ACC20-P01

Japan Geoscience Union Meeting 2016

Development of snow algorithm based on the microwave radiative transfer model for multiple
layers and various land surface parameters*Hiroyuki Tsutsui1
1. Japan Aerospace Exploration Agency/Earth Observation Research Center
Many snow retrieval algorithms based on the microwave remote sensing uses the microwave radiativetransfer model (RTM) for a single snow layer structure and a lot of assumption for land surface
parameters. We could not achieve the high estimation accuracy because our algorithm also has usedsame structure. Therefore, our RTM was modified as follows: Until now, the combined model of theDense Media Radiative Transfer model (Tsang, 1992) and the 4-Stream fast model (Liu, 1988) was usedin our RTM. In this study, the Advanced Integral Equation Model (AIEM; Chen, 2001) was added to RTM
in order to evaluate the land surface scattering, and the multiple layer for snow and soil wasapplied in order to evaluate various parameter. For the vegetation, a vegetation water content iscalculated by the Paloscia and Pampaloni (1988)’s empirical formula, and a vegetation optical
thickness is calculated by Jacson and Schmugge (1991)’s empirical formula. Thereafter, it isevaluated by the Omega - Tau model (Mo et al., 1982). Furthermore, ice’s component was added into
the Dobson et al. (1985)’s empirical formula in order to evaluate the soil freezing. Afterward, thesensitivity of RTM was checked in order to reduce of assumption parameters. In consequence, theporosity, ice content, snow temperature gradient for soil and the LAI and vegetation fraction forvegetation were applied as the land surface parameters. Subsequently, the lookup tables (LUT) for
each land surface parameter were calculated by the modified RTM, and the snow retrieval algorithm,
which estimates snow depth using the brightness temperature for 18.7/36.5GHz, was developed. Snow
particle size was calculated by the snow grain growth model (Sturm and Benson, 1977), and snow
temperature is calculated by the Richard (2003)’s empirical formula using the AMSR2 brightness
temperature for 18.7(v), 23.8(v), 36.5(h) and 89.0(v) GHz. Furthermore, the Harmonized World Soil
Database, the NSIDC Permafrost global map, the MODIS LAI map, the ESA Glob Cover Dataset wereapplied as the global ancillary data. Algorithm performance was validated from October 2012 toFebruary 2013 at the Siberia 11 ground-based stations over the Siberia region (N55-65°, E125-135°),
and the estimated snow depth was in good agreement with the in situ data. In the result, thedeveloped algorithm was achieved MAE (Mean Absolute Error):9cm, Bias:1.5cm and RMSE:14cm.
Keywords: Snow, Microwave remote sensing, Algorithm©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P01 -ACC20-P02

Japan Geoscience Union Meeting 2016

A 30-year trend of snow cover duration in the Northern Hemisphere derived fromsatellite-borne optical sensors*Masahiro Hori1, Konosuke Sugiura2, Tomonori Tanikawa3, Teruo Aoki3, Katsuyuki Kuchiki3, Masashi
Niwano3, Hiroyuki Enomoto4,5
1.Earth Observation Reseacrh Center, Japan Aerospace Exploration Agency, 2.University of Toyama,
3.Meteorological Research Institute, 4.National Institute of Polar Research, 5.The Graduate
University for Advanced Studies
Snow cover extent (SCE) has been an important observation target from space for weather prediction
since 1960’s. The National Oceanic and Atmospheric Administration (NOAA) has produced a historic
record of weekly SCE charts in the Northern Hemisphere over three decades. The NOAA SCE has been
widely used for climate studies. However, the production method of SCE has not been unified during
the long-term operations. Thus, the accuracies of SCE detection are considered changeable. As analternative product, a 30-year long SCE was derived in this study from radiances acquired with
optical sensors onboard polar orbiting satellites by employing an objective analysis method. Thatis, only five spectral channels which are available during the whole analysis period were used for
SCE detection. In addition to SCE, snow melt date (SMD), first snow date (FSD), and snow cover
duration (SCD) were also derived from the SCE. The derived SCE exhibits negative trends in allseasons, which is partly inconsistent with those derived from NOAA SCE. The causes of theinconsistency are considered due to the coarser spatial resolution of NOAA SCE (i.e., pixel size isapproximately 190 km whereas this study’s SCE has 5km spatial resolution) and also due to thechangeable snow detection accuracy. The trend of the derived SCD exhibits spatially asymmetricpattern over the Northern Hemisphere. That is, significant shortening occurs in western part ofEurasian Continent (EC), whereas weak shortening or even lengthening occurs in eastern EC andwestern North America Continents. From the comparison with SMD and FSD, the significant shortening
in western EC is considered to be caused mainly by the delay of FSD toward later dates in autumn
and partly by the advancement of SMD toward earlier dates in spring. The long-term SCE dataset will
be used as a climatological baseline for a Japanese satellite mission named “Global Change
Observation Mission-Climate” (GCOM-C) to be launched in 2017.
Keywords: Snow Cover, Snow Cover Duration, Remote Sensing, Climate, GCOM

©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P02 -ACC20-P03

Japan Geoscience Union Meeting 2016

Movement analysis of curling stone*Katsutoshi Tusima, Katsunori Mori

youtube on curling world championship was analyzed. curl distance c, angle of spin n and sliding
distance s are measured as a function of sliding time t. in initial stage, stone went to linearly,
and curl started at middle stage in the neighborhood of 12 second before stop. curl distance(lateral displacement) increased linearly to sliding time t, reached abut 1 m at end. stone turned
at 6 to 10 second as increasing time with sliding. coefficient of friction for spin was extremely
small and estimated to order of 0.0001 to 0.00001. coefficient of friction f was value of 0.009 to
0.02 with increasing as decreasing velocity. curves c-s, f-s and f-v were derived.
Keywords: curling, ice, curl©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P03 -ACC20-P04

Japan Geoscience Union Meeting 2016

Development of a simple snow load gauge using plastic bottles (part 2)*Yuichi Imanishi1, takuma oi2, Katsuhisa Kawashima3, Takane Matsumoto3, Osamu Suzuki4
1.Earthquake Research Institute, The University of Tokyo, 2.Toho Mercantile CO., LTD., 3.ResearchInstitute for Natural Hazards and Disaster Recovery, Niigata University, 4.Research and Development
Center, East Japan Railway Company
Imanishi and Oi (2015) developed a simple snow load gauge using plastic bottles with the purpose ofcorrecting hydrological effects on precise gravity observations. So far we have made laboratory
tests by artificially loading the instrument as well as field experiments near the Kamioka gravity
station. However, there have been no opportunities of comparing it with other instruments orvisually inspecting the status of the instrument under snow load. In this winter, we have installed
the instrument at the Oshirakawa Meteorological Station, jointly maintained by Niigata University
and East Japan Railway Company, in order to make parallel observations with a snow pressure pillow(metal wafer). As of this writing, the plastic bottle instrument is indicating temporal increase ofload that is likely to correctly reflect accumulation of snow. Results of detailed comparison withthe snow pressure pillow will be presented.
Keywords: snow load gauge, superconducting gravimeter, plastic bottle©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P04 -ACC20-P05

Japan Geoscience Union Meeting 2016

Monitoring of snow albedo and ice surface temperature in the North-West Greenland using
MODIS data
*Tomonori Tanikawa1, Teruo Aoki1, Masashi Niwano1, Masahiro Hori2, Wei Li3, Nan Chen3, Knut Stamnes3
1.Meteorological Research Institute, 2.Japan Aerospace Exploration Agency, 3.Stevens Institute ofTechnology
Much works in the Greenland ice sheet (GrIS) have reported recent Arctic warming. The GrIS has been
experiencing extensive melt. The surface melt extent can be seen especially in northwestern
Greenland. Such an event results in increasing the ice surface temperature as well as decreasing
the snow surface albedo. It makes a large contribution to the ice-albedo feedback in the total meltenergy. Thus, the monitoring of snow surface albedo and the ice surface temperature in thenorthwestern GrIS by using NASA’s optical sensor MODIS data are important. We developed algorithms
to retrieve the snow surface albedo and the ice surface temperature based on the radiative transfer
model of atmosphere-snow system. We employed the MODIS (Collection 6) images to show temporal andspatial variation in more detail. We built monthly composite MODIS images by collecting clear day(cloud-free) pixels, and then estimated the snow surface albedo and the ice surface temperaturefrom 2002 to 2014. Results show that the edge of the ice sheet was confirmed to be both low visible
and near-infrared albedo through May to September in common. This implies that there are a dark
region and a surrounding blue ice area. These low-albedo areas were gradually expanded toward theinland during recent 13 years. For the ice surface temperature, the edge of the ice sheet wasmeasured to be almost melting point, and these areas were also gradually expanding toward theinland. This means that there is a potential of melting the ice sheet and increasing snow grain
size over a wide area, resulting in the accelerate near-infrared albedo reduction more rather now.
At SIGMA-A site (N78º03’06”/W67º37’42”; 1490 m a.s.l.) where an automate weather station was
installed in 2012, a significant negative trend in both visible and near-infrared albedo reduction
can be seen in the melting season. Both albedo reduction was largest in August. As corresponding toalbedo changes, the positive trend of the ice surface temperature can be seen in the melting
season. Comparison between SIGMA-A site and NEEM (N77º30’08”/ W58º04’22”; 2454 m a.s.l.) site showsthat the positive (negative) trends for the near-infrared albedo (ice surface temperature) werecommon each other while that for the visible albedo were different. In NEEM site, small positive
trends can be seen in the visible albedo. If major surface melt events such as 2012 summer andincreasing the ice surface temperature trend will be measured in the near future, it may cause theexpansion of the melting snow area toward the inland, and thereby decreasing the snow surface
albedo can be observed in the NEEM site as well after increasing the snow grain size. So, we willcontinue to focus on these areas to monitor snow physical parameters. In addition we will attempt
to use a Japanese satellite mission named "Global Change Observation Mission-Climate (GCOM-C)" tobe launched in 2017 which may help to be aimed at a more temporal/spatial detailed monitoring ofthese parameters.
Keywords: Snow albedo, Ice surface temperature, Greenland, Remote sensing©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P05 -ACC20-P06

Japan Geoscience Union Meeting 2016

Spatial distribution of mountain permafrost in northern Tien Shan, Central Asia
Akiko Yamamura1, *Chiyuki Narama1, Nobuhiro Tomiyama2, Takeo Tadono3, Tsutomu Yamanokuchi2
1.Niigata University, Graduate school of Science and Technology, 2.RESTEC, 3.JAXA
To clarify the current state of mountain permafrost, we researched the distribution,
classification, and movement of rock glaciers as an indicator of mountain permafrost in the Kyrgyz
Ala-Too Range using field survey, GIS/RS techniques and aerial photograph interpretation. At theexamined site, MAAT is -4.62 and MAGST is -1.47 on rock glacier (3500 m asl.) showing environmentof mountain permafrost. The distribution of rock glaciers shows the discontinuous permafrost zones
are located above 2800 m a.s.l. on the north part and above 3200 m on the south part of the Kyrgyz
Ala-Too Range.
Keywords: mountain permafrost, rock glacier, DInSAR©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P06 -ACC20-P07

Japan Geoscience Union Meeting 2016

Estimation of sulfur source contribution to sulfate aerosol in surface snow in East
Antarctica using sulfur isotope analysis*Ryu Uemura1, Kosuke Masaka1, Kotaro FUKUI2, Yoshinori Iizuka3, Motohiro Hirabayashi4, Hideaki
Motoyama4
1.University of the Ryukyus, 2.Tateyama Caldera Sabo Museum, 3.Institute of Low Temperature
Science, Hokkaido University, 4.National Institute of Polar Research
Sulfur stable isotope ratio (δ34S) of sulfate aerosol provides important information to assess
contributions from various sources. Despite several observations in Antarctica, spatial
distribution of sulfur isotopes in Antarctica, however, still remain unclear. Here, we present thefirst sulfur isotope data of surface snow along latitudinal transect in east Dronning Maud land,
East Antarctica. The δ34S values showed homogeneous values without significant relationship between
δ34S and latitudes, suggesting that isotopic fractionation during transportation is insignificant.
Based on the δ34S value and ion concentrations, the contribution of marine biogenic sulfur tosulfate aerosol is dominant.
Keywords: sulfate aerosol, Antarctica, sulfur isotope©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P07 -ACC20-P08

Japan Geoscience Union Meeting 2016

Downwasting of debris-covered ablation area of Lirung Glacier in Langtang Valley, Nepal
Himalayas since 1979
*Takayuki Nuimura1, Koji Fujita2, Akiko Sakai2
1.Chiba Institute of Science, 2.Graduate School of Environmental Studies, Nagoya University
Larger number of glacier system in Himalayas plays important role to water supply in surrounded
country and global sea level rise. Extensive glacier mass change have been measured in various
scale/method (ex. laser altimetry and stereo photogrammetry) and projected using model with climate
gridded data. However, extensive measurement without field-based validation has uncertainty
inherent with sensors. And information about behavior of debris-covered glacier is not enough forincorporating extensive model projection. Here we present detail investigation about recent massbalance of debris-covered type glacier of Lirung Glacier in Langtang Valley, Nepal Himalayas, fromelevation change by remotely sensed multi-temporal digital elevation models calibrated by fieldmeasurement and surface flow velocity by phase only correlation. Surface lowering (-1.3–-1.8 m a-1) are observed all over ablation area of Lirung Glacier. From mass balance calculation bycontinuity equation reveals it mainly caused by ablation. In upper ablation area, recent
accelerated decrease of emergence velocity (+0.3 and 0.0 m a-1 before and after 2000 respectively)
also contributes to the surface lowering. Energy mass balance model using gridded climate datasets
and weather observation. The calculated decrease of emergence velocity could caused by delayed
response to accumulation decreasing from 1980s to 1990s. In this context, upper ablation area will
accelerated downwasting due to positive feedback between surface lowering and flow velocity
decelerating.
Keywords: Himalaya, Glacier, DEM©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P08 -ACC20-P09

Japan Geoscience Union Meeting 2016

Ensemble forecast error covariance and correlation structures in coupled land-atmospheremodeling systems*kazuyoshi suzuki1, Milija Zupanski2, Dusanka Zupanski3, Taikan Oki4
1.Japan Agency for Marine-Earth Science and Technology, 2.Colorado State University, 3.Zupanski
Consulting LLC, 4.Institute of Industrial Science, The University of Tokyo
Coupled numerical models address interactions between processes in the atmosphere, ocean, land
surface, biosphere, chemistry, cryosphere, and hydrology. Including the interactions between suchprocesses can potentially extend the predictability and eventually help in reducing the uncertaintyof the prediction. Coupled data assimilation is a branch of data assimilation that deals withcoupled modeling systems. In this article the fundamentals of coupled data assimilation are firstdescribed through a mathematical example of a model including two coupled components. Then, througha series of single observation experiments, we analyze the forecast error covariance andcorrelation structures using the Maximum Likelihood Ensemble Filter (MLEF) data assimilation systemwith coupled atmosphere-land surface Weather Research and Forecasting (WRF) model . The atmospheric
WRF component has been coupled with two land surface models: Noah and Noah-MP. Two observation
locations with different precipitation regimes have been considered. Through this study, we foundthat error covariance and correlation were dependent on both location and land surface scheme. Snow
precipitation likely caused more complex structures in error covariances and correlations comparedto the precipitation-free site. The employment of a more realistic snow model was found to reduce
the error covariance and error correlation between the atmosphere and the soil in the coupledsystem. We also have demonstrated, for the first time in a data assimilation study, that
correlation structures can be useful in understanding the physical meaning of the forecast error
covariance and as a basis for selecting the most important forecast error covariance components forthe coupled data assimilation system. Overall, the complexity and structure of ensemble-based
forecast error covariance appears to be meaningful, which is encouraging for the futureapplications of coupled atmosphere –land surface data assimilation.
Keywords: Ensemble data assimilation, Snow model, Snow precipitation, Single observation experiment©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P09 -ACC20-P10

Japan Geoscience Union Meeting 2016

Differences of physical and chemical conditions between green and red algal snow appearedin mountain regions in Japan*Akane Watanabe1, Nozomu Takeuchi1, Sota Tanaka1, Tomomi Nakashima1, Kenshiro Miyauchi1
1.Graduate School of Science, Chiba University
Snow algae are photosynthetic microbes inhabiting alpine and polar snow fields. They usually bloom
on melting snow surface and change its color to green or red. The color of snow is determined by
pigment composition in the algal cells and is associated with taxa of algae, the stages of algal
life cycle, and/or response to the environment conditions. Green or red algal snow appears widely
in mountain regions in Japan. However, physical and chemical conditions of the appearance of green
or red algal snow is still unknown.
The purpose of this study is to describe the algal community and environment conditions of green
and red algal snow appeared in mountain regions in Japan. We collected the colored snow samples in
the melting season of 2015 in Mt. Gassan (green snow) in Yamagata prefecture and in Mt. Tateyama(red snow) in Toyama prefecture, Japan. We analyzed microscopic morphology and abundance of snow
algal cells, chlorophyll-a concentrations, absorption spectrum of their pigments, and soluble
chemical composition in the snow samples. Both green and red snow samples contained abundant snow
algal cells. The depth of the snow at the study sites was more than 120 cm. The vertical
distribution of algal cells in the snow pack showed that they were abundant at the surface layers.
There were significant differences in ammonium and phosphate concentrations in the surface snow
between green and red snows. This suggest that nutrient condition is one of the factors todetermine the color of algal snow.
Keywords: Snow algae, Mt. Gassan, Mt. Tateyama©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P10 -ACC20-P11

Japan Geoscience Union Meeting 2016

Chemical characteristics of glacial melt water in Tienshan Mountains in the central Asia
*YOICHIRO HORI1, Nozomu Takeuchi1, Zhongqin Li2
1.Chiba University Graduate School of Science, 2.Chinese Academy of Science
In arid or semi-arid regions of the central Asia, melt water from mountain glaciers has played an
important role as a water resource for the ecosystems and human societies in the regions. Althougha number of studies on contributions of melt water runoff to the local discharge have been
conducted in this regions, studies on influence of the melt water on chemical solutes in the
discharge is still limited. This study aims to describe the characteristics of the chemical solutesof the snow, ice, and meltwater on a glacier and of the downstream river and rain water in the Tian
Shan Mountains, China, and to discuss chemical processes of melt water on the glacier and river.
Fresh snow, old snow, surface ice, running meltwater on Urumqi No.1 Glacier, and water at theglacier terminus, and of the downstream river and rain water were collected in August 2015. Major
ions in the collected samples were analyzed with ion chromatography systems.
Results showed that most of chemical solutes were higher concentration in river water comparedwith those in snow, ice and the meltwater on the glacier. In particular, the concentrations of Mg2+
, Ca2+, SO42-, K+ in river water were approximately 6.5 to 19 times higher than those in snow or ice
on the glacier. The concentrations of Na+, Cl-, NO3- were 1.3 - 3.0 times higher in river watercompared with those of the glacier. In contrast, concentration of NH4+ was higher on snow andmeltwater on the glacier, but not detected in river water. These results show that the chemical
concentrations does not simply increase as water flow from glaciers to the downstream river, butthat chemical processes affecting the concentration are different among the solutes and areas of
the basin.
Keywords: biogeochemistry, mountains glacier, melt water©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P11 -ACC20-P12

Japan Geoscience Union Meeting 2016

Influence of snow characteristics on the water movement through the snow cover*Takehito Suzuki1, Satoru Yamaguchi2, Kouichi Nishimura1
1.Graduate School of Environmental Studies, Nagoya University, 2.Snow and Ice Research Center,
National Research Institute for Earth Science and Disaster Prevention
It is important to understand the water movement through the snow cover. However, the relationshipbetween the movement of water and snow characteristics is not known well, particularly, in an
unsaturated condition, since the process of water movement is so complicated.
In this study we carried out the experiment to reveal how the unsaturated hydraulic conductivity
changes with the snow characteristics and compared with the van Genuchten –Mualem model that is astandard model to describe the unsaturated hydraulic conductivity of soil.
Further, the water retention curve (WRC), which shows the relationship between the volumetric watercontent (θv) and the suction (h), was obtained with the gravity drainage column experiments, andthe effect of Black Carbon (BC) in the snow cover on WRC was examined.
Keywords: snow, water movement through snow cover, water retention curve©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P12 -ACC20-P13

Japan Geoscience Union Meeting 2016

Features of energy balance for snowmelt during rain-on-snow events in central Japan
Kazuki Katoh1, *Katsuhisa Kawashima2, Takane Matsumoto2, Tsutomu Iyobe3, Osamu Suzuki4, Akihiko
SASAKI5, Keisuke Suzuki5
1.Faculty of Science, Niigata University, 2.Research Institute for Natural Hazards and Disaster
Recovery, Niigata University, 3.Graduate School of Engineering, Kyoto University, 4.East Japan
Railway Company, 5.Faculty of Science, Shinshu University
It has been known that various kinds of hazards such as floods, landslides, avalanches can occur
during rain-on-snow (ROS) events due to large quantity of melt- and rainwater supplied to thesnowpack and the ground. Some previous studies have discussed the features of snowmelt during ROS
events based on field observations, however, the temporal and the spatial variations of snowmelt
during ROS events still have been poorly understood. For example, Marks et al. (1998) showed thatlarger heat source for melting was supplied to the snowpack during ROS events than non-ROS periodsin the Central Cascade Mountains in Oregon, USA, whereas Kojima et al. (1973) reported the result
showing less heat supply to the snowpack during ROS events in Moshiri basin in Hokkaido, Japan. In
this study, we analyzed meteorological data of Oshirakawa, Niigata Prefecture (360 m a.s.l.) fromthe melt season (from March 1 to the day when snowpack was disappeared) of 2012 to that of 2015 inorder to clarify the difference in the features of surface energy balance between ROS events (daily
rainfall > 10 mm) and non-ROS periods (the days without rainfall) and their temporal variations. In
addition, we also analyzed the meteorological data at Osado Mountains (800 m a.s.l.) in Niigata
Prefecture and at Mt. Ontakesan (2195 m a.s.l.) in Nagano prefecture during the melt season of 2015
to discuss the difference in surface energy balance during ROS events between a low-altitude basinand high-altitude mountains.
The result of the observations in Oshirakawa showed that, in average of the four years, less heatsource for snowmelt was supplied during ROS events than non-ROS periods due to less shortwave
radiation balance. However, the heat source for snowmelt during ROS events showed substantial
difference by year as a result of the changes in albedo and air temperature corresponding to thetime of occurrence of ROS events. In the high-altitude mountains, larger heat source for snowmelt
was supplied during ROS events than in the basin mainly due to larger turbulent heat fluxes
resulting from stronger winds. Thus, we can conclude that there is higher risk of snowmelt-induced
hazards in high-altitude mountains due to greater water supply into the the snowpack and theground.
Keywords: rain-on-snow event, snowmelt, energy balance©2016. Japan Geoscience Union. All Right Reserved.

- ACC20-P13 -