Introduction
Sample collection and analysis
Time | Cl−
| NO2
−
| NO3
−
| SO4
2−
| Na+
| NH4
+
| K+
| Mg2+
| Ca2+
| Precipitation | Temperature | Σcat/Σan |
---|---|---|---|---|---|---|---|---|---|---|---|---|
2008-11-18 | 0.9 | 0.0 | 1.9 | 7.6 | 0.8 | 0.2 | 0.6 | 0.2 | 12.9 | 24.1 | −4.0 | 1.4 |
2008-12-15 | 1.5 | 0.1 | 10.3 | 31.0 | 0.4 | 0.4 | 0.7 | 11.0 | 624.2 | 8.5 | −5.4 | 14.9 |
2009-01-20 | 2.1 | 0.0 | 16.8 | 24.8 | 0.6 | 0.0 | 0.9 | 11.4 | 1,007.3 | 4.5 | −7.4 | 23.3 |
2009-02-18 | 1.0 | 0.1 | 4.8 | 19.6 | 0.4 | 0.3 | 0.5 | 3.9 | 217.3 | 5.6 | −6.6 | 8.7 |
2009-03-16 | 0.9 | 0.1 | 3.7 | 16.7 | 0.3 | 0.3 | 0.4 | 2.7 | 149.6 | 22.7 | −6.1 | 7.2 |
2009-04-20 | 4.6 | 0.1 | 42.1 | 270.8 | 1.6 | 7.4 | 4.2 | 3.7 | 117.3 | 35.6 | −1.8 | 0.4 |
2009-05-18 | 3.1 | 0.1 | 6.7 | 26.3 | 1.8 | 0.8 | 1.6 | 2.2 | 37.8 | 128.5 | 1.6 | 1.2 |
2009-06-18 | 0.6 | 0.1 | 1.8 | 14.0 | 0.0 | 0.2 | 0.3 | 0.4 | 14.4 | 408.2 | 3.8 | 0.9 |
2009-07-18 | 0.4 | 0.1 | 1.6 | 12.0 | 0.1 | 0.0 | 0.3 | 2.2 | 44.0 | 452.7 | 5.2 | 3.3 |
2009-08-19 | 0.4 | 0.0 | 5.8 | 13.8 | 0.0 | 0.1 | 0.2 | 1.2 | 13.7 | 388.1 | 4.3 | 0.8 |
2009-09-20 | 0.5 | 0.0 | 4.6 | 26.2 | 0.0 | 0.6 | 0.5 | 2.8 | 41.7 | 178.3 | 3.4 | 1.5 |
2009-10-20 | 1.1 | 0.1 | 22.3 | 84.9 | 0.0 | 0.8 | 0.9 | 18.4 | 493.3 | 133.7 | 0.9 | 4.7 |
Dry season | 1.8 | 0.1 | 13.3 | 61.7 | 0.7 | 1.4 | 1.2 | 5.5 | 354.8 | 16.8 | −5.2 | 9.3 |
Rainy season | 1.0 | 0.1 | 7.1 | 29.5 | 0.3 | 0.4 | 0.6 | 4.5 | 107.5 | 281.6 | 3.2 | 2.1 |
Annual | 1.4 | 0.1 | 10.2 | 45.6 | 0.5 | 0.9 | 0.9 | 5.0 | 231.1 | 149.2 | −1.3 | 5.7 |
Trajectory analyses and sea-salt tracer
Results
pH and conductivity
Major ions and ion balance
Seasonal variation of major ions
Discussion
Ion correlation and different sources in the fresh snow
Cl−
| NO2
−
| NO3
−
| SO4
2−
| Na+
| NH4
+
| K+
| Mg2+
| Ca2+
| Pre | Wind | |
---|---|---|---|---|---|---|---|---|---|---|---|
Cl−
| 1 | ||||||||||
NO2
−
| 0.180 | 1 | |||||||||
NO3
−
| 0.998** | 0.200 | 1 | ||||||||
SO4
2−
| 0.960** | 0.344 | 0.951** | 1 | |||||||
Na+
| 0.893* | −0.027 | 0.867* | 0.912* | 1 | ||||||
NH4
+
| 0.936** | 0.353 | 0.924** | 0.997** | 0.918** | 1 | |||||
K+
| 0.974** | 0.246 | 0.964** | 0.995** | 0.942** | 0.989** | 1 | ||||
Mg2+
| 0.110 | −0.053 | 0.152 | −0.119 | −0.250 | −0.198 | −0.099 | 1 | |||
Ca2+
| 0.019 | −0.314 | 0.058 | −0.247 | −0.293 | −0.325 | −0.205 | 0.946** | 1 | ||
Precipitation | 0.539 | 0.156 | 0.504 | 0.691 | 0.738 | 0.737 | 0.682 | −0.653 | −0.703 | 1 | |
Wind | 0.279 | 0.466 | 0.292 | 0.372 | 0.156 | 0.382 | 0.321 | −0.344 | −0.307 | 0.324 | 1 |
Cl−
| NO2
−
| NO3
−
| SO4
2−
| Na+
| NH4
+
| K+
| Mg2+
| Ca2+
| Pre | Wind | |
---|---|---|---|---|---|---|---|---|---|---|---|
Cl−
| 1 | ||||||||||
NO2
−
| 0.417 | 1 | |||||||||
NO3
−
| 0.200 | 0.194 | 1 | ||||||||
SO4
2−
| 0.181 | 0.265 | 0.977** | 1 | |||||||
Na+
| 0.962** | 0.337 | −0.048 | −0.075 | 1 | ||||||
NH4
+
| 0.674 | 0.143 | 0.653 | 0.698 | 0.495 | 1 | |||||
K+
| 0.963** | 0.410 | 0.395 | 0.401 | 0.876* | 0.826* | 1 | ||||
Mg2+
| 0.067 | 0.287 | 0.966** | 0.984** | −0.178 | 0.570 | 0.288 | 1 | |||
Ca2+
| 0.057 | 0.326 | 0.961** | 0.979** | −0.191 | 0.544 | 0.270 | 0.998** | 1 | ||
Precipitation | −0.635 | −0.008 | −0.636 | −0.669 | −0.473 | −0.987** | −0.794 | −0.543 | −0.508 | 1 | |
Wind | 0.971** | 0.537 | 0.285 | 0.271 | 0.891* | 0.675 | 0.936** | 0.158 | 0.162 | −0.604 | 1 |
The main control factor of ion composition of fresh snow
Component | Initial eigenvalues | Component | |||||
---|---|---|---|---|---|---|---|
Total | % of variance | Cumulative % | 1 | 2 | 3 | ||
1 | 5.855 | 65.053 | 65.053 | Cl−
| 0.964 | 0.261 | −0.028 |
2 | 2.077 | 23.076 | 88.129 | NO2
−
| 0.281 | −0.248 | 0.927 |
3 | 1.034 | 11.492 | 99.621 | NO3
−
| 0.953 | 0.297 | 0.007 |
4 | 0.033 | 0.363 | 99.983 | SO4
2−
| 0.998 | −0.002 | 0.068 |
5 | 0.002 | 0.017 | 100.000 | Na+
| 0.937 | −0.061 | −0.329 |
6 | 2.306E−16 | 2.562E−15 | 100.000 | NH4
+
| 0.995 | −0.083 | 0.057 |
7 | −6.547E−17 | −7.274E−16 | 100.000 | K+
| 0.999 | 0.041 | −0.027 |
8 | −1.887E−16 | −2.096E−15 | 100.000 | Mg2+
| −0.133 | 0.956 | 0.238 |
9 | −5.046E−16 | −5.606E−15 | 100.000 | Ca2+
| −0.245 | 0.966 | −0.007 |
Component | Initial eigenvalues | Component | ||||
---|---|---|---|---|---|---|
Total | % of variance | Cumulative % | 1 | 2 | ||
1 | 4.975 | 55.273 | 55.273 | Cl−
| 0.561 | 0.821 |
2 | 2.958 | 32.871 | 88.144 | NO2
−
| 0.430 | 0.243 |
3 | 0.908 | 10.092 | 98.236 | NO3
−
| 0.897 | −0.393 |
4 | 0.142 | 1.576 | 99.812 | SO4
2−
| 0.914 | −0.402 |
5 | 0.017 | 0.188 | 100.000 | Na+
| 0.332 | 0.933 |
6 | 3.770E−16 | 4.189E−15 | 100.000 | NH4
+
| 0.852 | 0.258 |
7 | 2.176E−16 | 2.418E−15 | 100.000 | K+
| 0.732 | 0.675 |
8 | −1.471E−16 | −1.635E−15 | 100.000 | Mg2+
| 0.859 | −0.504 |
9 | −5.339E−16 | −5.932E−15 | 100.000 | Ca2+
| 0.851 | −0.512 |
Conclusions
-
1. The pH of fresh snow was within the range of 6.27–7.01 and lower in rainy season because of continuous leaching of frequent precipitation. The conductivity in dry season was much higher than that in rainy season.
-
2. The concentration of inorganic ions was generally higher in dry season than that in rainy season. Ca2+ and Mg2+ reached its peak concentration from December to February of the following year, while the highest concentration of other ions occurred in pre-monsoon period (April–May).
-
3. The ions of fresh snow in dry seasons mainly came from terrestrial under the influence of west wind circulation and the Plateau monsoon. Southeast and southwest monsoons greatly affected the area in rainy season.
-
4. Bedrock composition, human activities and marine aerosol transport together with the water vapor were the principal inorganic ion sources of Baishui No. 1 Glacier.