A Climatology of Central American Gyres

A Climatology of Central American Gyres AbstractCentral American gyres (CAGs) are large, closed, cyclonic circulations that occur during the rainy season (May–November), which can yield exceptional rainfall leading to catastrophic flooding and large societal impacts. A reanalysis-based climatology of CAGs is developed from an algorithm that distinguishes CAG cases from other systems. This algorithm identified CAG cases based on circulation intensity, a broad radius of maximum winds, and the existence of closed, earth-relative, cyclonic flow. Based on these criteria, 47 CAG cases were identified from 1980–2010, featuring a bimodal distribution of cases with maxima in May–June and September–November.CAG cases are composited into two categories based on their uppertropospheric PV structure: non-baroclinic CAGs are more common (N = 42) and characterized by an upper-tropospheric anticyclone, while baroclinic CAGs are less common (N = 5) and characterized by an upper-tropospheric trough. Whereas a non-baroclinic CAG has anomalous moisture and precipitation surrounding the center, a baroclinic CAG has anomalous moisture and precipitation concentrated east of the center, with these structural differences attributed to their upper-tropospheric PV structure. Both non-baroclinic and baroclinic CAGs are preceded by anomalous westerly lower-tropospheric flow in the eastern Pacific before their development, which is linked to a climatological reduction in easterly trade-winds and is coincident with MJO phases 1, 2, and 8. Extreme precipitation is observed over multiple days in all available CAG cases, most commonly along the Central American coastline and on average over a large fractional area (25%) within 10 degrees of their center. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Monthly Weather Review American Meteorological Society

A Climatology of Central American Gyres

Loading next page...
 
/lp/ams/a-climatology-of-central-american-gyres-GsuG1iGeKM
Publisher
American Meteorological Society
Copyright
Copyright © American Meteorological Society
ISSN
1520-0493
eISSN
1520-0493
D.O.I.
10.1175/MWR-D-16-0411.1
Publisher site
See Article on Publisher Site

Abstract

AbstractCentral American gyres (CAGs) are large, closed, cyclonic circulations that occur during the rainy season (May–November), which can yield exceptional rainfall leading to catastrophic flooding and large societal impacts. A reanalysis-based climatology of CAGs is developed from an algorithm that distinguishes CAG cases from other systems. This algorithm identified CAG cases based on circulation intensity, a broad radius of maximum winds, and the existence of closed, earth-relative, cyclonic flow. Based on these criteria, 47 CAG cases were identified from 1980–2010, featuring a bimodal distribution of cases with maxima in May–June and September–November.CAG cases are composited into two categories based on their uppertropospheric PV structure: non-baroclinic CAGs are more common (N = 42) and characterized by an upper-tropospheric anticyclone, while baroclinic CAGs are less common (N = 5) and characterized by an upper-tropospheric trough. Whereas a non-baroclinic CAG has anomalous moisture and precipitation surrounding the center, a baroclinic CAG has anomalous moisture and precipitation concentrated east of the center, with these structural differences attributed to their upper-tropospheric PV structure. Both non-baroclinic and baroclinic CAGs are preceded by anomalous westerly lower-tropospheric flow in the eastern Pacific before their development, which is linked to a climatological reduction in easterly trade-winds and is coincident with MJO phases 1, 2, and 8. Extreme precipitation is observed over multiple days in all available CAG cases, most commonly along the Central American coastline and on average over a large fractional area (25%) within 10 degrees of their center.

Journal

Monthly Weather ReviewAmerican Meteorological Society

Published: Mar 3, 2017

There are no references for this article.

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off