Lower Atmospheric Research using Unmanned Aerial System Facility (LARUS)

Objectives

Procurement of an Instrumented Aircraft System (IAS) as a national facility for airborne atmospheric research.
To make simultaneous measurements of aerosols, trace gases, cloud microphysics and large scale meteorological parameters at high temporal resolution and at different altitudes in different seasons over the Indian sub-continent.
To study cloud-aerosol interactions and the changes in precipitation processes over different parts of the Indian monsoon region.
To understand the interactions between clouds and large-scale environment using simultaneous measurements of clouds and large-scale meteorological parameters at high temporal resolution and using them in cloud resolving models.
Aerosol and radiative effects and aerosol-radiation closure studies. Parameterization schemes for monsoon clouds using aerosol, cloud microphysical and dynamical data generated.

About Us

With a strong emphasis on filling data gaps and meeting observational requirements for atmospheric process studies and models, IITM initiated the UAV project called “Lower Atmospheric Research using Unmanned Aerial System facility (LARUS)”, to obtain crucial, yet under-sampled, meteorological and various atmospheric observations in the lower atmosphere.
IITM is embarking on making detailed profiles of atmospheric boundary layer for various meteorological and atmospheric measurements using state-of-the-art instrumentation on UAV system which could descend to/ascend-from near the surface. This new initiative by IITM under the Ministry of Earth Sciences (MoES) aims to come up with India’s first ever Instrumented Unmanned Aerial vehicle (UAV) system for atmosphere and climate sciences.
It is envisaged that R & D activity under LARUS project will build roadmap for next generation of affordable observing capability for more sophisticated and challenging measurements for environmental sciences, ocean sciences, coastal studies (marine pollution), will also significantly ease monitoring of remote areas. This facility will also be used in air pollution assessment and associated impacts (health, visibility, climate).
This program developed under MoES will not only benefit the entire atmospheric sciences and climate research community but also, at its current rate, supports start-ups/small-business initiative/innovations such as the development of miniaturized instruments and suitable UAVs for atmosphere, climate, environment & ocean measurements.

Campaigns

LARUS Field campaign-1:

Research Test flights were conducted during March 2022 to demonstrate the performance of different sensors and data quality.

Project Details

Unmanned Aerial platforms will be utilized for in-situ airborne measurements to understand the atmospheric processes in the lower atmosphere. Fixed wing sophisticated UAV system with a maximum endurance of 3 to 4 hrs is integrated with state-of-the-art miniaturized scientific payload for various meteorological and atmospheric measurements. Miniaturized instrumentation for different important atmospheric parameters is explored for atmosphere and climate research studies.
This facility will boost basic research in the lower atmosphere for studying various atmospheric processes such as aerosol-radiation interactions, aerosol-cloud interactions, aerosol properties, atmospheric chemistry, thermodynamics of the lower atmosphere, aerosol-radiative feedback mechanisms associated with the climate variability and change over the Indian sub-continent. Such a facility will help to meet the challenges of the expanding subject and numerical models.

Back

Research Highlights

Cloud-induced enhanced solar irradiance (CES) – implications to renewable solar energy
During monsoon, the warming due to frequent CES events could locally offset a large cooling to some extent. Clouds resulting in huge irradiance variability in a day could also induce large fluctuations in renewable solar energy. Such short-term sporadic local events are averaged out in satellite data.
https://doi.org/10.1016/j.jastp.2022.105867
Inter annual crisscross pattern observed in South Asian monsoon rainfall and its relationship with aerosols
Monsoon rainfall follow a crisscross pattern with the positive and negative trends distinctly associated with aerosols. Different datasets confirm a hike in aerosol loading over South Asia except Northwest India which experienced a decrease. Mixed aerosol effects are found to be contributing to negative rainfall trends, however, less effective in positive trends.
https://doi.org/10.1016/j.atmosres.2022.106112
Did dust intrusion and lofting escalate the catastrophic widespread lightning on 16th April 2019, India?
Intense lightning activity accelerated due to dust entrainment into WD. Aerosol indirect effect is observed from multiple satellite observations. Evidence indicates dust boosting feedback loop led to catastrophic lightning.
https://doi.org/10.1016/j.atmosres.2021.105933
Diurnal (24 h) cycle and seasonal variability of cloud fraction retrieved from a Whole Sky Imager over a complex terrain in the Western Ghats and comparison with MODIS
CF time series (24 h) over a complex terrain of WG using IR Sky Imager. CF diurnal cycle in WG shows huge variability in all seasons except in monsoon. Day CF is higher than night CF in post-monsoon and winter seasons. Small scale events get averaged out on diurnal, monthly and seasonal scales. Large bias is observed between ground-based and MODIS diurnal and seasonal CF.
https://doi.org/10.1016/j.atmosres.2020.105180
Spatiotemporal variability and evolution of day and night winter fog over the Indo Gangetic Basin using INSAT-3D and comparison with surface visibility and aerosol optical depth
INSAT-3D depicted spatiotemporal evolution of fog continuously for day and night. INSAT-3D fog and surface visibility exhibited a good relationship. Wide spread fog envelopes IGB for long duration at midnight and early morning hours. Fog/smog onset is triggered by high pollution level and stable atmosphere in winter. Central and west IGB are most vulnerable to frequent dense fog/smog events.
https://doi.org/10.1016/j.scitotenv.2020.140962
System driven changes in aerosol-cloud interactions and its impact on the life-cycle of a monsoon depression
Role of aerosol-cloud interactions in the initial growth of monsoon depression is investigated using airborne observations in an idealistic high aerosol scenario. Initial suppression of the MD intensity due to aerosol indirect effects. Revitalized MD intensity with increased moisture supply part of the mesoscale convection. Aerosols under humid conditions cause suppression and redistribution of rainfall associated with MD over Central India. A positive effect of Giant Cloud Condensation Nuclei (GCCN) could be dominating the negative effect of smaller CCN near the oceanic regions.
https://doi.org/10.1016/j.atmosres.2019.104765
High temporal variability of wintertime fog, aerosol and Red-Blue-Ratio using ground-based observations of shortwave irradiance and sky imagery over a station in Indo-Gangetic Basin: Optical and Radiative characteristics
A new approach is explored to retrieve day time fog using high frequency ground-based SW irradiance and sky imagery. Results showed high temporal variability of winter fog, aerosol and RBR. RBR distinguishes the sky condition from clear-haze-fog/cloud. High values of Fog Optical Depth (FOD) reveal intense and prolonged events during day time. SW radiative forcing due to fog and aerosol increased with increase in optical depths.
https://doi.org/10.1016/j.atmosenv.2020.117382

Back

Recent Publications

Mahesh Nikam, Sanket Kalgutkar and Padmakumari B. "In-house built a portable mini Radiosonde Ground Receiver (mRGR) System for meteorological data telemetry from higher altitudes", Technical Report No. TR-07, ESSO/IITM/ART/TR/01(2023)/201
Padmakumari B, Sanket Kalgutkar, Sneha Sunil, Mahesh Nikam, G. Pandithurai, High temporal variability of surface solar irradiance due to cloud enhancement effect over the Western Ghat mountains in peninsular India, Journal of Atmospheric and Solar-Terrestrial Physics, 232, June 2022, https://doi.org/10.1016/j.jastp.2022.105867
Raja B., Maheskumar R.S., Padmakumari B., Sunitha Devi S., Interannual crisscross pattern observed in South Asian monsoon rainfall and its relationship with aerosols, Atmospheric Research, 271: 106112, June 2022, DOI:10.1016/j.atmosres.2022.106112, 1-10
Shukla B.P., John J., Padmakumari B., Das D., Thirugnanasambantham D., Gairola R.M., Did dust intrusion and lofting escalate the catastrophic widespread lightning on 16th April 2019, India?, Atmospheric Research, 266: 105933, March 2022, DOI:10.1016/j.atmosres.2021.105933, 1-13
Maheskumar R. S., Padmakumari B., Savita Morwal, JR Kulkarni. Role of topography and aerosols in the rainfall over the Western Ghats and rain shadow regions as inferred from aircraft measurements. VayuMandal 47(2), 86-95, 2021.
Sunil S., Padmakumari B., Pandithurai G., Patil R.D., Naidu C.V., Diurnal (24 h) cycle and seasonal variability of cloud fraction retrieved from a Whole Sky Imager over a complex terrain in the Western Ghats and comparison with MODIS, Atmospheric Research, 248: 105180, January 2021, DOI:10.1016/j.atmosres.2020.105180, 1-13

Back

Achievements

IITM introduces India’s first ever ' Instrumented Unmanned Aerial Vehicle (UAV) system' with a state-of-the-art scientific payload for atmosphere and climate studies.
https://twitter.com/moesgoi/status/1534084741925785600?s=20&t=1GnDfkPWC_6M18NcxeeG5w
1st BVLOS research test flight conducted using fixed-wing medium category UAV with approvals from MoCA and AAI.

Back