Estimates of sea surface height changes in the Atlantic Ocean derived from TOPEX altimeter data are compared with dynamic height estimates from an ocean general circulation model which assimilates temperature data. There is generally good, basin-wide agreement in the annual phase and amplitude between the two data sets. In the tropics and in the subtropical gyres, spatially averaged time series of TOPEX and model dynamic height data are well correlated and have RMS differences of about 2 cm. In western boundary regions, correlations are weaker and RMS differences can be as large as 8--10 cm.