1. Report on the atmospheric lidar observatory in McMurdo and Dome C
M.Snels
Istituto di Scienze dell’Atmosfera e del Clima, CNR, Roma

2. McMurdo LIDAR system 2004-2010 Compact NdYAG laser
532 nm (190 mJ/pulse)
1064 nm (90 mJ/pulse)
14” telescope (35.6 cm)
New optical box
400 Hz
Photon counting
Miniature photomultipliers (Hamamatsu)
Low/high 532 nm
1064 nm channel (APD)
Raman channel (607.3 nm)
Photon counting acquisition cards
(2*2048 bins,
Photon - counting , 100 ns bins, 250 MHz
Analog operation (not used) 80 MHz, 8 bit

3. Lower Troposphere Channel (1 km- 30 km) Nikon 50mm f/1
Lower Troposphere Channel (1 km- 30 km) Nikon 50mm f/ mm pinhole Hamamatsu PM

4. McMurdo science
The McMurdo data ( ) have been reclassified by using an approach very similar to the V2 detection and classification scheme for CALIOP.
This allows for a statistical comparison between ground based and satellite based observations of PSCs at McMurdo.
Coincident lidar and OPC observations of PSCs have been analyzed in order to obtain an empirical relation between the backscatter coefficient and the Surface Area Density (SAD) and Volume density (VD) of PSCs

5. Comparison CALIOP vs groundbased McMurdo (2006 June- September)
Blue = ice
Green = NAT mixtures
Red = enhanced Nat mix
Orange= STS

6. Comparison CALIOP vs groundbased McMurdo (2006-2010)
Vertical distribution
Relative abundances PSC types
PSC type
McMurdo gb [%]
McMurdo CALIOP [%]
STS
25.3
24.1
NAT mixtures
58.4
54.9
Enhanced NAT Mix
2.9
5.6
Ice
13.4
15.3
Blue = ice
Green = NAT mixtures
Red = enhanced Nat mix
Orange= STS

7. Dome C lidar observatory 2014-now
Status (1):
The data are of an excellent quality and coverage, due to upgrade of the system and more favorable conditions at Dome C (wrt McMurdo)
A new data acquisition system has been implemented since January 2018
The effect of the view window on the depolarization has been extensively characterized and a correction has been applied to the data.
The remote control of the lidar (from the main buildings at Dome C and from Rome) has been fully exploited now.

8. Dome C lidar observatory
Status (2):
All data ( ) have been uploaded to the NDACC data base.
This year we have a critical situation, because the laser needs a revision and the spare laser is unrepairable.
Funding is guaranteed for another two years at least.
A request for a new laser has been approved by PNRA and this will allow us to substitute the old laser in January 2019, and send the old laser to Europe for reconditioning and use it as a working spare from 2020

9. Dome C lidar observatory
Science:
The Dome C data are being reclassified with an algorithm similar to the CALIOP V2 algorithm and compared with CALIOP data in a ± 2 degrees square around the Dome C coordinates.

10. Dome C vs CALIOP 2014-2017 (preliminary analysis)
PSC type
Dome C gb [%]
Dome C
CALIOP [%]
STS
34.5
22.6
NAT mixtures
45.7
49.4
Enhanced NAT Mix
5.6
6.8
Ice
14.2
21.1
Blue = ice
Green = NAT mixtures
Red = enhanced Nat mix
Orange= STS

11. Dome C vs CALIOP 2014 (preliminary analysis)

12. Dome C vs CALIOP 2015 (preliminary analysis)

13. Dome C vs CALIOP 2016 (preliminary analysis)

14. Papers to be submitted
Marcel Snels*, Francesco Cairo, Luca Di Liberto, Andrea Scoccione, Marco Bracaglia and Terry Deshler “Comparison of coincident optical particle counter and lidar measurements at McMurdo “ to be submitted to JGR
Marcel Snels*, Francesco Colao, Francesco Cairo, Andrea Scoccione, Mauro De Muro, and Michael Pitts, «Polar Stratospheric Cloud observations from Dome C (Antarctica) from 2014 to 2017“ to be submitted…
Marcel Snels*, Federico Fierli, Francesco Cairo, Luca Di Liberto, Michael Pitts, Chiara Cagnazzo, Andrea Scoccione, Terry Deshler, “Comparison of Antarctic polar stratospheric clouds observations by ground- and satellite based lidars and relevance for Chemistry Climate Models», to be submitted to ACP
* corresponding author

15. SAD and VD vs beta