Status of Atmospheric Status of Atmospheric Winds in Relation to Winds in Relation to Infrasound Infrasound Douglas P. Drob Douglas P. Drob Space Science Division Space Science Division Naval Research Laboratory Naval Research Laboratory Washington, DC 20375 Washington, DC 20375
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Drob Atmospheric Winds - University of California, San Diego · Global Forecast System (GFS) Nation’s Operational Workhorse (analysis and forecasts, 6 hours intervals, out to 16
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Status of Atmospheric Status of Atmospheric
Winds in Relation to Winds in Relation to
InfrasoundInfrasound
Douglas P. DrobDouglas P. DrobSpace Science DivisionSpace Science Division
Naval Research LaboratoryNaval Research LaboratoryWashington, DC 20375Washington, DC 20375
GOT WINDS?GOT WINDS?
Douglas P. DrobDouglas P. DrobSpace Science DivisionSpace Science Division
Naval Research LaboratoryNaval Research LaboratoryWashington, DC 20375Washington, DC 20375
G.O.T.S. WIND?G.O.T.S. WIND?
Douglas P. DrobDouglas P. DrobSpace Science DivisionSpace Science Division
Naval Research LaboratoryNaval Research LaboratoryWashington, DC 20375Washington, DC 20375
Global Forecast System (GFS)� Nation’s Operational Workhorse (analysis and forecasts, 6 hours intervals, out
to 16 days)
� This is the only global ‘numerical weather prediction’ model for which all output is free, over the internet (as a result of U.S. law), and as such is the basis for most web based forecast services, AccuWeather, The Weather Channel, the Weather Underground etc.
� Model Specifics
� Horizontal- spectral triangular 254 (T254); gaussian grid of 768X384, 0.5 x 0.5 degree latitude/longitude.
� Vertical 0 – 45 km (0.27 hPa), sigma coordinates, 64 layers with enhanced resolution at bottom and top
� Modern Era Retrospective-Analysis for Research and Applications (MERRA)
� Reprocessing of atmospheric observations from 1979 to present using the GEOS-5 Data Assimilation System; through 2007 to be completed by August, 2009.
� The focus of MERRA is the hydrological cycle.
� For data access - http://disc.sci.gsfc.nasa.gov/MDISC/
From http://gmao.gsfc.nasa.gov/pubs/docs/Rienecker372.pdf
From Steve Pawson (NASA GSFC) http://gmao.gsfc.nasa.gov/pubs/docs/Pawson375.pdf
From later in presentation (DPD)
GEOS-5 still
better than
climatology
below 65 km on
any given day!
(DPD)
HWM07 (+NRLMSIS-E)The recently upgraded Horizontal Wind Model (HWM07) provides a statistical
representation of the horizontal wind fields of the Earth’s atmosphere from the ground to the exosphere (0 to 500 km).
It is a empirical model (a compact Fortran-90 subroutine) that is function of geographic location, altitude, day of the year, solar local time, and geomagnetic activity.
The model includes representations of the zonal mean circulation, stationary planetary waves, migrating tides, and the seasonal modulation thereof; these are forced harmonic oscillation which to first order dominate the meteorology of the upper atmosphere.
There are 18,840 unknown model parameters that are estimated with a novel sequential estimation process from 60 × 106 available data points from 35 different satellite, rocket, and ground-based instruments spanning a period of over 50 years.
Drob, D. P., et al. (2008), An empirical model of the Earth’s horizontal wind fields: HWM07, J. Geophys. Res., 113, A12304, doi:10.1029/2008JA013668.
HWM07 Observational Database
Average WINDII zonal winds as function of height (black), and corresponding results from HWM93 (red) and HWM07 (blue). The results represent quiet-time (Kp< 3), December solstice (November-February) conditions in the indicated local time and latitude bins. The models were evaluated for the conditions of each observation, then binned and averaged in the same way as thedata. Error bars denote the estimated uncertainty of the mean.
Same as last figure, except for the meridional component.