Modeling of Mass Balance Variability and Its Impact on Water Discharge from the Urumqi Glacier No. 1 Catchment, Tian Shan, China

Originating in the Tian Shan mountains, Urumqi River plays a key role in terms of water supply to downstream areas. In its headwaters, Urumqi Glacier No. 1 (UG1) is the largest glacier contributing to water discharge. Assessing its response to the changing climatic conditions in the area is of major importance to quantify future water availability. We here apply COSIPY, a COupled Snowpack and Ice surface energy and mass balance model in PYthon, to UG1, implementing a new albedo parameterization which integrates site-specific bare-ice albedo values on a pixel-by-pixel basis observed by remote sensing. We assess model performance threefold: quantitatively based on long-term measurement data of (1) surface mass balance (SMB) and (2) water discharge as well as qualitatively (3) comparing simulated snow line altitudes to such imated on the basis of time-lapse photography. Comparison of the modeled SMB with annually-averaged data from ablation stakes reveals that COSIPY including the new albedo parameterization accounts for 57.6% of the variance observed in the measurements. The original albedo parameterization performs only slightly inferior (57.1%). Glacier-wide comparison between modeled and glaciological SMB shows high agreement. In terms of discharge prediction, COSIPY reproduces onset and duration of the discharge season well. Estimated discharge from the whole catchment shows shortcomings in exactly matching the measured times series, but interannual variability is captured.Peer Reviewe

Sea Level Pressure Variability Over the Southern Indian Ocean Inferred from a Glaciochemical Record in Princess Elizabeth Land, East Antarctica

A 250-year, high-resolution, multivariate ice core record from LGB65 (70degrees50\u2707 S, 77degrees04\u2729 E; 1850 m asl), Princess Elizabeth Land (PEL), is used to investigate sea level pressure (SLP) variability over the southern Indian Ocean (SIO). Empirical orthogonal function (EOF) analysis reveals that the first EOF (EOF1) of the glaciochemical record from LGB65 represents most of the variability in sea salt throughout the 250-year record. EOF1 is negatively correlated (95% confidence level and higher) to instrumental mean sea level pressure (MSLP) at Kerguelen and New Amsterdam islands, SIO. On the basis of comparison with NCEP/NCAR reanalysis, strong correlations were found between sea-salt variations and a quasi-stationary low that lies to the north of Prydz Bay, SIO. Comparison with a 250-year-long summer transpolar index (STPI) inferred from sub-Antarctic tree ring records reveals strong coherency. Decadal-scale SLP variability over SIO suggests shifting of the polar vortex. Prominent decadal-scale deepening of the southern Indian Ocean low (SIOL) exists circa 1790, 1810, 1835, 1860, 1880, 1900, and 1940 A. D., continuously after the 1970s, and prominent weakening circa 1750, 1795, 1825, 1850, 1870, 1890, 1910, and 1955 A. D. The LGB65 sea-salt record is characterized by significant decadal-scale variability with a strong similar to21-year periodic structure (99.9% confidence level). The relationship between LGB65 sea salt and solar irradiance changes shows that this periodicity is possibly the solar Hale cycle ( 22 years)

Climatological Significance of δ\u3csup\u3e18\u3c/sup\u3eO in Precipitation and Ice Cores: a Case Study at the Head of the Ürütnqi River, Tien Shan, China

Stable-oxygen-isotope ratios (δ18O) collected from the headwaters of the Ürümqi river, Tien Shan, China, were used to test the relationship between δ18O temporal relationship is found between δ18O monthly averages which remove synoptic-scale influences such as changes in condensation level, condensation temperature and moisture sources (Yao and others, 1996). Linear fits as high as 0.95‰°C-1 for precipitation events and 1.23‰°C-1 for monthly averages are found. Although the δ18O (∼2 km from the precipitation sampling site) decreased dramatically compared to the precipitation samples , the ice-core records of annually averaged δ18O with contemporaneous air temperature, especially summer air temperature, at the nearby Daxigou meteorological station. Nevertheless, the relationship between the ice core δ18O records and contemporaneous air temperature is less significant than that [or the precipitation samples due to depositional and post-depositional modification processes, which are highlighted by the successive snow-pit δ18O No. 1. Our results might extend the application of high-altitude and subtropical ice-core δ18

Soluble Species in Aerosol and Snow and Their Relationship at Glacier 1, Tien Shan, China

Simultaneous sampling of aerosol (n = 20) and snow (n = 114) was made at Glacier 1, Tien Shan, between May 19 and June 29, 1996. Similar temporal patterns of some major ion (calcium, magnesium, potassium, sodium, chloride, and sulfate) concentrations between snow and aerosol show that snow chemistry basically reflects changes in the chemistry of the atmosphere. This gives us confidence in the reconstruction of past atmospheric change using some snow data. There are no significant correlations between aerosol and snow samples for ammonium and nitrate. This suggests that postdepositional and/or postcollection processes may alter ammonium and nitrate concentrations in snow. The fact that the measured cations in aerosol and snow always exceed the measured anions suggests that the atmosphere is alkaline over Glacier 1, Tien Shan. In aerosol and snow samples, calcium is the dominant cationic species, with sulfate and presumed carbonate being the dominant anions. There is a very good inverse relationship (r = 0.96) between the equivalence ratio of calcium to sulfate and the ratio of ammonium to sulfate in aerosols, but this relationship does not hold for snow. This further suggests that postdepositional and/or postcollection processes exert important controls on ammonium concentrations in snow. Although melt-freeze cycles might increase the concentration of all crustal species through progressive dissolution of dust, these cycles seem most important for magnesium and carbonate

Investigation on Social Anxiety of Secondary Vocational Students

Objective: To investigate the status quo of social anxiety among secondary vocational students and the differences in demographic variables through the Communication Anxiety Scale (IAS) survey. Methods: A total of 890 students from a secondary vocational school in Changshou District of Chongqing were surveyed with the Communication Anxiety Scale (IAS) to understand the social anxiety of secondary vocational students. Results: The mean score of social anxiety of secondary vocational students was 45.25±9.32. The gender difference of social anxiety in secondary vocational students was significant (P0.05); The social anxiety of secondary vocational students was significantly different in household registration type (P0.05). The difference of social anxiety in family income of secondary vocational students was very significant (P<0.001). Conclusion: The level of social anxiety of secondary vocational students is above the middle level. From the perspective of gender variables, there is a significant difference in the level of social anxiety between male and female students, and the level of social anxiety of male students is significantly lower than that of female students. In terms of grade variables, there was no significant difference in social anxiety in grade variables. From the perspective of the variable of residence type, social anxiety is significantly different between rural students and urban students. The level of social anxiety of rural students is higher than that of urban students. There is no significant difference between only-child and non-only-child in social anxiety. From the perspective of family income level, social anxiety is significantly different among different income families. Students from families with wages higher than the average social level had the lowest level of social anxiety, students from families with wages comparable to the average social level had higher levels of social anxiety, and students from families with wages lower than the average social level had the highest level of social anxiety.