Identification

Title

WACCM-D-Improved modeling of nitric acid and active chlorine during energetic particle precipitation

Abstract

Observations have shown that a number of neutral minor species are affected by energetic particle precipitation (EPP) and ion chemistry (IC) in the polar regions. However, to date the complexity of the ion chemistry below the mesopause (i.e., in the D region ionosphere) has restricted global models to simplified EEP/IC parameterizations which are unable to reproduce some important effects, e.g., the increase of mesospheric nitric acid (HNO3). Here we use WACCM-D, a variant of the Whole Atmosphere Community Climate Model which includes a selected set of D region ion chemistry designed to produce the observed effects of EPP/IC. We evaluate the performance of EPP/IC modeling by comparing WACCM-D results for the January 2005 solar proton event (SPE) to those from the standard WACCM and Aura/Microwave Limb Sounder (MLS) and SCISAT/Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) observations. The results indicate that WACCM-D improves the modeling of HNO3, HCl, ClO, OH, and NOx during the SPE. Northern Hemispheric HNO3 from WACCM-D shows an increase by 2 orders of magnitude at 40-70km compared to WACCM, reaching 2.6ppbv, in agreement with the observations. For HCl and ClO, the improvement is most pronounced in the Southern Hemisphere at 40-50km where WACCM-D predicts a decrease of HCl and increase of ClO by 1.6% and 10%, respectively, similar to MLS data. Compared to WACCM, WACCM-D produces 25-50% less OH and 30-130% more NOx at 70-85km which leads to better agreement with the observations. Although not addressed here, longer-term NOx impact of ion chemistry could be important for polar stratospheric ozone and middle atmospheric dynamics.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7vq34cv

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

Begin position

End position

Dataset reference date

date type

publication

effective date

2016-09-16T00:00:00Z

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