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Articles 31 - 59 of 59

Full-Text Articles in Social and Behavioral Sciences

Co-Located Column And In Situ Measurements Of Co2 In The Tropics Compared With Model Simulations, T Warneke, A K. Petersen, C Gerbig, A Jordan, C Rodenbeck, M Rothe, Ronald Macatangay, J Norholt, O Schrems Jan 2010

Co-Located Column And In Situ Measurements Of Co2 In The Tropics Compared With Model Simulations, T Warneke, A K. Petersen, C Gerbig, A Jordan, C Rodenbeck, M Rothe, Ronald Macatangay, J Norholt, O Schrems

Faculty of Science - Papers (Archive)

The first ground-based remote sensing measurements of the column averaged volume mixing ratio of CO2 (XCO2) in tropical South America have been obtained at Paramaribo, Suriname (5.8 N, 55.2 W). The remote sensing observations are complemented by surface air-samples collected at the site, analyzed for CO2 and 13CO2. The surface in-situ measurements are strongly influenced by local sources. From the isotopic composition of the air samples the local source component is suggested to be dominated by the terrestrial biosphere. Using 13C from the NOAA/ESRL stations Ascension Is. (ASC), 7.9 S, 14.4W, and Ragged Point (RPB), 13.2 N, 59.4W, the data …


Nanometer-Scale Distance Measurements In Proteins Using Gd3+ Spin Labeling, Alexey Potapov, Hiromasa Yagi, Thomas Huber, Slobodan Jergic, Nicholas E. Dixon, Gottfried Otting, Daniella Goldfarb Jan 2010

Nanometer-Scale Distance Measurements In Proteins Using Gd3+ Spin Labeling, Alexey Potapov, Hiromasa Yagi, Thomas Huber, Slobodan Jergic, Nicholas E. Dixon, Gottfried Otting, Daniella Goldfarb

Faculty of Science - Papers (Archive)

Methods for measuring nanometer-scale distances between specific sites in proteins are essential for analysis of their structure and function. In this work we introduce Gd3+ spin labeling for nanometer-range distance measurements in proteins by high-field pulse electron paramagnetic resonance (EPR). To evaluate the performance of such measurements, we carried out four-pulse double-electron electron resonance (DEER) measurements on two proteins, p75ICD and τC14, labeled at strategically selected sites with either two nitroxides or two Gd3+ spin labels. In analogy to conventional site-directed spin labeling using nitroxides, Gd3+ tags that are derivatives of dipicolinic acid were covalently attached to cysteine thiol groups. …


Train-Borne Measurements Of Tropical Methane Enhancements From Ephemeral Wetlands In Australia, Nicholas M. Deutscher, David W. T Griffith, Clare Paton-Walsh, Rittick Borah Jan 2010

Train-Borne Measurements Of Tropical Methane Enhancements From Ephemeral Wetlands In Australia, Nicholas M. Deutscher, David W. T Griffith, Clare Paton-Walsh, Rittick Borah

Faculty of Science - Papers (Archive)

We report greenhouse gas concentrations measured on a train covering a north-south transect through central Australia from north to south coast. During the monsoonal wet season we found significant enhancements in methane that correlate well with changing area of wetland inundation in Australian tropical savanna regions. We used a meteorological and air pollution model to quantify the ephemeral wetland fluxes necessary to cause the observed enhancements and estimate the constant Australian tropical wetland emissions. Annual Australian tropical ephemeral wetland fluxes are estimated at 0.4 +/- 0.2 Tg CH4, with permanent wetlands contributing a similar amount, 0.5 +/- 0.2 Tg CH4.


Estimated Total Emissions Of Trace Gases From The Canberra Wildfires Of 2003: A New Method Using Satellite Measurements Of Aerosol Optical Depth & The Mozart Chemical Transport Model, Clare Paton-Walsh, L Emmons, Stephen R. Wilson Jan 2010

Estimated Total Emissions Of Trace Gases From The Canberra Wildfires Of 2003: A New Method Using Satellite Measurements Of Aerosol Optical Depth & The Mozart Chemical Transport Model, Clare Paton-Walsh, L Emmons, Stephen R. Wilson

Faculty of Science - Papers (Archive)

In this paper we describe a new method for estimating trace gas emissions from large vegetation fires using satellite measurements of aerosol optical depth (AOD) at 550 nm, combined with an atmospheric chemical transport model. The method uses a threshold value to screen out normal levels of AOD that may be caused by raised dust, sea salt aerosols or diffuse smoke transported from distant fires. Using this method we infer an estimated total emission of 15±5 Tg of carbon monoxide, 0.05±0.02 Tg of hydrogen cyanide, 0.11±0.03 Tg of ammonia, 0.25±0.07 Tg of formaldehyde, 0.03±0.01 of acetylene, 0.10±0.03 Tg of ethylene, …


The Importance Of Transport Model Uncertainties For The Estimation Of Co2 Sources And Sinks Using Satellite Measurements, S Houweling, I Aben, F.-M Breon, F Chevallier, N Deutscher, R Engelen, C Gerbig, D Griffith, K Hungershoefer, R Macatangay, J Marshall, J Notholt, W Peters, S Serrar Jan 2010

The Importance Of Transport Model Uncertainties For The Estimation Of Co2 Sources And Sinks Using Satellite Measurements, S Houweling, I Aben, F.-M Breon, F Chevallier, N Deutscher, R Engelen, C Gerbig, D Griffith, K Hungershoefer, R Macatangay, J Marshall, J Notholt, W Peters, S Serrar

Faculty of Science - Papers (Archive)

This study presents a synthetic model intercomparison to investigate the importance of transport model errors for estimating the sources and sinks of CO2 using satellite measurements. The experiments were designed for testing the potential performance of the proposed CO2 lidar A-SCOPE, but also apply to other space borne missions that monitor total column CO2. The participating transport models IFS, LMDZ, TM3, and TM5 were run in forward and inverse mode using common CO2 fluxes and initial concentrations. Simulated column averaged CO2 (xCO 2) mixing ratios vary between the models by σCombining double low line0.5 ppm over the continents and σCombining …


Validation Of Five Years (2003-2007) Of Sciamachy Co Total Column Measurements Using Ground-Based Spectrometer Observations, A T. J De Laat, A M. S Gloudemans, H Schrijver, I Aben, Y Nagahama, K Suzuki, E Mahieu, N B. Jones, Clare Paton-Walsh, N M. Deutscher, D W. T Griffith, M De Maziere, R L. Mittermeier, H Fast, J Notholt, M Palm, T Hawat, T Blumenstock, F Hase, M Schneider, C Rinsland, A V. Dzhola, E I. Grechko, A M. Poberovskii, M V. Makarova, J Mellqvist, A Strandberg, R Sussmann, T Borsdorff, M Rettinger Jan 2010

Validation Of Five Years (2003-2007) Of Sciamachy Co Total Column Measurements Using Ground-Based Spectrometer Observations, A T. J De Laat, A M. S Gloudemans, H Schrijver, I Aben, Y Nagahama, K Suzuki, E Mahieu, N B. Jones, Clare Paton-Walsh, N M. Deutscher, D W. T Griffith, M De Maziere, R L. Mittermeier, H Fast, J Notholt, M Palm, T Hawat, T Blumenstock, F Hase, M Schneider, C Rinsland, A V. Dzhola, E I. Grechko, A M. Poberovskii, M V. Makarova, J Mellqvist, A Strandberg, R Sussmann, T Borsdorff, M Rettinger

Faculty of Science - Papers (Archive)

Abstract. This paper presents a validation study of SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) carbon monoxide (CO) total column measurements from the Iterative Maximum Likelihood Method (IMLM) algorithm using ground-based spectrometer observations from twenty surface stations for the five year time period of 2003–2007. Overall we find a good agreement between SCIAMACHY and ground-based observations for both mean values as well as seasonal variations. For high-latitude Northern Hemisphere stations absolute differences between SCIAMACHY and ground-based measurements are close to or fall within the SCIAMACHY CO 2 precision of 0.2×1018 molecules/cm2 (10%) indicating that SCIAMACHY can observe CO accurately …


Laboratory Measurements Of Trace Gas Emissions From Biomass Burning Of Fuel Types From The Southeastern And Southwestern United States, I R. Burling, R J. Yokelson, David W. Griffith, T J. Johnson, P Veres, J.M. Roberts, Carsten Warneke, S P. Urbanski, J Reardon, D R. Weise, W M Hao, Joost A. De Gouw Jan 2010

Laboratory Measurements Of Trace Gas Emissions From Biomass Burning Of Fuel Types From The Southeastern And Southwestern United States, I R. Burling, R J. Yokelson, David W. Griffith, T J. Johnson, P Veres, J.M. Roberts, Carsten Warneke, S P. Urbanski, J Reardon, D R. Weise, W M Hao, Joost A. De Gouw

Faculty of Science - Papers (Archive)

Vegetation commonly managed by prescribed burning was collected from five southeastern and southwestern US military bases and burned under controlled conditions at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The smoke emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP-FTIR) spectrometer for measurement of gas-phase species. The OP-FTIR detected and quantified 19 gas-phase species in these fires: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. Emission factors for these species are presented for each vegetation type burned. …


Validation Of Ozone Measurements From The Atmospheric Chemistry Experiment (Ace), Nicholas B. Jones, David W. Griffith, M Wolff, E Mahieu, G Bodeker, I Boyd, M De Maziere, P Demoulin, T Blumenstock, Y. Murayama, A. Kagawa, J Jin, Christopher Mcelroy, J Hannigan, M Coffey, M Hopfner, H W. Fischer, T Kerzenmacher, I Kramer, J Mellqvist, R Sussmann, K Strong, J R. Taylor, K Mizutani, Y Kasai, J Urban, D Murtagh, E Dupuy, V Catoire, S Chabrillat, P Baron, C Brogniez, G L. Manney, C Piccolo, C Randall, C Robert, C Senten, C Tetard, N J. Livesey, A Kleinbohl, S Godin-Beekmann, T Borsdorff, James Drummond, C De Clercq, J C. Lambert, U Cortesi, K W. Jucks, C Boone, H Oelhaf, M Schneider, T Steck, K A. Walker, P Bernath, T Von Clarmann, R Hughes, C Vigouroux, J Kuttippurath, A Bracher, J Mcconnell, C Mclinden, H Kullmann, L Froidevaux, J Dodion, F Vanhellemont, J P. Burrows, J Kar, F Goutail, D G. Dufour, J M. Zawodny, F Nichitiu, J-P Pommereau, C Nowlan, D Fussen, J Zou, A R Klekociuk, G Forbes, H Bovensmann, R M Bevilacqua, C Haley, S Ceccherini, S D Mcleod, P Gerard, R Skelton, B Firanski, A E Bourassa, D A Degenstein, J Davies, T Christensen, J Granville, A Parrish, C Roth, J W. Waters, C Von Savigny, A Standberg, M Mchugh, A M. Thompson, E J Llewellyn, P Von Der Gathen, M B. Tully, J C. Witte, C Roth, B T. Marshall, K B. Strawbridge, E Kyrola, M P. Mccormick, D P J Swart, N D Lloyd, D W. Tarasick, S V. Petelina, L W. Thomason, A Jones, I S. Mcdermid Jan 2009

Validation Of Ozone Measurements From The Atmospheric Chemistry Experiment (Ace), Nicholas B. Jones, David W. Griffith, M Wolff, E Mahieu, G Bodeker, I Boyd, M De Maziere, P Demoulin, T Blumenstock, Y. Murayama, A. Kagawa, J Jin, Christopher Mcelroy, J Hannigan, M Coffey, M Hopfner, H W. Fischer, T Kerzenmacher, I Kramer, J Mellqvist, R Sussmann, K Strong, J R. Taylor, K Mizutani, Y Kasai, J Urban, D Murtagh, E Dupuy, V Catoire, S Chabrillat, P Baron, C Brogniez, G L. Manney, C Piccolo, C Randall, C Robert, C Senten, C Tetard, N J. Livesey, A Kleinbohl, S Godin-Beekmann, T Borsdorff, James Drummond, C De Clercq, J C. Lambert, U Cortesi, K W. Jucks, C Boone, H Oelhaf, M Schneider, T Steck, K A. Walker, P Bernath, T Von Clarmann, R Hughes, C Vigouroux, J Kuttippurath, A Bracher, J Mcconnell, C Mclinden, H Kullmann, L Froidevaux, J Dodion, F Vanhellemont, J P. Burrows, J Kar, F Goutail, D G. Dufour, J M. Zawodny, F Nichitiu, J-P Pommereau, C Nowlan, D Fussen, J Zou, A R Klekociuk, G Forbes, H Bovensmann, R M Bevilacqua, C Haley, S Ceccherini, S D Mcleod, P Gerard, R Skelton, B Firanski, A E Bourassa, D A Degenstein, J Davies, T Christensen, J Granville, A Parrish, C Roth, J W. Waters, C Von Savigny, A Standberg, M Mchugh, A M. Thompson, E J Llewellyn, P Von Der Gathen, M B. Tully, J C. Witte, C Roth, B T. Marshall, K B. Strawbridge, E Kyrola, M P. Mccormick, D P J Swart, N D Lloyd, D W. Tarasick, S V. Petelina, L W. Thomason, A Jones, I S. Mcdermid

Faculty of Science - Papers (Archive)

This paper presents extensive bias determination analyses of ozone observations from the Atmospheric Chemistry Experiment (ACE) satellite instruments: the ACE Fourier Transform Spectrometer (ACE-FTS) and the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (ACE-MAESTRO) instrument. Here we compare the latest ozone data products from ACE-FTS and ACE-MAESTRO with coincident observations from nearly 20 satellite-borne, airborne, balloonborne and ground-based instruments, by analysing volume mixing ratio profiles and partial column densities. The ACEFTS version 2.2 Ozone Update product reports more ozone than most correlative measurements from the upper troposphere to the lower mesosphere. At altitude levels from …


Exploring Co Pollution Episodes Observed At Rishiri Island By Chemical Weather Simulations And Airs Satellite Measurements: Long-Range Transport Of Burning Plumes And Implications For Emissions Inventories, Hiroshi Tanimoto, Keiichi Sato, Tim Butler, Mark G. Lawrence, Jenny A. Fisher, M Kopacz, Robert M. Yantosca, Yugo Kanaya, Shungo Kato, Tomoaki Okuda, Shigeru Tanaka, Jiye Zeng Jan 2009

Exploring Co Pollution Episodes Observed At Rishiri Island By Chemical Weather Simulations And Airs Satellite Measurements: Long-Range Transport Of Burning Plumes And Implications For Emissions Inventories, Hiroshi Tanimoto, Keiichi Sato, Tim Butler, Mark G. Lawrence, Jenny A. Fisher, M Kopacz, Robert M. Yantosca, Yugo Kanaya, Shungo Kato, Tomoaki Okuda, Shigeru Tanaka, Jiye Zeng

Faculty of Science - Papers (Archive)

The summer of 2003 was an active forest fire season in Siberia. Several events of elevated carbon monoxide (CO) were observed at Rishiri Island in northern Japan during an intensive field campaign in September 2003. A simulation with a global chemistry-transport model is able to reproduce the general features of the baseline levels and variability in the observed CO, and a source attribution for CO in the model suggests that the contribution from North Asia dominated, accounting for approximately 50% on average, with contributions of 7% from North America and 8% from Europe and 30% from oxidation of hydrocarbons. With …


Long-Term Tropospheric Formaldehyde Concentrations Deduced From Ground-Based Fourier Transform Solar Infrared Measurements, N B. Jones, K Riedel, W Allan, S Wood, P I. Palmer, K Chance, J Notholt Jan 2009

Long-Term Tropospheric Formaldehyde Concentrations Deduced From Ground-Based Fourier Transform Solar Infrared Measurements, N B. Jones, K Riedel, W Allan, S Wood, P I. Palmer, K Chance, J 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).


Global Airs And Mopitt Co Measurements: Validation, Comparison, And Links To Biomass Burning Variations And Carbon Cycle, Leonid N. Yurganov, W. Wallace Mcmillan, Anatoly V. Dzhola, Evgeny I. Grechko, Nicholas B. Jones, Guido R. Van Der Werf Jan 2008

Global Airs And Mopitt Co Measurements: Validation, Comparison, And Links To Biomass Burning Variations And Carbon Cycle, Leonid N. Yurganov, W. Wallace Mcmillan, Anatoly V. Dzhola, Evgeny I. Grechko, Nicholas B. Jones, Guido R. Van Der Werf

Faculty of Science - Papers (Archive)

New results of CO global total column measurements using the Atmospheric Infrared Sounder (AIRS) aboard the Aqua satellite in comparison with Measurements of Pollution in the Troposphere (MOPITT) sensor aboard the Terra satellite are presented. Both data sets are validated using ground-based total column measurements in Russia and Australia. A quality parameter based on the Profile Percent A Priori values from the standard MOPITT product is introduced. AIRS data (version 4) for biomass burning events are in agreement or lower than both MOPITT and ground measurements, but CO bursts can be seen by AIRS in most cases. For the cases …


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 Jan 2008

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 …


Validation Of Ace-Fts N2o Measurements, K Strong, M Wolff, T Kerzenmacher, K A. Walker, Nicholas B. Jones, David W. Griffith, E Mahieu, S Wood, M De Maziere, P Demoulin, T Blumenstock, J Jin, J Hannigan, M Coffey, M Hopfner, P Duchatelet, J Mellqvist, A Strandberg, J R. Taylor, Thorsten Warneke, J Urban, D Murtagh, E Dupuy, V Catoire, C Piccolo, C Robert, C Senten, C Tetard, K W. Jucks, C Boone, N Glatthor, M Schneider, S Mikuteit, G P. Stiller, P Bernath, O Schrems, H Kuellmann, P Raspollini, A Lambert, J Mcconnell, J Kittippurath, K Semeniuk, M Toohey, M Ridolfi, Justus Notholt Jan 2008

Validation Of Ace-Fts N2o Measurements, K Strong, M Wolff, T Kerzenmacher, K A. Walker, Nicholas B. Jones, David W. Griffith, E Mahieu, S Wood, M De Maziere, P Demoulin, T Blumenstock, J Jin, J Hannigan, M Coffey, M Hopfner, P Duchatelet, J Mellqvist, A Strandberg, J R. Taylor, Thorsten Warneke, J Urban, D Murtagh, E Dupuy, V Catoire, C Piccolo, C Robert, C Senten, C Tetard, K W. Jucks, C Boone, N Glatthor, M Schneider, S Mikuteit, G P. Stiller, P Bernath, O Schrems, H Kuellmann, P Raspollini, A Lambert, J Mcconnell, J Kittippurath, K Semeniuk, M Toohey, M Ridolfi, Justus Notholt

Faculty of Science - Papers (Archive)

The Atmospheric Chemistry Experiment (ACE), also known as SCISAT, was launched on 12 August 2003,carrying two instruments that measure vertical profiles of atmospheric constituents using the solar occultation technique.One of these instruments, the ACE Fourier Transform Spectrometer (ACE-FTS), is measuring volume mixing ratio profiles of nitrous oxide (N2O) from the upper troposphere to the lower mesosphere. In this study, the quality of the ACE-FTS version 2.2 N2O data is assessed rough comparisons with coincident measurements made by other satellite, balloon-borne, aircraft, and ground-based instruments.These consist of vertical profile comparisons with the SMR, MLS, and MIPAS satellite instruments, multiple aircraft flights …


Validation Of Mipas Clono2 Measurements, M Hopfner, T Von Clarmann, Nicholas B. Jones, David W. Griffith, G C. Toon, E Mahieu, R Zander, S Wood, T Blumenstock, J Hannigan, M Coffey, F Hase, H W. Fischer, J Mellqvist, A Strandberg, Thorsten Warneke, C E. Blom, C Piesch, K W. Jucks, K Chance, W Kouker, T Reddmann, C Boone, H Oelhaf, C Keim, N Glatthor, M Kiefer, S Kellmann, R Ruhnke, A Linden, G Y. Liu, B Funke, M Milz, M Schneider, G Wetzel, T Steck, A Kleinert, S Mikuteit, G P. Stiller, U Grabowski, K A. Walker, P Bernath, F Friedl-Vallon, Justus Notholt Jan 2007

Validation Of Mipas Clono2 Measurements, M Hopfner, T Von Clarmann, Nicholas B. Jones, David W. Griffith, G C. Toon, E Mahieu, R Zander, S Wood, T Blumenstock, J Hannigan, M Coffey, F Hase, H W. Fischer, J Mellqvist, A Strandberg, Thorsten Warneke, C E. Blom, C Piesch, K W. Jucks, K Chance, W Kouker, T Reddmann, C Boone, H Oelhaf, C Keim, N Glatthor, M Kiefer, S Kellmann, R Ruhnke, A Linden, G Y. Liu, B Funke, M Milz, M Schneider, G Wetzel, T Steck, A Kleinert, S Mikuteit, G P. Stiller, U Grabowski, K A. Walker, P Bernath, F Friedl-Vallon, Justus Notholt

Faculty of Science - Papers (Archive)

Altitude profiles of ClONO2 retrieved with the IMK (Institut fur Meteorologie und Klimaforschung) science-oriented data processor from MIPAS/Envisat (Michelson Interferometer for Passive Atmospheric Sounding on Envisat) mid-infrared limb emission measurements between July 2002 and March 2004 have been validated by comparison with balloon-borne (Mark IV, FIRS2, MIPASB), airborne (MIPAS-STR), ground-based (Spitsbergen, Thule, Kiruna, Harestua, Jungfraujoch, Izana, Wollongong, Lauder), and spaceborne (ACE-FTS) observations. With few exceptions we found very good agreement between these instruments and MIPAS with no evidence for any bias in most cases and altitude regions. For balloon-borne measurements typical absolute mean differences are below 0.05 ppbv over the …


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 Jan 2007

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 …


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 Jan 2007

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).


The Tropical Forest And Fire Emissions Experiment: Overview And Airborne Fire Emission Factor Measurements, Robert Yokelson, Thomas Karl, P Artaxo, D Blake, Theodore Christian, David W. Griffith, A Guenther, W M Hao Jan 2007

The Tropical Forest And Fire Emissions Experiment: Overview And Airborne Fire Emission Factor Measurements, Robert Yokelson, Thomas Karl, P Artaxo, D Blake, Theodore Christian, David W. Griffith, A Guenther, W M Hao

Faculty of Science - Papers (Archive)

The Tropical Forest and Fire Emissions Experiment (TROFFEE) used laboratory measurements followed by airborne and ground based field campaigns during the 2004 Amazon dry season to quantify the emissions from pristine tropical forest and several plantations as well as the emissions, fuel consumption, and fire ecology of tropical deforestation fires. The airborne campaign used an Embraer 110B aircraft outfitted with whole air sampling in canisters, mass-calibrated nephelometry, ozone by UV absorbance, Fourier transform infrared spectroscopy (FTIR), and proton-transfer mass spectrometry (PTR-MS) to measure PM10, O3, CO2, CO, NO, NO2, HONO, HCN, NH3, OCS, DMS, CH4, and up to 48 non-methane …


Stereoscopic Visualization And Editing Of Automatic Abdominal Aortic Aneurysms (Aaa) Measurements For Stent Graft Planning, Luping Zhou, Yaping Wang, Lin-Chia Goh, Ralf A. Kockro, Luis Serra Jan 2006

Stereoscopic Visualization And Editing Of Automatic Abdominal Aortic Aneurysms (Aaa) Measurements For Stent Graft Planning, Luping Zhou, Yaping Wang, Lin-Chia Goh, Ralf A. Kockro, Luis Serra

Faculty of Engineering and Information Sciences - Papers: Part A

For stent graft selection in the treatment of abdominal aortic aneurysms (AAA) anatomic considerations are important. They determine GO/NO-GO of the treatment and help customize the stent. Current systems for AAA stent insertion planning based on pre-operative CT and MR of the patient do not provide an intuitive interface to view the resulting measurements against the pre-operative CT/MR. Subsequent modifications of the measurements are frequent when automatic algorithms are inaccurate. However, 3D editing is difficult to achieve because of the limitations of monoscopic displays and 2D interface. In this paper, we present a system for automatic AAA measurement and interactive …


Shipborne Solar Absorption Measurements Of Co2, Ch4, N2o And Co And Comparison With Sciamachy Wfm-Doas Retrievals, T Warneke, R De Beek, M Buchwitz, J Notholt, A Schulz, Voltaire A. Velazco, O Schrems Jan 2005

Shipborne Solar Absorption Measurements Of Co2, Ch4, N2o And Co And Comparison With Sciamachy Wfm-Doas Retrievals, T Warneke, R De Beek, M Buchwitz, J Notholt, A Schulz, Voltaire A. Velazco, O Schrems

Faculty of Science - Papers (Archive)

CO, CH4, N2O and CO2 were retrieved from high resolution solar absorption spectra obtained during a ship cruise from Capetown to Bremerhaven in January/February 2003 by Fourier Transform Infrared (FTIR) spectroscopy. Precisions of better than 0.5% for the column averaged volume mixing ratios (VMR) of CH4 and CO2 are achieved using of O2 as a reference gas. Shipborne FTIR-measurements of CO and data from SCIAMACHY/ENVISAT retrieved by the Weighting Function Modified Differential Optical Absorption Spectroscopy (WFM-DOAS) retrieval algorithm show qualitatively the same latitudinal variations. WFMDOAS data of CH4, N2O and CO2 measured over sea exhibit a great spread. The spread …


Quantitative Force Measurements In Liquid Using Frequency Modulation Atomic Force Microscopy, Suzi P. Jarvis, S. Akita, Takayuki Uchihashi, John E. Sader, Y. Nakayama, Michael J. Higgins, S Yasuda Jan 2004

Quantitative Force Measurements In Liquid Using Frequency Modulation Atomic Force Microscopy, Suzi P. Jarvis, S. Akita, Takayuki Uchihashi, John E. Sader, Y. Nakayama, Michael J. Higgins, S Yasuda

Faculty of Science - Papers (Archive)

The measurement of short-range forces with the atomic force microscope (AFM) typically requires implementation of dynamic techniques to maintain sensitivity and stability. While frequency modulation atomic force microscopy (FM-AFM) is used widely for high-resolution imaging and quantitative force measurements in vacuum, quantitative force measurements using FM-AFM in liquids have proven elusive. Here we demonstrate that the formalism derived for operation in vacuum can also be used in liquids, provided certain modifications are implemented. To facilitate comparison with previous measurements taken using surface forces apparatus, we choose a model system (octamethylcyclotetrasiloxane) that is known to exhibit short-ranged structural ordering when confined …


Intercomparison Of Ndsc Ground-Based Solar Ftir Measurements Of Atmospheric Gases At Lauder, New Zealand, D W. T Griffith, Nicholas Jones, B Mcnamara, Clare Paton-Walsh, W. R. Bell, Cirilo Bernado Jan 2003

Intercomparison Of Ndsc Ground-Based Solar Ftir Measurements Of Atmospheric Gases At Lauder, New Zealand, D W. T Griffith, Nicholas Jones, B Mcnamara, Clare Paton-Walsh, W. R. Bell, Cirilo Bernado

Faculty of Science, Medicine and Health - Papers: part A

A formal intercomparison of atmospheric total column measurements of N2O, N2, CH4, O3, HCl, HNO3, and HF by two ground-based solar Fourier transform infrared (FTIR) spectrometers conducted as part of the Network for the Detection of Stratospheric Change (NDSC) instrument certification procedure at Lauder, New Zealand, is presented. The two instruments were nominally very similar, collocated, and collected data at the same times. Collected spectra were analyzed independently by the individual operators in a blind-phase intercomparison, then reanalyzed by a single operator using identical analysis methods to eliminate any potential …


Relative Bias In Diet History Measurements: A Quality Control Technique For Dietary Intervention Trials, Gina S. Martin, Linda C. Tapsell, Marijka Batterham, Kenneth G. Russell Jan 2002

Relative Bias In Diet History Measurements: A Quality Control Technique For Dietary Intervention Trials, Gina S. Martin, Linda C. Tapsell, Marijka Batterham, Kenneth G. Russell

Faculty of Health and Behavioural Sciences - Papers (Archive)

Objective: Investigation of relative bias in diet history measurement during dietary intervention trials.

Design: Retrospective analysis of human dietary data from two randomised controlled trials examining modified fat diets in the prevention and treatment of type II diabetes mellitus.

Setting: Wollongong, Australia.

Subjects: Thirty-five overweight, otherwise healthy subjects in trial 1 and 56 subjects with diabetes in trial 2.

Interventions: Diet history interviews and three-day weighed food records administered at one-month intervals in trial 1 and three-month intervals in trial 2.

Results: In a cross-sectional bias analysis, graphs of the association between bias and mean dietary intake showed that bias …


Validation Of Version 5.20 Ilas Hno3, Ch4, N2o, O3, And No2 Using Ground-Based Measurements At Arrival Heights And Kiruna, S W. Wood, G E. Bodeker, I S. Boyd, Nicholas Jones, B J. Connor, P V. Johnston, W A. Matthews, S E. Nichol, F J. Murcray, H Nakajima, Y Sasano Jan 2002

Validation Of Version 5.20 Ilas Hno3, Ch4, N2o, O3, And No2 Using Ground-Based Measurements At Arrival Heights And Kiruna, S W. Wood, G E. Bodeker, I S. Boyd, Nicholas Jones, B J. Connor, P V. Johnston, W A. Matthews, S E. Nichol, F J. Murcray, H Nakajima, Y Sasano

Faculty of Science, Medicine and Health - Papers: part A

Ground-based measurements of O3 and NO2 columns at Kiruna (68°N) and Arrival Heights (78°S) were used to validate stratospheric profile measurements of the same species by the satellite-based Improved Limb Atmospheric Spectrometer (ILAS) flown between November 1996 and June 1997. In addition, measurements of HNO3, CH4, and N2O made at Arrival Heights are compared with measurements of these species by ILAS. Even though there were no temporal coincidences in the latter comparison, the ground-based data provide a climatological context for the ILAS measurements. ILAS profiles measured within 10° of longitude and 2° …


Multiyear Infrared Solar Spectroscopic Measurements Of Hcn, Co, C2h6, And C2h2 Tropospheric Columns Above Lauder, New Zealand (45 S Latitude), C P. Rinsland, Nicholas Jones, Brian J. Connor, Stephen W. Wood, Aaron Goldman, Thomas M. Stephen, Frank J. Murcray, Linda S. Chiou, Rodolphe Zander, Emmanuel Mahieu Jan 2002

Multiyear Infrared Solar Spectroscopic Measurements Of Hcn, Co, C2h6, And C2h2 Tropospheric Columns Above Lauder, New Zealand (45 S Latitude), C P. Rinsland, Nicholas Jones, Brian J. Connor, Stephen W. Wood, Aaron Goldman, Thomas M. Stephen, Frank J. Murcray, Linda S. Chiou, Rodolphe Zander, Emmanuel Mahieu

Faculty of Science, Medicine and Health - Papers: part A

Near-simultaneous, 0.0035 or 0.007 cm−1 resolution infrared solar absorption spectra of tropospheric HCN, C2H2, CO, and C2H6 have been recorded from the Network for the Detection of Stratospheric Change station in Lauder, New Zealand (45.04°S, 169.68°E, 0.37 km altitude). All four molecules were measured on over 350 days with HCN and C2H2 reported for the first time based on a new analysis procedure that significantly increases the effective signal-to-noise of weak tropospheric absorption features in the measured spectra. The CO measurements extend by 2.5 years a database of measurements …


Ground-Based Infrared Spectroscopic Measurements Of Carbonyl Sulfide: Free Tropospheric Trends From A 24-Year Time Series Of Solar Absorption Measurements, C P. Rinsland, A Goldman, E Mahieu, R Zander, J Notholt, Nicholas Jones, D W. T Griffith, T M. Stephen, L S. Chiou Jan 2002

Ground-Based Infrared Spectroscopic Measurements Of Carbonyl Sulfide: Free Tropospheric Trends From A 24-Year Time Series Of Solar Absorption Measurements, C P. Rinsland, A Goldman, E Mahieu, R Zander, J Notholt, Nicholas Jones, D W. T Griffith, T M. Stephen, L S. Chiou

Faculty of Science, Medicine and Health - Papers: part A

Solar absorption spectra recorded over a 24-year time span have been analyzed to retrieve average free tropospheric mixing ratios of carbonyl sulfide (OCS). The measurements were recorded with the Fourier transform spectrometer located in the U.S. National Solar Observatory McMath solar telescope facility on Kitt Peak (altitude 2.09 km, lat. 31.9°N, long. 111.6°W), southwest of Tucson, Arizona, and were obtained on 167 days between May 1978 and February 2002, typically at 0.01-cm−1 spectral resolution. A best fit to the time series shows an average mixing ratio of 566 pptv (1 pptv = 10−12 per unit volume) between 2.09 …


Mesospheric Temperatures From Observations Of The Hydroxyl (6-2) Emission Above Davis, Antarctica: A Comparison Of Rotational And Doppler Measurements, J L. Innis, Frances Phillips, G B. Burns, P A. Greet, W J R French, P L. Dyson Jan 2001

Mesospheric Temperatures From Observations Of The Hydroxyl (6-2) Emission Above Davis, Antarctica: A Comparison Of Rotational And Doppler Measurements, J L. Innis, Frances Phillips, G B. Burns, P A. Greet, W J R French, P L. Dyson

Faculty of Science, Medicine and Health - Papers: part A

We present observations of the hydroxyl (6–2) airglow lines from ~ 87 km altitude obtained at Davis station, Antarctica, in the austral winter of 1999. Nine nights of observations were made of the P-branch near λ840 nm with a Czerny-Turner scanning spectrometer (CTS); at the same time, high-resolution Fabry-Perot Spectrometer (FPS) spectra were collected of the Q1(1) doublet at λ834 nm. Rotational temperatures were determined from the CTS observations, while Doppler temperatures were derived from the line-widths of the FPS Q1(1) spectra. Absolute temperatures determined by these methods are uncertain by ~ 2 and ~ 20 …


Ground-Based Measurements Of Tropospheric Co, C2h6, And Hcn From Australia At 34 S Latitude During 1997-1998, Curtis P. Rinsland, Arndt Meier, D W T Griffith, Linda S. Chiou Jan 2001

Ground-Based Measurements Of Tropospheric Co, C2h6, And Hcn From Australia At 34 S Latitude During 1997-1998, Curtis P. Rinsland, Arndt Meier, D W T Griffith, Linda S. Chiou

Faculty of Science, Medicine and Health - Papers: part A

High spectral resolution (0.004 cm−1) infrared solar absorption measurements of CO, C2H6, and HCN have been recorded with the Fourier transform spectrometer located at the Network for the Detection of Stratospheric Change complementary station at the University of Wollongong, Australia (34.45°S, 150.88°E, 30 m above sea level). The time series covers March 1997 to February 1998. Profile retrievals with maximum sensitivity in the upper troposphere show distinct seasonal cycles for all three molecules with maxima during October-December 1997. Best fits to the time series of daily averages yield peak 0.03–14 km columns (molecules cm …


Far-Infrared Measurements Of Cyclotron Resonance And Impurity Transitions In Bulk N-Gaas In Pulsed Magnetic Fields, R A. Lewis, R J. Heron, R G. Clark, R P. Starrett, A V. Skougarevsky Jan 1996

Far-Infrared Measurements Of Cyclotron Resonance And Impurity Transitions In Bulk N-Gaas In Pulsed Magnetic Fields, R A. Lewis, R J. Heron, R G. Clark, R P. Starrett, A V. Skougarevsky

Faculty of Engineering and Information Sciences - Papers: Part A

The photoconductive response of n-GaAs has been measured under laser radiation in the wavelength range 71 to 513 /spl mu/m at temperatures as low as 400 mK and at magnetic fields as high as 42 T. A rich variety of spectral features are observed: cyclotron resonance, transitions associated with D/sup -/, and transitions to stable and metastable hydrogenic states. The use of a pulsed magnet has extended the magnetic field range over which data is available by a factor of three.


The Interpretation Of Laser Sensing Measurements For Blast Furnace Operations And Control, Peter C. Wall, R J Turner, Mark Hughes, Peter Huk, Ross J. Haywood, M J Mccarthy, Paul Zulli Jan 1994

The Interpretation Of Laser Sensing Measurements For Blast Furnace Operations And Control, Peter C. Wall, R J Turner, Mark Hughes, Peter Huk, Ross J. Haywood, M J Mccarthy, Paul Zulli

Faculty of Engineering and Information Sciences - Papers: Part A

Several laser-based sensors for use on blast furnaces have been developed and implemented, including a raceway sensor, burden level sensor (single point) and burden surface profiler. These sensors are based on the time-of-flight technique and give high levels of accuracy in all applications. The data obtained from the sensors during normal furnace operations are examined in light of the process models utilised by operators and for the interpretation of pulverised coal injection performance. Raceway sensory data obtained during a furnace blow-in are also discussed.