MLTCS Newsletter Dec. 1993

MEMO TO: MLTCS Colleagues

FROM: Alan Manson, Co-convenor with Jeff Forbes

You will have just received a post-summer newsletter, but a number of important thing have happened in the last month, that warrant this extra to Autumn/Spring newsletter. They have been stimulated by the October UARS-Dynamics Meeting. In future, I will probably not send a normal mailing for such a small communication, but rely upon the STEP Bulletin Board (to which this document will also go). Please tell me if you cannot reach that with your computer-system-environment, and I will send a small mailing to those people only.

A final repetition on the STEP B-B: with DECnet---SET HOST NSSDCA--- :without, but "internetted"---TELNET NSSDCA.GSFC.NASA.Gov--- (The fall newsletter had subsequent "steps" to take).

A) CAMPAIGNS for 1994.
          Feb. 7-16
          April 11-20
          June 7-16
          Aug. 9-18 MLTCS-6 Aug. 10-16 (ISR, MLT (optical, radar)
          Oct. 3-12
          Dec. 5-14
These are chosen to include the ISR observation days.

B) MLTCS involvement with CADRE. . The CADRE campaigns (David Fritts - Convenor) have primary emphasis upon the equatorial region. However the study of the tides/planetary waves there is enhanced by MLTCS observations; inparticular the modelling of these (Maura Hagan, Jeff Forbes) requires data from our extra tropical stations.

          . The campaigns have been/will be:
               Dec. '92/Jan. '93 (inparticular Jan 20-30, MLTCS-5)
               Oct. '93 (ALOAA - 93)
               Mar. and Aug. '94

For the new 1994, it would be desirable to run for the month, but I will give you dates when they arrive.

. Data: We are interested in the mean circulation and tides for these intervals, but also planetary wave activity. The most useful product for Maura is therefore monthly means and tidal fields. However, if there are strong trends in a month these should be noted eg."if the 2-d wave (or some other period) increases in magnitude during the month, and the corresponding mean winds are also shifted, it would be interesting to attempt to model that." Maura adds, "that observations will lead (her) modelling effort".

For the planetary waves, any output that you use locally for that would be helpful eg. monthly spectra. Chris and I would like to work that up as a global-mode analysis - as he did for several 2-d studies recently, (1991-1993). Please send a file of hourly mean values for circa 3hts near 90 km, for each of those months.

Of course you will note that MLTCS - 5, Jan. 20-30, 1993 is imbedded in this second CADRE interval, so you may wish to send that data at the same time ie/ means and tidal fits for MLTCS-5 also.

Also, please note that this CADRE analysis we are suggesting/requesting is additional/complementary to special studies that CADRE and David Fritts will organize. We will work, in particular with Maura and Jeff, but there will be co-ordination with David.

Please send all the data requested to Saskatoon where we will organize it for its various purposes.

C) MLTCS and UARS/HRDI-WINDII Dynamics

Many of us have been active in this fruitful collaboration. In fact UARS-Dynamics will be involved with the CADRE campaigns above.

Another element, is the study of the dynamical responses of the atmosphere to particle precipitation. Two intervals have been chosen for study: Oct. 30-Nov. 8, 1992, and (our favourite!) Jan. 21-31, 1993. To the delight of most of our ISR colleagues, a rather vigorous auroral disturbance occurred during the latter. Please look at these 2, for any indications of MLT response eg./ wind or tide or GW variabilites, radar scatter changes, optical data anomalies, and ionospheric radio absorption (this is a chance for colleagues who cannot normally contribute to MLTCS Campaigns with tides, etc., to provide data.) This then becomes a winter anomaly study.

The ISR community will be analyzing/assessing these in their own study groups; the contact for the UARS sub-committee looking at this would be Marvin Geller (please make that contact). For the MLT community, please send anything at all you have that appears interesting to Saskatoon, and Ron and I will organize it. This is a dynamical, chemical, auroral, magnetospheric study in the full spirit of STEP --- please join in!

Conclusion

The various studies described above would require a significant effort on your part, more so than the earlier LTCS or MLTCS Campaigns. However, the opportunities for significant science to be done are very high in these, due to the collaborations: MLTCS working with CADRE; specific modelling efforts; and UARS involvment. This is why we began STEP, and formed MLTCS within it. We hope you will set time aside for these activities and contribute data and results. Your subsequent interactions will be also significant once papers are prepared.

Sincerely,

A. Manson