Jeongbin Seo

Ulsan National Institute of Science and Technology

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Sarah M. Kang

Ulsan National Institute of Science and Technology

Dargan M. W. Frierson

University of Washington

Aiko Voigt

University of Vienna

L. Ruby Leung

Pacific Northwest National Laboratory

Sonali McDermid

New York University

Masakazu Yoshimori

The University of Tokyo

Francis Codron

Centre National de la Recherche Scientifique

Jeffrey A. Jonas

Columbia University

Michela Biasutti

Columbia University

Baek‐Min Kim

Pukyong National University

Cooperative Institutions

Columbia University

University of Washington

Lamont-Doherty Earth Observatory

NSF National Center for Atmospheric Research

Scripps Institution of Oceanography

Goddard Institute for Space Studies

Centre National de la Recherche Scientifique

Nanjing University

Princeton University

Bjerknes Centre for Climate Research

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

A model intercomparison of the tropical precipitation response to a CO₂ doubling in aquaplanet simulations

Geophysical Research Letters (2016)

Jeongbin Seo Sarah M. Kang Timothy M. Merlis

Abstract In the present‐day climate, the mean Intertropical Convergence Zone (ITCZ) is north of the equator. We investigate changes in the ITCZ latitude under global warming, using multiple atmospheric models coupled to an aquaplanet slab ocean. The reference climate, with a warmer north from prescribed ocean heating, is perturbed by doubling CO 2 . Most models exhibit a northward ITCZ shift, but the shift cannot be accounted for by the response of energy flux equator where the atmospheric energy transport ( F A ) vanishes. The energetics of the simulated circulation shifts are subtle: changes in the efficiency with which the Hadley circulation transports energy, the total gross moist stability (Δ m ), dominate over mass flux changes in determining δ F A . Even when δ F A ≈ 0, the ITCZ can shift significantly due to changes in Δ m , which have often been neglected previously. The dependence of ITCZ responses on δΔ m calls for improved understanding of the physics determining the tropical Δ m .

Intertropical Convergence Zone

Hadley cell

Walker circulation

Convergence zone

Energetics

10.1002/2016gl072347

Cite

Citations (25)

The tropical rain belts with an annual cycle and a continent model intercomparison project: TRACMIP

Journal of Advances in Modeling Earth Systems (2016)

Aiko Voigt Michela Biasutti Jacob Scheff Jürgen Bader Simona Bordoni

This paper introduces the Tropical Rain belts with an Annual cycle and a Continent Model Inter-comparison Project (TRACMIP). TRACMIP studies the dynamics of tropical rain belts and their response to past and future radiative forcings through simulations with 13 comprehensive and one simplified atmosphere models coupled to a slab ocean and driven by seasonally varying insolation. Five idealized experiments, two with an aquaplanet setup and three with a setup with an idealized tropical continent, fill the space between prescribed-SST aquaplanet simulations and realistic simulations provided by CMIP5/6. The simulations reproduce key features of present-day climate and expected future climate change, including an annual-mean intertropical convergence zone (ITCZ) that is located north of the equator and Hadley cells and eddy-driven jets that are similar to present-day climate. Quadrupling CO

Intertropical Convergence Zone

Hadley cell

Convergence zone

Annual cycle

Tropical Atlantic

Tropical climate

10.1002/2016ms000748

Cite

Citations (56)

Response of the intertropical convergence zone to zonally asymmetric subtropical surface forcings

Geophysical Research Letters (2015)

Tiffany A. Shaw Aiko Voigt Sarah M. Kang Jeongbin Seo

Abstract The energetic framework predicts no shift of the zonal mean Intertropical Convergence Zone (ITCZ) in response to zonally asymmetric forcings (zonal warming and cooling regions with zero zonal mean) assuming radiative feedbacks are linear. Here we show the ITCZ shifts southward in response to a zonally asymmetric forcing in the Northern Hemisphere subtropics in a slab ocean aquaplanet model. The southward shift is consistent with decreased zonal mean energy input to the atmosphere due to cloud radiative effect changes in the cooling region. When cloud‐radiative feedbacks are disabled the ITCZ shifts northward consistent with changes in the warming region where increased energy input via surface heat fluxes and stationary Rossby‐wave transport dominate. Competition between cooling and warming regions leads to changes in gross moist stability. Our results show rectification of zonally asymmetric forcings play an important role in zonal mean ITCZ dynamics and highlight the importance of assessing the momentum budget when interpreting ITCZ shifts.

Intertropical Convergence Zone

Hadley cell

Forcing (mathematics)

Convergence zone

Radiative Cooling

Radiative equilibrium

Momentum (technical analysis)

10.1002/2015gl066027

Cite

Citations (26)

Sensitivity of tropical responses to the latitudinal position of zonally asymmetric thermal forcing in an aqua-planet setting

2015 AGU Fall Meeting (2015)

Kiwoong Park Sarah M. Kang Jeongbin Seo

Forcing (mathematics)

Tropical Atlantic

Source

Cite

Citations (0)

Seasonal Dependence of the Effect of Arctic Greening on Tropical Precipitation

Journal of Climate (2015)

Sarah M. Kang Baek‐Min Kim Dargan M. W. Frierson Sujong Jeong Jeongbin Seo

Abstract This paper examines the seasonal dependence of the effect of Arctic greening on tropical precipitation. In CAM3/CLM3 coupled to a mixed layer ocean, shrub and grasslands poleward of 60°N are replaced with boreal forests. With darker Arctic vegetation, the absorption of solar energy increases, but primarily in boreal spring and summer since little insolation reaches the Arctic in boreal winter. The net energy input into the northern extratropics is partly balanced by southward atmospheric energy transport across the equator by an anomalous Hadley circulation, resulting in a northward shift of the tropical precipitation. In contrast, in boreal fall, the slight increase in insolation over the Arctic is more than offset by increased outgoing longwave radiation and reduced surface turbulent fluxes in midlatitudes, from the warmer atmosphere. As a result, the Northern Hemisphere atmosphere loses energy, which is compensated by a northward cross-equatorial atmospheric energy transport, leading to a southward shift of the tropical precipitation in boreal fall. Thus, although Arctic vegetation is changed throughout the year, its effect on tropical precipitation exhibits substantial seasonal variations.

Hadley cell

10.1175/jcli-d-15-0079.1

Cite

Citations (8)

Sensitivity of Intertropical Convergence Zone Movement to the Latitudinal Position of Thermal Forcing

Journal of Climate (2014)

Jeongbin Seo Sarah M. Kang Dargan M. W. Frierson

Abstract A variety of recent studies have shown that extratropical heating anomalies can be remarkably effective at causing meridional shifts in the intertropical convergence zone (ITCZ). But what latitudinal location of forcing is most effective at shifting the ITCZ? In a series of aquaplanet simulations with the GFDL Atmospheric Model, version 2 (AM2), coupled to a slab mixed layer ocean, it is shown that high-latitude forcing actually causes a larger shift in the ITCZ than when equivalent surface forcing is applied in the tropics. Equivalent simulations are run with an idealized general circulation model (GCM) without cloud and water vapor feedbacks, also coupled to an aquaplanet slab ocean, where the ITCZ response instead becomes weaker the farther the forcing is from the equator, indicating that radiative feedbacks must be important in AM2. In the absence of radiative feedbacks, the tendency for anomalies to decrease in importance the farther away they are from the equator is due to the quasi-diffusive nature of energy transports. Cloud shortwave responses in AM2 act to strengthen the ITCZ response to extratropical forcing, amplifying the response as it propagates toward the equator. These results emphasize the great importance of the extratropics in determining the position of the ITCZ.

Intertropical Convergence Zone

Extratropical cyclone

Forcing (mathematics)

Hadley cell

Convergence zone

Shortwave

10.1175/jcli-d-13-00691.1

Cite

Citations (78)