Global Cryosphere Watch (GCW), CryoNet Asia Workshop, Second Session Overview of in situ snow depth observations and data sources in Japan

Katsuhisa KAWASHIMA (Niigata University, Japan) [email protected] Tsutomu IYOBE (Kyoto University, Japan) [email protected]

2016012416JST Weather Home, Kochi Univ. | NICT | Himawari-8 VIS, JMA| Blue Marble, NASA Contents  Seasonal snow cover area in Japan Topography and development of snow clouds Snow depth distribution  Snow-depth observation in Japan Distribution of observation stations Density and altitudinal distribution of stations  Actual observation situation  Database location  Recent efforts of our group Quasi-real-time snow depth monitoring system Topography of Japan

Hokkaido

 Mostly rugged and mountainous area. (about 70% of the land in the 0 1000 2000 ≤ mountains above 300m) Elevation (m)  The Backbone Ranges extend 1200km north to south with altitudes above 1500m.  Distribution of snow depth is profoundly affected by topographical Honshu features. Shikoku Kyushu

500 0 500 1000 km Development of snow clouds

Much of snow deposit on the windward slopes of backbone ranges

northwest seasonal wind Dry & clear sky cold air mass heavy snowfalls west coast east coast Eurasian Warm water Backbone land mass (around 10 ℃) Ranges Sea of Japan Pacific Ocean Snow depth distribution in heavy snow winter

2006/02/06

Snowbelt along the Sea of Japan Snow-depth observation in Japan Organization Areal Number of Frequency Purpose Coverage Stations & Elevation Japan All over Japan 330 Every 10 Monitoring of Meteorological 0.5 – 1291m minutes or weather and climate Agency (JMA) hourly Ministry of Land, a) Dams 96 Hourly a) Water-resource Infrastructure, Basins 28 – 1566 m management Transport and b) Main roads 480 b) Road snow Tourism (MLIT) 0 – 2087 m removal Local government Local roads 1049 Hourly Road snow removal (Prefecture) 0 – 542 m Local government Settlements 173 Mainly daily Regional disaster (City) 3 – 345 m (generally at prevention (rescue, 9 a.m. local support of roof snow time) removal, etc.)

Research institute Mountainous 24 Every 10 Monitoring of & University areas 20 – 2190 m minutes or weather and hourly climate Distribution of observation stations

JWA MLIT MLIT (River) (Road)

Research Pref. City institute & University Distribution of observation stations

2,307 Stations 15 January 2016

0 500 1000 1500 2000 2500 m Elevation (m) Density of observation sites

Average coverage area of a site Density The Sea of Japan area (N/10km2) = 9.1 km2 / site 1 2 3 4 - 6 7 - 11

The Pacific area = 39 km2 / site Altitudinal distribution of observation stations Number of stations 800 Stations in the lowland area below 200 m account for 70 % 700 600 500 400 300 200

100 poor

0

50 100 200 300 400 500 600 700 800 900 1000 1500 2000 2500

< 50 <

< 100 <

< 800 < < 200 < 300 < 400 < 500 < 600 < 700 < 900 <

< 2,000 < < 1,000 < 1,500 < 2,500 < Altitude (m) Wind speed AMeDAS, JMA & direction

Automated Meteorological Data Sunshine Acquisition System, JMA duration

Air temperature Laser snow-depth sensor Precipitation Raod Weather Information System - Niigata Prefecture -

Antenna Air temperature

Ultrasonic snow-depth sensor Manual snow-depth observation - Ojiya City -

Snow stake Snow board Database location (JWA) Current data

Current snow depth data is available at http://www.jma.go.jp/jma/indexe.html Database location (JWA) Past data

Period selection Site selection Since around 1900 (*differ with the site) Elements selection (snow depth, snowfall, temperature, humidity, precipitation, wind speed & direction, etc) Download as CSV file

http://www.data.jma.go.jp/gmd/risk/obsdl/index.php Japanese only Database location (MLIT) Current and past data Water Information System http://www1.river.go.jp/

Search stations from the map Water Information System

yyyy/mm/dd time Snow depth (cm)

Japanese only Recent efforts of our group

・Our research group has developed “Quasi-real-time snow depth monitoring system” and started to collect automatically the real-time snow depth data all over Japan from Dec. 2015. ・Some of the information are provided via the web site.

(a) Display of the web site (b) Target of monitoring stations http://platform.nhdr.niigata-u.ac.jp/~snow-map/index.php?Newtoppage Information provision on the web site

Other information Regional maps

Daily snow

24-hour change

(a) Daily snow depth

vs. same day last year

(b) 24-hour change The latest information of snow depth maps using the observation data are displayed. Change of snow depth distribution from 20 Dec 2015 to 28 Jan 2016 *Animation He is mysterious.

One day, I tracked him in secret.

Thank you for your attention

He disappeared into another world.

Monitoring stations of snow water equivalent in Japan

Mt. Iwaki Fujisaki (1238m) (20m) Gassan-Shizu Shinjo (700m) (127m) Gassan-Ebigasawa (1150m) Myoko Sasagamine (1310m) Niigata Daisen Kagamiganaru (875m) Nishiyama-yakushi Nagaoka (320m) (97m) Tochio-Tashiro (423m) Okutadami- maruyama (1200m)

0 500 1000 1500 2000 2500 m Unonuma-Oimokawa (255m) SWE stations of Snow and Ice Research Center, NIED ・SWE measurements are made by 11 stations using the pressure-pillow meter Snow depth distribution in heavy snow winter

2006/02/06 HS (cm) 500

400

N) -

deg 300

200 Latitude(

100

1

132 134 136 138 140 142 144 Longitude (deg-E) Comparison of snow depth distribution in 2005/06 and 2006/07

2006/02/06 2007/02/16

Niigata Niigata