Analysis of snow cover characteristics at Aklavik and Resolute, Northwest Territories

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Analysis of snow cover characteristics at Aklavik and Resolute, Northwest Territories

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N A T I O N A L R E S E A R C H C O U N C I L CANADA D I V I S I O N O F B U I L D I N G R E S E A R C H AN A N A L Y S I S O F SNOW COVER C H A R A C T E H I S T I C S AT A K L A V I K AND R E S O L U T E , NORTHWEST r E R R I T O R I E S by

G.

P.

W i l l i a m s R e p o r t No. 9 1 of t h e D i v i s i o n o f B u i l d i n g Research O t t a w a August 1956

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PREFACE

T h i s r e p o r t a n a l y s e s t h e snow c o v e r c h a r a c t e r i s t i c s measured a t t h e two A r c t i c s t a t i o n s of R e s o l u t e and A k l a v i k from 1947 t o 1954 under t h e s p o n s o r s h i p of t h e A s s o c i a t e Committee on S o i l and Snow Mechanics of t h e N a t i o n a l R e s e a r c h C o u n c i l of

Canada, Frequency d i a g r a m s show c o n s i d e r a b l e d i f f e r e n c e between t h e snow p r o p e r t i e s a t t h e s e two s t a t i o n s . G r a p h i c a l c o m p a r i s o n s a r e m a d e t o show d e p t h - t i m e v a r i a t i o n of h a r d n e s s , d e n s i t y , and g r a i n s i z e , The c l o s e r e l a t i o n between snow d e n s i t y , h a r d n e s s , and t e m p e r a t u r e g r a d i e n t i s a l s o shown g r a p h i c a l l y .

The a u t h o r of t h i s r e p o r t , an A s s i s t a n t R e s e a r c h O f f i c e r

i n .

t h e Snow and I c e S e c t i o n , h a s u s e d some o f t h e r e s u l t s of t h e Snow Survey i n dFder t o make a d e t a i l e d a n a l y s i s of snow c o v e r c h a r a c t e r i s t i c s a t two n o r t h e r n s t a t i o n s . These were s e l e c t e d as examples and i n view of t h e s p e c i a l i n t e r e s t i n n o r t h e r n c l i m a t i c c o n d . i t i o n s i n Cana.da,

It i s hoped t h a t a l l who r e a d t h i s r e p o r t w i l l f e e l n o t o n l y f r e a , b u t t h a t t h e y a r e i n v i t e d , t o submit t o t h e D i v i s i o n a n y c o m m e n t s on t h e work h e r e i n d e s c r i b e d , p a r t i c u l a r l y s i n c e i t

i s i n e s s e n c e a p i l o t s t u d y i n a f i e l d o f r e s e a r c h which i s o n l y now b e i n g opened up,

Ottawa

August 1956

R o b e r t

F.

_{L e g g e t ,}

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AN ANALYSIS OF SNOW COVER CHARACTERISTICS AT

AKLAVIK AND RESOLUTE, NORlBWEST TERRITORIES

b y

G , P. W i l l i a m s

S i n c e J.947 r e g u l a r o b s e r v a t i o n s of t h e p h y s i c a l c h a r - a c t e r i s t i c s of t h e snow c o v e r have been t a k e n a t Aklavik, l o c a t e d on t h e Mackenzie R i v e r d e l t a and a t R e s o l u t e , C o r n w a l l i s I s l a n d , Northwest T e r r i t o r i g s . These o b s e r v a t i o n s were p a r t of a g e n e r a l

snow s u r v e y a c r o s s Canada s p o n s o r e d by t h e A s s o c i a t e Committee on S o i l and Snow Mechanics of t h e N a t i o n a l R e s e a r c h C o u n c i l of Canada, a n d c a r r i e d o u t t h r o u g h t h e c l o s e c o - o p e r a t i o n of t h e D i v i s i o n of B u i l d i n g R e s e a r c h , N a t i o n a l R e s e a r c h C o u n c i l , and t h e

M e t e o r o l o g i c a l D i v i s i o n of t h e Department of T r a n s p o r t .

The amount of snow c o v e r , d e p t h of snow, s h a p e and s i z e of c r y s t a l s , snow s u r f a c e c o q d i t i o n s , a l o n g w i t h e s s e n t i a l m e t e o r o l o g i c a l d a t a wene r e c o r d e d d a i l y by o b s e r v e r s of t h e M e t e o r o l o g i c a l D i v i s i o n . Measurements of snow d e n s i t y , h a r d - n e s s , t e m p e r a t u r e , c r y s t a l s i z e and shape were t a k e n bi-weekly i n d i f f e r e n t snow l a y e r s . The i n s t r w n e n t s u s e d t o measure t h e c h a r a c t e r i s t i c s of t h e snow have b e e n d e s c r i b e d p r e v i o u s l y by EClein e t a 1 ( I ) ,

P r e l i m i n a r y r e s u l t s from a l l s t a t i o n s were a n a l y s e d by P e a r c e and Gold ( 2 ) . S i n c e t h e i r r e p o r t , which i n c l u d e s d a t a from 1947 t o 1950, d a t a f o r f o u r a d d i t i o n a l y e a r s have been c o l - l e c t e d and t h e r e f o r e a more d e t a i l e d a n a l y s i s i s w a r r a n t e d , The p u r p o s e of t h i s p r e s e n t a n a l y s i s i s t o show t h e v a r i a t i o n o f

snow c o v e r c h a r a c t e r i s t i c s a t t h e two A r c t i c s t a t i o n s o f R e s o l u t e and A k l a v i k from 1947 t o 1954. These two s t a t i o n s were c h o s e n f o r s t u d y b e c a u s e d a t a were q u i t e complete and p r e l i m i n a r y ana- l y s e s showed marked d i f f e r e n c e i n snow c h a r a c t e r i s t i c s measured a t t h e two s i t e s , COMPARISON OF SITES A k l a v i k i s l o c a t e d a t l a t i t u d e

6 8 O

14'

N. and l o n g i t u d e

1 3 4 O

507

W e a b o u t 50 m i l e s i n l a n d f r o m t h e A r c t i c Ocean, R e s o l u t e i s l o c a t e d a t l a t i t u d e 74O 3 0 ' N o and l o n g i t u d e 9 s 0 4 0 ' W. on C o r n w a l l i s I s l a n d . F i g u r e 1 i s a map of t h e Canadian A r c t i c showing t h e l o c a t i o n of t h e s e two s t a t i o n s . E l e v a t i o n o f t h e o b s e r v a t i o n s i t e a t Aklavik i s 30 f e e t above mean s e a l e v e l , The s i t e i s somewhat s h e l t e r e d by t h e

s c r u b b r u s h found i n t h i s a r e a . The t e r r a i n t o t h e n o r t h o f R e s o l u t e r i s e s g e n t l y t o a h e i g h t of a b o u t 200 f e e t above mean

s e a l e v e l , one m i l e from t h e s t a t i o n , The t e s t a r e a a t R e s o l u t e was chosen i n a s e m i - s h e l t e r e d l o c a t i o n s i n c e c o m p l e t e l y exposed

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a r e a s a r e blown c l e a r o f snow,

A s A k l a v i k i s a p p r o x i m a t e l y 400 m i l e s s o u t h and 1 , 0 0 0 m i l e s w e s t of R e s o l u t e , t h e r e i s a c o n s i d e r a b l e d i f f e r e n c e i n c l i m a t e between t h e two s t a t i o n s . The a n n u a l t o t a l s n o w f a l l i s

4T01

i n c h e s a t A k l a v i k and 30.2 i n c h e s a t R e s o l u t e . The a n n u a l a v e r a g e of d a i l y mean t e m p e r a t u r e i s

1 6 ' ~ .

a t A k l a v i & and

3 ' ~ .

a t R e s o l u t e . These v a l u e s were o b t a i n e d f r o m Addendum t o Volume I, C l i m a t i c Summaries f o r S e l e c t e d S t a t i o n s i n Canada, Meteorolo- g i c a l D i v i s i o n , Department of T r a n s p o r t , T o r o n t o ,

1954,

and a r e b a s e d on 22 y e a r s of o b s e r v a t i o n a t A k l a v i k and

6

y e a r s of o b s e r - v a t i o n a t R e s o l u t e ,

From 1949 t o 1954 R e s o l u t e had an a v e r a g e of 1 6 , 3 d a y s p e r month when t h e wind v e l o c i t y exceeded 9 m.p.h, d u r i n g t h e w i n t e r months, D u r i n g t h e same p e r i o d A k l a v i k had a n a v e r a g e of

5,9

d a y s p e r month when t h e wind v e l o c i t y exceeded 9 m,p.h. A

wind v e l o c i t y of 9 m,p.h, was c h o s e n a s a c r i t i c a l v e l o c i t y be- cause'i'according t o D m i t r i e v a

( 3 )

i t i s t , h e wind v e l o c i t y a t which

snow b e g i n s t o blow,

ANALYSIS OF DAILY SNOW C OVER OBSERVATIONS

From 1947 t o 1954 t h e maximum snow d e p t h r e c o r d e d a t A k l a v i k was 16,O i n c h e s . F o r t h r e e c o n s e c u t i v e y e a r s , 1949 t o

1950,

1950 t o

1951,

1 9 5 1 t o 1957, A k l a v i k r e p o r t e d snow d e p t h s u n d e r

5

i n c h e s , The maximum d e 6 t h r e c o r d e d a t R e s o l u t e f r o m 1 9 4 7 t o 1954 was

28

i n c h e s , I n a r e a s s u b j e c t t o d r i f t i n g , snow d e p t h i s of v a l u e i n d e s c r i b i n g a p a r t i c u l a r s i t e b u t d o e s n o t g i v e a n y i n d i c a t i o n of c o m p a r a t i v e amounts o f s e a s o n a l s n o w f a l l , F i g u r e 2 shows f r e q u e n c y p o l y g o n s f o r snow s u r f a c e c r y s t a l s h a p e , s i z e , and s u r f a c e c o n d i t i o n s , r e c o r d e d f r o m October 1 9 5 1 t o December 1954. A d e t a i l e d e x p l a n a t i o n of t h e symbols u s e d i s g i v e n by K l e i n e t a l f ( 1 ) . A k l a v i k shows a much g r e a t e r v a r i a t i o n i n s u r f a c e c r y s t a l s h a p e s , Depth h o a r o r t y p e 'e" was r e p o r t e d 32 _{p e r}

c'ent of t h e t i m e a t A k l a v i k and

1,s

p e r c e n t of t h e t i m e a t R e s o l u t e , A t R e s o l u t e t y p e "d" was r e p o r t e d

65

p e r c e n t of

t h e t i m e ,

The s u r f a c e g r a i n s i z e s r e c o r d e d a t R e s o l u t e were c o n s i s t e n t l y s m a l l e r t h a n a t A k l a v i k e v e n t h o u g h t h e g e n e r a l shape o f t h e f r e q u e n c y c u r v e i s t h e same, The l a r g e number of s u r f a c e h o a r o b s e r v a t i o n s i s one e x p l a n a t i o n f o r t h e l a r - g e r g r a i n s i z e s a t A k l a v i k , The s h a p e of t h e f r e q u e n c y c u r v e f o r s u r f a c e snow c o n d i t i o n s i s t h e same

'f'.m

b o t h s t a t i o n s , w i t h wind e r o s i o n b e i n g r e p o r t e d t w i c e a s o f t e n a t R e s o l u t e , and a smooth s u r - f a c e b e i n g r e p o r t e d t w i c e a s o f t e n a t A k l a v i k ,

(6)

FREQUENCY DIAGRAMS FOR BIdWEEKLY SNOW PROFILE OBSERVATIONS F i g u r e

3

shows f r e q u e n c y p o l y g o n s f o r snow c r y s t a l s i z e , d e n s i t y , and h a r d n e s s a t A k l a v i k and R e s o l u t e f r o m 1 9 4 7 t o 1954. O b s e r v a t i o n s were t a k e n b i - w e e k l y a t d i f f e r e n t l a y e r i n t e r v a l s f r o m t h e snow s u r f a c e t o t h e ground, A t R e s o l u t e

88

p e r c e n t o f t h e g r a i n - s i z e o b s e r v a t i o n s were u n d e r

1,s

rnm. A t A k l a v i k t h e g r a i n - s i z e v a r i a t i o n was much l a r g e r , The s h a p e o f t h e f r e q u e n c y d i a g r a m f o r snow d e n s i t y was q u i t e s i m i l a r a t b o t h s t a t i o n s , w i t h a mean d e n s i t y o f 0,242 a t A k l a v i k , and a mean d e n s i t y o f 0.356 a t R e s o l u t e , A k l a v i k h a r d - n e s s v a l u e s were s m a l l e r and t h e v a r i a t i o n i n h a r d n e s s was l e s s t h a n a t R e s o l u t e ,

DEPTH-TIME V A R I A T I O N OF SNOW PROFILE PROPERTIES

-

Even u n d e r s i m i l a r s i t e c o n d i t i o n s snow p r o p e r t i e s measured i n one p l a c e w i l l n o t be t h e s p e a s p r o p e r t i e s meas- u r e d i n a n o t h e r p l a q e a few y a r d s away. F o r t h a t r e a s o n any c o m p a r i s o n between c h a r a c t e r i s t i c s o f snow a t s t a t i o n s s e v e r a l h u n d r e d m i l e s a p a r t must b e on a. b r o a d b a s i s , F i g u r e

4,

showing t h e a v e r a g e v a r i a t i o n of snow h a r d - n e s s , d e n s i t y , and g r a i n s i z e w i t h d e p t h , i s a g r a p h i c a l compar- i s o n of o v e r - a l l snow p r o p e r t i e s f r o m 1947 t o 1954, A t A k l a v i k snow h a r d n e s s g e n e r a l l y i n c r e a s e s w i t h d e p t h . A t R e s o l u t e t h e r e i s a s h a r p d e c r e a s e i n h a r d n e s s down t o

8

i n c h e s , and a t g r e a t e r d e p t h s t h e h a r d n e s s i s e s s e n t i a l l y c o n s t a n t . A t b o t h s t a t i o n s t h e a v e r a g e d e n s i t y ' r e m h i n s e s s e n t i a l l y c o n s t a n t w i t h d e p t h , The a v e r a g e g r a i n s i z e i n c r e a s e s w i t h d e p t h a t A k l a v i k and r e m a i n s e s s e n t i a l l y c o n s t a n t w i t h d e p t h a t R e s o l u t e , F i g u r e

5

shows t h e v a r i a t i o n of a v e r a g e m o n t h l y snow h a r d n e s s , d e n s i t y , and g r a i n s i z e , and i s a n o t h e r g r a p h i c a l com- p a r i s o n of snow p r o p e r t i e s on a b r o a d b a s i s . The g r a i n s i z e

shows a marked i n c r e a s e w i t h t i m e a t A k l a v i k and i s a l m o s t con- s t a n t w i t h r e s p e c t t o t i m e a t R e s o l u t e , The d e n s i t y v a r i a t i o n w i t h t i m e i s v e r y s i m i l a r Tor b o t h s t a t i o n s . The a v e r a g e h a r d -

n e s s a t R e s o l u t e i n c r e a s e s t o a maximum of n e a r l y 2500 gm/cm? i n March, The i n c r e a s e i n a v e r a g e h a r d n e s s f o r A k l a v i k i s much l e s s , r e a c h i n g a maximum of 700 em/cmo2 i n F e b r u a r y , F i g u r e 6 combines t h e d a t a u s e d t o o b t a i n F i g s .

4

a n d

5

t o i n d i c a t e o v e r - a l l d e p t h - t i m e v a r i a t i o n s , F i g u r e

6

shows t h a t t h e snow c r y s t a l s a t A k l a v i k i n c r e a s e m a r k e d l y i n s i z e w i t h r e s p e c t t o t i m e and d e p t h , u n d e r g o i n g t h e metamorphism r e p o r t e d b y R i c h t e r

(4),

A t R e s o l u t e t h e r e i s a d e f i n i t e t e n d e n c y f o r g r a i n s i z e t o r e m a i n c o n s t a n t w i t h r e s p e c t t o t i m e and d e p t h , Average d e n s i t y i n c r e a s e s g r a d u a l l y w i t h t i m e , and r e m a i n s e s s e n t i a l l y c o n s t a n t w i t h d e p t h a t b o t h s t a t i o n s , B o t h s t a t i o n s show a n i n c r e a s e i n h a r d n e s s w i t h t i m e up t o a maximum i n

F e b r u a r y and March, and t h e n d e c r e a s i n g h a r d n e s s i s e v i d e n t a t b o t h s t a t i o n s i n A p r i l and May,

(7)

RELATION BETWEEN DENSITY-HARDNESS AND TEMPERATURE GRADIENT F i g u r e 7 a shows a v e r a g e m o n t h l y l o g o f h a r d n e s s p l o t t e d a g a i n s t a v e r a g e m o n t h l y d e n s l t y f o r b o t h s t a t i o n s . T h e r e i s a c l o s e r e l a t i o n s h i p b e t w e e n t h e s e two p r o p e r t i e s a s r e p o r t e d b y Gold

( 5 ) ,

C l o s e l y r e l a t e d t o d e n s i t y and h a r d n e s s i s tempera- t u r e g r a d i e n t . F i g u r e 7b shows a v e r a g e m o n t h l y t e m p e r a t u r e p a d i e n t p l o t t e d a g a i n s t a v e r a g e m o n t h l y d e n s i t y from November t o March. D u r i n g t h i s p e r i o d of c o n t i n u o u s c o l d t h e d i f f e r e n c e i n i n s u l a t i n g v a l u e o f snow c o v e r a t t h e s e two s t a t i o n s was q u i t e marked, S e v e r a l t i m e s a t A k l a v i k t h e s u r f a c e snow t e m p e r a t u r e was r e p o r t e d a t l e a s t 2 0 ' ~ ~ c o l d e r t h a n a t a 1 2 - i n c h d e p t h . A t R e s o l u t e t h e r e p o r t e d s u r f a c e snow t e m p e r a t u r e was s e l d o m 1 0 ' ~ . c o l d e r t h a n a t t h e 1 2 - i n c h d e p t h . T h i s d i f f e r e n c e i n i n s u l a t i n g v a l u e i s c l o s e l y r e l a t e d t o t h e d i f f e r e n c e i n d e n s i t y , c o n f i r m i n g s t u d i e s of K o n d r a t a e v a

( 6 ) .

D I SC[J SSION OF RESULTS The f r e q u e n c y d i a g r a n s on F i g .

3

e m p h a s i z e t h e d i f f e r e n c e i n snow p r o p e r t i e s a t t h e s e two s t a t i o n s , Even t h o u g h no p r o o f i s a t t e m p t e d i n t h i s r e p o r t , much of t h i s d i f f e r e n c e must b e a t t r i - b u t e d t o c l i m a t i c f a c t o r s . F o r e x a m p l e , o b s e r v e r s a t R e s o l u t e h a v e n o t e d t h a t a f t e r a s e v e r e s t o r m t h e snow was p a c k e d s o h a r d t h a t t r u c k s c o u l d b e d r i v e n o v e r t h e s n o w , d r i f t s

( 7 ) .

T h i s o b s e r - v a t i o n s u g g e s t s t h a t wind i s one f a c t o r w h i c h m i g h t e x p l a i n t h e l a r g e d i f f e r e n c e s i n snow h a r d n e s s b e t w e e n t h e s e two s t a t i o n s . The r e l a t i o n b e t w e e n snow c h a r a c t e r i s t i c s s u c h a s g r a i n s i z e , d e n s i t y , a n d h a r d n e s s a r e complex, i n v o l v i n g many d i v e r s e f a c t o r s . The g r a p h i c a l c o m p a r i s o n s o f snow p r o p e r t i e s on a b r o a d b a s i s e n a b l e some g e n e r a l c o m p a r i s o n s t o b e made, F o r example, t h e v a r i a t i o n of a v e r a g e g r a i n s i z e w i t h t i m e a n d d e p t h shown i n F i g s ,

4

and

5,

i s d i f f e r e n t t o t h e t i m e - d e p t h v a r i a t i o n o f d e n s i t y and h a r d n e s s , I f p a i n s i z e ,

as

m e a s u r e d by t h e o b s e r v e r s , were c l o s e l y r e l a t e d t o h a r d n e s s o r d e n s i t y , t h e g e n e r a l t i m e - d e p t h p a t t e r n s h o u l d show more s i m i l a r i t y , F i g u r e 7 shows t h a t a c l o s e r e l a t i o n e x i s t s b e t w e e n snow d e n s i t y , l o g of h a r d n e s s , and t e m p e r a t u r e g r a d i e n t . I t was d i f f i c u l t t o a n a l y s e t h i s r e l a t i o n s h i p i n d e t a i l b e c a u s e t e m p e r - a t u r e g r a d i e n t f l u c t u a t e s w i t h d a i l y a i r t e m p e r a t u r e c h a n g e s w h e r e a s c h a n g e s i n d e n s i t y and h a r d n e s s a r e g r a d u a l . F o r example, i n March a t b o t h s t a t i o n s , t h e t e m p e r a t u r e g r a d i e n t u s u a l l y r e v e r - s e s a n d snow t e m p e r a t u r e s s t a r t t o d e c r e a s e w i t h d e p t h , T h i s r e v e r s a l o f t e m p e r a t u r e g r a d i e n t o f t e n c o i n c i d e s w i t h a g r a d u a l d e c r e a s e i n h a r d n e s s a t b o t h s t a t i o n s . More d e t a i l e d s t u d i e s w i l l b e n e e d e d t o f i n d o u t w h e t h e r t h i s r e v e r s a l i n t e m p e r a t u r e g r a d i e n t c a n be r e l a t e d t o t h e g r a d u a l d e c r e a s e i n snow h a r d n e s s .

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ACKNOWLEDGMENTS

The a u t h o r w i s h e s t o acknowledge t h e work of t h e w e a t h e r o b s e r v e r s s t a t i o n e d a t A k l a v i k and R e s o l u t e f r o m 1947 t o 1954. Without t h e i r c o - o p e r a t i o n and e f f o r t , o f t e n u n d e r a d v e r s e w e a t h e r c o n d i t i o n s , i t would have been i m p o s s i b l e t o p r e p a r e t h i s r e p o r t ,

The a u t h o r a l s o w i s h e s t o e x p r e s s h i s a p p r e c i a t i o n t o L O W , Gold f o r g u i d a n c e i n p r e p a r i n g t h i s r e p o r t ,

REFERENCES

-

(1) K l e i n , G,J,, D.C, P e a r c e and LOWo Gold. Method of m e a s u r i n g t h e s i g n i f i c a n t c h a r a c t e r i s t i c s of a _snow-cover. _Nat- i o n a l R e s e a r c h C o u n c i l , A s s o c i a t e Committee on S o i l and Snow Mechanics, T e c h n i c a l Memorandum No, 1 8 , 59 p. 1950,

( 2 ) P e a r c e , D.C. and L.W. Gold, The Canadian snow s u r v e y 1947- 1 9 5 0 0 N a t i o n a l R e s e a r c h C o u n c i l , A s s o c i a t e Committee on S o i l and Snow Mochanics, T e c h n i c a l Memorandum No, 21,

39

Po 1951.

( 3 )

D m i t r i e v a , N.G, C a l c u l a t i o n of snow c o v e r d e n s i t y u s i n g m e t e o r o l o g i c a l d a t a , ( R a s c h e t p l o t n o s t i snozhnogo pokrova po r n e t e o r o l o g i s c h e s k i m dannym, M e t e o r o l o g i i a i G i d r o l o g l f a , No, 2, 1 9 5 0 ) . SIPRE T r a n s l a t i o n NO.

24,

4 P*

19540

( 4 )

R i c h t e r , G O D . Snow c o v e r , i t s f o r m a t i o n and p r o p e r t i e s . Academy of S c i e n c e , U. S,S.R., P o p u l a r S c i e n c e S e r i e s , 1 2 5 P O 19450

( 5 )

Gold, LOW. The s t r e n g t h o f snow i n compression. (To be p u b l i s h e d by t h e J o u r n a l of G l a c i o l o g y , 1956,) ,

( 6 )

Kondratseva, A , S , Thermal c o n d u c t i v i t y of t h e snow c o v e r and p h y s i c a l p r o c e s s e s c a u s e d by t h e t e m p e r a t u r e p a - d i e n t . ( T e p l o p r o v o d n o s t snegovogo pokrova i f i z i c h e s k i e p r o t s e s s y , p r o i s k h o d i a s c h i e v nem pod v l i a n i e m tempera- t u r n o g o gradients, P u b l i s h e d i n " P h y s i c a l and m e c h a n i c a l p r o p e r t i e s of snow and t h e i r u t i l i z a t i o n i n d r f i e l d and r o a d c o n s t r u c t i o n t ' . Moscow-Leningrad: Akademiia Nauk SSSR, p, 14-28, 1 9 4 5 ) . SIPRE T r a n s l a t i o n NO. 22,

13

p. 19540

( 7 )

Rae, RoT;l. A r c t i c e x p e r i e n c e s o r l i f e b e g i n s a t f o r t y belowe Royal M e t e o r o l o g i c a l S o c i e t y , Canadian Branch, Val. 1, No. 2, 1 2 p, 1950,

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AR CTIC OCEAN GREENLAND

F I G U R E I

S K E T C H

SHOWING

L O C A T I O N

O F AKLAVIK

R E S O L U T E

DBR, REPORT 91

(10)

W CLASS TYPE

s

i=

60 Q _{TO OROINAL FORM.}STARS OR PLATES CLOSE

k

o

b

NEEDLES OR COLUMNS

C- 4 0 CLOSE

r0

OR/G/NAL FORM.

Z

w

c

ROUNDED GRA/NS

W

0 2 0

a

SETTLED SNOW. W Q

d

S E r l L E D SNOW W / I H 0

a

b

c

d

e

CRYSTAL FACETS. DEPTH HOAR. CLASS INTERVAL

FIGURE

2 FREQUENCY POLYGONS FOR SNOW

SURFACE CRYSTAL S I Z E ,

SHAPE

AND

SURFACE AT AKLAVIK

8 _RESOLUTE.

(11)

CLASS INTERVAL ( m m )

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

L

DENSITY

1

FIGURE 3 FREQUENCY POLYGONS FOR SNOW CRYSTAL S l f E DENSITY, HARDNESS AT AKLAVlK

a

RESOLUTE. 1947-34.

(12)

FIGURE 4

VARIATION

OF AVERAGE SNOW HARDNESS, DENSITY

8 GRAIN SlZE WITH

D E P T H AT AKCAVIK

a

RESOLUTE

DBR.

REPORT 91

AVERAGE HARDNESS gm/cd

500 1000 1500 2000 2500

1 C K u v / K

i

AVERAGE GRAIN SIZE mm

1.0 2 . 0 3 . 0 4.0 5.0

I

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AVERAGE DENSITY gm/cm3

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(13)

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SIZE'

DEC FEB APR JUNE

* I 0

OCT 0 DEC FEB 9----. 0

,

.' *

- -

APR - JUNE 1 ,0@-

-

HARDNESS

500

OCT

'

/ / -0

DEC FEB APR JUNE

FIGURE

5 VARIATION

OF

AVERAGE

MONTHLY SNOW

p-

*-

-./#5*

A

KL

A

VIK

I

RESOLUTE7

HARDNESS,

DENSITY

8 _GRAIN

_SIZE

--a

DBR. REPORT 91

(14)

1

AKLAVIK,

i

201,,,

,,,

,F, APR

/"A

OCT OEC FEB APR JUHE

CRYSTAL

SIZE (mm)

DENSITY

( gm

/

c d )

AKLAVIK

1

20!!

I,,,.

;Ed ' A

jUN!

O C T D L C FEB APR JUNE

HARDNESS ( gm/cm?)

FIGURE 6 AVERAGE VARIATION OF CRYSTAL

SIZE, DENSITY, HARDNESS, WITH

DEPTH

a

TIME AT AKLAVIK

a

RESOLUTE. (1947- 64)

(15)

2 - 0

3 I

I-

tn

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w

I Z

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