Identification

Title

Progress in observations and simulations of global change in the upper atmosphere

Abstract

Anthropogenic increases of greenhouse gases warm the troposphere but have a cooling effect in the middle and upper atmosphere. The steady increase of CO₂ is the dominant cause of upper atmosphere trends; other drivers are long-term changes of radiatively active trace gases such as CH₄, O₃, and H₂O, secular change of solar and geomagnetic activity, and evolution of the Earth's magnetic field. Observational and model studies have confirmed that in the past several decades, global cooling has occurred in the mesosphere and thermosphere; the cooling and contraction of the upper atmosphere has lowered the ionosphere and increased electron density in the E and F₁ regions. Trends of other parameters, including the F₂ region, mesospheric clouds, and mesopause wave activity, have been more controversial. Modeling investigations have demonstrated that both greenhouse gas forcing and secular change of the Earth's magnetic field can cause regional, diurnal, and seasonal variability of trends in F₂ region density and height, which may contribute to discrepancies regarding ionospheric trends. Recent studies also may have reconciled discrepancies between space-based and ground-based observations of mesospheric clouds: both types of observations do not find statistically significant trends in the ~54°N - ~64°N latitude region, but space-based observations indicate that clouds may be increasing in frequency at higher latitude. Limited observational studies have suggested possible trends in wave activity. Changes in atmospheric dynamics, both as a consequence of global change in the lower and middle atmosphere and as a possible driver of trends in the upper atmosphere, is one of the critical open questions regarding trends in the upper atmosphere and ionosphere.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d718373k

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

2011-04-13T00:00:00Z

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