Surface Water Temperatures of the Canadian Atlantic Coast

Bv H. B. Heqrev

Atlantic Biological Station

(Receiveil Jor publication June 24, 1939)

ABSTRACT

Monthly mean surface water temperatures, based on observations from 1926 to 1935'are used to determine normal monthly mean temperatures for eight points on the CanadianAtlantic coast. Sine curves are found to fit the data for all points, with one exception. Thegeneral type of temperature curve determined by daily observations divides the regions ofobservation into those represented by a smooth curve, those by an erratic type, and those showingsharp but regular changes in temperatures from day to day.

INTRODUCTION

Surfacd sea water temperatures have bebn determined, twice daily, at St.Andrews, N.B., for several years past (1921-1935 inclusive). Similar observationswere inaugurated at Halifax, N.S., in 1925 and complete data are available forthe period 1926 to 1935 inclusive. In 1929, the Biological Board of Canada,cooperating with the North American Council on Fishery Investigations, madearrangements for similar observations at Grand Manan and Isle Haute in thebay of Fundy, Lurcher lightship off Yarmouth, N.S., and at Sambro island,Sable island, and Scatari island, off the south coast of Nova Scotia. In 1g30,further arrangements were made for observations at Entry island of the Magdalengroup, at North point, P.E.I., at cape Gasp6 and St. Marys island in the gulfof St. Lawrence. In 1932, ariangements were made for seasonal observationsat Mutton bay on the north shore of the gulf of St. Lawrence, and at Hallsharbour in the bay of Fundy. In 1935, arrangements were made for observationson board the Halifax lightship. The locations of these points are indicated infigure 1.

In 1931 the observations at cape Gasp6 were discontinued, and those atIsle Haute in 1934, while those at North point were discontinued in 1935.

This paper constitutes an analysis of the data for the period 1926 to 1935.

METHODS

The general procedure at all points was to determine the surface sea watertemperatures twice daily (usually at 8.00 a.m. and at 4.00 or 5.00 p.m.). Thepoints of observation were chosen, in as far as possible, so that the observationswould have some significance for the region in general. With this in mind, theobserving stations were usually located on the open coast in exposed positions.The procedure, outlined for the observers, was to obtain a bucket (wooden) of

378

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water and to read the calibrated immersed thermometer to the nearest tenth

of a degree (in some cases to the nearest quarter). In most cases, the pbservationswere made and recorded with admirable appreciation of the need for care and

accuracy.In the annual analysis of the data, the daily mean temperatures were

determined for each station and illustrated graphically. The monthly mean

FrcuRE 1. Canadian Atlantic coast with locations of organized stations for the observation of

surface seawater temperatures.

temperatures were calculated and recorded in tables (for St. Andrews, GrandManan, Halifax, Sambro Is., Sable [s., Scatari Is., Entry Is., and St. Marys Is.,see table I).

DAILY MEAN TEMPERATURES

To illustrate the nature of the surface water temperatures of the variousregions, the daily mean temperatures for 1932 are plotted in figure 2. These

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Tenr.B I. Monthlv mean temperatures in degrees Centigrade of surface water at varrous coastalstations

Sr. ANonBws

J . n . r . 8 4 . 2 - 1 . 2 1 . 6 0 . 1 0 . 5 1 . 6 2 . 7 2 . 2 1 . 3 2 . 9 3 . 0 2 . 6 - 0 . 4 0 ' 0 r . 2F e b . 0 . 3 - 0 . 5 - 1 . 7 - O . 3 0 . 0 - 1 . 1 0 . 3 r . 4 1 . 3 - { . 3 1 . 0 0 . 7 1 . 5 - L . 4 - 0 ' 8 0 . 0M a r . 1 . 8 0 . 5 - 1 . 7 1 . 2 1 . 5 - 0 . 3 1 . 3 1 . 8 1 . 7 0 . 7 L . 7 0 . 7 7 . 4 - O . 5 - 0 . 4 0 . 8A p r . 4 . 2 3 . 2 1 . 0 3 . 5 3 . 7 1 . 6 3 . 4 3 . 8 3 . 1 3 . 3 3 . 8 3 . 3 3 . 7 3 . 4 2 ' 5 3 . 2M a y 7 . 7 6 . 3 5 . 7 6 . 4 6 . 9 5 . 3 6 . 2 6 . 8 6 . 8 6 . 8 6 . 6 6 . 3 6 . 9 6 . 5 5 . 3 6 . 4

J u t r . 9 . 6 9 . 1 7 . 6 8 . 2 8 . 9 8 . 0 9 . 1 9 . 9 9 . 4 l O . 2 9 . 3 9 . 0 9 . 6 9 . 1 9 . 3 9 . 1

J , r l . r 2 . O I 2 . 2 1 0 . 2 1 1 . 1 I l . 4 l l . 2 1 1 . 4 1 3 . 0 l l . 7 1 2 . 3 L 2 . 4 l l . 4 1 1 . 8 1 1 . 6 l 2 ' O l l . 7Aug. 12 .9 12 .6 10 .9 12 .2 L2 .3 12 .2 12 .4 13 .5 12 .6 L3 .2 13 .4 l3 . I 12 .7 12 .7 l3 . l l2 '7S e p . l 3 . O L 2 . 2 1 1 . 4 1 1 . 9 l l . 7 l 2 . l 1 1 . 8 1 2 . 4 1 2 . 5 1 3 . 2 1 2 . 7 L 2 . 9 1 2 . 3 l 9 . L 1 2 . 0 l 2 ' 3O c t . l l . 2 9 . 4 1 0 . 0 1 0 . 3 8 . 6 1 0 . 4 1 0 . 8 1 0 . 6 1 0 . 2 1 1 . 3 1 0 . 8 1 1 . 4 1 0 ' 5 1 0 ' 4 1 0 . 1 1 0 . 4N o v . 6 . 8 5 . 7 7 . 5 7 . 3 6 . 3 7 . 4 8 . 6 7 . O 7 . 1 8 . 4 8 . 6 7 . 6 6 . 0 7 . 6 8 . 0 7 ' 3D e c . 3 . 2 1 . 7 5 . 3 3 . 3 3 . 1 3 . 0 5 . 0 4 . 9 2 . 8 4 . 6 4 . 7 4 . 3 1 . 6 3 . 3 3 . 7 3 . 6

M e a n 7 . 0 6 . 0 5 . 4 6 . 4 6 . 2 5 . 9 6 . 8 7 . 3 6 . 7 7 . 1 7 . 3 7 . 0 6 . 7 6 . 3 6 . 2 6 ' 6

S.W. Hrlo, Gn.a.no M.e.NnN

. c SE - 6r c6 <r ro cg N @ or o i N co <r !a E

S EH E E ES EE E EE E EE E 2

o9 d

c o o 6 r c o < r r o i t r€ S E E E E E E ;ba

Jan.Feb.Mar.Apr.M a y 4 . 6

J u n . 7 . 2

J,r l . 8. IAug. 10. 1S e p . 1 1 . 0O c t . L 4Nov. 7 .4D e c . 4 . 1

2 . 4 2 . 8 4 . 71 . 3 2 . 2 2 . 52 . 4 2 . 7 2 . 34 . 7 4 . 0 3 . 77 . 0 5 . 5 6 . 08 . 5 8 . 1 8 . 0

1 0 . 6 1 0 . 0 9 . 31 1 . 5 1 1 . 6 1 1 . 31 1 . 7 1 1 . 5 1 1 . 8r r . 2 l o .2 10 .99 . 5 8 . 9 8 . 06 . 0 5 . 9 5 . 6

4 . 7 2 . 03 . 3 - 0 . 13 . 0 1 . 03 . 7 2 . 96 . 0 5 . 78 . 2 7 . 5

to .2 9 .71 0 . 7 1 0 . 91 0 . 8 1 1 . 8l0.2 10.47 . O 8 . 44 . O 5 . 0

2 . 3 3 . 31 . 1 1 . 8r . 2 2 . O2 . 5 3 . 45 . 0 5 . 67 . 6 7 . 9

1 0 . 1 9 . 91 1 . 1 1 1 . r1 1 . 0 L t . 49 . 9 1 0 . 38 . 4 8 . 15 . 3 5 . 2

Mean O . .6 . 36 . 36 . 87 . O6 . 87 . 2

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Table I (continued,)

Her.rrex

t r c c ) t - @ o r o i c !o c . r 6 l N 6 l c o c o 6 6

a i i d d i i i

i o . O i c . l c oo 6 l c € m c o c a c a

a

$ r o i lm m A

I

J a n . O . 7Feb. -0 .3

Mar . 0 .3Apr . 1 .8Ma-v 5.0Jun. 7 .9

Ju l . r l .2Aus. 14.7Sep. 14.4Oct. 11 . 6Nov. 8 .2Dec. 4.0

2 . 5 3 . 00 . 5 0 . 60 . 8 r . 22 . 7 3 . 25 . 9 6 . 79 . 5 1 1 . 0

t4.7 t+.514. t 16.212 .9 16 .013.2 10.99 . 9 6 . 65 . 5 4 . 3

2 . 2 1 . 80 . 6 1 . 2o . 7 2 . 32 . 7 4 . 25 . 8 7 . 2

1 1 . 4 1 3 . 812 .5 t 4 .L13.2 r5.41 4 . 6 1 6 . 110 .9 13 .77 . 2 8 . 23 . 3 3 . 9

2 . r 2 . 8 4 .1 . 6 0 . 9 2 .2 . 0 1 . 1 1 .4 . 2 3 . 0 3 .7 . 7 6 . 2 5 .

t 2 . 6 1 0 . 5 1 1 .1 6 . 3 1 2 . 8 1 5 .16 .0 16 .5 15 .15 .4 15 .5 13 .1 2 . 0 1 1 . 5 1 2 .8 . 9 7 . 6 7 .4 . 8 5 . 1 2 .

0 . 2 r . 4 2 . 1- o . 4 0 . 8 0 . 8

0 . 9 1 . 1 1 . 23 . 9 2 . 8 3 . 26 . 6 5 . 8 6 . 3

1 0 . 5 1 2 . 3 1 1 . 11 5 . 0 1 3 . 5 1 4 . 075.2 76.2 15.3'17 .5

13 .2 14 .91 2 . 3 1 1 . 6 1 2 . 08 . 7 1 0 . 0 8 . 34 . 4 5 . 7 4 . 4

M e a n 6 . 6 7 . 7 7 . 5 7 . 1 8 . 5

SeMsRo Islero

7 . 87 . 97 . 97 . 88 . 6

d

> br o t r

I a n . 0 . 6Feb. -O.2

M a r . 1 . 1Apr . 2 .9M a y 2 . 4 5 . 5

J u n . 9 . I 8 . 4Ju l . 7 .7 10 . 1Aus. 10 .8 14 .8Sep. 13 .5 16 .2Oct . 10 .0 12 .9N O V . l . D t . D

Dec. 2 .8 3 . I

2 . 4 r . 70 . 5 - 0 . 61 . 0 - 0 . 43 . 5 2 . l6 . 4 5 . 2

1 1 . 6 8 . 31 3 . 3 1 1 . 41 6 . 3 1 5 . 81 5 . 3 1 6 . 0t2 .2 10 .98 . 4 7 . 64 . 1 4 . 4

4 . 0 0 . 22 . 6 - 0 . 41 . 9 0 . 93 . 4 3 . 95 . 8 6 . 6

1 1 . 3 1 0 . 5r 5 . 2 1 5 . 015 . 5 t 5 . 21 3 . 5 1 7 . 512 .2 12 .37 . 5 8 . 72 . 8 4 . 4

t . 70 . 30 . 73 . 05 . 9

1 0 . 31 3 . 5r5.71 5 . 01 1 . 68 . 13 . 8

Mean 6 .9 7 . 9 6 . 9 8 . 0 7 . 9 t . o

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Table I (conlinueil)

Sesr,e IsLANo

Jan.Feb.Mar.Apr.MayJun. 10 .0

Jul. 14.2Aug. L7 .4Sep. 16.7Oct . 13 .4Nov. 8.9Dec. 3 .5

Ei e i Fx x h A

i r o t r

C o l o i 6 l c oo c \ c o c o c o c o

A H H

dPq o o H c-t co <r ro L:tr€ S E E E E E E .51 1 ; H H H d H H I O E

1 . 6 2 . 4 2 . 50 . 9 1 . 5 - 0 . 51 . 5 3 . 1 1 . 13 . 9 5 . 6 5 . 36 . 0 8 . 9 8 . 7

10.7 12.2 LO.716 .0 16 .8 14 .718.3 t9.2 17.716.8 17.0 15.21 3 . 0 1 2 . 7 1 1 . 69 . 0 9 . 15 . 3 4 . 5

3 . 1 1 . 5 0 . 7 2 . 01 . 9 L . 2 0 . 8 1 . 01 . 8 r . 2 0 . 5 1 . 54 . 0 3 . 7 | . 4 4 . O7 . 2 7 . 5 4 . 9 7 . 4

10 .4 10 .5 8 .3 10 .414 .3 14 .9 12 .6 14 .717 .R 18.2 16. 8 17. E16 .3 18 .0 17 .2 16 .713 .7 13 .9 t 2 .3 12 .88 . 2 9 . 9 9 . 4 9 . 22 . 9 3 . 1 3 . 5

Mean 8 . 48 . 68 . 49 . 48 . 6

Scerenr Isr.eNo

Jan.Feb.Mar.Apr.M a y 2 . 3J u n . 7 . lJu l . 13 .1Aug. 16 .5Sep. L5.4Oct. l2.ONov. 6.3Dec. 1 .0

- 0 . 5 0 . 4 0 . 5- 1 . 5 - 1 . 3 - 1 . 4- 0 . 9 - 0 . 7 - 0 . 9

0 . 6 1 . 8 0 . 43 . 4 4 . t 3 . 68 . 4 8 . 5 7 . O

14 .1 13 .3 t 2 .217 .5 L7 .3 17 .016.4 15.8 t5.2t t . 4 10 .7 11 .56 . 4 7 . 4 7 . 53 . 3 3 . 3 3 . 8

1 . 0 - 1 . 1- 0 . 4 - 1 . 1- 0 . 9 - 1 . 0

0 . 0 - 0 . 73 . 9 3 . 27 . 5 7 . 1

13.2 L4.217 . r 17 .71 5 . 8 1 7 . rLL .7 t 2 .35 . 9 7 . 70 . 9 2 . 7

- 0 . 1 0 . 1- 1 . 1 - 1 . 1- 1 . 0 - 0 . 9-o .7 0 .2

0 . 3 3 . 05 . 9 7 . 2

r3.2 L3.21 7 . 5 t 7 . 3t5.2 15.81 1 . 3 1 1 . 57 . 9 7 . 34 . 3 3 . 0

Mean 6 . 46 . 16 . 56 . 36 . 36 . 76 . 6

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Table I (continueil)

ENrny Isr,eNo

E o i c \ r mo m c € c € c 6= o o ) o o r

(g

j p i FH 5 > ' 6i H r l : q

-c€ ('.E Q - t N c o < r r o j : Eo 6 t . C O C O

a i i i t o C

J.tr.Feb.Mar.Apr.May 6 .0J u n . 1 1 . 6J" l . 17 .1A'ug. I8.0Sep. 15 .3Oct. 11 .0Nov. 5 .6Dec. 2 .L

6 . 6 4 . tr r . 2 9 .114 .6 13 .917 .5 17 .714 .8 15 .9L 7 1 1 . 06 . 3 5 . 20 . 3 0 . 2

4 . 3 3 . 59 . 3 8 . 8

14.1 14.517.5 17.Ot4.2 16.810 .0 10 .72 . 5 5 . 2

- 1 . 2 - 0 . 6

-1 .8 ( i ce)- 1 . 8_ 1 . 9 , .

3 . 6 4 . 49 . 8 9 . 6

14.6 14 .31 8 . 4 1 7 . 614.4 15.29 .7 LO.26 . 1 5 . 11 . 1 0 . 0

Mean

Sr. Manv's Ist lNo

Jan.Feb.Mar:Apr.MayJnn.Ju l . 10 .9Aug. 11 .3S e p . 1 1 . 0Oct. 6.5Nov. 3 .3Dec. -0 .4

- 1 . 5- t .4

3 . 3 2 . 27 . 2 6 . 29 . 5 1 0 . 1

1 3 . 8 1 1 . 91 1 . 8 1 0 . 76 . 4 5 . 83 . 6 3 . 01 . 1 - 0 . 7

-1.6 -1.7 -1.8 -1.6 (approx.)-1 .6 -0 .5 - r . 7 - t . 4 ' '- 0 . 8 - 0 . 3 - 1 . 6 - 1 . 3 ' .- o . 7 0 . 4 - 1 . 0 - 0 . 5

0 . 9 1 . 0 2 . 1 1 . 95 . 2 7 . 4 6 . 58 . 4 9 . 1 9 . 3

6 . 9 8 . 3 1 3 . 0 1 0 . 89 .1 r0 .0 10 .6 10 .47 . 3 6 . 2 5 . 4 6 . 22 . 3 3 . 2 3 . 2 3 . 1

- 1 . 5 - 0 . 8 0 . 0 - 0 . 4

Mean

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plotted temperatures may be considered as of three different groups as follows:

Those represented by a smooth curve, indicating that gradual temperaturechanges take place from day to day. Such a curve is typical of points in the

Frcunp 2. Daily mean surface seawater temperatures at various points for the year 1932:

bay of Fundy, and is best exemplified by the plotted temperatures for St'

Andrews. In such a case, although general climatological conditions determine

the general trend of temperatures, mixing and upwelling, due principally to

tidal action, prevent extreme daily variations. Hence, the resultant plotted

E,.tto

o

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15,o5o

6

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It,o5o

,t,o5o

,5,o5o

t5lo5o

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/5,o5o

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o

"c/tfo5o

/5/o5o

/5/o5o

/5,o5o

t5,o5o

/5to5o

/5lo5o

/5,/o5o

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/o

o

/5/o

o

Jen. Fe6. f'1ar A,or /4af Juo- Jul Aug. ,Sep. Ocl. Nou. Dec.

E@ II@

- f

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385

temperatures approximate quite closely to a smooth sinusoidal curve. This

same tidal action, producing mixing of waters of the various levels, resutts in a

comparatively small annual variation in temperature, with summer temperatures

comparatively low, and winter temperatures comparatively high with little ice

formation.Those represented, by an erratic type oJ curae showing sharp and irregular

temperature changes taking place from day to day, particularly during the

warmer months of the year. Such changes are typical of points on the south

coast of Nova Scotia, and are well exemplified by the plotted temperatures for

Halifax, Sambro island, and Scatari island. Such sharp and erratic changes in

temperature are due to the presence of a very cold sub-surface body of water

which is readily brought to the surface under certain conditions of wind and

atmospheric pressure.Those represented, by a jagged bul' otherwise regul,ar curue showing sharp, but

otherwise regular, changes in temperature from day to day. Such a curve is

typical of points in the shallower portions of the gulf of St. Lawrence, and is

well exemplified by the plotted temperatures for North point and Entry island.

In the general case, climatological conditions, coupled with the shallowness of

the areas in which the stations are situated, are responsible for the large dailyvariations. -The plotted temperatures for St. Marys island furnish a curve of

this type also. The abrupt changes in temperature that occur here are probably

due, in the main, to variation in the nature of the water movements through

Belle Isle strait.

NORMAL MONTHLY MEAN TEMPERATURES

Normal monthly mean temperatures have been determined for a numberof selected points of observation. Fifteen year data (1921 to 1935 inclusive)

were used to determine a normal monthly mean temperature for St. Andrews,

ten year data (1926 to 1935 inclusive) were used to determine a normal monthly

mean temperature for Halifax, while five year data (1931 to 1935 inclusive)have been used to determine normal monthly mean temperatures for GrandManan, Sambro island, Sable island, Scatari island, Entry island, and St.Marys island. These calculated normals are furnished in table I.

In most cases, these normal monthly mean temperatures for a given location,

when plotted, are found to approximate to a sine curve. This is illustrated in

figures 3 and 4. The sine curves found to fit the data in the various localities

are as follows:z ' ( r*1.8)

St, Andrews t : 6.4 - 6.5 sin -__

rk I l . 4 )Grand Manan / : 6.6 - 5.0 sin -*;*-

zr'(**1.8)St. MarYs island Y : 3.3

I 7.2 sin

-

Entry island ! : 5.0 - 11.5 "i.19{-1I)

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\\t \\14

p\t

\\q)

Uq

c)s\*

ST ANDREWS

3 1 4 1 5 1 6 l 7Fe6.l/Yac l,4p* lTuTurlJun. lJul 14u9. lSep. loct lNozlDec. lJon. lr.t. lt/o-

ST MARY,S IS .

Frcunr 3. Normal theoretical temperature-time curves for St. Andrews, Grand lManan, St.J. F

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\VttI\t

q

\J

blJ

\t

G. MANAN

4 1 5 1 6Jan. t'Feb.1'/1az r'4ay lJun. lJul

zz0ec

fotVou

9Ocl5.A.

7

4u?

E N T R Y I S .

Marys island, and Entry island.

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HALIFAX

7 | A | 9 l l o 1 1 1'aD. lFe6. l/4'a. l,4p- lt/eylJun. l-rut lAug. lSep. lOct lryov.lDe".l-reo. lFed.

\\, 0\uc,

t\t

\;.o

i4ir

to\t

Frcunp 4. Normal theoretical temperature-time curves for Halifax, Sambro island, Sabte

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t\'\\q)s\t

I

.q,\J

u)A)t\t

SAMBRO IS .

bn. I Fe6. lHbc I Ap. I klay ltun. I tu/.

SCATARI IS .

island, and Scatari island.

lug lSep. locl. lMov. lDecJ. F

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Halifax

Sambro island

Sable island

y:b.r- z.4sin4a#9z( r *1 .8 )

y :7 .8 - 7 .6 s in - -

y : e.o - 8.1 sin 4+LA

r(xlr.5)y : 5.8 - 10.6 sin U

(spring, summer, and autumn)r ( x {1 .5 )

! : 5.4 - 6.9 sin -F

(winter, spring, and autumn)

Scatari island

With the exception of Scatari island, the data of which cannot be fitted by asingle sine curve, the data from other points may be very closely representedover the greater part of the year, by an equation whose general form is

! : A-B s in %r(x* e)

Twhere y is the normal monthly mean temperature in degrees Centigrade,

.4 is the mean annual temperature,B is one half the annual amplitude,

,, x is the time in months, ande is the phase or lag in months.

DISCUSSION

In the case of those areas where ice formation is always a feature throughoutthe winter months (St. Marys island and Entry island), the portion of the curvesrepresenting the colder months of the year are more or less theoretical, andindicate the probable trend of water temperatures if no change of state tookplace (i.e. if the water did not freeze). The phenomenon at Scatari island,wherein the curve fitting the winter data partakes of the nature of that forSambro island on the south coast of Nova Scotia, and the curve fitting thespring, summer, and autumn data corresponds to that for Entry island in thegulf of St. Lawrence, is of considerable interest. On account of the comparativelyshallow depth and the temperature of the continental air, ice formation in thegulf of St. Lawrence is pronounced in the region of Entry island during thewinter months. As opposed to this, conditions necessary for ice formation aremodified, to some extent, on the open south coast of Nova Scotia, due chieflyto the upwelling and mixing of warmer sub-surface waters. With ice formationnot a characteristic feature of the Scatari island region, the winter surfacetemperature data may be fitted by a curve similar to that for the Sambro islandregion, on the south coast of Nova Scotia. During spring, extensive ice move-ments from the gulf of St. Lawrence to the Scatari island region offset theeffects of vernal warming, with the result that the surface water temperaturescorrespond to those within the gulf. During summer and autumn, both the

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temperatures and salinities of surface waters in the Scatari island region reflect

the effect of water movements from the gulf to a greater degree than do those

in the Sambro island region. Hence. it is to be expected that the curve fitting

the spring, summer, and autumn data for Scatari island approximates that for

Entry island.An examination of the curves and plotted results in figures 3 and 4 indicates

that, normally, the higher summer temperatures are experienced at Sable island(17.8). The other points, listed in decreasing order of magnitude are Entry

island (17.6), Scatari island (17.3), Sambro island (15.7), Halifax (15.3)' St.

Andrews (12.7), Grand Manan (11.4), and St. Marys island (10.8)'

Normally, the lower water temperatures are experienced at Entry island

and St. Marys island, where ice exists throughout the winter months and water

remperatures are as low as -1.8'C. The other points, l isted in increasing

order of magnitude, are Scatari island ( -1.1 with considerable ice), St. Andrews

(0.0), Sambro island (0.3), Halifax (0.8), Sable island (1.0), and Grand Manan

(1 .8 " C . ) .The observed annual amplitude in the monthly normals (the highest

monthly normal minus the lowest monthly normal) for each point is listed in

order of magnitude as follows: Entry island (19-4), Scatari island (18.4), Sable

island (16.8), Sambro island (15.4), Halifax (14.5), St' Andrews (12.7)' St.

Marys island (12.6), and Grand Manan (9.6).

SUMMARY

Monthly mean surface water temperatures are tabulated for eight points

on the Canadian Atlantic seaboard.Daily mean temperatures for the year 1932, for several points on the

Canadian Atlantic seaboard are plotted to illustrate the daily variation in the

water temperatures of various regions. According to the general type of tempera-

ture curve, the regions are divided into (a) those represented by a smooth curve'(b) those represented by an erratic type of curve, and (c) those represented by

a curve showing sharp but otherwise regular changes in temperature from day

to day.Normal monthly mean surface water temperatures are calculated for each

of the eight points.Sine curves are found to fit the data for all points with the exception of

Scatari island. The curve fitting the winter data for Scatari island is of the

nature of those for points on the south coast of Nova Scotia, while the spring,

summer, and autumn data may be fitted by a curve similar to that of Entry

island in the gulf of St. Lawrence.Normally, the higher summer temperatures are experienced at Sable island,

and listed in decreasing order of magnitude are Entry island, Scatari island,

Sambro island, Halifax, St. Andrews, Grand Manan, and St' Marys island.

Normally, the lower winter temperatures are experienced at Entry island

and St. Marys island, where ice exists throughout the winter months. Listed in

increasing order of magnitude are Scatari island, St. Andrews, Sambro island,

Halifax. Sable island. and Grand Nlanan.

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