Gerd Krahmann

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The North Atlantic Oscillation is the dominant mode of atmospheric variability in the North Atlantic Sector. Basin scale changes in the atmospheric forcing significantly affect the oceans' properties and circulation. Part of the ocean's response is local and rapid (surface temperature, mixed layer depth, upper ocean heat content, surface Ekman transport,(More)
Numerical experiments are performed to examine the causes of variability of Atlantic Ocean SST during the period covered by the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis (1958–98). Three ocean models are used. Two are mixed layer models: one with a 75-m-deep mixed layer and the other with a(More)
The response of the Atlantic Ocean to North Atlantic Oscillation (NAO)-like wind forcing has been investigated using an ocean-only general circulation model coupled to an atmospheric boundary layer model. A series of idealized experiments was performed to investigate the interannual to multi-decadal frequency response of the ocean to a winter wind anomaly(More)
The Mediterranean Sea has been investigated intensively since the early nineties, using modern techniques and collaborative approaches. This overview summarizes some of the resulting advances that were made concerning the physical oceanography of the western Mediterranean. The water mass formation processes are now much better understood and have been(More)
A general circulation ocean model has been used to study the formation and propagation mechanisms of North Atlantic Oscillation (NAO)-generated temperature anomalies along the pathway of the North Atlantic Current (NAC). The NAO-like wind forcing generates temperature anomalies in the upper 440 m that propagate along the pathway of the NAC in general(More)
[1] The response of the Arctic Ocean sea ice system to Northern Annular Mode-like wind forcing has been investigated using an ocean/sea ice general circulation model coupled to an atmospheric boundary layer model. A series of idealized experiments was performed to investigate the Arctic Ocean’s response to idealized winter wind anomalies on interannual to(More)
Nitrous oxide (N2O) is a climate relevant trace gas, and its production in the ocean generally increases under suboxic conditions. The Atlantic Ocean is well ventilated, and unlike the major oxygen minimum zones (OMZ) of the Pacific and Indian Oceans, dissolved oxygen and N2O concentrations in the Atlantic OMZ are relatively high and low, respectively. This(More)
Numerical experiments are performed to examine the causes of variability of Atlantic Ocean SST during the period covered by the NCEP reanalysis (1958-1998). We use three ocean models. Two are mixed layer models, one with a 75m deep mixed layer and the other with a variable depth mixed layer. For both mixed layer models the ocean heat transports are assumed(More)
Hydrographic and tracer [chlorofluorocarbon (CFC), component F11] data in the tropical Atlantic off Brazil taken in spring 1994 are used to describe the development of the water mass characteristics of Antarctic Bottom Water (AABW) between 10°S and 11°N. To compute the AABW transports, geostrophic computations and directly measured velocity fields are(More)