THE SMALL EARTH NEPAL

Date: 16 October 2017

Venue: Central Department of Hydrology and Meteorology (CDHM)/ Tribhuvan University

Organizers: The Small Earth Nepal, Central Department of Hydrology and Meteorology/Tribhuvan University and Department of Meteorology/Trichandra Multiple Campus

Presenters:

Dr. Chris DeBeer, the Network and Science Manager for the Changing Cold Regions Network (CCRN), Global Water Future (GWF), and International Network for Alpine Research Catchment Hydrology (INARCH).

Presentation title- “Observation, understanding and prediction of climate and environmental change in cold and mountainous regions – research initiatives in western Canada and their global relevance”

Prof. Toru Terao, Faculty of Education, Kagawa University, Japan.

Presentation title- “Direct Validation of TRMM/PR near Surface Rain over the Northeastern Indian Subcontinent Using a Tipping Bucket Raingauge Network”

Global warming and other climatic changes are causing rapid and widespread changes to the landscape, cryosphere, vegetation, and water cycling.  Cold regions, such as high latitudes and high elevation alpine regions are at the forefront of this change and are highly sensitive to further warming.  There is therefore an urgent need to understand the nature of the changes and to develop the improved modelling tools needed to manage uncertain futures.  The Global Institute for Water Security and the Centre for Hydrology at the University of Saskatchewan in Saskatoon, Canada are leading several major national and international initiatives dealing with these issues and focusing primarily on Canada and its cold western interior region in particular.  This is a region that exemplifies many of the scientific and societal issues faced in many other similar parts of the world, and where impacts have global-scale consequences.

Chris DeBeer, the Network and Science Manager for Changing Cold Regions Network (CCRN), Global Water Futures (GWF), and International Network for Alpine Research Catchment Hydrology (INARCH), will introduce these projects and describe some of the ongoing activities and research initiatives, beginning with an overview of the past and future projected Earth system changes in western Canada.  In the past two decades, and even the most recent several years alone, the region has experienced record setting extremes varying from severe drought and extreme wildfire, to devastating flooding, with extensive damages and high costs to society.

Similarly, Prof. Toru Terao, Faculty of Education, Kagawa University, Japan, will talk about his recently published paper entitled “Direct Validation of TRMM/PR Near Surface Rain over the Northeastern Indian Subcontinent Using a Tipping Bucket Raingauge Network”. He will further introduce his ongoing research activities. The near surface rain (NSR) dataset of the Tropical Rainfall Measurement Mission (TRMM) Precipitation Radar (PR) 2A25 V7 was validated using 36 tipping bucket raingauges installed over the northeastern Indian subcontinent, which correspond with the rain center of the Asian summer monsoon. This raingauge network covers the Brahmaputra flood plains and mountainous areas, including the Meghalaya Plateau, which is one of the wettest places in the world. We analyzed data from 2004 to 2013, and obtained 28,207 TRMM/PR-raingauge matchups with 2,170 TRMM/PR rainy fields of views. Using them, we detected a reasonable time lag of around 300 seconds between the estimates from the TRMM/PR NSR and raingauges. Significant and large underestimations of TRMM/PR NSR were detected during the monsoon season (June–September) over the large areas of Meghalaya, Sylhet, and Barak. The bias ratios were −51.3% and −35.2% for the Meghalaya and Sylhet-Barak areas, respectively. In the Meghalaya subregion, major contribution to underestimation came from moderate TRMM/PR NSR from stratiform systems, and missed detection error was secondary contributor. In Sylhet-Barak subregion, moderate TRMM/PR NSR from convective systems largely contributed. Underestimation was not detected in premonsoon season (March–May).

Note: Participation by invitation only.