Unpublished conference/Abstract (Scientific congresses and symposiums)Comparisons of long-term stratospheric nitric acid and hydrogen fluoride variations using satellite and ground-based measurements
Froidevaux, L.; Anderson, J.; Hannigan, J. et al.
2011 • Network for the Detection of Atmospheric Composition Change - Symposium celebrating 20 years of atmospheric research fostered by NDACC/NDSC observations
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Abstract :
[en] We investigate the long-term variations of stratospheric nitric acid
(HNO3) and hydrogen fluoride (HF), based on several satellite and
ground-based measurement records. We use results from the Upper
Atmosphere Research Satellite (launched in late 1991 and decommissioned
in late 2005), the Aura satellite (launched in summer 1991, with
on-going measurements), and the Atmospheric Chemistry Experiment Fourier
Transform Spectrometer (ACE-FTS) (from 2004 to present), in conjunction
with several long-term ground-based datasets from the Network for the
Detection of Atmosphere Composition Change (NDACC). In particular, we
investigate the time series of HNO3 and HF, using NDACC column data for
validation. We focus here on a few NDACC sites with long-term and
frequent measurements, namely the Jungfraujoch (45N, 8E), Lauder (45S,
170E), and Mauna Loa (20N, 204E) sites, where ground-based Fourier
Transform Infrared (FTIR) measurements have covered both the UARS and
Aura time periods (1991 to present). For HNO3, we investigate whether
there are indications of a systematic offset between the measurements by
the Microwave Limb Sounder (MLS) instruments aboard both UARS and Aura.
For hydrogen fluoride, the HALogen Occultation Experiment's HF time
series are connected to the ACE-FTS dataset, and we analyze the
correlation of this time series with the ground-based datasets. In
addition, model runs from the Whole Atmosphere Community Climate Model
(WACCM) and the TOMCAT/SLIMCAT model are used as part of the long-term
time series intercomparisons. We note that there is a significant time
gap in the HNO3 time series from the satellite measurements used here.
The long-term satellite datasets studied here include zonal average
Earth Science Data Records (ESDRs) being produced under the Global Ozone
Chemistry And Related trace gas Data records for the Stratosphere
(GOZCARDS) project, part of the NASA Making Earth Science data records
for Use in Research Environments (MEaSUREs) program. We also analyze
coincident-type measurements, for the comparisons between satellite and
ground-based observations.
