Identification

Title

Regional and seasonal trends in tropical ozone from SHADOZ profiles: Reference for models and satellite products

Abstract

Understanding lowermost stratosphere (LMS) ozone variability is an important topic in the trends and climate assessment communities because of feedbacks among changing temperature, dynamics, and ozone. LMS evaluations are usually based on satellite observations. Free tropospheric (FT) ozone assessments typically rely on profiles from commercial aircraft. Ozonesonde measurements constitute an independent data set encompassing both LMS and FT. We used Southern Hemisphere Additional Ozonesondes (SHADOZ) data (5.8°N-14°S) from 1998 to 2019 in the Goddard Multiple Linear Regression model to analyze monthly mean FT and LMS ozone changes across five well-distributed tropical sites. Our findings: (a) both FT (5-15 km) and LMS (15-20 km) ozone trends show marked seasonal variability. (b) All stations exhibit FT ozone increases in February-May (up to 15%/decade) when the frequency of convectively driven waves have changed. (c) After May, monthly ozone changes are both positive and negative, leading to mean trends of +(1-4)%/decade, depending on station. (d) LMS ozone losses reach (4-9)%/decade midyear, correlating with an increase in TH as derived from SHADOZ radiosonde data. (e) When the upper FT and LMS are defined by tropopause-relative coordinates, the LMS ozone trends all become insignificant. Thus, the 20-year decline in tropical LMS ozone reported in recent satellite-based studies likely signifies a perturbed tropopause rather than chemical depletion. The SHADOZ-derived ozone changes highlight regional and seasonal variability across the tropics and define a new reference for evaluating changes derived from models and satellite products over the 1998-2019 period.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7mk6hc0

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

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South bounding latitude

Temporal reference

Temporal extent

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End position

Dataset reference date

date type

publication

effective date

2021-11-27T00:00:00Z

Frequency of update

Quality and validity

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Conformity

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version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact