Observations of iodine oxide in the Indian Ocean marine boundary layer: A transect from the tropics to the high latitudes

TY - JOUR

T1 - Observations of iodine oxide in the Indian Ocean marine boundary layer

T2 - A transect from the tropics to the high latitudes

AU - Mahajan, Anoop S.

AU - Tinel, Liselotte

AU - Hulswar, Shrivardhan

AU - Cuevas, Carlos A.

AU - Wang, Shanshan

AU - Ghude, Sachin

AU - Naik, Ravidas K.

AU - Mishra, Rajani K.

AU - Sabu, P.

AU - Sarkar, Amit

AU - Anilkumar, N.

AU - Saiz Lopez, Alfonso

N1 - 2019 The Author(s). Published by Elsevier Ltd.

PY - 2019/1/29

Y1 - 2019/1/29

N2 - Observations of iodine oxide (IO) were made in the Indian Ocean and the Southern Ocean marine boundary layer (MBL) during the 8th Indian Southern Ocean Expedition. IO was observed almost ubiquitously in the open ocean with larger mixing ratios south of the Polar Front (PF). Contrary to previous reports, IO was not positively correlated to sea surface temperature (SST)/salinity, or negatively to chlorophyll a. Over the whole expedition, SST showed a weak negative correlation with respect to IO while chl a was positively correlated. North of the PF, chl a showed a strong positive correlation with IO. The computed HOI and I2 fluxes do not show any significant correlation with atmospheric IO. Simulations with the global CAM-Chem model show a reasonably good agreement with observations north of the PF but the model fails to reproduce the elevated IO south of the PF indicating that the current emission parametrizations are not sufficient to explain iodine chemistry in the Southern Indian Ocean.

AB - Observations of iodine oxide (IO) were made in the Indian Ocean and the Southern Ocean marine boundary layer (MBL) during the 8th Indian Southern Ocean Expedition. IO was observed almost ubiquitously in the open ocean with larger mixing ratios south of the Polar Front (PF). Contrary to previous reports, IO was not positively correlated to sea surface temperature (SST)/salinity, or negatively to chlorophyll a. Over the whole expedition, SST showed a weak negative correlation with respect to IO while chl a was positively correlated. North of the PF, chl a showed a strong positive correlation with IO. The computed HOI and I2 fluxes do not show any significant correlation with atmospheric IO. Simulations with the global CAM-Chem model show a reasonably good agreement with observations north of the PF but the model fails to reproduce the elevated IO south of the PF indicating that the current emission parametrizations are not sufficient to explain iodine chemistry in the Southern Indian Ocean.

KW - Halogens

KW - Indian ocean

KW - Iodine

KW - Marine boundary layer

KW - Ozone

UR - http://www.scopus.com/inward/record.url?scp=85060847634&partnerID=8YFLogxK

U2 - 10.1016/j.aeaoa.2019.100016

DO - 10.1016/j.aeaoa.2019.100016

M3 - Article

AN - SCOPUS:85060847634

SN - 2590-1621

VL - 1

SP - 1

EP - 10

JO - Atmospheric Environment: X

JF - Atmospheric Environment: X

M1 - 100016

ER -