Modeling

GECKO-A

Lizard by genma Created2016-03-14 Description: lagartixa verde - green gecko. https://openclipart.org/detail/243979/lizardThe Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) is a hyper-explicit mechanism for the atmospheric oxidation of organic compounds. GECKO-A uses mechanistic and kinetic data from laboratory measurements where available, and applies various Structure-Activity Relations (SARs) when laboratory data are not available, to estimate rate coefficients and their temperature & pressure dependencies, possible multiple reaction pathways and products, and other molecular properties such as saturation vapor pressure, solubility (Henry’s Law coefficients), and UV-visible chromophores that lead to absorption and photolysis. Typical mechanisms generated by GECKO-A have ~105 distinct explicit molecules partaking in ~10 6 thermal and photolytic reactions.

The generated mechanism is typically used inside a 0D box model, and has been applied to study chemistry in urban and rural plumes, or simulate chamber experiments. The GECKO-A box model comes with a solver capable of handling the large number of species and reactions.

The development of GECKO-A is a collaborative effort between scientists at NCAR/ACOM and LISA/CNRS France. The GECKO-A generator is still a research code and can only be obtained for collaborative projects. However, a number of pre-generated mechanisms (see list below) can be made available for use with the box model.

GECKO-A Library for Selected Hydrocarbon Precursors

The GECKO-A Output Library provides the main gas and particle phase products from individual precursor hydrocarbons, under different conditions ranging from pristine remote to polluted urban. Results include distributions of functional groups, vapor pressures, solubility coefficients, yields of secondary organic aerosols (SOA) and van Krevelen diagrams of the oxidation pathways.

U.S. Funding:

National Center for Atmospheric Research (NCAR) https://ncar.ucar.edu/
U.S. National Science Foundation https://www.nsf.gov/
U.S. Department of Energy, Atmospheric System Research program https://asr.science.energy.gov/

National Center for Atmospheric ResearchNational Science FoundationU.S. Department of Energy

 

GECKO-A at LISA

Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA)
Led by Prof. Bernard Aumont http://geckoa.lisa.u-pec.fr/

Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA)

The chemical gecko, by Camille Mouchel-Vallon (ACOM / NCAR / UCAR).

UCAR/NCAR Share

                  

                  

ACOM | Atmospheric Chemistry Observations & Modeling