Identification

Title

Analyzing dynamical circulations in the tropical tropopause layer through empirical predictions of cirrus cloud distributions

Abstract

We explore the use of nonlinear empirical predictions of thin cirrus for diagnosing transport through the tropical tropopause layer (TTL). Thirty day back trajectories are calculated from the locations of CALIPSO cloud observations to obtain Lagrangian dry and cold points associated with each observation. These historical values are combined with “local” (at the location of the CALIPSO observation) temperature and specific humidity to predict cloud probability using multivariate polynomial regression. We demonstrate that our statistical sample (seven seasons) is sufficient to retrieve the full nonlinear relationship between cloud probability and its predictors and that substantial information is lost in a purely linear analysis. The best cloud prediction is obtained by the two-variable combination of local temperature and humidity, which reflects the close relationship between clouds and relative humidity. However, single-variable predictions involving air parcel histories are better than those based solely on the individual local fields, indicating the existence of reliable dynamical information content within parcel trajectories. Thermal fields are better cirrus predictors during boreal winter than summer primarily due to poor predictions over the Asian summer monsoon region, revealing that the functional relationship over southern Asia differs from the rest of the tropics; in short, TTL cirrus formation over regions of active maritime convection, such as the West Pacific, is thermally dominated, indicating an environment in which in situ cirrus are readily formed, while TTL cirrus of southern Asia is moisture dominated, indicating a more direct connection between convective injection of moisture and thin cirrus.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d79z95v8

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

2014-03-27T00:00:00Z

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