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Articles 1 - 17 of 17
Full-Text Articles in Physical Sciences and Mathematics
Methane Observations From The Greenhouse Gases Observing Satellite: Comparison To Ground-Based Tccon Data And Model Calculations, Robert Parker, Hartmut Boesch, Austin Cogan, Annemarie Fraser, Liang Feng, Paul Palmer, Janina Messerschmidt, Nicholas M. Deutscher, David W. Griffith, Justus Notholt, Paul O. Wennberg, Debra Wunch
Methane Observations From The Greenhouse Gases Observing Satellite: Comparison To Ground-Based Tccon Data And Model Calculations, Robert Parker, Hartmut Boesch, Austin Cogan, Annemarie Fraser, Liang Feng, Paul Palmer, Janina Messerschmidt, Nicholas M. Deutscher, David W. Griffith, Justus Notholt, Paul O. Wennberg, Debra Wunch
Faculty of Science - Papers (Archive)
We report new short-wave infrared (SWIR) column retrievals of atmospheric methane (X CH4) from the Japanese Greenhouse Gases Observing SATellite (GOSAT) and compare observed spatial and temporal variations with correlative ground-based measurements from the Total Carbon Column Observing Network (TCCON) and with the global 3-D GEOS-Chem chemistry transport model. GOSAT X CH4 retrievals are compared with daily TCCON observations at six sites between April 2009 and July 2010 (Bialystok, Park Falls, Lamont, Orleans, Darwin and Wollongong). GOSAT reproduces the site-dependent seasonal cycles as observed by TCCON with correlations typically between 0.5 and 0.7 with an estimated single-sounding precision between 0.4-0.8%. …
Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I R. Burling, R J. Yokelson, S K. Akagi, S P. Urbanski, C E. Wold, David W. Griffith, T J. Johnson, J Reardon, D R. Weise
Airborne And Ground-Based Measurements Of The Trace Gases And Particles Emitted By Prescribed Fires In The United States, I R. Burling, R J. Yokelson, S K. Akagi, S P. Urbanski, C E. Wold, David W. Griffith, T J. Johnson, J Reardon, D R. Weise
Faculty of Science - Papers (Archive)
We have measured emission factors for 19 tracegas species and particulate matter (PM2.5) from 14 prescribedfires in chaparral and oak savanna in the southwesternUS, as well as conifer forest understory in the southeasternUS and Sierra Nevada mountains of California. These arelikely the most extensive emission factor field measurementsfor temperate biomass burning to date and the only publishedemission factors for temperate oak savanna fuels. This studyhelps to close the gap in emissions data available for temperatezone fires relative to tropical biomass burning. Wepresent the first field measurements of the biomass burningemissions of glycolaldehyde, a possible precursor for aqueousphase secondary organic aerosol …
Gremo: A Gis-Based Generic Model For Estimating Relative Wave Exposure, Austen Pepper, Marjetta L. Puotinen
Gremo: A Gis-Based Generic Model For Estimating Relative Wave Exposure, Austen Pepper, Marjetta L. Puotinen
Faculty of Science - Papers (Archive)
Wave exposure plays a major role in shaping the ecological structure of nearshore communities, with different community types able to survive and/or thrive when typically exposed to different levels of wave energy. This can be quantified by taking direct field measurements with wave buoys over time and then manipulating the data to derive typical conditions. However, taking these measurements is only feasible for very limited areas due to logistical constraints, and generating them with numerical wave models can also be expensive to run and may require data inputs that are either lacking or are highly uncertain. Instead, the relative differences …
Development Of Non-Antibiotic-Resistant, Chromosomally Based, Constitutive And Inducible Expression Systems For Aroa-Attenuated Salmonella Enterica Serovar Typhimurium, Jake Matic, Tamsin D. Terry, David Van Bockel, Tracy A. Maddocks, David Tinworth, Michael Jennings, Steven P Djordjevic, Mark J. Walker
Development Of Non-Antibiotic-Resistant, Chromosomally Based, Constitutive And Inducible Expression Systems For Aroa-Attenuated Salmonella Enterica Serovar Typhimurium, Jake Matic, Tamsin D. Terry, David Van Bockel, Tracy A. Maddocks, David Tinworth, Michael Jennings, Steven P Djordjevic, Mark J. Walker
Faculty of Science - Papers (Archive)
Live-vaccine delivery systems expressing two model antigens from Mycoplasma hyopneumoniae, F2(P97) (Adh) and NrdF, were constructed using Salmonella enterica serovar Typhimurium aroA (STM-1), and immunogenicity in mice was evaluated. Recombinant plasmid-based expression (PBE) and chromosomally based expression (CBE) systems were constructed. The PBE system was formed by cloning both antigen genes into pJLA507 to create an operon downstream of temperature-inducible promoters. Constitutive CBE was achieved using a promoter-trapping technique whereby the promoterless operon was stably integrated into the chromosome of STM-1, and the expression of antigens was assessed. The chromosomal position of the operon was mapped in four clones. Inducible …
Antimycobacterial Activity Of Cinnamate-Based Esters Of The Triterpenes Betulinic, Oleanolic And Ursolic Acids, Tanud Tanachatchairatana, John B. Bremner, Ratchanaporn Chokchaisiri, Apichart Suksamrarn
Antimycobacterial Activity Of Cinnamate-Based Esters Of The Triterpenes Betulinic, Oleanolic And Ursolic Acids, Tanud Tanachatchairatana, John B. Bremner, Ratchanaporn Chokchaisiri, Apichart Suksamrarn
Faculty of Science - Papers (Archive)
Betulinic acid, oleanolic acid and ursolic acid have been modified at the C-3 position to cinnamate-based esters and in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Ra has been determined. The results indicated that modification of the parent structures of betulinic acid, oleanolic acid and ursolic acid to the p-coumarate and, in the case of the latter two triterpenes, the ferulate ester analogues resulted in high antimycobacterial activity. Structure–activity relationships within the lupane, oleanane and ursane analogues and between these triterpenes are discussed.
Validation Of Ace-Fts V2.2 Measurements Of Hci, Hf, Cci3f And Cci2f2 Using Space-, Balloons- And Ground-Based Instrument Observations, E Mahieu, P Duchatelet, P Demoulin, L Froidevaux, C Randall, Nicholas B. Jones, David W. Griffith, G C. Toon, J-F Blavier, C P Rinsland, R Zander, S Wood, M De Maziere, T Blumenstock, A. Kagawa, J Hannigan, M Coffey, F Hase, D Smale, K Strong, J R. Taylor, Thorsten Warneke, Y Kasai, E Dupuy, V Catoire, C Robert, C Senten, C Tetard, K W. Jucks, C Boone, S Mikuteit, K A. Walker, P Bernath, O Schrems, Y Mebarki, R Nassar, C Servais, Justus Notholt
Validation Of Ace-Fts V2.2 Measurements Of Hci, Hf, Cci3f And Cci2f2 Using Space-, Balloons- And Ground-Based Instrument Observations, E Mahieu, P Duchatelet, P Demoulin, L Froidevaux, C Randall, Nicholas B. Jones, David W. Griffith, G C. Toon, J-F Blavier, C P Rinsland, R Zander, S Wood, M De Maziere, T Blumenstock, A. Kagawa, J Hannigan, M Coffey, F Hase, D Smale, K Strong, J R. Taylor, Thorsten Warneke, Y Kasai, E Dupuy, V Catoire, C Robert, C Senten, C Tetard, K W. Jucks, C Boone, S Mikuteit, K A. Walker, P Bernath, O Schrems, Y Mebarki, R Nassar, C Servais, Justus Notholt
Faculty of Science - Papers (Archive)
Hydrogen chloride (HCl) and hydrogen fluoride (HF) are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl3F) and CFC-12 (CCl2F2), during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) is a space-based instrument that has been performing regular solar occultation measurements of …
Long-Term Tropospheric Formaldehyde Concentrations Deduced From Ground-Based Fourier Transform Solar Infrared Measurements, Nicholas B. Jones, K Riedel, Barbara M. Allen, S. W. Wood, Paul Palmer, K Chance, Justus Notholt
Long-Term Tropospheric Formaldehyde Concentrations Deduced From Ground-Based Fourier Transform Solar Infrared Measurements, Nicholas B. Jones, K Riedel, Barbara M. Allen, S. W. Wood, Paul Palmer, K Chance, Justus Notholt
Faculty of Science - Papers (Archive)
We report a 13-year (1992–2005) dataset of total column measurements of formaldehyde (HCHO) over Lauder, New Zealand, inferred from solar infrared spectra measured using a high-resolution Fourier Transform Spectrometer (FTS). Ambient HCHO concentrations at this rural location are often close to levels typical of remote marine environments (<250 ppt), which are close to the detection limit using standard techniques. Consequently we develop a new method that successfully produces HCHO columns with sufficient sensitivity throughout the whole season. HCHO columns over Lauder have a strong seasonal cycle (±50%), with a mean column of 4.9×1015 molecules cm−2, peaking during summer months. A simple box model of CH4 oxidation reproduces the observed broad-scale seasonal cycle, but significantly underestimates the seasonal peak HCHO ground concentrations during summer. This suggests the existence of an additional significant source of HCHO, possibly isoprene that cannot be explained by oxidation of CH4 alone. The ground-based FTS column data compare well with collocated HCHO column measurements from the Global Ozone Monitoring Experiment (GOME) satellite instrument during the operational period of GOME (1996–2001, r2=0.65, mean bias=10%, n=48).
Ground-Based Solar Absorption Ftir Spectroscopy: Characterization Of Retrievals And First Results From A Novel Optical Design Instrument At A New Ndacc Complementary Station, Aldona Waiacek, J R. Taylor, K Strong, R Saari, T Kertzenmacher, Nicholas B. Jones, David W. Griffith
Ground-Based Solar Absorption Ftir Spectroscopy: Characterization Of Retrievals And First Results From A Novel Optical Design Instrument At A New Ndacc Complementary Station, Aldona Waiacek, J R. Taylor, K Strong, R Saari, T Kertzenmacher, Nicholas B. Jones, David W. Griffith
Faculty of Science - Papers (Archive)
The authors describe the optical design of a high-resolution Fourier Transform Spectrometer (FTS), which serves as the primary instrument at the University of Toronto Atmospheric Observatory (TAO). The FTS is dedicated to ground-based infrared solar absorption atmospheric measurements from Toronto, Ontario, Canada. Instrument performance is discussed in terms of instrumental line shape (ILS) and phase error and modulation efficiency as a function of optical path difference. Typical measurement parameters are presented together with retrieval parameters used to derive total and partial column concentrations of ozone. Retrievals at TAO employ the optimal estimation method (OEM), and some impacts of the necessary …
Co Measurements From The Ace-Fts Satellite Instrument: Data Analysis And Validation Using Ground-Based, Airborne And Spaceborne Observations, C Clerbaux, M George, S Turquety, K A. Walker, Nicholas B. Jones, David W. Griffith, C P Rinsland, E Mahieu, M De Maziere, A. Kagawa, J Hannigan, M Coffey, F Hase, M Hopfner, P Duchatelet, I Kramer, A Strandberg, K Strong, Y Kasai, B Barret, P Ricaud, D Murtagh, E Dupuy, V Catoire, C Robert, C Senten, N J. Livesey, M Luo, M Lopez-Puertas, Ph Medelec, A Pazmino, H Pumphrey, T Borsdorff, P F. Coheur, J P. Cammas, James Drummond, R De Zafra, M Deeter, L Emmons, F Eddounia, J C. Gille, E Le Flochmoen, C Boone, B Funke, M Schneider, G P. Stiller, P Bernath, D P. Edwards
Co Measurements From The Ace-Fts Satellite Instrument: Data Analysis And Validation Using Ground-Based, Airborne And Spaceborne Observations, C Clerbaux, M George, S Turquety, K A. Walker, Nicholas B. Jones, David W. Griffith, C P Rinsland, E Mahieu, M De Maziere, A. Kagawa, J Hannigan, M Coffey, F Hase, M Hopfner, P Duchatelet, I Kramer, A Strandberg, K Strong, Y Kasai, B Barret, P Ricaud, D Murtagh, E Dupuy, V Catoire, C Robert, C Senten, N J. Livesey, M Luo, M Lopez-Puertas, Ph Medelec, A Pazmino, H Pumphrey, T Borsdorff, P F. Coheur, J P. Cammas, James Drummond, R De Zafra, M Deeter, L Emmons, F Eddounia, J C. Gille, E Le Flochmoen, C Boone, B Funke, M Schneider, G P. Stiller, P Bernath, D P. Edwards
Faculty of Science - Papers (Archive)
The Atmospheric Chemistry Experiment (ACE) mission was launched in August 2003 to sound the atmosphere by solar occultation. Carbon monoxide (CO), a good tracer of pollution plumes and atmospheric dynamics, is one of the key species provided by the primary instrument, the ACE-Fourier Transform Spectrometer (ACE-FTS). This instrument performs measurements in both the CO 1-0 and 2-0 ro-vibrational bands, from which vertically resolved CO concentration profiles are retrieved, from the mid-troposphere to the thermosphere. This paper presents an updated description of the ACE-FTS version 2.2 CO data product, along with a comprehensive validation of these profiles using available observations (February …
Annual Variation Of Strato-Mesospheric Carbon Monoxide Measured By Ground-Based Fourier Transform Infrared Spectrometry, Voltaire A. Velazco, S.J. Wood, M Sinnhuber, I Kramer, Nicholas B. Jones, Y Kasai, Justus Notholt, Thorsten Warneke, T Blumenstock, F Hase, F Murcray, O Schrems
Annual Variation Of Strato-Mesospheric Carbon Monoxide Measured By Ground-Based Fourier Transform Infrared Spectrometry, Voltaire A. Velazco, S.J. Wood, M Sinnhuber, I Kramer, Nicholas B. Jones, Y Kasai, Justus Notholt, Thorsten Warneke, T Blumenstock, F Hase, F Murcray, O Schrems
Faculty of Science - Papers (Archive)
We present long-term time-series of strato-mesospheric CO vertical columns measured from stations located in Antarctica, mid-latitudes and the Arctic, covering the period from 19972005. The instrument and the measurement technique allows the separation of tropospheric and strato-mesospheric contributions to the CO column, therefore providing information on the chemistry and dynamics both at low and high altitudes. Data from polar stations show a similar annual variability of strato-mesospheric CO with a strong maximum in late winter and spring. A small enhancement in late summer for some stations, which we call the "summer bulge", can be seen occasionally. Generally, the mid-latitude stations …
Stratomesospheric Co Measured By A Ground-Based Fourier Transform Spectrometer Over Poker Flat, Alaska: Comparisons With Odin/Smr And A 2-D Model, Nicholas B. Jones, Y Kasai, E Dupuy, Y. Murayama, J Urban, B Barret, M Sinnhuber, A. Kagawa, T. Koshiro, P Ricaud, D Murtagh
Stratomesospheric Co Measured By A Ground-Based Fourier Transform Spectrometer Over Poker Flat, Alaska: Comparisons With Odin/Smr And A 2-D Model, Nicholas B. Jones, Y Kasai, E Dupuy, Y. Murayama, J Urban, B Barret, M Sinnhuber, A. Kagawa, T. Koshiro, P Ricaud, D Murtagh
Faculty of Science - Papers (Archive)
The interseasonal variability of stratomesospheric CO is reported from Poker Flat, Alaska, using spectra from a ground-based Fourier Transform Spectrometer (gb-FTS) for the time period from 2000 to 2004. The CO spectra were analyzed using an optimal estimation technique that separates the tropospheric and stratospheric/mesospheric components into partial columns. The distribution of CO in the polar winter is such that the gb-FTS retrieved partial column is weighted to the mesosphere. The gb-FTS data are compared with measurements of partial column CO from the Sub-Millimeter Radiometer on board the Odin satellite and shown to be in very good agreement despite the …
Places Of Reconciliation: Gay, Lesbian And Transgender Place-Based Belongings In A Regional Australian Centre, Gordon R. Waitt, Andrew W. Gorman-Murray
Places Of Reconciliation: Gay, Lesbian And Transgender Place-Based Belongings In A Regional Australian Centre, Gordon R. Waitt, Andrew W. Gorman-Murray
Faculty of Science - Papers (Archive)
Place-based belonging is a key concern of geographical work on sexuality. Marginalised through practices of heterosexism and homophobia, gay men, lesbians and other sexual minorities have a heightened awareness of where they belong – of where they can perform sexual difference. Much research here focuses on place-based belonging in metropolitan centres. There is less consideration of how sexual minorities sustain place-based belonging in regional centres, which are also believed to exhibit higher levels of homophobia. Drawing on in-depth interviews, we examine how sexual minorities generate place-based belonging in Townsville. We argue that place-based belonging be understood as an ongoing relational …
Comparisons Between Sciamachy And Ground-Based Ftir Data For Total Columns Of Co, Ch4, Co2 And N2o, B Dils, M De Maziere, J F. Muller, T Blumenstock, Nicholas B. Jones, David W. Griffith, C P Rinsland, E Mahieu, S Wood, R De Beek, P Demoulin, M Buchwitz, P Duchatelet, C Frankenberg, A Gloudemans, T Kerzenmacher, I Kramer, J Mellqvist, H Shrijver, A Strandberg, D Smale, W Stremme, A G. Straume, R Sussmann, M Van Den Broek, T Wagner, K Strong, Aldona Wiacek, J R. Taylor, Hans Fast, Thorsten Warneke, Richard L. Mittermeier, Justus Notholt, Voltaire A. Velazco
Comparisons Between Sciamachy And Ground-Based Ftir Data For Total Columns Of Co, Ch4, Co2 And N2o, B Dils, M De Maziere, J F. Muller, T Blumenstock, Nicholas B. Jones, David W. Griffith, C P Rinsland, E Mahieu, S Wood, R De Beek, P Demoulin, M Buchwitz, P Duchatelet, C Frankenberg, A Gloudemans, T Kerzenmacher, I Kramer, J Mellqvist, H Shrijver, A Strandberg, D Smale, W Stremme, A G. Straume, R Sussmann, M Van Den Broek, T Wagner, K Strong, Aldona Wiacek, J R. Taylor, Hans Fast, Thorsten Warneke, Richard L. Mittermeier, Justus Notholt, Voltaire A. Velazco
Faculty of Science - Papers (Archive)
Total column amounts of CO, CH4, CO2 and N2O retrieved from SCIAMACHY nadir observations in its near-infrared channels have been compared to data from a ground-based quasi-global network of Fourier-transform infrared (FTIR) spectrometers. The SCIAMACHY data considered here have been produced by three different retrieval algorithms, WFM-DOAS (version 0.5 for CO and CH4 and version 0.4 for CO2 and N2O), IMAP-DOAS (version 1.1 and 0.9 (for CO)) and IMLM (version 6.3) and cover the January to December 2003 time period. Comparisons have been made for individual data, as well as for monthly averages. To maximize the number of reliable coincidences …
First Detection Of Meso-Thermospheric Nitric Oxide (No) By Ground-Based Ftir Solar Absorption Spectroscopy, Aldona Wiacek, Nicholas B. Jones, K Strong, J R. Taylor, Richard L. Mittermeier, Hans Fast
First Detection Of Meso-Thermospheric Nitric Oxide (No) By Ground-Based Ftir Solar Absorption Spectroscopy, Aldona Wiacek, Nicholas B. Jones, K Strong, J R. Taylor, Richard L. Mittermeier, Hans Fast
Faculty of Science - Papers (Archive)
We report the first detection of mesospheric-lower thermospheric (MLT, 50–130 km) NO from ground-based FTIR solar absorption spectra using Lorentz- and Doppler-broadened solar absorption lines in the stratosphere and in the MLT, respectively. We present the first characterization of vertical sensitivity in the FTIR NO retrieval and show that MLT NO partial columns can be retrieved with ~1 independent piece of information using a climatological NO profile extending up to 130 km. The information content analysis also improves the characterization of stratospheric partial column retrievals and is relevant to NO results obtained at other Network for the Detection of Stratospheric …
Atmospheric Carbonyl Sulfide (Ocs) Variation From 1992-2004 By Ground-Based Solar Ftir Spectrometry, Nicholas M. Deutscher, Nicholas B. Jones, David W. Griffith, S. W. Wood, F Murcray
Atmospheric Carbonyl Sulfide (Ocs) Variation From 1992-2004 By Ground-Based Solar Ftir Spectrometry, Nicholas M. Deutscher, Nicholas B. Jones, David W. Griffith, S. W. Wood, F Murcray
Faculty of Science - Papers (Archive)
Analysis of ground-based high-resolution solar FTIR absorption spectra from four sites was performed to determine trends and variability in OCS columns over the period 1992–2004. The sites were Wollongong, Australia (34.45° S, 150.88° E), Lauder, New Zealand (45.0° S, 169.7° E), Arrival Heights, Antarctica (77.8° S, 166.6° E) and Mauna Loa, Hawaii (19.5° N, 155.6° W). Small but significant long-term trends of −0.18±0.02% yr-1 above Hawaii, −0.30±0.12% yr-1 above Wollongong and −0.29±0.14% yr-1 above Lauder, were seen. No significant trend was seen above Arrival Heights. A large peak-to-peak seasonal difference observed in 1996–1997 above Wollongong and reported …
Comparisons Between Sciamachy And Ground-Based Ftir Data For Total Columns Of Co, Ch4, Co2 And N2o, B Dils, M De Maziere, T Blumenstock, M Buchwitz, R De Beek, Nicholas B. Jones, David W. Griffith, P Demoulin, A G Frankenberg, H Duchatelet, Hans Fast
Comparisons Between Sciamachy And Ground-Based Ftir Data For Total Columns Of Co, Ch4, Co2 And N2o, B Dils, M De Maziere, T Blumenstock, M Buchwitz, R De Beek, Nicholas B. Jones, David W. Griffith, P Demoulin, A G Frankenberg, H Duchatelet, Hans Fast
Faculty of Science - Papers (Archive)
Total column amounts of CO, CH4, CO2 and N2O retrieved from SCIAMACHY nadir observations in its near-infrared channels have been compared to data from a ground-based quasi-global network of Fourier-transform infrared (FTIR) spectrometers. The SCIAMACHY data considered 5 here have been produced by three different retrieval algorithms, WFM-DOAS (version 0.4, 0.41 for CH4), IMAP-DOAS (version 0.9) and IMLM (version 5.5) and cover the January to December 2003 time period. Comparisons have been made for individual data, as well as for monthly averages. To maximize the number of reliable coincidences that satisfy the temporal and spatial collocation criteria, the 10 SCIAMACHY …
Photoelectrochemical Cells Based On Inherently Conducting Polymers, Gordon G. Wallace, Chee O. Too, David L. Officer, Paul C Dastoor
Photoelectrochemical Cells Based On Inherently Conducting Polymers, Gordon G. Wallace, Chee O. Too, David L. Officer, Paul C Dastoor
Faculty of Science - Papers (Archive)
This review of photoelectrochemical cells (PECs) based on inherently conducting polymers (ICPs) deals with the mechanisms of operation and the various factors that influence the overall efficiency of PECs. The factors addressed include ICP composition and oxidation state, the use of nanostructured surfaces and interfaces, and the PEC electrolyte and redox mediator.