Mars Climate Sounder observations of wave structure in the North polar middle atmosphere of Mars during the summer season Paulina Wolkenberg1 and John Wilson2 1Centrum Badań Kosmicznych PAN 2NOAA Geophysical Fluid Dynamics Laboratory

Outline Characteristic features of Mars Climate Sounder Daytime and nighttime temperatures over North polar region T-average and T-difference fields Multi-track data Results and comparison with the GCM model Conclusions

Mars Climate Sounder nine broadband infrared channels in the range 0.3 – 45 mm vertical resolution 4 – 6 km vertical range 0 – 80 km 2 K error in the retrieval cross-track observations available

The red dots show the default 2x/sol coverage obtained with along-track viewing, while the blue dots show the additional coverage obtained with cross-track observations.

Daytime temperatures at 0.1 Pa Ls= 111-115 Ls= 133-137

Temperature: 60-65N Ls=100-110 T3pm T3am 0.1 Pa T3pm MY29-31 Longitude

m = 1 m = 2 m = 3 m = 4 Seasonal evolution of zonal wave components m = 1, m = 2, m = 3 and m = 4 derived from T3am at 60 – 65N. The interval in contour is 1K.

Evolution of the maximum amplitude of the zonal wave 2 component of T(3am) between 1 and 0.1 Pa. There are two maxima located between 20°N- 40°N and 60°N - 80°N centered at Ls = 90°. The interval in contour is 2 K. We’ll show that the northern peak is most likely a semi-diurnal tide, while the peak at 30N is due to an eastward propagating diurnal tide.

T-average field for Ls = 100 - 110 m=1 m=2 m=3 T-average field for Ls = 100 - 110 T-difference field for Ls = 100 - 110 (T3pm + T3am)/2 (T3pm – T3am)/2 Contributions from: stationary waves, non-migrating semidiurnal, migrating tides Contributions from: Diurnal non-migrating and migrating tides

m = 1 m = 2 m = 3 Amplitudes and phases of T- average (left) and T – difference (right) fields for m = 1 (top), m = 2 (middle) and m = 3 (bottom) at Ls = 100 - 110 and at 60 - 65N. The interval in contour is 1K. Locations of maxima correspond to wave phase at a particular pressure level. Phase for the m = 3 zonal wave of T – average is 75°E and is tilted eastward between 10Pa and 0.01Pa. Phase for the m = 3 of T – difference is 60°E.

Zonal wave components in a function of LT Zonal wave components in a function of LT. Amplitude maxima appear at different longitudes for different LT. This means that stationary waves are not responsible for this structure, only non-migrating and migrating tides.

Particular tides after the analysis of multi-track data at Ls = 101 – 114 and at 0.1Pa. Diurnal tides 55 – 60N 57.5N-62.5N 60-65N Semidiurnal tides 55 - 60N 57.5N – 62.5N 60 – 65N A1,1 8.5 K 8.0 K 9.9 K A1,2 m=1 1.4 K 1.5 K 3.0 K A-1,1 m=2 2.3 K 2.1 K 4.1 K A-1,2 m=3 3.7 K 1.9 K A2,1 m=1 0.2 K 0.4 K 1.6 K A2,2 5.5 K 4.5 K 2.2 K A-2,1 m=3 2.0 K 1.0 K A-2,2 m=4 0.7 K 0.3 K 1.7 K A3,1 m=2 0.6 K A3,2 m=1 1.1 K A-3,1 m=4 1.3 K A-3,2 0.0 K A4,1 m=3 0.9 K 0.8 K A4,2 m=2 0.1 K A-4,1 A-4,2 A0,1 m=1 A0,2 m=2 1.8 K 4.3 K (DW1) (SW1) (DE1) (SE1) (DW2) (SW2) (DE2) (SE2) (DW3) (SW3) (DE3) (DW4) (SW4) (D0) (S0)  

Simulated NonMigrating Tides Ls= 105 Results from MCS data at 60N A0,2 = 4.3 K m=2 A0,1 = 1.5 K m=1 A-1,1 = 4.1 K m=2 A-2,1 = 2 K m=3 A-3,1 = 1.6 K m=4 A-1,2 = 4.1 K m=3 Latitude Latitude

Conclusions Diurnal components of migrating tides dominate at 0.1 Pa over the semidiurnal one in the temperature field The m = 2 wave structure is due to A0,2 (S0) with 4.3 K and A-1,1 (DE1) with 4.1 K while the m = 3 structure is due to A-2,1 (DE2) with 2 K and A-1,2 (SE1) with 4.1 K Results are in an agreement with the GCM model