Terms of Reference

The role of the Committee on Mesoscale Processes is to provide a forum to promote the basic scientific understanding of mesoscale events and phenomena occurring in the earth’s atmosphere and oceans, and to promote their accurate representation in conceptual and numerical models. From a dynamical point of view, "mesoscale" refers to circulations that are sufficiently large to be hydrostatic, yet too small in scale to be quasigeostrophic. Thus, the study of the mesoscale spans the traditional separation between the synoptic and planetary scales and the microscale. Examples of the former include baroclinic instability, planetary waves, blocking, and the general circulation, whereas examples of the latter include convection, cloud dynamics and microphysics, and small-scale gravity waves. Phenomena and processes that may be characterized as mesoscale include fronts and frontogenesis, inertia–gravity waves, ageostrophic and hydrostatic flows that are thermally or mechanically forces, mesoscale waves and instabilities, cloud systems resulting from the growth and interaction of convective elements and thus organized on scales significantly larger than individual convective plumes, waves and turbulence acting to transfer energy between the synoptic- and microscales, and the atmosphere’s dynamical response to cloud microphysics, radiation, and other processes rooted at small scales.

It is the contention of the committee that significant opportunities remain for advancing the state of fundamental knowledge and understanding of the mesoscale. These opportunities are due in part to continued rapid development of observing and computing technologies suitable for mesoscale research, including the emergence of sophisticated national observing networks and high-resolution numerical models. It is considered axiomatic by the committee than an accurate physical description and theoretical understanding of mesoscale processes are both necessary conditions for the synthesis of a comprehensive view of atmospheric and oceanic dynamics. In turn, this comprehensive view is considered to be a requirement for improving weather forecasting, in general, and the forecasting of severe weather events, which are of a highly intermittent and localized nature, in particular.

On the basis of the foregoing considerations, the primary objectives of the committee are to

  1. maintain awareness of developments in mesoscale meteorology and oceanography, as well as progress is related disciplines of primary concern to other committees, such as the Committees on Atmospheric and Oceanic Waves and Stability, Boundary Layers and Turbulence, Cloud Physics, Measurements, Radar Meteorology, Severe Local Storms, Tropical Meteorology and Tropical Cyclones, and Weather Analysis and Forecasting;
  2. foster an active dialogue between those engaged in basic research in these fields and those who apply these sciences for the benefit of humankind;
  3. advise the Society of developments in mesoscale meteorology and oceanography as they pertain to the Society’s educational and information programs, as they may affect other committees of the Society, and as they may be applied by government and industry; and
  4. arrange scientific programs for AMS-sponsored conferences, symposia, workshops, and promote external educational programs to achieve the above goals.