NSFGEO-NERC:Large-Scale Atmospheric Circulation Response to Oyashio Extension Frontal Variability
Lead Research Organisation:
Imperial College London
Department Name: Physics
Abstract
This joint proposal to U.S. National Science Foundation's Directorate for Geosciences and U.K. Natural
Environment Research Council aims to investigate how the Oyashio Extension frontal variability in the
Northwest Pacific Ocean influences the large-scale atmospheric circulation by accumulating the
interaction between the individual weather system and underlying ocean front. The atmospheric storm
track exhibits the local maximum strength in the Northwest Pacific over the strong ocean fronts driven by
collocated maximum baroclinicity, which is in turn maintained by huge heat and moisture supplied by the
ocean. While significant advances have been achieved in the past decade or so on our understanding of
ocean front's impact on the atmosphere for the mean climate, there are still many crucial questions yet to
be answered, especially related to impact of ocean frontal variability on the atmospheric circulation
variability. A particular goal of this proposal is to unveil the link between the local air-sea interaction in
weather scale near the Oyashio Extension and its cumulative impact on the large-scale atmospheric
circulation and climate variability. Specific emphases will be placed on the seasonality of this link by
contrasting the early and late winter, and also the asymmetry/nonlinearity in the large-scale atmospheric
response to warm and cold SST anomalies induced by a shift of the Oyashio Extension front to the north
and south, respectively. These challenging goals will be addressed by combining analyses of
observational and reanalysis datasets and targeted climate model experiments using the Variable
Resolution Community Atmosphere Model v.6 with Spectral Element dynamical-core, a state-of-the art
atmospheric general circulation model, which will be configured with a very high-resolution over the
North Pacific and lower resolution elsewhere globally to realistically simulate the frontal air-sea
interaction over the Oyashio Extension as well as the feedback with the large-scale circulation at a
manageable computational cost. Furthermore, the role of local ocean coupling will be investigated by
comparing the atmosphere-only simulations with those coupled to the 1-dimensional column ocean
model.
Environment Research Council aims to investigate how the Oyashio Extension frontal variability in the
Northwest Pacific Ocean influences the large-scale atmospheric circulation by accumulating the
interaction between the individual weather system and underlying ocean front. The atmospheric storm
track exhibits the local maximum strength in the Northwest Pacific over the strong ocean fronts driven by
collocated maximum baroclinicity, which is in turn maintained by huge heat and moisture supplied by the
ocean. While significant advances have been achieved in the past decade or so on our understanding of
ocean front's impact on the atmosphere for the mean climate, there are still many crucial questions yet to
be answered, especially related to impact of ocean frontal variability on the atmospheric circulation
variability. A particular goal of this proposal is to unveil the link between the local air-sea interaction in
weather scale near the Oyashio Extension and its cumulative impact on the large-scale atmospheric
circulation and climate variability. Specific emphases will be placed on the seasonality of this link by
contrasting the early and late winter, and also the asymmetry/nonlinearity in the large-scale atmospheric
response to warm and cold SST anomalies induced by a shift of the Oyashio Extension front to the north
and south, respectively. These challenging goals will be addressed by combining analyses of
observational and reanalysis datasets and targeted climate model experiments using the Variable
Resolution Community Atmosphere Model v.6 with Spectral Element dynamical-core, a state-of-the art
atmospheric general circulation model, which will be configured with a very high-resolution over the
North Pacific and lower resolution elsewhere globally to realistically simulate the frontal air-sea
interaction over the Oyashio Extension as well as the feedback with the large-scale circulation at a
manageable computational cost. Furthermore, the role of local ocean coupling will be investigated by
comparing the atmosphere-only simulations with those coupled to the 1-dimensional column ocean
model.
People |
ORCID iD |
| Arnaud Czaja (Principal Investigator) |