Surface Ocean - Lower Atmosphere Study (SOLAS) Project Integration

Ammonia (NH3)

The air-sea exchange of ammonia is important as acid-base reactions in the atmosphere efficiently form fine mode aerosol ammonium sulphate by gas to particle conversion (Raes et al., 2000). It has also been argued that ammonia allows more rapid formation of new aerosol particles (Yu, 2003), which have a relatively high light scattering coefficient and are also efficient cloud condensation nuclei.

Due to the intensification of agricultural practice, the dominant global source of atmospheric NH3 is terrestrial and this has significant impacts on the present air-sea flux. In contrast, measurements in the remote marine environment have proven difficult due to the low concentrations in both atmosphere and ocean. Despite this, there are indications that the flux may sometimes be from the ocean to the atmosphere (Jickells et al., 2003).

No global data set currently exists of ocean/atmosphere NH3 concentrations.

  1. Jickells, T.D. et al. (2003) Isotopic evidence for a marine ammonia source. GRL 30: art. no.-1374.
  2. Raes F. et al. (2000) Formation and cycling of aerosols in the global troposphere. Atm Env 34: 4215-4240.
  3. Yu, F. Q. (2003) Nucleation rate of particles in the lower atmosphere: Estimated time needed to reach pseudo-steady state and sensitivity to H2SO4 gas concentration. GRL 30: art. no.-1526.

Implementation Group 1 also examines these other short-lived components:

Dimethyl Sulphide | Organohalogens | Alkyl nitrates | Isoprene | Methanol | Aerosol and rain