Introduction 
From January to March 1972 the German research vessels 
"Meteor" and "Planet" carried out Joint investigations 
("Auftrieb '72") in the Northwest African upwelling 
area off the coasts of Spanish Sahara and Mauretania, 
This volume contains data obtained during the two 
cruise legs of R.V. "Planet", Main objective of these 
measurements were to investigate : 
The mean circulation pattern and. its interactions 
with the density field 
The energetics of barotropic and baroclinic tidal 
motions above the continental sSlope with respect 
to their interactions and to their possible 
effects on the stratification, 
Leg I of the "Planet"-cruise was mainly devoted to a 
hydrographical survey (January 28 - February 8) along 
sections normal to the continental slope (page 21). 
Routine CTD's (Bathysonde) and hydrocasts were taken. 
The results are shown as sections and maps for tempe- 
rature, salinity and density (see pages 24 to 57). 
During leg II of the "Planet"-cruise (February 24 — 
March 15) work was centered around an array of 2 tide 
gauges (Graafen, Rauschelbach), 47 current meters 
(Aanderaa, Geodyne, Hydrowerkstätten) and 53 thermistor 
chains (Aanderaa), which were moored on the shelf and at 
the upper and lower slope region (page 58). 
Hydrographic data were repeatedl1y sampled at the 
positions of the moored instruments (pages 61 to 74). 
Time series and spectra of sea level temperature, and 
current components aswell as progressive vector 
diagrams are given at pages 75 - 115.