hydrometeor loading

Hydrometeor loading is the induced drag effects on the atmosphere from a falling hydrometeor. When falling at terminal velocity, the value of this drag is equal to gr_h, where g is the acceleration due to gravity and r_h is the mixing ratio of the hydrometeors. Hydrometeor loading has a net-negative effect on the atmospheric buoyancy equations.{{cite book|last=Markowski|first=Paul|title=Mesoscale Meteorology in Midlatitudes|year=2010|publisher=John Wiley & Sons, Ltd.|location=West Sussex, UK|isbn=978-0-470-74213-6|pages=20|author2=Yvette Richardson}} As the hydrometeor falls toward the surface, the surrounding air provides resistance against the acceleration due to gravity, and the air in the vicinity of the hydrometeor becomes denser.{{cite arXiv |last=Asnani |first=G.C. |author2=M. K. Rama Varma Raja |title=A New Hypothesis for Layers of High Reflectivity Seen in MST Radar Observations |eprint=physics/0003028v1 |date=March 2000 }} The increased weight of the atmosphere can support a present downdraft or even cause a downdraft to occur.{{cite web|last=Geerts|first=B|title=Microbursts|url=http://www-das.uwyo.edu/~geerts/cwx/notes/chap08/microburst.html|website=Learning about weather and climate: some short articles|accessdate=16 October 2011 |author2=E. Linacre |author3=L. Oolman}} Hydrometeor loading can also lead to increased high pressure inside of a mesohigh in a thunderstorm.{{cite journal|last=Sanders|first=Frederick|author2=Kerry A. Emanuel|title=The Momentum Budget and Temporal Evolution of a Mesoscale Convective System|journal=Journal of the Atmospheric Sciences|date=February 1977|volume=34|issue=2|pages=322–330|doi=10.1175/1520-0469(1977)034<0322:TMBATE>2.0.CO;2|bibcode = 1977JAtS...34..322S |doi-access=free}}