These are ASCII Text output of the Atmospheric Motion Vectors (AMVs, also known as ‘cloud drift winds’) from North Pole region and South Pole region. These are derived from specialize satellite composite imagery using both low Earth orbiting (LEO) and geostationary (GEO) satellites, since the product is known as LEOGEO AMVs. Files are labeled as: WIND.xx.Dyyddd.Thhmm00.txt where xx is the polar region, SP for South Pole region and NP for North Pole region, yy is the last two digits of the year, ddd is the day of the year, hh is the hour, and mm is the minutes. The columns of data inside the files have:

type = IR is the infrared satellite composite used to make the AMVs

sat = LG is for LEOGEO type of wind

day = Day, in yyymmdd format, with yyyy the year, mm the month, and dd the day

hms = Time in Hours, Minutes and Seconds, UTC

lat = Latitude (positive North)

lon = Longitude (positive West – not East longitudes are negative)

pre = Pressure level of the wind in millibars

spd = Wind Speed in meters per second

dir = Wind direction

rff =Recurve filter Flag (see Hayden and Purser 1995, Velden et al. 1997)

qi = Quality Indicator (see Holmlund, 1998 and Holmlund et al., 2001)

Hayden, C. and R.J. Pursor, 1995. Recursive filter objective analysis of meteorological fields: Applications to NESDIS operational processing. J. Appl. Meteor., 34, 3−15.

Holmlund, K., 1998. The utilization of statistical properties of satellite−derived atmospheric motion vectors to derive quality indicators. Weather and Forecasting, 12, 1093−1103.

Holmlund, K., Velden, C. and Röhn., M. 2001. Enhanced automatic quality control applied to high-density satellite derived winds. Mon. Wea. Rev. 129, 517 – 529.

Velden, C., C. M. Hayden, M. S. J. Nieman, W. P. Menzel, S. Wanzong, and J. S. Goers, 1997. Upper-Tropospheric winds derived from geostationary satellite water vapor observations. Bull. Amer. Meteor. Soc., 78, 173–195.