Susheel Adusumilli's research while affiliated with University of California, San Diego and other places

Publications (21)

Preprint
The Earth climate system is out of energy balance and heat has accumulated continuously over the past decades, warming the ocean, the land, the cryosphere and the atmosphere. According to the 6th Assessment Report of the Intergovernmental Panel on Climate Change, this planetary warming over multiple decades is human-driven and results in unpreceden...
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Plain Language Summary Surface melting over Antarctica's floating ice shelves is predicted to increase significantly during coming decades, but the implications for their stability are unknown. The Antarctic Peninsula has already seen meltwater driven ice shelf collapses. We are still learning how meltwater forms, flows and alters the surface, and...
Article
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In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and mo...
Article
Full-text available
In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and mo...
Article
Full-text available
Plain Language Summary Over a hundred gigatonnes of ice are being lost to the ocean from Antarctica each year, adding to ongoing sea level rise. Policymakers and stakeholders are interested in how much sea level rise will occur in the coming decades due to ice loss from Antarctica, but the range of values that scientists are providing is currently...
Article
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Human-induced atmospheric composition changes cause a radiative imbalance at the top of the atmosphere which is driving global warming. This Earth energy imbalance (EEI) is the most critical number defining the prospects for continued global warming and climate change. Understanding the heat gain of the Earth system – and particularly how much and...
Article
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Ocean-driven basal melting of Antarctica’s floating ice shelves accounts for about half of their mass loss in steady state, where gains in ice-shelf mass are balanced by losses. Ice-shelf thickness changes driven by varying basal melt rates modulate mass loss from the grounded ice sheet and its contribution to sea level, and the changing meltwater...
Article
Taking stock of our losses Earth's ice sheets are melting and sea levels are rising, so it behooves us to understand better which climate processes are responsible for how much of the mass loss. Smith et al. estimated grounded and floating ice mass change for the Greenland and Antarctic ice sheets from 2003 to 2019 using satellite laser altimetry d...
Preprint
Full-text available
Abstract. Human-induced atmospheric composition changes cause a radiative imbalance at the top-of-atmosphere which is driving global warming. This Earth Energy Imbalance (EEI) is a fundamental metric of climate change. Understanding the heat gain of the Earth system from this accumulated heat – and particularly how much and where the heat is distri...
Article
Full-text available
Plain Language Summary The Antarctic ice sheet is currently losing mass, but the causes for the mass loss remain unclear. It has been suggested that the reduction in the thickness of the floating ice shelves that surround the ice sheet, for example, due to ocean warming or changes in ocean circulation, may be responsible for some of the observed ic...
Article
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Increased climate variability is driving changes in water storage across the contiguous United States (CONUS). Observational estimates of these storage changes are important for validation of hydrological models and predicting future water availability. We estimate CONUS terrestrial water storage anomalies (TWSA) from 2007–2017 using Global Positio...
Article
The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) and its sole scientific instrument, the Advanced Topographic Laser Altimeter System (ATLAS), was launched on 15 September 2018 with a primary goal of measuring changes in the surface of the Earth's land ice (glaciers and ice sheets). ATLAS is a photon-counting laser altimeter, which records...
Article
Full-text available
In the version of this Article originally published, the word ‘from’ was incorrectly spelt as ‘form’ in Fig. 4b–d. In addition, the coloured scale bar was incorrectly labelled with a range of –1.5 to –1.5; this should have been –1.5 to +1.5. These errors have now been corrected in the online versions.
Article
Full-text available
In the version of this Article originally published, there was a spelling mistake in Figure 3 where ‘La Niña’ was incorrectly spelled ‘La Niño’. This has been corrected in all versions of the Article.
Article
Full-text available
Satellite observations over the past two decades have revealed increasing loss of grounded ice in West Antarctica, associated with floating ice shelves that have been thinning. Thinning reduces an ice-shelf's ability to restrain grounded-ice discharge, yet our understanding of the climate processes that drive mass changes is limited. Here, we use i...
Article
We have constructed 23-year (1994-2016) time series of Antarctic Peninsula (AP) ice-shelf height change using data from four satellite radar altimeters (ERS-1, ERS-2, Envisat, and CryoSat-2). Combining these time series with output from atmospheric and firn models, we partitioned the total height-change signal into contributions from varying surfac...
Article
We present a six-dimensional system describing coupled troposphere-stratosphere dynamics which takes the form of two coupled Lorenz-84 systems (one for each of the troposphere and stratosphere) involving thermal forcing terms. The systems are coupled through a linear interaction term, which permits energy transfer between both troposphere and strat...

Citations

... Satellite altimeters provide the main source of observation data to inform sea surface dynamics on a regional and global scale [9,1]. As illustrated in Fig.1, the associated daily sampling at sea surface on a global scale remains very scarce for current nadir altimeter constellations. ...
... As data from 2007 to 2020 were added for the updated plot (red line in Fig. 6), these periods of low UVI measurements are "filled in". For example, the deep and long-lasting ozone hole of 2020 [23] led to new UVI maxima on 24, 28, and 29 November. The UVI observed on 29 November 2020 was 12.0 and replaced the previous UVI maximum of this day of 8.0; an increase by 50%. ...
... Recently, ponding of meltwater on East Antarctic ice shelves has received considerable attention [135][136][137][138][139] , owing to its potential role in ice-shelf collapse through hydrofracturing 44,85,[140][141][142] . Surface meltwater (streams, lakes, slush), found in the grounding zone of numerous East Antarctic ice shelves 136 , indicates insufficient porosity for drainage into the firn. ...
... In this framework, radar altimetry and optical sensor measurements are the most promising source of data, although microwave data are sometimes used as well (Brakenridge et al., 2007;Huo et al., 2021). Altimetric data are widely used because of the direct relation between stage and river discharge (Abdalla et al., 2021;Belloni et al., 2021;Paris et al., 2016;Tourian et al., 2013;Zakharova et al., 2020), but the spatialtemporal sampling of the altimetry missions is currently a limitation, leading to the need of applying different strategies to densify the data (Tourian et al., 2016(Tourian et al., , 2017Boergens et al., 2017;Schwatke et al., 2015). As already demonstrated, if the altimetry is combined with other satellite information, the estimation of river flow is improved (see Tarpanelli et al., 2021 for a review). ...
... (Adusumilli et al., 2021). Most recently, Wille et al. (2021) used an AR detection algorithm to confirm that, while ARs only occur a few times per year along the Antarctic coastline, they contribute significantly to AIS snowfall especially in East Antarctica. ...
... size of the signal over a decade (Desbruyères et al., 2016). The ocean warming trend below 2,000 m accounts for ∼9% of the warming in the climate system from 1971 to 2018(von Schuckmann et al., 2020. Since warming of the climate system is a key metric for validating climate models (Hansen et al., 2011), better knowledge of how fast and where the ocean is warming is societally relevant. ...
... The growth and decay of polar ice sheets exert important controls on regional and global climate, while their future behaviour is a key uncertainty in predicting sea-level rise during and beyond this century 1 . Over the last decade, it has been observed that excess basal melting in Antarctica, arising from ocean heat supply, has increased the dynamic mass loss of grounded ice shelves bordering the Southern Ocean (SO) 2 . This observation has implications for future ice sheet stability, and also suggests that ocean warming may have played a role in controlling past ice sheet dynamics in Antarctica. ...
... Considering the continuous increase in atmospheric 10,11 and oceanic warming 12 , the present ice sheet extent may be lagging in its response to external forcing 13 . External atmospheric and oceanic forcing can drive thinning and recession of ice shelves, reduce buttressing, and accelerate upstream ice [14][15][16][17] , which could alter the grounded ice basal thermal state as it adjusts to these environmental changes. Additionally, internal ice thermo-frictional feedbacks could create instabilities causing frozen-bed regions within a few degrees below the PMP to spontaneously thaw [18][19][20][21] . ...
... Our sensitivity maps allow areas of greatest future vulnerability to be identified. Shepherd et al., 2018;Gudmundsson et al., 2019). ...
... The possible ties with the El Niño/Southern Oscillation (ENSO), which was the most well-known indicator of global interannual climate variability, was studied to better understand the climate drivers of hydrological changes in the YRB [34]. Version 2 of the ENSO index from 2002 to 2021 was adopted. ...