A P Dimri

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Verified

A P verified their affiliation via an institutional email.

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• PhD
• Director at Indian Institute of Geomagnetism

Adaptation is increasingly important for regions around the world where large changes in climate could have an impact on populations and industry. The Brahmaputra-Ganges catchments have a large population, a main industry of agriculture and a growing hydro-power industry, making the region susceptible to changes in the Indian Summer Monsoon, annual...

An attempt is made to integrate subgrid scale scheme on the work of Dimri and Ganju (Pure Appl Geophys 167:1–24, 2007) to understand the overall nature of surface heterogeneity and landuse variability along with resolvable finescale micro/meso scale circulation over the Himalayan region, which is having different altitudes and orientations causing...

A nonhydrostatic version of Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Mesoscale Model (MM5) is used to study the effects of the horizontal model resolution and orography while simulating an active western disturbance (WD) that affected northwest India from 21 to 25 January 1999. Two numerical experiments are...

Cyclonic storms associated with the mid-latitude Subtropical Westerly Jet (SWJ), referred to as Western Disturbances (WDs), play a critical role in the meteorology of the Indian subcontinent. WDs embedded in the southward propagating SWJ produce extreme precipitation over northern India and are further enhanced over the Himalayas due to orographic...

Analysis of regional climate simulations to evaluate the ability of 11 Coordinated Regional Climate Downscaling Experiment in South Asia experiments (CORDEX-South Asia) along with their ensemble to produce precipitation from June to September (JJAS) over the Himalayan region have been carried out. These suite of 11 combinations come from 6 regional...

Satellite Traces (STs) are the important ionogram signatures for the presence of upwellings in the bottom‐side ionosphere, which provide the necessary seed perturbation for the development of equatorial plasma bubbles (EPBs). In this study, a virtual ionosonde experiment is simulated to investigate the various ST signatures under the presence of sh...

Understanding the Earth's magnetic field through regional records of secular variation is essential for deciphering its short-term behaviour. This study presents an archaeomagnetic and rock-magnetic investigation of archaeological artefacts from Vadnagar, Gujarat, and introduces India's first continuous palaeosecular variation (PSV) curve for the l...

The current study explores how the topside equatorial and low‐latitude ionosphere responded to the super geomagnetic storm on 10–11 May 2024, using in situ data from the Swarm constellation. During the storm's main phase, enhancements in the EIA (equatorial ionization anomaly) were observed, forming strong super‐fountains. The EIAs were extended to...

A unique two-dimensional gridded geomagnetic map of India is constructed using the geomagnetic field observations from 11 observatories of India, operated by the Indian Institute of Geomagnetism. In order to create the spatial grid, 11 spatial techniques are compared with observed magnetic field during 2011–2020. Out of the 11 known techniques of s...

Climate change is increasing the likelihood of severe storms. Attribution of any such single event on climate change is difficult, but warming has increased evaporation, intensifying the droughts and frequency of heavy rainfall or snowfall events. The decrease in temperature gradients and hence corresponding potential over different regions has cha...

Climate change poses a significant threat to the lives and livelihoods of local communities in the Himalayan regions. These regions do not have an extensive network of meteorological stations due to poor infrastructure for climate change studies. Understanding how the local community perceives climate change provides an important insight into speci...

Performance of the latest high-resolution COordinated Regional Climate Downscaling EXperiment-Coordinated Output for Regional Evaluation (CORDEX-CORE) model experiment suites for simulating temperature over Northeast India (NEI) during 1979-2005 are assessed. Three different suites of Regional Climate Models (RCMs), i.e., COSMO, RegCM4.7 and REMO s...

Western disturbances (WDs) are synoptic-scale weather systems embedded within the subtropical westerly jet. Manifesting as upper-level troughs often associated with a lower-tropospheric low over western or northern India, they share some dynamical features with extratropical cyclones. WDs are most common during the boreal winter (December to March)...

Over the past decades, the estimation of changes in climate and energy mass balance of Earth’s surface has become crucial. The Himalayas, in the South Asian region, are highly vulnerable to precipitation and hydrological/hydrometeorological balance/change. It will significantly affect freshwater availability and the associated sectors of these habi...

The Himalayas are a region of geomagnetic importance, as they impact the geomagnetic field of Earth and space weather, as it is one of the largest mountain belts in the world. Due to its huge mass, it may influence the dynamics of the Earth’s core, the primary source of the geomagnetic field. In Indian longitudes, the mean location of the solar qui...

This is the first statistical ground investigation of unique low latitude Spectral Resonance Structures (SRS) that increase beyond 5Hz $5\,Hz$, crossing the fundamental Schumann resonance at few occurrences. The study is carried out using high resolution magnetic field variation data obtained from induction coil magnetometer (ICM) installed at very...

One of the most intense geomagnetic storms of recent times occurred on 10–11 May 2024. With a peak negative excursion of Sym‐H below −500 nT, this storm is the second largest of the space era. Solar wind energy transferred through radiation and mass coupling affected the entire Geospace. Our study revealed that the dayside magnetopause was compress...

The Indus River Basin (IRB), one of the major river basins in the Hindu Kush Himalaya, is primarily sustained by meltwater from the cryosphere. It caters to diverse sectors, including intense irrigation-supported agriculture, energy production, tourism and biodiversity. The cryosphere of the Upper Indus Basin (UIB) is mainly influenced by the weste...

Western Himalayas (WH) receives precipitation through eastward propagating synoptic weather systems, Western Disturbances (WDs), embedded in large scale subtropical westerly jet (SWJ) during Northern Hemispheric boreal winter (December, January and February; DJF). In the recent decade, WDs have undergone certain changes in their characteristic’s vi...

A preliminary lithospheric magnetic anomaly map of the Indian subcontinent (LAMI-1) was generated utilising seven years (April 2014–December 2020) of data recorded by the Swarm satellite constellation. To obtain a high-resolution lithospheric anomaly map, the fields originating from sources other than lithospheric sources are eliminated sequentiall...

Dykes are one of the primary subvolcanic bodies that transport magma from the shallow magma chamber or from the deep-seated magma reservoir. The mechanism of magma transport and emplacement in dyke swarms can contribute precious details on source and how magma has associated with crustal rocks. Here we are presenting the results obtained from the A...

This study uses Mars Atmosphere and Volatile EvolutioN observations of electron density and magnetic field for a period of four Martian years (MYs 33–36) (∼8 Earth years) to investigate the effects of Martian crustal magnetic fields on the distribution and variability of Mars' ionosphere. The results show a clear enhancement in electron density in...

The Equatorial Electrojet (EEJ) is one of the important near‐earth space weather phenomena which exhibits significant diurnal, seasonal and solar activity variations. This paper investigates the EEJ variations at diurnal, seasonal and solar cycle time scales from the Indian sector and portrays a new empirical EEJ field model developed using the obs...

Earth's average air temperature is warming at a substantial rate leading to an increase in the frequency and severity of extremes with major environmental and socioeconomic impacts. The present study discusses temperature and precipitation extremes in Kashmir Valley using observational data from six meteorological stations. An Expert Team on Climat...

Interplanetary (IP) shocks are one of the dominant solar wind structures that can significantly impact the Geospace when impinge on the Earth's magnetosphere. IP shocks severely distort the magnetosphere and induce dramatic changes in the magnetospheric currents, often leading to large disturbances in the geomagnetic field. Sudden enhancements in t...

Air pollution impacts on human health are of serious concern in northern India, and over the Delhi National Capital Region (NCR) in particular. The Kharif crop residue burning (CRB) is often blamed for degradation of Delhi-NCR’s seasonal air quality. However, the concentration of fine particulate matter (PM2.5) remained stable in Delhi, while the f...

This brief presents an intriguing aspect of the physico-chemical interactions among particulate matters (PM2.5; PM10) and several gases pollutants during pre- (01 March to 24 March 2020) and COVID-19 first phase of lockdown period (25 March to 30 April 2020) over Delhi-National Capital Region. In order to see the impact of lockdown on ambient parti...

The current study explores the relationship between solar variability and tropical cyclone (TC) activity using sunspot number (SSN) and TC best‐track data as respective proxies. We have considered six regions of the globe, for example, EP: Eastern Pacific, NA: North Atlantic, NI: North Indian, SI: South Indian, SP: South Pacific, and WP: Western Pa...

The study inspects the elevation dependency of temperature and precipitation across northeast India. Various gridded observations and outputs from high-resolution Regional Climate Models under the CORDEX-CORE framework have been employed. The better representation of the topography leads to higher orographic precipitation in the model environment....

We report F-region airglow imaging of fossil plasma depletions around midnight that revived afresh under persisting thermospheric gravity wave (GW) activity. An all-sky imager recorded these events in OI 630 nm imaging over Ranchi (23.3° N, 85.3° E; mlat. ∼19° N), India, on 16 April 2012. Northward-propagating and east–west-aligned GWs (λ∼210 km, v...

The future state of the global water cycle and prediction of freshwater availability for humans around the world remain among the challenges of climate research and are relevant to several United Nations Sustainable Development Goals. The Global Precipitation EXperiment (GPEX) takes on the challenge of improving the prediction of precipitation quan...

Himalaya – one of the pristine and ecologically fragile mountain ecosystem is highly vulnerable to any small changes in climatic system. Under changing climate conditions, assessing regional trends become more important owing to dependence of more than 1 billion people on Himalayas. To analyze the climatic trends and magnitude, this study utilized...

The study presents detailed meteorological characteristics of extremely severe cyclonic storm (ESCS) Fani, and subsequent Atmospheric Gravity Waves (AGWs) induced D‐region ionospheric perturbations and the role of lightning activity in it. The cyclone shaped as a weak disturbance over the north Indian Ocean (2.7°N, 89.7°E) on 25 April 2019. The dis...

Western disturbances (WDs) are synoptic-scale weather systems embedded within the subtropical westerly jet. Manifesting as upper-level troughs often associated with a lower-tropospheric low over Western India, they share some dynamical features with extratropical cyclones. WDs are most common during the boreal winter (December to March), during whi...

Upper Indus Basin (UIB), being climatologically sensitive and socio-economically important, has emerged as a hotspot for eco-hydrological studies. Permafrost, one of the essential components of the regional hydrological cycle with a critical role in microclimate, is also an important water resource in the UIB. Despite being an important componen...

Forecasting Indian Summer Monsoon Rainfall (ISMR) is a formidable task due to its intricate variability. This study harnesses the power of machine learning (ML) to decipher the chaotic trajectory within ISMR, drawing inspiration from ML's success in predicting analogous systems. By utilizing ERA-interim data, the method dissects ISMR's chaotic natu...

This study investigates the trend in the projected rainfall and temperature over undivided Sudan and its major cities of political, trade, and agricultural significance under two different Representative Concentration Pathways (RCPs; RCP2.6 and RCP8.5). Available high-resolution datasets from the Coordinated Regional Climate Downscaling Experiment-...

High‐resolution Sr and Nd isotope compositions along with major and trace element abundances have been analyzed in silicate fraction of sediments core, SSD004‐GC03, from the Equatorial Indian Ocean (7.2°N and 77.9°E) at 1,540 m water depth with a depositional history of ∼38 ka to determine source variabilities and their controlling factors. ⁸⁷Sr/⁸⁶...

Cryosphere all over the globe is thawing, be it the Arctic, Antarctic, Greenland or Himalaya. Studies have predicted that loss in the glacier mass over the Upper Indus Basin in Kashmir Himalaya would amount to 47 to 67% (Romshoo in 7th conference of Science and Geopolitics of Arctic and Antarctic, 2023). A similar trend prevails in the Bhaga basin...

Indian work in Antarctica has covered mainly atmosphere, biology and geoscience domains of sciences in central Dronning Maud land and Princess Elizabeth land (PEL) of eastern Antarctica. While observations of synoptic weather, geophysical and glaciological parameters have continued in both the sectors, thematic earth science studies focusing on cru...

In recent decades, the hydrological balance/budget over Himalayan river basins has imperatively become crucial for decision-making in flood risk, water resource management, identifying water-sensitive areas etc. In the present study, assessment of the abating total water storage (TWS) in the three river basins viz. Indus (IRB), Ganga (GRB) and Brah...

The present work serves as a theoretical commentary over the Himalayan Re-gridded and Observational EXperiment (HiROX) and distributes the conceived framework grown under the two-phase experiment. HiROX is a scientific effort aimed at revising the existing precipitation knowledge over the Central Himalayas over the state of Uttarakhand, including t...

This paper releases two regional precipitation products produced in the Himalayan Re-gridded and Observational Experiment (HiROX) conducted over the Central (Uttarakhand) Himalayas including the Upper Ganga Basin. The distributed precipitation products cover a period of about 70 yrs: HiROX-1 ranges from 1972 to 2018 (47 yrs) and is a regridded stat...

The Asian summer monsoon is one of the active synoptic scale weather phenomena, and has significant socioeconomic implications. A vast population relies on the associated precipitation, mostly dominating the agricultural practices of the region. Therefore, it is essential to assess past behavior to understand the present, including future projectio...

For assessing the impact of climate change on socio-eco-hydrological systems at the catchment scale, reasonable and reliable meteorological input data are essential. The modelled, gridded meteorological datasets of several fields, e.g., precipitation, temperature, surface moisture, etc. from Regional Climate Models (RCMs) are widely used as inputs...

Interplanetary (IP) shocks are known to cause significant modifications in Earth's magnetospheric and ionospheric current systems. The sudden enhancement of solar wind dynamic pressure (PDyn) associated with IP shocks could induce convection electric fields at high‐latitude ionosphere which can promptly penetrate to equatorial and low‐latitude regi...

The boundary layer plays a vital role in governing the local atmospheric dynamics and meteorology, including the vertical transport of moisture, momentum, energy, and air pollutants. Hence, accurate parameterization of the boundary layer processes is essential in atmospheric models such as the regional climate models (RCMs). However, evaluations of...

The present study compares two different modelling suites such as Coordinated Regional Climate Downscaling Experiment-South Asia (CORDEX-SA) and Coordinated Regional Climate Downscaling Experiment-Coordinated Output for Regional Evaluation (CORDEX-CORE) to represent ISM rainfall (ISMR) over India and monsoon core zone (MCZ) and examine for the subs...

The linkage between elevation and precipitation in the mountainous regions across the world including the Indian Himalayan Region (IHR) is very complex. Various meteorological parameters, viz., albedo, shortwave and longwave radiations, humidity, and mass-energy balance, play a major role in the physical processes occurring in these places. The pre...

Remotely sensed topo-climatic factors, potential incoming solar radiation (PISR), land surface temperature (LST), topographic wetness index (TWI), Surface emissivity, and elevation, and machine learning techniques are used for mapping the spatial distribution of permafrost in the Tso Kar, a sub-basin of Upper Indus Basin (UIB) in Leh, Ladakh (UT)....

Exposure to particulate matter less than 2.5 µm in diameter (PM2.5) is a cause of concern in cities and major emission regions of northern India. An intensive field campaign involving the states of Punjab, Haryana and Delhi national capital region (NCR) was conducted in 2022 using 29 Compact and Useful PM2.5 Instrument with Gas sensors (CUPI-Gs). C...

Recent advancements of space geodetic observations and remote sensing techniques allow to extract hydrological information reasonably well at the river basin scale. Combining this information with in-situ data provide a new opportunity to explore the feasibility of assessing hydrological models at the basin scale. Appreciating such possibilities, a...

Climate change differentially influences the frozen ground, a major dynamic component of the cryosphere, on a local and regional scale. Under the warming climate with pronounced effects reported at higher altitudes, the characterization of the frozen ground is very important in the Upper Indus Basin (UIB), an important and critical region wit...

The Chir-Pine (Pinusroxburghii) and Banj-Oak (Quercus leucotrichophora)-dominated ecosystems of central Himalaya provide significant green services. However, responses of these ecosystems, with respect to ecosystem carbon flux variability, to changing microclimate are not yet studied. Since quantification of ecosystem responses to fluctuation in th...

While studying the Western Disturbances (WDs) and associated precipitation forming mechanism in changing time, we found that there is significant amount of precipitation received during Non-WDs days too. In addition, it is also highlighted that all the WDs don’t precipitate. And hence cumulative winter precipitation is kind of summation of all the...

Nutmeg is an important spice and contributes significantly to the gross domestic product of Indonesia. The study examines the impact of climate change on Indonesia and the production of nutmeg over Banda Neira Island. For this, the outputs from high‐resolution regional climate models under different representative concentration pathways (RCP2.6, RC...

The Asian Precipitation Experiment (AsiaPEX) was initiated in 2019 to understand terrestrial precipitation over diverse hydroclimatological conditions for improved predictions, disaster reduction, and sustainable development across Asia under the framework of the Global Hydroclimatology Panel (GHP)/Global Energy and Water Exchanges (GEWEX). AsiaPEX...

Permafrost in the Upper Indus Basin (UIB) in Ladakh, India, is a critical water source and is less studied. Identifying permafrost and its characteristics is a crucial knowledge gap in the UIB. Thus, understanding the permafrost active layer dynamics is critical and essential due to its implications on regional hydrology, infrastructure stability,...

Background In Uttarakhand, a state in northern India, forest fire events increased from 922 in 2002 to 41,600 in 2019, influencing forest structure and function. In the literature, it has been reported that, globally, climate change influences the intensity and expansion of forest fire events. However, with regard to Uttarakhand, studies on the rel...

In this study, the performance of the latest high-resolution CORDEX-CORE model simulations is assessed with respect to the corresponding gridded Indian Meteorological Department (IMD) and ERA5 observations in representing the monsoon rainfall over northeast India during the historical period (1979–2005). Three different RCM model simulations (COSMO...

The Indus is one of three largest river systems emerging from the Hindu-Kush Himalaya (HKH). In the Upper Indus Basin (UIB), water resources, agriculture and livelihoods are highly vulnerable to climate change induced hazards and risks. Present study investigates impacts of climate change on water availability, agriculture and livelihoods based on...

Western Disturbances (WDs) are the primary contributor of winter precipitation over the Western Himalayas (WH). The precipitation falling as snow is essential for Himalayan glaciers accumulation, contributing to Himalayan rivers supporting downstream population of the Indian subcontinent. Climate change has affected the Himalayas, which is noticeab...

Predicting the impacts of future climate on food and fibre production are essential for devising suitable adaptations strategy. This study aims to understand the impact of climate change on cotton crop change using Regional Climate Model (RCM) in the near and far future. The RCM model considered for the study is RegCM4 from CORDEX-SA experiment for...

The present work studies a severe smog event that occurred in Delhi (India) in 2017, targeting the characterization of PM2.5 and its deposition potential in human respiratory tract of different population groups in which the PM2.5 levels raised from 124.0 µg/m3 (pre-smog period) to 717.2 µg/m3 (during smog period). Higher concentration of elements...

The present study investigated the long-term inter-annual, seasonal, and monthly trend analysis and variability of PM2.5 at different time scales over the national capital, Delhi, India using high-resolution surface observations from six stations during 2007 - 2021. The non-parametric Mann- endall and Theil-Sen slope estimator were used to study th...

Summary: The Upper Indus Basin (UIB) is an extraordinarily significant social-ecological system that supports hundreds of millions of people. Water resources in the UIB are extremely vulnerable due to climate change, and as a result of historic lack of demand management. New knowledge, based on interdisciplinary and transdisciplinary research is...

Various studies reported an elevation dependent precipitation and temperature changes in mountainous regions of the world including the Himalayas. Various mechanisms are proposed to link the possible dependence of the precipitation and temperature on elevation with other variables, including, long-and shortwave radiation, albedo, clouds, humidity,...