Measurements of J < inf> NO3 < sup> - in snow by nitrate-based actinometry

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Conference Proceeding

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Chemical actinometry was used to measure nitrate photolysis rate coefficients, JNO3-, on and in snowpack at Summit, Greenland. Sealed glass tubes containing nitrate and a hydroxyl radical trapping system were buried in snow and exposed for between 2 and 24h. Average JNO3- values for 2-h midday exposures in early June on surface snow were 10-14×10-7s-1. Averages over 24h were 3.5-4.5×10-7s-1. These values reflect the integrated photon flux and also any variation of the nitrate photolysis rate with temperature. Attenuation of JNO3- within the firn was 0.03-0.04cm-1 for 24-h exposures and 0.08cm-1 for a 2-h exposure. Different attenuation coefficients may relate to differential light penetration due to changes in sun angle over the course of 24h. © 2002 Elsevier Science Ltd. All rights reserved.

Publication Title

Atmospheric Environment