Identification

Title

Measuring and modeling the rate of separator reconnection between an emerging and an existing active region

Abstract

Magnetic reconnection occurs when new flux emerges into the corona and becomes incorporated into the existing coronal field. A new active region (AR) emerging in the vicinity of an existing AR provides a convenient laboratory in which reconnection of this kind can be quantified. We use high time-cadence 171 angstrom data from Solar Dynamics Observatory (SDO)/AIA, focused on new/old active region pair 11147/11149, to quantify reconnection. We identify new loops as brightenings within a strip of pixels between the regions. This strategy is premised on the assumption that the energy responsible for brightening a loop originates in magnetic reconnection. We catalog 301 loops observed in the 48 hr time period beginning with the emergence of AR 11149. The rate at which these loops appear between the two ARs is used to calculate the reconnection rate between them. We then fit these loops with magnetic field, solving for each loop's field strength, geometry, and twist (via its proxy, coronal alpha). We find the rate of newly brightened flux overestimates the flux that could be undergoing reconnection. This excess can be explained by our finding that the interconnecting region is not at its lowest energy (constant-alpha) state; the extrapolations exhibit loop-to-loop variation in alpha. This flux overestimate may result from the slow emergence of AR 11149, which allows time for Taylor relaxation internal to the domain of the reconnected flux to bring the a distribution toward a single value, providing another mechanism for brightening loops after they are first created.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d73j3h55

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

2019-12-17T00:00:00Z

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