Review of ozone and temperature lidar validations performed within the framework of the Network for the Detection of Stratospheric Change.
The use of assimilation tools for satellite validation requires true estimates of the accuracy of the reference data. Since its inception, the Network for Detection of Stratospheric Change (NDSC) has provided systematic lidar measurements of ozone and temperature at several places around the world that are well adapted for satellite validations. Regular exercises have been organised to ensure the data quality at each individual site. These exercises can be separated into three categories: large scale intercomparisons using multiple instruments, including a mobile lidar; using satellite observations as a geographic transfer standards to compare measurements at different sites; and comparative investigations of the analysis software. NDSC is a research network, so each system has its own history, design, and analysis, and has participated differently in validation campaigns. There are still some technological differences that may explain different accuracies. However, the comparison campaigns performed over the last decade have always proved to be very helpful in improving the measurements. To date, more efforts have been devoted to characterising ozone measurements than to temperature observations. The synthesis of the published works shows that the network can potentially be considered as homogeneous within +/-2% between 20-35 km for ozone and +/-1 K between 35-60 km for temperature. Outside this altitude range, larger biases are reported and more efforts are required. In the lower stratosphere, Raman channels seem to improve comparisons but such capabilities were not systematically compared. At the top of the profiles, more investigations on analysis methodologies are still probably needed. SAGE II and GOMOS appear to be excellent tools for future ozone lidar validations but need to be better coordinated and take more advantage of assimilation tools. Also, temperature validations face major difficulties caused by atmospheric tides and therefore require intercomparisons with the mobile systems, at all sites.
Keckhut
Philippe
P
Service d'Aéronomie/IPSL, Verrière-le-Buisson, France.
McDermid
Stuart
S
Swart
Daan
D
McGee
Thomas
T
Godin-Beekmann
Sophie
S
Adriani
Alberto
A
Barnes
John
J
Baray
Jean-Luc
JL
Bencherif
Hassan
H
Claude
Hans
H
di Sarra
Aleide G
AG
Fiocco
Georgio
G
Hansen
Georg
G
Hauchecorne
Alain
A
Leblanc
Thierry
T
Lee
Choo Hie
CH
Pal
Shiv
S
Megie
Gerard
G
Nakane
Hideaki
H
Neuber
Roland
R
Steinbrecht
Wolfgang
W
Thayer
Jeffrey
J
D000393:Air Pollutants / Q000032:analysis*; D008027:Light; D010083:Oxidants, Photochemical / Q000032:analysis*; D010126:Ozone / Q000032:analysis*; D011786:Quality Control; D012016:Reference Values; D012680:Sensitivity and Specificity; D012984:Software; D018531:Spacecraft; D013696:Temperature
D000393:Air Pollutants; D010083:Oxidants, Photochemical; D010126:Ozone