2012 MARS DUST STORM NONSENSE

       Figure 2A purports to show how pressure varied from the norm during a dust storm on Mars that reached neither Opportunity (it missed it by 840 miles), which had no pressures instruments, nor MSL Curiosity on the opposite side of the planet. Curiosity had the questionable Vaisala pressure transducer on board. The main problem here is the timing of the dust storm, and the paucity of data put out by JPL, the REMS Team and Ashima Research leading up to this graph. Before August 23, 2012 those responsible for weather reports from MSL issued a single report that graphed pressures for MSL Sols 9.5 to 13 only. The same report only graphed temperatures for MSL Sol 10 to 11.5. There were promises that more data like this would be published at the PDS site, but 4.5 months later these promises are unfilled, hinting at what looks very much like a cover-up. When Figure 2A is inserted onto Figure 3 in the area of the chart where the dust storm discussed in this page is located, we found that between the first report of the storm at Sol 102 on November 18 at Ls 208.8 and the last report at Sol 108 (Ls 213.1 on November 25), the REMS and Ashima daily weather reports had no data for Sol 103 (Ls 209.4 on November 19), Sol 104 (Ls 210 on November 20), and Sol 105 (Ls 210.6 on November 21).

       REMS revised its weather reports in the summer of 2013. As of April 30, 2014 REMS and Ashima differ on the critical period here as follows:

                  PRESSURE DATE REPORTS POSTED

              BY JPL (REMS) AND ASHIMA RESEARCH

                              ON 30 APRIL 2014

     NOTE: We are not sure if we played a role in driving Ashima Research out of the business of reporting on MSL weather, but after numerous critiques of their work that we published they pulled down their web site by early 2016.

       The data after then suggests a slow, steady increase pressure that would be indicated by Viking 2 results; but the key point here is that red curve on Figure 2A is based on what appears to be missing (and therefore imagined?) data. Note that Figure 2A does not actually name either the Sol of the blue or red curves. If the REMS Team has more data than it publishes, why is it hiding it? We can only conclude from what we see here for Figure 2A is not supported by data required.    

       Figure 2A has other major problems too. As is shown, Figure 2B is a near clone of the data presented for Sol 11, the only day that the REMS Team ever published a pressure graph and temperature graph for in the first 4.5 months of operation. The blue curve on Figure 2A appears to be taken from Figure 2B, but for that early period of MSL pressure reporting operations data was anything but fully stable. While the chart presented for sols 9.5 to 13 was consistent with respect to day to day operations; that ended very quickly. Sol 13 was on August 20, 2012. No pressure was originally published for Sol 14 (but a year later it was assigned a pressure of 7.4 hPa (740 Pa). On Sol 15 there was an original average pressure of 7.3 hPa (7.3 mbar) published, but it was changed almost a year later to 7.4 hPa. The only relative humidity ever published for MSL (7%) on Sol 15 was eliminated in revised reports next year. Sol 16 pressure was reported as 7.4 hPa. For the next two days (sols 17 and 18) no pressure was originally published, but a year later REMS claimed 7.42 hPA for sol 17. Sol 19 was interesting. Average pressure climbed to 7.85 hPa originally, but after we questioned it REMS changed it to N/A. Nothing was reported on August 26, but on August 27 (sol 21) it had originally risen to 7.9 hPa. Again, when we questioned this pressure because it was above the expected curve, the REMS Team dropped it back to 7.41 hPa.  With two original exceptions that vanished later, a  pressure of 7.9 hPa was not seen again on the typical pressure curve until Sol 74 on October 20, 2012. The two exceptions were also fairly early in MSL weather reports - 7.99 hPa (later dropped to 7.49 hPa) on Sol 35 (September 11) and 8.04 hPa (later dropped to 7.53 hPa) on Sol 40 (September 16). Clearly the REMS Team has been acting like slaves to the Viking pressure curves. They have consistently altered data to stick to those curves.  The data published by JPL is absolutely untrustworthy (with the possible exception of their original reports between September 1 and 5, 2012 that showed pressures between 742 hPa and 747 hPa (mbar) before they reduced it by changing hPa unist to Pa units. Thus 747 hPa became 7.47 hPa - which is like exchanging dollars for the same number of cents. The higher pressures match the weather plainly seen on Mars. While they might represent a rebellion in the REMS team where somebody wanted us to know the truth, it seems more likely that they were working with the same faulty transducer with a jammed dust filter, and that they merely used hPa units when they meant to use Pa which they did in fact use after this period of confusion.

       The bottom line on Figure 2A is that by no means was the pressure situation stabilized by this point in MSL operations to compare normal pressure cycles with dust pressure cycles; and even if it were the dust storm never reached MSL. Therefore Figure 2A is utter nonsense.

J. D. Parsons (2000) addresses the compressibility of dust storms and positive feedback for their formation.  Pre-dust storm density values are around 9.4 g/m³.  A sample dust storm given in Parsons paper would have additional densities of 17g/m³ in order to even be created.  This is an order of magnitude greater than terrestrial storms.  It also constitutes an increase of at least several hundred percent over previously accepted values.  In the Sahara, pressures have been observed to increase during dust storms.  Likewise when the huge dust storm hit Luke Air Force on July 5, 2011,  pressure rose by 6.6 mbar (more than accepted average pressure at Mars areoid) between the storm’s arrival at 0255Z 6 July 2011 (pressure 1004.7 mbar) and 0555Z when the pressure was up to 1011.3 mbar. Pressure dropped as visibility cleared at 0655Z (personal call to Luke AFB meteorology, July 6, 2011).

The Parsons (2000) paper proposes a gravity current analog for dust storms and mentions that such currents should be constrained to the height of the inversion layer (but dust storms on Mars can still have effects at 160 km). Perhaps most important, increased pressure makes it easier to entrain particles (hence higher pressure may explain dust storms and dust devils). During the Martian year opacity varies greatly.  The clear season is in the northern summer with optical depth τ values of ~0.3 to 0.5. During northern winter τ values of ~2 to 5 or higher were seen during dust storms (see Figure 7).  Black dots are the Year One data, black pluses are the Year Two data, and the red X’s are extrapolations from the pressure data. This is for Viking 1. There is a relation between pressure and opacity, however the figure adapted from page 181 in The Martian Climate Revisited by Read and Lewis, states that τ is derived from pressure data. This is the same pressure data that might be distorted by clogged pressure filters. There is a need to quantify how increased density and opacity due to dust storms affect pressure on Mars.