Atmospheric Chemistry Division, National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA

The Institute for Integrative and Multidisciplinary Earth Studies (TIIMES), National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA

Dept. of Civil and Environmental Engineering, Washington State University, Pullman, WA, USA

Atmospheric Chemistry Division, National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA

The Institute for Integrative and Multidisciplinary Earth Studies (TIIMES), National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA

Dept. of Civil and Environmental Engineering, Washington State University, Pullman, WA, USA

Center for Ecology and Hydrology (CEH), Edinburgh, UK

Dept. of Civil and Environmental Engineering, Washington State University, Pullman, WA, USA

Earth Observing Laboratory, National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA

The Institute for Integrative and Multidisciplinary Earth Studies (TIIMES), National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA

Atmospheric Chemistry Division, National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA

The Institute for Integrative and Multidisciplinary Earth Studies (TIIMES), National Center for Atmospheric Research, P.O. Box 3000 Boulder, CO 80307, USA