A simplified general circulation model for a baroclinic ocean with topography. Part I: Theory, waves and wind-driven circulations

A new type of ocean circulation model is described and tested for various simplewind-driven circulation problems. The model resides on the vorticity balance ofthe depth averaged velocity and a hierarchy of balance equations for thevertical moments of baroclinic velocity and density, the lowest density momentbeing the baroclinic potential energy. The latter is the most importantdynamical link between the barotropic and the baroclinic motion in the presenceof a sloping topography. We derive a coupled hierarchy of tendency equations forthe potential energy and higher order density moments which, together withmoments for the baroclinic velocities and an appropriate truncation and thebarotropic vorticity balance yields in a simplified set of vertical integratedequations describing the BARotropic-Baroclinic-Interaction (BARBI) of motions inthe ocean. Using a numerical implementation of BARBI, idealized companionexperiments with a full primitive equation model (MOM) show that wavepropagation properties and baroclinic adjustments are correctly represented inBARBI in mid latitudes as well as in equatorial latitudes. Furthermore, a set ofexperiments with a realistic application to the Atlantic/Southern Ocean systemreadily reveals important aspects which have been previously reported by studiesof gyre circulations and circumpolar currents using full primitive equationmodels

The dynamical balance, transport and circulation of the Antarctic Circumpolar Current

The physical ingredients of the ACC circulation are reviewed. A picture of thecirculation is sketched by means of recent observations of the WOCE decade. Wepresent and discuss the role of forcing functions (wind stress, surfacebuoyancy flux) in the balance of the (quasi)-zonal flow, the meridionalcirculation and their relation to the ACC transport. Emphasis will be on theinterrelation of the zonal momentum balance and the meridional circulation, theimportance of diapycnal mixing and eddy processes. Finally, new model conceptsare described: a model of the ACC transport dependence on wind stress andbuoyancy flux, based on linear wave theory; and a model of the meridionaloverturning of the Southern Ocean, based on zonally averaged dynamics with eddyparameterization

H.W.M. Olbers measurements of air temperature in Bremen from 1803 to 1822

We rediscovered a temperature time series from Heinrich W. M. Olbers. Heinrich W. M. Olbers measured in Bremen, Sandstrasse 15, in Germany from 1803 to 1821 three times a day (7 am, 1-2 pm and 10 pm) the temperature at his window of his study, which is up to 16 m above the zero marking at the Weserbrücke. The temperature values from 1814 are missing. We got the temperature values from different sources in the Olbers estate. We calculated the daily mean and digitized it in various plots. A very small trend towards cooling is apparent in the data which might be insignificant. But a clear seasonal trend was identifiable: the late winter and the early spring were becoming warmer, while the summer and early autumn became cooler. The average temperature in Bremen was 8.3606 deg C at that time. Additionally we combined the newly discovered Heinrich W. M. Olbers temperature data and the Heinemann and Bätjer data to see whether there are great differences between these two time series. Although the temperatures of Heinrich W. M. Olbers are in general cooler than the Heinemann and Bätjer data they fit together