[en] An atmospheric aluminum laser induced plasma is investigated by means of absorption and emission spectroscopies in the near ultraviolet range. The absorbed radiation is produced by a second aluminum laser induced plasma, which is generated at adjustable time delay. The measurements of both ground and resonant state number densities are derived from the fitting of the experimental 308.21 nm (²P_1/2⁰-²D_3/2) and 396.15 nm (²P_3/2⁰-²S_1/2) line absorption profiles on the numerical solution of the radiative transfer equation. Owing to the dominant role played by the Stark effect in the line broadening and shifting, the calculation also provides the evolution in time and in space of the free electron density along the line of sight. More classically, the same method is applied to the emission profiles which exhibit strong self-absorbed shapes. The reliability of the results derived from both absorption and emission experiments is analyzed and the origin of the asymmetric shape of the absorption lines is discussed