First measurements of total chlorine and bromine in the lower stratosphere

Berg, Walter W.; Crutzen, Paul J.; Grahek, F. E.; Gitlin, Sonia N.; Sedlacek, W. A.

doi:10.1029/gl007i011p00937

Cited by 52 publications

(26 citation statements)

References 18 publications

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“…The increase in the ratio also is not consistent with fly ash from the power plant located next to the proposed ILAW Disposal Site. Leaching of an 1l-cm-deep sample of fly ash yielded a C1/Br ratio of 41 (Table E.3, Appendix E), somewhat lower than the meteoric signature of 80 reported by Berg et al (1980). In contrast to the shallow fly ash sample, a deeper sample (61 cm) yielded a CM3r ratio of 382.…”

Section: B422mentioning

confidence: 62%

“…They suggested that C1/Br ratios in precipitation vary geographically between 130 and 180 near the coast, to between 75 and 120 several tens to a few hundred kilometers inland, to as low as 50 several hundred kilometers inland. Berg et al (1980) measured a C1/Br ratio of 80 in the lower stratosphere at northern latitudes, which represents the total concentration of these anions in air. In the absence of specific measurements of meteoric C1/Br in the Pasco Basin, shallow porewater ratios should reflect the combined wetidry fallout ratio of meteoric CM%.…”

Section: B422mentioning

confidence: 99%

See 1 more Smart Citation

Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment

Fayer¹,

Murphy²,

Downs³

et al. 1999

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Section: B422mentioning

confidence: 62%

Section: B422mentioning

confidence: 99%

Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment

Fayer¹,

Murphy²,

Downs³

et al. 1999

View full text Add to dashboard Cite

“…The increase in the ratio also is not consistent with fly ash from the power plant located next to the proposed ILAW Disposal Site. Leaching of an 11-cm-deep sample of fly ash yielded a Cl/Br ratio of 41 (Table E.3, Appendix E), somewhat lower than the meteoric signature of 80 reported by Berg et al (1980). In contrast to the shallow fly ash sample, a deeper sample (61 cm) yielded a Cl/Br ratio of 382.…”

Section: B423 Cl/br Ratiosmentioning

confidence: 58%

“…They suggested that Cl/Br ratios in precipitation vary geographically between 130 and 180 near the coast, to between 75 and 120 several tens to a few hundred kilometers inland, to as low as 50 several hundred kilometers inland. Berg et al (1980) measured a Cl/Br ratio of 80 in the lower stratosphere at northern latitudes, which represents the total concentration of these anions in air. In the absence of specific measurements of meteoric Cl/Br in the Pasco Basin, shallow porewater ratios should reflect the combined wet/dry fallout ratio of meteoric Cl/Br.…”

Section: B423 Cl/br Ratiosmentioning

confidence: 99%

Performance Assessment

1999

International Oil Spill Conference Proceedings

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SummaryLockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are currently stored in single -and double -shell tanks at the Hanford Site. The preferred method of disposing of the portion that is classified as immobilized lowactivity waste (ILAW) is to vitrify the waste and place the product in near-surface, shallow-land burial facilities. The LMHC project to assess the performance of these disposal facilities is known as the Hanford ILAW Performance Assessment (PA) Activity, hereafter called the ILAW PA project. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require predictions of contaminant migration from the facility. To make such predictions will require estimates of the fluxes of water moving through the sediments within the vadose zone around and beneath the disposal facility. These fluxes, loosely called recharge rates, are the primary mechanism for transporting contaminants to the groundwater.Pacific Northwest National Laboratory (PNNL) assists LMHC in their performance assessment activities. One of the PNNL tasks is to provide estimates of recharge rates for current conditions and long-term scenarios involving the shallow-land disposal of ILAW. Specifically, recharge estimates are needed for a fully functional surface cover, the cover sideslope, and the immediately surrounding terrain. In addition, recharge estimates are needed for degraded cover conditions. The temporal scope of the analysis is 10,000 years, but could be longer if some contaminant peaks occur after 10,000 years.The elements of this report compose the Recharge Data Package, which provides estimates of recharge rates for the scenarios being considered in the 2001 PA. Table S.1 identifies the surface features and time periods evaluated. The most important feature, the surface cover, is expected to be the modified RCRA Subtitle C design. This design uses a 1-m-thick silt loam layer above sand and gravel filter layers to create a capillary break. A 0.15-m-thick asphalt layer underlies the filter layers to function as a backup barrier and to promote lateral drainage. Cover sideslopes are expected to be constructed with 1V:10H slopes using sandy gravel. The recharge estimates for each scenario were derived from lysimeter and tracer data collected by the ILAW PA and other projects and from modeling analyses.For the best estimate case, we proposed using a recharge rate of 0.1 mm/yr for the surface cover with a shrub-steppe plant community. This rate is lower than the cover design goal of 0.5 mm/yr because it is closer to the actual drainage rate measured with lysimeters and inferred with modeling. The simulation results showed that erosion of 20% of the silt loam layer did not impair this performance nor did the deposition of 20 cm of dune sand. For the sandy grav...

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“…Furthermore, the mixing ratios of all these gases were found to decrease with altitude, corroborating the hypothesis of photochemical decomposition in the stratosphere. Total chlorine measurements by a collection system were made by Berg et al (1980). These in situ measurements were later complemented by remotely sensed profiles.…”

Section: Corroboration and Falsification: Stratospheric Trace Gas Meamentioning

confidence: 99%

Chlorine in the stratosphere

Clarmann¹

2013

Atmósfera

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Este artículo reseña varios aspectos de los compuestos clorados presentes en la estratosfera, que incluyen tanto su papel como agentes químicos como su función de trazadores de los procesos dinámicos. En la estratosfera, el cloro reactivo se libera a partir de los clorofluorocarbonos y otros gases orgánicos que contienen cloro. La mayor parte del cloro reactivo se convierte en compuestos inertes que almacenan cloro, como ClONO 2 y HCl. La reactivación del cloro estratosférico ocurre principalmente por reacciones heterogéneas en vórtices polares invernales, en combinación con la luz solar. Los ciclos catalíticos de Cl, ClO, BrO, Cl 2 O 2 , ClO 2 y otros compuestos como NO, NO 2 , OH y HO 2 destruyen el oxígeno impar (ozono y oxígeno atómico) de la atmósfera. El ciclo del dímero de ClO es particularmente importante en la formación del agujero de ozono, mientras que en latitudes medias el HOCl tiene alguna relevancia. También los eventos de protones solares pueden alterar la química del cloro estratosférico, aunque su efecto de activación o desactivación depende de las condiciones de iluminación. La vida media atmosférica de los clorofluorocarbonos determina la disponibilidad de las sustancias que destruyen el ozono en la estratosfera y depende de la circulación de Brewer-Dobson, que a su vez establece a qué altitudes y por cuánto tiempo está expuesta una porción de aire a la fotoquímica. Por su parte, los gases orgánicos clorados pueden usarse como trazadores para estimar la edad del aire estratosférico y así examinar la circulación de Brewer-Dobson. El uso de métodos complementarios de medición ha sido esencial para ampliar nuestros conocimientos sobre los compuestos clorados en la estratosfera. El ClO se mide principalmente con métodos de percepción remota en las regiones del infrarrojo y de microondas. Las bandas del infrarrojo lejano son ideales para medir el HOCl, pero también se encuentra información sustancial en las regiones de microondas y del infrarrojo medio. El ClONO 2 se mide sólo en el infrarrojo térmico, en tanto que el HCl se puede observar en las regiones de microondas y del infrarrojo lejano y medio. Sin embargo, las bandas del HCl en el infrarrojo medio se encuentran en longitudes de onda en que la radiación de cuerpo negro a temperaturas terrestres es tan baja que el HCl sólo se puede detectar mediante la técnica de absorción solar. Los clorofluorocarbonos se miden con mayor exactitud utilizando métodos de muestreo in situ, aunque para lograr una cobertura global se requieren mediciones en el infrarrojo térmico realizadas desde satélites. En términos epistemológicos, la investigación de la química de la estratosfera y el papel específico de los compuestos clorados se ha basado en distintos conceptos científicos como el razonamiento deductivo, el falsacionismo, el razonamiento abductivo y la llamada "solución de enigmas dentro de la ciencia normal". Sin embargo, la concepción estructuralista de la visión no enunciativa de las teorías es probablemente la que mejor se aplica a la investigación de ...

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First measurements of total chlorine and bromine in the lower stratosphere

Cited by 52 publications

References 18 publications

Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment

Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment

Performance Assessment

Chlorine in the stratosphere

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