climatology

Energy and momentum deposition from planetary-scale Rossby waves as well as from small-scale gravity waves (GWs) largely control stratospheric dynamics. Interactions between these different wave types, however, complicate the quantification of their individual contribution to the overall dynamical state of the middle atmosphere. In state-of-the-art general circulation models (GCMs), the majority of the GW spectrum cannot be resolved and therefore has to be parameterised. This is commonly implemented in two discrete schemes, one for GWs that originate from flow over orographic obstacles and one for all other kinds of GWs (non-orographic GWs). In this study, we attempt to gain a deeper understanding of the interactions of resolved with parameterised wave driving and of their influence on the stratospheric zonal winds and on the Brewer–Dobson circulation (BDC). For this, we set up a GCM time slice experiment with two sensitivity simulations: one without orographic GWs and one without non-orographic GWs. Our findings include an acceleration of the polar vortices, which has historically been one of the main reasons for including explicit GW parameterisations in GCMs. Further, we find inter-hemispheric differences in BDC changes when omitting GWs that can be explained by wave compensation and amplification effects. These are partly evoked through local changes in the refractive properties of the atmosphere caused by the omitted GW drag and a thereby increased planetary wave propagation. However, non-local effects on the flow can act to suppress vertical wave fluxes into the stratosphere for a very strong polar vortex. Moreover, we study mean age of stratospheric air to investigate the impact of missing GWs on tracer transport. On the basis of this analysis, we suggest that the larger ratio of planetary waves to GWs leads to enhanced horizontal mixing, which can have a large impact on stratospheric tracer distributions

Climate change exacerbates hurricane flood hazards along US Atlantic and Gulf Coasts in spatially varying patterns

One of the most destructive natural hazards, tropical cyclone (TC)–induced coastal flooding, will worsen under climate change. Here we conduct climatology–hydrodynamic modeling to quantify the effects of sea level rise (SLR) and TC climatology change (under RCP 8.5) on late 21st century flood hazards at the county level along the US Atlantic and Gulf Coasts. We find that, under the compound effects of SLR and TC climatology change, the historical 100-year flood level would occur annually in New England and mid-Atlantic regions and every 1–30 years in southeast Atlantic and Gulf of Mexico regions in the late 21st century. The relative effect of TC climatology change increases continuously from New England, mid-Atlantic, southeast Atlantic, to the Gulf of Mexico, and the effect of TC climatology change is likely to be larger than the effect of SLR for over 40% of coastal counties in the Gulf of Mexico.National Science Foundation (U.S.) (Grant EAR-1520683

Carolina CoCoRaHS

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities

Carolina CoCoRaHS

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities

Carolina CoCoRaHS

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities

South Carolina CoCoRaHS rain gauge gazette

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities

Carolina CoCoRaHS

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities

Carolina CoCoRaHS

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities

South Carolina CoCoRaHS rain gauge gazette

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities

Carolina CoCoRaHS

The South Carolina Community Collaborative Rain, Hail, and Snow Network regularly publishes a newsletter from the South Carolina State Climatology Office that covers drought, hurricane, and rainfall. CoCoRaHS is a grassroots volunteer network of backyard weather observers of all ages and backgrounds working together to measure and map precipitation in their local communities