A Shape Metric Methodology for Studying the Evolving Geometries of Synoptic-Scale Precipitation Patterns in Tropical Cyclones

Stephanie E. Zick and Corene J. Matyas

Annals of the American Association of Geographers, 2016, vol. 106, issue 6, 1217-1235

Abstract: A tropical cyclone (TC) is a cyclonic weather system with compact, centrally organized precipitation. As a TC transitions from a symmetric warm-core cyclone to an extratropical system, or as the TC dissipates, the weather system loses its characteristic central, symmetric qualities. In this article, we demonstrate a shape metric methodology that can be used to assess the overall evolution of and the spatiotemporal positions of significant changes to synoptic-scale precipitation structure. We first illustrate this methodology using three-hourly North American Regional Reanalysis (NARR) accumulated precipitation in Hurricane Katrina (2005) and then extend the analysis to all 2004 to 2015 U.S. landfalling TCs. To quantify the shape of the precipitation pattern, we construct a binary image by limiting the search radius to a distance of 600 km from the TC center and applying a minimum threshold based on the 90th percentile of precipitation observed within the search radius. Using the fundamental geographic concept of compactness, we formulate a suite of shape metrics that encompass the characteristic geometries of TCs moving into the midlatitudes: asymmetry, fragmentation, and dispersiveness. As we demonstrate with Hurricane Katrina, a moving Mann–Whitney U test reveals significant shape changes during the TC life cycle. These evolutionary periods correspond to structural changes observed by National Hurricane Center forecasters. Extending the analysis to all 2004 to 2015 storms, we observe increasing (decreasing) compactness in the eastern and central (western) Gulf of Mexico. Dispersiveness increases prior to landfall in most cases; however, asymmetry and fragmentation increase more commonly in western (vs. eastern) Gulf landfalls.

Date: 2016
References: Add references at CitEc
Citations: View citations in EconPapers (3)

Downloads: (external link)
http://hdl.handle.net/10.1080/24694452.2016.1206460 (text/html)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:taf:raagxx:v:106:y:2016:i:6:p:1217-1235

Ordering information: This journal article can be ordered from
http://www.tandfonline.com/pricing/journal/raag21

DOI: 10.1080/24694452.2016.1206460

Access Statistics for this article

Annals of the American Association of Geographers is currently edited by Jennifer Cassidento

More articles in Annals of the American Association of Geographers from Taylor & Francis Journals
Bibliographic data for series maintained by Chris Longhurst ().