A5059459752- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Arctic and Antarctic ice dynamics
- Climate change and permafrost
- Polar Research and Ecology
- Tree-ring climate responses
- Atmospheric chemistry and aerosols
- Fire effects on ecosystems
- Atmospheric Ozone and Climate
- Climate variability and models
- Isotope Analysis in Ecology
- Winter Sports Injuries and Performance
- Spectroscopy and Quantum Chemical Studies
- Geological Studies and Exploration
- Planetary Science and Exploration
- Mass Spectrometry Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Spectroscopy and Laser Applications
- Chemical and Physical Properties of Materials
- Groundwater and Isotope Geochemistry
- Heavy metals in environment
- Electrohydrodynamics and Fluid Dynamics
- Chemical Analysis and Environmental Impact
Nevada System of Higher Education
2015-2021
Desert Research Institute
2012-2021
The University of Adelaide
2006-2017
The University of Tokyo
2011
Flinders University
2008
Volcanism is a natural climate forcing causing short‐term variations in temperatures. Histories of volcanic eruptions are needed to quantify their role variability and assess human impacts. We present two new seasonally resolved, annually dated non‐sea‐salt sulfur records from polar ice cores—WAIS Divide (WDC06A) West Antarctica spanning 408 B.C.E. 2003 C.E. NEEM (NEEM‐2011‐S1) Greenland 78 1997 C.E.—both analyzed using high‐resolution continuous flow analysis coupled mass spectrometers. The...
Abstract. We present the WD2014 chronology for upper part (0–2850 m; 31.2 ka BP) of West Antarctic Ice Sheet (WAIS) Divide (WD) ice core. The is based on counting annual layers observed in chemical, dust and electrical conductivity records. These are caused by seasonal changes source, transport, deposition aerosols. measurements were interpreted manually with aid two automated methods. validated comparing to high-accuracy, absolutely dated chronologies. For Holocene, cosmogenic isotope...
The causal mechanisms responsible for the abrupt climate changes of Last Glacial Period remain unclear. One major difficulty is dating ice-rafted debris deposits associated with Heinrich events: Extensive iceberg influxes into North Atlantic Ocean linked to global impacts on and biogeochemistry. In a new ice core record atmospheric methane ultrahigh temporal resolution, we find increases within stadials 1, 2, 4, 5 that, uniquely, have no counterparts in Greenland temperature proxies. Using...
The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from Greenland NEEM core to reconstruct environmental alterations in source regions accompanying these changes. Separating transport effects, find strongly reduced terrestrial biogenic emissions glacial times reflecting net loss of vegetated...
Abstract. Biomass burning is a major source of greenhouse gases and influences regional to global climate. Pre-industrial fire-history records from black carbon, charcoal other proxies provide baseline estimates biomass at local scales spanning millennia, are thus useful examine the role fire in carbon cycle climate system. Here we use specific biomarker levoglucosan together with ammonium concentrations North Greenland Eemian (NEEM) ice cores (77.49° N, 51.2° W; 2480 m a.s.l) over past 2000...
Significance Cold and dry glacial-state climate conditions persisted in the Southern Hemisphere until approximately 17.7 ka, when paleoclimate records show a largely unexplained sharp, nearly synchronous acceleration deglaciation. Detailed measurements Antarctic ice cores document exactly at that time unique, ∼192-y series of massive halogen-rich volcanic eruptions geochemically attributed to Mount Takahe West Antarctica. Rather than coincidence, we postulate halogen-catalyzed stratospheric...
Interior Antarctica is among the most remote places on Earth and was thought to be beyond reach of human impacts when Amundsen Scott raced South Pole in 1911. Here we show detailed measurements from an extensive array 16 ice cores quantifying substantial toxic heavy metal lead pollution at throughout by 1889 – beating polar explorers more than 22 years. Unlike Arctic where peaked 1970s, as high early 20th century any time since industrialization. The similar timing magnitude changes...
Abstract A comprehensive record (WHV2020) of explosive volcanic eruptions in the last 11,000 years is reconstructed from West Antarctica Ice Sheet Divide deep ice core (WDC). The chronological list 426 large Southern Hemisphere and low latitudes during Holocene are highest quality all records cores, owing to high‐resolution chemical measurement exceptionally accurate WDC timescale. No apparent trend found frequency (number per millennium) eruptions, number most recent millennium (1,000–2,000...
Abstract Interpretation of ice core trace gas records depends on an accurate understanding the processes that smooth atmospheric signal in firn. Much work has been done to understand affecting air transport open pores firn, but a paucity data from trapped bubbles firn‐ice transition region limited ability constrain effect bubble closure processes. Here we present high‐resolution measurements firn density, methane concentrations, nitrogen isotopes, and total content show layering at West...
Abstract Ice core records from Antarctica show mostly synchronous temperature variations during the last deglacial transition, an indication that climate of entire continent reacted as one unit to global changes. However, a record Taylor Dome ice in Ross Sea sector East has been suggested rapid warming, similar style and with Oldest Dryas—Bølling warming Greenland. Since publication record, number lines evidence have this interpretation is incorrect reflects errors underlying time scale. The...
Abstract The sources and transport pathways of aerosol species in Antarctica remain uncertain, partly due to limited seasonally resolved data from the harsh environment. Here, we examine seasonal cycles major ions three high‐accumulation West Antarctic ice cores for new information regarding origin species. A method continuous acidity measurement is exploited provide a comprehensive, charge‐balance approach assessing non‐sea‐salt (nss) average nss‐anion composition 41% sulfate (SO 4 2− ),...
We present a detailed comparison between subsequent versions of commercially available wavelength-scanned cavity ring-down water isotope analysers (L2120-i and L2130-i, Picarro Inc.). The are used in parallel continuous mode by adaption low-volume flash evaporation module. Application the to ice-core analysis is assessed measurements glacial from Severnaya Zemlya with discrete isotope-ratio mass spectrometry performed on samples same ice-core. great advances instrument versions, particularly...
Abstract. Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved cores have both been proposed as indicators conditions. In this study, two from central north-eastern Greenland were analysed at sub-annual resolution MSA (CH3SO3H) bromine, covering the time period 1750–2010. We examine correlations between core HadISST1 ICE dataset consult back trajectories to infer likely...
Abstract. Advances in trace gas analysis allow localised, non-atmospheric features to be resolved ice cores, superimposed on the coherent atmospheric signal. These high-frequency signals could not have survived low-pass filter effect that diffusion firn exerts history and therefore do result from changes composition at sheet surface. Using continuous methane (CH4) records obtained five polar we characterise these explore their origin. Isolated samples, enriched CH4 Tunu13 (Greenland) record...
Abstract. We present the WD2014 chronology for upper part (0–2850 m, 31.2 ka BP) of West Antarctic Ice Sheet (WAIS) Divide ice core. The is based on counting annual layers observed in chemical, dust and electrical conductivity records. These are caused by seasonal changes source, transport, deposition aerosols. measurements were interpreted manually with aid two automated methods. validated comparing to high-accuracy, absolutely dated chronologies. For Holocene, cosmogenic isotope records...
Abstract Knowledge on the occurrence rate of extreme solar storms is strongly limited by relatively recent advent satellite monitoring Sun. To extend our perspective prior to era and because atmospheric ionization induced energetic particles (SEPs) can lead production odd nitrogen, nitrate spikes in ice cores have been tentatively used document both intensity past SEP events. However, reliability use records as a proxy for events debated. This partly due equivocal detection single possible...
We present the first long-term, highly resolved prokaryotic cell concentration record obtained from a polar ice core. This record, West Antarctic Ice Sheet (WAIS) Divide (WD) core, spanned Last Glacial Maximum (LGM) to early Holocene (EH) and showed distinct fluctuations in coincident with major climatic states. The time series also revealed ~1,500-year periodicity greater amplitude during Deglaciation (LDG). Higher lower variability occurred LGM EH than LDG. A sevenfold decrease coincided...
Abstract. The role of sea ice in the Earth climate system is still under debate, although it known to influence albedo, ocean circulation, and atmosphere–ocean heat gas exchange. Here we present a reconstruction 1950 1998 AD Laptev Sea based on Akademii Nauk core (Severnaya Zemlya, Russian Arctic). chemistry halogens bromine (Br) iodine (I) strongly active influenced by dynamics, terms physical, chemical biological process. Bromine reacts surface autocatalyzing "bromine explosion" events,...
We investigated solvation structures of I(-) and Na(+) on an aqueous solution surface by photodetachment spectroscopy mass spectrometry. An NaI was introduced into the vacuum as a continuous liquid flow (liquid beam), beam irradiated with UV laser pulse. The abundance electrons emitted excitation measured function wavelength (photodetachment spectroscopy). For concentrated NaI, we observe absorption peak at longer wavelengths than charge-transfer-to-solvent band in solution. This feature is...