What (if any) effect does wind speed have upon observed precipitation?

Main topic: Science

Other topics: Physics

Short answer: Increased evaporation is caused by higher wind speeds, which in turn destabilise the boundary layer, which in eventually stimulate deep convection and ultimately results in greater precipitation.

Overview

When wind speeds are higher, there is a greater transfer of latent heat from the ocean to the air via the process of evaporation. There is a statistical connections between "forkings" such as the evaporative moistening of the planetary boundary layer and precipitation in locations that experience persistent convection. These correlations may be expected to exist. When compared to the daily precipitation quantities that are commonly seen in mesoscale convective complexes, the quantity of water that is introduced through evaporation alone is rather low. Instead, moisture convergence is the primary immediate source of moisture for the precipitation that is occurring. This points to the presence of a phenomenon known as "convergence feedback," in which very modest increases in evaporation are responsible for much bigger rises in moisture convergence and precipitation.

The interpretation of the link between wind speed and precipitation

Even though moisture convergence is the primary source of moisture for precipitation, this does not mean that it should consider it to be a conceptually distinct external forcing that "causes" precipitation. Instead, it should consider moisture convergence to be a source of moisture in its own right. It is possible to interpret the convergence of moisture as a reaction to the latent heating caused by deep convection. This line of reasoning is flawed due to the fact that latent heating happens as a consequence of moisture convergence and condensation. To explain when and where convection occurs inside large-scale zones of mean convergence like the ITCZ, a distinct conceptual framework is necessary.

Increased evaporation is caused by greater wind speeds, which destabilises the boundary layer and may result in the initiation of deep convection. The quantification of this thesis, on the other hand, reveals a surprisingly nuanced nature. It is necessary to draw the conclusion that a convergence feedback is taking place since the observed elevations in precipitation are much bigger than the changes in evaporation that are related with the increased wind speed.

Different wind speeds

The same sort of pattern or storm may take many various forms depending on the speed of the wind, how high it is in the atmosphere, and whether it is blowing over land or ocean.

Conclusions

There is a considerable association between wind speed and precipitation under situations when there is a high column relative humidity, which are conditions under which it is probable that deep convection will develop. The angle of the slope of the link between wind speed and precipitation varies among geographies and climbs steeply as circumstances become more humid. Surface wind speed only explains a tiny portion of the daily rainfall variability, but it does provide some helpful insight into how surface forcing modifies tropical convection. Additionally, it offers an intriguing test for large-scale prediction models in the Tropics. The data obtained from QuikSCAT indicate that the correlation is not connected to the mesoscale gustiness that is caused by convective systems. As a result, the increased surface fluxes are probably what's behind the rise in the occurrence of deep convection.

Higher wind speeds, from a purely physical standpoint, lead to an increase in evaporation, which in turn destabilises the boundary layer and has the potential to cause deep convection. The quantification of this argument, on the other hand, reveals a surprisingly nuanced nature. We are able to draw the conclusion that a convergence feedback is taking place since the observed changes in precipitation are much bigger than the changes in evaporation that are linked with the increased wind speed.

Assessing column moist static energy budgets have led to a further interest in exploring the degree to which existing ideas concerning column moist static energy budgets and gross moist stability are supported by reanalyses and CRM simulations.