A brief introduction to GOES Sounder products at CIMSS McIDAS (… in 25 slides or less ?) 1. File is: intro-GSndr-prods-CIMSS-incl-McI-20111004.ppt. [GSW] 2. Updated last slide (#24); rename: intro-GSndr-prods-CIMSS-incl-McI-20120104.ppt. [GSW]

Launch Schedule GOES “So Amer” GOES East (14) (15) GOES R series is a follow-on to the existing line of NOAA’s geostationary weather satellites. GOES I series [8-12]: Operational since 1994 GOES N series [13]: N launched May 24 2006, O planned launch late 2009, P planned launch 2010. Based on an availability analysis of the current GOES I and N-series, a GOES-R launch is required in the 2015 timeframe to maintain mission data continuity. Update 2011-02-14: GOES-0 – 14 launched 2009-06-27; GOES-P – 15 launched 2010-03-04.

Hourly GOES Sounder Footprints Pacific floater West CONUS East CONUS Atlantic floater hh:24 hh:01 hh:46 hh:20 GOES-West (-11) GOES-East (-13)

Rationale to approach the GOES Sounder (TPW 18>22 UT 10 Feb 2009) Start from good base [(sounder(s) operating nominally]. Follow the strengths [temporal monitoring; moisture]. Deal with the “weaknesses” [vertical resolution; clouds]. Build confidence [synergize with other (satellite) data]. Share your critiques [what is helpful / what is not].

All GOES Sounder Spectral Bands 18 UTC on 13 May 2009

Infrared electromagnetic spectrum of the atmosphere Spectral response functions for the 18 infrared GOES Sounder bands, separated into long, mid, and shortwave sections. Incoming solar radiation peaks in the visible, near 0.5 um (corresponding to a radiative temperature of 5780K for the Sun’s surface); outgoing terrestrial radiation peaks in the infrared, near 11 um (corresponding to an average earth radiative temperature of 255K). [ from Wein’s Law] Various gaseous constituents effect the amount of absorption at the different wavelengths.

All GOES Sounder Spectral Bands Hourly animation: 12UTC on 13 May 2009 – 12 UTC on 14 May 2009

The retrieval concept (in 25 words or less) Perturb the first guess profile (surface reports, GFS forecast, and SST), and thus, the resulting, calculated radiances (via RTE), until those calculated radiances match the observed radiances; when satisfied, that perturbed profile is the (final) retrieved profile. T P Of course, many other issues (instrument noise, transmittance function accuracy, number of vertical levels, surface emissivity calculations, …, and obscuring clouds) come into play with successfully solving the matrix inversion of the perturbation form of the radiative transfer equation, simultaneously for temperature and moisture.

GOES Sounder Retrieval System

Fundamental CIMSS research: striving to make quality real-time GOES Sounder radiance observations into practical useful information for weather forecasting Atmospheric continuity and evolution are clearly evident in multi-spectral animation. Where will clouds be? Comparison between observed imagery (bottom) and forecast imagery (top) builds confidence in how well the CRAS model is assimilating retrieved GOES Sounder cloud and moisture information. Where will forecast (GFS) moisture need to be modified, monitoring trends, to provide a better forecast for convection (as across Texas)? Differences between retrieved GOES Sounder TPW and the GFS forecast values are plotted over the GOES TPW Derived Product Imagery (DPI). [1800 UT 2 Apr 2004]

Temporal and spatial evolution of GOES Sounder LI DPI 10 Feb 2009 Sequence of GOES Sounder Derived Product Imagery (DPI) of Lifted Index (LI) stability, following clearing of frontal cloud cover, supports convective development across Oklahoma and Texas on 10 Feb 2009. Does the instability evolution provide any new, value-added information for a forecaster?

Small scale view of GOES Sounder SFOV LI DPI The SFOV resolution is evident (the nominal sub-satellite 10 km FOV being ~ 11-16 km over the Midwest). However, practical confidence remains stronger with the larger pattern and the temporal trend. {21 UT 13 Apr 2006 – 03 UT 14 Apr 2006}

Statistical assessment of SFOV retrieved TPW GOES-12 (wrt raobs) RMSE for Guess RMSE for Retrvls SFOV 3.68 3.43 3x3 FOV 3.02 2.84 5x5 FOV 3.45 3.03 GOES-11 (wrt raobs) 4.13 3.91 3.44 3.48 3.98 3.99 GOES-10 (wrt raobs) 2.69 2.38 2.44 3.35 2.64 W W W For a one year period (01 Sep 2005 – 31 Aug 2006), GOES Sounder retrieved Total Precipitable Water vapor (TPW) values (in mm), and their first guess (GFS) values, were compared with co-located (within 11 km) radiosonde observations. W T T WTW {Computations generously provided by J. P. Nelson (CIMSS) and A.S. Allegrino (OPDB).}

An Improved GOES Sounder Retrieval Algorithm 24 Apr 2007 An improved retrieval algorithm has been demonstrated in: Li, Z., J. Li, W. P. Menzel, T. J. Schmit, J. P Nelson III, J. Daniels, and S. A. Ackerman (2008), GOES Sounding improvement and applications to severe storm nowcasting, Geophys. Res. Lett., 35, L03806, doi10.1029/2007GL032797. Better stability evolution Improvements were made to the Ma et al. (1999)-based version of the GOES physical retrieval algorithm by employing: a regression-retrieved temperature and moisture first-guess (versus a forecast), a real covariance matrix for the first-guess (versus a correlation coefficient matrix), a new radiance bias adjustment scheme along with inverted cone filtering, and the “PFAAST” transmittance model (for calculated radiances).

An Improved GOES Sounder Retrieval Algorithm (1a) The old (Ma 1999) and new (Li 2008) versions of the GOES Sounder retrieval (vertical profile) algorithm are compared with total precipitable water (TPW) data from 12 UT on 06 May 2009 over the south central US. {http://cimss.ssec.wisc.edu/goes/realtime/scus/begin-scus.html} Profile comparisons (in skewT/logP diagrams) are shown in following slides for Slidell, LA and Corpus Christi, TX and support the noted improvement with the Li 2008 data in significantly reducing the extreme (erroneous) TPW values produced by the Ma 1999 version. The next question, then, is do the Li 2008 retrievals actually improve upon the first-guess? (Ma 1999) (Li 2008) Derived Product Imagery (DPI) of TPW with no clouds included.

An Improved GOES Sounder Retrieval Algorithm (1b) First-guess profiles Radiosonde profiles Ma(1999) retrieval profile Li(2008) retrieval profile Low level moistening = over rated TPW Minimal low level change = excellent (integrated) TPW

An Improved GOES Sounder Retrieval Algorithm (1c) First-guess profiles Radiosonde profiles Ma(1999) retrieval profile Li(2008) retrieval profile Extreme moistening = unrealistic TPW Note that Li(2008) version allows more (though still small) temperature changes from the first-guess; with Ma(1999), the temperature change seems non-existent. Modest compensation = slightly moist TPW

GOES-R Product List (Total: 68) Product Set Number: 1-4 1 Aerosol Detection (including Smoke & Dust) 3 Aerosol Particle Size 2 Volcanic Ash: Detection and Height 4 Aircraft Icing Threat 3 Cloud Imagery: Coastal 1 Cloud & Moisture Imagery (KPPs) 3 Cloud Layers / Heights & Thickness 3 Cloud Ice Water Path 3 Cloud Liquid Water 1 Cloud Optical Depth 1 Cloud Particle Size Distribution 1 Cloud Top Phase 1 Cloud Top Height 1 Cloud Top Pressure 1 Cloud Top Temperature 3 Cloud Type 3 Convective Initiation 4 Enhanced “V” / Overshooting Top Detection 2 Hurricane Intensity 3 Low Cloud & Fog 2 Lightning Detection 3 Turbulence 4 Visibility 1 Suspended Matter / Optical Depth 2 Geomagnetic Field 4 Probability of Rainfall 4 Rainfall Potential 2 Rainfall Rate / QPE 1 Legacy Vertical Moisture Profile 1 Legacy Vertical Temperature Profile 2 Derived Stability Indices (5) 1 Total Precipitable Water 3 Total Water Content 1 Clear Sky Masks 1 Radiances 3 Absorbed Shortwave Radiation: Surface 3 Downward Longwave Radiation: Surface 2 Downward Solar Insolation: Surface 2 Reflected Solar Insolation: TOA 3 Upward Longwave Radiation: Surface 3 Ozone Total 3 SO2 Detection 2 Derived Motion Winds 2 Fire / Hot Spot Characterization 4 Flood / Standing Water 2 Land Surface (Skin) Temperature 3 Upward Longwave Radiation: TOA 3 Surface Albedo 3 Surface Emissivity 4 Vegetation Index 4 Currents 4 Sea & Lake Ice: Age 4 Sea & Lake Ice: Concentration 4 Sea & Lake Ice: Extent 4 Sea & Lake Ice: Motion 4 Ice Cover / Landlocked: Hemispheric 2 Snow Cover 4 Snow Depth (Over Plains) 2 Sea Surface Temps 2 Energetic Heavy Ions 2 Mag Electrons & Protons: Low Energy 2 Mag Electrons & Protons:Med & High Energy 2 Solar & Galactic Protons 2 Solar Flux: EUV 2 Solar Flux: X-Ray 2 Solar Imagery: X-Ray 4 Vegetation Fraction: Green 4 Currents: Offshore F&PS v9b ABI – Advanced Baseline Imager Continuity of GOES Legacy Sounder Products from ABI SEISS – Space Env. In-Situ Suite EXIS – EUV and X-Ray Irradiance Sensors GLM – Geostationary Lightning Mapper Magnetometer SUVI – Solar extreme UltraViolet Imager

Information content of atmospheric vertical profiles Only a hyperspectral sounder (e.g. an IR interferometer, such as GIFS, AIRS, or IASI) appears sufficient to provide vertical resolutions comparable to those from in-situ radiosondes. Until a “Hyperspectral Environmental Sounder”-type instrument is restored, geostationary satellite sounding will remain limited.

TPW from different algorithm versions of GOES Sounder profile retrieval software Li et al (2008) version at CIMSS NWP (GFS) First-guess Li et al (2008) version at “R2O” Ma et al (1999) version at OPS 24 Sep 2011

Comparison of GOES Sounder TPW (and guess) versus GPS-Met TPW For week of 20 through 26 Sep 2011, note below how the Li-version of the GOES Sounder TPW generally improves upon both the bias and RMS (vs GPS), as compared to the Ma-version. Too wet The “old” Ma et al (1999) version Noisy 1. File name: GOES-TPW-v-vers-v-guess-v-GPS-20110920-26.ppt. [GSW] 2. Plots were redone, after the actual poster was printed for the Oct 2011 NWA annual meeting. By mid Oct 2011, K. Holub made corrections to the bias and rms routines for the ESRL GPS-v-GOES tool. [http://gpsmet.noaa.gov/ssec/] 3. This slide was actually re-made on 2012-01-04, while the (full) poster was re-made with correct rms plots on 2011-10-28. [http://cimss.ssec.wisc.edu/~garyw/nwa2011/Improve-GOES-Sndr-Algo-for-Ops-NWAmtg-BHM-20111021-gsw.ppt] Less wet The “new” Li et al (2008) version GPS (Global Positioning Satellite)-determined Total Precipitable Water (TPW), from across the US, provided by NOAA/OAR/ESRL (S. Gutman, D. Birkenheuer, K. Holub). Similar