scholarly journals Commentary on “Atmospheric ionization by high-fluence, hard-spectrum solar proton events and their probable appearance in the ice core archive” by A.L. Melott et al. and “Nitrate ion spikes in ice cores not suitable as proxies for solar proton events” by

2016 ◽  
Vol 121 (6) ◽  
pp. 3034-3035 ◽  
Author(s):  
M. Sinnhuber
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Solar Proton ◽  
High Fluence ◽  
Nitrate Ion ◽  
Hard Spectrum ◽  
Solar Proton Events ◽  
Atmospheric Ionization

scholarly journals Atmospheric ionization by high-fluence, hard-spectrum solar proton events and their probable appearance in the ice core archive

2016 ◽  
Vol 121 (6) ◽  
pp. 3017-3033 ◽  
Author(s):  
Adrian L. Melott ◽  
Brian C. Thomas ◽  
Claude M. Laird ◽  
Ben Neuenswander ◽  
Dimitra Atri
Keyword(s):  
Ice Core ◽  
Solar Proton ◽  
High Fluence ◽  
Hard Spectrum ◽  
Solar Proton Events ◽  
Atmospheric Ionization

scholarly journals Comment on “Atmospheric ionization by high-fluence, hard spectrum solar proton events and their probable appearance in the ice core archive” by A. L. Melott et al.

2016 ◽  
Vol 121 (20) ◽  
pp. 12,484-12,489 ◽  
Author(s):  
K. A. Duderstadt ◽  
J. E. Dibb ◽  
C. H. Jackman ◽  
C. E. Randall ◽  
N. A. Schwadron ◽  
...  
Keyword(s):  
Ice Core ◽  
Solar Proton ◽  
High Fluence ◽  
Hard Spectrum ◽  
Solar Proton Events ◽  
Atmospheric Ionization

scholarly journals Nitrate ion spikes in ice cores not suitable as proxies for solar proton events

2016 ◽  
Vol 121 (6) ◽  
pp. 2994-3016 ◽  
Author(s):  
Katharine A. Duderstadt ◽  
Jack E. Dibb ◽  
Nathan A. Schwadron ◽  
Harlan E. Spence ◽  
Stanley C. Solomon ◽  
...  
Keyword(s):  
Ice Cores ◽  
Solar Proton ◽  
Nitrate Ion ◽  
Solar Proton Events

scholarly journals Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. (∼660 BC)

2019 ◽  
Vol 116 (13) ◽  
pp. 5961-5966 ◽  
Author(s):  
Paschal O’Hare ◽  
Florian Mekhaldi ◽  
Florian Adolphi ◽  
Grant Raisbeck ◽  
Ala Aldahan ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Solar Proton ◽  
Solar Proton Event ◽  
Proton Event ◽  
Production Rates ◽  
Cosmogenic Radionuclides ◽  
Solar Event ◽  
Carbon 14 ◽  
Order Of Magnitude

Recently, it has been confirmed that extreme solar proton events can lead to significantly increased atmospheric production rates of cosmogenic radionuclides. Evidence of such events is recorded in annually resolved natural archives, such as tree rings [carbon-14 (14C)] and ice cores [beryllium-10 (10Be), chlorine-36 (36Cl)]. Here, we show evidence for an extreme solar event around 2,610 years B.P. (∼660 BC) based on high-resolution10Be data from two Greenland ice cores. Our conclusions are supported by modeled14C production rates for the same period. Using existing36Cl ice core data in conjunction with10Be, we further show that this solar event was characterized by a very hard energy spectrum. These results indicate that the 2,610-years B.P. event was an order of magnitude stronger than any solar event recorded during the instrumental period and comparable with the solar proton event of AD 774/775, the largest solar event known to date. The results illustrate the importance of multiple ice core radionuclide measurements for the reliable identification of short-term production rate increases and the assessment of their origins.

List of Solar Proton Events in the 24 Cycle of Solar Activity (2009 ‒ 2019)

2019 ◽  
Author(s):  
◽  
Vitaly Ishkov ◽  
Yury Logachev ◽  
Galina Bazilevskaya ◽  
Elena Daibog ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Proton ◽  
Solar Proton Events

scholarly journals Spatial variations of local climate at Taylor Dome, Antarctica: implications for paleoclimate from ice cores

1994 ◽  
Vol 20 ◽  
pp. 219-225 ◽  
Author(s):  
E.D. Waddington ◽  
D.L. Morse
Keyword(s):  
Spatial Variability ◽  
Source Region ◽  
Ice Core ◽  
Ice Cores ◽  
Temperature Inversion ◽  
Related Factors ◽  
Local Climate ◽  
Air Masses ◽  
Air Temperatures ◽  
Inversion Strength

10m firn temperatures are commonly used on the Antarctic plateau to estimate mean annual air temperatures. 10m firn temperatures measured at Taylor Dome (also referred to as McMurdo Dome in the literature), Antarctica, are influenced by a factor other than altitude and latitude that varies systematically across Taylor Dome. Some inter-related factors possibly contributing to the modern temperature variability are differences in sensible heat from warm or cold air masses, differences in wind strength and source region, differences in temperature inversion strength and differences in cloudiness. Our preliminary data are compatible with spatially variable katabatic winds that could control the winter temperature inversion strength to provide a large part of the signal. This has implications for paleoclimate studies.(1) Variations of the stable isotopes δ18O and δD from ice cores are a proxy for paleotemperature. The isotope thermometer is calibrated by comparing local isotope ratios with corresponding measured temperatures. In order to derive a useful isotope-temperature calibration, we must understand the processes that control the modern spatial variability of temperature. (2) In order to quantify past changes in local climate, we must understand processes that influence local spatial variability. If those processes differed in the past, ice-core climate reconstruction would be affected in two ways: through alteration of the geochemical record and through alteration of deep ice and firn temperatures.

scholarly journals A Synoptic Scale Perspective on Greenland Ice Core δ18O Variability and Related Teleconnection Patterns

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 294
Author(s):  
Norel Rimbu ◽  
Monica Ionita ◽  
Gerrit Lohmann
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Synoptic Scale ◽  
Local Climate ◽  
Rossby Wave Breaking ◽  
Weather Patterns ◽  
Teleconnection Patterns ◽  
Climate Anomalies ◽  
The North ◽  
Oxygen Isotope Ratios

The variability of stable oxygen isotope ratios (δ18O) from Greenland ice cores is commonly linked to changes in local climate and associated teleconnection patterns. In this respect, in this study we investigate ice core δ18O variability from a synoptic scale perspective to assess the potential of such records as proxies for extreme climate variability and associated weather patterns. We show that positive (negative) δ18O anomalies in three southern and central Greenland ice cores are associated with relatively high (low) Rossby Wave Breaking (RWB) activity in the North Atlantic region. Both cyclonic and anticyclonic RWB patterns associated with high δ18O show filaments of strong moisture transport from the Atlantic Ocean towards Greenland. During such events, warm and wet conditions are recorded over southern, western and central part of Greenland. In the same time the cyclonic and anticyclonic RWB patterns show enhanced southward advection of cold polar air masses on their eastern side, leading to extreme cold conditions over Europe. The association between high δ18O winters in Greenland ice cores and extremely cold winters over Europe is partly explained by the modulation of the RWB frequency by the tropical Atlantic sea surface temperature forcing, as shown in recent modeling studies. We argue that δ18O from Greenland ice cores can be used as a proxy for RWB activity in the Atlantic European region and associated extreme weather and climate anomalies.

scholarly journals Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere

2021 ◽  
Vol 7 (22) ◽  
pp. eabc1379
Author(s):  
Pengfei Liu ◽  
Jed O. Kaplan ◽  
Loretta J. Mickley ◽  
Yang Li ◽  
Nathan J. Chellman ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Radiative Forcing ◽  
Ice Core ◽  
Ice Cores ◽  
Terrestrial Ecosystems ◽  
Rapid Expansion ◽  
Past Century ◽  
Fire Emissions ◽  
The Past ◽  
Fire Activity

Fire plays a pivotal role in shaping terrestrial ecosystems and the chemical composition of the atmosphere and thus influences Earth’s climate. The trend and magnitude of fire activity over the past few centuries are controversial, which hinders understanding of preindustrial to present-day aerosol radiative forcing. Here, we present evidence from records of 14 Antarctic ice cores and 1 central Andean ice core, suggesting that historical fire activity in the Southern Hemisphere (SH) exceeded present-day levels. To understand this observation, we use a global fire model to show that overall SH fire emissions could have declined by 30% over the 20th century, possibly because of the rapid expansion of land use for agriculture and animal production in middle to high latitudes. Radiative forcing calculations suggest that the decreasing trend in SH fire emissions over the past century largely compensates for the cooling effect of increasing aerosols from fossil fuel and biofuel sources.

Do Greenland Ice Cores Reflect NW European Interglacial Climate Variations?

1995 ◽  
Vol 43 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Eiliv Larsen ◽  
Hans Petter Sejrup ◽  
Sigfus J. Johnsen ◽  
Karen Luise Knudsen
Keyword(s):  
Western Europe ◽  
Ice Core ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
High Amplitude ◽  
Atlantic Water ◽  
Polar Front ◽  
Norwegian Sea ◽  
The Holocene ◽  
Climatic Evolution

AbstractThe climatic evolution during the Eemian and the Holocene in western Europe is compared with the sea-surface conditions in the Norwegian Sea and with the oxygen-isotope-derived paleotemperature signal in the GRIP and Renland ice cores from Greenland. The records show a warm phase (ca. 3000 yr long) early in the Eemian (substage 5e). This suggests that the Greenland ice sheet, in general, recorded the climate in the region during this time. Rapid fluctuations during late stage 6 and late substage 5e in the GRIP ice core apparently are not recorded in the climatic proxies from western Europe and the Norwegian Sea. This may be due to low resolution in the terrestrial and marine records and/or long response time of the biotic changes. The early Holocene climatic optimum recorded in the terrestrial and marine records in the Norwegian Sea-NW European region is not found in the Summit (GRIP and GISP2) ice cores. However, this warm phase is recorded in the Renland ice core. Due to the proximity of Renland to the Norwegian Sea, this area is probably more influenced by changes in polar front positions which may partly explain this discrepancy. A reduction in the elevation at Summit during the Holocene may, however, be just as important. The high-amplitude shifts during substage 5e in the GRIP core could be due to Atlantic water oscillating closer to, and also reaching, the coast of East Greenland. During the Holocene, Atlantic water was generally located farther east in the Norwegian Sea than during the Eemian.

scholarly journals Investigation of a cold-based ice apron on a high-mountain permafrost rock wall using ice texture analysis and micro-14C dating: a case study of the Triangle du Tacul ice apron (Mont Blanc massif, France)

2021 ◽  
pp. 1-8
Author(s):  
Grégoire Guillet ◽  
Susanne Preunkert ◽  
Ludovic Ravanel ◽  
Maurine Montagnat ◽  
Ronny Friedrich
Keyword(s):  
Radiocarbon Dating ◽  
Boundary Migration ◽  
Ice Core ◽  
Ice Cores ◽  
Shear Plane ◽  
High Mountain ◽  
14C Dating ◽  
Rock Wall ◽  
Major Mechanism ◽  
Mont Blanc Massif

Abstract The current paper studies the dynamics and age of the Triangle du Tacul (TDT) ice apron, a massive ice volume lying on a steep high-mountain rock wall in the French side of the Mont-Blanc massif at an altitude close to 3640 m a.s.l. Three 60 cm long ice cores were drilled to bedrock (i.e. the rock wall) in 2018 and 2019 at the TDT ice apron. Texture (microstructure and lattice-preferred orientation, LPO) analyses were performed on one core. The two remaining cores were used for radiocarbon dating of the particulate organic carbon fraction (three samples in total). Microstructure and LPO do not substantially vary with along the axis of the ice core. Throughout the core, irregularly shaped grains, associated with strain-induced grain boundary migration and strong single maximum LPO, were observed. Measurements indicate that at the TDT ice deforms under a low strain-rate simple shear regime, with a shear plane parallel to the surface slope of the ice apron. Dynamic recrystallization stands out as the major mechanism for grain growth. Micro-radiocarbon dating indicates that the TDT ice becomes older with depth perpendicular to the ice surface. We observed ice ages older than 600 year BP and at the base of the lowest 30 cm older than 3000 years.

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