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Research Interests

My research interests are in the use of satellite and airborne remote sensing techniques, integrated with in situ observations and modeling, to understand how and why the Earth's ice cover is changing, and what those changes mean for life on Earth. In particular, my research focuses on the contributions of ice sheets and high-latitude glaciers to sea level rise and their relationship to the changing climate. Toward that end, I have been heavily involved in the development of NASA's Ice Cloud and land Elevation Satellite (ICESat) and its successor, ICESat-II, and I have worked on cryospheric applications of various other satellites and aircraft instruments. Most of my research is supported by NASA, where I worked as a scientist for 12 years, before joining CIRES. In 2011, I returned to NASA on a two-year assignment as the agency’s Chief Scientist, serving as principal adviser to the NASA Administrator on NASA scienceprograms, strategic planning, and the evaluation of related investments.

Current Research

Using satellites and in situ measurements to study polar ice, my group works with space-based, airborne, and in situ observations to study changes in Earth’s glaciers and ice sheets, with a focus on three areas. The first is the development of methods for determining how much meltwater is stored in—and subsequently lost from—melt lakes on the surface of the Greenland ice sheet. This meltwater has significant implications for the speed at which the ice sheet flows toward the sea because the meltwater can reduce friction between the ice and the bedrock on which it rests and also changes the deformation properties of the ice as the warm meltwater penetrates into the ice.

We have produced the first-ever detailed and validated maps of supraglacial lake volumes from high-resolution imagery across a large region in Greenland, producing a critical tool for understanding the ice sheet’s hydrology and its contributions to sea level rise. The second research area has focused on understanding the nature of compaction of the near-surface firn (snow) on the Greenland ice sheet to improve the interpretation of satellite and aircraft altimetry observations of ice-sheet-thickness changes. Compaction measurements from stations we installed on the ice sheet surface in 2013 have shown that local melt in summer 2013 released large amounts of latent heat into the firn over several months following the end of the melt season, increasing annual compaction rates by 8 percent.

This seemingly small change during this year of modest melt has a very large impact on converting elevation changes to mass changes, and our ability to quantify it represents a significant step forward in addressing the largest uncertainty component of altimetry-derived sea level contributions from Greenland. Finally, we combine data from NASA’s Gravity Recovery and Climate Experiment (GRACE), Ice Cloud and land Elevation Satellite (ICESat), and other missions to assess the spatial distribution of mass loss from the Greenland Ice Sheet, its peripheral glaciers and ice caps, and the Canadian ice caps with unprecedented detail at 26-kilometer spatial resolution (see figure). These areas of research are fundamental to our ultimate overarching objective of determining how and why Earth’s glaciers and ice sheets are changing and what those changes mean for life on Earth.

More Info

I received my MS in Aerospace Engineering Sciences and Ph.D. in Geography from the University of Colorado in 1991 and 1996 respectively. From 1996 through 2008, I worked in various positions at NASA, ranging from a research scientist, to program manager, to head of NASA Goddard Space Flight Center's Cryospheric Sciences Branch.  In 2008, I had the good fortune of being able to return "home" to serve as director of the Earth Science and Observation Center at CU and join the faculty of the Geography Department.   I am very glad to have the opportunity to bring the experiences and perspectives that I have acquired during my tenure at NASA back to the academic environment.  I believe that when students can see the practical value of what they are learning, they are more motivated and the concepts resonate more effectively.  My hope is that the perspective I can bring to the classroom will enable me to provide a unique learning opportunity for the students by infusing real-world experience into the concepts I am teaching them.

Recent Courses Taught

• Fall 2023 GEOG 2271 Introduction to the Arctic Environment
• Spring 2019  GEOG 4110/5100 Special Topics: Advanced Remote Sensing

Honors and Awards

• Selected to serve as NASA Chief Scientist, 2011–2012
• NASA GSFC Center Director’s Team Recognition Award, 2007
• American Institute of Aeronautics and Astronaustics Space Systems Award, 2006
• National Aeronautics and Space Administration Exceptional Service Medal, 2004
• NASA Group Achievement Award, ICESat Science Team, 2004
• NASA Office of Earth Science Award, 2003
• NASA Group Achievement Award, Honor Award Team 2003
• NASA Office of Earth Science Terra Peer Award, 2002
• NASA Office of Earth Science Award, 2002
• NASA Office of Earth Science Award, 2001
• Presidential Early Career Award for Scientists and Engineers, 1999
• Tau Beta Pi National Engineering Honor Society (since 1985)

Publications

• Colgan, W, H Rajaram, W Abdalati, C McCutchan, R Mottram, MS Moussavi and S Grigsby (2016),  Rev. Geophys. Version: 1 54 (1) 119-161, issn: 8755-1209, ids: DK1RE, 
• Moussavi, Mahsa S., Waleed Abdalati, Allen Pope, Ted Scambos, Marco Tedesco, Michael MacFerrin and Shane Grigsby (2016), Derivation and validation of supraglacial lake volumes on the Greenland Ice Sheet from high-resolution satellite imagery. Version: 1 REMOTE SENSING OF ENVIRONMENT 183 294-303, issn: 0034-4257, 
• Colgan, W, W Abdalati, M Citterio, B Csatho, X Fettweis, S Luthcke, G Moholdt, SB Simonsen and M Stober (2015), Hybrid glacier Inventory, Gravimetry and Altimetry (HIGA) mass balance product for Greenland and the Canadian Arctic. Remote Sens. Environ. Version: 1 168 24-39, issn: 0034-4257, ids: CR5SY, 
• Colgan, W, A Sommers, H Rajaram, W Abdalati and J Frahm (2015), Considering thermal-viscous collapse of the Greenland ice sheet. Earth's Future Version: 1 3 (7) 252-267, issn: 2328-4277, ids: CP5DT, 
• Moussavi, MS, W Abdalati, T Scambos and A Neuenschwander (2014), Applicability of an automatic surface detection approach to micropulse photon-counting lidar altimetry data: implications for canopy height retrieval from future ICESat-2 data. Int. J. Remote Sens. Version: 1 35 (13) 5263-5279, issn: 0143-1161, ids: AM8EU, 
• McGrath, D, K Steffen, PR Holland, T Scambos, H Rajaram, W Abdalati and E Rignot (2014), The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica. J. Geophys. Res.-Earth Surf. Version: 1 119 (3) 588-602, issn: 2169-9003, ids: AE9WR, 
• Arendt, A, S Luthcke, A Gardner, S O'Neel, D Hill, G Moholdt and W Abdalati (2013), Analysis of a GRACE global mascon solution for Gulf of Alaska glaciers. J. Glaciol. Version: 1 59 (217) 913-924, issn: 0022-1430, ids: 231AK, 
• Colgan, W, S Luthcke, W Abdalati and M Citterio (2013), Constraining GRACE-derived cryosphere-attributed signal to irregularly shaped ice-covered areas. Cryosphere Version: 1 7 (6) 1901-1914, issn: 1994-0416, ids: 273OY, 
• Painter, TH, MG Flanner, G Kaser, B Marzeion, RA VanCuren and W Abdalati (2013), End of the Little Ice Age in the Alps forced by industrial black carbon. Proc. Natl. Acad. Sci. U. S. A. Version: 1 110 (38) 15216-15221, issn: 0027-8424, ids: 219GW, , 
• Phillips, T, H Rajaram, W Colgan, K Steffen and W Abdalati (2013), Evaluation of cryo-hydrologic warming as an explanation for increased ice velocities in the wet snow zone, Sermeq Avannarleq, West Greenland. J. Geophys. Res.-Earth Surf. Version: 1 118 (3) 1241-1256, issn: 2169-9003, ids: 238VC, 
• Colgan, W, WT Pfeffer, H Rajaram, W Abdalati and J Balog (2012), Monte Carlo ice flow modeling projects a new stable configuration for Columbia Glacier, Alaska, c. 2020. Cryosphere Version: 1 6 (6) 1395-1409, issn: 1994-0416, ids: 059IV, 
• Colgan, W, H Rajaram, RS Anderson, K Steffen, HJ Zwally, T Phillips and W Abdalati (2012), The annual glaciohydrology cycle in the ablation zone of the Greenland ice sheet: Part 2. Observed and modeled ice flow. J. Glaciol. Version: 1 58 (207) 51-64, issn: 0022-1430, ids: 898QV, 
• Liang, YL, W Colgan, Q Lv, K Steffen, W Abdalati, J Stroeve, D Gallaher and N Bayou (2012), A decadal investigation of supraglacial lakes in West Greenland using a fully automatic detection and tracking algorithm.Remote Sens. Environ. Version: 1 123 127-138, issn: 0034-4257, ids: 016CX, 
• McGrath, D, K Steffen, H Rajaram, T Scambos, W Abdalati and E Rignot (2012), Basal crevasses on the Larsen C Ice Shelf, Antarctica: Implications for meltwater ponding and hydrofracture. Geophys. Res. Lett. Version: 1 39, Art. No. L16504, issn: 0094-8276, ids: 999JZ, 
• Phillips, T, S Leyk, H Rajaram, W Colgan, W Abdalati, D McGrath and K Steffen (2011), Modeling moulin distribution on Sermeq Avannarleq glacier using ASTER and WorldView imagery and fuzzy set theory. Remote Sens. Environ. Version: 1 115 (9) 2292-2301, issn: 0034-4257, ids: 788ZZ, 
• Colgan, W, H Rajaram, R Anderson, K Steffen, T Phillips, I Joughin, HJ Zwally and W Abdalati (2011), The annual glaciohydrology cycle in the ablation zone of the Greenland ice sheet: Part 1. Hydrology model. J. Glaciol.Version: 1 57 (204) 697-709, issn: 0022-1430, ids: 822BT
• Colgan, W, K Steffen, WS McLamb, W Abdalati, H Rajaram, R Motyka, T Phillips and R Anderson (2011), An increase in crevasse extent, West Greenland: Hydrologic implications. Geophys. Res. Lett. Version: 1 38 , Art. No. L18502, issn: 0094-8276, ids: 823PQ, 
• Abdalati, W, HJ Zwally, R Bindschadler, B Csatho, SL Farrell, HA Fricker, D Harding, R Kwok, M Lefsky, T Markus, A Marshak, T Neumann, S Palm, B Schutz, B Smith, J Spinhirne and C Webb (2010), The ICESat-2 Laser Altimetry Mission. Proc. IEEE Version: 1 98 (5) 735-751, issn: 0018-9219, ids: 593WQ, 
• Joughin, I, BE Smith and W Abdalati (2010), Glaciological advances made with interferometric synthetic aperture radar. J. Glaciol. Version: 1 56 (200) 1026-1042, issn: 0022-1430, ids: 818KP
• Arendt, AA, SB Luthcke, CF Larsen, W Abdalati, WB Krabill and MJ Beedle (2008), Validation of high-resolution GRACE mascon estimates of glacier mass changes in the St Elias Mountains, Alaska, USA, using aircraft laser altimetry. J. Glaciol. Version: 1 54 (188) 778-787, issn: 0022-1430, ids: 416WS
• Tedesco, M, W Abdalati and HJ Zwally (2007), Persistent surface snowmelt over Antarctica (1987-2006) from 19.35 GHz brightness temperatures.Geophys. Res. Lett. Version: 1 34 (18) , Art. No. L18504, issn: 0094-8276, ids: 213RG, 
• Luthcke, SB, HJ Zwally, W Abdalati, DD Rowlands, RD Ray, RS Nerem, FG Lemoine, JJ McCarthy and DS Chinn (2006), Recent Greenland ice mass loss by drainage system from satellite gravity observations. ScienceVersion: 1 314 (5803) 1286-1289, issn: 0036-8075, ids: 108BR, , 
• Jacka, TH, W Abdalati, I Allison, F Carsey, G Casassa, M Fily, M Frezzotti, HA Fricker, C Genthon, I Goodwin, Z Guo, GS Hamilton, RCA Hindmarsh, CL Hulbe, TH Jacka, KC Jezek, TA Scambos, C Shuman, P Skvarca, S Takahashi, RSW van de Wal, DG Vaughan, WL Wang, RC Warner, DJ Wingham, NW Young and HJ Zwally (2004), Recommendations for the collection and synthesis of Antarctic Ice Sheet mass balance data. Global Planet ChangeVersion: 1 42 (4-Jan) 1-15, issn: 0921-8181, ids: 845ID, 
• Krabill, W, E Hanna, P Huybrechts, W Abdalati, J Cappelen, B Csatho, E Frederick, S Manizade, C Martin, J Sonntag, R Swift, R Thomas and J Yungel (2004), Greenland Ice Sheet: Increased coastal thinning. Geophys. Res. Lett. Version: 1 31 (24) , Art. No. L24402, issn: 0094-8276, ids: 885BY, 
• Abdalati, W, W Krabill, E Frederick, S Manizade, C Martin, J Sonntag, R Swift, R Thomas, J Yungel and R Koerner (2004), Elevation changes of ice caps in the Canadian Arctic Archipelago. J. Geophys. Res.-Earth Surf. Version: 1 109 (F4) , Art. No. F04007, issn: 0148-0227, ids: 875DS, 
• Joughin, I, W Abdalati and M Fahnestock (2004), Large fluctuations in speed on Greenland's Jakobshavn Isbrae glacier. Nature Version: 1 432 (7017) 608-610, issn: 0028-0836, ids: 875PL, 
• Thomas, RH, W Abdalati, E Frederick, WB Krabill, S Manizade and K Steffen (2003), Investigation of surface melting and dynamic thinning on Jakobshavn Isbrae, Greenland. J. Glaciol. Version: 1 49 (165) 231-239, issn: 0022-1430, ids: 771DW, 
• Zwally, HJ, W Abdalati, T Herring, K Larson, J Saba and K Steffen (2002), Surface melt-induced acceleration of Greenland ice-sheet flow. ScienceVersion: 1 297 (5579) 218-222, issn: 0036-8075, ids: 571UT, , 
• Abdalati, W, W Krabill, E Frederick, S Manizade, C Martin, J Sonntag, R Swift, R Thomas, W Wright and J Yungel (2002), Airborne laser altimetry mapping of the Greenland ice sheet: application to mass balance assessment. J. Geodyn. Version: 1 34 (4-Mar) 391-403, issn: 0264-3707, ids: 602BK, 
• Krabill, WB, W Abdalati, EB Frederick, SS Manizade, CF Martin, JG Sonntag, RN Swift, RH Thomas and JG Yungel (2002), Aircraft laser altimetry measurement of elevation changes of the greenland ice sheet: technique and accuracy assessment. J. Geodyn. Version: 1 34 (4-Mar) 357-376, issn: 0264-3707, ids: 602BK, 
• Zwally, HJ, B Schutz, W Abdalati, J Abshire, C Bentley, A Brenner, J Bufton, J Dezio, D Hancock, D Harding, T Herring, B Minster, K Quinn, S Palm, J Spinhirne and R Thomas (2002), ICESat's laser measurements of polar ice, atmosphere, ocean, and land. J. Geodyn. Version: 1 34 (4-Mar) 405-445, issn: 0264-3707, ids: 602BK, 
• Abdalati, W and K Steffen (2001), Greenland ice sheet melt extent: 1979-1999. J. Geophys. Res.-Atmos. Version: 1 106 (D24) 33983-33988, issn: 2169-897X, ids: 522DE, 
• Fahnestock, M, W Abdalati, I Joughin, J Brozena and P Gogineni (2001), High geothermal heat row, basal melt, and the origin of rapid ice how in central Greenland. Science Version: 1 294 (5550) 2338-2342, issn: 0036-8075, ids: 503TT, 
• Fahnestock, M, W Abdalati, S Luo and S Gogineni (2001), Internal layer tracing and age-depth-accumulation relationships for the northern Greenland ice sheet. J. Geophys. Res-Atmos. Version: 1 106 (D24) 33789-33797, issn: 0747-7309, ids: 522DE, 
• Abdalati, W, W Krabill, E Frederick, S Manizade, C Martin, J Sonntag, R Swift, R Thomas, W Wright and J Yungel (2001), Outlet glacier and margin elevation changes: Near-coastal thinning of the Greenland ice sheet. J. Geophys. Res-Atmos. Version: 1 106 (D24) 33729-33741, issn: 0148-0227, ids: 522DE, 
• Thomas, RH, W Abdalati, TL Akins, BM Csatho, EB Frederick, SP Gogineni, WB Krabill, SS Manizade and EJ Rignot (2000), Substantial thinning of a major east Greenland outlet glacier. Geophys. Res. Lett. Version: 1 27 (9) 1291-1294, issn: 0094-8276, ids: 309BX, 
• Krabill, W, W Abdalati, E Frederick, S Manizade, C Martin, J Sonntag, R Swift, R Thomas, W Wright and J Yungel (2000), Greenland ice sheet: High-elevation balance and peripheral thinning. Science Version: 1 289 (5478) 428-430, issn: 0036-8075, ids: 336ME, 
• Abdalati, W and WB Krabill (1999), Calculation of ice velocities in the Jakobshavn Isbrae area using airborne laser altimetry. Remote Sens. Environ. Version: 1 67 (2) 194-204, issn: 0034-4257, ids: 160XB, 
• Steffen, K, W Abdalati and I Sherjal (1999), Faceted crystal formation in the northeast Greenland low-accumulation region. J. Glaciol. Version: 1 45(149) 63-68, issn: 0022-1430, ids: 193LX
• Abdalati, W and K Steffen (1998), Accumulation and hoar effects on microwave emission in the Greenland ice-sheet dry-snow zones. J. Glaciol. Version: 1 44 (148) 523-531, issn: 0022-1430, ids: 170JW
• Abdalati, W and K Steffen (1997), The apparent effects of the Mt Pinatubo eruption on the Greenland ice sheet melt extent. Geophys. Res. Lett.Version: 1 24 (14) 1795-1797, issn: 0094-8276, ids: XL837, 
• Abdalati, W and K Steffen (1997), Snowmelt on the Greenland ice sheet as derived from passive microwave satellite data. J. Clim. Version: 1 10 (2) 165-175, issn: 0894-8755, ids: WJ835, 
• ABDALATI, W and K STEFFEN (1995), PASSIVE MICROWAVE-DERIVED SNOW MELT REGIONS ON THE GREENLAND ICE-SHEET. Geophys. Res. Lett. Version: 1 22 (7) 787-790, issn: 0094-8276, ids: QR153, 
• ABDALATI, W, K STEFFEN, C OTTO and KC JEZEK (1995), COMPARISON OF BRIGHTNESS TEMPERATURES FROM SSMI INSTRUMENTS ON THE DMSP F8 AND F11 SATELLITES FOR ANTARCTICA AND THE GREENLAND ICE-SHEET. Int. J. Remote Sens. Version: 1 16 (7) 1223-1229, issn: 0143-1161, ids: RG051
• STEFFEN, K, W ABDALATI and J STROEVE (1993), CLIMATE SENSITIVITY STUDIES OF THE GREENLAND ICE-SHEET USING SATELLITE AVHRR, SMMR, SSM/I AND IN-SITU DATA. Meteorol. Atmos. Phys. Version: 1 51 (4-Mar) 239-258, issn: 0177-7971, ids: LM300, 

Updated February 2024