<html><head></head><body><div style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div><b>Hello,</b></div><div><br></div><div><b>I want to filter Rossby waves from zonal ocean velocities. can I use the function "kf_filter" and can I use zonal velocities to filter Rossby waves in ocean? I have tried to do and the script is below;</b></div><div><br></div><div><div><br></div><div>fi=addfile("/mnt/e/data/HYCOM/u/2004_june.nc","r")</div><div>vname=getfilevarnames(fi)</div><div>print(vname)</div><div><br></div><div>oc=fi->WATER_U(:,{0:200},{5.5},{76:86})</div><div>printVarSummary(oc)</div><div><br></div><div>t=fi->TIME</div><div>printMinMax(t, False)</div><div><br></div><div>obsPerDay=8</div><div>tMin=731734</div><div>tMax=731763.875</div><div>kMin = 1</div><div>kMax = 14</div><div>hMin=5</div><div>hMax=60</div><div>waveName="Kelvin"</div><div><br></div><div>x=oc(:,{40},:)</div><div>x!0="time"</div><div>x!1="lon"</div><div><br></div><div>kf=kf_filter(x(:,:), obsPerDay, tMin, tMax, kMin, kMax, hMin, hMax, waveName)</div><div><br></div><div>printMinMax(kf, False)</div><br></div><div><b>and the output information is below;</b></div><div><div><br></div><div>Variable: vname</div><div>Type: string</div><div>Total Size: 64 bytes</div><div> 8 values</div><div>Number of Dimensions: 1</div><div>Dimensions and sizes: [8]</div><div>Coordinates:</div><div>(0) LON2876_3501</div><div>(1) LON2876_3501_bnds</div><div>(2) LAT876_1251</div><div>(3) LAT876_1251_bnds</div><div>(4) LEV1_28</div><div>(5) LEV1_28_bnds</div><div>(6) TIME</div><div>(7) WATER_U</div><div><br></div><div>Variable: oc</div><div>Type: float</div><div>Total Size: 2782080 bytes</div><div> 695520 values</div><div>Number of Dimensions: 3</div><div>Dimensions and sizes: [TIME | 240] x [LEV1_28 | 23] x [LON2876_3501 | 126]</div><div>Coordinates:</div><div> TIME: [731734..731763.875]</div><div> LEV1_28: [ 0.. 200]</div><div> LON2876_3501: [ 76.. 86]</div><div>Number Of Attributes: 5</div><div> LAT876_1251 : 5.51999998093</div><div> missing_value : -30000</div><div> _FillValue : -30000</div><div> long_name : eastward water velocity [m/s]</div><div> history : From 3hourly</div><div>(0) time (days since 0001-01-01 00:00:00) : min=731734 max=731763.875</div><div>(0) eastward water velocity [m/s] : min=-0.00192383 max=0.00160925</div><div><br></div><div><span style="color: rgb(51, 51, 51); font-family: verdana, sans-serif; font-size: 13.3333px;">P.S; When I try to filter "Mixed Rossby-Gravity" waves, all output results were "zero". In above script, I have filtered "Kelvin" waves. I really appreciate if anyone could help me to figure out this and any suggestion about how to filter "Rossby waves" is appreciated in advance.</span><br></div><div><span style="color: rgb(51, 51, 51); font-family: verdana, sans-serif; font-size: 13.3333px;"><br></span></div><div><span style="color: rgb(51, 51, 51); font-family: verdana, sans-serif; font-size: 13.3333px;">Kind Regard;</span></div><div><span style="color: rgb(51, 51, 51); font-family: verdana, sans-serif; font-size: 13.3333px;">Chathu</span></div><br></div><div><br></div></div></body></html>