The impact of the initial flow on the extratropical response to Madden-Julian oscillation convective heating

Michael Goss, Steven B. Feldstein

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The response to the Madden-Julian oscillation (MJO) over the Pacific-North American (PNA) region is investigated. In addition, the sensitivity of this response to the interaction between Madden-Julian oscillation forcing and the extratropical initial flow is explored. First, a simple dynamical model is run with an ensemble of 100 randomly selected initial conditions from ERA-Interim data, with no heating, MJO phase-1-like heating, and MJO phase-5-like heating. The 300-hPa geopotential height field is separated into a part that would evolve without an active MJO present, and a part that is a consequence of the MJO heating.Anegative 300-hPa geopotential height anomaly centered over northeastern China bounded by positive anomalies on its equatorward and poleward flanks is found to be followed by a large amplitude negative PNA-like response for MJO phase 1 and a positive PNA-like response for phase 5. A similar study is carried out using observational data. An analog approach-using projections to determine the analogs-is used to approximate the part of the flow that results from the MJO heating. The composite initial flow that corresponds to a large MJO response in observational data somewhat matches that in the model, although there is more variability between phases. Finally, the analog method is used to examine questions related to predictability and the MJO. It is found that predictability is improved by taking into account the presence of the MJO and by choosing analogs with high projections. The presence of an active MJO also increases predictability.

Original languageEnglish (US)
Pages (from-to)1104-1121
Number of pages18
JournalMonthly Weather Review
Volume143
Issue number4
DOIs
StatePublished - Jan 1 2015

Fingerprint

Madden-Julian oscillation
heating
geopotential
anomaly

All Science Journal Classification (ASJC) codes

  • Atmospheric Science

Cite this

@article{2c580e383f474d219edf67afa24f4739,
title = "The impact of the initial flow on the extratropical response to Madden-Julian oscillation convective heating",
abstract = "The response to the Madden-Julian oscillation (MJO) over the Pacific-North American (PNA) region is investigated. In addition, the sensitivity of this response to the interaction between Madden-Julian oscillation forcing and the extratropical initial flow is explored. First, a simple dynamical model is run with an ensemble of 100 randomly selected initial conditions from ERA-Interim data, with no heating, MJO phase-1-like heating, and MJO phase-5-like heating. The 300-hPa geopotential height field is separated into a part that would evolve without an active MJO present, and a part that is a consequence of the MJO heating.Anegative 300-hPa geopotential height anomaly centered over northeastern China bounded by positive anomalies on its equatorward and poleward flanks is found to be followed by a large amplitude negative PNA-like response for MJO phase 1 and a positive PNA-like response for phase 5. A similar study is carried out using observational data. An analog approach-using projections to determine the analogs-is used to approximate the part of the flow that results from the MJO heating. The composite initial flow that corresponds to a large MJO response in observational data somewhat matches that in the model, although there is more variability between phases. Finally, the analog method is used to examine questions related to predictability and the MJO. It is found that predictability is improved by taking into account the presence of the MJO and by choosing analogs with high projections. The presence of an active MJO also increases predictability.",
author = "Michael Goss and Feldstein, {Steven B.}",
year = "2015",
month = "1",
day = "1",
doi = "10.1175/MWR-D-14-00141.1",
language = "English (US)",
volume = "143",
pages = "1104--1121",
journal = "Monthly Weather Review",
issn = "0027-0644",
publisher = "American Meteorological Society",
number = "4",

}

The impact of the initial flow on the extratropical response to Madden-Julian oscillation convective heating. / Goss, Michael; Feldstein, Steven B.

In: Monthly Weather Review, Vol. 143, No. 4, 01.01.2015, p. 1104-1121.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The impact of the initial flow on the extratropical response to Madden-Julian oscillation convective heating

AU - Goss, Michael

AU - Feldstein, Steven B.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - The response to the Madden-Julian oscillation (MJO) over the Pacific-North American (PNA) region is investigated. In addition, the sensitivity of this response to the interaction between Madden-Julian oscillation forcing and the extratropical initial flow is explored. First, a simple dynamical model is run with an ensemble of 100 randomly selected initial conditions from ERA-Interim data, with no heating, MJO phase-1-like heating, and MJO phase-5-like heating. The 300-hPa geopotential height field is separated into a part that would evolve without an active MJO present, and a part that is a consequence of the MJO heating.Anegative 300-hPa geopotential height anomaly centered over northeastern China bounded by positive anomalies on its equatorward and poleward flanks is found to be followed by a large amplitude negative PNA-like response for MJO phase 1 and a positive PNA-like response for phase 5. A similar study is carried out using observational data. An analog approach-using projections to determine the analogs-is used to approximate the part of the flow that results from the MJO heating. The composite initial flow that corresponds to a large MJO response in observational data somewhat matches that in the model, although there is more variability between phases. Finally, the analog method is used to examine questions related to predictability and the MJO. It is found that predictability is improved by taking into account the presence of the MJO and by choosing analogs with high projections. The presence of an active MJO also increases predictability.

AB - The response to the Madden-Julian oscillation (MJO) over the Pacific-North American (PNA) region is investigated. In addition, the sensitivity of this response to the interaction between Madden-Julian oscillation forcing and the extratropical initial flow is explored. First, a simple dynamical model is run with an ensemble of 100 randomly selected initial conditions from ERA-Interim data, with no heating, MJO phase-1-like heating, and MJO phase-5-like heating. The 300-hPa geopotential height field is separated into a part that would evolve without an active MJO present, and a part that is a consequence of the MJO heating.Anegative 300-hPa geopotential height anomaly centered over northeastern China bounded by positive anomalies on its equatorward and poleward flanks is found to be followed by a large amplitude negative PNA-like response for MJO phase 1 and a positive PNA-like response for phase 5. A similar study is carried out using observational data. An analog approach-using projections to determine the analogs-is used to approximate the part of the flow that results from the MJO heating. The composite initial flow that corresponds to a large MJO response in observational data somewhat matches that in the model, although there is more variability between phases. Finally, the analog method is used to examine questions related to predictability and the MJO. It is found that predictability is improved by taking into account the presence of the MJO and by choosing analogs with high projections. The presence of an active MJO also increases predictability.

UR - http://www.scopus.com/inward/record.url?scp=84947982679&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84947982679&partnerID=8YFLogxK

U2 - 10.1175/MWR-D-14-00141.1

DO - 10.1175/MWR-D-14-00141.1

M3 - Article

VL - 143

SP - 1104

EP - 1121

JO - Monthly Weather Review

JF - Monthly Weather Review

SN - 0027-0644

IS - 4

ER -