# Presentation: 482081

## EOS-MLS and NDACC lidar temperature comparisons over the period September 2004 – July 2006

**  **

**Tao Li****1****, **_**Thierry Leblanc**__**1**_**, I. Stuart McDermid****1****,**
**Michael Schwartz and the MLS team****2**** **
*1**Jet Propulsion Laboratory**California Institute of Technology** Table Mountain Facility **Wrightwood, CA 92397*
*2** Jet Propulsion Laboratory**California Institute of Technology** Pasadena, CA 91109** *

**Lidar dataset**
- NDACC: Network for the Detection of Atmospheric Composition Change, 10 temperature lidars in network, 5 presented here.
- Rayleigh and N2 vibrational Raman backscattering by atmosphere
- Temperature retrieved from density using 1-point tie-on at top of profile and downward integration of hydrostatic balance
- Each profile retrieved for 2- to 6-hour integrated measurements, and 75- to 300-m vertical resolution, depending on NDACC station

**MLS dataset**
- Version 1.5 !
- Each profile retrieved every 15 s, with horizontal resolution of 165 km and vertical resolution of 3 km or more

**Other datasets**
- NCEP operational analysis interpolated at JPL lidar location, and time of lidar measurement
- NCEP-NCAR Re-Analsysis interpolated at JPL lidar location, and time of lidar measurement
- Hilo Radiosonde profiles within 6 hours of JPL-MLO lidar measurement

## The NDACC temperature Lidar stations

**  ****JPL TMF lidar station:**
-  - Table Mountain, California
- - Latitude: 34.4oN
- - Longitude: 117.7oW
-  Elevation: 2285 m
**JPL MLO Lidar station:**
- - Mauna Loa, Hawaii
- - Latitude: 19.5oN
- - Longitude: 204.4oW
-  Elevation: 3400 m
**CNRS OHP lidar station:**
-  Haute-Provence, France
- - Latitude: 44oN
- - Longitude: 6oW
-  Elevation: 679 m
-  PI (T): Alain Hauchecorne

** ****Ny-Alesund lidar station (AWI):**
-  -Spitzbergen, Norway
- - Latitude: 78.9oN
- - Longitude: 11.9oE
-  Elevation: 11 m
-  PI: Peter Van der Gathen
**DWD HOH lidar station**
-  Hohenpeissenberg, Germany
-  Latitude: 47.8oN
-  Longitude: 11oE
-  Elevation: 1000 m
-  PIs: Hans Claude/Wolfgang Steinbrecht

## MLS smoothes out mesospheric temp. inversion layers

**Black: lidar profiles  Horizontal bars = unsmoothed +/- tot. error**
**                                   ****Solid curves = smoothed using MLS kernels **

**MLS smoothes out mesospheric temp. inversion layers**
**MLS systematically warmer than lidar in the stratopshere**
**Time coincidences with MLO not optimized**

**Color: MLS profiles**
**           ****within +/- 6 hours and 500 km**

**MLS: Individual comparisons with TMF and MLO lidars**

## MLS - TMF lidar    (within +/- 6 hours and 400 km) 

**TMF lidar systematically 2 K colder than MLS in the stratosphere**
**Excellent agreement between 2 hPa and 0.07 hPa**
**Large Warm lidar bias in upper mesosphere**

**MLS - TMF lidar    ****(within +/- 6 hours and 400 km) **

## Comparisons MLS - TMF lidar (temperature)

## MLS – NCEP operational analysis at TMF

**MLS systematically warmer than NCEP in the stratosphere**
**Systematic bias decrease if MLS profile shifted up (2-3% pressure)**

**MLS – NCEP operational analysis at TMF**

## MLS – NCEP/NCAR Re-Analysis at TMF

**MLS – NCEP/NCAR Re-Analysis at TMF**

**MLS 1-2 K warmer than NCEP/NCAR re-analysis in the stratosphere**
**MLS colder than NCEP/NCAR re-analysis in the upper troposphere**
**Systematic bias is reduced if MLS shifted up (2-3% pressure)**

## MLS – Mauna Loa lidar    (within +/- 6 hours and 400 km) 

**MLO lidar systematically 1-2 K colder than MLS in the stratosphere**
**MLO lidar systematically 1-4 K warmer than MLS in the mesosphere**
**Large warm lidar bias in upper mesosphere**

**MLS – Mauna Loa lidar    ****(within +/- 6 hours and 400 km) **

## Comparisons MLS - MLO lidar (temperature)

## MLS – NCEP operational analysis at MLO

**MLS systematically warmer than NCEP in the stratosphere**
**Systematic bias decrease if MLS profile shifted up (2-3% pressure)**

**MLS – NCEP operational analysis at MLO**

## MLS – NCEP/NCAR Re-Analysis at MLO

**MLS 1-2 K warmer than NCEP/NCAR re-analysis in the stratosphere**
**MLS colder than NCEP/NCAR re-analysis in the upper troposphere**
**Systematic bias is reduced if MLS shifted up (2-3% pressure)**

**MLS – NCEP/NCAR Re-Analysis at MLO**

## MLS – Hilo Radiosondes (60 km east of Mauna Loa)

**MLS – Hilo Radiosondes (60 km east of Mauna Loa)**

**MLS 1-2 K warmer than radiosondes in the lower stratosphere**
**MLS colder than radiosondes in the upper troposphere**
**Systematic bias is reduced if MLS shifted up (2-3% pressure)**

## MLS – Haute-Provence (France) lidar    (within +/- 6 hours and 400 km) 

**OHP lidar systematically 1-2 K colder than MLS in the stratosphere**
**OHP lidar 2-4 K warmer than MLS in the mesosphere**
**Bias reduced if MLS profiles shifted up (2-3% pressure)**

**MLS – Haute-Provence (France) lidar    ****(within +/- 6 hours and 400 km) **

## MLS – Hohenpeissenberg (Germany) lidar    (within +/- 6 hours and 400 km) 

**HOH lidar systematically 1-2 K colder than MLS in the stratosphere**
**OHP lidar 3 K warmer than MLS in lower mesosphere**
**Bias reduced if MLS profiles shifted up (2-3% pressure)**

**MLS – Hohenpeissenberg (Germany) lidar    ****(within +/- 6 hours and 400 km) **

## MLS – Ny-Alesund (Spitzbergen) lidar    (within +/- 6 hours and 400 km) 

**Differences remain well below uncertainties and natural variability**
**Poor statistics**
**New version and updated lidar temperature dataset expected shortly**

**MLS – Ny-Alesund (Spitzbergen) lidar    ****(within +/- 6 hours and 400 km) **

## Conclusion

**All comparisons shown here seem to point towards a well defined pattern of systematic biases:**
**1. MLS v5.1 seems to be 1-3 K too warm in the stratosphere, 1-2 K too cold in the upper troposphere and 2-4 K too cold in the mesosphere**
**2. Observed biases are consistent with a slightly offset pressure registration (MLS shifted down?).**
**3. An upward shift of the MLS profiles (2-3% in pressure) reduces significantly the observed differences with all other instruments and models.**

**Future plans:**
**Use new MLS version 2 !**
**Extend comparisons to TES and HIRDLS datasets when available**
**Extend Aura-to-model comparisons to the entire globe, and to both NCEP and ECMWF models**