THE UNIVERSITY OF MICHIGAN COLLEGE OF ENGINEERING Department of Civil Engineering Meteorological Laboratories ATMOSPHERIC DIFFUSION STUDY AT THE ENRICO FERMI JNCLEAR REACTOR SITE Second Progress Report A QUALITATIVE ANALYSIS OF FURTHER DIFFUSION EXPERIMENTS E. Wendell Hewson Professor of Meteorology Gerald Co Gill Associate Professor of Meteorology Eugene W. Bierly Assistant Research Meteorologist UMRI Project 2728 under contract with: POWER REACTOR DEVELOPMENT COMPANY DETROIT, MICHIGAN administered by: THE UNIVERSITY OF MICHIGAN RESEARCH INSTITUTE ANN ARBOR July 1960

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PREFACE This second progress report presents a qualitative estimation of atmospheric diffusion at the Enrico Fermi plant site during the winter and spring seasons of 1960. The individual experiments are treated in a manner similar to those in the first report. The authors wish to make the following acknowledgments: to Mr. Dwight Meeks for use of his tape recorder; to Lt. Michael J. Menadier, Weather Services Officer at the Grosse Ile Naval Air Station, for allowing the hourly weather observations to be copied and for doing the synoptic map analysis; to Colonel W. R. Schaal and Captain John Doty of the 127th Tactical Reconnaissance Wing of the Michigan Air National Guard based at Detroit Metropolitan-Wayne County Airport for photographing the smoke plume and developing the film; to Mrs. Anne C. Rivette, for typing the manuscript; and to supporting personnel of the Meteorological Laboratories for abstracting the data and putting it into usable form. iii

TABLE OF CONTENTS Page LIST OF TABLES vii LIST OF FIGURES ix ABSTRACT xi I. INTRODUCTION 1 II. EXPERIMENTAL RUNS 5 1. Experiment of 4 February 1960 3 2. Experiment of 3 April 1960 15 3. Experiment of 8 May 1960 28 4. Experiment of 25 June 1960 36 III. SUMMARY OF EXPERIMENTS 47 V

LIST OF TABLES No. Page I Hourly Average Values of Wind Direction, Wind Speed, and Temperature-Lapse-Rate Data from the Meteorological Tower at the Enrico Fermi Site on 4 February 1960 10 II Hourly Average Values of Wind Direction, Wind Speed, and Temperature-Lapse-Rate Data from the Meteorological Tower at the Enrico Fermi Site on 3 April 1960 25 III Hourly Average Values of Wind Direction, Wind Speed, and Temperature-Lapse-Rate Data from the Meteorological Tower at the Enrico Fermi Site on 8 May 1960 33 IV Hourly Average Values of Wind Direction, Wind Speed, and Temperature-Lapse-Rate Data from the Meteorological Tower at the Enrico Fermi Site on 25 June 1960 40 V Summary of Experiments at the Enrico Fermi Nuclear Power Plant, Lagoona Beach, Michigan 48 vii

LIST OF FIGURES No. Page 1 0700 EST surface weather map of 4 February 1960. 5 2 Surface weather observations taken at U. S. Naval Air Station, Grosse Ile, Michigan, on 4 February 1960. 7 3 Map of the local area in the vicinity of the Enrico Fermi plant site. 8 4 Idealized time variation of vertical temperature distribution at Grosse Ile, Michigan, during the night of 3 February and early morning of 4 February 1960. 9 5 Vertical temperature distribution to 4 ft over the water and at the plant site on the morning of 4 February 1960. 9 6 Plots of the vertical temperature distribution as recorded by the aerometeorograph during the afternoon of 4 February 1960. 12 7 View looking northward as smoke leaves the 40-ft level of the meteorological tower on 4 February 1960. 13 8 View looking westward as smoke plume intersects with the ground west of the parking lot. 13 9 View looking westward from top of meteorological tower as smoke leaves the tower and flows westward. 14 10 Sketch of streamlines of wind flow from the lake deflected by rock embankment. 14 11 Aerial view looking south as smoke leaves tower and flows westward over the land. 16 12 Aerial view looking south of smoke diffusing inland. 17 13 Aerial view looking south, showing the greater diffusion of the smoke after an overland trajectory. 18 14 Raw counts of FP material from 4 February 1960 plotted according to azimuth and height above the lake surface. 19 15 0700 EST surface weather map of 3 April 1960. 21 ix

LIST OF FIGURES (Concluded) No. Page 16 Surface weather observations taken at the U. So Naval Air Station, Grosse Ile, Michigan, on 3 April 1960. 23 17 Plots of the vertical temperature distribution as recorded by the aerometeorograph on 3 April 1960. 24 18 Raw counts of FP material from 3 April 1960 plotted according to azimuth and height above the lake surface. 27 19 0700 EST surface weather map of 8 May 1960. 29 20 Surface weather observations taken at the Uo S. Naval Air Station, Grosse Ile, Michigan, on. 8 May 1960. 31 21 Plots of the vertical temperature distribution as recorded by the aerometeorograph on 8 May 1960. 32 22 Raw counts of FP material from 8 May 1960 plotted according to azimuth and height above the lake surface. 35 23 0700 EST surface weather map of 25 June 1960. 37 24 Surface weather observations taken at the U. S. Naval Air Station, Grosse Ile, Michigan, on 25 June 1960. 59 25 Plots of the vertical temperature distribution as recorded by the aerometeorograph on 25 June 1960. 42 26 Raw counts of FP material from 25 June 1960 at 2 and 4 km plotted according to azimuth and height above the lake surface. 43 27 Raw counts of FP materials from 25 June 1960 at 8 and 16 km plotted according to azimuth and height above the lake surface. 44 x

ABSTRACT Experimental runs were made on February 4, April 3, May 8, and June 25, 1960. A general discussion of the synoptic situation for the day of each. experiment is presented along with the Monroe area weather details, special characteristics at Lagoona Beach, plume characteristics, and results of the plane sampling. A qualitative estimation is then made of the atmospheric diffusion for each experiment. A summary of all the experiments concludes the report. xi

Io INTRODUCTION Since this project was initiated to study atmospheric diffusion in transitional states at the reactor site near Lake Erie, it might be well to define such diffusion again. Diffusion in transitional states is the condition that exists when the field of atmospheric turbulence exhibits marked variation in time or space or both. At a shoreline there are marked horizontal variations in turbulence. Air flowing from land over a cool water surface, as in spring, becomes increasingly stable and experiences reduced mechanical turbulence over the relatively smooth water surface. In the autumn the water is relatively warm and the air leaving the land may develop instability and thermal turbulence over the water, leading to enhanced diffusion. An effort was made to obtain data over Lake Erie during the spring when the water was cold. Unfortunately, no run was successful until 25 June 1960, because our trained crew of students was available only during school vacations or weekends. The probability of westerly winds of sufficient magnitude to overcome the lake-breeze effect on weekends was quite small. Once school was over, it was possible to devote all forces to make a run on a suitable day. Ironically, June 25 was a Saturday anyway. Thus, four experiments have been carried out and are reported on qualitatively in this report, as were the first four experiments in progress report 2728-1-Po A summary of all eight experiments concludes the report with remarks about their value in computing diffusion parameters. Quantitative estimates for all eight experimental runs will be contained in a separate technical report, 2728-5-T. 1

II. EXPERIMENTAL RUNS 1. EXPERIMENTAL RUN OF 4 FEBRUARY 1960 a. Synoptic Situation.-The surface weather map at 0700 EST on 1 February shows a large, cool high-pressure area centered near Killaloe, Ontario, with one ridge extending southward beyond Cape Hatteras, North Carolina and another ridge extending westward to western Lake Superior (see Fig. 1). A widespread, stagnant, low-pressure system was centered near the eastern Texas-Oklahoma border. Approximately 450 miles east of the low center an occluded front lay with the warm front skirting the northeastern Gulf of Mexico shore and then passing through the northern part of the Florida peninsula. The cold front ran southward through Pensicola, Florida, and then into the Gulf of Mexico. The western U. S. was under the influence of a NE-SW-oriented highpressure area centered in the southeastern corner of Idaho. An insignificant low center was located on the Saskatchewan-Montana border with a weak stationary front running eastward through southern Hudson Bay. As a result of the circulation from both the Ontario high and the Texas low, the Great Lakes region was in an area of easterly winds. Due to surface friction effects, the winds actually observed were from the northeast and eastnortheast. The air mass represented by the high-pressure area over Killaloe was initially of a continental polar type; however, it was beginning to modify so that the temperature near the surface during the daylight hours was beginning to run well above the freezing point. It is important to note this fact, for there was quite a difference in diffusion when this air was passing over water and when if passed over land. b. Monroe Area Weather.-Figure 2 shows the hourly surface observation as recorded at Grosse Ile Naval Air Station. Refer to Fig. 3 for the location of Grosse Ile relative to the plant site. The winds at Grosse Ile were from the east-northeast throughout the day. Figure 3 shows that an ENE wind is a land trajectory for Grosse Ile, but that it is a water trajectory at the reactor site. Visibility at the air station was below three miles from 0740 EST until 0956. Such visibilities in fog and smoke are indicative of inversion conditions. This conclusion seems probable because it appeared to have been a clear night. See the 0557 EST observation of clear skies and 7 miles visibility. 3

Under such conditions, the earth's surface cools by radiative transfer, so it assumes the lowest temperature. Note that at 0759 EST the temperature was 23~F (-5.0~C). This reading was made at a height of 4 feet above the surface, so the temperature near the surface would be even colder. Any air above the earth's surface, even if it were from a cool air mass, would be relatively warmer than the surface under such a condition, so an inversion could form. Figure 4 illustrates this process during the evening and early morning hours. Although no temperature-lapse-rate measurements were made at Grosse Ile, it is felt that such was the condition during the early morning of 4 February. From the observations, it appears that this nocturnal inversion dissipated between 1000 and 1100 EST. The ground fog and smoke lifted and the temperature rose 8F~ (4.2C~) in one hour, indicating that mixing from aloft had taken place. As the day progressed at Grosse Ile, the temperature continued to rise until 1357 EST when it reached a maximum of 420F (5.6~C). In all probability, the lapse rate became strong after 1100 EST due to the solar heating and continued so until after sunset. c. Special Characteristics at Lagoona Beach —The data from the meteorological tower at the plant site are shown in Table I. It can be seen that the wind data at the plant agree with the Grosse Ile observations as to direction. The speed naturally is higher at the plant site due to the greater height of the aerovane there than at the air station. The lapse-rate data at the plant site initially seem to be in error since they indicate a strong lapse condition', but a deeper analysis shows that they are not. The first fact to be kept clear is that the ENE winds at the plant site are an over-water trajectory for a distance of well over ten miles. At Grosse Ile such a trajectory is over land. The lake temperature on 4 February was about 34~F (1.1~C) with a good deal of open water between the ice flows. Assuming that the temperature 4 ft above the water was the same as Grosse Ile's at 0759 EST, that is, 23~F (-5.0~C), then the temperature profile would be as shown in Fig. 5, at least up to 4 ft. In other words, it would be a super adiabatic lapse-rate condition over the water. In reality, it probably was not as strong a lapse rate as indicated because some heat from the water would be transferred upward, thus warming the air above the water's surface. However, we may postulate that the vertical temperature profile at the plant site was similar to that shown in Fig. 5. The observed lapse rates at the tower are indeed correct and shall be accepted as being accurate. It is important to note that by the time the Grosse Ile area was having a lapse-rate condition, about 1100 EST, the tower site's temperature lapse rate began to change from strong to weak and finally to an inversion. This situation may be analyzed as follows. 4

STATION_ US. NAVAL A/R STAT!ON GROSSE ILE M/H_. DATE - _,2 - /, VISIB- WEATMER SEA DEW WIND ALTI- O-S TwYP TI E S$KYond CEILING ILITY aCnd O LEVEL MPT DIREC-jIspEE HARA ETER YPELST (HundrdTIE Fet) (M Y OBSTRUCTIOS ESS (OF) F T I r TER & SET. REMARKS AND SUPPLEMENTAL CODED DATA VER (C9LST)r (MIundwr s o F~et) (MRile) rTO VISION (mbS.) () T IN knotS) FS (in.) Initial _L*. I Z. 4 1 6? 9 e I I// /P _3_ /4af I5 /5.._._. 7_. 7. $7I l_ — 0 I 1 /' 37'. E / i;, _ | -________~ / _ - _ t t l | I t. 07: E /0 c Z 1 2..L 2.t 80 B 3 $JI/ I I, i 1______1_1_!_I 1. / ".. I/< 5'3 e/ __ /o -. _ g/.Fke | <-. I I. 1 |.1! z o~.~ /~o-d) /~ F,~' ~7~~ 1 _ ~ t"' d I ocI. 1 __. ^5_0___ 0O _ |_ 3 |Z zZT 7 9 1 l { i S / __ ___ _ _ - 1 40 60 -? /,/ K~ / — -4 U^ 17J 1371 K 11- I' R. / -~' I 3,: 7? j- j 1' 1 1,...... "^ 2 C-4~, 7 / __-./__ 7__' -n —- 1/ 1./- __d_ __ j_,____:.//C7 //3 39 i.-.,K _.... I I': /,: /-~ 7LZ 7y __ _-, ] ___ t'/ /,,__,e l' _K, /,7SS /~ - & 233 3~, s L ~,z -,,...... I \ ^., /s /,o < f3 1i 7 I i y z 1e3.2, 41R/ /az7 __ [~._I // fft ~/7 3..,z.....// e3/' /677_I I *See /-JSTB Circular N for definition of symbols and abbreviations. Fig. 2. Surface weather observations taken at U. S. Naval Air Station, Grosse I2e, Michigan, on 4 February 1960.

DETROIT A....~ ~ ~~A ^1ANN ARBOR:?^ ^^==s^=^=^;^ / ^.J:;a^^A/lIN DSOR^ ^- J ^V.ROSSE ILE NAVAL AIR STATION ^ SCALE T X^'^ ^ 1/' co, L I I ITE~~~~~~~~~~~~~~~~~~~~~~~~,.:~~.=,......: 0 10 20. - ^ Miles r \ > ^ j /^^ / /CLEVELANAI Scale Fig- 3- Map of^ the local area in the vicinity of the Enrico Fermi plant site.

- 1800 EST \ —=2100 EST I - — =OOOOEST Z height - -=0300 EST --— =06 00 EST / / 0 T —temperature Fig. 4. Idealized time variation of vertical temperature distribution at Grosse Ile, Michigan, during the night of 3 February and early morning of 4 February 1960. 4' — --—. — --------— + — t I l \ Z \ height 0 20 25 30 35 T - tempe rature Fig. 5. Vertical temperature distribution to 4 ft over the water and at the plant site on the morning of 4 February 1960. 9

TABLE I HOURLY AVERAGE VALUES OF WIND DIRECTION, WIND SPEED, AND TEMPERATURE-LAPSE-RATE DATA FROM THE METEOROLOGICAL TOWER AT THE ENRICO FERMI SITE ON 4 FEBRUARY 1960 Hour Ending Wind Direction Wind Speed (mph) Lapse Rate 0100 ENE 15 S 0200 ENE 14 S 0300 ENE 15 S 0400 ENE 19 S 0500 NE 14 S 0600 NE 14 0700 NE 17 S 0800 NE 16 S 0900 NE 15 S 1000 NE 13 S 1100 ENE 16 W 1200 ENE 19 W 1300 E 17 W 1400 E 16 W 1500 E 12 I 1600 ENE 10 I 1700 ENE 15 I 1800 ENE 12 I 1900 ENE 12 I 2000 E 9 I 2100 ENE 8 I 2200 ENE I 2300 E 7 2400 EE 6 I 10

As the day progressed, the air temperature rose, reaching a maximum temperature at Grosse Ile of 42~F (5.6~C) at 1357 EST. This warm air from the Canadian shore passing over the then relatively colder water would cause an inversion to form. (See Fig. 6 which shows the soundings taken by the airplane during the afternoon.) The sounding taken by the plane at 1435 over the water indicates that an inversion did exist at that time. The land sounding taken at the same time indicates a lapse condition to about 1500 ft above ground and then an inversion above that. By the time the later soundings were taken near 1630 EST, the land temperature had begun to drop. This is seen in the sounding. The over-water sounding at 1616 showed that a great deal of warming had taken place in the lower several hundred feet yet the lake surface was still near 32oF (0.0~C) indicating that the temperature difference between 4 ft and 100 ft at the tower would still read as an inversion. This is confirmed in Table I where hourly average values of wind direction, speed, and temperature lapse rate as measured at the meteorological tower on the plant site are shown. This section can be summed up by saying that great differences are caused by the proximity to the lake especially if the prevailing wind flow is from off the water. d. Plume Characteristics.-Aerial photographs and ground photographs were taken of the smoke plume that was released from the tower. Because of mechanical difficulty, the airplane was not able to sample until midafternoon, whereas the jet reconnaissance plane was available about noontime. Since it was felt that the aerial photography would add materially to this diffusion experiment, it was decided to release a continuous oil-fog smoke plume from the 56-ft level of the tower during midday. The plume left the tower in more or less of a straight line as seen in Figs. 7 and 8. By the time this smoke had reached the western end of the parking lot at the plant site, it was down on the ground. (See Fig. 9.) Since the lapse rate at the tower between 4 ft and 100 ft was weak, it seems strange that the smoke should intersect the ground within such a short distance. Such a condition would be expected with a strong lapse rate when there is a great deal of mixing. The following explanation is offered. The easterly wind from off the lake passing over the shoreline was deflected upward due to a rock embankment which was placed between the lake and the tower during construction of the plant. (See Fig. 6 of 2728-1-. ) A further proof of this deflection is that the 56-ft bivane recorded a continuous updraft throughout this period of the day. It is postulated, then, that the wind flow deflected by the embankment caught the plume as it left the tower and lifted it. This cold air from off the water would be cooler than the environment surrounding it and hence would tend to sink at some distance from the lake shore. This sinking brought the lower edge of the plume to the ground at a distance of about 600 ft from the tower. This explanation is sketched in Fig. 10. 11

4 FEB. 1960 STime relative to Sounding relative to plant site Symbol Est. Surface Azimuth Radius (KM) Symbol Est. Surface Azimuth Radius (KM) D —-- 1425 Land 2900 6.0 K -—, 1645 Land 0 —01434 Water 120~ 2.1K 0 —01616 Water 2000 930 2000 930 1800 1800 \940 -940 \ /.\ \. 1600 \ / 1600 Z 60 - T /I - 950 4 0 0 D! \ 0 40 0 950 o 1400- 1400C Ir \ 1 (3 I iw >. 0 1200 m 960 n 1200- co theaerometeorogrh 9600 n <t - 960 L 1000- 000- =) O3 O3Y10 0 [, \ -970 w z -970 L 00 I- 970" 800. 8 800w \ \ 600- 980 600- 980 \1 \ ^I~f-Dry adiabat 400 990 400 990 990 \ - 990 200- 200 b I| I| j | I \ |1I — 000~ I I I I I I I F I 1-1000 0 I 2 3 4 5 6 7 8 9 10 0 I 2 3 4 5 6 7 8 9 10 TEMPERATURE IN ~C TEMPERATURE IN OC Fig. 6. Plots of the vertical temperature distribution as recorded by the aerometeorograph during the afternoon of 4 February 1960. 12

Fig. 7. View looking northward as smoke leaves the 40-ft level of the meteorological tower on 4 February 1960. Fig. 8. View looking westward as smoke plume intersects with the ground west of the parking lot. 13

I "'I Fig. 9. View looking westward from top of meteorologoical tower as smoke leaves the tower and flows west-ward.. // Fig. 10 Sketch of st:reamlines of wind f1ow from the lake deflected by rock emb ankme nt. 14

The smoke plume traveled for at least five km along or near the ground with little vertical diffusion. Figures 11, 12, and 13 give an idea of the length of the smoke plume. Note that the smoke can still be seen in the right of Fig. 13, indicating that perhaps it could be traced even further downstream. All the pictures show a relatively flat bottom to the smoke, which would indicate that it was on the surface of the ground. The top edges get more and more diffuse, showing that some vertical diffusion was taking place. Note the evidence of wind shear near the 2-ki marker in Fig. 11. The further inland the plume progressed, the better were its chances for diffusion, since only in the vicinity of the lake would the temperature lapse rate have been weak. Over the land away from the lake breeze inversion effect, there would likely be a strong lapse rate due to solar heating. This effect is shown in Fig. 13 where the plume is relatively narrow at the 3-km marker and considerably wider at the 5-km marker. The FP plume was released when the lapse rate at the plant site was recorded as an inversion condition. The smoke puffs released at the same time indicated that the plume width was about 12~. This figure is probably too high since the observations were taken within 100 ft of the point of release. It is believed that the FP plume behaved quite similarly to the smoke plume. e. Results of Plane Sampling.-Figure 14 shows the results of the FP counts as collected on the drum sampler. There are several important facts to be pointed out. First, the plume is well defined at all radii and all levels. On the 2-km arc the plume is quite narrow but by the time 4 km were reached, the plume had begun to spread out more evenly, indicating that surface roughness and change of lapse rate had begun to aid in a more rapid diffusion of the material. Secondly, notice that no samples were collected above 300 ft, although by 4 km it can be seen that there was some diffusion upward. It is quite unfortunate that sampling was not carried out on the 8km arc. f. Comments on the Diffusion Patterns.-This experiment is certainly of diffusion in transitional states. Obviously diffusion was not good in the immediate vicinity of the plant site, but this condition began to change as the plume was carried inland. Here is a case of a strong off-lake wind changing the entire diffusion characteristics of the plant area. The effect of the lake is dominant. 2. EXPERIMENT OF 3 APRIL 1960 a. Synoptic Situation.-At 0700 EST the surface weather map, Fig. 15, shows a long occluded front running from near North Bay, Ontario, southward through central Lake Erie and then south-southwestward to Montgomery, Alabama. 15

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Fig. 12. Aerial view looking south of smoke diffusing inland. 17

ii-i iii~iiiii~i~i~........I - 4 m::: —-:-:.:i l::::::Fig 1 3 eilve okn ot, hwn h rae ifso of~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ th smok after: an ovrln tri ajtory.i-~-iiiiiiiiii~iii

4 KM ARC (1523-1558) 4th Feb.'60 800 0 0 0 6400 0 00 0 0 0 0 0 0 o 400 - 0 0 72 - — 10 -, -I,-, 00 z 0 46 I L 36, 0O O o < l I l l l l l l l l l l l I0~~~I0 200 I I W > 600 __ 0 0 153 I 1460 0 0 0 D I I I a I I I W 2 KM ARC (1448-1513) uJ w Direction of flight same for aol levels 400 0 0 l0 -0 0 0o I \, o 0 04 0 0 200-1 ~ ~0 0 10 2311 0 0. 2 16 1295 6 3 3 2 oL I I I' I I I 22 230 240 250 260 270 280 290 2 310 320 330 AZIMUTH Fig. 14. Raw counts of FP material from 4 February 1960 plotted according to azimuth and height above the lake surface.

A low was centered about 50 miles southeast of Meridian, Mississippi, with the warm front extending northeastward to meet the occlusion near Montgomery. The cold front from the Mississippi low ran southward into the Gulf of Mexico. Another low-pressure area was centered some 300 miles west of southern Hudson Bay. An occluded frontal system ran from Le Pas, Manitoba, southward through central North Dakota and thence southwestward through central Wyoming. A large high-pressure center was located south of Halifax, Nova Scotia, causing a strong southerly gradient ahead of the eastern U. S, occluded front. Thus the synoptic pattern caused the area at and adjacent to the plant site to have a westerly wind that became less and less strong as the day progressed. In such a situation, the lake-breeze effect could become a significant factor. b. Monroe Area Weather.-The Monroe area was in an area of weak pressure gradient which allowed the wind direction to be light and variable. Figure 16, which is a copy of the hourly surface weather observations from the U. S. Naval Air Station at Grosse Ile, Michigan, shows that the wind was light, never reaching more than 4 knots all day, and also quite variable in direction, although there seems to have been a definite southerly dominance throughout the daylight hours. This S and SSE wind is the lake breeze as evidenced by the decrease in rapidity of temperature rise after 0900 and the increase in the temperature of the dew point after 0800. Both observations lend evidence to the notion that a lake breeze had developed at Grosse lie even though the gradient wind was westerly. Visibility remained excellent throughout the day even during several late afternoon rainshowers. These showers were caused by a trough which passed in the afternoon. As the day progressed, a high deck of cirrus clouds began to appear, eventually becoming an overcast. A middle layer also began to appear at 1055, and by 1657 was a solid overcast. Low clouds appeared first at 1758 and thickened as long as observations were taken. Since the lake was still quite cold during this period, it is probably safe to assume that an inversion was formed over the area surrounding the lake shore soon after the lake breeze set in. Confirmation of this assumption is given in Table II, which indicates that an inversion was observed at the plant site continuously on the meteorological tower. Figure 17 indicates that the aerometeorograph measured an inversion over the lake and the surrounding swampy area north of the plant site proper. This, too, supports the assumption of an inversion formation following the lake breezeo c. Special Characteristics at Lagoona Beacho-Table II shows the hourly average wind speed, wind direction, and lapse rate as measured on the 100-ft meteorological tower at the plant site. The first conclusion is that the wind 20

STATION _U.S. NvVAL _A/R STATIO/N GROSSE ILE MCH. DE 3_ AA/J_ 7 VISIB- WEATHER SEA DEW WIND LAM- OBSERTYPE TIME SKY and CEILING ILITY and LEVEL PT DIRECISpEEdCARA TER VRS )TYPE T HndrE S of FeYELN6 ) OBSTRUCTIONS PRESS. (F) V QrF) TI N TE SET. REMARKS AND SUPPLEMENTAL CODED DATA (LST) (Hudndre of Fet) (Mies) TO VISION (mnbs.) ( TION )SHIFrTS (nin) j(Ltrro4 ~\r'IS H IFTIS (ins.) / z 3. G 6 7.. 9 JS O Q I // /3 14A 4B /S 1 ^ i /2 o 5- 44 | ______ / 8 3~- i / i | 130J. 1 4A /42.1 __~g /~. /~ 1/7 I1 I' I 1oQ/ //4 /1"2 -'I I!,- &- /'' ", /7 1, "a2 1 c"''"" /''''________________________ 41 7 Z iR 0 /18 /67 Y 9 I I 3 000 /?R~~ I/^OX.CZ~~~~ /Gff^/fS<~~~~~..J___) _^ I,,;4,Y ISO,, 1,,,,,,~~~_,_!_Il___I,,'2A / /? r /.S // 0 0/? | f I. I. \.. W 5/ 1 E ^/{S I/~III3_________ _ 1___________________________ /1 / f-o 0 Z s)/ /0 ___y/e _ I3 /077 7 I I__ - g __ __ /^ a _____ __ /^ ____I__ /^/.<7S 1 4, 1__.________1I —2a R P7o X R- IX4.E, E~z) 1/S I /S... Grss 1-,. I MicigaIo 3 4,' i, 1960......'ZR /6 E.2__I/^>I/ -? /7' I\ 4'8a B ~..._________________.. F-ig. 16. Surface weather observations taken at the U'. S. Naval Air Station Grosse le Michigan I, on 3 April 10.___________________ X /9? E/7 > 3 f I I/_____6 ^r ^3 I ^fg/_____ - _________lI 1 __<r _ obS_ _ I_____ I I J c I - Eig. 16. Surface weather observations taken at the U. S. Naval Air Station, Grosse Ile, Michigan, on 5 April 1960.

3 APRIL 1960 Time Sounding relative to plant site Sounding relative to plant site Symbol Est. Surface Azimuth Radius (KM) Symbol 0 —- 1148 Land 270~ 14KM — O 1637 Lake 105~ 2.0KM O —-O 1205 Swamp 00 IKM 0 —-—, 1645 Swamp 00 IKM -—.-L 1220 Lake 1350 5.4KM 1600 1 1600 100 W\ \50 -940 \ -940 14000 1400 0 1200950 1200 950 w 950 - 950 > CD \ [| L \1. \I I > 10 u8- 9 960 1 \ t0 100 < - - \ Fg 17 800 - z 800 - 800 0o w - > (V) LL Cn) Uj 600 1 970 C) 600 970 LI w \ \I\ 0. FQ400 w 400 w w 980 IA \\-980 \ \:: 200- 9 200 Dry ad/abu - 0c___ I \ __ I 990 I I I I I h990 8 9 10 II 12 13 14 15 16 17 18 8 9 10 II 12 13 14 15 16 17 18 TEMPERATUREOC TEMPERATUREOC Fig. 17. Plots of the vertical temperature distribution as recorded by the aerometeorograph on 5 April 1960.

TABLE II HOURLY AVERAGE VALUES OF WIND DIRECTION, WIND SPEED, AND TEMPERATURE-LAPSE-RATE DATA FROM THE METEOROLOGICAL TOWER AT THE ENRICO FERMI SITE ON 3 APRIL 1960 Hour Ending Wind Direction Wind Speed (mph) Lapse Rate 0100 SSW 14 I 0200 W 11 I 0300 NW 13 I 0400 NW 11 I 0500 NW 8 I 0600 NW 9 I 0700 W 7 I 0800 SW 7 I 0900 SSW 6 I 1000 S 7 I 1100 SSE 7 I 1200 SSE 9 I 1300 SSE 9 I 1400 SE 8 I 1500 SSE 7 I 1600 SSW 5 I 1700 msg msg I 1800 msg msg I 1900 msg msg I 2000 msg msg I 2100 msg msg I 2200 msg msg I 2300 msg msg I 2400 msg msg I 25

regime at the site was similar to that at Grosse Ile. The lake breeze began to be felt between 1000 and 1100 EST as evidenced by the S to SSE wind. The wind speeds are higher at the site but this can be accounted for by the different exposures of the wind instrument at Grosse Ile and the site. It seems, then, that the normal nocturnal inversion was replaced by a lake-breeze-induced inversion, causing inversion conditions throughout the day. It should be noted from Fig. 17 that over land, at any point far enough away from the influence of the lake breeze, a weak lapse-rate condition existed. The data of Fig. 17 are interesting from another standpoint. A sounding was taken over the swamp at 1205 EST and again at 1645 EST. At 1205 EST there was an inversion from the surface to 700 ft. At 1645 the inversion still existed but was weaker and extended from the surface to 900 ft. It seems safe to assume that the horizontal extent of the lake-breeze-induced inversion probably had increased inland during this period, too. Thus the area imrrediately adjacent to the lake and the lake itself was in an area of poor diffusion, while at inland stations moderate diffusion is likely to have occurred. d. Plume Characteristics.-Aerial photographs were not taken during this experiment due to the short notice of performing the experiment. The smoke generator was not working properly, so no comments can be made concerning the visual characteristics of the plume. e. Results of Plane Sampling, -The plots of the FP counts are shown in Fig. 18. Unfortunately, the aerosol generator was not operating at its usual capacity; hence the emission rate was reduced to almost 1/10 of its prior output. Even so, the counts do indicate that the plume was low and quite small in width. In fact, at 2 km the plume was only 20~ or less in width and there were no particles collected above 200 ft. At 4 km, only scattered particles were collected above 300 ft, but the plume had spread out horizontally to as much as 30~ in width. f. Comments on the Diffusion Patterns —April 3 was actually quite a common type of day at the plant site —a weak pressure gradient, warming over the land during the day, a cold lake, and hence a lake breeze which induces an inversion in the areas immediately adjacent to the lake. Diffusion in this region would not be expected to be good. As one gets further from the lake, the vertical temperature structure changes from an inversion to a lapse condition, so diffusion should get progressively better. The occurrence of rain showers superimposed upon such conditions may be considered as either favorable or unfavorable depending on where the washout would occur. In an uninhabited area, of which there are many around the lake, it could be considered good. 26

4 KM ARC (1311-1354) 3 rd April,'60 800 10 I10 0 0 0 0 0 0 0 2 0 400 I-o \ 0 I 20 0 w 200 -0 1 0 30110 03 m0-0- III- -.... I I I I I I I I 400. I Ic I I I I I I I U 2 KM ARC (1233-1256) 2 600 <- z 2600 I 0 0 0 0 1 0 I 0 1 1 0 1 H I I -J w 400t 1 0 0 0 0 0 0 0 0 0 I O I O I O I O I O 0 0 0 0 0 0 0 0 0 I I 0 10 0130 31 0 0 0 0 400 I I I I I I I I I I I 240 250 260 270 280 290 300 310 320 330 340 350 360 AZIMUTH Fig. 18. Raw counts of FP material from 3 April 1960 plotted according to azimuth and height above the lake surface. 24~~~~0 5 6 7 8 9 0 1 2 3 4 5 0 0 i ~A IM T

3. EXPERIMENT OF 8 MAY 1960 a. Synoptic Situation.-The surface map at 0700 EST showed several lowpressure centers in the eastern United States (see Fig. 19). The northernmost center was located just east of Erie, Pennsylvania, while the second was over Sumpter, South Carolina. A cold front ran from the northern low southward to the southern one, becoming a warm front just before entering the Carolina low. Another cold front ran southward from Sumpter, South Carolina, through the southeastern tip of Florida. A third low-pressure area was centered over Sheridan, Wyoming, with an associated cold front going southward through central Colorado and then through the northwest corner of New Mexico. Two high-pressure areas dominated the central U. S. The southern one was located over Houston, Texas, with a ridge pushing as far northward as central Kansas. Another ridge of high-pressure from a center located near Hudson Bay pushed down into northern Nebraska. The net effect at the plant site was that the winds were westerly, but the gradient was quite weak, thus causing the winds to be variable in direction. b. Monroe Area Weather. —Figure 20, the hourly surface observations from Grosse lie, indicates that the winds were generally from the northwest at speeds of 3-4 knots until 1058 EST. From 1058 to 1556 EST the winds were very light and variable in direction, but usually with an easterly component. Visibility was good all day. Throughout most of the day there was a high overcast of cirrostratus clouds. From 0900 until 1500 EST, there was also an overcast of altocumulus type clouds. Beneath the middle layer were some low stratocumulus which came and then disappeared and then returned again before the afternoon was over. The lake temperature during this period of the year usually runs about 50~F (10.0~C). It is of interest to note that the maximum temperature for the day was only 50OF (10.0~C). Thus it seems plausible that there was no inversion around the lake shore throughout the day. This is fairly well substantiated by Table III and Fig. 21, which show the observed lapse rates at the plant site and in the sampling area. c. Special Characteristics at Lagoona Beach.-Table III presents the hourly average values of wind direction, wind speed, and temperature lapse rate as observed on the meteorological tower at the plant site. It is unforunate that the wind direction is missing during the early morning hours, but it can be assumed that it was a northwesterly wind since the wind at Grosse Ile was from that direction. Again the wind speed is higher but this has been explained in earlier experiments. Between 0900 and 1000 EST, the wind began 28

STATION -I.S. NA4L AIR STATI/Ot GROSSEL MI.CH DATE MA// I /_< VISIS- W T R SEA WTHER D LIM-OSE-.F TYPE TIAE OBSTRUCTIONS PRESS. (*F) PT DIREC-ISPEEDCHART ER REMARKS AND SUPPLEMENTAL CODED DATA VERS (LST) (Hundrods of.Feet) (Mil.e) TO VISION (mbs.) (OF) TION (o )lO tS)S;1 Pns.) n I nta / 2 3 4 5 71 S 6 9 r10 /4 / | /g /3 7A__ 4B5 s., S /^_-_ 7g ^/ I-YL \ __1 _'9 - -i!1 ~/ G / / A/~ -_ — 8/ l// _____ I\ 4'1 47 /v /477 7/ I jQ /7 l 3 S Y 72 1 C IIN?7:1r(S E/2 S C / 69, j 3 — 4' 91 3 L I I T. o_, c ~ a I I *~ R }/~^ 3|r0 (7)T /0O, ros.9 }7 3 REM - -3 -\ SUPL________ ____ _I H 1//7 g /f - Z _/ _ Y 1 / _____/ I ____i__1-_i & R.2' 3^ E 3^'C /-1 /.. S'. /_______ ________| JC T / 9 r 3 0 (2Z S /___ < k! t_____i - i _| _|_; the U | I Air Fig. 20. S-urface weather observatiorns taken at tre U. S. Naval Air Station, Grosse Ile, Michigan, on 8 May 1960.

8 MAY 1960 SYMBOL TIME SOUNDING RELATIVE TO PLANT SITE EST Surface Azimuth Radius (Km.) 0 — 0956 Land 245~ 2KM O —— C 1005 Swamp 90~ I KM A — -A 1025 Water 140~ 16 KM 2,000 1,800 \- 920 1,600 - \ z ~ \ f, -- 930 o 1,400 - l 0_ - \ % \ B H 1,200 940 u ~~~W D9 H 1,000 a. _4 -- \ -950 -J " 800 ~~\600'-960 600 400 -I\ 970 Dry Adi/abft — a 200 980 2 3 4 5 6 7 8 9 10 II 12 13 14 TEMPERATURE IN ~C Fig. 21. Plots of the vertical temperature distribution as recorded by the aerometeorograph on 8 May 1960. 32

TABLE III HOURLY AVERAGE VALUES OF WIND DIRECTION, WIND SPEED, AND TEMPERATURE-LAPSE-RATE DATA FROM THE METEOROLOGICAL TOWER AT THE ENRICO FERMI SITE ON 8 MAY 1960 Hour Ending Wind Direction Wind Speed (mph) Lapse Rate 0100 msg 7 S 0200 msg 7 S 0300 msg 8 S 0400 msg 7 S 0500 msg 7 S 0600 msg 7 S 0700 msg 8 S 0800 msg 7 S 0900 NE 6 S 1000 N 4 S 1100 NNE 3 S 1200 SE 1 S 1300 W 3 S 1400 S 3 S 1500 S (SE)* 4 S 1600 S (ESE) 4 I 1700 S (E) 3 W 1800 S (E) 2 S 1900 S (SE) 8 S 2000 S (ESE) 10 S 2100 S (ESE) 9 S 2200 S (ESE) 9 S 2300 S (ESE) 8 S 2400 S (ESE) 9 S *Directions in parentheses are from the 56-foot level aerovane. 33

to change direction. Whether this change was due to a true sea breeze has not been ascertained. Because the analysis is not clearcut, the wind direction at the 56-ft level on the meteorological tower was added to Table III. At this lower level, the wind seems to be that of a lake breeze and in fact the 1600 EST hourly lapse rate average is an inversion followed by weak at 1700. It certainly would be possible to have a low-level inversion extending to just over 100 fto The vertical temperature structure as indicated by the aerometeorograph record on the plane shows that a weak inversion did exist over the land at 1000 EST, but there was a very weak lapse rate over the water (see Fig. 21). Since there was a NE to a N wind at the plant site at that time, the lapse rate recorded at the site was strong. It is quite possible to have a superadiabatic lapse rate in the lower 100 ft with a weak lapse or near isothermal layer above. Thus the plant area's diffusion was probably fair in the lower 100 ft but was somewhat restricted in the next 200 to 300 ft. d. Plume Characteristics.-Again aerial photographs were not taken. Definite characteristics of the plume from the smoke generator are not available because the smoke generator was not operating correctly. But the winds were so light that one burst of smoke went up straight and enveloped the entire meteorological tower, which indicates that diffusion was good in the lowest 100 ft. e. Results of Plane Sampling.-Figure 22 indicates what has already been made evident in the earlier discussion. Diffusion was good in the lower 100 ft but poor at higher levels. The counts at 4 km are sparse due to a change in the wind direction and the fact that again the aerosol generator was only putting out about 1/10 of its normal output. f. Comments on the Diffusion Pattern.-May 8 represents a day when there is a lake effect but which seems to act as a damper effect above a level of good diffusion. This is a case when there is no inversion formed immediately over the lake after a cold frontal passage because the lake surface is already warmer than the air above it. In this regard, it is more like a fall day than a spring day. It is a case of plume trapping and a case of transition in time of the lake surface temperature relative to the air above it. Fortunately, the damped diffusion condition was alleviated by changing wind directions to mix the air, and also, the upper inversion probably dissipated due to the heating effect of the sun. 34

4 KM ARC (1130-1200) 8th May'60 600 I0 0 0 o 0 0o o o o 0 0 400 0 0 0 0 0 0 0 0 0 I I I I I I I I 0 200 to 0 0 0 I 0 0 0 0 0 0 0 i i I I I I I I I I i I I z 0 2 KM ARC (1050-1125) 0 0 0 2 0 0 0 0 OQI I IO I I co 800 - I I I I I - - 1 ^ _~Z O I s 600 L 0 0 0 1 01 1 0 0 0 400 0 0 0 0 0 0 0 0 0 I II I I I I 0 0 0 6 I 0 I 0 0 0 200 -- Direction of fligt some for oil levels 0 0 0 0 15 7 19 0 0 0 0 I I I I I I I I 80 100 120 140 160 180 200 220 240 260 280 300 AZIMUTH Fig. 22. Raw counts of FP material from 8 May 1960 plotted according to azimuth and height above the lake surface.

4. EXPERIMENT OF 25 JUNE 1960 a. Synoptic Situation.-The 0700 EST map of the surface weather, Fig. 23, showed a relatively deep low-pressure area near Bagotville, Quebec. The frontal system associated with this low had already begun to occlude, so that the apex of the occlusion was located about 100 miles southeast of Caribou, Maine. The warm front ran from the apex eastward and then southeastward through Ecumseecum, Nova Scotia, and into the Atlantic Ocean. The associated cold front ran near St. John, New Brunswick, and then southwestward paralleling the U. S. east coast until it reached Cape Hatteras. From Cape Hatteras the cold front began a more westerly course through Myrtle Beach, South Carolina, and Birmingham, Alabama, finally becoming weak and diffuse north of Fort Worth, Texas. A small low was located in southern Texas causing widespread rain through the south central states. A large, cool, high-pressure center was located just south of Lake Michigan. This high-pressure area spread out across most of the central U. S. A weak cold front ran from North Battleford, Saskatchewan, southward through eastern Montana and then into northwestern Wyoming. The Detroit area was under a fairly strong northwesterly gradient which lasted throughout most of the daylight hours. b. Monroe Area Weather.-The hourly observations from Grosse Ile Naval Air Station, Fig. 24, indicated that the winds were from the northwest or west until the 1455 EST observation, after which time the winds became southerly or from the south-southwest. Wind speeds were between 3 and 7 knots during the daylight hours. Visibility was unlimited all day and there were no clouds reported at any time. The temperature reached a maximum of 77~F (25.0~C). The fact that the air was relatively dry is attested to by dew point temperature readings in the high 40's. As soon as the wind shifted to the SSW, the dew point rose due to the air trajectory over the lake. The temperature of Lake Erie was 63~F (17.2~C). Thus the temperature of the air over the lake was warmer than the lake and an inversion should be present in the lower layers. Over the land, the lapse rate was probably strong at least after the nocturnal inversion dissipated. c. Special Characteristics at Lagoona Beach.-Table IV shows the hourly average values of wind direction, wind speed, and temperature lapse rate from the meteorological tower at the plant site. The wind direction and wind speed are basically the same as at Grosse Ile. This was to be expected with the gradient as strong as it was behind the cold front. 36

STATION _.S. NAVL AIR STAT/ON GROSSE /L MICH. DATE LJ- AC /O VIS18- WEATHER SEA nI__ W IND ALTIM- OBS TP T SE SKY and CEILING ILITY Ond LEVEL D A ETER KS AND SUPPMENTAL DED DAVE TYPEI: TYINE BT.OBSTRUCTIONS DIREC- SpEEDrCHARAOETER InlS (LST) (Hunr*ds of Feet) (Mie) |TO RVISION |RESbS. (OF) (OF) TON E(Rno ^TD SUPPLIniosTA ED D (CLST)l ~arrdred g TO VISION ~ ~(mbs.a) T L (knot)IT S in$.) I. 4 5 = 6 7 8 9 / t0 // / / 14A 14 B / r -< g_. _______?4 -[_____________ _____ I__ J......;' L_____ 74.; * 1 1 I.I _o 0.:L_ 7... "/~-'r-'' - o/,~ /.__7_,?/ _ j! -o f/ 7^ ^6 I s^ i 1 / 1. _, Z. /P ____^_____ ___ ^ _ _ S _ i / _________ I!| i - 0 T | 7 77 _ _.. |__.__________ -__,i L, e,~, ~......... ~_~<:.,' c.... /.a3 d7- s~ ~ \ 6 I1,,, 7_ I. _'e0 /{_____'5o'/s-, 7/2 01'5 I2~E S //L.. 7Y _ Ie ____r Rr / 6 /i___/... _____________L4 1 ^f7__,rI ln67r ia lsz! fz,' __/ __________________ _. 13 e I/~5 1~T 1 I I s t!,' t__: __ __________, -, - _,_%___. i 2 _ Station, GLrosse Ile, Michigan, on 25 June 1960,~~~~~AO ~.....,,.........::................ ~/.m.... ~.~',q, /'~',,'

TABLE IV HOURLY AVERAGE VALUES OF WIND DIRECTION, WIND SPEED, AND TEMPERATURE-LAPSE-RATE DATA FROM THE METEOROLOGICAL TOWER AT THE ENRICO FERMI SITE ON 25 JUNE 1960 Hour Ending Wind Direction Wind Speed (mph) Lapse Rate 0100 WNW 14 I 0200 WNW 14 I 0300 WNW 15 I 0400 WNW 14 I 0500 WNW 15 I 0600 WNW 15 I 0700 WNW 15 I 0800 NW 15 I 0900 NW 16 W 1000 NW 16 W 1100 NW 15 W 1200 WNW 13 S 1300 W 12 S 1400 WSW 11 W 1500 SSW 10 W 1600 S 11 I 1700 S 9 I 1800 SSW 7 I 1900 S 6 I 2000 S 9 I 2100 S 9 I 2200 SSW 9 I 2300 SSW 9 I 2400 SSW 8 I 40

As suspected above, an inversion did exist at the plant site until sometime between C800 and 0900 ESTo Then as heating took place, the lapse rate began to change slowly, until, at 1200, the lapse rate was recorded as being strong. At 1400, the wind changed slightly so as to be from the WSW. The lapse rate then became weak, probably because warmer air was being advected aloft, By 1600 the lapse rate was recorded as an inversion. The wind had shifted so as to be from the S. One of the authors was at the Grosse Ile Naval Air Station during the day. It was noticed that, at 1530 EST, the wind shifted to the south and the temperature stopped rising while the dew point continued to rise. All these facts point to the presence of a lake-breeze-induced inversiono By 1530 the pressure gradient force must have become light enough so that a lake breeze could develop. This inversion then continued until night, when it was replaced by a nocturnal inversion. The aerometeorograph records are interesting to observe (see Fig. 25). The morning sounding over the land shows the nocturnal inversion while the overwater trajectories show the effect of the warm lake surface. At 0.5 km the inversion base is at 200 ft, whereas at 5 km the base is at 500 ft. The afternoon soundings all show a weak l3ow level inversion up to about 200 fto This is natural for the overwater soundings since the air passing over the water has been warmed by previous passage over the warm land several hours before. The land sounding taken at 1639 is an effect of the lake breeze. The cool air in the low levels has been blown in over the land from the water. The result is that the land and water soundings are quite similar in their appearance and characteristics. d. Plume Characteristics.-No aerial photographs were taken during this experiment but there were comments from the observers on the scene. During the morning, the smoke left the smoke generator and rose slightly before sinking and hitting the water. At the same time the plume seemed to bifurcate in the vertical-half of the plume hitting the water and half rising. The net result seemed to be two plumes, one on the water and one aloft. Once the smoke came close to the water, it began to diffuse rapidly. This verifies the weak lapse rate condition over the water at 0.5 km from the morning sounding. By afternoon the plume was mixing well with the surroundings air mass. After the wind shifted, no smoke was put out by the smoke generator due to a mechanical failure. e. Results of the Plane Sampling.-Figures 26 and 27 show the raw counts of FP material as collected by the airplane sampler. This was the first experiment where data were collected at 16 km. Although the wind began to shift at the plant site, the plane observer reported that the surface wind at 16 km was still westerly. This observation was based upon the direction of the smoke plume from lake freighters below the plane. Although the aerosol generator had been repaired since earlier experiments, the output of the generator was still only about 40% of its rated outputo However, all radii of the sampling pattern look goodo Counts were made from 60-1000 ft above the water on the 2- and 4-km 41

25 JUNE 1960 TimeSoundin relative to t site Sounding relative to plant site Symbol Est. Surface Azimuth Radius (KM) Symbol Est. Surface Azimuth Radius (KM) 0 —- 0708 Land 3000 IxKM 0-0 1639 Water 1200 4KM D —-o 0755 Water 120~ 0.5KM 0 —- 11650 Water 120~ I KM A —— 10816 Water 1400 5KM r — -1657 Land 300~ 4KM 2000 -940 2000 - -940 \ \\4\ \ 1800 95 1800\ 9 \ \ hi ~-950' -950 1600 oo \100 z1 \ \' i z\ \ - 600 \, ~ D \ 4 U -960 0 960 1400 1400 > ~ o m I 1200- co C 1200~~~~~~~m ~970 970o I - w 1000 \ u 1 000 1 3 2 209804 w \ 980 -i. 25.Plta.- \ a. 800 \' 80 w W 600 990 600 99 400 - ^y>400 - 1000 rya 1000 200- 200 0!I I I I 1100 I I I I I I 00 13 14 15 16 17 18 19 20 21 22 23 19 20 21 22 23 24 25 26 27 28 29 TEMPERATURE IN ~C TEMPERATURE IN ~C Fig. 25. Plots of the vertical temperature distribution as recorded by the aerometeorograph on 25 June 1960. 42

4 KM ARC (0954-1103) 25/h June'60 1000 - I.1'I 2 0 2 1000, 0, II 0 0 I 4 I 2 800 0 10,0, 600 I 0 I 32 2 0 3 I I I I I I 400 33 |, n3 I, 3 0 3 3 < 0I 0 0 I 200 I I I I LI. 200o w 3 0 2 4 I I II I I II 100 2 KM ARC (0831-0904) 2 3 3, 0 >_ 8000 I I i I 0 800 1, 0, 4, o Lii 600 0 3 17 10 0 400 Direction of flight 16 27 2 0 same for all levels 20 2 0, 59, 1 0 200 1 0 0 14 0 I94 4 2 20 40 60 80 100 120 140 160 180 200 AZIMUTH Fig. 26. Raw counts of FP material from 25 June 1960 at 2 and 4 km plotted according to azimuth and height above the lake surface.

I1,600 16 KM ARC (1430-1650) 25th June 60 Direction of flight 8. 100. I, 1,0,0 0 1, 1,400 1,200 1,000 2 0, 6, I,,, 0. I0, 00, --- 8,000 -- I 6 3.3 0 0 I 4 2 I 0 I 800 -,6,3,3 0 0, 1 4,2, 1,0,1, 600 - 6, 0 0 2 0, 0 00,0 0 400 0 Z -- z >61,3 0, O, 03 01212120000 C 200 I 2 I;2 I 2 0; 0 I w w 1,60 8 KM ARC (1210-1350) iL Direction of flight 0 0 22 29 2 0 0 0 LU -J w 1,200 1,000 - [, I 0 12 0 0.. 0 0 1,000 - 800 -- 0 0 600 4 24 2 0 00 0 400 0 0 54 I 0 0 0 2 00 ^ 226 2 0 0 0 200 - 20 40 60 80 100 120 140 160 180 200 AZIMUTH Fig. 27. Raw counts of FP materials from 25 June 1960 at 8 and 16 km plotted according to azimuth and height above the lake surface. 44

arcs and from 60-1500 ft on the 8- and 16-km arcs. Indications are that the plume had shifted when the 16-km arc was sampled and that only one side of the plume was really sampled. fo Comments on the Diffusion Patterns. -It was hoped that this run would show a definite inversion over the lake for a long distance in which vertical diffusion would be markedly damped and in which horizontal diffusion would take place at normal rates. This was not the case, and in fact diffusion appears to be good all day. However, a low-level inversion did exist over the water late in the afternoon.

III. SUMMARY OF EXPERIMENTS It is appropriate at this time to review the past experiments to assess their value not only in computing diffusion parameters but also in determining the many minor features which together make up the diffusion meteorology of an area. As in all research, every experiment was not a complete success in all respects. During one experiment, the aerosol generator might not work as efficiently as it should. During another, there may have been airplane difficulties. Then when all equipment was operating properly, the wind would shift. However, there is some information that can be gotten from each experiment. Table V snummarizes the eight successful experiments that have been reported on in the first two progress reports. The initial planning called for experiments to be conducted during each. of the four seasons of the year. This has been accomplished. Sampling has taken place from right after sunrise until just before sunset under various meteorological conditions. When considering the enormity of such a program and the restrictive manpower conditions, the experiments turned out to be quite well balanced. If one major fact could be picked from all the experimental evidence, it would be that the effect of Lake Erie on the air-pollution potential of the land areas immediately adjacent to the lake is major. This is not a new idea, but the diffusion experiments have made this fact more evident and better understood. During days when diffusion is normally good at land stations (that is, a strong lapse rate due to solar heating), the lake shore may be affected by a lake breeze which causes an inversion to form. Such inversions naturally inhibit diffusion in the area. On other days, when the air is cooler than the lake temperature, diffusion is enhanced over the lake. The situation of warm air over a relatively cool lake still remains to be fully investigated. In conclusion, then, it may be said that this series of eight experiments when fully analyzed will not only have been useful for the contracting agency, but also educational for the field of meteorology as a whole, This experimental work in an area of land and lake interplay has helped to cast some light on the problem of diffusion in transitional states. 47

TABLE V SUMMARY OF EXPERIMENTS AT THE ENRICO FERMI NUCLEAR POWER PLANT LAGOONA BEACH, MICHIGAN Date of Season Time of Lapse Rate at 1 Comments Relative to Value of Equipm~-ent Remarks Experiment of Year Sampling Meteor. Tower EupSutton's Equations Experiment 5 August 1959 Summer 0756-1051 W becoming S None Missed plume Not usable ~_________________ ~__ _________Aerial photographs __________ Run No. 1 0754-0956 W None Missed plume at one 6; Augustc 1959 Su mme r -- -i n oGood6 Augus 195 Summ Run No. 2 level. Some meander _________ ____1115-1228 W_ None _________ 27 November 1959 Fall 1206 1552 S becoming W None Some meander Good 28 November 1959 Fall 1517-1646 becomin W None Missed plume at some usable _____________ ______ __ ~___ ___ ___~______ levels, sampled 8 km____ N;o ne 4 February 1960 Winter 1420-1606 W becoming I None Good 4P:7- _______ ^ _____________________________Aerial photographs Smoke generator and 5 April 1960 Spring 1150-1557 I aerosol generator not None Good _______________~_~____ ____ ____working properly Smoke generator and Appears to be a trap8 May 1960 Spring 0956-1207 S aerosol generator not b Good ping situation _________________ ________working properly4 Sampled out to 16 km. Aerosol generator Wind shift caused only 25 June 1960 Summer 0744-1645 S becoming I not up to capacity Wnd sh caused Good 1/2 plume to be sampled _____~~~_______________ ~_________ outputat 6 km ____ a-t 16S km

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