzed by means of optical emission spectroscopy (OES) supported by SPECAIR, a special OES program for air constituent plasmas. Core plasma rotational and vibrational temperatures are obtained from the emission spectra from the N{sub 2}C-B(2+) transitions by matching the experimental spectrum results with the SPECAIR simulation results and the results are compared with the electron temperature just behind the shock wave. The plasma density decay measurements are compared with a simplified electron density decay model that illustrates the dominant three-and two-body recombination terms with good correlation.

  11. Experimental investigation of ultraviolet laser induced plasma density and temperature evolution in air

    NASA Astrophysics Data System (ADS)

    Thiyagarajan, Magesh; Scharer, John

    2008-07-01

    We present measurements and analysis of laser induced plasma neutral densities and temperatures in dry air by focusing 200 mJ, 10 MW high power, 193 nm ultraviolet ArF (argon fluoride) laser radiation to a 30 μm radius spot size. We examine these properties that result from multiphoton and collisional cascade processes for pressures ranging from 40 Torr to 5 atm. A laser shadowgraphy diagnostic technique is used to obtain the plasma electron temperature just after the shock front and this is compared with optical emission spectroscopic measurements of nitrogen rotational and vibrational temperatures. Two-color laser interferometry is employed to measure time resolved spatial electron and neutral density decay in initial local thermodynamic equilibrium (LTE) and non-LTE conditions. The radiating species and thermodynamic characteristics of the plasma are analyzed by means of optical emission spectroscopy (OES) supported by SPECAIR, a special OES program for air constituent plasmas. Core plasma rotational and vibrational temperatures are obtained from the emission spectra from the N2C-B(2+) transitions by matching the experimental spectrum results with the SPECAIR simulation results and the results are compared with the electron temperature just behind the shock wave. The plasma density decay measurements are compared with a simplified electron density decay model that illustrates the dominant three-and two-body recombination terms with good correlation.

  12. Bonding to dentin as a function of air-stream temperatures for solvent evaporation.

    PubMed

    Marsiglio, Andréia Aquino; Almeida, Júlio César Franco; Hilgert, Leandro Augusto; D'Alpino, Paulo Henrique Perlatti; Garcia, Fernanda Cristina Pimentel

    2012-01-01

    This study evaluated the influence of solvent evaporation conditions of acid-etching adhesives. The medium dentin of thirty extracted human third molars was exposed and bonded to different types of etch-and-rinse adhesives: 1) Scotchbond Multi-Purpose (SBMP) ; water-based; 2) Adper Single Bond 2 (SB) ; ethanol/water-based, and 3) Prime & Bond 2.1 (PB) ; acetone-based. Solvents were evaporated at air-drying temperatures of 21ºC or 38ºC. Composite buildups were incrementally constructed. After storage in water for 24 h at 37ºC, the specimens were prepared for bond strength testing. Data were analyzed by two-way ANOVA and Tukey's test (5%). SBMP performed better when the solvents were evaporated at a higher temperature (p < 0.05). Higher temperatures did not affect the performance of SB or PB. Bond strength at room temperature was material-dependent, and air-drying temperatures affected bonding of the water-based, acid-etching adhesive. PMID:22641449

  13. Cooling of daytime temperatures in coastal California air basins during 1969-2005: Monthly and extreme value trends

    NASA Astrophysics Data System (ADS)

    Gonzalez, J.; Bornstein, R. D.; Charland, A.; Gonzalez, J.

    2009-12-01

    Analysis of long-term (1969-2005) air temperatures in California (CA) during summer (June-August) previously showed an aggregate CA asymmetric warming, as daily minimum temperatures increased faster than daily maximum values Tmax. The spatial distributions of daily Tmax temperatures in the heavily urbanized South Coast and San Francisco Bay Area air basins were more complex pattern, with cooling at low-elevation coastal-areas and warming at inland areas. Our hypothesis was that this temperature pattern arose from a “reverse-reaction” to greenhouse gas induced global-warming, in that the global warming of inland areas resulted in an increased (cooling) sea breeze activity in coastal areas. These results appeared in the July 2009 issue of the J. of Climate. Extension of this analysis over the entire year now shows that the cooling trend in average Tmax values occurred during most months, with warming trends only during winter months. The largest rate of cooling, however, occurred in June (-0.95 K/decade), indicating that an earlier initiation of sea breeze activity may be the most important cooling factor, relative to increases in its intensity, duration, and/or penetration. Possible beneficial effects of the cooling were discussed (e.g., decreased maximum O3 and human thermal-stress levels), but as these impact would occur during periods of maximum Tmax values, the previous analysis was thus expanded to includes trends in the frequency of high Tmax values, i.e., 85, 90, 95, and 100oF. Results showed that all of these frequencies were decreasing, with rates decreasing with Tmax value (from -0.27 to -0.04 days/year, respectively). While this result is expected, as the frequency of occurrence decreases with Tmax value (from about 50 to about 3 per year, respectively), the percent decrease in frequency showed the opposite results, i.e., it was largest with the highest Tmax value (from -0.57 to -1.57 %/year, respectively). In addition, the rate of decrease of annual

  14. Controlling a rabbet load and air/oil seal temperatures in a turbine

    DOEpatents

    Schmidt, Mark Christopher

    2002-01-01

    During a standard fired shutdown of a turbine, a loaded rabbet joint between the fourth stage wheel and the aft shaft of the machine can become unloaded causing a gap to occur due to a thermal mismatch at the rabbet joint with the bearing blower turned on. An open or unloaded rabbet could cause the parts to move relative to each other and therefore cause the rotor to lose balance. If the bearing blower is turned off during a shutdown, the forward air/oil seal temperature may exceed maximum design practice criterion due to "soak-back." An air/oil seal temperature above the established maximum design limits could cause a bearing fire to occur, with catastrophic consequences to the machine. By controlling the bearing blower according to an optimized blower profile, the rabbet load can be maintained, and the air/oil seal temperature can be maintained below the established limits. A blower profile is determined according to a thermodynamic model of the system.

  15. R&D on Micro-pyrolyzer for Solid Wastes Using High Temperature Steam and Air

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Yoshikawa, Kunio

    An innovative micro-gasification system for solid wastes is proposed in this paper, whose technical feasibility is demonstrated by using rubber chips as a fuel. In this system, a batch-type fixed-bed pyrolyzer combined with a high temperature steam/air reformer is employed. In the present investigation, it is shown that supply of high temperature air into the pyrolyzer significantly increases the heating value of the pyrolysis gas. With the use of high temperature steam/air mixture as an oxidant for reforming, almost complete reforming of the tar components can be done and they are decomposed into CO, H2 and other hydrocarbon gases with reasonable decrease of the heating value of the reformed gas compared with that of the pyrolysis gas. With packing ceramic balls in the reformer, reforming reactions can be accelerated. The experimental results demonstrate that almost soot and tar free clean reformed gas with the heating value of above 1000kcal/Nm3 can be generated from rubber chips.

  16. Picosecond ballistic imaging of diesel injection in high-temperature and high-pressure air

    NASA Astrophysics Data System (ADS)

    Duran, Sean P.; Porter, Jason M.; Parker, Terence E.

    2015-04-01

    The first successful demonstration of picosecond ballistic imaging using a 15-ps-pulse-duration laser in diesel sprays at temperature and pressure is reported. This technique uses an optical Kerr effect shutter constructed from a CS2 liquid cell and a 15-ps pulse at 532 nm. The optical shutter can be adjusted to produce effective imaging pulses between 7 and 16 ps. This technique is used to image the near-orifice region (first 3 mm) of diesel sprays from a high-pressure single-hole fuel injector. Ballistic imaging of dodecane and methyl oleate sprays injected into ambient air and diesel injection at preignition engine-like conditions are reported. Dodecane was injected into air heated to 600 °C and pressurized to 20 atm. The resulting images of the near-orifice region at these conditions reveal dramatic shedding of the liquid near the nozzle, an effect that has been predicted, but to our knowledge never before imaged. These shedding structures have an approximate spatial frequency of 10 mm-1 with lengths from 50 to 200 μm. Several parameters are explored including injection pressure, liquid fuel temperature, air temperature and pressure, and fuel type. Resulting trends are summarized with accompanying images.

  17. Near-infrared Laser-induced Temperature Elevation in Optically-trapped Aqueous Droplets in Air.

    PubMed

    Ishizaka, Shoji; Ma, Jiang; Fujiwara, Terufumi; Yamauchi, Kunihiro; Kitamura, Noboru

    2016-01-01

    Near-infrared laser-induced temperature elevation in single aqueous ammonium sulfate droplets levitated in air were evaluated by means of laser trapping and Raman spectroscopy. Since the vapor pressure in an aqueous solution droplet should be thermodynamically in equilibrium with that of water in air, the equilibrium size of the droplet varies sensitively through evaporation/condensation of water in accordance with the temperature change of the droplet. In this study, we demonstrated that the changes in the size of an optically levitated aqueous ammonium sulfate droplet were induced by irradiation of a 1064-nm laser beam as a heat source under an optical microscope. Temperature elevation in the droplet was evaluated successfully by means of Raman spectroscopy, and the values determined were shown to be in good agreement with those by the theoretical calculations based on the absorption coefficient of water at 1064-nm and the thermal conductivity of air. To the best of our knowledge, this is the first experimental demonstration showing that the absorption coefficient evaluated from changes in the size of optically-trapped aqueous droplets is consistent with that of pure water. PMID:27063715

  18. Simultaneous measurement of temperature and velocity fields in convective air flows

    NASA Astrophysics Data System (ADS)

    Schmeling, Daniel; Bosbach, Johannes; Wagner, Claus

    2014-03-01

    Thermal convective air flows are of great relevance in fundamental studies and technical applications such as heat exchangers or indoor ventilation. Since these kinds of flow are driven by temperature gradients, simultaneous measurements of instantaneous velocity and temperature fields are highly desirable. A possible solution is the combination of particle image velocimetry (PIV) and particle image thermography (PIT) using thermochromic liquid crystals (TLCs) as tracer particles. While combined PIV and PIT is already state of the art for measurements in liquids, this is not yet the case for gas flows. In this study we address the adaptation of the measuring technique to gaseous fluids with respect to the generation of the tracer particles, the particle illumination and the image filtering process. Results of the simultaneous PIV/PIT stemming from application to a fluid system with continuous air exchange are presented. The measurements were conducted in a cuboidal convection sample with air in- and outlet at a Rayleigh number Ra ≈ 9.0 × 107. They prove the feasibility of the method by providing absolute and relative temperature accuracies of σT = 0.19 K and σΔT = 0.06 K, respectively. Further open issues that have to be addressed in order to mature the technique are identified.

  19. Modeling and imaging land-cover influences on air temperature in and near Baltimore, MD

    NASA Astrophysics Data System (ADS)

    Heisler, Gordon M.; Ellis, Alexis; Nowak, David J.; Yesilonis, Ian

    2016-04-01

    Over the course of 1681 hours between May 5 and September 30, 2006, air temperatures measured at the 1.5-m height at seven sites in and near the city of Baltimore, MD were used to empirically model Δ widehat{T} R-p , the difference in air temperature between a site in downtown Baltimore and the six other sites. Variables in the prediction equation included difference between the downtown reference and each of the other sites in upwind tree cover and impervious cover as obtained from 10-m resolution geographic information system (GIS) data. Other predictor variables included an index of atmospheric stability, topographic indices, wind speed, vapor pressure deficit, and antecedent precipitation. The model was used to map predicted hourly Δ widehat{T} R-p across the Baltimore region based on hourly weather data from the airport. Despite the numerous sources of variability in the regression modeling, the method produced reasonable map patterns of Δ widehat{T} R-p that, except for some areas evidently affected by sea breeze from the Chesapeake, closely matched results of mesoscale modeling. Potential applications include predictions of the effect of changing tree cover on air temperature in the area.

  20. A time-series analysis of mortality and air temperature in Greater Beirut.

    PubMed

    El-Zein, Abbas; Tewtel-Salem, Mylene; Nehme, Gebran

    2004-09-01

    The literature on the association between health and weather in the temperate to semi-arid cities of the Eastern Mediterranean is scarce. The quantification of the relationship between temperature and daily mortality can be useful for developing policy interventions such as heat-warning systems. A time-series analysis of total daily mortality and weather data for the city of Beirut was carried out. The study covered the period between 1997 and 1999. Poisson auto-regressive models were constructed, with mean daily temperature and mean daily humidity as explanatory variables. Delayed effects, up to 2 weeks, were accounted for. The regression models were used next to assess the effect of an average increase in temperature on yearly mortality. The association between temperature and mortality was found to be significant. A relatively high minimum-mortality temperature (TMM) of 27.5 degrees C was calculated. A 1 degrees C rise in temperature yielded a 12.3% increase (95% confidence interval: 5.7-19.4%) and 2.9% decrease (95% confidence interval: 2-3.7%) in mortality, above and below TMM, respectively. Lag temperature variables were found to be significant below TMM but not above it. Where the temperature change was less than 0.5 degrees C, annual above-TMM losses were offset by below-TMM gains, within a 95% confidence interval. TMM for Beirut fell within the range usually associated with warm climates. However, the mild below-TMM and steep above-TMM slopes were more typical of cities with temperate to cold climates. Our findings suggest that heat-related mortality at moderately high temperatures can be a significant public health issue in countries with warm climates. Moreover, at the projected climate change over the next 50 years, heat-related losses are unlikely to be offset by cold-related gains. PMID:15325159