Identification

Title

Effect of trends of middle atmosphere gases on the mesosphere and thermosphere

Abstract

We conducted model simulations to examine how changes in concentration of radiatively active trace gases in the middle atmosphere affect long-term changes in the upper atmosphere. We focused our model study on the impact of increases in carbon dioxide (CO₂), methane (CH₄), and water vapor (H₂O), and decreases in ozone (O₃) between 1983 and 2003. We used both the National Center for Atmospheric Research Whole Atmosphere Community Climate Model and the Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model, global mean version, in this study. The model simulations indicate that CO2 is the main forcing mechanism of long-term changes in the thermsophere, with minor influences from O₃, CH₄, and H₂O. At 400 km altitude, global mean thermospheric neutral density decreased by ~4.5% due to CO2 forcing alone, whereas it decreased by ~4.8% due to the combined forcing from all four gases. O₃ depletion caused cooling in the stratosphere and mesosphere (maximum decrease of 0.5 K) due to reduced absorption of solar ultraviolet radiation, but had nearly no cooling effect in the thermosphere. However, due to thermal contraction in the stratosphere and mesosphere, O₃ depletion caused a small decrease in thermospheric neutral density of ~0.25%. Increases in both CH₄ and H₂O may slightly warm the upper mesosphere and thermosphere due to increased chemical heating and absorption of solar ultraviolet radiation.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7kw5gx5

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

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2013-06-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

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