Published online by Cambridge University Press: 07 May 2010
ABSTRACT Some scaling properties of the distribution of rain rate in space are investigated. The scales of concern range from the radar coverage range (of the order of 400 km) down to individual raindrops. Preliminary results show that over this wide range of scales rain fields exhibit: preferential scales in the range of a few tens of kilometers; behaviour compatible with multifractal structure between scales of 0.5 to 12 km and some clustering properties of the distribution of the small raindrops in space probably related to raindrop collisions and breakup.
INTRODUCTION
Rain rate fields exhibit variability at all scales down to individual raindrops. In this sense the answer to the title question is positive. However, our interest focuses more on restrictive properties, such as scale invariance, that could serve in modelling the process. One should not expect the restrictive properties (if they exist) to extend uniformly over all scales of the rainfall fields. On scales smaller then the size of individual cumulus turbulence probably prevails in determining the distribution of water substance. On larger scales other phenomena will affect markedly the distribution of precipitation in space. For example, orography (including the distribution of humidity sources) plays undoubtedly a role in organizing convective elements.
The ability to study rain at all scales is limited. A single radar does not cover a typical precipitation system. Quantitative data from networks of radars covering extended areas are now only becoming operational.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.