scholarly journals High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in-situ production

2013 ◽  
Vol 9 (3) ◽  
pp. 2817-2857 ◽  
Author(s):  
X. Faïn ◽  
J. Chappellaz ◽  
R. H. Rhodes ◽  
C. Stowasser ◽  
T. Blunier ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
High Resolution ◽  
Biomass Burning ◽  
Optical Feedback ◽  
Ice Core ◽  
High Amplitude ◽  
Enhanced Absorption ◽  
Co Concentrations ◽  
In Situ Production

Abstract. We present high-resolution measurements of carbon monoxide (CO) concentrations from continuous analysis of a shallow ice core from the North Greenland Eemian Ice Drilling project (NEEM-2011-S1). An Optical Feedback – Cavity Enhanced Absorption Spectrometer (OF-CEAS) was coupled to a continuous melter system during a 4-week laboratory-based measurement campaign. This analytical setup generates highly stable measurements of CO concentrations with an external precision of 7.8 ppbv (1 sigma) based on a comparison of replicate cores. The NEEM-2011-S1 CO record spans 1800 yr and exhibits highly variable concentrations at the scale of annual layers, ranging from 75 to 1327 ppbv. The most recent section of this record (i.e. since 1700 AD) agrees with existing discrete CO measurements from the Eurocore ice core and the deep NEEM firn. However, it is difficult to interpret in terms of atmospheric CO variation due to high frequency, high amplitude spikes in the data. 68% of the elevated CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which can be oxidized or photodissociated to produce CO in-situ. We suggest that elevated CO concentration features could present a new integrative proxy for past biomass burning history. Furthermore, the NEEM-2011-S1 record reveals an increase in baseline CO level prior to 1700 AD (129 m depth), with the concentration remaining high even for ice layers depleted in dissolved organic carbon (DOC). Overall, the processes driving in-situ production of CO within the NEEM ice are complex and may involve multiple chemical pathways.

scholarly journals High resolution measurements of carbon monoxide along a late Holocene Greenland ice core: evidence for in situ production

2014 ◽  
Vol 10 (3) ◽  
pp. 987-1000 ◽  
Author(s):  
X. Faïn ◽  
J. Chappellaz ◽  
R. H. Rhodes ◽  
C. Stowasser ◽  
T. Blunier ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
High Resolution ◽  
Fire History ◽  
Optical Feedback ◽  
Ice Core ◽  
Absolute Calibration ◽  
Enhanced Absorption ◽  
Co Concentrations ◽  
In Situ Production

Abstract. We present high-resolution measurements of carbon monoxide (CO) concentrations from a shallow ice core of the North Greenland Eemian Ice Drilling project (NEEM-2011-S1). An optical-feedback cavity-enhanced absorption spectrometer (OF-CEAS) coupled to a continuous melter system performed continuous, online analysis during a four-week measurement campaign. This analytical setup generated stable measurements of CO concentrations with an external precision of 7.8 ppbv (1σ), based on repeated analyses of equivalent ice core sections. However, this first application of this measurement technique suffered from a poorly constrained procedural blank of 48 ± 25 ppbv and poor accuracy because an absolute calibration was not possible. The NEEM-2011-S1 CO record spans 1800 yr and the long-term trends within the most recent section of this record (i.e., post 1700 AD) resemble the existing discrete CO measurements from the Eurocore ice core. However, the CO concentration is highly variable (75–1327 ppbv range) throughout the ice core with high frequency (annual scale), high amplitude spikes characterizing the record. These CO signals are too abrupt and rapid to reflect atmospheric variability and their prevalence largely prevents interpretation of the record in terms of atmospheric CO variation. The abrupt CO spikes are likely the result of in situ production occurring within the ice itself, although the unlikely possibility of CO production driven by non-photolytic, fast kinetic processes within the continuous melter system cannot be excluded. We observe that 68% of the CO spikes are observed in ice layers enriched with pyrogenic aerosols. Such aerosols, originating from boreal biomass burning emissions, contain organic compounds, which may be oxidized or photodissociated to produce CO within the ice. However, the NEEM-2011-S1 record displays an increase of ~0.05 ppbv yr−1 in baseline CO level prior to 1700 AD (129 m depth) and the concentration remains elevated, even for ice layers depleted in dissolved organic carbon (DOC). Thus, the processes driving the likely in situ production of CO within the NEEM ice may involve multiple, complex chemical pathways not all related to past fire history and require further investigation.

Continuous (CFA) CH4 record of the Elbrus ice core, Caucasus (preliminary results)

2020 ◽  
Author(s):  
Diana Vladimirova ◽  
Xavier Faïn ◽  
Patrick Ginot ◽  
Stanislav Kutuzov ◽  
Vladimir Mikhalenko
Keyword(s):  
High Resolution ◽  
Optical Feedback ◽  
Ice Core ◽  
Flow Analysis ◽  
Preliminary Results ◽  
Mixing Ratios ◽  
Enhanced Absorption ◽  
Ice Core Record ◽  
In Situ Production

<p>Methane (CH<sub>4</sub>) is the third most powerful greenhouse gas. However, its warming potential is two orders of magnitude higher than of carbon dioxide and its residence time in the atmosphere is only 9.1 ± 0.9 years. It makes CH<sub>4</sub> a good indicator of rapid climate variations both under natural conditions and due to the anthropogenic influence.</p><p>The Elbrus ice core was drilled in 2009 on the Western Plato (43°20’53.9’’N, 42°25’36.0’’E) at elevation 5115 m a.s.l. It is 182 m long and is dated back to 280 ± 400 CE (Common Era). The CH<sub>4</sub> mixing ratios were analyzed using a continuous flow analysis (CFA) system paired with optical-feedback cavity-enhanced absorption spectroscopy. The measurements campaign was organized at Institut des Géosciences de l'Environnement (IGE), Grenoble, France. This is a first high-resolution mid-latitude CH<sub>4</sub> record. The record aims to better constrain the past evolution of mid-latitude methane sources.</p><p>Here we present preliminary results of the methane concentration measurements of the Elbrus ice core in high-resolution (CFA CH<sub>4</sub> record). We observe in situ production (max level 2900 ppb) and a baseline. We inspect a potential origin of the multiple spikes in the high-resolution record. Supposedly, either an in-situ production in the dust-rich layers occurred or a gas dissolution in the melt layers took place. However, the possibility of in-situ production during continuous gas extraction has to be further studied. The identified melt layers can serve as an indicator of interrupted stable water isotopic signal and may be supportive in the regional temperature reconstructions based on the Elbrus ice core record. A cleaned off the spikes record is inspected for the natural variability of the CH<sub>4</sub> baseline concentration related to the short-term climate and methane emissions variability.</p>

Atmospheric history of carbon monoxide since preindustrial times reconstructed from multiple Greenland ice cores

2021 ◽  
Author(s):  
Xavier Faïn ◽  
Rachael Rhodes ◽  
Philip Place ◽  
Vasilii Petrenko ◽  
Kévin Fourteau ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
High Resolution ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Absolute Calibration ◽  
Chemical Compositions ◽  
Accumulation Rates ◽  
Mixing Ratios ◽  
Enhanced Absorption

<p>Carbon monoxide (CO) is a regulated pollutant and one of the key components determining the oxidizing capacity of the atmosphere. Obtaining a reliable record of atmospheric CO mixing ratios since pre-industrial times is necessary to evaluate climate-chemistry models in conditions different from today. We present high-resolution measurements of CO mixing ratios from ice cores drilled at five different sites on the Greenland ice sheet which experience a range of snow accumulation rates, mean surface temperatures, and different chemical compositions. An optical-feedback cavity-enhanced absorption spectrometer (OF-CEAS) was coupled to continuous melter systems and operated during four analytical campaigns conducted between 2013 and 2019. The CFA-based CO measurements exhibit excellent external precision (ranging 3.3 - 6.6 ppbv, 1σ), and achieve consistently low blanks (ranging from 4.1±1.2 to 12.6±4.4 ppbv). Good accuracy and absolute calibration of CFA-based CO records enable paleo-atmospheric interpretations. The five CO records all exhibit variability in CO mixing ratios that is too large and rapid to reflect past atmospheric mixing ratio changes. Complementary tests conducted on discrete ice samples demonstrate that such patterns are not related to the analytical process (i.e., production of CO from organics in the ice during melting), but very likely are related to in situ CO production within the ice before analyses. Evaluation of signal resolution and co-investigation of high-resolution records of CO and TOC show that past atmospheric CO concentration can be extracted from the records’ baselines at four sites with accumulation rates higher than 20 cm water equivalent per year (weq yr<sup>-1</sup>). However, such baselines should be taken as upper bounds of past atmospheric CO burden. CO records from four sites are combined to produce a multisite average ice core reconstruction of past atmospheric CO for the Northern Hemisphere high latitudes, covering the period from 1700 to 1957 CE. From 1700 to 1875 CE, this record reveals stable or slightly increasing values remaining in the 100-115 ppbv range. From 1875 to 1957 CE, the record indicates a monotonic increase from 114±4 ppbv to 147±6 ppbv. The ice-core multisite CO record exhibits an excellent overlap with the atmospheric CO record from Greenland firn air which span the 1950-2010 time period. The combined ice-core and firn air CO history, spanning 1700-2010 CE, largely exhibits patterns that are consistent with the recent anthropogenic and biomass burning CO emission inventories. This brand new time series will be compared with the most recent results from Earth System Models involved in the CMIP6-AerChemMIP multi-model exercise.</p>

scholarly journals In-Situ Radiocarbon Production by Neutrons and Muons in an Antarctic Blue Ice Field at Scharffenbergbotnen: A Status Report

Radiocarbon ◽  
2001 ◽  
Vol 43 (2B) ◽  
pp. 751-757 ◽  
Author(s):  
K van der Borg ◽  
W J M van der Kemp ◽  
C Alderliesten ◽  
A F M de Jong ◽  
R A N Lamers ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Extraction Method ◽  
Ice Core ◽  
Co2 Concentration ◽  
Status Report ◽  
Constant Ratio ◽  
Ice Field ◽  
Co Concentrations ◽  
In Situ Production

In the radiocarbon accelerator mass spectrometry (14C AMS) analysis of gases obtained in a dry extraction from a 52–m Antarctic ice core, we observed 14CO2 and 14CO concentrations decreasing with depth. The concentrations are explained in terms of in-situ production by neutrons and captured muons in ablating ice. The ratio of the 14CO2 concentration to that of 14CO has been found to be constant at 1.9 ± 0.3. The ablation rates obtained of 42 ± 18 cm.yr−1 and 40 ± 13 cm.yr−1 for the neutron and muon components, respectively, are about three times higher than observed from stake readings. The discrepancy may point to an incomplete extraction of the dry extraction method. Using the constant ratio in 14CO2 and 14CO concentrations we correct for the in-situ component in the trapped 14CO2 and deduce an age of 10,300 ± 900 BP for the ice core.

scholarly journals Northern Hemisphere atmospheric history of carbon monoxide since preindustrial times reconstructed from multiple Greenland ice cores

2021 ◽  
Author(s):  
Xavier Faïn ◽  
Rachael H. Rhodes ◽  
Place Philip ◽  
Vasilii V. Petrenko ◽  
Kévin Fourteau ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
High Resolution ◽  
Northern Hemisphere ◽  
Ice Core ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Chemical Compositions ◽  
Accumulation Rates ◽  
Mixing Ratios ◽  
Enhanced Absorption

Abstract. Carbon monoxide (CO) is a regulated pollutant and one of the key components determining the oxidizing capacity of the atmosphere. Obtaining a reliable record of atmospheric CO mixing ratios since pre-industrial times is necessary to evaluate climate-chemistry models in conditions different from today and to constrain past CO sources. We present high-resolution measurements of CO mixing ratios from ice cores drilled at five different sites on the Greenland ice sheet which experience a range of snow accumulation rates, mean surface temperatures, and different chemical compositions. An optical-feedback cavity-enhanced absorption spectrometer (OF-CEAS) was coupled to continuous melter systems and operated during four analytical campaigns conducted between 2013 and 2019. Overall, continuous flow analyses (CFA) of CO were carried out on over 700 m of ice. The CFA-based CO measurements exhibit excellent external precision (ranging 3.3-6.6 ppbv, 1sigma), and achieve consistently low blanks (ranging from 4.1+/-1.2 to 12.6+/-4.4 ppbv), enabling paleo-atmospheric interpretations. However the five CO records all exhibit variability too large and rapid to reflect past atmospheric mixing ratio changes. Complementary tests conducted on discrete ice samples demonstrate that these variations are not artifacts of the analytical method (i.e., production of CO from organics in the ice during melting), but very likely are related to in situ CO production within the ice before analysis. Evaluation of signal resolution and co-investigation of high-resolution records of CO and TOC show that past atmospheric CO variations can be extracted from the records’ baselines at four sites with accumulation rates higher than 20 cm water equivalent per year (weq yr-1). However, such baselines should be taken as upper bounds of past atmospheric CO burden. Baseline CO records from four sites are combined to produce a multisite average ice core reconstruction of past atmospheric CO for the Northern Hemisphere high latitudes, covering the period from 1700 to 1957 CE. From 1700 to 1875 CE, the record reveals stable or slightly increasing values in the 100-115 ppbv range. From 1875 to 1957 CE, the record indicates a monotonic increase from 114+/-4 ppbv to 147+/-6 ppbv. The ice-core multisite CO record exhibits an excellent overlap with the atmospheric CO record from Greenland firn air which spans the 1950-2010 time period. The combined ice-core and firn air CO history, spanning 1700-2010 CE provides useful constraints for future model studies of atmospheric changes since the preindustrial period.

scholarly journals What could have caused pre-industrial biomass burning emissions to exceed current rates?

2013 ◽  
Vol 9 (1) ◽  
pp. 289-306 ◽  
Author(s):  
G. R. van der Werf ◽  
W. Peters ◽  
T. T. van Leeuwen ◽  
L. Giglio
Keyword(s):  
Population Density ◽  
Biomass Burning ◽  
Transport Model ◽  
Ice Core ◽  
Ice Cores ◽  
Fire Emissions ◽  
Core Data ◽  
Mixing Ratios ◽  
The Past ◽  
Co Concentrations

Abstract. Recent studies based on trace gas mixing ratios in ice cores and charcoal data indicate that biomass burning emissions over the past millennium exceeded contemporary emissions by up to a factor of 4 for certain time periods. This is surprising because various sources of biomass burning are linked with population density, which has increased over the past centuries. We have analysed how emissions from several landscape biomass burning sources could have fluctuated to yield emissions that are in correspondence with recent results based on ice core mixing ratios of carbon monoxide (CO) and its isotopic signature measured at South Pole station (SPO). Based on estimates of contemporary landscape fire emissions and the TM5 chemical transport model driven by present-day atmospheric transport and OH concentrations, we found that CO mixing ratios at SPO are more sensitive to emissions from South America and Australia than from Africa, and are relatively insensitive to emissions from the Northern Hemisphere. We then explored how various landscape biomass burning sources may have varied over the past centuries and what the resulting emissions and corresponding CO mixing ratio at SPO would be, using population density variations to reconstruct sources driven by humans (e.g., fuelwood burning) and a new model to relate savanna emissions to changes in fire return times. We found that to match the observed ice core CO data, all savannas in the Southern Hemisphere had to burn annually, or bi-annually in combination with deforestation and slash and burn agriculture exceeding current levels, despite much lower population densities and lack of machinery to aid the deforestation process. While possible, these scenarios are unlikely and in conflict with current literature. However, we do show the large potential for increased emissions from savannas in a pre-industrial world. This is mainly because in the past, fuel beds were probably less fragmented compared to the current situation; satellite data indicates that the majority of savannas have not burned in the past 10 yr, even in Africa, which is considered "the burning continent". Although we have not considered increased charcoal burning or changes in OH concentrations as potential causes for the elevated CO concentrations found at SPO, it is unlikely they can explain the large increase found in the CO concentrations in ice core data. Confirmation of the CO ice core data would therefore call for radical new thinking about causes of variable global fire rates over recent centuries.

First continuous high-resolution aerosol record from the East Greenland Ice Core Project (EGRIP), covering the last 15,000 years

2020 ◽  
Author(s):  
Camilla Marie Jensen ◽  
Tobias Erhardt ◽  
Giulia Sinnl ◽  
Hubertus Fischer
Keyword(s):  
High Resolution ◽  
Biomass Burning ◽  
Forest Fires ◽  
Ice Core ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Background Level ◽  
Volcanic Eruptions ◽  
Atmospheric Conditions ◽  
Data Set

<p>Ice sheets are reliable archives of atmospheric impurities such as aerosols and gasses of both natural and anthropogenic origin. Impurity records from Greenland ice cores reveal much information about previous atmospheric conditions and long-range transport in the Northern hemisphere going back more than a hundred thousand years.</p><p>Here we present the data from the upper 1,411 m from the EGRIP ice core, measuring conductivity, dust, sodium, calcium, ammonium, and nitrate. These records contain information about ocean sources, transport of terrestrial dust, soil and vegetation emissions as well as biomass burning, volcanic eruptions, etc., covering approximately the past 15,000 years. This newly obtained data set is unique as it provides the first high-resolution information about several thousands of years of the mid-Holocene period in Greenland that none of the previous impurity records from the other deep Greenland ice cores had managed to cover before due to brittle ice. This will contribute to further understanding of the atmospheric conditions for the pre-industrial period.</p><p>The ammonium record contains peaks significantly higher than the background level. These peaks are caused by biomass burning or forest fires emitting plumes of ammonia large enough so that they can extend to the free troposphere and be efficiently transported all the way to the Greenland ice sheet. Here we present preliminary results of the wild fire frequency covering the entire Holocene, where the wild fires are defined as outliers in the ammonium record of annual means.</p>

scholarly journals In-situ high-resolution visualization of laser-induced periodic nanostructures driven by optical feedback

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Alberto Aguilar ◽  
Cyril Mauclair ◽  
Nicolas Faure ◽  
Jean-Philippe Colombier ◽  
Razvan Stoian
Keyword(s):  
High Resolution ◽  
Optical Feedback ◽  
Periodic Nanostructures

scholarly journals An 800 year high-resolution black carbon ice-core record from Lomonosovfonna, Svalbard

2018 ◽  
Author(s):  
Dimitri Osmont ◽  
Isabel A. Wendl ◽  
Loïc Schmidely ◽  
Michael Sigl ◽  
Carmen P. Vega ◽  
...  
Keyword(s):  
High Resolution ◽  
Black Carbon ◽  
20Th Century ◽  
Biomass Burning ◽  
Ice Core ◽  
Ice Cores ◽  
The Arctic ◽  
Snow Albedo ◽  
Decadal Scale

Abstract. Produced by the incomplete combustion of fossil fuel and biomass, black carbon (BC) contributes to Arctic warming by reducing snow albedo and thus triggering a snow-albedo feedback leading to increased snow melting. Therefore, it is of high importance to assess past BC emissions to better understand and constrain their role. However, only few long-term BC records are available from the Arctic, mainly originating from Greenland ice cores. Here, we present the first long-term and high-resolution refractory black carbon (rBC) record from Svalbard, derived from the analysis of two ice cores drilled at the Lomonosovfonna ice field in 2009 (LF-09) and 2011 (LF-11) and covering 800 years of atmospheric emissions. Our results show that rBC concentrations strongly increased from 1860 on due to anthropogenic emissions and reached two maxima, at the end of the 19th century and in the middle of the 20th century. No increase in rBC concentrations during the last decades was observed, which is corroborated by atmospheric measurements elsewhere in the Arctic but contradicts a previous study from another ice core from Svalbard. While melting may affect BC concentrations during periods of high temperatures, rBC concentrations remain well-preserved prior to the 20th century due to lower temperatures inducing little melt. Therefore, the preindustrial rBC record (before 1800), along with ammonium (NH4+), formate (HCOO−) and specific organic markers (vanillic acid (VA) and p-hydroxybenzoic acid (p-HBA)), was used as a proxy for biomass burning. Despite numerous single events, no long-term trend was observed over the time period 1222–1800 for rBC and NH4+. In contrast, formate, VA and p-HBA experience multi-decadal peaks reflecting periods of enhanced biomass burning. Most of the background variations and single peak events are corroborated by other ice-core records from Greenland and Siberia. We suggest that the paleofire record from the LF ice core primarily reflects biomass burning episodes from Northern Eurasia, induced by decadal-scale climatic variations.

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