GPS Observations for Atmospheric Science Ground-based and Radio Occultation Observations for Weather, Climate and Ionosphere C. Rocken, S. Sokolovskiy, D. Hunt, B. Schreiner, B. Kuo, M.Sleziak, J. Braun UCAR / COSMIC Program - Boulder CO

Overview Ground based observations –Data availability Radio Occultation (RO) introduction Scientific and societal impact of RO –Weather –Climate –Ionosphere How to get RO data

Real-Time Network

Global Sites

GPS and MWR Comparisons Arctic rms = 0.73mm Mid-Latitude rms = 0.93 mm Tropics rms = 1.65 mm

BMB+PW GFS Six-Hour Forecast Using GPS PW

Data Access and Availability COSMIC processes stations in North America in hourly batches (and daily), using a 30 minute piecewise linear estimation strategy. Global stations are processed in daily batches. All data processed by the COSMIC program are available via the following methods –LDM distribution (see ) –Web distribution – Including NetCDF, ASCII download by network, and ASCII download by individual station. There is also a database interface that allows time series plotting and download queries –

Radio Occultation

Temperature [C] at 100 mb (16km) Evolving COSMIC Constellation

Comparison of collocated Profiles

Statistical comparison of FM3-FM4 Soundings separation < 10 km Schreiner et al % precision between km

Over 2.7 Million Profiles 4/21/06- 8/10/08 Neutral Atmosphere Ionosphere

Detection Of Boundary Layer With RO

ABL Height Observations During COSMIC Year 1 (bending angle gradient > 1e-2 rad/dH, height < 3 km)

Leading Weather Center Newsletters

Sean Healy, ECMWF ECMWF SH T Forecast Improvements from COSMIC Assimilation of bending angles above 4 km

Impact of COSMIC on Hurricane Ernesto (2006) Forecast Without COSMIC With COSMIC Results from Hui Liu, NCAR

Impact of COSMIC on Hurricane Ernesto (2006) Forecast GOES Image With COSMIC GOES Image from Tim Schmitt, SSEC

3-D structure of the feature during daytime ( constant LT) Weaker EIAStronger EIAWeaker EIA Stronger EIA 12:00 LT ↑ Tiger Liu, NCU

InputDataInputData CDAAC CDAAC NESDISNESDIS GTS NCEP ECMWF CWB UKMO Canada Met. JMA BUFR Files WMO standard 1 file / sounding Getting COSMIC Results to Weather Centers Data available to weather centers within < 180 minutes of on-orbit collection JCSDA NRL Operational Processing Science & Archive TACC

InputDataInputData CDAAC CDAAC LDM BUFR + wetPrf Files Getting COSMIC Results to Weather Centers Data available to any registered user with LDM access within < 180 minutes of on-orbit collection Real-Time Access for Science Users Science & Archive TACC Universities Companies Private users etc.

COSMIC Result Latency 20-Jul - 16-Aug 2008

* Select the 'Sign Up ' link under COSMIC Accept data use agreement * Enter information: Name, Address, , user_id, Password, planned use of data An will be sent within 2-3 business days to indicate access has been granted. If interested in real-time profiles indicate that LDM acess is requested COSMIC Data Access 825 data users from 46 countries are registered

Global FORMOSAT-3 / COSMIC Data Users ~825 users 46 Countries