Modeling the formation of tropical rings of atomic bromine and iodine

ALFONSO SAIZ-LOPEZ; RAFAEL PEDRO FERNÁNDEZ; JUAN CARLOS GOMEZ MARTIN; ROSS SALAWITCH; DOUGLAS E. KINNISON; JEAN-FRANCOISE LAMARQUE; SIMONE TILMES

Viena

Conferencia; European Geosciences Union General Assembly (EGU-2015); 2015

European Geosciences Union

p { margin-bottom: 0.1in; line-height: 120%; }Very short-lived(VSL) bromo- and iodocarbons are produced at a prodigious rate byocean biology and these source compounds (SGVSL), togetherwith their degradation inorganic products (PGVSL), arelofted by vigorous convection to the tropical tropopause layer (TTL).Using a state-of-the-art photochemical mechanism within a globalmodel, we investigate the partitioning and loading of reactiveinorganic halogens within the TTL. The specific low ozone and lowtemperature conditions of this region of the atmosphere changes thesteady-state between halogen atoms and oxides, making the atoms thedominant species. We suggest that this leads to the formation of twodaytime ?tropical rings? of both atomic bromine and iodine thatcircle the tropics with the sun. In addition to a description of thisphotochemical phenomenon, this communication the partitioning ofinorganic halogen reservoirs within the TTL and assess its relevancefor the injection of bromine to stratosphere.