Philipp S. Arndt

Philipp S. Arndt

he/him

I use satellite remote sensing and geospatial data analysis to produce actionable insights into how our planet is changing.

Posts by Collection

portfolio

publications

Detection of Multi-Level Hierarchies in Multi-View Cancer Networks, with Applications to Glioblastoma Multiforme

Published in Chalmers University of Technology Student Theses, 2018

In this master thesis, I propose a novel method that integrates multi-omics views of similarities between gene-associated sequencing data into a single network via a diffusion process, and detects communities on multiple levels of hierarchy. I apply this method to gene expression, copy number aberration and DNA methylation data from Glioblastoma Multiforme tumor samples to identify groups of genes that are highly co-regulated during disease progression. I verify that the resulting community structure is indeed representative of biological function by identifying various communities in which genes associated to known biological processes are highly overrepresented on statistically significant levels.

Recommended citation: Arndt, P. (2018). Detection of Multi-Level Hierarchies in Multi-View Cancer Networks, with Applications to Glioblastoma Multiforme [Masters Thesis]. https://fliphilipp.github.io/files/MScThesisPhilippArndt.pdf

Lethargic response to aerosol emissions in current climate models

Published in Geophysical Research Letters, 2018

Trends in downward solar radiation measured at ∼1,400 surface stations are presented for the last half century. Historical aerosol emissions support the idea that these observed radiation trends were mainly due to changes in atmospheric aerosol loading. CMIP5 simulations show negligible solar radiation trends over the same period, raising doubts about their ability to simulate future climate.

Recommended citation: Storelvmo, T., Heede, U. K., Leirvik, T., Phillips, P. C., Arndt, P., & Wild, M. (2018). Lethargic response to aerosol emissions in current climate models. Geophysical Research Letters, 45(18), 9814-9823. https://doi.org/10.1029/2018GL078298

ICESat-2 Meltwater Depth Estimates: Application to Surface Melt on Amery Ice Shelf, East Antarctica

Published in Geophysical Research Letters, 2021

ICESat-2 photons penetrate surface melt lakes and reflect from both the water surface and the underlying ice, providing depth estimates. We compared depths from eight algorithms (six ICESat-2 and two image-based) for four lakes present on Amery Ice Shelf in January 2019. Depths from ICESat-2 were more accurate than from imagery (30%–70% too low); merging these data will improve estimates ice-sheet wide.

Recommended citation: Fricker, H. A., Arndt, P., Brunt, K. M., Datta, R. T., Fair, Z., Jasinski, M. F., ... & Wouters, B. (2021). ICESat‐2 meltwater depth estimates: application to surface melt on amery ice shelf, East Antarctica. Geophysical Research Letters, 48(8), e2020GL090550. https://doi.org/10.1029/2020GL090550

Rapid Formation of an Ice Doline on Amery Ice Shelf, East Antarctica

Published in Geophysical Research Letters, 2021

Satellite images showed an \(11 \mathrm{\,km}^2\) depression on Amery Ice Shelf as an ice-covered lake drained abruptly in winter 2019 forming an ice doline. ICESat-2 and WorldView data show elevation fell as much as \(80 \mathrm{\,m}\) in the depression, amidst \(60 \mathrm{\,km}^2\) of hydrostatic rebound and uplift over \(36 \mathrm{\,m}\). ICESat-2 photon data profiled a new meltwater channel, incised when a lake formed by the flexural uplift overflowed into the doline in 2020.

Recommended citation: Warner, R. C., Fricker, H. A., Adusumilli, S., Arndt, P., Kingslake, J., & Spergel, J. J. (2021). Rapid formation of an ice doline on Amery Ice Shelf, East Antarctica. Geophysical Research Letters, 48(14), e2020GL091095. https://doi.org/10.1029/2020GL091095

A Framework for Automated Supraglacial Lake Detection and Depth Retrieval in ICESat-2 Photon Data Across the Greenland and Antarctic Ice Sheets

Published in The Cryosphere, 2024

In this paper, we present the Flat Lake and Underlying Ice Detection (FLUID) and Surface Removal and Robust Fit (SuRFF) algorithms which together provide a fully automated and scalable method for lake detection and depth determination from ICESat-2 ATL03 data, and establish a framework for its large-scale implementation using distributed high-throughput computing. We report FLUID/SuRFF algorithm performance over two regions known to have significant surface melt – Central West Greenland and Amery Ice Shelf catchment in East Antarctica – during two melt seasons. FLUID/SuRFF reveals a total of \(1249\) lakes up to \(25 \mathrm{\,m}\) deep, with more water during higher melt years.

Recommended citation: Arndt, P. S. and Fricker, H. A.: A framework for automated supraglacial lake detection and depth retrieval in ICESat-2 photon data across the Greenland and Antarctic ice sheets, The Cryosphere, 18, 5173–5206, 2024. https://doi.org/10.5194/tc-18-5173-2024

talks

We Skied Southern California To Show that Mountain Snowpack Can Be Measured from Space.

Published:

I gave a non-technical account of my ski-based ground validation campaign for evaluating the feasibility of space-based snowpack depth measurement with ICESat-2. This was given to private donors who had supported my PhD work, as part of the Scripps Fellowship Luncheon, and included a combination of an oral talk, a poster and a panel discussion.

Interactive Data Visualization with Open Altimetry & Contextualization of ICESat-2 Photon Data using Sentinel-2 Cloud Masking in Google Earth Engine.

Published:

As part of the 2023 UW eScience ICESat-2 Cloud Computing Hackweek Organizing Team, I developed and lead an interactive Jupyter-based tutorial on Contextualization of ICESat-2 Photon Data using Sentinel-2 Cloud Masking in Google Earth Engine, and helped developing tutorials on using ICESat-2 data for snow depth and shallow bathymetry retrievals. I also helped participants with any computing issues during the event, which was held from 7 to 11 August in Seattle.

Supraglacial Lakes across Greenland and Antarctica - New Insights from Five Years of ICESat-2 Meltwater Depth Measurements.

Published:

During the science team meeting of NASA’s ICESat-2 satellite altimetry mission, I presented preliminary results from aggregating five years of supraglacial melt lake depth measurements on the Greenland and Antarctic ice sheets. My lightning talk and poster were mostly based on an oral presentation I had given at the WAIS workshop the week before.

teaching

Resident Volunteer Teacher

Volunteer teaching, Trinity International Residential School - Tirunelveli, Tamil Nadu, India, 2012

I spent three months supporting Trinity International Residential School near Tirunelveli (Tamil Nadu, India) with ramping up their operations just after the school had opened in this rural part of southern India to allow local kids to receive an internationally accredited education. Duties included teaching several subjects, planning activities outside the classroom and helping out with anything else that needed attention around the school.

English Teacher

Volunteer teaching, Instituto Dois Irmãos / Two Brothers Foundation - Favela da Rocinha, Rio de Janeiro, Brazil, 2013

I spent three months living in Rocinha (the second largest favela in Brazil), and partnered with the Two Brothers Foundation to teach English to local kids, and helped with planning social activities.

SIO 115: Ice in the Climate System

Undergraduate course, University of California San Diego, Scripps Institution of Oceanography, 2020

I was the Teaching Assistant for SIO 115: Ice in the Climate System, taught by Prof. Helen Fricker during Winter 2020. The course examined the Earth’s cryosphere, including glaciers, ice sheets, ice caps, sea ice, lake ice, river ice, snow, and permafrost. We covered the important role of the cryosphere in the climate systems and its response to climate change.

SIO 199: Independent Research (Spring 2023)

Undergraduate course, University of California San Diego, Scripps Institution of Oceanography, 2023

I supervised two SIO 199: Independent Research undergraduate student projects for my advisor Prof. Helen Fricker. My main duties are providing research direction and technical support for data retrieval, cloud computing and analysis. The two resulting papers were titled “Morphology and Timing of a Recent Calving Event on Filchner-Ronne Ice Shelf” and “Characterizing Seasonal Fluctuations in Ice-Marginal Lake Levels in Northwestern Greenland”.

SIO 199: Independent Research (Spring 2024)

Undergraduate course, University of California San Diego, Scripps Institution of Oceanography, 2024

I am currently supervising the SIO 199: Independent Research undergraduate student project “Grounding Zone Dynamics at the Eastern Margin of the Amery Ice Shelf: Gillock Island and Kreitzer Glacier” for my advisor Prof. Helen Fricker. My main duties are providing research direction and technical support for data retrieval, cloud computing and analysis.

SIO 173: Dynamics of the Atmosphere and Climate

Undergraduate course, University of California San Diego, Scripps Institution of Oceanography, 2024

I am currently the Teaching Assistant for SIO 173: Dynamics of the Atmosphere and Climate, taught by Prof. Nick Lutsko. This class is an introduction to the dynamical principles governing the atmosphere and climate using observations, numerical models, and theory to understand atmospheric circulation, weather systems, severe storms, marine layer, Santa Ana winds, El Niño, climate variability, and other phenomena.