 |
| Titel |
SI2N assessment of vertical ozone trends: Stability of limb/occultation data records over 1984-2013 against ground-based networks |
| VerfasserIn |
Daan Hubert, Jean-Christopher Lambert, Tijl Verhoelst, José Granville, Arno Keppens |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250091387
|
| Publikation (Nr.) |
 EGU/EGU2014-5678.pdf |
|
|
|
|
|
| Zusammenfassung |
| Since the first indirect solar occultation measurement of the ozone profile with Echo-1 in
1960, numerous limb/occultation viewing instruments were deployed in space over the past
50 years to measure the vertical distribution of atmospheric ozone. Among them, a few
provided data records potentially suitable for documenting the evolution of the ozone layer
and for improving our understanding of the interactions between changes in ozone, climate,
and solar radiation. Three decades after the start of stratospheric ozone depletion by
man-made chemicals, the first weak signs of slow recovery in stratospheric ozone abundance
over Northern mid-latitudes were reported in the last WMO Ozone assessment, in 2010. The
data collected since then, together with recent improvements of historical data records, may
substantiate these initial findings and even provide hints as to how to attribute the
recovery of the ozone layer. In preparation of the upcoming WMO assessment in
2014, the ozone research community set up the SPARC/IO3C/IGACO-O3/NDACC
Initiative on Past Changes in the Vertical Distribution of Ozone (SI2N), to study and
document those long-term changes. To increase the significance of trend studies, ozone
records from measurement systems with different instrumental design and retrieval
technique were merged. As a prerequisite, the stability of and consistency between
these data records played a pivotal role in the SI2N effort and are the subject of this
report.
In this SI2N context, we present a comprehensive and systematic quality assessment of
the 14 major space-based limb and occultation ozone profile records potentially suitable for
ozone trend assessments, from the ground up to the middle stratosphere. All satellite records
were analysed within one methodological framework. Correlative ground-based observations
from the ozonesonde and lidar networks (NDACC, GAW) act as a reference standard
with well-characterized quality. The application of robust statistical methods and
various methodological cross-checks furthermore increases the reliability of this
assessment. We present estimates of the decadal drift, the bias, and the short-term
variability of each satellite record relative to the ground-based network data. The
dependence of these parameters on altitude and, whenever possible, on latitude
and season, is discussed as well. Particularly important in the data/trend merging
approach of SI2N are the conclusions on the consistency between records, and its
dependence on the specific coordinate system in which the ozone profile is represented. |
|
|
|
|
|
|