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METEOROLOGY, CHEMISTRY, ACIDITY OF MOUNTAIN SNOWFALLS AND SNOWPACK
CHEMISTRY
Y. Page
To cite this version:
Y. Page. METEOROLOGY, CHEMISTRY, ACIDITY OF MOUNTAIN SNOWFALLS AND SNOWPACK CHEMISTRY. Journal de Physique Colloques, 1987, 48 (C1), pp.C1-613-C1-617.
�10.1051/jphyscol:1987184�. �jpa-00226449�
JOURNAL DE PHYSIQUE
Colloque C1, suppl6men-t au n o 3 , Tome 48, mars 1987
METEOROLOGY, CHEMISTRY, ACIDITY OF MOUNTAIN SNOWFALLS AND SNOWPACK CHEMISTRY
Y. PAGE
D6partement de GBographie, universit6 de Savoie, B.P. 1104, F-73011 Chambery Cedex, France
RESUME
Depuis 1 ' h i v e r 1982/83, on e t u d i e chaque semaine 1 'e v o l u t i o n chimique du manteau neigeux pendant l ' h i v e r ; depuis l ' a n n e e 1984/85, on Gtudie l e s p r e c i - p i t a t i o n s , e t en p a r t i c u l i e r l e s chutes de neige.
Les s i t e s e t l e s e n d r o j t s de pr616vements, oC l ' o n c o l l e c t e l e s 6 c h a n t i l l o n s , sont s i t u e s en France e t en Autriche.
On e f f e c t u e des p r o f i l s s t r a t i g r a p h i q u e s e t chimiques a i n s i que des observa- t i o n s nivo-met6orologiques pendant t o u t l ' h i v e r . L'analyse chimique donne pour l e s p r e c i p i t a t i o n s e t l e manteau neigeux l e s valeurs des i o n s : Na+, K+, Ca++, Mg++.
On essaie de comprendre l e s d i f f e r e n c e s q u i e x i s t e n t e n t r e chaque chute de neige e t l e s consequences de c e t t e v a r i a b i l i t e , a i n s i que l e r 8 l e chimique du manteau neigeux.
ABSTRACT
Since t h e w i n t e r 1982/83, we have been s t u d y i n g each week t h e chemistry o f t h e snowpack d u r i n g t h e w i n t e r ; since t h e year 1984/85, we a r e studying t h e pre- c i p i t a t i o n s and p a r t i c u l a r l y t h e s n o w f a l l s .
The areas and t h e t e s t - s i t e s , where snow sampfes have been c o l l e c t e d are i n France and A u s t r i a .
Standard snow and chemical p r o f i l e s were done, and meteorological i n f o r m a t i o n was a l s o c o l l e c t e d on a continuous basis d u r i n g t h e whole w i n t e r .
The chemical analyses g i v e i n f o r m a t i o n o f t h e content i n t h e p r e c i p i t a t i o n s and t h e snowpack o f t h e f o l l o w i n g i o n s : Na+, K+, Ca++, Mg++.
We t r y t o understand t h e d i f f e r e n c e s between each snowfall and t h e impacts from t h e v a r i a b i l i t y o f a c i d p r e c i p i t a t i o n s and t h e chemical r o l e o f t h e snow- pack.
INTRODUCTION
The study o f t h e s o l i d p r e c i p i t a t i o n s a t mid-and-high a l t l t u d e s permits t o know t h e importance o f t h e a c i d i t y and t h e impact on t h e envi'ronment. At t h e end o f t h e w i n t e r , t h e snowpack i s t h e chemical memory o f a l l meteorological events o f t h e w i n t e r .
Our purpose i s t o observe t h e chemistry o f some s n o w f a l l s a t d i f f e r e n t places i n Europe and t o show t h e i r c h a r a c t e r i s t i c s and their consequences on t h e snowpack.
Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1987184
JOURNAL DE PHYSIQUE
1. MATERIALS AND METHODS.
1.1. STUDY SITE -
The t e s t - s i t e s , where snow samples have been c o l l e c t e d d u r i n g t h e w i n t e r 1985/86, a r e i n ski-areas, two i n t h e French North-Alps, and two i n A u s t r i a :
. FRANCE : VALMOREL, 1400 M, N.W.
I n t h i s area, t h e r e a r e f o u r t e s t - s i t e s where we c o l l e c t e d snow samples ;
Area 1 - VALMOREL, 1400 M, N.W. ; Area 2 - GOLLET, 1850 M, S.E. ; Area 3 - PIERREFORT, 1850 M, N.W. ; Area 4 - COL DE LA MADELEINE, 2000 M,
360"
. AUSTRIA : SANKT ANTON, 1900 M OBERGURGL, 1938 M
I n t h e ski-areas and on t h e t e s t - s i t e s , we c o l l e c t e d nivo-meteorological i n f o r - mation each day d u r i n g t h e w i n t e r : wind d i r e c t i o n , p r e c i p i t a t i o n , a i r tempera- t u r e , new snow-depth, t o t a l snow-depth, surface snow temperature.
Standard snow p r o f i l e s were done each week a t t h e d i f f e r e n t areas and s i t e s where samples were c o l l e c t e d .
1.2. FIELD SAMPLING -
A l l t e s t - s i t e s , where t h e samples were been c o l l e c t e d , are s i t u a t e d f a r from t h e ski-areas t o avoid p o l l u t i o n .
For t h e chemical a n a l y s i s o f t h e snowfalls, we c o l l e c t e d snow samples i n polye- t h y l e n b o t t l e s , and f o r t h e snowpack we c o l l e c t e d snow samples i n t h e standard snow p r o f i l e s , p e r p e n d i c u l a r l y each 10 cm, w i t h p o l y e t h y l e n tubes. The b o t t l e s and t h e tubes were cleaned, and d u r i n g t h e sampling s p e c i a l care were p r o v i d e d t o avoid any p o l l u t i o n t h a t might a l t e r t h e chemical a n a l y s i s . A l l t h e samples were packed and forwarded i n a c o l d room i n t h e s k i r e s o r t s ( a t - 20°C), then i n CHAMBERY w a i t i n g t o be analysed.
1.3. ANALYTICAL TECHNIQUES -
The chemical analyses show us : t h e r e s i s t i v i t y ( c o n d u c t i m i t e r SCHOTT C.G.817), t h e P.H. (PH Meter SCHOTT C.G.857) and t h e i o n s K+, Na+, Ca++, Mg++ ( s p e c t r o -
photometer A.A. 1475 VARIAN). Here t o o we p r o v i d e special care d u r i n g t h e ana- l y s e s t o avoid p o l l u t i o n , and t h e leads were cleaned between each analysis.
2. RESULTS.
2.1. THE CHEMISTRY OF SOME SNOWFALLS I N VALMOREL -
We have choosen some p r e c i p i t a t i o n s events, and we see f i r s t o f a l l t h a t t h e P.H.
has a value between 8,4 and 4. We n o t i c e a v a r i a t i o n o f i o n s f o r each snowfall.
The a n a l y s i s shows a r e l a t i v e importance o f Ca++.
Table I. The chemistry o f s n o w f a l l s i n VALMOREL :
2.2. THE CHEMISTRY OF SOME SNOWFALLS I N VALMEINIER -
Table 11. The chemistry o f some s n o w f a l l s i n VALMEINIER :
Area
1T e s t - S i t e A4 A4 A 1 A4 A4 A3 A3 A2 A2 Snowf a1 1
P e r t u r b a t i o n G.deGCnes
W.
W.
N.W.
N.W.
W.
S.W.
N.W.
S.W.
Area/Data 06.01.86 11.01.86 12.01.86 13.01.86 15.01.86 19.01.86 17.02.86 29.03.86 05.04.86
We see t h e same v a r i a t i o n s f o r t h e P.H. (8,20 - 4,301 and t h e i o n s ( t h e v a l u e o f Ca+J i s t h e most i m p o r t a n t ) .
2.3. COMPARISON BETWEEN THE TWO AREAS -
Table I I I. Comparison o f snowfall s d u r i n g t h e same p r e c i p i t a t i o n : Concentration (PPM)
Snowf a1 1 P e r t u r b a t i o n
W.
N.W.
W.N.W.
N.W.
N.W.
N.W.
N.W.
W.
Area/Data 08.01.86 13.01.86 14.01.86 15.01.86 16.01.86 23.01.86 31.01.86 13.03.86
Concentration (PPM)
Area VALMOREL VALMEINIER VALMOREL VALMEINIER Mg++
0,34 0,12 0,12 0,02 0,09 0,OO 0,06 0,04 0,45 K+
0,12 0,23 0,19 0,03 0,05 0,OO 0,02 0,04 0,13
P.H.
8,10 8,40 6,Ol 5,14 6,50 4,45 4,73 4,16 6,90
Snowf a1 1 P e r t u r b a t i o n
N.W.
N.W.
N.W.
N.W.
r
Area/Data 13.01.86 13.01.86 15.01.86 15.01.86
Ca++
5,85 2,50 1,77 0,22 0,17 0,03 0,22 0,23 3,37 Na+
0,31 0,22 0,17 0,09 0,38 0,OO 0,02 0,06 0,09
P.H.
6,62 6,38 8,20 4,46 4,43 5,27 4,84 4,32
Na+
0,08 0,03 0,07 0,31 1,14 0,OO 0,12 0,OO
Concentration (PPM)
Ca++
3,OO 1,92 2,90 0,31 0,42 0,03 0,22 0,06 K+
0,lO 0,03 0,03 0,03 0,54 0,Ol 0,12 0,Ol
Mg++
0,lO 0,07 0,06 0,07 0,08 0,OO 0,04 0,Ol
P.H.
5,14 6,38 6,50 4,46
Mg++
0,02 0,07 0,09 0,07 Na+
0,09 0,03 0,38 0,31
Ca++
0,22 1,92 0,17 0,31 K+
0,03
0,03
0,05
0,03
CI-616 JOURNAL DE PHYSIQUE
The two areas are s i t u a t e d a t 25 k i l o m e t e r s from each o t h e r as t h e crew f l i e s . The r e s u l t s show t h a t , f o r t h e same p e r t u r b a t i o n , t h e c o n c e n t r a t i o n o f i o n s and t h e a c i d i t y change.
We c o l l e c t e d t h e snow d u r i n g t h e snowfall
:these r e s u l t s suggest t h a t d u r i n g t h e moving o f t h e p e r t u r b a t i o n , t h e snow l o s e s o r gains a c i d i t y and ions.
2.4. COMPARISON BETWEEN THE AREAS I N FRANCE AND I N AUSTRIA -
Table I V . Snowfalls i n France and i n A u s t r i a :
We t r y t o know i f t h e d i s t a n c e (more than 100 k i l o m e t e r s ) , f o r t h e same per- t u r b a t i o n , has an i n f l u e n c e on a c i d i t y . The conclusions are t h e same as before, except f o r t h e 19.01.86 where t h e v a r i a b i l i t y o f t h e P.H. and i o n s i s very low.
19.01.86
3. ACIDITY OF MOUNTAIN SNOWFALLS AND SNOWPACK CHEMISTRY.
The snowpack chemistry depends on each snowfall, b u t i t i s a f f e c t e d by t h e d r y d e p o s i t i o n and t h e meteorological e v o l u t i o n .
The e v o l u t i o n o f t h e seasonal snowpack depends on t h e depth and t h e s t r u c t u r e o f it.
During t h e w i n t e r 1984/85, we analyzed 28 snowpacks and temporarly we conclu- ded, t h a t a f t e r t h e snowfall, t h e snowpack i s a s o r t o f chemical f i l t e r (impor- tance o f each snowlayer and i c e l a y e r ) , and d u r i n g t h e snowmelt t h e snowpack discharges t h e i o n s i n t o t h e nature.
We can sum up t h e e v o l u t i o n o f t h e chemistry i n t h e snowpack i n a f i g u r e . 4,46
4,76 4,74
Atmosphere
P r e c i p i t a t i o n s (snow+rai n ) Dry d e p o s i t i o n
J.
C
Surf ace
0,OO 0,04 0,08
Snowpack = F i l t e r
Soi 1 Heat +
T Ions t r a n s f e r
F i g . 1. Schema o f t h e e v o l u t i o n o f t h e chemistry i n t h e snowpack 0,OO
0,03 0,08
0,OO 0,Ol 0,Ol
0,03 0,03 0,05
W.
W.
W.
VALMOREL
ST .ANTON
OBERGURGL
4. DISCUSSION.
I f we consider t h e purpose o f t h i s study, we conclude t h a t t h e chemistry o f t h e s n o w f a l l s i s very i r r e g u l a r , and t h e source o f contaminants c o u l d be t h e i n d u s t r i e s o f t h e v a l l e y s . This v a r i a b i l i t y o f a c i d i t y has an impact i n moun- t a i n d u r i n g t h e w i n t e r and t h e snowmelt.
The e v o l u t i o n o f t h e snowpack chemistry depends on t h e general and t h e l o c a l meteorology.
CONCLUSION.
The problem o f t h e chemistry o f s n o w f a l l s and t h e snowpack a r e l i n k e d each o t h e r ; t h e number o f parameters i s important, and each o f them must be s t u d i e d alone i n r e l a t i o n s h i p w i t h t h e others.
ACKNOWLEDGMENTS.
I thank t h e s k i - p a t r o l e r s o f VALMOREL and p a r t i c u l a r l y S. GROGNIET ; t h e D i r e c t o r o f SANKT-ANTON (S. M.HANDLER AND HOLZKNECHT) ; Miss V .THOMASSET and S. G.GANIERE ; Dr GABL (WETTERDIENSTELLE INNSBRUCK, and DBERGURGL) ,
who c o l l e c t e d t h e snow samples.
I thank t h e Biopedology Department o f t h e U n i v e r s i t y o f Savoie (Dr GENSAC, L.TROSSET, Mrs VINEL) f o r t h e a i d i n t h e analysis.
I
