Far infrared measurement of the solar minimum temperature     

John A. Eddy  Pierre J. Léna  Robert M. MacQueen 《Solar physics》1969,10(2):330-341

Radiometric measurement of the brightness temperature of the mean solar disk has been made in the wavelength range from 238 to 312 (42.1 cm^-1 to 32.1 cm^-1), using a Michelson interferometer of resolution 0.25 cm^-1, carried on the NASA research aircraft at altitude 12.6 km. A mean temperature 4370 ± 260 K is obtained. The result is compared with other measurements of the solar minimum temperature and with the prediction of the BCA Model.The National Center for Atmospheric Research is sponsored by the National Science Foundation.  相似文献   

Stable isotope geochemistry of magnesite from Holocene salt lake deposits,Taoudenni, Mali     

Florias Mees  Eddy Keppens 《Geological Journal》2013,48(6):620-627

Stable isotope data (δ¹⁸O, δ¹³C) were obtained for magnesite (MgCO₃) from Holocene salt lake deposits of the Taoudenni–Agorgott basin, Mali, in which it is the only carbonate mineral present. The deposits have a high glauberite content (Na₂Ca(SO₄)₂), representing a type of continental evaporite formation that is commonly magnesite‐bearing. Samples from seven different levels in a 5 m long sequence were analysed. δ¹⁸O_V‐PDB values are between +3.17 and +5.91‰, which is lower than might be expected for evaporitic environments, recording reduced ¹⁸O enrichment at high salinity. δ¹³C_V‐PDB values are between −1.32‰ and −4.79‰, showing an influence of carbon derived from the decomposition of organic matter rather than from exchange with atmospheric CO₂. Covariance between δ¹⁸O and δ¹³C is strong for the lower part of the sequence, recording coupled ¹⁸O and ¹³C enrichment as commonly observed for closed basins. Covariance is lacking for the upper part of the sequence, with only periodic massive magnesite deposition in a more shallow lake. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献