During the late Spring and early Summer of 1997, noctilucent clouds
(NLC) were monitored by several North American observers for the tenth
consecutive NLC CAN AM surveillance network season. Participants
included 17 amateur observers and 8 Canadian flight service and weather
stations where staff watched on a voluntary basis.

Sightings are listed in Table 1. A total of 34 nights experienced NLC
activity, compared with 24 active nights recorded in 1996. Synoptic
data from participants observing through the entire season indicate that
overall activity remains strong, a trend which began in 1995 and which
appeared to continue in 1996 based again on synoptic NLC CAN AM data.

The NLC season began with a couple of displays noted at the very end of
May, the earliest being seen by Richard Huziak on May 29/30. A possible
sighting, again by Huziak, was recorded on May 11/12. Near-consecutive
night activity began, as was the case in 1996, rather abruptly in early
June. Incidence remained robust until the end of June, but then
subsided somewhat at the beginning of July. The midpoint of the month
of July was punctuated by a flurry of activity, with some observers
seeing NLC on four consecutive nights, Jul 12/13 through to the 15/16.
Thereafter, incidence dropped sharply, except for a four-night outbreak
around the 25th of the month, with NLC being seen as far south as
Vancouver (lat. 49.2 deg N), and for a few late-season occurrences noted
from Baker Lake (lat. 64.3 deg N), with the latest sighting reported on
Aug 13/14.

A much later sighting took place on Nov 19/20 from Anchorage, Alaska,
when Dave Parkhurst unequivocally saw NLC in his southwestern twilight
sky from 0145-0215 UT (0445-0515 local). But with the Sun being only
3.6-6.7 degrees below the horizon during the observation range, the
bright twilight could have illuminated clouds at levels much lower than
the mesosphere.

On Jun 22/23, the author observed and photographed from Beaverhead
National Forest in southwestern Montana a display of NLC. The site, at
44.7 deg N latitude, is the farthest south from which an NLC display
has been both monitored visually and photographed in the ten-season
history of the NLC CAN AM network; previously, the record had been held
by Jay Brausch of Glen Ullin, North Dakota, who, at 46.8 deg N, has seen
and photographed several displays since 1993.

An unusual observation of NLC-like clouds took place on Feb 22/23 from
Reston, Virginia (lat. 39 deg N). William Burton observed and
photographed silvery loops low in the twilight sky. It was later
determined that the clouds were from rocket exhaust from a suborbital
rocket.

In 1997, aurorae and NLC were seen during 4 nights: Jun 8/9 and
Jul 9/10, 14/15, and 15/16.
 

Photographers in 1997 were Jay Brausch, William Burton, Gary Hargreaves,
Richard Huziak, Dave Parkhurst, Oscar Van Dongen, and Mark Zalcik.
 

Observers in 1997 were:

Individuals: Michael Boschat, Halifax, NS; Jay Brausch, Glen Ullin, ND;
William Burton, Reston, VA; Gary Hargreaves, Mission, BC; Robert Hughes,
Vegreville, AB; Richard Huziak, Saskatoon, SK; Lucian Kemble, Lumsden,
SK; Alister Ling, Bruce McCurdy, Murray Paulson, Don Thacker, Larry
Wood, Mark Zalcik, Edmonton, AB; Dave Parkhurst, Anchorage, AK; Gary
Thomas, Boulder, CO; Oscar Van Dongen, Vermilion, AB; unidentified Air
Canada pilot whose observation was relayed by the Churchill Flight
Service Station.

Canadian flight service and weather stations: Baker Lake, NT; Cold Lake,
AB; Churchill, MB; La Ronge, SK; Lynn Lake, MB; Prince Albert, SK;
Thompson, MB; Whitecourt, AB.

Thanks to Michael Boschat, Terry Ferguson, Robert Hughes, and the staff
observing at the La Ronge and Churchill flight service stations for
forwarding sightings from other sources. Special thanks to the over
one hundred observers all told who have participated in NLC CAN AM for
the past ten seasons. Their diligence in keeping watch for NLC has
resulted in an impressive dossier of data for evaluating NLC climatic
behavior in the late 20th century.

Table 1. Displays of noctilucent clouds over North America in 1997.
Times shown are UT ranges of compiled observations and may not truly
represent display durations. A short key to cloud types appears at
the bottom of the table.

MAY

Date | Time UT | Notes

11/12 0317-0350 Possible NLC in NW at Theodore, SK (R. Huziak).

29/30 0440-0510 Two faint bands seen in NW from Saskatoon.

31/Jun 1 0558-1135 Bright NLC overhead at Anchorage. Bands seen from N to NE at Thompson. NLC also reported at Churchill.

JUNE

Date | Time UT | Notes

8/9 0630-0915 Display seen in NW-NE in Edmonton and WNW-N at Whitecourt.

10/11 0525-0800 Evening NLC observed in Edmonton; display reached 70 deg. elevation and passed into the SW sky. Billows reported in NNE at Lynn Lake

12/13 0700-0900 NLC described as brilliant seen in NW-NE to 45 deg elevation at La Ronge.

13/14 0600 Faint NLC seen in NW, Whitecourt.

14/15 0515-0715 Well-observed display reported from three locations in Alberta as well as from Vancouver (where NLC were possibly seen again in the morning at 1005).

16/17 0540-0900 NLC in NE quadrant, Edmonton and Vermilion.

18/19 0720-0745 Veils and bands seen low in NE, Edmonton.

19/20 0500-1115 A night with extensive NLC, with displays seen in Val Marie, SK (M. Zalcik) and Saskatoon as well as in Vancouver, where NLC reached the zenith. Also, possible NLC at 0925 from Glen Ullin, ND.

22/23 1015-1100 NLC seen in NE from Beaverhead National Forest, MT, lat. 44 deg 44 m (M. Zalcik).

23/24 0532-1100 Expansive display in NW-NE-SE, Anchorage. Bright bands monitored in NW-NE, Saskatoon.

24/25 0355-0955 NLC seen over wide area, with reports from Glen Ullin, Edmonton, and Saskatoon. At Glen Ullin, the clouds were bright and were seen in both evening and morning twilight.

25/26 0550-0900 Displays seen from West Hawk Lake, Manitoba (M. Zalcik), Lynn Lake, La Ronge, and Saskatoon. Possible NLC as early as 0430 from West Hawk Lake.

27/28 0800 Billows reported at Lynn Lake.

28/29 0700-1005 Moderately bright display seen, Whitecourt, La Ronge, and Edmonton.

29/30 0448-1110 NLC from NE to due E at Anchorage. NLC seen nearly to zenith at Churchill, in evening twilight at La Ronge, Thompson, and Lynn Lakeand then in morning twilight from Vancouver.

30/Jul 1 0729-1115 NLC in NE-E at Anchorage and in NW at Whitecourt. Bands in NW-NE, Edmonton. Possible NLC in NW at 0800 from La Ronge.

JULY

Date | Time UT | Notes

4/5 0600-1000 Bright display seen from La Ronge. NLC also reported at Prince Albert, SK, Cold Lake, AB (in bright twilight), and Cypress Hills Provincial Park, SK (M. Paulson).

7/8 0700-0800 Bands seen in NW-NE at La Ronge.

9/10 0600-0700 Bands in NNW, La Ronge. Veils-bands,Edmonton

12/13 0600-0900 NLC centred along N horizon, La Ronge and Edmonton.

13/14 0900-0945 Morning twilight NLC seen from Edmonton.

14/15 0445-0900 Evening NLC seen at Saskatoon and Edmonton. Bright NLC in both evening and morning twilight, La Ronge. Possible morning NLC from 1110-1120 at Vancouver.

15/16 0355-1000 NLC widely observed by six observers across the prairies, as far S as Glen Ullin and N as Lynn Lake. Most observers saw NLC in the NW sky; from Glen Ullin the clouds were N at only 2-2.5 deg elevation.

24/25 0800-0900 Bands, billows, whirls in NW-NE, La Ronge.

25/26 0420-1142 Billows from W through NE near Talkeetna, Alaska (D. Parkhurst). Bands in evening twilight, Saskatoon. NLC from NW-E in morning twilight, Vancouver.

26/27 0830-1100 Massive display seen to zenith and reaching into the southern half of the sky near Talkeetna (D. Parkhurst).

27/28 0830-1130 NLC from W-NE near Talkeetna (D. Parkhurst).

30/31 0700-0800 Veils and bands seen, NW-NE, Baker Lake. NLC
also seen from aircraft over the Atlantic Ocean (G. Thomas).

AUGUST

Date | Time UT | Notes

2/3 0700 Veils just above NE horizon as seen from Baker Lake.

3/4 0600-0800 Bright bands from NW-ENE to 30 deg elevation, Baker Lake.

13/14 0800 Veils in NE to 35 deg elevation, Baker Lake.

NOVEMBER

Date | Time UT | Notes

19/20 0145-0215 NLC reported to 15 deg elevation in SW sky, Anchorage.