We review the characteristics of sea level variability at the coast focussing on how it differs from the variability in the nearby deep ocean. Sea level variability occurs on all timescales, with processes at higher frequencies tending to have a larger magnitude at the coast due to resonance and other dynamics. In the case of some processes, such as the tides, the presence of the coast and the shallow waters of the shelves results in the processes being considerably more complex than offshore. However, 'coastal variability' should not always be considered as 'short spatial scale variability' but can be the result of signals transmitted along the coast from 1000s km away. Fortunately, thanks to tide gauges being necessarily located at the coast, many aspects of coastal sea level variability can be claimed to be better understood than those in the deep ocean. Nevertheless, certain aspects of coastal variability remain under-researched, including how changes in some processes (e.g., wave setup, river runoff) may have contributed to the historical mean sea level records obtained from tide gauges which are now used routinely in large-scale climate research.

[1] The baroclinic structure of the Brazil Current(BC)-Intermediate Western Boundary Current (IWBC) at 22°-23°S was investigated. A reanalysis of the pioneer velocity profile measurements of the TRANSCOBRA Experiment [Evans and Signorini, 1985] revealed that the BC-IWBC system is about 75-80% baroclinic. Mapped velocity structure showed flow reversal at about 450 m, an IWBC thickness of 1200 m and core velocities exceeding 0.30 m s À1 . Total (baroclinic) transports for BC (southwestwards) and IWBC (northeastwards) were 5.6 (4.2) Sv and 3.6 (4.1) Sv, respectively. The strong baroclinic character of the BC-IWBC system and the lack of direct velocity observations in the area yielded us to propose the use of the cross-shelf version of the Princeton Ocean Model to generate absolute baroclinic velocities from hydrographic data. These velocities presented a similar reversal depth, and the transports of about 6 -7 Sv for both BC-IWBC were also comparable to values reported in the literature.

South of Australia, the monthly mean wind stress curl is positive during both summer and winter and leads to Ekman pumping and downwelling throughout the region. Sverdrup dynamics indicates that this downwelling should lead to a northward transport of around 5–10 Sv (1 Sv = 10 m3 s−1). Classical arguments for western boundary currents are adapted to show that this transport should be deflected into an upwelling favorable boundary current that flows from east to west along Australia's southern shelves: the Flinders Current. Support for this proposition is obtained from results of the Ocean Circulation and Climate Advanced Modelling project (OCCAM), Sverdrup transports, and limited observations for the region. In addition, the OCCAM results show that the northward transport leads to upwelling at depths below 400 m and that the Flinders Current (1) intensifies from Victoria to Western Australia (transport ∼8 Sv with speeds up to 15 cm s−1), (2) can extend from the surface to depths of 800 m, and (3) is found during both summer and winter. During winter the winds are downwelling favorable and lead to a coastal current that flows from west to east and opposes the Flinders Current. Further support for the origin and nature of the Flinders Current is obtained from simple numerical experiments made using a rectangular domain and idealized representations of the summer and winter wind stress.

ABSTRACT. Based on a vast set of in situ data, a first comprehensive overview of the oceanographic characteristics of Baía de Todos os Santos (BTS) is provided.BTS is the second largest coastal bay in Brazil (maximum area of 1223 km 2 and average depth of 9.8 m), and is located in the northeast Brazil, in the vicinity of Salvador city. The circulation inside the bay is mostly tidally driven and does not vary significantly throughout the year. On the other hand, the wet (winter) and dry (summer) seasons does alter significantly the distribution of water properties inside the BTS. During summer, the waters inside the bay have oceanic characteristics, with Tropical Water (TW) penetrating along the whole region, except for the mouth of Rio Paraguaçu. The water temperature inside the bay is higher than in the coastal zone, and variations can be up to 3 • C, reaching a maximum of nearly 30 • C. During winter, with the increase of freshwater inflow, salinity variations of about 4 are observed between the innermost stations inside BTS and the adjacent coastal region. Salinity values inside the bay can be as low as 32.3, inhibiting the penetration of TW into the BTS, which is totally occupied by a locally formed Coastal Water (CW). An evaluation of the flushing time is also provided and shows that during summer, a 60-fold increase can be observed compared to winter (38 days). While the circulation does not vary seasonally inside the bay, the associated inner shelf is characterized by two different scenarios. During summer, the upwelling favorable easterlies drive a southwestward flow, while during winter the more frequent occurrence of cold fronts (southerly winds) tend to reverse the circulation.Keywords: Baía de Todos os Santos, circulation, tides, water masses. RESUMO.Com base em um amplo conjunto de dados in situ, este artigo apresenta uma primeira caracterização oceanográfica da Baía de Todos os Santos. A BTSé a segunda maior baía costeira do Brasil (área máxima de 1223 km 2 e profundidade média de 9,8 m), e está localizada na região nordeste do Brasil, nas proximidades da cidade de Salvador. A circulação no interior da baíaé predominantemente forçada pelas marés e não varia significantemente ao longo do ano. Por outro lado, as estações chuvosa (inverno) e seca (verão) geram uma alteração significativa nas propriedades daságuas no interior da BTS. Durante o verão, aságuas dentro da baía têm características oceânicas, com aÁgua Tropical (AT) penetrando ao longo de toda a região, com exceção da desembocadura do Rio Paraguaçu. A temperatura dá agua dentro da baíaé maior do que a da região costeira adjacente, e estas variações podem ser de até 3 • C, atingindo um máximo de 30 • C. Durante o inverno, com o aumento do aporte deágua doce, variações de salinidade de cerca de 4 podem ser observadas entre a parte mais interna da BTS e a região costeira adjacente. Valores de salinidade dentro da baía podem chegar até 32,3, inibindo a penetração da AT dentro da BTS, que fica totalmente ocupada por umaágua costeira formada local...