CHEMICAL COMPOSITION OF FRESH SNOW IN HIMALAYAS AND KARAKORUM

1. CHEMICAL COMPOSITION OF FRESH SNOW IN HIMALAYAS AND KARAKORUM S. Polesello, M. Comi, A. Marinoni, M. Pecci, G. Tartari,S. Valsecchi and E. Vuillermoz “That pure congealed white, high Taurus snow, fanne’d with the eastern wind,...” Shakespeare, A Midsummer Night Dream

2. Why should we study fresh snow? • To characterise atmospheric depositions and estimate chemical loads in high altitude areas • To understand the sources of contaminants on local and regional scale • To give information on atmospheric pollution (can it act as “passive sampler”?) • To interpret glaciochemical records in ice core

3. Scientific development of snow studies in Central Asia high altitude sites • ’80 – Characterisation of the spatial and temporal distribution of snow chemistry in Central Asia • ’90 – how far does snow chemistry represent atmospheric chemistry? • Last decade – Ice coring for past atmosphere reconstruction

4. Activities of Water Research Institute (IRSA-CNR) • CHARACTERIZATION OF MONSOONIC DEPOSITION AT PYRAMID SITE • 1990-1992, summer– Intensive sampling of wet and dry deposition [Valsecchi et al., Sci. Total Environ., 226 (1999) 187] • 1998, September– Extensive fresh snow sampling in Khumbu valley [Marinoni et al. Atmos. Environ., 35 (2001) 3183] • SAMPLING OF SNOW DURING CLIMBING EXPEDITIONS • 1992, September – EVEREST (Southern slope) [Valsecchi et. al., 1999] • 1998, May – ISLAND PEAK (Southern slope) [Marinoni et al. 2001] • 2000, September – CHO OYU (Northern slope) [Balerna et al. Atmos. Environ., 37 (2003) 1573] • 2000, October– PUMORI (Southern slope) [unpublished results] • 2004: K2-2004 50 YEARS LATER PROJECT [unpublished results] • April-May– EVEREST (Northern slope) • June-July– K2 (Southern slope) • June-July– K2 (Northern slope) • 2005, May– ANNAPURNA [work in progress]

5. C H I N A P A K I S T A N NE P A L INDIA EVEREST ANNAPURNA CHO OYU K2 Determination of ion composition, nutrients, light carboxylic acids, trace metals, persistent organic pollutants, in situ radioactivity in the sub-surfacial snow layer

6. Collection of fresh snow samples at different altitudes by trained climbers Field determination of pH and conductivity Storage in special freezer to keep the snow frozen during the transport to Italy SAMPLING

7. Analytical methods • ION CHROMATOGRAPHY (with preconcentration or large volume injection): • Ionic macrocostituents: Cl-, NO3-, SO42-, NH4+, Na+, K+, Mg2+, Ca2+ • Carboxylic acids (oxalate, acetate, formate, metansulphonate, etc..) • SPECTROPHOTOMETRY: • Nutrients: Total Nitrogen (TN), Total Phosphorus (TP) • pH • Conductivity

8. Snow sampling in Khumbu valley PUMORI EVEREST Ev-K2-CNR PYRAMID ISLAND PEAK

9. Characterization of air mass sources in Khumbu valley by Principal Component Analysis Extra-monsoon samples Monsoon samples 2° Component: Marine source 1° Component: Continental source

10. COMPARISON BETWEEN MEAN VALUES OF EVEREST REGION, DURING MONSOON AND EXTRA-MONSOON SEASON, ALPS AND INTERNAL ANTARTICA µeq/L Data sources:Alps: Nikus et al., 1997; our unpublished results Himalaya : Marinoni et al., 2001; Balerna et al., 2003; Kang et al., 2004 Antartic Region: Whitlow et al., 1992; Legrand,1987.

11. CHEMICAL COMPOSITION OF FRESH SNOW SAMPLES FROM NORTHERN AND SOUTHERN SLOPES OF HIMALAYA DURING SUMMER MONSOON SEASON Data sources: Valsecchi et al., 1999; Shresta et al., 1997;Marinoni et al., 2001; Balerna et al., 2003

12. CHEMICAL COMPOSITION OF FRESH SNOW SAMPLES FROM NORTHERN AND SOUTHERN SLOPES OF HIMALAYA DURING EXTRAMONSOON SEASON Data sources: Jenkins et al., 1983; Marinoni et al., 2001; Balerna et al., 2003

13. COMPARISON BETWEEN EVEREST 2004 CAMPAIGN AND PREVIOUS CAMPAIGNS IN THE SAME AREA DURING EXTRA-MONSOON SEASON µeq/L Data sources: Jenkins et al., 1983; Marinoni et al., 2001; Balerna et al., 2003

14. K2-2004 50 YEARS LATER PROJECT: K2RESULTS 43 µeq/L

15. Sampling during climbing expeditions Concentrations vs Altitude: Is there a relationship?

16. K2-2004 50 YEARS LATER PROJECT: RESULTS TOTAL PHOSPHORUS (TP)

17. PUMORI 11-17 October 2000:7 sites from 5800 to 7160 m a.s.l. Correlation matrix

18. ? EVEREST 27 April- 18 May 2004:6 sites from 5200 to 7300 m a.s.l. Correlation matrix

19. Carboxylic acids Data source for ice cores: Lee et al., 2002; Lee et al., 2001; Kang et al., 2001

20. MAIN FEATURES OF HIMALAYAN FRESH SNOW CHEMICAL COMPOSITION • Samples can be classified in two main classes: summer monsoon and extra-monsoon samples • In the Everest region, concentrations on both slopes (Northern and Southern) are very similar in both periods • Monsoon depositions in central Himalayas are not substantially influenced by anthropogenic inputs (NO3 ~ 0.1-2.0 µeq/l ; SO4 ~ 0.05-2.0 µeq/l) • In extra-monsoon period high concentrations of crustal ions, sulphate and nitrate are measured • The concentration alternances is confirmed in ice core records and can be used for dating

21. Open issues: • Source of sulphate particularly in extra-monsoon period • Origin of crustal particles in extra-monsoon period (Central Asia dust storm or westernly driven Saharian air masses?) • Formation mechanisms and sources of organic acids • Relantionship between snow chemistry and aerosol chemistry

22. FUTURE AIMS Integration of deposition chemistry with aerosol chemistry in order to obtain complementary information on atmospheric processes involved in Atmospheric Brown Cloud Sulphate: 32% Organics: 26%

23. Thankyou! “et eunt homines admirari alta montium et ingentis fructus maris et latissimos lapsus fluminum et ocean ambitum et giros siderum, et reliquunt se ipsos” “And men go about to wonder at the heights of the mountains, and the mighty waves of the sea, and the wide sweep of rivers, and the circuit of ocean, and the revolution of the stars, but they do not consider themselves” Augustinus, Confessiones