UK Environmental Change Network (ECN) atmospheric nitrogen chemistry data: 1993-2012 - Rennie, S.; Adamson, J.; Anderson, R.; Andrews, C.; Bater, J.; Bayfield, N.; Beaton, K.; Beaumont, D.; Benham, S.; Bowmaker, V.; Britt, C.; Brooker, R.; et al. (NERC Environmental Information Data Centre, 2015)