Anthropogenic signals recorded in an ice core from Eclipse Icefield, Yukon Territory, Canada

Trends in the annual flux of sulfate and nitrate in a new ice core collected at an elevation of 3017 m on Eclipse Icefield, 45 km northeast of Mt. Logan were examined to determine the effect of anthropogenic activity on precipitation chemistry in the remote northwest North America mid-troposphere. The annual flux of both sulfate and nitrate at Eclipse began increasing in the 1940s, demonstrating, for the first time, the anthropogenic sulfate and nitrate pollution of the northwest North American Arctic in an ice core from this region. Comparison of the Eclipse record with regional emission estimates for total sulfur and nitrogen oxides suggests that Eurasia is the dominant source of pollutants reaching Eclipse. The available data does not permit a confident assessment of the relative importance of European versus Soviet emissions in producing the observed trends in sulfate and nitrate at Eclipse

The Determinants and Implications of Financial Asset Holdings of Non-Financial Firms in Turkey : An Emprical Investigation

This paper investigates the determinants and financial crowding out consequences of nonfinancial firms’ holdings of financial assets (FA) including government bonds and securities (GS) in Turkey using the firm level data compiled by the Central Bank of the Republic of Turkey over the 1990-2004 period. The salient features of the Turkish financial system with financial dollarisation and short maturity of financial contracts allowed the corporate sector to remain relatively liquid in spite of high inflation persisting until very recently. Consistent with the presence of capital market imperfections and financial adaptation, the Turkish corporate sector’s transactions-cum-precautionary motive-led holdings of the FA as a financial buffer are found to be relatively high and persistent. Contrasting with the transactions-cum-precautionary motive based “economies of scale” argument of the trade-off theory, but reflecting a plausible argument that financial constraints decrease and the ability to allocate resources into financial and real investments increases with firm size, the holdings of FA and GS tend to increase with the firm size both for manufacturing industry and other non-financial firms. The empirical results based on the one-step robust GMM estimations of DPD models suggest that the FA and GS holdings of the corporate sector can be explained by firm-specific characteristics including profitability, leverage ratios, asset tangibility and size along with macroeconomic condition variables represented by uncertainty and real interest rates on GS. The results further suggest that the impacts of these variables significantly vary not only across manufacturing industry and other non-financial firms but also between the large, medium and small sized firms. Under macroeconomic instability leading to excessively high real rate of returns for financial assets, non-financial firms tend to hold FA and GS also for their speculative motive. Consequently, financial assets and real investments may become substitutes rather than complements leading the former to crowd out the latter. The empirical results from a conventional accelerator model of investment augmented with variables representing firms financing conditions and PSBR strongly support such a financial crowding out impact of FA holdings for large sized manufacturing industry firms. For the small and medium sized firms, the positive complementary impact of precautionary and the negative substitution impact of speculative FA holdings are found to offset each other. Consistent with the credit view of the balance sheet literature, real investments of bank-dependent firms decline with an increase in the PSBR potentially due to the fact that government domestic debt is heavily financed via banks, which in turn deteriorates the credit availability for the corporate sector. This provides a further support to the “expansionary fiscal contractions” literature. The sensitivity of investment to cash flow is found to reflect the firms’ profitability and investment opportunities which are not fully conveyed by the fundamental Q rather than the degree of financial constraints. This paper also argues that the conventional pecking-order and trade-off theories of the capital structure literature may not be solely adequate in explaining the non-financial firms’ behaviour as financial intermediaries in Turkey. This might be the case also the acceleration of the FA holdings of firms in many industrial countries during the last decade in spite of declining financial constraints due to deepening international financial integration. An alternative but not mutually exclusive approach may be treating firms as facing a choice between allocating their resources into financial and real investments. The results of this paper provide a strong support to such an approach and suggest that financial investments may be a substitute or complementary to real investment depending respectively on whether the speculative or transactions-cum-precautionary motive dominates.Balance sheets, Cash flow, Corporate sector, Financial constraints, Financial crowding-out, Investment, Liquidity demand, Panel data, Turkey

A 100-year record of North Pacific volcanism in an ice core from Eclipse icefield, Yukon Territory, Canada

A record of regionally significant volcanic eruptions in the North Pacific over the last century has been developed using a glaciochemical record from Eclipse Icefield, Yukon Territory, Canada. Tephrochronology of the Eclipse ice core provides positive identification of the 1907 Ksudach, Kamchatka, the 1912 Katmai, Alaska, the 1947 Hekla, Iceland, and the 1989 Redoubt, Alaska, eruptions. Non-sea-salt SO42− residuals above a robust spline and empirical orthogonal function (EOF) analysis were used to identify volcanic SO42− signatures. Volcanic sulfate values are more conservatively identified by the EOF analysis as sulfate deposition from other sources is more robustly accounted for. Some eruptions are also recorded as peaks in non-sea-salt chloride. The volcanic signals in the Eclipse ice core are mostly attributable to Alaskan, Aleutian, or Kamchatkan eruptions. Conversely, the Eclipse ice core provides a poor record of globally significant tropical eruptions. These results are promising for the development of longer ice core based records of paleovolcanism in the North Pacific rim

Glaciochemical records from the Saint Elias Mountains, Yukon, Canada

While many paleoclimate records have been recovered from the North Atlantic sector of the Arctic, there is a gap in our understanding of climactic and environmental change in the North Pacific. Glaciochemical records from the St. Elias Mountains spanning an elevation range of three to five km provide a three-dimensional view of the paleo-atmosphere in this region. Three ice cores from Eclipse Icefield provide a high-resolution record of precipitation chemistry in the remote northwestern North America mid-troposphere and allow investigation of spatial and temporal variability in glaciochemical signals. Greater spatial variability is observed for species present as coarse mode dust and sea salt particles than for accumulation mode sulfate and ammonium aerosols or gas phase nitrate. Simultaneous sampling of aerosol and snow chemistry at King Col indicates large enrichments of nitrate and chloride in snow relative to aerosol by scavenging of gas phase nitric and hydrochloric acid. Back trajectories document the transport of Asian dust and anthropogenic emissions, the May 22 eruption plume of Sheveluch, Kamchatka, and sea salt from the Gulf of Alaska to King Col during the sampling period. The Eclipse ice cores provide a record of forest fire activity in Alaska and the Yukon that responds to anthropogenic influences such as the Klondike Gold Rush and natural climate variability such as the Medieval Warm Period. The Eclipse and Mt. Logan ice cores offer a record of regionally significant volcanic eruptions, with at least one-third of the eruptions recorded from Alaskan and Kamchatkan volcanoes. Major tropical eruptions are also recorded. The three Eclipse cores record similar volcanic sulfate fluxes from the largest eruptions such as Katmai, as well as some moderate eruptions. While a bipolar volcanic signal in 1809 is generally attributed to single tropical eruption, dacitic tephra from the Eclipse ice core that is chemically distinct from andesitic 1809 tephra found in Antarctica indicates a second eruption in the Northern Hemisphere at this time. Sulfate flux calculations suggest this eruption contributed little additional sulfate to circum-Arctic ice cores, and therefore had negligible climatic significance

Eclipse Ice Core Accumulation and Stable Isotope Variability as an Indicator of North Pacific Climate

The high accumulation rate and negligible amount of melt at Eclipse Icefield (3017 m) in the Saint Elias Range of Yukon, Canada, allows for the preservation of a high-resolution isotopic and glaciochemical records valuable for reconstruction of climatic variables. Each of the three Eclipse ice cores have a well-constrained depth–age scale with dozens of reference horizons over the twentieth century that permits an exceptional level of confi- dence in the results of the current calibration exercise. Stacked time series of accumulation and stable isotopes were divided into cold and warm seasons and seasons of extreme high and extreme low accumulation and stable isotope values (eight groups). For each group, season-averaged composites of 500-hPa geopotential height grids, and the individual seasons that constitute them, were analyzed to elucidate common anomalous flow patterns. This analysis shows that the most fractionated isotopes and lowest accumulation cold seasons reflect a more zonal height pattern in the North Pacific associated with negative Pacific–North American (PNA) and Pacific decadal oscillation (PDO) indices. Conversely, the least fractionated isotopes and highest accumulation cold seasons are associated with a positive PNA pattern. Although only a maximum of approximately 20% of the total number of accumulation and stable isotope seasons exhibit a relatively consistent relationship with 500-hPa geopotential height patterns, these results support the hypothesis that the most extreme accumulation and extreme isotope cold-season values in the Saint Elias Mountains are related to consistent atmospheric circulation and oceanic sea surface temperature patterns

Ice core paleovolcanic records from the St. Elias Mountains, Yukon, Canada

We previously reported a record of regionally significant volcanic eruptions in the North Pacific using an ice core from Eclipse Icefield (St. Elias Mountains, Yukon, Canada). The acquisition of two new ice cores from Eclipse Icefield, along with the previously available Eclipse Icefield and Mount Logan Northwest Col ice cores, allows us to extend our record of North Pacific volcanism to 550 years before present using a suite of four ice cores spanning an elevation range of 3–5 km. Comparison of volcanic sulfate flux records demonstrates that the results are highly reproducible, especially for the largest eruptions such as Katmai (A.D. 1912). Correlation of volcanic sulfate signals with historically documented eruptions indicates that at least one-third of the eruptions recorded in St. Elias ice cores are from Alaskan and Kamchatkan volcanoes. Although there are several moderately large (volcanic explosivity index (VEI) ≥ 4) eruptions recorded in only one core from Eclipse Icefield, the use of multiple cores provides signals in at least one core from all known VEI ≥ 4 eruptions in Alaska and Kamchatka since A.D. 1829. Tephrochronological evidence from the Eclipse ice cores documents eruptions in Alaska (Westdahl, Redoubt, Trident, and Katmai), Kamchatka (Avachinsky, Kliuchevoskoi, and Ksudach), and Iceland (Hekla). Several unidentified tephra-bearing horizons, with available geochemical evidence suggesting Alaskan and Kamchatkan sources, were also found. We present a reconstruction of annual volcanic sulfate loading for the North Pacific troposphere based on our ice core data, and we provide a detailed assessment of the atmospheric and climatic effects of the Katmai eruption

Ice core evidence for a second volcanic eruption around 1809 in the Northern Hemisphere

A volcanic signal observed in ice cores from both polar regions six years prior to Tambora is attributed to an unknown tropical eruption in 1809. Recovery of dacitic tephra from the 1809 horizon in a Yukon ice core (Eclipse) that is chemically distinct from andesitic 1809 tephra found in Antarctic ice cores indicates a second eruption in the Northern Hemisphere at this time. Together with the similar magnitude and timing of the 1809 volcanic signal in the Arctic and Antarctic, this could suggest a large tropical eruption produced the sulfate and Antarctic tephra and a minor Northern Hemisphere eruption produced the Eclipse tephra. Nonetheless, the possibility that there were coincidental eruptions of similar magnitude in both hemispheres, rather than a single tropical eruption, should not be discounted. Correctly attributing the source of the 1809 volcanic signal has important implications for modeling the magnitude and latitudinal distribution of volcanic radiative forcing

Corporate Sector Financial Structure in Turkey : A Descriptive Analysis

This paper presents and discusses some stylised facts of the corporate sector financial structure in Turkey using the Company Sector Accounts compiled by the Central Bank of the Republic of Turkey (CBRT). The findings of the paper suggest that non-financial firms in Turkey have been heavily exposed almost all of the basic balance sheet risks. The corporate sector appears to be excessively leveraged with relatively lower asset tangibility creating also a credit risk for the lenders. The firms rely heavily on foreign currency denominated and short-term debt instruments making them vulnerable to both exchange rate and interest rate shocks through currency and maturity mismatches. The corporate sector can be characterised as financially constrained as the deepening of the Turkish bank-based financial system is rather low and the bank credits to the private sector tend to be crowded out by the mode of domestic debt finance. The corporate sector vulnerabilities to maturity, interest rate and currency risks are found to be improving with the firm size. With the relatively stable macroeconomic environment and stricter prudential regulation on the financial system, the corporate sector balance sheet risks, albeit still are at high levels, tend to be improving after the financial crisis of 2001.Balance sheets, Capital structure, Corporate sector, Debt composition, Financial crowding-out, Liability dollarisation, Turkey

Constraining recent lead pollution sources in the North Pacific using ice core stable lead isotopes

Trends and sources of lead (Pb) aerosol pollution in the North Pacific rim of North America from 1850 to 2001 are investigated using a high-resolution (subannual to annual) ice core record recovered from Eclipse Icefield (3017 masl; St. Elias Mountains, Canada). Beginning in the early 1940s, increasing Pb concentration at Eclipse Icefield occurs coevally with anthropogenic Pb deposition in central Greenland, suggesting that North American Pb pollution may have been in part or wholly responsible in both regions. Isotopic ratios (208Pb/207Pb and 206Pb/207Pb) from 1970 to 2001 confirm that a portion of the Pb deposited at Eclipse Icefield is anthropogenic, and that it represents a variable mixture of East Asian (Chinese and Japanese) emissions transported eastward across the Pacific Ocean and a North American component resulting from transient meridional atmospheric flow. Based on comparison with source material Pb isotope ratios, Chinese and North American coal combustion have likely been the primary sources of Eclipse Icefield Pb over the 1970–2001 time period. The Eclipse Icefield Pb isotope composition also implies that the North Pacific mid-troposphere is not directly impacted by transpolar atmospheric flow from Europe. Annually averaged Pb concentrations in the Eclipse Icefield ice core record show no long-term trend during 1970–2001; however, increasing 208Pb/207Pb and decreasing 206Pb/207Pb ratios reflect the progressive East Asian industrialization and increase in Asian pollutant outflow. The post-1970 decrease in North American Pb emissions is likely necessary to explain the Eclipse Icefield Pb concentration time series. When compared with low (lichen) and high (Mt. Logan ice core) elevation Pb data, the Eclipse ice core record suggests a gradual increase in pollutant deposition and stronger trans-Pacific Asian contribution with rising elevation in the mountains of the North Pacific rim

Ice Core Paleovolcanic Records from the St. Elias Mountains, Yukon, Canada

We previously reported a record of regionally significant volcanic eruptions in the North Pacific using an ice core from Eclipse Icefield (St. Elias Mountains, Yukon, Canada). The acquisition of two new ice cores from Eclipse Icefield, along with the previously available Eclipse Icefield and Mount Logan Northwest Col ice cores, allows us to extend our record of North Pacific volcanism to 550 years before present using a suite of four ice cores spanning an elevation range of 3 - 5 km. Comparison of volcanic sulfate flux records demonstrates that the results are highly reproducible, especially for the largest eruptions such as Katmai ( A. D. 1912). Correlation of volcanic sulfate signals with historically documented eruptions indicates that at least one-third of the eruptions recorded in St. Elias ice cores are from Alaskan and Kamchatkan volcanoes. Although there are several moderately large ( volcanic explosivity index (VEI) \u3e= 4) eruptions recorded in only one core from Eclipse Icefield, the use of multiple cores provides signals in at least one core from all known VEI \u3e= 4 eruptions in Alaska and Kamchatka since A. D. 1829. Tephrochronological evidence from the Eclipse ice cores documents eruptions in Alaska (Westdahl, Redoubt, Trident, and Katmai), Kamchatka (Avachinsky, Kliuchevoskoi, and Ksudach), and Iceland (Hekla). Several unidentified tephra-bearing horizons, with available geochemical evidence suggesting Alaskan and Kamchatkan sources, were also found. We present a reconstruction of annual volcanic sulfate loading for the North Pacific troposphere based on our ice core data, and we provide a detailed assessment of the atmospheric and climatic effects of the Katmai eruption