ORCID Profile
0000-0001-8036-0628
Current Organisation
University of Oxford
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Geophysical Union (AGU)
Date: 12-01-2021
DOI: 10.1029/2020GL090810
Publisher: American Geophysical Union (AGU)
Date: 27-08-2020
DOI: 10.1029/2020GL087910
Abstract: Storm tracks are a pivotal component in extratropical weather and climate. The sea surface temperature (SST) front in the midlatitude South Indian Ocean has been found to anchor the climatological core of the Southern Hemisphere (SH) storm tracks. However, on interannual‐to‐decadal timescales, observational and modeling evidence is presented here that the strengthened SST front in the midlatitude western South Atlantic (SA) can intensify the SH summer storm tracks by supplying more baroclinic energy, which overwhelms contributions from other oceanic frontal zones. Idealized experiments suggest that such a predominant impact on synoptic storms lies in the strengthened SA SST front acting in concert with the favorable thermal background produced in the presence of the Andes (i.e., enhancements of downstream low‐level temperature gradients and synoptic temperature variability). Our findings imply that oceanic variability in the western SA frontal zone could be a remote regulator of the SH extratropical summer climate variability.
Publisher: Springer Science and Business Media LLC
Date: 17-08-2021
Publisher: American Meteorological Society
Date: 05-2018
Abstract: Two-way coupling between sea surface temperature (SST) variations in the midlatitude southern oceans and changes of synoptic-scale (2–8 day) eddy activities in the lower and upper troposphere throughout the year is investigated based on lagged maximum covariance analysis using reanalysis datasets from 1951 to 2000. Results show a strong seasonal dependence of the coupling, as characterized by the most prominent one in austral midsummer (January). On one hand, SST variations in austral late spring (primarily October) are likely to influence storm tracks in the following January. That is, significant warm SST anomalies in the western midlatitude areas of South Atlantic and south Indian Ocean could result in the systematic strengthening of the low-level and upper-level eddy activities, which is presumably attributed to the coherent intensification of the SST front and the lower-tropospheric baroclinicity. Particularly, interannual variability (a spectral peak at 4 yr) of SST in the western midlatitude South Atlantic in October could play a predominant role in driving the corresponding variability of the Southern Hemisphere storm tracks three months later. The timing of the discernible response of storm tracks is also discussed based on the preliminary results of sensitivity experiments. On the other hand, the strengthened eddy activities in January continue to induce the dipolelike patterns of SST anomalies in the midlatitude southern oceans. Those SST response patterns are, to the first order, determined by changes of the net surface heat flux. The anomalous Ekman advections in part driven by the storm-track changes also contribute to SST anomalies in the southern subtropical South Atlantic and the western midlatitude South Pacific.
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2023
End Date: 2024
Funder: National Institute for Health Research
View Funded Activity