Comparison of Antarctic polar stratospheric cloud observations by ground-based and space-borne lidar and relevance for chemistry–climate models
2018
Abstract. A comparison of polar stratospheric cloud (PSC) occurrence from 2006 to
2010 is presented, as observed from the ground-based lidar station at McMurdo
(Antarctica) and by the satellite-borne CALIOP lidar (Cloud-Aerosol Lidar
with Orthogonal Polarization) measuring over McMurdo. McMurdo (Antarctica) is
one of the primary lidar stations for aerosol measurements of the NDACC (Network for
Detection of Atmospheric Climate Change). The ground-based observations have
been classified with an algorithm derived from the recent v2 detection and
classification scheme, used to classify PSCs observed by CALIOP. A statistical approach has been used to compare ground-based and satellite-based observations, since point-to-point comparison is often troublesome due
to the intrinsic differences in the observation geometries and the imperfect
overlap of the observed areas. A comparison of space-borne lidar observations and a selection of simulations
obtained from chemistry–climate models (CCMs) has been made by using a series of
quantitative diagnostics based on the statistical occurrence of different PSC
types. The distribution of PSCs over Antarctica, calculated by several
CCMVal-2 and CCMI chemistry–climate models has been compared with the PSC
coverage observed by the satellite-borne CALIOP lidar. The use of several
diagnostic tools, including the temperature dependence of the PSC
occurrences, evidences the merits and flaws of the different models. The
diagnostic methods have been defined to overcome (at least partially) the
possible differences due to the resolution of the models and to identify
differences due to microphysics (e.g., the dependence of PSC occurrence on
T − T NAT ). A significant temperature bias of most models has been observed, as well as a
limited ability to reproduce the longitudinal variations in PSC occurrences
observed by CALIOP. In particular, a strong temperature bias has been observed
in CCMVal-2 models with a strong impact on PSC formation. The WACCM-CCMI
(Whole Atmosphere Community Climate Model – Chemistry-Climate Model
Initiative) model compares rather well with the CALIOP observations, although
a temperature bias is still present.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
50
References
11
Citations
NaN
KQI