Social and Behavioral Sciences Commons^™

Ch4, Co, And H2o Spectroscopy For The Sentinel-5 Precursor Mission: An Assessment With The Total Carbon Column Observing Network Measurements, A Galli, A Butz, R A. Scheepmaker, O Hasekamp, J Landgraf, P Tol, D Wunch, N M. Deutscher, G C. Toon, P O. Wennberg, D W. T Griffith, I Aben

Faculty of Science - Papers (Archive)

The TROPOspheric Monitoring Instrument (TROPOMI) will be part of ESA’s Sentinel-5 Precursor (S5P) satellite platform scheduled for launch in 2015. TROPOMI will monitor methane and carbon monoxide concentrations in the Earth’s atmosphere by measuring spectra of back-scattered sunlight in the short-wave infrared (SWIR).

Atmospheric Greenhouse Gases Retrieved From Sciamachy: Comparison To Ground-Based Fts Measurements And Model Results, O Schneising, P Bergamaschi, H Bovensmann, M Buchwitz, J P. Burrows, N M. Deutscher, D W. T Griffith, J Heymann, R Macatangay, J Messerschmidt, J Notholt, M Rettinger, M Reuter, R Sussmann, Voltaire A. Velazco, T Warneke, P O. Wennberg, D Wunch

Faculty of Science - Papers (Archive)

SCIAMACHY onboard ENVISAT (launched in 2002) enables the retrieval of global long-term columnaveraged dry air mole fractions of the two most important anthropogenic greenhouse gases carbon dioxide and methane (denoted XCO₂ and XCH₄). In order to assess the quality of the greenhouse gas data obtained with the recently introduced v2 of the scientific retrieval algorithm WFM-DOAS, we present validations with ground-based Fourier Transform Spectrometer (FTS) measurements and comparisons with model results at eight Total Carbon Column Observing Network (TCCON) sites providing realistic error estimates of the satellite data. Such validation is a prerequisite to assess the suitability …

Methane Retrievals From Greenhouse Gases Observing Satellite (Gosat) Shortwave Infrared Measurements: Performance Comparison Of Proxy And Physics Retrieval Algorithms, D Schepers, S Guerlet, A Butz, J Landgraf, C Frankenberg, O Hasekamp, J-F Blavier, N M. Deutscher, D W. T Griffith, F Hase, E Kyro, I Morino, V Sherlock, R Sussmann, I Aben

Faculty of Science - Papers (Archive)

We compare two conceptually different methods for determining methane column-averaged mixing ratios (X_CH4) from Greenhouse Gases Observing Satellite (GOSAT) shortwave infrared (SWIR) measurements. These methods account differently for light scattering by aerosol and cirrus. The proxy method retrieves a CO₂ column which, in conjunction with prior knowledge on CO₂ acts as a proxy for scattering effects. The physics-based method accounts for scattering by retrieving three effective parameters of a scattering layer. Both retrievals are validated on a 19-month data set using ground-based X_CH4 measurements at 12 stations of the Total Carbon Column Observing Network (TCCON), …

Retrieval Of Atmospheric Co2 With Enhanced Accuracy And Precision From Sciamachy: Validation With Fts Measurements And Comparison With Model Results, M Reuter, H Bovensmann, M Buchwitz, Jp Burrows, B Connor, Nicholas M. Deutscher, David W. Griffith, J Heymann, Gretchen Keppel-Aleks, Janina Messerschmidt, Justus Notholt, Christof Petri, J Robinson, O Schneising, V Sherlock, Voltaire A. Velazco, Thorsten Warneke, Paul O. Wennberg, Debra Wunch

Faculty of Science - Papers (Archive)

The Bremen Optimal Estimation differential optical absorption spectroscopy (DOAS) (BESD) algorithm for satellite based retrievals of XCO 2 (the column-average dry-air mole fraction of atmospheric CO 2) has been applied to Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) data. It uses measurements in the O 2-A absorption band to correct for scattering of undetected clouds and aerosols. Comparisons with precise and accurate ground-based Fourier transform spectrometer (FTS) measurements at four Total Carbon Column Observing Network (TCCON) sites have been used to quantify the quality of the new SCIAMACHY XCO 2 data set. Additionally, the results have been compared to …

The Australian Methane Budget: Interpreting Surface And Train-Borne Measurements Using A Chemistry Transport Model, A Fraser, C C. Miller, Paul Palmer, Nicholas M. Deutscher, Nicholas B. Jones, David W. Griffith

Faculty of Science - Papers (Archive)

We investigate the Australian methane budget from 2005-2008 using the GEOS-Chem 3D chemistry transport model, focusing on the relative contribution of emissions from different sectors and the influence of long-range transport. To evaluate the model, we use in situ surface measurements of methane, methane dry air column average (XCH 4) from ground-based Fourier transform spectrometers (FTSs), and train-borne surface concentration measurements from an in situ FTS along the north-south continental transect. We use gravity anomaly data from Gravity Recovery and Climate Experiment to describe the spatial and temporal distribution of wetland emissions and scale it to a prior emission estimate, …

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 …

Global Co(2) Fluxes Inferred From Surface Air-Sample Measurements And From Tccon Retrievals Of The Co(2) Total Column, Frederic Chevallier, Nicholas M. Deutscher, T J. Conway, P Ciais, L Ciattaglia, S Dohe, M Frohlich, A J. Gomez-Pelaez, David W. Griffith, F Hase, L Haszpra, Paul Krummel, E Kyro, C Labuschagne, R Lagenfelds, T Machidda, F Maignan, H Matsueda, I Morino, Justus Notholt, M Ramonet, Y Sawa, M Schmidt, V Sherlock, P Steele, K Strong, R Sussmann, Paul O. Wennberg, Steven C. Wofsy, D Worthy, Debra Wunch, M Zimnoch

Faculty of Science - Papers (Archive)

"We present the first estimate of the global distribution of CO(2) surface fluxes from 14 stations of the Total Carbon Column Observing Network (TCCON). The evaluation of this inversion is based on 1) comparison with the fluxes from a classical inversion of surface air-sample-measurements, and 2) comparison of CO(2) mixing ratios calculated from the inverted fluxes with independent aircraft measurements made during the two years analyzed here, 2009 and 2010. The former test shows similar seasonal cycles in the northern hemisphere and consistent regional carbon budgets between inversions from the two datasets, even though the TCCON inversion appears to be …

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

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

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 …

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. …

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

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. …

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 …

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

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

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

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 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 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 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 …

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

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 …

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 …

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

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 …

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 …