Roundup: Glacier Freshwater, Bearded Seals and Metal Contamination

Impact of Glacier Freshwater on Sea Ice Melting in Antarctica

From Journal of Ocean Modelling: “The Impact of glacial freshwater on sea ice is studied with a sea ice/ocean/iceberg model. The ice shelves mass change is included for the first time in the freshwater perturbation. Changes in freshwater input increase sea ice cover with distinctive regional pattern. The impact of freshwater on sea ice volume was found to be comparable to atmosphere-induced changes. Freshwater was found to be able to decrease Antarctic sea ice in Amundsen sector through ocean vertical circulation. The results suggest a need for improving the representation of freshwater sources and their evolution in climate models.”

Learn more about the impact of glacier meltwater in the Southern Ocean here.

Time series anomalies of (a) sea ice extent due to atmospheric induced changes and (b) sea-ice volume due to freshwater induced changes (Source: Merino et al/Science Direct)
Time series anomalies of (a) sea ice extent due to atmospheric induced changes and (b) sea-ice volume due to freshwater induced changes (Source: Merino et al./Science Direct).

 

Sounds of Bearded Seals in Glacier and Non-Glacier Environments

From Journal of the Acoustical Society of America: “In this study the description of underwater vocal repertoire of bearded seal in Svalbard (Norway) was extended. Two autonomous passive acoustic recorders were deployed for one year (August 2014–July 2015) in the inner and outer parts of the Kongsfjorden, and 1728 h were recorded and 17 220 vocalizations were found. Nine different vocalization classes were identified and characterized using ten acoustic parameters. This study represents a step forward to improve the understanding of the acoustic behaviour and the social function of these calls, and the ecology of marine species producing sounds.”

Discover the difference in acoustic behavior of bearded seals as a result of their external environments here.

Bearded Seal in Svalbard (Ali Schneider/Pinterest)
A bearded seal in Svalbard (Source: Ali Schneider/Pinterest).

Metal Contamination in Glacier Lakes of Tibet

From Journal of Environmental Science and Pollution Research: “Heavy metal contamination has affected many regions in the world, particularly the developing countries of Asia. We investigated 8 heavy metals (Cu, Zn, Cd, Pb, Cr, Co, Ni, and As) in the surface sediments of 18 glacier lakes on the Tibetan Plateau. Principal component analysis, hierarchical cluster analysis, and Pearson correlation analysis results indicated that the 8 heavy metals in the lake surface sediments of the Tibetan Plateau could be classified into four groups. Group 1 included Cu, Zn, Pb, Co, and Ni which were mainly derived from both natural such as glacier meltwater and traffic sources. Group 2 included Cd which mainly originated from anthropogenic sources like alloying, electroplating, and dyeing industries and was transported to the Tibetan Plateau by atmospheric circulation. Group 3 included Cr and it might mainly generate from parent rocks of watersheds. The last Group (As) was mainly from manufacturing, living, and the striking deterioration of atmospheric environment of the West, Central Asia, and South Asia.”

Read more about the distribution of metal contaminants and their sources here.

Yangzhoyong Co, one of the lakes featured in the study (Source: China News/Twitter)
Yangzhoyong Co, one of the lakes featured in the study (Source: China News/Twitter).

Seasonal Lake Changes on the Tibetan Plateau

Kunlun Mountain Chains (source: Yunsheng Bai / Flickr).
Kunlun Mountains (source: Yunsheng Bai/Flickr).

The Kunlun Mountains, featured as a mythical location in the legendary Chinese text Shanhai Jing, are one of the longest mountain chains in Asia. From the Pamirs of Tajikistan, the mountains run east along the border of Xinjiang and Tibet to the Qinghai province, forming part of the Tibetan Plateau. A number of important glaciers and lakes are found in the area, attracting glaciology researchers to the region throughout the year. Yanbin Lei, an associate research fellow at the Chinese Academy of Sciences, is one scientist conducting important field work in the region.

Recently, Lei et al. published a paper  in the American Geophysical Union Journal Geophysical Research Letters that describes how lakes in the Tibetan Plateau are growing and deepening due to climate change. In particular, the scientists identified two patterns of lake level seasonality.

Because the climate is warming, an earlier melt and a relatively large increase in spring runoff are observed for all scenarios. This in turn increases water availability in the Indus Basin irrigation scheme during the spring growing season, according to Lei et al. This finding projects that rainfall will increase, according to another study by Su er al. In addition,  the discharge in the major large rivers of South and East Asia will also increase.

Kotra Tso at the Kunlun Mountains (source: Dr. Yongjie Wang).
Kotra Tso at the Kunlun Mountains (source: Yongjie Wang).

“Though crucial, the paucity of instrumental data from the sparsely populated Tibetan Plateau has limited scientific investigations of hydroclimate response to recent climate change,” Lei told GlacierHub. The Tibetan Plateau has a large spatial coverage and high elevation (the average latitude is over 4000 meters), not to mention an incredibly harsh climatic condition, which makes conducting research and taking measurements difficult. Because the seasonal dynamics of the lakes is not sufficiently understood, the research conducted by Lei et al. in the Tibetan Plateau was unprecedented.

“In general, there is a lack of monitoring of lake levels in the Kunlun Mountains, and consequently, data is missing for the lakes,” Lei  added. “Even if remote sensing were developed as a major method for studying inter-annual changes of lakes, the accuracy and frequency of this method would still be limited to study seasonal changes.”

With the help of “situ observations,” Cryosat-2 satellite altimetry data between 2010 and 2014, and Gravity Recovery and Climate Experiment (GRACE) data, Lei et al. managed to identify two patterns of lake level seasonality. “In the central, northern, and northeastern Tibetan Plateau, lake levels are characterized by considerable increases during warm seasons and decreases during cold seasons, which is consistent with regional mass changes related to monsoon precipitation and evaporation,” Lei et al. describe in their paper.  “In the northwestern Tibetan Plateau, however, lake levels exhibit dramatic increases during both warm and cold seasons, which deviate from regional mass changes.”

In an interview with GlacierHub, Lei summarized the reasons for this finding: “The difference was mainly caused by the glaciers and precipitation. There are widespread glaciers in the northwest Tibetan Plateau and the area of glaciers is larger than the area of lakes. The precipitation in summer is also low, resulting in high spring snowfall and large summer glacier melt to feed the lake. Meanwhile, in the northern Tibetan Plateau, there are fewer glaciers but more summer rainfall, causing an increase in the lake level,” Lei told GlacierHub.

The location of the selected lakes in the NWTP, NTP, CTP, and NETP (source: Lei et al. / Wiley).
The location of the selected lakes in the NWTP, NTP, CTP, and NETP (source: Lei et al. /Wiley).

Additionally, the seasonal difference of precipitation is also important. Annual precipitation in the northern Tibetan Plateau is 300-400 mm with 90 percent of precipitation occurring in summer, according to Lei. Annual precipitation in the northwest Tibetan Plateau is about 200 mm because spring snowfall counts more. “The lake level responses to different drivers indicates heterogeneous sensitivity to climate change between the northwestern Tibetan Plateau and other regions,” Lei noted.

As Lei et al. demonstrate in their study, climate change has dramatically influenced the lakes and rivers of Tibet. Higher temperatures saliently have led to the expansion of the watershed. However, Lei is unsure about the exact effect of climate change.

“Since 2006, lakes in the central Tibetan Plateau have been stable, while lakes in the northern Tibetan Plateau and Northwest Tibetan Plateau are growing at a high speed,” he said. “When these lakes will reach equilibrium remains uncertain.”

Roundup: Peruvian Climate, Tibetan Lakes, and Greenland’s Glaciers

Roundup: Peru, Tibet and Greenland

 

Project to Improve Climate Services in Peru

From Climate Services: “CLIMANDES is a pilot twinning project between the National Weather Services of Peru and Switzerland (SENAMHI and MeteoSwiss), developed within the Global Framework for Climate Services of the World Meteorological Organization (WMO). Split in two modules, CLIMANDES aims at improving education in meteorology and climatology in support of the WMO Regional Training Center in Peru, and introducing user-tailored climate services in two pilot regions in the Peruvian Andes… The efforts accomplished within CLIMANDES improved the quality of the climate services provided by SENAMHI.”

Read more about CLIMANDES here.

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Landscape of the Peruvian Andes from behind walls of Machu Piccu (Source: Mariano Mantel/Creative Commons).

 

Monitoring Lake Levels on the Tibetan Plateau

From Journal of Hydrology: “Lakes on the Tibetan Plateau (TP) are of great interest due to their value as water resources but also as an important indicator of climate change. However, in situ data in this region are extremely scarce and only a few lakes have gauge measurements… In this study, Cryosat-2 SARIn mode data over the period 2010–2015 are used to investigate recent lake level variations… Lakes in the northern part of the TP experienced pronounced rising (avg. 0.37 ± 0.10 m/yr), while lakes in southern part were steady or decreasing even in glaciated basins with high precipitation… These results demonstrate that lakes on the TP are still rapidly changing under climate change, especially in northern part of the TP, but the driving factors are variable and more research is needed.”

Learn more about climate change on the Tibetan Plateau here.

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Aerial view of lakes of the Tibetan Plateau (Source: Stuart Rankin/Creative Commons).

 

Data Portal to Study Greenland’s Ice Sheet

From Eos: “A new web-based data portal gives scientists access to more than 40 years of satellite imagery, providing seasonal to long-term insights into outflows from Greenland’s ice sheet… This portal harnesses more than 37,000 images from Landsat archives, dating back to the early 1970s, to track changes in outlet glaciers over time… Through analyzing data from this portal, we can see in great detail how several outlet glaciers are speeding up their treks to the sea. What’s more, any user can access the data to conduct their own studies of glacier behavior at Greenland’s coasts through time.”

Read more about Greenland’s retreating glaciers here:

Aerial view of coastal Greenland glacier (Source: Terry Feuerborn/Creative Commons).
Aerial view of a coastal Greenland glacier (Source: Terry Feuerborn/Creative Commons).