Development of a simple snow load gauge using plastic bottles

Abstract

Previous research has demonstrated the high variations of the surface albedo in winter/spring in snow-covered regions in various global climate models. In this study, we focus on the surface albedo over snow-covered forests which is suggested probably too high in various global climate models. This study was carried out to verify the occurrence frequency of ice accretion and snow accretion in the boreal forest regions. Using the interval camera installed on the observation tower of 16 m in height at the site located to the north of Fairbanks, Alaska, ice accretion and snow accretion in black spruce forest regions were measured. Based on the results, the surface albedo variation of snow-covered forests and differences in the snow albedo parameterization are discussed to contribute to a better understanding of the role of snow in the climate system. On March 12, 2011, a large earthquake induced rock avalanches in Nagano and Niigata prefecture Japan. These rock avalanches travelled long, about 1 km to 1.5 km sliding on snow with apparent friction angle of 6? to 17.1?. It looks un-common phenomena. Because rock avalanches often stop on snow covering steep slope. We hypothesized that the nature of snow dominate the mobility of the rock-on-snow avalanche, and flew rocks on snow 3.5-m-long slope varying snow hardness, and then we flew a rock and earth of 6 ton on 28-m long snow covering slope. Snow is low friction material but its aggregates is effective cushion by self-deformation, so travelling on normal autochthonous snow cover and mixing snow into the falling material do not contribute such long travelling. However, hardened and consolidated snow provide it because of ice-like low friction and impermeability. The consolidated snow is formed at the contact surface on snow cover by impulsive compressing. Hence, when a falling material plunge into lower thick snow cover, consolidated snow is formed. Then, falling material slide on it by pushing following flow. When the forming consolidated snow basement, water and air are expelled from snow to upper falling material, and they probably reduce friction. As the consolidated snow is impermeable, frictional heat and heart transfer-ring produced snowmelt are kept on the consolidated snow, and it reduce further friction. With downsizing of falling material, the resistivity against forehand snow cover decreases, and it leads to stopping. In addition, with lessening pressure of the falling material to underlying snow cover, forming impermeable consolidated snow stops, and water pressure disappear, and it leads to stopping. Wet and granular snow is likely to be consolidated. Thus these snow covered area and/or season are preferable condition of the long travelling rock-on-snow avalanches. The glacier and mountain permafrost research expedition was carried out in September and October of 2014 in the central part of the Bhutan Himalayas. The aims of this expedition were 1) to make a rock glaciers inventory and identify the lower limit of mountain permafrost in the Bhutan Himalayas, and 2) to measure the ice thickness of the Gangjula glacier based on the ground penetrating radar (GPR) soundings. We identified total 81 rock glaciers. Active rock glaciers appeared above 4600 m. We estimated that mean annual air temperature at the terminus of the active rock glaciers are less than -0.8oC based on ERA-Interim data from 1979 to 2013. These indicate that the lower limit of mountain permafrost in Bhutan Himalayas is 4600 m. This lower limit of mountain permafrost is slightly lower than that in Khumbu Himal (5000-5300 m) and that in Kanchenjunga Himal (4800 m). The Gangjula glacier is a small saddle glacier. Length=1.1 km, width=0.3 km, surface area=0.31km 2 , elevation=4900-5200 m and the ELA=glacier top. We used GSSI SIR3000 + 100MHz antenna and got 6 cross and 1 longitudinal GPR profiles. The results of GPR soundings indicated that the maximum thickness of the Gangjula glacier was 76 m. Patagonia Icefields are loosing ice mass at one of the greatest rates in the world. The icefields are characterized by a number of outlet glaciers calving into lakes and the ocean. Many of these calving glaciers are retreating, but rates of the retreats are significantly different in each glacier. For example, Glaciar Upsala retreated by 2.9 km over the period of 2008 ̶ 2011. Mass loss from the glacier accounts for about 15% of the total mass loss from the Southern Patagonia Icefield in 2000 ̶ 2012. On the other hand, Glaciar Perito Moreno has shown no significant change in the terminus position over the past century. Recent studies in Greenland and Alaska suggest the importance of melting of calving face below the sea surface for recent mass loss of calving glaciers. Despite the increasing numbers of data from fjord of tidewater glaciers, little is known even in the thermal structure in lake, seasonal variation and how various water masses mix. To investigate the thermal structure of proglacial lake, we measured temperature and turbidity of lake water in front of calving glaciers in the Southern Patagonia Icefield. Lake measurements were carried out at Glaciar Upsala, which overs an area of 840 km 2 and flows into a ∼ 600 m deep lake, and Glaciar Perito Moreno, which overs an area of 259 km 2 and flows into a shallower lake ( ∼ 200 m deep). We repeated measurements in summer (December, 2013) and spring (October, 2014) to investigate seasonal variations in the lake water properties. Our results in spring showed relatively uniform water temperature and turbidity from the lake surface to the bottom, whereas temperature and turbidity showed steeper vertical gradients in summer. These results are consistent in the two lakes. In summer, water temperature in front of Glacier Upsala (2 ̶ 4 o C) was colder than in spring, because of large amounts of subglacial discharge from the glacier. Turbid and cold water ( < 1 o C) was found at the deepest part of the lake ( > 500 m below the lake surface), which is a strong indication of subglacial meltwater discharge. Contrasting to Glaciar Upsala, cold deep water was missing in the lake of Glaciar Perito Moreno both in summer and spring. In summer, water temperature (6 o C) was warmer than in spring by ∼ 3 o C within whole lake, and in particular, warm water layer ( ∼ 8 o C) observed at the lake surface ( < 5 m below the lake surface). These data indicate different thermal structures in front of the two freshwater calving glaciers in Patagonia. The structure is probably dependent on the bathymetry and subglacial discharge. Warmer lake is formed by relatively small amount of subglacial discharge and shallow lake, which should play crucial roles in the melting of calving face below