Urban climate, Halifax area and its relation to the Atlantic Regional laboratory

(1)

Publisher’s version / Version de l'éditeur:

Technical Note (National Research Council of Canada. Division of Building Research), 1970-09-01

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.

https://nrc-publications.canada.ca/eng/copyright

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.

Questions? Contact the NRC Publications Archive team at

PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.

NRC Publications Archive

Archives des publications du CNRC

For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.

https://doi.org/10.4224/20338392

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

Urban climate, Halifax area and its relation to the Atlantic Regional

laboratory

Robson, D. R.

https://publications-cnrc.canada.ca/fra/droits

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

NRC Publications Record / Notice d'Archives des publications de CNRC: https://nrc-publications.canada.ca/eng/view/object/?id=694f9e46-935e-4c64-9952-74a2c081819e https://publications-cnrc.canada.ca/fra/voir/objet/?id=694f9e46-935e-4c64-9952-74a2c081819e

(2)

No.

NOTE

TEClHIN ][CAIL

NATIONAL RESEARCH COUNCIL OF CANADA

DIVISION OF BUILDING RESEARCH

ｾ

55Z

PREPARED BY D. R. Robson CHECKED BY D. C. T. APPROVED By N.B.H.

DATE September 1970

PREPARED FOR Inquiry and Record Purposes

SUBJECT URBAN CLIMATE, HALIFAX AREA AND ITS RELATION

TO THE ATLANTIC REGIONAL LABORATORY

Weather'records from the Department of Transport's weather station in Halifax are used for the outdoor exposure site at the Atlantic Regional Laboratory. A 1954 report of DOT's Meteorological Division, showed that summer daytime temperatures varied considerably from point to point within the city of Halifax.

*

Because of this it was decided to establish the differences in urban climate between the two sites.

The weather recording facility for Halifax is located at the Shearwater Air Station in Dartmouth; this is

4t

miles east and 1

t

miles south of the ARL (Figure 1). The data from this station is published monthly under the title of the Halifax Weather Report. Weather information is taken from that publication for use in reports on the performance of building materials at the ARL exposure site.

In May and June of 1968 and in August and September of 1969,

the wet and dry bulb temperatures were recorded at ARL. The

tem-perature sensing devices were installed in a standard Stevenson Screen on the roof of the ARL building. A shortage of personnel to

*

Some Local Temperature Variations in Halifax,

May to September 1953, by Reid V. Dexter. CIR--Z473, Tec 184- Z3 Apr 1954.

(3)

2

-service a proper weather recording operation necessitated the use of thermocouples in place of the standard mercury- or alcohol-type

glass thermometers. The thermocouples were installed in closed-end

glass tubes partially filled with a low vapour pressure oil. The one for the wet bulb reading had a standard wick around the tube which was kept wet by a water reservoir. The fan in the draft tube was interconnected through the ｴｾｭｰ･ｲ｡ｴｵｲ･ recorder in such a way that it came on five minutes before the temperatures were recorded and shut off immediately following the recording. Temperatures were recorded hourly and once a week a check was made with a battery-operated psychrometer at the same time that a temperature reading was being recorded.

The check with the psychrometer revealed that the wicking had to be changed weekly or it became so clbgged with dust that the

wet bulb temperatures recorded were not correct. When the wick

was kept clean there was less than 10

difference between the readings. For most purposes this method of obtaining wet and dry bulb readings was sufficient.

Although wet and dry bulb temperatures were recorded hourly, only readings at 0200, 0800, 1400, and 2000 hr were compared with

those in the Halifax Weather Report. The maximum and minimum

temperatures were obtained by visual scanning of each 24-hour period

of recordings. A daily mean temperature was obtained from the

maximum and minimum dry bulb temperatures. The relative humidity

was obtained from the readings of wet and dry bulb temperatures recorded at the specified six-hour intervals and the daily average ascertained.

The daily mean temperature is recorded in the Halifax Weather Report as well as relative humidity values for 0200, 0800, 1400 and

2000 hr. The daily average relative humidity was calculated and compared with the ARL average.

DATA SUMMARY

Figures 2 and 4 show the summarization of data compiled by using daily averages for the ARL site and the DOT Weather Station.

(4)

3

-The air moisture content calculated from the temperature and relative humidity has been recorded on Figures 3 and 5.

OBSER VAT IONS

Recordings of relative humidity and temperature at ARL and at the DOT Weather Station in Shearwater show very little differences when daily averages are compared.

It would appear that the Halifax Weather Record may be used, without serious error, as a weather record at the ARL exposure site. Unfortunately, there is no equipment at the ARL site to record precipitation, wind, and sunshine, all of which have their effect on the weathering of materials. It is suggested that, as the temperature and humidity records are similar for both sites. there should be very little difference in the precipi-tation, wind and sunshme records for each site.

(5)

ｾ , ,

.

ＢｾｾＧｾｹ

Poi", Part Pp,,,, Pll6U"If

I

-+-z

_I

ＰｴＺＺｷｩｩｩｩｩｩｩｩｩｩｬｩｩｩｩｬＰＬｯＡＡＰＡＡＡＡＲＡＡＰｾＮＰｾＰ

iiiiiiiiiij3000 ' . I ! SCALE- FEET I /

FIGURE

1

(6)

AIR TEMPERATURE

- ARl - - - DOT - ARl - - - DOT

100 e

₉₀

ｾ

₈₀

ｾ

>-I -

₇₀

0 ｾ

60

:::>" :::I: UJ

50 >

I -

40 «

- I UJ

30

0:::

20

10

90

u. 0

80 .

UJ 0:::

70

:::> I

-«

60

0::: UJ a.. ｾ

40

UJ I -0:::

30 «

20

10

20

30

10

20

30

\ ' - - - - ｶｾＭＭＭＭＭＭＭｊｉ｜ＧＭＭＭＭＭｾｶｾＭＭＭＭＭＭＭＭＧｉ

MAY 1968

JUNE 1968

FIGURE

2 DAILY AVERAGE RELATIVE HUMIDITY AND AIR TEMPERATURE

AT DOT WEATHER STATION AND ARL ( MAY - JUNE 1968 )

(7)

o

100 Z ::::>

0

₉₀

_{A Rl}

a..

"'"

_VI

- - - - DOT

Z ₈₀

-<

0:::

C>

₇₀ I -60 Z w I -Z _5-0

0 u

e

w 40 0::: ::::> I -30 VI

0

ｾ 20 0:::

<

1 0 10 20 30 10 20 30 " ' - - - -...ｶｾＭＭＭＭＭＭＭＭＮＮＮｊｉＢＧＭＭＭＭＭＭＭＭＭＭＭＧ｜ｶｾＭＭＭＭＭＭＧｉ

MAY

1968

_JUNE

₁₉₆₈

FIGURE

3 DAilY AVERAGE AIR MOISTURE CONTENT AT

DOT WEATHER

STATION AND AT ARl ( MAY-JUNE

1968)

(8)

100

•

90

80

ｾ

70 -

>I -o

60 ｾ

50

:::J

:c

l.LI

40 >

ｾ

30

...J l.LI ｾ

20 RELATIVE HUMI DITY

- A R l - - - - DOT

10

20

30

10

20

30

80 AIR TEMPERATURE

27 «

u o

5

22

15

10 -2

10

20

- - ARl - - - - DOT

- 7. 5

30

10

20

30 ''---,v,---..--J

1

_{'I.---;v,---J}

1

AUGUST 1969

SEPTEMBER 1969

-LJ.J ｾ

60

:::J I

-«

50

ｾ LJ.J a..

40

ｾ LJ.J I -ｾ

30 «

20 ::- 70

FIGURE

4 DAILY AVERAGE RELATIVE HUMIDITY AND AIR TEMPERATURE

AT DOT WEATHER STATION AND PRL ( AUGUST - SEPTEMBER

1969)

(9)

10 20 30 10 20 30 Ｇ｜ＭＭＭＭＭＭｾｶｾＭＭＭＭＭＭｊｉＧＧＭＭＭＭＭＭｾｶｾＭＭＭＭＭＭＭＭＭＭＧＧ AUGUST 1969 SEPTEMBER 1969 I 100

,

\

,

I In

\

_I Z 90 ｾ

,

0 ,

I, 0- ₈₀ _I' I

,

_{I 1} "-.

,

I _I _{I ,} In _I

,

I , Z I _I 1/ I , 70 I

r

<{

,

r

"

I , a.:: I

r

I () I \ I I 60 _I 1,

I

_I

,

' I

ｾｉ

_I l - _{I /} I Z I , :,;-50 ", w ",... /

....

I -/ Z /

0

40

,

u

-'

w a.:: ₃₀ ｾ I -In

0

20 AR l ｾ

----

DOT a.:: 1 0 <{ FIGURE 5

DAILY AVERAGE AIR MOISTURE CONTENT AT DOT WEATHER