AIRBORNE OBSERVATIONS OF STRONG BIOGENIC NOX EMISSIONS FROM THE NAMIBIAN SAVANNA AT THE END OF THE DRY SEASON

We report the observation of substantial emissions of NOx from a sever al-hundred-square-kilometer region of savanna in northern Namibia in S eptember 1992. The estimated emission rates lie near the high end of t he range of values reported from flux chamber studies on various tropi cal savanna sails and appear to be associated with a light rainfall ev ent which occurred 4 days prior to the observations. If our measuremen ts are typical for this situation, then biogenic emission of NOx follo wing sporadic rainfall events during and at the end of the dry season may be an important regional source rivaling that arising from savanna burning and may have important consequences for regional scale ozone formation.