Painter, Thomas: Jet Propulsion Laboratory (Project Lead)
Project Funding:
2016 - 2019
NRA: 2016 NASA: Utilization of Airborne Visible/Infrared Imaging Spectrometer- Next Generation Data from an Airborne Campaign in India-AVRSNG
Funded by NASA
Abstract:
Himalayan glacier retreat is commonly attributed to global warming, but air temperature and BC only began to increase appreciably about 40 years ago, whereas widespread increases in dust loading to the Himalaya in the last 150 years have coincided with the sustained glacier retreat in the Himalaya. Recent in situ measurements, ice cores, and modeling of aerosol transport and radiative forcing in the Himalaya suggest that snow darkening, earlier exposure of darker glacier ice owing to more rapid snowmelt, and atmospheric heating from dust and black carbon (BC) may have at-surface radiative forcings 1 to 2 orders of magnitude stronger than total greenhouse gas forcings. This evidence leads us to understand that this critical region is changing due to a complex mix of forcings beyond just radiative forcing from increases in greenhouse gases (GHG). To explore this complex mix, we work under the overarching science goal of: quantitatively understanding physical processes that drive changes in the snow and ice of High Mountain Asia.The extreme topographic variation of the Himachal Pradesh, Indian Himalaya drives variation in energy fluxes. The flights provided by the ISRO-NASA AVIRIS-NG program over India allow us to uniquely and rigorously address three crucial scientific and technical/ retrieval questions in the Western Himalaya:Q1. How do imaging spectroscopy retrievals of snow properties in complex terrain vary between opographically corrected HDRF and apparent surface HDRF? Q2. How do snow grain size, radiative forcing by impurities in snow, and snow albedo vary across the extreme topographic gradients of the Indian Himalaya? Q3. How can a fusion of spectroscopy data with more frequent and broader coverage from multispectral sensors enable characterization of the snow properties and radiative forcing over larger areas and across seasons and years? To specifically address these science questions, we will pursue the following project objectives: O1. Perform topographic and atmospheric correction of AV-NG spectral radiances to surface spectral HDRF and compare against delivered AV-NG apparent surface reflectance. (Question 1) O2. Analyze spatial variability of snow grain size, radiative forcing by dust/BC, and snow albedo across all AVIRIS-NG imaged regions in the Himachal Pradesh. (Question 2) O3. Validate SIHPS snow property retrievals with in-situ measurements made by the Center for Snow and Avalanche StudyEstablishment (SASE) O4. Fuse quantitative imaging spectroscopy retrievals for Himachal Pradesh to enhance semi-quantitative retrievals from multispectral MODIS, VIIRS, and Landsat OLI data for greater spatial and temporal coverage. This investigation directly addresses the requirements expressed in the NASA A.31 solicitation Utilization of AVIRIS-NG Data from an Airborne Campaign in India, by providing analyses of the spatial variability of the spectral albedo of snow and ice and relationships with snow properties and presence of absorbing impurities. The PI and the team have the expertise and extensive experience with imaging spectroscopy of snow properties, snow hydrology of high mountain systems, energy and mass balance of snow and ice, and multispectral satellite remote sensing. The investigation is synergistic with existing and planned NASA missions. The most relevant mission concept being explored in the context of the Earth Science Decadal Survey is the Hyperspectral Infrared Imager (HyspIRI). The imaging spectrometer component of HyspIRI will image snow and ice around the globe and offers the capacity for quantitative retrievals with uncertainties low enough to address the specific questions of changes in snow properties relative to greenhouse gas warming.
More details may be found in the following project profile(s):
