lecture 6

IR High Spectral Resolution: 

IR High Spectral Resolution The Bologna Lectures Paul Menzel NOAA/NESDIS/ORA

CrIS Spectral Coverage: 

CrIS Spectral Coverage B

Interferometer measurements compared with physics calculations  : 

Interferometer measurements compared with physics calculations CO2 Lines

Slide4: 

Moisture Weighting Functions Pressure (hPa) Pressure (hPa) Advanced Sounder (3074) GOES (18) 1000 1000 100 100 UW/CIMSS High spectral resolution advanced sounder will have more and sharper weighting functions compared to current GOES sounder. Retrievals will have better vertical resolution.

Slide5: 

The advanced sounder has more and sharper weighting functions UW/CIMSS These water vapor weighting functions reflect the radiance sensitivity of the specific channels to a water vapor % change at a specific level (equivalent to dR/dlnq scaled by dlnp). Moisture Weighting Functions Pressure Weighting Function Amplitude Wavenumber (cm-1)

Slide6: 

Inverted TBB Atm Sfc Temp (K) Sfc Moisture (gm/Kg) Cold: 276 4 Warm/moist: 303 23 Hot/dry: 308 8 window UW-Madison/CIMSS

Slide7: 

IMG demonstrates interferometer capability to detect low level inversions: example over Ontario with inversion (absorption line BTs warmer) and Texas without (abs line BTs colder) Spikes down - Cooling with height Spikes up - Heating with height

Slide8: 

Cloud particle size is revealed in high resolution infrared spectra

Slide9: 

WV vertical structure revealed with Geo-Interferometer Altitude, km Two flight tracks from NAST-I during CAMEX-3 September 14, 1998 --------------------------125 km------------------------- RH %

Slide10: 

Analysis of NOAA global raob data (tropics and mid-lat summer) VAS - past GOES - current G18 - 18 1/2cm-1 chs G50 - 50 1/2cm-1 chs GAS - ABS 2000+ 1/2cm-1 chs RAOB - T to 150mb (Q to 300mb) Geo-Interferometer nears Raob-like depiction of atmosphere

GIFTS Simulation of Hurricane Bonnie: Winds from Water Vapor Retrieval Tracking: 

GIFTS Simulation of Hurricane Bonnie: Winds from Water Vapor Retrieval Tracking

Slide16: 

ABS TRD noise (upper) and CrIS brightness temperature spectra (lower) calculated for low level temperature inversion

Slide17: 

ABS/CrIS vs GOES retrieval for low level temperature inversion

Slide18: 

Current retrieval strategy: - use all channels in a regression for first guess - then use a sub-set of channels for physical retrieval

Slide19: 

1-km temperature rms and 2 km water vapor mixing ratio % rms from CrIS and GOES retrievals simulated from 590 global raobs Geo-I gets 1 K for 1 km T(p) and 15% for 2 km Q(p)

Slide20: 

Simulated CrIS and GOES CTP rms for very high (about 200 hPa), high (about 300 hPa), medium (about 500 hPa), and low (about 850 hPa) clouds with ECA from 0.1 to 1.0 using 75 CONUS raobs.

Slide21: 

Simulated Comparison of Current Sounder and ABS Significant improvements in surface and total column parameters are made with interferometers

Slide22: 

Time series of low-level vertical temperature structure during 9 hours prior to Oklahoma/Kansas tornadoes on 3 May 1999 Truth> Geo-I> Note Geo-I improves depiction of boundary layer heating and surface inversion Current GOES> Geo-I traces evolution of 800 hPa inversion with 60-80% error reduction

Slide23: 

3 May 1999 – Oklahoma/Kansas tornado outbreak Geo-I correctly captures the important vertical temperature variations GIFTS/GOES Retrieved-Temperature Errors Truth> Geo-I Errors> Standard Deviation = 0. 6o Note Geo-I reduces errors by 80% and captures 800mb inversion GOES Errors> Standard Deviation = 3. 5o

Slide24: 

Time series of low-level vertical moisture structure during 9 hours prior to Oklahoma/Kansas tornadoes on 3 May 1999 Truth> Geo-I> Note Geo-I retains strong vertical gradients for monitoring convective instability Current GOES> Geo-I traces moisture peaks and gradients with greatly reduced errors

Slide25: 

3 May 1999 – Oklahoma/Kansas tornado outbreak Geo-I correctly captures important vertical moisture variations GIFTS/GOES Retrieved-Moisture (g/kg) Errors Truth> Geo-I Errors> Standard Dev. = 0.9 g/kg Note Geo-I reduces errors and captures low-level moisture peaks and vertical gradients GOES Errors> Standard Dev. = 2.4 g/kg

Slide26: 

Expectations from the Geo-Interferometer * depicts water vapor as never before by identifying small scale features of moisture vertically and horizontally in the atmosphere * tracks atmospheric motions much better by discriminating more levels of motion and assigning heights more accurately * characterizes life cycle of clouds (cradle to grave) and distinguish between ice and water cloud ( which is very useful for aircraft routing) and identify cloud particle sizes (useful for radiative effects of clouds) * measures surface temperatures (land and sea) by accounting for emissivity effects (the improved SSTs would be useful for sea level altimetry applications) * distinguishes atmospheric constituents with improved certainty; these include volcanic ash (useful for aircraft routing), ozone, and possibly methane plus others trace gases.