English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The problem of optimal initial disturbances in thermal wind shear isrevisited and extended to include non-hydrostatic effects. This systematicstudy compares transient and modal growth rates of submesoscale instabilitiesover a large range of zonal and meridional wave numbers, aspect ratios, anddifferent Richardson number regimes. Selection criteria were derived to removespurious and unresolved instability modes that arise from the eigenvalueproblem and we generalize the study of the hydrostatic Eady problem by Heifetzand Farrell (2003, 2007, 2008) to thin fronts, characterized by large aspectratios. Such fronts are commonly found at the early stages of frontogenesis,for example, in the ocean mesoscale eddies and near the eye wall of hurricanes.In particular, we show that transient energy growth rates are up to two ordersof magnitude larger than modal counterparts for a wide range of Richardsonnumber and that the effects of transient energy gain become even greater whennon-hydrostatic effects become important and/or for large Richardson numbers.This study also compares the dominant energy pathways contributing to theenergy growth at short and long times. For symmetric modes, we recover theinertia-gravity instability described in Xu et al. (2007). These mechanisms areshown to be the most powerful mediator of vertical transport when compared withthe fastest growing baroclinic and symmetric modes. These results highlight theimportance of transient processes in the ocean and the atmosphere.

Transient energy growth in the ageostrophic Eady model