A comparison of tritium and strontium-90 fallout in the Southern Hemisphere

Taylor, C.B.

doi:10.1111/j.2153-3490.1968.tb00400.x

Cited by 29 publications

(12 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The • radioactivity measurements. The values of artificial • activity in Antarctic snow are characterized by two well-defined reference levels, one, previously mentioned, at the beginning of 1955 [Picciotto and Wilgain, 1963] This seasonal pattern, connected to the stratospheric-tropospheric exchange mechanisms, has been observed in southern hemisphere precipitation [Taylor, 1968] and in the South Pole • profile, providing additional information concerning the snow deposition chronology at this station ].…”

Section: Period From 1955 To 1975mentioning

confidence: 81%

A detailed study of snow accumulation and stable isotope content in Dome C (Antarctica)

Petit¹,

Jouzel²,

Pourchet³

et al. 1982

J. Geophys. Res.

115

View full text Add to dashboard Cite

Snow samples have been taken in the Dome C area in order to study the variations of the accumulation rate and of the stable isotope content over the last century. Stake observations indicate a large spatial variability of the accumulation rate at a 1‐year scale (σs = 2.6 g cm−2 yr−1 for a mean value ā = 3.6 g cm−2 yr−1). The depth of the 1965 and 1955 layers determined from beta radioactivity measurements in 19 sites lets us deduce that the spatial variability becomes small at a 10‐year scale (σs = 0.3 g cm−2 yr−1), showing that the snow collected at one point is well representative of the fallen precipitation over this period. The rate of snow accumulation since 1965 is about 30% higher than during the 1955–1965 period. This conclusion is supported by measurements over a large geographical sector of East Antarctica. Shorter‐term changes of the snow accumulation have been studied by various means and in particular from detailed deuterium content profiles; by comparing with the beta and tritium radioactivity determinations it is shown that the deuterium variations do not allow us to obtain a seasonal record. In such a low‐accumulation area, different mechanisms (such as smoothing of the isotopic signal, roughness of the surface, irregularity of the accumulation) which may disturb the short‐term record are discussed. The interpretation of stratigraphie observations is not straightforward. However, it was possible to obtain a calibration down to the 1955 layer, which allows us to offer a dating of the snow layers over the last century. The mean accumulation so obtained (3.7 g cm−2 yr−1) is in good agreement with the value (3.6±0.5) deduced from lead 210 measurements. Geographical changes of the mean deuterium content are relatively small, showing that at a 10‐year scale the isotopic signal is well representative of the mean deuterium content of the precipitation. This ensures that the smoothed (10‐year running mean values) deuterium profile obtained over the last 160 years provides a good indication of the temperature secular trend in the Dome C area.

show abstract

Section: Period From 1955 To 1975mentioning

confidence: 81%

A detailed study of snow accumulation and stable isotope content in Dome C (Antarctica)

Petit¹,

Jouzel²,

Pourchet³

et al. 1982

J. Geophys. Res.

115

View full text Add to dashboard Cite

show abstract

“…Marine organisms produce gaseous sulfur-bearing compounds which are oxidized over the oceans first into SO2 2. Most of the excess sulfate would be subsiding from the stratospheric reservoir, which is known to exchange with the low atmosphere at the beginning of summer [Taylor, 1968]. This assumption which has been discussed by Shaw [1979] and by Delmas and Boutton [1980] for the Antarctic Plateau, seems to be unlikely in coastal areas where the snow accumulation is high (see the discussion of the possible stratospheric volcanic contribution below).…”

Section: Secondary Aerosolmentioning

confidence: 97%

Snow chemistry on James Ross Island (Antarctic Peninsula)

Aristarain¹,

Delmas²,

Briat³

1982

J. Geophys. Res.

View full text Add to dashboard Cite

More than 400 firn samples were collected at an altitude of 1660 m on the small ice sheet covering James Ross Island (northeastern coast of the Antarctic Peninsula). Chemical analysis of these samples provides information about the marine background aerosol composition in the area. The samples cover the years 1975–1979 (pit samples) and the last 15 years (firn core samples). Major impurities (Na, K, Ca, Al, H, SO4, and NO3) were determined by using flameless atomic absorption, neutron activation, acid titration, or ion chromatography. Aerosols are contributed mainly by the surrounding ocean; however, secondary aerosol deposition (H2SO4 and HNO3) is also important. All samples were found to be slightly acidic (pH generally in the range 5–6). Strong seasonal variations (maximum values in summer) are found in the H2SO4 deposition. A photochemical mechanism is proposed to explain the local production of H2SO4 from gaseous marine sulfur compounds. From these results, a yearly deposition of ∼0.13 Tg of H2SO4 is calculated for the entire Antarctic continent.

show abstract

“…Almost all of the bomb tritium has been injected into the stratosphere of the northern hemisphere. The exchange time between the northern and the southern stratosphere is several years [Taylor, 1966[Taylor, , 1968. The typical time scale for mixing tropospheric air masses across the equator is about 1 year [Jacob et al, 1987;Prather et al, 1987].…”

Section: Transient Tracer Backgroundmentioning

confidence: 99%