Biogenic volatile organic compound (BVOC) emission estimation dates back to the 1950s with the estimates of Dr. Fritz Went of global BVOC emissions into the atmosphere of at least 100 million tons of monoterpenes. Soon after, Rei Rasmussen, a student of Dr. Went, discovered surprisingly high emissions of isoprene from certain plants and spent the next decade convincing the scientific community that isoprene emissions were real. Rasmussen joined the faculty at Washington State University (WSU) where he developed the first regional estimates of isoprene and monoterpenes from North America (Rasmussen 1972). He collaborated with other WSU Professors (including Hal Westberg and Brian Lamb) and students (including Pat Zimmerman) who pioneered efforts to develop quantitative BVOC emission regional estimates in the 1970s (Zimmerman 1979). These collaborations led to a US biogenic emission model suitable for regional air pollution modeling developed by Lamb, Westberg and WSU PhD students Alex Guenther and David Gay (Lamb, Guenther, Gay and Westberg, 1987). In 1990, USEPA scientist Tom Pierce used this model as the basis for a FORTRAN code , called the Biogenic Emission Inventory System (BEIS), that could be used by EPA and local agencies for air quality management (Pierce and Waldruff 1991). Guenther joined Zimmerman at the National Center for Atmospheric Research (NCAR) and worked on improving the BVOC emission estimates including a global scale version for the Global Emissions Inventory Activity (GEIA) led by Tom Graedel of AT&T Bell Laboratories (Guenther et al. 1995). NCAR and EPA scientists, including Pierce and Chris Geron, collaborated on improving the BEIS model throughout the 1990s.
The original version of the MEGAN BVOC emission model was written in 2002 as an ACCESS Visual Basic code by Alex Guenther. The Visual Basic code was converted into a "stand-alone" FORTRAN code (MEGAN 2) by WSU PhD student Jack Chen. Guenther and colleagues continued to improve the MEGAN model and the updates were integrated into the "stand-alone" FORTRAN code by Tanarit Sakulyanontvittaya, a PhD student at the University of Colorado. This version of the code (MEGAN v2.04) was released publicly on October 29, 2007 along with the driving variables required to run the model. In 2012, Guenther and colleagues integrated new findings and improved parameters and driving variables into MEGAN version 2.10. MEGAN2.1 included a "stand-alone" FORTRAN code that was coded primarily by Xuemei Wang (then a Professor at Sun-Yat Sen University) and Tan Sakulyanontvittaya (then a scientist at ENVIRON). The code was also implemented into CESM/CLM by Collette Heald (MIT), WRF by Serena Chung (WSU), GEOS-Chem by Dylan Millet (U. Minnesota), SOSA by Michael Boy (U. Helsinki) and other chemstry and transport models (CTMs). Single-point versions of MEGANv2.1 (useful for comparing with flux tower data) were written in spreadsheet form in EXCEL Visual Basic by Guenther, in MATLAB by Thomas Karl (then a scientist at NCAR) and Python by Hui Wang (UCI PhD student).
Biogenic VOC emissions research and MEGAN development continues today with the BAI group at the University of California, Irvine and collaborators.