edu.ucar.opensky::articles:12046 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T04:07:11.231042 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7xs5w3f Nitrous acid (HONO) during polar spring in Barrow, Alaska: A net source of OH radicals? 2011-12-23T00:00:00Z publication https://n2t.org/ark:/85065/d7xs5w3f https://doi.org/10.1029/2011JD016643 Villena, G. author Wiesen, P. author Cantrell, Chris A. author Flocke, Frank M. author Fried, Alan author Hall, Samuel R. author Hornbrook, Rebecca author Knapp, David author Kosciuch, Edward author Mauldin, Roy author McGrath, Joshua author Montzka, Denise D. author Richter, David author Ullmann, Kirk author Walega, James G. author Weibring, Petter author Weinheimer, Andrew author Staebler, R. author Liao, J. author Huey, L. author Kleffmann, J. author UCAR/NCAR - Library publisher HONO was measured by a LOPAP instrument (LOng Path Absorption Photometer) for one month during the OASIS spring 2009 campaign in Barrow, Alaska. HONO concentrations between ≤ 0.4 pptv (DL) and ∼500 pptv were measured. The very high concentrations observed on several days were caused by local direct emissions and were highly correlated with the NOx and CO data. When only "clean days" were considered, average HONO concentrations varied between ≤ 0.4 - 10 pptv. Average HONO/NOx and HONO/NOy ratios of ∼6% and ∼1% were observed, respectively, in good agreement with other remote LOPAP measurement data, but lower than measured in most other polar regions by other methods. The strong correlation between sharp peaks of OH and HONO during daytime, which was not observed for any other measured radical precursor, suggested that HONO photolysis was a major source of OH radicals in Barrow. This was supported by calculated net OH radical production by HONO and O₃ photolysis for which the contribution of O₃ (2%) could be neglected compared to that of HONO (98%). A net extra HONO/OH source necessary to explain elevated HONO levels during daytime of up to 90 pptv/h was determined, which was highly correlated with the actinic flux. Accordingly, a photochemical HONO source is proposed here, in good agreement with recent studies. From the higher correlation of the net HONO source with JNO₂ and [NO₂] compared to Jα(₁D) and [NO³-], photosensitized conversion of NO2 on humic acid containing snow surfaces may be a more likely source of HONO in the polar atmosphere of Barrow than nitrate photolysis. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2011 American Geophysical Union. None eng geoscientificInformation