David Thornton

David Thornton
EPA Tasmania

About

60
Publications
7,664
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
208
Citations
Citations since 2016
46 Research Items
184 Citations
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
20162017201820192020202120220102030405060
Additional affiliations
April 2012 - June 2022
The Commonwealth Scientific and Industrial Research Organisation
Position
  • Researcher

Publications

Publications (60)
Preprint
Full-text available
Here we present a newly developed ice core gas-phase proxy that directly samples a component of the large-scale atmospheric circulation: synoptic-scale pressure variability. Surface pressure variability weakly disrupts gravitational isotopic settling in the firn layer, which is recorded in krypton-86 excess (86Krxs). We validate 86Krxs using late H...
Presentation
Full-text available
Submission to 15th International Conference on Accelerator Mass Spectrometry 15-19 November 2021.
Technical Report
CSIRO Oceans and Atmosphere - GASLAB discrete flask data from Antarctic/Sub-Antarctic sampling sites, which is part of a global sampling network. Air samples were collected in glass flasks at Casey (CYA), Mawson (MAA), and Macquarie Island (MQA) and analyzed at CSIRO Aspendale Laboratories for methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O...
Conference Paper
The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 11 m) relative to present day. LIG sea level...
Article
Full-text available
The Southern Ocean occupies 14% of the Earth’s surface and plays a fundamental role in the global carbon cycle and climate. It provides a direct connection to the deep ocean carbon reservoir through biogeochemical processes that include surface primary productivity, remineralization at depth and the upwelling of carbon-rich water masses. However, t...
Article
Full-text available
The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level...
Conference Paper
To meet the aspirations of the Paris Agreement, deep and rapid cuts in greenhouse gas (GHG) emissions are required. Since cities are both the epicentres of anthropogenic GHG emissions and often more progressive than states and nations in enacting policies to curb emissions, there is considerable value in developing atmospheric observational and mod...
Article
Full-text available
Determining the feedbacks that modulate Southern Ocean carbon dynamics is key to understanding past and future climate. The global pause in rising atmospheric CO2 during the period of mid- to high-latitude southern surface cooling known as the Antarctic Cold Reversal (ACR, 14,700-12,700 years ago) provides an opportunity to disentangle competing in...
Article
Full-text available
Ice core records of the major atmospheric greenhouse gases (CO2, CH4, N2O) and their isotopologues covering recent centuries provide evidence of biogeochemical variations during the Late Holocene and pre-industrial periods and over the transition to the industrial period. These records come from a number of ice core and firn air sites and have been...
Poster
Full-text available
The formation of Antarctic Bottom Water (AABW) within the Weddell Sea Embayment (WSE) plays a major role in the Southern Ocean circulation and its interaction with the global climate system. Increasing importance is attributed to AABW in moderating the Earth's heat and carbon flux. However, historic trends in AABW formation are not well understood...
Conference Paper
Full-text available
The Southern Ocean plays a fundamental role in regulating global atmospheric CO2 levels, yet the underlying processes and feedbacks that control the carbon cycle during climate transitions remain unclear. Following the Last Glacial Termination (LGT), the rapid rise in atmospheric CO2 was interrupted by an enigmatic 1,900-year plateau during a perio...
Article
Full-text available
Ice core records of the major atmospheric greenhouse gases (CO2, CH4, N2O) and their isotopologues covering recent centuries provide evidence of biogeochemical variations during the Late-Holocene and Pre-Industrial Periods and over the transition to the Industrial Period. These records come from a number of ice core and firn air sites, and have bee...
Preprint
The future response of the Antarctic ice sheets to rising temperatures remains highly uncertain. A valuable analogue for assessing the sensitivity of Antarctica to warming is the Last Interglacial (129-116 kyr), when global sea level peaked 6 to 9 meters above present. Here we report a blue-ice record of ice-sheet and environmental change from the...
Poster
The Southern Ocean plays a fundamental role in regulating global atmospheric CO2 levels, yet the underlying processes and feedbacks that control carbon cycle during climate transitions remain unclear. Following the last glacial, the rapid and punctuated rise in atmospheric CO2 was interrupted by an enigmatic 1,900-year plateau during a period of pr...
Poster
The Weddell Sea Embayment (WSE) drains some 20% of the ice-mass of continental Antarctica, including sectors of the East and West Antarctic ice sheets and the Antarctic Peninsula, and plays a major role in the global ocean-climate system. Unfortunately, the WSE suffers from a relative dearth of records, limiting our understanding of multi-decadal t...
Presentation
The Last Interglacial (130 to 116 thousand years ago) is widely considered to have been warmer than today, but the timing and contribution of Antarctica to global sea level rise during this period remains uncertain. Here we report a new highly-resolved blue ice record close to the West Antarctic Ice Sheet grounding line that implies high-latitude o...
Presentation
Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000–11,650 yrs ago) allows us to disentangle ice-climate feedbacks that are key to improving future projections. Whilst the sequence of events during this period is reasonably well known, relatively poor chronological control has...
Poster
Greenhouse gas scenarios limiting future global warming to 2 C require immediate emissions reductions leading to net negative emissions later this century. Mitigation responses by the energy sector will initially involve low carbon intensity fuels such as natural gas and the geological storage of CO2 which may remove CO2 from the atmosphere when co...
Presentation
Monitoring areal sources of fugitive fossil fuel emissions
Presentation
Characterisation of Regional Fluxes of Methane in the Surat Basin, Queensland.
Poster
Full-text available
CSIRO has been active in identifying and quantifying methane emissions from a range of fossil fuel sources in Australia over the past decade.We present here a history of the development of our work in this domain. While we have principally focused on optimising the use of long term, fixed location, high precision monitoring, paired with both forwar...
Article
Full-text available
Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000–11,650 yrs ago) allows us to disentangle ice-climate feedbacks that are key to improving future projections. Whilst the sequence of events during this period is reasonably well-known, relatively poor chronological control has...
Poster
The 2000 year record of atmospheric CO2 provides evidence of natural variations of the carbon cycle and the impact of anthropogenic activities. These records have been used extensively to quantify the anthropogenic CO2 increase, to identify the start of the anthropocene, to provide radiative forcing for earth system models and to infer carbon-clima...
Poster
The 2000 year record of atmospheric CO2 provides evidence of natural variations of the carbon cycle and the impact of anthropogenic activities. These records have been used extensively to quantify the anthropogenic CO2 increase, to identify the start of the anthropocene, to provide radiative forcing for earth system models and to infer carbon-clima...
Poster
The 2000 year record of atmospheric CO2 provides evidence of natural variations of the carbon cycle and the impact of anthropogenic activities. These records have been used extensively to quantify the anthropogenic CO2 increase, to identify the start of the anthropocene, to provide radiative forcing for earth system models and to infer carbon-clima...
Poster
The 2000 year record of atmospheric CO2 provides evidence of natural variations of the carbon cycle and the impact of anthropogenic activities. These records have been used extensively to quantify the anthropogenic CO2 increase, to identify the start of the anthropocene, to provide radiative forcing for earth system models and to infer carbon-clima...
Poster
The 2000 year record of atmospheric CO2 provides evidence of natural variations of the carbon cycle and the impact of anthropogenic activities. These records have been used extensively to quantify the anthropogenic CO2 increase, to identify the start of the anthropocene, to provide radiative forcing for earth system models and to infer carbon-clima...
Poster
The Australian Greenhouse Gas Observation Network – current status and vision for the future.
Poster
In Antarctica, a reasonable coverage of ice core records exist for the last few hundred years, but beyond that there is poor spatial coverage of high-resolution well dated climate data over the last 2000 years7. The Aurora Basin North (ABN) study was designed to focus on generating a 2000 year annually resolved record in the data sparse inland East...
Conference Paper
Deliverables 2015-16: Trace gas measurements through Holocene to last glacial; Sensitivity of terrestrial carbon to climate (pre-industrial); Sensitivity of ocean carbon uptake to dust deposition; Carbon monoxide record for ACCESS chemistry (past century); Perfluorocarbons and halons over the past century.
Conference Paper
The AGAGE (Advanced Global Atmospheric Gases Experiment) program has historically measured in situ CH4 at Cape Grim via GC-FID in 40 minutely grab samples. By adding continuous, high precision in situ measurements of CH4 (Picarro cavity ringdown spectroscopy (CRDS)) at both Cape Grim, Tasmania, and Casey, Antarctica, a new feature has become appare...
Poster
Full-text available
Here we report preliminary analysis of biomarkers (including dissolved organic matter (DOM) and DNA) from the Patriot Hills blue ice area (BIA), from the Ellsworth Mountains in the Weddell Sea Embayment. Preliminary isotopic and multiple gas analysis (CO2 , CH4, N2O and CO) demonstrate that the Holocene comprises more than 50% of this unique 800m l...
Poster
Full-text available
Radiocarbon (14C) plays a crucial role in global carbon cycle investigations, with published measurements from modern day observations and pre-industrial measurements from tree rings. The 14C-CO2 pulse produced in the atmosphere by nuclear weapons testing in the 1960’s is also incorporated in air in open pores of firn before close-off in bubbles in...
Poster
Full-text available
Most of the Antarctic Ice Sheet has a snow/firn cover of approximately 100m that overlies the ice. Blue ice areas however provide an opportunity to access ice which has been dynamically tilted, stripped of snow and ablated at the surface via prevailing katabatic airflows. They also provide the opportunity to collect large samples of ice, which in t...
Conference Paper
During the last deglaciation (21,000 to 7,000years ago) global sea level rise was punctuated by several abrupt meltwater spikes triggered by the retreat of ice sheets and glaciers worldwide. However, the debate regarding the relative timing, geographical source and the physical mechanisms driving these rapid increases in sea level has catalyzed deb...
Conference Paper
Full-text available
Traditional ice coring often provides insufficient material to explore new approaches and develop new palaeoclimate and palaeoenvironmental proxies. Here we report the results from preliminary analysis of biomarkers (including dissolved organic matter (DOM) from the Patriot Hills blue ice area (BIA), from the Ellsworth Mountains in the Weddell Sea...
Conference Paper
Full-text available
During the last deglaciation (21,000 to 7,000 years ago) global sea level rise was punctuated by several abruptmeltwater spikes triggered by the retreat of ice sheets and glaciers world-wide. However, questions regarding therelative timing, geographical source and the physical mechanisms driving these rapid increases in sea level havecatalysed sign...
Conference Paper
Carbon monoxide (CO) has significant roles in tropospheric chemistry, including being a major sink for the hydroxyl radical which in turn controls the lifetimes of reactive greenhouse gases and ozone depleting gases. The main sources of CO are fossil fuel combustion, biomass burning and the oxidation of methane and non-methane hydrocarbons. Signifi...
Conference Paper
Full-text available
The “Earth Health” program in CSIRO’s Ocean & Atmosphere Flagship is continuing to expand its atmospheric composition measurement capability at Cape Grim BAPS and CSIRO’s Australian atmospheric observation network in general. In particular, at the developing Australian pilot tropical atmospheric observation site established at Gunn Point in Austral...
Conference Paper
Full-text available
COS is the most abundant sulphur containing trace gas in the atmosphere (Montzka et al., 2010). Its role as a precursor for stratospheric sulphate aerosols, which catalyse the destruction of ozone (O3) (Andreae and Crutzen, 1997), makes it an important gas to quantify contemporarily and characterise historically. The atmospheric COS budget is highl...
Conference Paper
Full-text available
Millennial changes in atmospheric trace gas composition are best determined from air enclosed in ice sheets. Air extracted from the open pores in firn and the bubbles in ice is measured to derive the past concentrations and isotopic ratios of the long lived trace gases. The significant increases observed in CO2, CH4 and N2O since about 1750 and the...
Article
Full-text available
The Latrobe Valley Air Monitoring Network was established to provide an assessment of the Latrobe Valley airshed to accept emissions from existing and future sources. Over several decades, meteorological and air quality data have been gathered at numerous sites throughout the Valley, thus establishing a well understood airshed. Air quality modellin...
Article
Full-text available
How emissions from different sources combine is of great importance when determining the overall impact of contaminant emissions. At any point within an airshed, measured pollutant concentrations are the result of all sources that are upwind of the recorder. Industrial emitters are the major source of sulphur dioxide emissions within the Marsden Po...
Article
Full-text available
As an aid to airshed management for the Marsden Point Region in New Zealand, two high-resolution simulations with eight point sources are performed with The Air Pollution Model (TAPM). The first simulation is for a two day period when high ground level concentrations of SO2 were detected at a monitoring site. For this two day period, the region was...
Article
The flow of organisms in lotic environments is known as Macroinvertebrate Stream Drift: a phenomenon that has long fascinated freshwater ecologists. Stream-dwelling organisms are often transported downstream in the water column in substantial numbers. Because they have limited swimming ability and the movement is apparently passive, the process is...

Network

Cited By