Dayside electron temperature and density profiles at Mars : First results from the MAVEN Langmuir probe and waves instrument

We present Mars' electron temperature (T-e) and density (n(e)) altitude profiles derived from the MAVEN (Mars Atmosphere and Volatile EvolutioN) mission deep dip orbits in April 2015, as measured by the Langmuir probe instrument. These orbits had periapsides below 130 km in altitude at low solar zenith angles. The periapsides were above the peak in n(e) during this period. Using a Chapman function fit, we find that scale height and projected altitude of the n(e) peak are consistent with models and previous measurements. The peak electron density is slightly higher than earlier works. For the first time, we present in situ measurements of T-e altitude profiles in Mars' dayside in the altitude range from similar to 130 km to 500 km and provide a functional fit. Importantly, T-e rises rapidly with altitude from similar to 180 km to similar to 300 km. These results and functional fit are important for modeling Mars' ionosphere and understanding atmospheric escape.