A5026296507- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Ionosphere and magnetosphere dynamics
- Air Quality Monitoring and Forecasting
- Calibration and Measurement Techniques
- Climate variability and models
- Soil Geostatistics and Mapping
- Groundwater flow and contamination studies
- Higher Education Governance and Development
- Water Quality Monitoring and Analysis
- Spectroscopy and Laser Applications
- Geochemistry and Geologic Mapping
- Atmospheric aerosols and clouds
- Solar and Space Plasma Dynamics
- Higher Education Learning Practices
- Regional Development and Policy
- Cryospheric studies and observations
- Hydraulic Fracturing and Reservoir Analysis
- Ultrasound Imaging and Elastography
- Radio Wave Propagation Studies
- Ultrasound and Hyperthermia Applications
- Chemical Safety and Risk Management
- Mining Techniques and Economics
- Knee injuries and reconstruction techniques
University of Saskatchewan
2012-2022
Diagnostics Research Group
2022
Royal Netherlands Meteorological Institute
2021
National Centre for Atmospheric Science
2021
University of East Anglia
2021
National Institute of Meteorology
2015
Focused Ultrasound Foundation
2015
Airparif
2008
Boston Medical Center
2002
Boston University
2002
Abstract. Ozone forms in the Earth's atmosphere from photodissociation of molecular oxygen, primarily tropical stratosphere. It is then transported to extratropics by Brewer–Dobson circulation (BDC), forming a protective ozone layer around globe. Human emissions halogen-containing ozone-depleting substances (hODSs) led decline stratospheric until they were banned Montreal Protocol, and since 1998 upper stratosphere rising again, likely recovery halogen-induced losses. Total column...
Abstract. Ozone profile trends over the period 2000 to 2016 from several merged satellite ozone data sets and ground-based measured by four techniques at stations of Network for Detection Atmospheric Composition Change indicate significant increases in upper stratosphere, between 35 48 km altitude (5 1 hPa). Near 2 hPa (42 km), has been increasing about 1.5 % per decade tropics (20° S 20° N), 2.5 60° latitude bands both hemispheres. At levels below hPa), are smaller not statistically...
Abstract. Trends in the vertical distribution of ozone are reported and compared for a number new recently revised data sets. The amount ozone-depleting compounds stratosphere (as measured by equivalent effective stratospheric chlorine – EESC) was maximised second half 1990s. We examine periods before after peak to see if any change trend is discernible record that might be attributable EESC trend, though no attribution attempted. Prior 1998, trends upper (~ 45 km, 4 hPa) found −5 −10 % per...
Abstract. This paper presents extensive {bias determination} analyses of ozone observations from the Atmospheric Chemistry Experiment (ACE) satellite instruments: ACE Fourier Transform Spectrometer (ACE-FTS) and Measurement Aerosol Extinction in Stratosphere Troposphere Retrieved by Occultation (ACE-MAESTRO) instrument. Here we compare latest data products ACE-FTS ACE-MAESTRO with coincident nearly 20 satellite-borne, airborne, balloon-borne ground-based instruments, analysing volume mixing...
Abstract. After decades of depletion in the 20th century, near-global ozone now shows clear signs recovery upper stratosphere. The column, however, has remained largely constant since turn mainly due to evolution lower stratospheric ozone. In tropical stratosphere, is expected decrease as a consequence enhanced upwelling driven by increasing greenhouse gas concentrations, and this consistent with observations. There recent evidence, that mid-latitude continues well, contrary model...
Abstract. The OSIRIS instrument onboard the Odin spacecraft routinely measures vertical profiles of spectrally dispersed, limb scattered sunlight from upper troposphere into lower mesosphere. These measurements are used to retrieve ozone number density profile using SaskMART Multiplicative Algebraic Reconstruction Technique, which is a one dimensional modification an existing two-dimensional tomographic retrieval algorithm. retrieved extends cloud top 60 km. In absence clouds down 10 This...
Abstract. Stratospheric ozone profile measurements from the Aerosol and Gas Experiment~(SAGE) II satellite instrument (1984–2005) are combined with those Optical Spectrograph InfraRed Imager System (OSIRIS) on Odin (2001–Present) to quantify interannual variability decadal trends in stratospheric between 60° S N. These data merged into a multi-instrument, long-term record (1984–present) by analyzing during overlap period of 2002–2005 when both instruments were operational. The deseasonalized...
Abstract. In this paper, we present a merged dataset of ozone profiles from several satellite instruments: SAGE II on ERBS, GOMOS, SCIAMACHY and MIPAS Envisat, OSIRIS Odin, ACE-FTS SCISAT, OMPS Suomi-NPP. The is created in the framework European Space Agency Climate Change Initiative (Ozone_cci) with aim analyzing stratospheric trends. For dataset, used latest versions original datasets. datasets individual instruments have been extensively validated intercompared; only those which are good...
Abstract. In the framework of SI2N (SPARC (Stratosphere-troposphere Processes And their Role in Climate)/IO3C (International Ozone Commission)/IGACO-O3 (Integrated Global Atmospheric Chemistry Observations – Ozone)/NDACC (Network for Detection Composition Change)) initiative, several long-term vertically resolved merged ozone data sets produced from satellite measurements have been analysed and compared. This paper presents an overview methods, assumptions, challenges involved constructing...
Abstract. In this work, we analyze the seasonal dependence of ozone trends in stratosphere using four long-term merged data sets, SAGE-CCI-OMPS, SAGE-OSIRIS-OMPS, GOZCARDS, and SWOOSH, which provide more than 30 years monthly zonal mean profiles stratosphere. We focus here on between 2000 2018. All sets show similar results, although some discrepancies are observed. upper stratosphere, positive throughout all seasons majority latitudes. The largest upper-stratospheric observed during local...
Abstract. A small long-term drift in the Optical Spectrograph and Infrared Imager System (OSIRIS) stratospheric ozone product, manifested mostly since 2012, is quantified attributed to a changing bias limb pointing knowledge of instrument. correction this using predictable shape measured radiance profile implemented applied within OSIRIS retrieval algorithm. This new data version 5.10, displays substantially better both long- short-term agreement with Microwave Limb Sounder (MLS) throughout...
Abstract. The Stratosphere-troposphere Processes and their Role in Climate (SPARC) Data Initiative (SPARC, 2017) performed the first comprehensive assessment of currently available stratospheric composition measurements obtained from an international suite space-based limb sounders. initiative's main objectives were (1) to assess state data availability, (2) compile time series vertically resolved, zonal monthly mean trace gas aerosol fields, (3) perform a detailed intercomparison these...
Abstract. In this paper, we present a HARMonized dataset of OZone profiles (HARMOZ) based on limb and occultation measurements from Envisat (GOMOS, MIPAS SCIAMACHY), Odin (OSIRIS, SMR) SCISAT (ACE-FTS) satellite instruments. These provide high-vertical-resolution ozone covering the altitude range upper troposphere up to mesosphere in years 2001–2012. HARMOZ has been created framework European Space Agency Climate Change Initiative project. The harmonized consists original retrieved each...
Abstract. In this paper, we present the MErged GRIdded Dataset of Ozone Profiles (MEGRIDOP) in stratosphere with a resolved longitudinal structure, which is derived from data six limb and occultation satellite instruments: GOMOS, SCIAMACHY MIPAS on Envisat, OSIRIS Odin, OMPS Suomi-NPP, MLS Aura. The merged dataset was generated as contribution to European Space Agency Climate Change Initiative project (Ozone_cci). period time series ozone profiles late 2001 until end 2018. monthly mean...
Abstract. We have extended the satellite-based ozone anomaly time series to present (December 2012) by merging SAGE II (Stratospheric Aerosol and Gas Experiment II) with OSIRIS (Optical Spectrograph Infrared Imager System) correcting for small bias (~0.5%) between them, determined using their temporal overlap of 4 years. Analysis merged data set (1984–2012) shows a statistically significant negative trend at all altitudes in 18–25 km range, including (−4.6 ± 2.6)% decade−1 19.5 where...
A new algorithm, SaskMART, is presented that uses observations of limb-scattered sunlight and a radiative transfer model to determine the ozone number-density profile up 35 km altitude. In practice, clouds limit lower extent retrieval around 15 but if troposphere clear can be extended altitudes as low 10 km. SaskMART an iterative Multiplicative Algebraic Reconstruction Technique generates accurate results insensitive initial estimate profile. Examples are using OSIRIS radiance measurements...
Abstract. The Optical Spectrograph and InfraRed Imaging System (OSIRIS) on board the Odin spacecraft has been taking limb-scattered measurements of ozone number density profiles from 2001–present. Stratospheric Aerosol Gas Experiment II (SAGE II) took solar occultation densities 1984–2005 used in many studies long-term trends. We present characterization OSIRIS SaskMART v5.0× against new SAGE v7.00 for 2001–2005, period over which these two missions had overlap. This information can be to...
Abstract The stratospheric quasi‐biennial oscillation (QBO) dominates interannual variability of dynamical variables and trace constituents in the tropical stratosphere provides a natural experiment to test circulation‐chemistry interactions. This work quantifies relationships among ozone (O 3 ), reactive nitrogen (NO y source gas N 2 O, their links QBO, based on satellite constituent measurements meteorological data spanning 2005–2014 (over four QBO cycles). Data include O , HNO from Aura...
Abstract. The Optical Spectrograph and Infra-Red Imager System (OSIRIS) the Atmospheric Chemistry Experiment (ACE) have been taking measurements from space since 2001 2003, respectively. This paper presents intercomparisons between ozone NO2 measured by ACE OSIRIS satellite instruments ground-based at Polar Environment Research Laboratory (PEARL), which is located Eureka, Canada (80° N, 86° W) operated Canadian Network for Detection of Change (CANDAC). included in this study are four...
Abstract. A new retrieval algorithm for OSIRIS (Optical Spectrograph and Infrared Imager System) nitrogen dioxide (NO2) profiles is described validated. The relies on spectral fitting to obtain slant column densities of NO2, followed by inversion using an algebraic reconstruction technique the SaskTran spherical radiative transfer model (RTM) vertical local number density. validation covers different latitudes (tropical polar), years (2002–2012), all seasons (winter, spring, summer, autumn),...
The need to collect data representative of overall urban pollution is all-important in order monitor the population exposure. High spatial resolution monitoring using diffusive samplers allows studying pollutant distribution, thus enabling deeper investigation their generation and diffusion mechanisms. Nevertheless, such a campaign has certain cost. In this study we point out how find best compromise between number necessary measurements affordable costs for campaigns. We also describe an...
Abstract. Sodium airglow is generated when excited sodium atoms emit electromagnetic radiation while they are relaxing from an state into a lower energetic state. This radiation, the two D lines at 589.0 and 589.6 nm, can usually be detected space or ground. nightglow occurs times sun not present excitation of result chemical reaction with ozone. The detection means to determine amount in earth's mesosphere thermosphere (MLT). In this study, we time series monthly mean concentration...
Abstract. In spring 2011, the Arctic polar vortex was stronger than in any other year on record. As started to break up April, ozone and NO2 columns were measured with UV-visible spectrometers above Polar Environment Atmospheric Research Laboratory (PEARL) Eureka, Canada (80.05° N, 86.42° W) using differential optical absorption spectroscopy (DOAS) technique. These ground-based column measurements complemented by Ozone Monitoring Instrument (OMI) Optical Spectrograph Infra-Red Imager System...