High quality
Marvellous show
Project progress
Request
Vesselpositions

The period between November 17th and 20th probably will be remembered by many of you for a long time, at least when you were sailing at the right longitude and  under clear skies. A real shower of falling stars, the famous Leonid-meteorswarm has come to reality for many of you.

Last September to many vessels a request has been sent to support the observing campaign about these meteor-display in the nights between 17 and 20 November. Just before the tiny extraterrestrial dustparticles entered earth’s atmosphere two reminder-messages has been sent to all vessels and that wasn’t a preach to deaf ears.

High quality

Now, when I write this small evaluation, it’s December 18th, exactly one month after the Leonid-outburst. At this moment observations from at least 40 vessels have been received. Some have sent more than once a day their recordings, some even every day between Nov. 16th and 20th. A preliminary view to the incoming observations could be described without any hesitation as SPLENDID! The quality of the observations is very good and almost every contribuant has used the proposed format for sending the meteor-counts.

Just because of the detailed information, both on meteor-counts and actual weatherconditions, a further computation of the meteoroid-distribution of these Leonidswarm could start now.

In the coming months all the observations will be used to construct a continuous intensity/time image through the whole observationperiod. Till now, mostly landbased expeditions, sampled their meteor-counts and constructed these intensity/time diagrams (in expertterminology Zenit-Hourly-Rate-diagrams). The lack of observations over the vast oceanregions, for instance the Pacific and Atlantic gave a rather undetailed activity-curve there. Now, with the contribution of the marine-observations, I am already sure that more details of the Leonid-dustdistribution could be obtained.

Naturally the main target of this project was to obtain more detail in the meteordistribution of the Leonidswarm in the whole observationtime but more than that another important item gives me very good feelings…. the enthusiasm of many masters, officers and crewmembers when they were eyewitness of the impressive meteor display. From some reports easily can be seen that these men/women have seen a rare and very remarkable celestial event. Some reports show an intensity of 10 meteors in 10 seconds.

Marvellous show

Especially parts of these ‘thrilling’ experiences popped up in the “Remarks” of the codeformat. A few I will
repeat here already:

• Master Schoolbraid of the Maracas Bay, sailing just near Cuba: Several members of the crew observed a magnificent display of the first band of the Leonid meteors. At 04.20 lt. (09.20z) The counts were around 10/15 per minute, by  09.40z the counts had increased to 25-30 per minute and frequency remained steady for about 40 minutes then decreasing as daylight emerged.
• Eef Willems (PDZS), just for the eastcoast of the US, in his observation at Nov. 18th: between 1009z and 1014z 38 meteors reported. In the next 15 minutes 68, highest count 5 meteors in 3 seconds. One ‘exploded’ behind the clouds! And so on and so on. A bit further to the east, aboard of  PDXQ, 2nd officer v.d. Jagt and 1st officer Armee reported 120 meteors between 0630z and 0930z.

For me personally it was a nice surprise to see that officer Armee now contributed to the meteor-project while I have met him several times during the 5-week periods aboard the former weathership Cumulus, at the Ocean Weather Station positions Mike (66N 02^E) and Lima (57N 20W). Willem, you and all the other sailors, thanks a lot for the very important contribution to this special Leonid-observing project.
In the near future a lot of computing has to be done. Than, probably near spring 2002, a complete result of this project will be released. It will be published in several magazines. Also on the Internet it could be found then through the following address (URL)  http://www.weerboek.nl (item Meteor-project or Meteors).

Project progress
Request
However most observations have been sent almost directly to PMO-De Bilt, it is still possible that data from some locations, as the Pacific Ocean, have dealt with some communication ‘problems’. To be sure that no valuable data will be lost, a request to all vessels will be done here:

In the list below, all callsigns/names of vessels have been put together with the data on which they provided observations. Sometimes on a certain date more than one observation has been received. If you discover that your vessel’s callsign is NOT on this list for a certain date that you have contributed your obs. please send your observation again. The best is to make a copy of the original note and send it by postal means to:
PMO-KNMI, Mr. J. Schaap, PO-box 201, 3730 AE De Bilt, The Netherlands. We will highly appreciate your action to send your observation again in order to complete the whole dataset.