Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder

NSIDC Cryosphere Seminar

New insights into the polar sea ice-ocean state from NASA’s ICESat-2 presented by Alek Petty, NASA GSFC/UMD (

Abstract: NASA’s ICESat-2 laser altimetry mission is revolutionizing our understanding of the polar regions including its fast-changing sea ice cover. ICESat-2, launched in fall 2018, has been specially designed for advanced sea ice profiling due its combination of high resolution (<20 m), high precision (< 2 cm over flat surfaces) and dense (10 kHz, overlapping shots) along-track sampling across a novel 3 beam pair configuration – enabling us to accurately monitor small-scale freeboard variability across both polar oceans from space. ICESat-2 also benefits from dense polar coverage (profiling up to 88 degrees N/S) and has collected year-round data with minimal downtime since production started in October 2018. 

In this talk I present an overview of recent developments in profiling sea ice and polar ocean state variables from ICESat-2 (freeboard, thickness, floe size, sea surface height, wave activity) and on-going efforts to validate these data and reconcile them with estimates produced from other satellite datasets (e.g., CryoSat-2). I will also present the three winters of sea ice thickness estimates obtained by ICESat-2 since 2018 (with snow loading estimates provided by the NASA Eulerian Snow on Sea Ice Model) and a brief discussion of atmospheric drivers of these differences. 

Bio: Alek Petty is an Associate Research Scientist at NASA’s Goddard Space Flight Center (GSFC) and the University of Maryland; specializing in polar sea ice variability. Alek graduated with an M.Sci in Physics from the University of Bristol in 2010, and a PhD in Climate Science from University College London in 2014. His PhD research involved modeling the sea ice and ocean surrounding Antarctica. His postdoctoral studies extended this research approach to include the remote sensing of Arctic and Southern Ocean sea ice across scales. Alek's research approach now involves utilizing a combination of polar remote sensing data and models to improve our understanding of the polar regions and the wider climate system. More information can be found below and on his personal website:


Wednesday, November 17, 2021
11:00 am to 12:00 pm





  • CIRES employees
  • CU Boulder employees
  • General Public
  • NOAA employees
  • Science collaborators


  • Seminar
  • Open to Public



Mistia Zuckerman