My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
WMOD00409
CWCB
>
Weather Modification
>
DayForward
>
WMOD00409
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
7/28/2009 2:38:32 PM
Creation date
4/16/2008 11:09:26 AM
Metadata
Fields
Template:
Weather Modification
Contract/Permit #
1-07-81-V0175
Title
State of Montana Activities in the High Plains Cooperative Program: 1981-1983
Date
6/30/1983
State
MT
Weather Modification - Doc Type
Report
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
174
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
Show annotations
View images
View plain text
<br />The objective analysis portion of SFCANL interpolates unevenly spaced data <br />points to a grid. This portion is incorporated in the subroutine HBINTS which <br />applies the Barnes (1964) techniques. This is basically an inverse <br />RZ-weighting scheme 1~hich allows multiple iterations. The degree of smoothing <br />for a particular ~avelength can be controlled by the parameter r, which defines <br />the 98% radius of influence, the number of passes, and grid spacing. The <br />maximum PROBE spacing was approximately 20 km, implying the shortest wavelength <br />(Nyquist) which can be defined in those areas is 40 km. Less than this must be <br />considered noise, and should be suppressed. Setting r = 30 km and using two <br />passes for this situation gives 63% response for a 40 km wavelength with <br />rapidly rising response for increasing wavelengths, and adequately suppresses <br />shorter lengths. <br /> <br />The analysis of wind, variables of state, and most quantities derived from <br />those is straightfongard. Those quantities requiring various derivatives need <br />some explanation. These are horizontal kinematic divergence, Qh'V, horizontal <br /> <br />moisture divergence, ;;Jq'vand the vertical component of relative vorticity, <br /> <br />k.QxV. Using the following notation for spatial indices, and grid <br /> <br />interval: <br /> <br />i = grid index for x = west-to-east, <br /> <br />j = grid index for y = south-to-north, and <br /> <br />(1) <br /> <br />'\?s= grid interval (length) I' <br /> <br />using the bar to indicate averaging over 5n minutes, gives centered-space <br /> <br />finite difference algorithm for the above derived quantities. <br /> <br />Vh. Y. (ui+1,j - uj,_l,j +vi,j+l -Vi,j_l)/2/!,s <br /> <br />(2) <br /> <br />~ ~ <br />Vh q' V :: <br /> <br />(qi+l ,u.+1 . - q. 1 .u. 1 . + q. v - q1. ,J._IVi,j_l)/2b.s <br />,J 1 ,J 1- ,J 1- ,J 1,j+l i ,j+l <br /> <br />(3) <br /> <br />~ ....\.... - - <br /> <br />k . VxV - (vi+1,j - V'i_l,j - Ui,j+l + Ui,j-l)/211s <br /> <br />(4) <br /> <br />Gradients across grid boundaries were approximated by using the outer two grid <br />points and dividing bY6s instead of 26s. Pressure tendency was simply the <br />difference between the time of interst and that 5n minutes prior. <br /> <br />29 <br />
The URL can be used to link to this page
Your browser does not support the video tag.