Introduction

SOLVE experimenters had the subjective impression that more wave events were encountered dueing SOLVE than on previous missions.  This web page reprots an objective analysis that confirms this impression.

Wave Score Defined

I shall arbitrarily define a "wave event" and "wave score" using the following definitions:

A "wave event" exists when the isentropes exhibit at least two well-defined peaks, or two well-defined valleys, separated by less than 1.0 ks, and when the peak-to-peak amplitude of any neighboring peak/valley/peak set (or valley/peak/valley set) exceeds 200 meters.

The "wave score" is the product of the peak-to-peak amplitude (defined above), measured in kilometers, and the square-root of the duration of the wave structure, measured in kiloseconds.

Results

The following table sumamrizes the Wave Scores for 11 Pre-SOLVE Arctic flights:
 

DATE [yyyy.mm.dd]	Wave Score	Event Details	Location
1992.02.12	0.0	Nothing	CA > N Can > CA
1992.03.10	0.7	0.5 km* (2.0)^0.5	CA > N Can > AK
1992.03.12	0.5	0.3km*(0.5ks)^1/2    +0.4km*(0.5ks)^1/2	AK > Greenland > Norway
1992.03.14	0.0		Norway > NP > Norway
1992.03.18	0.5	0.3km*(0.5ks)^1/2    +0.2km*(0.5ks)^1/2    +0.2km*(0.7ks)^1/2	Norway > Greenland > Bangor ME
1992.03.20	0.2	0.2km*(1.0ks)^1/2	Bangor ME > Canada > CA
1995.12.09	0.0		AK > AK
1996.01.28	0.0		AK > AK
1996.01.30	0.6	0.5km*(1.5ks)^1/2	AK > AK
1996.02.01	0.5	0.4km*(1.4ks)^1/2	AK > Iceland
1996.02.04	0.0		Iceland > AK

The following table sumamrizes the Wave Scores for xx SOLVE flights:
 

DATE [yyyy.mm.dd]	Wave Score	Event Details	Location
2000.01.25	2.95	0.50km*(1.2hr)^1/2    +0.53km*(1.6ks)^1/2    +1.14km*(2.2ks)^/2	Norway/Sweden & Norwegian Sea
2000.01.27	1.46	0.19km*(1ks)^1/2   +0.19km*(0.8ks)^1/2   +0.30km*(1.5ks)^1/2   +0.63km*(1.0ks)^1/2	Sweden > Finland > Russia > Norway > Norwegian Sea > Sweden
2000.01.29	0.73	0.52km*(2.0ks)^1/2	Sweden > CA
2000.02.27	0.00	Nothing	CA > Sweden
2000.03.03	0.81	0.23km*(1.1ks)^1/2    +0.205km*(1.2ks)^1/2    +0.28km*((0.8ks)^1/2	Sweden > N Greenland coast > Arctic Sea > Spitzbergen > Sweden
2000.03.05	0.23	0.24km*(0.9ks)^1/2	Sweden > N Russia > Kara Sea > Spitzbergen > Greenland Sea  >  Norwegian Sea > Sweden
2000.03.08	0.64	0.32km*(1.0ks)^1/2    +0.205km*(2.5ks)^1/2	Sweden > N Russia > Kara Sea > Spitzbergen > Sweden
2000.03.09	1.94	0.24km*(2.0ks)^1/2    +0.46km*(1.8ks)^1/2    +0.71km*(1.9ks)^1/2	Sweden Greenland Sea > Iceland > England > Sweden
2000.03.11	0.42	0.34km*(1.5)^1/2	Sweden > Berents Sea >    Sweden
2000.03.13	0.91	0.69 km*(0.7ks)^1/2   +0.60 km *(0.3ks)^1/2	Sweden > Kara Sea > Arctic Sea > Greenland Sea > Sweden
2000.03.15	0.00	Nothing	Sweden > Can > CA

The average Wave Score for the SOLVE flights is 0.92 +/- 0.27.  The average Wave Score for the Pre-SOLVE flights is 0.27 +/- 0.09 [km*ks^1/2].  The Wave Score difference between the two flight groups is WS(SOLVE) - WS(Pre-SOLVE) = 0.64 +/- 0.28 [km*ks^1/2].  This is a 2.28-sigma difference, and has modest statistical significance.

Wave Encounter Incidence Statistics

During 11 flights, comprising 90.8 flight hours, 21 wave events were encountered.  This corresponds to one wave encounter per 4.3 flight hours.  The accumlated duration of these 20 encounters represents 8.3% of flying time.

Conclusions

The fact that the SOLVE mission encountered more wave events than the pre-SOLVE missions can probably be attributed to mission planning differences between the missions.  Many of the SOLVE flight tracks are over mountainous regions, and mission planners stated their interest in flying where mountain waves were predicted.  Therefore, I am reluctant to attribute the greater wave encoutner statitics for SOLVE to differences in meteorology.

The wave event of 2000.01.25, at 60,200 utseconds is impressive!  I believe it is the largest amplitude wave documented by any MTP instrument. The previous record-holder was for the ER-2 during the 1987.09.22 flight over Antarctica.  That wave showed a significant growth of wave amplitude with altitude, and if an overlap altitude, such as 18 km, is considered the SOLVE event is much larger.

This site opened:  March 18, 2000.  Last Update: April 1, 2000