scholarly journals A Northern Hemisphere Volcanic Chemistry Record (1869–1984) and Climatic Implications Using a South Greenland Ice Core

1990 ◽  
Vol 14 ◽  
pp. 176-182 ◽  
Author(s):  
W.B. Lyons ◽  
P.A. Mayewski ◽  
M.J. Spencer ◽  
M.S. Twickler ◽  
T.E. Graedel
Keyword(s):  
Global Climate ◽  
Regional Climate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Chemical Signatures ◽  
Time Period ◽  
Tree Ring Data ◽  
Long Term Trends ◽  
Major Chemical

The effect of volcanic emission of acidic aerosols on climate is well documented. The presence of acid droplets in the stratosphere can reduce transmissivity and hence decrease surface temperatures. Since the amount and chemical composition of erupted material has important effects on regional climate, knowledge of past volcanic events is of extreme importance. Detailed glaciochemical records provide the only milieu wherein the geochemistry of paleovolcanic events can be fully documented. We present a detailed sulfate and chloride record from an ice core drilled at site 20 D, 40 km SW of Dye 3 in southern Greenland. The record spans the time period 1869–1984 with chemical analyses of approximately eight samples per year. Time series decomposition and locally weighted scatter plot smoothing techniques were used to extract long term trends from the data so that individual volcanic eruptions could be documented. A number of events identified here have been unnoticed previously and a high percentage of the major chemical signatures documenting these events is associated with large decreases in temperature in the latitudinal zone 60–90 °N. Many authors have pointed out that the amount of volcanic acids such as HCl and H2SO4 injected into the atmosphere has a very important influence on global climate, yet this volcanic input has been difficult to quantify prior to ∼1960. Our data help to alleviate this problem. These individual events can be compared to available frost tree ring data from North America, further establishing a volcanism-climatic linkage.

scholarly journals A Northern Hemisphere Volcanic Chemistry Record (1869–1984) and Climatic Implications Using a South Greenland Ice Core

1990 ◽  
Vol 14 ◽  
pp. 176-182 ◽  
Author(s):  
W.B. Lyons ◽  
P.A. Mayewski ◽  
M.J. Spencer ◽  
M.S. Twickler ◽  
T.E. Graedel
Keyword(s):  
Global Climate ◽  
Regional Climate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Chemical Signatures ◽  
Time Period ◽  
Tree Ring Data ◽  
Long Term Trends ◽  
Major Chemical

The effect of volcanic emission of acidic aerosols on climate is well documented. The presence of acid droplets in the stratosphere can reduce transmissivity and hence decrease surface temperatures. Since the amount and chemical composition of erupted material has important effects on regional climate, knowledge of past volcanic events is of extreme importance. Detailed glaciochemical records provide the only milieu wherein the geochemistry of paleovolcanic events can be fully documented. We present a detailed sulfate and chloride record from an ice core drilled at site 20 D, 40 km SW of Dye 3 in southern Greenland. The record spans the time period 1869–1984 with chemical analyses of approximately eight samples per year. Time series decomposition and locally weighted scatter plot smoothing techniques were used to extract long term trends from the data so that individual volcanic eruptions could be documented. A number of events identified here have been unnoticed previously and a high percentage of the major chemical signatures documenting these events is associated with large decreases in temperature in the latitudinal zone 60–90 °N. Many authors have pointed out that the amount of volcanic acids such as HCl and H2SO4injected into the atmosphere has a very important influence on global climate, yet this volcanic input has been difficult to quantify prior to ∼1960. Our data help to alleviate this problem. These individual events can be compared to available frost tree ring data from North America, further establishing a volcanism-climatic linkage.

scholarly journals Long-term trends in the frequency of severe cyclones of Bay of Bengal : Observations and simulations

MAUSAM ◽  
2021 ◽  
Vol 58 (1) ◽  
pp. 59-66
Author(s):  
O. P. SINGH
Keyword(s):  
Tropical Cyclones ◽  
Bay Of Bengal ◽  
Climate Model ◽  
Model Simulation ◽  
Global Climate ◽  
Regional Climate ◽  
North Indian Ocean ◽  
Anthropogenic Activity ◽  
Long Term Trends

The east coast of India and the coasts of Bangladesh, Myanmar and Sri Lanka are vulnerable to the incidence of tropical cyclones of the Bay of Bengal. Every year these cyclones inflict heavy loss of life and property in this region. Global climate change resulting from anthropogenic activity is likely to manifest itself in the weather and climate of the Bay of Bengal region also. The long-term trends in the frequency and intensity of tropical cyclones of the Bay of Bengal during intense cyclonic months May, October and November is one such problem which has been addressed in the present paper.Utilizing the existing data of 129 years (1877-2005) pertaining to the tropical cyclone frequency and intensity in the Bay of Bengal during May, October and November, a study was undertaken to investigate the trends in the frequency of Severe Cyclonic Storms (SCS) during past decades. The results of the trend analysis reveal that the SCS frequency over the Bay of Bengal has registered significant increasing trends in past 129 years during the intense cyclonic months. It may be emphasized that these trends are long-term trends for more than hundred years based on statistical analyses which do not necessarily imply that SCS frequency has increased continuously decade after decade. As a matter of fact there has been a slight decrease in SCS frequency after peaking in the pentad 1966-1970, but this does not alter the long-term trend much. The intensification rate during November, which accounts for highest number of intense cyclones in the north Indian Ocean, has registered a steep rise of 26% per hundred years, implying that a tropical depression forming in the Bay of Bengal during November has a high probability to reach to severe cyclone stage. A regional climate model simulation revealed the enhanced cyclogenesis in the Bay of Bengal during May, October and November as a result of increased anthropogenic emissions in the atmosphere

Chemical Composition of Ice Containing Tephra Layers in the Byrd Station Ice Core, Antarctica

1988 ◽  
Vol 30 (3) ◽  
pp. 315-330 ◽  
Author(s):  
Julie M. Palais ◽  
Philip R. Kyle
Keyword(s):  
Chemical Composition ◽  
Silicate Glass ◽  
Residence Time ◽  
Volcanic Ash ◽  
Global Climate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Tephra Layers ◽  
The Antarctic ◽  
Hydrolysis Of

The chemical composition of ice containing tephra (volcanic ash) layers in 22 sections of the Byrd Station ice core was examined to determine if the volcanic eruptions affected the chemical composition of the atmosphere and precipitation in the vicinity of Byrd Station. The liquid conductivity, acidity, sulfate, nitrate, aluminum, and sodium concentrations of ice samples deposited before, during, and after the deposition of the tephra layers were analyzed. Ice samples that contain tephra layers have, on average, about two times more sulfate and three to four times more aluminum than nonvolcanic ice samples. The acidity of ice samples associated with tephra layers is lowered by hydrolysis of silicate glass and minerals. Average nitrate, sodium, and conductivity are the same in all samples. Because much of the sulfur and chlorine originally associated with these eruptions may have been scavenged by ash particles, the atmospheric residence time of these volatiles would have been minimized. Therefore the eruptions probably had only a small effect on the composition of the Antarctic atmosphere and a negligible effect on local or global climate.

scholarly journals Techniques for analyses of trends in GRUAN data

2015 ◽  
Vol 8 (4) ◽  
pp. 1673-1684 ◽  
Author(s):  
G. E. Bodeker ◽  
S. Kremser
Keyword(s):  
Measurement Uncertainty ◽  
Trend Analysis ◽  
Global Climate ◽  
Regional Climate ◽  
Added Value ◽  
Least Squares Regression ◽  
Target Uncertainty ◽  
Reference Quality ◽  
Measurement Uncertainties

Abstract. The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) provides reference quality RS92 radiosonde measurements of temperature, pressure and humidity. A key attribute of reference quality measurements, and hence GRUAN data, is that each datum has a well characterized and traceable estimate of the measurement uncertainty. The long-term homogeneity of the measurement records, and their well characterized uncertainties, make these data suitable for reliably detecting changes in global and regional climate on decadal time scales. Considerable effort is invested in GRUAN operations to (i) describe and analyse all sources of measurement uncertainty to the extent possible, (ii) quantify and synthesize the contribution of each source of uncertainty to the total measurement uncertainty, and (iii) verify that the evaluated net uncertainty is within the required target uncertainty. However, if the climate science community is not sufficiently well informed on how to capitalize on this added value, the significant investment in estimating meaningful measurement uncertainties is largely wasted. This paper presents and discusses the techniques that will need to be employed to reliably quantify long-term trends in GRUAN data records. A pedagogical approach is taken whereby numerical recipes for key parts of the trend analysis process are explored. The paper discusses the construction of linear least squares regression models for trend analysis, boot-strapping approaches to determine uncertainties in trends, dealing with the combined effects of autocorrelation in the data and measurement uncertainties in calculating the uncertainty on trends, best practice for determining seasonality in trends, how to deal with co-linear basis functions, and interpreting derived trends. Synthetic data sets are used to demonstrate these concepts which are then applied to a first analysis of temperature trends in RS92 radiosonde upper air soundings at the GRUAN site at Lindenberg, Germany (52.21° N, 14.12° E).

Bristlecone pine tree rings and volcanic eruptions over the last 5000 yr

2007 ◽  
Vol 67 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Matthew W. Salzer ◽  
Malcolm K. Hughes
Keyword(s):  
Tree Ring ◽  
Ice Core ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Pine Tree ◽  
Tree Ring Data ◽  
Pinus Longaeva ◽  
Bristlecone Pine ◽  
Ice Core Record ◽  
Pinus Aristata

AbstractMany years of low growth identified in a western USA regional chronology of upper forest border bristlecone pine (Pinus longaeva and Pinus aristata) over the last 5000 yr coincide with known large explosive volcanic eruptions and/or ice core signals of past eruptions. Over the last millennium the agreement between the tree-ring data and volcano/ice-core data is high: years of ring-width minima can be matched with known volcanic eruptions or ice-core volcanic signals in 86% of cases. In previous millennia, while there is substantial concurrence, the agreement decreases with increasing antiquity. Many of the bristlecone pine ring-width minima occurred at the same time as ring-width minima in high latitude trees from northwestern Siberia and/or northern Finland over the past 4000–5000 yr, suggesting climatically-effective events of at least hemispheric scale. In contrast with the ice-core records, the agreement between widely separated tree-ring records does not decrease with increasing antiquity. These data suggest specific intervals when the climate system was or was not particularly sensitive enough to volcanic forcing to affect the trees, and they augment the ice core record in a number of ways: by providing confirmation from an alternative proxy record for volcanic signals, by suggesting alternative dates for eruptions, and by adding to the list of years when volcanic events of global significance were likely, including the mid-2nd-millennium BC eruption of Thera.

scholarly journals Simulating 195 Million Years of Global Climate in the Mesozoic

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Jack Lee
Keyword(s):  
Global Climate ◽  
Greenhouse Climate ◽  
Climate Simulations ◽  
Long Term Trends

An ensemble of climate simulations identifies factors that drove long-term trends of a prehistoric greenhouse climate.

scholarly journals A 3500-Year Ice Chemistry Record From The Dominion Range, Antarctica: Linkages Between Climatic Variations and Precipitation Chemistry

1990 ◽  
Vol 14 ◽  
pp. 358-358
Author(s):  
Mary Jo Spencer ◽  
Paul A. Mayewski ◽  
W. Berry Lyons ◽  
Mark S. Twickler ◽  
Pieter Grootes
Keyword(s):  
Oxygen Isotope ◽  
Global Climate ◽  
Ice Core ◽  
Precipitation Chemistry ◽  
Climate Forcing ◽  
Climatic Forcing ◽  
Climatic Variations ◽  
Oxygen Isotope Record ◽  
Isotope Record

In 1984 a 200-m ice core was collected from a local accumulation basin in the Dominion Range, Transantarctic Mountains, Antarctica. A complete oxygen isotope record has been obtained and a considerable portion of the core has been analyzed in detail for chloride, nitrate, sulfate, and sodium. About half of the chloride is due to sea salt with the remainder originating as gaseous HCl. Nitrate levels have increased markedly over the last 1000 years whereas the levels of the other constituents have remained fairly constant.The oxygen isotope results suggest that this region of Antarctica is responding to long-term global climate forcing as well as to shorter-term climatic variations. This data will be compared with the anion and sodium records in order to determine the effects of climatic forcing on these other records. In particular, nitrate appears to vary in concert with fluctuations in long-term climate. Additionally, variations in each constituent over the 3500 year period will be examined in detail to determine the influence of other processes which affect their concentrations.

scholarly journals Back to the Future: Using Long-Term Observational and Paleo-Proxy Reconstructions to Improve Model Projections of Antarctic Climate

Geosciences ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 255 ◽  
Author(s):  
Thomas J. Bracegirdle ◽  
Florence Colleoni ◽  
Nerilie J. Abram ◽  
Nancy A. N. Bertler ◽  
Daniel A. Dixon ◽  
...  
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Ice Core ◽  
Global Climate Models ◽  
Climate Projections ◽  
Past Performance ◽  
Wide Range ◽  
Proxy Reconstructions

Quantitative estimates of future Antarctic climate change are derived from numerical global climate models. Evaluation of the reliability of climate model projections involves many lines of evidence on past performance combined with knowledge of the processes that need to be represented. Routine model evaluation is mainly based on the modern observational period, which started with the establishment of a network of Antarctic weather stations in 1957/58. This period is too short to evaluate many fundamental aspects of the Antarctic and Southern Ocean climate system, such as decadal-to-century time-scale climate variability and trends. To help address this gap, we present a new evaluation of potential ways in which long-term observational and paleo-proxy reconstructions may be used, with a particular focus on improving projections. A wide range of data sources and time periods is included, ranging from ship observations of the early 20th century to ice core records spanning hundreds to hundreds of thousands of years to sediment records dating back 34 million years. We conclude that paleo-proxy records and long-term observational datasets are an underused resource in terms of strategies for improving Antarctic climate projections for the 21st century and beyond. We identify priorities and suggest next steps to addressing this.

scholarly journals Temporal and spatial analysis of ozone concentrations in Europe based on time scale decomposition and a multi-clustering approach

2019 ◽  
Author(s):  
Eirini Boleti ◽  
Christoph Hueglin ◽  
Stuart K. Grange ◽  
André S. H. Prévôt ◽  
Satoshi Takahama
Keyword(s):  
Time Scale ◽  
Seasonal Cycle ◽  
Clustering Algorithm ◽  
Short Term ◽  
Ozone Concentrations ◽  
Time Period ◽  
Term Variation ◽  
Long Term Trends ◽  
Time Scale Decomposition

Abstract. Air quality measures that were implemented in Europe in the 1990s resulted in reductions of ozone precursors concentrations. In this study, the effect of these reductions on ozone is investigated by analyzing surface measurements of ozone for the time period between 2000 and 2015. Using a non-parametric time scale decomposition methodology, the long-term, seasonal and short-term variation of ozone observations were extracted. A clustering algorithm was applied to the different time scale variations, leading to a classification of sites across Europe based on the temporal characteristics of ozone. The clustering based on the long-term variation resulted in a site type classification, while a regional classification was obtained based on the seasonal and short-term variations. Long-term trends of de-seasonalized mean and meteo-adjusted peak ozone concentrations were calculated across large parts of Europe for the time period 2000–2015. A multi-dimensional scheme was used for a detailed trend analysis, based on the identified clusters, which reflect precursor emissions and meteorological influence either on the inter-annual or the short-term time scale. Decreasing mean ozone concentrations at rural sites and increasing or stabilizing at urban sites were observed. At the same time downward trends for peak ozone concentrations were detected for all site types. The effect of hemispheric transport of ozone can be seen either in regions affected by synoptic patterns in the northern Atlantic or at sites located at remote high altitude locations. In addition, a reduction of the amplitude in the seasonal cycle of ozone was observed, and a shift in the occurrence of the seasonal maximum towards earlier time of the year. Finally, a reduced sensitivity of ozone to temperature was identified. It was concluded that long-term trends of mean and peak ozone concentrations are mostly controlled by precursors emissions changes, while seasonal cycle trends and changes in the sensitivity of ozone to temperature are driven by regional climatic conditions.

A Quantitative Holocene Climatic Record from Diatoms in Northern Fennoscandia

2000 ◽  
Vol 54 (2) ◽  
pp. 284-294 ◽  
Author(s):  
Atte Korhola ◽  
Jan Weckström ◽  
Lasse Holmström ◽  
Panu Erästö
Keyword(s):  
Regional Climate ◽  
Ice Core ◽  
Ice Age ◽  
Calibration Model ◽  
Subarctic Lakes ◽  
Northern Fennoscandia ◽  
Summer Temperatures ◽  
Climatic Record ◽  
Climate Events

A diatom-based calibration model for predicting summer temperatures was developed using climatically sensitive subarctic lakes in northern Fennoscandia. The model was applied to a sediment core from a treeline lake to infer trends in Holocene climate. The record exhibits long-term variations, as well as a series of shorter-term fluctuations on a time scale of centuries. Summers were warmest in the area about 6200 cal yr B.P. and featured distinct cooling episodes around 8300, 7200, 4200, 3000, and 400 cal yr B.P., most of these coinciding with some known climate events (e.g., the 8200 cal yr B.P. event and the Little Ice Age). The similarity of the observed shifts with the pacings of climate events from marine and ice-core records represents evidence for coupled ocean–atmosphere forcing of the regional climate.

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