1. University of Colorado and NCAR START08/Pre HIPPO Workshop
HIRDLS Observations of the Extra-Tropical UTLS and NRT Data During START08
John Gille
University of Colorado and NCAR
START08/Pre HIPPO Workshop
9 January 2008

2. High Resolution Dynamics Limb Sounder (HIRDLS) Experiment
A 21 channel infrared limb scanner, selected for its ability to:
• Sound the tropopause region,
• Get high vertical resolution
• Measure temperature, H2O,
O3, NO2, CH4, N2O, HNO3,
ClONO2, F11, F12, N2O5
• Cirrus, PSC’s and aerosol
heights, amounts
and characteristics
Upper limits for T and O3 nominal-
may be extended to ≥ 90 km in future
80km
0 km
60km
40km
20km O3
CH4
CFC11
Aerosol
HNO3
NO2
T/p
H2O
N2O
CFC12
ClONO2
N2O5
(Red- Presently available species)
Significant advances -
Optically thin channels to sound tropopause region
Capability for high vertical resolution (≤ 1 km)
Capability for high horizontal resolution (≤ 400 x 500 km)
Long life (> 5 years)

3. HIRDLS Averaging Kernels & Resolution 46°N, 15 Jan 2007
Detectors subtend about 1.2 km vertically at the limb, sampled every 200 m.
With low noise, permits high vertical resolution.
Data reported every 0.67 km, ~ 10% in pres.
START08, 1/9/08 3

4. Summary of HIRDLS T and O3 evaluations
ECMWF – HIRDLS, T, K
Comparison of HIRDLS temperatures with analyzed ECMWF temperatures interpolated to HIRDLS measurement locations. Mean and standard deviations of HIRDLS minus ECMWF temperature differences over full latitude range of HIRDLS measurements. From Gille et al., 2008.
Ozone difference between HIRDLS and ozonesondes (20+ sondes using 0.5% KI cathode solution) from the summer 2006 WAVES Campaign, sited in Beltsville, MD, 39N, 77W. Ozone differences are shown in terms of mixing ratio From Nardi et al., 2008.

5. High Vertical Resolution Ozone Measurements in the E. Pacific
(Hilo)

6. HIRDLS Temperature, Ozone and Nitric
Acid along Orbital Track in E. Pacific
Note double
tropopause
Solid white lines-scaled Ertel PV.
Dashed lines
indicate
u in m/s

7. Comparison Between HIRDLS and NCEP GFS Static Stability
From Laura Pan

8. HIRDLS Along-track Ozone Cross- Section And GFS Static Stability
GFS d/dz
From Laura Pan

9. HIRDLS T & O3 Cross-sections in the E. Pacific UT/LS
Jan
Along-track temperature and ozone fields for late January, 2006, showing evolution of transports between low latitude UT and mid-latitude LS
Days from the top:
January 20, 21, 23, 25, 26.

10. GEOS-5 Cross-sections of Temperature Potential Vorticity, and Ozone

11. Laminar Structure in UT/LS 1 April 2006

12. HIRDLS SCAN TRACKS FOR 1 DAY OVER U.S.
Red- Ascending Orbit
~ 3 PM local time
Blue- Descending Orbit
~ Midnight local time

13. HIRDLS Near-Real Time Data for START08
In early stages of development
Technical Problems- timely acquisition of
- S/C attitude and ephemeris data
- Forecast GMAO data for LOS gradient calculations
- HIRDLS L0 data
Solutions exist- need to be implemented & tested
Should be possible to automate, process orbit within a few hours of observations
Midnight-over Boulder, & West Coast, available following morning
Daytime passes - Possible coincidences with HIAPER flights

14. Conclusions- 1
HIRDLS 1 km vertical x 1° latitude resolution allows detection of thin layers in the UT/LS
x/z = 102 ~ N/f gives dynamically consistent observations
 Shows double tropopause
Poleward motion of UT tropical air (low ozone and HNO3),
Equatorward motion of mid-latitude LS air (high ozone and HNO3)
Layers are consistent with contours of GEOS5 scaled Ertel PV
Locations of thin layer structures in the UT/LS can be found from column ozone maps of OMI and GEOS5, as well as GEOS5 and GFS temperature and PV maps

15. Conclusions -2
GEOS5 PV & T analyses capture thin layer structures, while O3 analysis does not.
These layers almost certainly result in mixing, although more extensive study needed
Many questions remain. HIRDLS data will help to explore O3 and tracer transport/mixing in the UTLS region.
HIRDLS NRT data should aid in START08 flight planning.
HIRDLS data should provide important support to achieving START08 objectives.

17. Correspondence between GEOS-5 PV & Ozone Maps and Cross-Sections