Measurements of trace substances in the Arctic troposphere as potential precursors and constituents of Arctic haze

• Published in: Journal of atmospheric chemistry 1999-11, Vol.34 (3), p.291-319
• Main Authors: JAESCHKE, W, SALKOWSKI, T, DIERSSEN, J. P, TRÜMBACH, J. V, KRISCHKE, U, GÜNTHER, A
• Format: Article
• Language: English
• Subjects: Altitude; Ammonium; Chemical composition and interactions. Ionic interactions and processes; Earth, ocean, space; Emission measurements; Exact sciences and technology; External geophysics; Measurement techniques; Meteorology; Nitrates; Nitric acid; Ozone; Spring; Stratosphere; Sulfates; Sulfur; Sulfur dioxide; Summer; Trace elements; Troposphere
• ISSN: 0167-7764; 1573-0662
• DOI: 10.1023/A:1006277230042

During two measuring campaigns in early spring 1994 and 1995 (March/April) and one campaign in summer 1994, measurements of ozone, PAN, sulfur dioxide, nitric acid, and particulate nitrate, sulfate, and ammonium (only 1995) were recorded in the Arctic. Observations were made by aircraft at various sites in the eastern and western Arctic. Ozone concentrations showed a steady increase with altitude both in spring and summer. During five flights in springtime, low ozone events (LOEs) could be observed near the surface and up to altitudes of 2000 m. SO^sub 2^ background concentrations, ranging from detection limit (0.5 nmol/m^sup 3^) to 5 nmol/m^sup 3^, were observed during both spring and summer. Distinct maxima up to 55 nmol/m^sup 3^ in lower altitudes were only obtained in springtime. Concentrations of the organic nitrate PAN were within a similar range as those of the inorganic nitrate HNO^sub 3^ during spring campaigns. In contrast, concentrations of particulate nitrate were one half an order of magnitude lower. HNO^sub 3^ concentrations increased significantly with altitude. Evidently, HNO^sub 3^ was intruded from the stratosphere into the troposphere. Sulfate concentrations ranged between 5 and 30 nmol/m^sup 3^; ammonium concentrations were obtained within a range from 10 to 50 nmol/m^sup 3^.[PUBLICATION ABSTRACT]