Decreasing resolution of NetCDF data with GDAL

I have wind speed data which is in NetCDF format and lat=4320 lon=8640 and I want to convert it to a NetCDF file with lat=360 and lon=720. In other words, I want to change the resolution of my data whose resolution is 0.0416 degrees (1/24th), and convert it to 0.5 degrees. (By lon and lat, I mean longitude and latitude.) I have already used this code but I have some errors. Could you please help me?

gdal_translate -of netCDF -tr 0.5 0.5 WS.nc WS_1.nc   

Warning 1: No UNIDATA NC_GLOBAL:Conventions attribute

Input file size is 8640, 4320

0Warning 1: Recode from UTF-8 to CP_ACP failed with the error: "Invalid 
argument".

...10...20...30...40...50...60...70...80...90..Warning 1: Recode from UTF-8 to CP_ACP failed with the error: "Invalid argument".

.100 - done.