Atmospheric Ozone And Its Biosphere - Atmosphere Exchange In A Mangrove Forest Ecosystem A Case Study From Sundarbans NE Coast Of India

ABSTRACT Temporal variation of atmospheric O3 and its biosphere atmosphere exchange were monitored in the Sundarbans mangrove forest from January 2011 to December 2011 on bimonthly basis. O3 mixing ratios at 10 m and 20 m heights over the forest atmosphere ranged between 14.66 1.88 to 37.90 0.91 and 19.32 6.27 to 39.80 10.13 ppbv respectively having maximal premonsoon and minimal monsoon periods. Average daytime O3 mixing ratio was 1.69 times higher than nighttime indicates significant photo chemical production of O3 in forest atmosphere. Annual averaged O3 mixing ratio in 10 m height was 13.2 lower than 20 m height induces exchange of O3 across mangrove biosphere atmosphere interface depending upon micrometeorological conditions of the forest ecosystem. Annual average biosphere atmosphere O3 exchange flux in this mangrove forest environment was 0.441 g m-2 s-1. Extrapolating the value for entire forest surface area the mangrove ecosystem acts as a sink of 58.4GgO3 annually indicating significant contribution of Sundarbans mangroves towards regional atmospheric O3 budget as well as climate change.