Research Interests:
The great Himalayas, the world’s highest mountain system, is home to millions of people and hundreds of unique species. It has one of the world's largest concentrations of cryospheric components (glaciers, snow, and permafrost). The... more
The great Himalayas, the world’s highest mountain system, is home to millions of people and hundreds of unique species. It has one of the world's largest concentrations of cryospheric components (glaciers, snow, and permafrost). The Himalayas supply continued meltwater to some of Asia’s greatest river systems and play a vital role in the South Asian monsoon environment by guarding theIndian subcontinent from the dry, cold air masses of central Asia and blocking the warm, moist airflow from the Indian Ocean. Unfortunately, this water tower has been experiencing rapid changes driven by climate change in recent decades. Changes in this region have had and will continue to have major negative consequences for people living in the area and globally. However, changes in the climate extremes and their consequences have not been understood well yet because of the extreme topography that hinders the establishment and maintenance of monitoring networks. We will introduce some outstanding ongoing research activities in understanding key processes and changes in high-mountain meteorology, climate extremes, and glacier evolution over the southern slopes of the Himalayas. Results suggest that elevation-dependent warming accompanied by rapid glacier retreat is accelerating in the region. In addition, climate extremes are likely to increase with intensifying drought and floods.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The study was conducted using rainfall time-series data for 42 years from 1977 to 2018. We have identified seven large monsoon deficient years. Among these years, 1992, 2009, and 2015 consisted of El Niño episodes which quantify... more
The study was conducted using rainfall time-series data for 42 years from 1977 to 2018. We have identified seven large monsoon deficient years. Among these years, 1992, 2009, and 2015 consisted of El Niño episodes which quantify significant rainfall deficits 19.29, 13.6, and 17.59 % respectively from an average rainfall. With some exceptions, all El Niño years observed deficit rainfall. On El Niño years averaged deficit rainfall was approximately nine percent below than the average monsoon rainfall. The eastern region observed the large deficient monsoon years frequently than the central and western regions of Nepal. The central region recorded large spatial variability of average summer rainfall ranging from less than 200 mm/months in lesser Himalayans to more than 3,000 mm/months in mid-mountainous region. The western region had observed a large deficient summer monsoon anomaly 45 % in the year 1979. Similarly, the central region had 31 % deficient summer monsoon anomalies in 1992...
Research Interests:
Research Interests:
The great Himalayas, the world’s highest mountain system, is home to millions of people and hundreds of unique species. It has one of the world's largest concentrations of cryospheric components (glaciers, snow, and permafrost). The... more
The great Himalayas, the world’s highest mountain system, is home to millions of people and hundreds of unique species. It has one of the world's largest concentrations of cryospheric components (glaciers, snow, and permafrost). The Himalayas supply continued meltwater to some of Asia’s greatest river systems and play a vital role in the South Asian monsoon environment by guarding theIndian subcontinent from the dry, cold air masses of central Asia and blocking the warm, moist airflow from the Indian Ocean. Unfortunately, this water tower has been experiencing rapid changes driven by climate change in recent decades. Changes in this region have had and will continue to have major negative consequences for people living in the area and globally. However, changes in the climate extremes and their consequences have not been understood well yet because of the extreme topography that hinders the establishment and maintenance of monitoring networks. We will introduce some outstanding ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Climatology and Monsoon
Research Interests:
This study is aimed at evaluating the impacts of climate change (CC) on the water-energy-economics-continuum considering a storage type hydroelectricity project (STP). Inflows from ensembled CC scenarios for two RCPs (4.5 and 8.5) and... more
This study is aimed at evaluating the impacts of climate change (CC) on the water-energy-economics-continuum considering a storage type hydroelectricity project (STP). Inflows from ensembled CC scenarios for two RCPs (4.5 and 8.5) and three time-windows (near-future, mid-future, far-future) until the end of this century, generated from an earlier study by the same team, was used for the analysis. The proposed 1200 MW Budhigandaki Hydropower Project in Nepal is taken as a case. A set of reservoir operating rules were derived considering the baseline data which was then used to generate future energy and revenue at the monthly, seasonal and annual timescales. Results show that future annual energy is expected to increase by about 9–13% from the baseline. Furthermore, future revenue generation is projected to increase in the range of 20–28 million USD annually. This overall gain in the revenue due to additional energy generation is an anticipated positive impact of CC which is capable of contributing to the reduction of greenhouse gases and minimizing fossil-fuel laden trade deficit. This study recommends that: STPs with the provision of flexible operating rules are desirable for climate resiliency in hydroelectricity; areas expected to witness decreased future hydroelectricity generation need to explore other alternative sources of renewable energy; and the policy instruments pertaining to the financial aspects of hydroelectricity should be continuously updated considering future conditions.
Research Interests:
As the highest mountain on Earth, Mount Everest is an iconic peak that offers an unrivalled natural platform for measuring ongoing climate change across the full elevation range of Asia’s water towers. However, Everest’s extreme... more
As the highest mountain on Earth, Mount Everest is an iconic peak that offers an unrivalled natural platform for measuring ongoing climate change across the full elevation range of Asia’s water towers. However, Everest’s extreme environment challenges data collection, particularly on the mountain’s upper slopes, where glaciers accumulate mass and mountaineers are most exposed. Weather stations have operated on Everest before, including the world’s previous highest, but coverage has been sparse in space and time. Here we describe the installation of a network of five automatic weather stations (AWSs), including the two highest stations on Earth (8,430 and 7,945 m MSL) which greatly improves monitoring of this iconic mountain. We highlight sample applications of the new data, including an initial assessment of surface energy fluxes at Camp II (6,464 m MSL) and the South Col (7,945 m MSL), which suggest melt occurs at both sites, despite persistently below-freezing air temperatures. Th...
Research Interests:
Lentil is a leading pulse crop of Nepal. It is also a high value crop, having an immense potentiality of export to other countries. Although Nepal Agricultural Research Council (NARC) has recommended ten varieties and improved production... more
Lentil is a leading pulse crop of Nepal. It is also a high value crop, having an immense potentiality of export to other countries. Although Nepal Agricultural Research Council (NARC) has recommended ten varieties and improved production technologies of lentil, the adoption at farmer's field has been low due to which the average yield is far below its attainable yield. Poor access to improved seeds, technical knowledge and services among farmers, and lack of appropriate market intervention are major shortcomings to develop this sector commercially. So, to enhance the productivity and production of lentil and to improve linkages among the value chain actors, FORWARD Nepal implemented the project on commercial farming of lentil in 11 terai districts of Nepal in 2011/12 and 2012/13. The project introduced a technology package consisting of improved varieties, rhizobium inoculation, seed priming and basal application of fertilizer diammonium phosphate (DAP) on a cost share basis wit...
Research Interests:
DOI: 10.3126/bodhi.v2i1.2865 Bodhi Vol.2(1) 2008 p.89-116
Research Interests:
Research Interests:
Research Interests:
The cloudburst event occurred on 19-20 July 1993, creating a devastating flash flood over south-central Nepal. The storm killed hundreds of people, and damaged millions of dollars of properties. This study focused on the synoptic and... more
The cloudburst event occurred on 19-20 July 1993, creating a devastating flash flood over south-central Nepal. The storm killed hundreds of people, and damaged millions of dollars of properties. This study focused on the synoptic and thermodynamics that triggered the cloudburst in central Nepal, bringing 540 mm of rainfall over a small region in less than 24 hours. Moreover, it investigates the primary reason for the particular extremest event in Nepal. Our results show the strong upward motion transported the significant moisture that led to favorable condition for development of thick cloud cover, producing a record-breaking precipitation during that event over central Nepal. Likewise, the monsoon trough with negative sea level pressure anomaly over central Nepal located east of the upper-level trough further suggests a westward tilt with height in the disturbances associated with cloudburst on the event day. Further, we also simulate the extreme precipitation events over the regi...
Research Interests:
The predictability of the weather on Mount Everest’s upper slopes can be a matter of life or death for those trying to climb the world’s highest mountain, yet the performance of forecasts has been almost unknown due to a lack of surface... more
The predictability of the weather on Mount Everest’s upper slopes can be a matter of life or death for those trying to climb the world’s highest mountain, yet the performance of forecasts has been almost unknown due to a lack of surface observations. The extent to which climate change may be affecting this iconic location is also uncertain for the same reason. To address this data limitation, the National Geographic and Rolex Perpetual Planet Expedition installed the world’s highest weather station network (reaching within 420 m of the summit) on the Nepal side of Mount Everest in 2019. Its observations have already generated considerable advances in understanding the meteorological environment on the mountain’s upper slopes, but the network was compromised by damage to the highest stations in recent years. Here, we describe the expedition that upgraded the network and took it to new heights, focusing on the installation at the Bishop Rock (8,810 m MSL), just below the summit. Almos...
Research Interests:
Research Interests:
Research Interests:
The frequency of winter drought episodes marked frequently in the recent decade. This study examined the time series indices of drought variability over Nepal using historical data of 42-years (1977–2018) for 107 stations using... more
The frequency of winter drought episodes marked frequently in the recent decade. This study examined the time series indices of drought variability over Nepal using historical data of 42-years (1977–2018) for 107 stations using Standardized Precipitation Index (SPI). Monthly rainfall was used as input variable to generate the output for SPI time scales of each station. SPI threshold was used to identify severity, frequency, duration, and spatial extent of the drought episodes. The SPI3 output showed occurrence of major eight drought episodes. Among these years, dryness signals identified the worst drought episode in the year 2006. However, in regional prospective the western region observed extreme drought episode in 2009. There was distinct drought dynamics in each major drought event over the western, central and eastern Nepal. Spatial variability for SPI3 time scale was interpolated to depict spatial patterns of major drought episodes with their severities. The areas of Nepal aff...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
This study identified summer and annual drought events using the Standard Precipitation Index (SPI) for 107 stations across Nepal from 1977 to 2018. For this, frequency, duration, and severity of drought events were investigated. The SPI4... more
This study identified summer and annual drought events using the Standard Precipitation Index (SPI) for 107 stations across Nepal from 1977 to 2018. For this, frequency, duration, and severity of drought events were investigated. The SPI4 and SPI12 time scales were interpolated to illustrate the spatial patterns of major drought episodes and their severity. A total of 13 and 24 percent of stations over the country showed a significant decreasing trend for SPI4 and SPI12. Droughts were recorded during El Niño and non-El Niño years in Nepal. Among them, 1992 was the worst drought year, followed by the drought year, 2015. More than 44 percent of the locations in the country were occupied under drought conditions during these extreme drought events. Droughts have been recorded more frequently in Nepal since 2005. The areas of Nepal affected by extreme, severe, and moderate drought in summer were 8, 9, and 18 percent, while during annual events they were 7, 11, and 17 percent, respective...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Daily flow data from 1964 to 2015 of Budhigandaki River at Arughat were analyzed to assess the impact of flow variation at different time scales to the run of the river (RoR) type of hydropower projects. The data show very high... more
Daily flow data from 1964 to 2015 of Budhigandaki River at Arughat were analyzed to assess the impact of flow variation at different time scales to the run of the river (RoR) type of hydropower projects. The data show very high inter-annual variation in daily, monthly and seasonal flows. The long term annual average flow at Arughat was 160 m3/s and varies from 120 to 210 m3/s. The long-term averages of loss in flow for both dry and wet seasons based on daily flows for three design discharges (Q90, Q60 and Q40) were found to be respectively -0.72, -1.76 and -1.54 m3/s for dry season and 0.0, -0.27 and -2.26 m3/s for wet season. Although long-term average loss is small, uncertainty increases with the increase in design discharge. The long-term dry season power loss is about 3 % for the RoR projects of the basin however, its annual variation is large. There is a probability of losing the quantum of energy generation by nearly 40% in some years and gaining by about 30 % in some other y...
Research Interests:
Research Interests:
This paper reports analytical review results on the global and national importance of solar energy as a clean and renewable source of energy. Pre-monsoon and post monsoon seasons have higher mean monthly sunshine duration (about 8... more
This paper reports analytical review results on the global and national importance of solar energy as a clean and renewable source of energy. Pre-monsoon and post monsoon seasons have higher mean monthly sunshine duration (about 8 hours/day) than summer (about 5 hours/day) and winter (about 7 hours/day) seasons in Kathmandu. The lowest sunshine duration during summer season is attributed to the effect of monsoonal clouds during that period. Pre-monsoon and monsoon seasons receive solar energy of about 250 W/m2 and 200 W/m2 respectively. The winter season receives the least amount of solar radiation (about 150 W/m2). Results show high prospect of solar energy utilization both in rural and urban areas of Nepal.
Research Interests:
Airborne measurements of aerosol particles and cloud microstructures were made over the ocean around the south of Kyushu Islands of Japan during the Asian Atmospheric Particulate Environmental Change Experiment 3/Asia Pacific Regional... more
Airborne measurements of aerosol particles and cloud microstructures were made over the ocean around the south of Kyushu Islands of Japan during the Asian Atmospheric Particulate Environmental Change Experiment 3/Asia Pacific Regional Aerosol Characterization Experiment (APEX-E3/ACE-Asia) during the period of 17 March to 13 April 2003. Results demonstrated that polluted air from the Asia continent could penetrate several hundreds of kilometers over the oceans and clouds forming in that air had significantly altered microphysical properties. Based on the number concentration of aerosol particles with diameters between 0.3 and 5 μm, two cases were investigated: 22 March 2003 was termed a "clean" case and 12 April 2003 as a "polluted" case. Single particle analysis of particles was also carried out by electron microscopy. The particles in the polluted marine boundary layer were characterized by the presence of sulfate particles with traces of potassium and heavy met...