Seasonal variation of volatile organic iodine compounds in the water column of Funka Bay, Hokkaido, Japan

Autor: Hiroji Onishi, Kota Suzuki, Naoto Kobayashi, Seiji Tanaka, Yuta Inagaki, Yoshihiko Kamei, Atsushi Ooki, Kenshi Kuma, Yusaku Shimizu, Tetsuya Takatsu
Rok vydání: 2016
Předmět:
Zdroj: Journal of Atmospheric Chemistry. 74:205-225
ISSN: 1573-0662
0167-7764
Popis: Volatile organic iodine compounds (VOIs) emitted from the ocean surface to the air play an important role in atmospheric chemistry. Shipboard observations were conducted in Funka Bay, Hokkaido, Japan, bimonthly or monthly from March 2012 to December 2014, to elucidate the seasonal variations of VOI concentrations in seawater and their sea-to-air iodine fluxes. The bay water exchanges with the open ocean water of the North Pacific twice a year (early spring and autumn). Vertical profiles of CH2I2, CH2ClI, CH3I, and C2H5I concentrations in the bay water were measured bimonthly or monthly within an identified water mass. The VOI concentrations began to increase after early April at the end of the diatom spring bloom, and represented substantial peaks in June or July. The temporal variation of the C2H5I profile, which showed a distinct peak in the bottom layer from April to July, was similar to the PO4 3− variation profile. Correlation between C2H5I and PO4 3− concentrations (r = 0.93) suggests that C2H5I production was associated with degradation of organic matter deposited on the bottom after the spring bloom. CH2I2 and CH2ClI concentrations increased substantially in the surface and subsurface layers (0–60 m) in June or July resulted in a clear seasonal variation of the sea-to-air iodine flux of the VOIs (high in summer or autumn and low in spring).
Databáze: OpenAIRE
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