Cooperative Institute for Research in Environmental Sciences

Konrad Steffen

Konrad Steffen

Research Interests

My general interest is the study of processes related to climate and cryosphere interaction in polar and alpine regions based on in-situ and satellite measurements, and using climate system modeling to study their sensitivity. In particular I study and evaluate sea level changes and sensitivity studies of large ice sheets using in situ and modeling results. Most of this research is supported by the NASA/NSF initiative called PARCA: Program in Regional Arctic Climate Assessment.

Current Research

A 2012 update on the Greenland Climate Network and Swiss Camp Climatology (with current and former graduate students Daniel McGrath, William Colgan, Thomas Phillips, and Nicolas Bayou)

The Greenland Climate Network (GC-Net) was established in spring 1990 with the intention to monitor climatological and glaciological parameters at various locations on the Greenland Ice Sheet over several decades to study the climate variability. The first automatic weather station was installed at the Swiss Camp on the western slope of the Greenland Ice Sheet in spring 1990, followed by four automatic weather stations in 1995, four in 1996, five in 1997, four in 1999, one in 2002 and 2003, and the latest one at the European/U.S. deep-icecore site in northwestern Greenland in 2006. The long-term objectives for the Greenland weather station network are to measure daily, annual, and interannual variability in accumulation rate, surface climatology, and surface-energy balance at selected locations on the ice sheet, and to measure near-surface snow density at the GC-Net locations for the assessment of snow densification, accumulation, and metamorphosis.

GC-Net data requests from the beginning of 2009 to the present came from 184 individual users for surface process studies, model validation, and satellite intercomparison. The web interface allows us to capture the email and affiliation of all GC-Net users, including a short description of their use of the Greenland Climate data. Data requests are processed on a UNIX 4-processor workstation and datasets are transferred on a FTP site for direct downloading.

The mean annual air temperature at Swiss Camp is -12.3°C (1991-2009), with the coldest monthly temperature in February (-32°C) and the warmest monthly temperature in July (+1.8ºC). Summer mean monthly temperatures above freezing occurred in 1995 and from 1997 to the present. The mean annual temperature has increased by 4.0°C (about 2°C/decade) using a linear regression model as shown in Figure 1. The temperature minimum in 1992 was the result of the aerosol loading caused by the Mt. Pinatubo eruption. The linear regressing model at 95-percent confidence shows that the Pinatubo cooling and the subsequent warming from the mid 1990s were outside the 95-percentconfidence level. The warming that occurred since 2000 to present shows approximately the same trend as the 19-year time series. The warmest mean annual temperatures were -10.0°C and -10.3°C in 2009 and 2006, respectively.

Radiation has been monitored continuously at Swiss Camp since 1993. The largest monthly mean net radiation is found in the summer of 2007 (> 60 W/m2), coincident with air temperatures above freezing, indicating a strong albedo-feedback mechanism at the equilibrium line altitude (Figure 2). Most of the annual snow cover melted and the bare ice surface was exposed, reducing the monthly albedo value to 0.4 (Figure 3).

It is worth discussing the three anomalous periods of 1995, 1998, and 2001-2009 (Figure 2). The summer season is characterized by a positive net radiation flux, which is indicative of the length of the melting season. High net radiation values can either be the result of low albedo values (i.e., 2003-2009, Figure 3), reduced cloudiness (increase in insolation), or increase in atmospheric temperatures (increase in long-wave radiation). The mean summer net radiation has been higher during the new millennium (30 W/m2) compared to the previous decade, with the exception of record high values in 1995, as a result of increased atmospheric temperatures leading to increase in surface melt (albedo reduction).


Interannual variability of monthly mean air temperatures (1991-2009) at the Swiss Camp, located at the equilibrium-line altitude on the western slope of the Greenland Ice Sheet.

Interannual variability of monthly net radiation (W/m2) at the Swiss Camp (1993-2009).

Interannual variability of monthly mean albedo at the Swiss Camp (1993-2009).

View Publications

  • Ligtenberg, S. R. M., Nol, B. P. Y., Howat, I. M., Box, J. E., Mosley-Thompson, E., McConnell, J. R., Steffen, K., Harper, J. T., Das, S. B., van den Broeke, M. R., Kuipers Munneke, P. (2015), Elevation change of the Greenland Ice Sheet due to surface mass balance and firn processes, 19602014. Cryosphere Version: 1 9 (6) , issn: 19940424, doi: 10.5194/TC-9-2009-2015
  • Miller, NB, MD Shupe, CJ Cox, VP Walden, DD Turner and K Steffen (2015), Cloud Radiative Forcing at Summit, Greenland. J. Clim. Version: 1 28 (15) 6267-6280, issn: 0894-8755, ids: CO9YM, doi: 10.1175/JCLI-D-15-0076.1
  • Steffen, Konrad, Meier, Ueli, Kchli, Christian, Manser, Rolf (2015), Forschung zur richtigen Zeit, umsetzungsorientiert und politisch eingebettet. Swiss J. For. Version: 1 166 (6) , issn: 00367818, doi: 10.3188/SZF.2015.0348
  • Beckerman, Andrew P., Cappelen, John, Hanna, Edward, Malmros, Jeppe K., McConnell, Joseph R., Mernild, Sebastian H., Sigl, Michael, Steffen, Konrad, Yde, Jacob C. (2015), Greenland precipitation trends in a long-term instrumental climate context (1890-2012): evaluation of coastal and ice core records: PRECIPITATION IN GREENLAND. Int. J. Climatol. Version: 1, issn: 10970088, doi: 10.1002/JOC.3986
  • Mernild, Sebastian H., Holland, David M., Holland, Denise, Rosing-Asvid, Aqqalu, Yde, Jacob C., Liston, Glen E., Steffen, Konrad (2015), Freshwater Flux and Spatiotemporal Simulated Runoff Variability into Ilulissat Icefjord, West Greenland, Linked to Salinity and Temperature Observations near Tidewater Glacier Margins Obtained Using Instrumented Ringed Seals. J. Phys. Oceanogr. Version: 1 45 (5) , issn: 00223670, doi: 10.1175/JPO-D-14-0217.1
  • Steen-Larsen, HC, V Masson-Delmotte, M Hirabayashi, R Winkler, K Satow, F Prie, N Bayou, E Brun, KM Cuffey, D Dahl-Jensen, M Dumont, M Guillevic, S Kipfstuhl, A Landais, T Popp, C Risi, K Steffen, B Stenni and AE Sveinbjornsdottir (2014), What controls the isotopic composition of Greenland surface snow?. Clim. Past. Version: 1 10 (1) 377-392, issn: 1814-9324, ids: AE2XV, doi: 10.5194/cp-10-377-2014
  • McGrath, D; Steffen, K; Holland, PR; Scambos, T; Rajaram, H; Abdalati, W; Rignot, E (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, doi: 10.1002/2013JF002935
  • Cox, CJ, VP Walden, GP Compo, PM Rowe, MD Shupe and K Steffen (2014), Downwelling longwave flux over Summit, Greenland, 2010-2012: Analysis of surface-based observations and evaluation of ERA-Interim using wavelets. J. Geophys. Res.-Atmos. Version: 1 119 (21) 12317-12337, issn: 2169-897X, ids: AU6EQ, doi: 10.1002/2014JD021975
  • McGrath, D, W Colgan, N Bayou, A Muto and K Steffen (2013), Recent warming at Summit, Greenland: Global context and implications. Geophys. Res. Lett. Version: 1 40 (10) 2091-2096, issn: 0094-8276, ids: 277SS, doi: 10.1002/grl.50456
  • Bennartz, R, MD Shupe, DD Turner, VP Walden, K Steffen, CJ Cox, MS Kulie, NB Miller and C Pettersen (2013), July 2012 Greenland melt extent enhanced by low-level liquid clouds. Nature Version: 1 496 (7443) 83-86, issn: 0028-0836, ids: 117ZZ, doi: 10.1038/nature12002, PubMed ID: 23552947
  • Petrenko, VV, P Martinerie, P Novelli, DM Etheridge, I Levin, Z Wang, T Blunier, J Chappellaz, J Kaiser, P Lang, LP Steele, S Hammer, J Mak, RL Langenfelds, J Schwander, JP Severinghaus, E Witrant, G Petron, MO Battle, G Forster, WT Sturges, JF Lamarque, K Steffen and JWC White (2013), A 60 yr record of atmospheric carbon monoxide reconstructed from Greenland firn air. Atmos. Chem. Phys. Version: 1 13 (15) 7567-7585, issn: 1680-7316, ids: 200XE, doi: 10.5194/acp-13-7567-2013
  • Phillips, T; Rajaram, H; Colgan, W; Steffen, K; Abdalati, W (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, doi: 10.1002/jgrf.20079
  • Dahl-Jensen, D, MR Albert, A Aldahan, N Azuma, D Balslev-Clausen, M Baumgartner, AM Berggren, M Bigler, T Binder, T Blunier, JC Bourgeois, EJ Brook, SL Buchardt, C Buizert, E Capron, J Chappellaz, J Chung, HB Clausen, I Cvijanovic, SM Davies, P Ditlevsen, O Eicher, H Fischer, DA Fisher, LG Fleet, G Gfeller, V Gkinis, S Gogineni, K Goto-Azuma, A Grinsted, H Gudlaugsdottir, M Guillevic, SB Hansen, M Hansson, M Hirabayashi, S Hong, SD Hur, P Huybrechts, CS Hvidberg, Y Iizuka, T Jenk, SJ Johnsen, TR Jones, J Jouzel, NB Karlsson, K Kawamura, K Keegan, E Kettner, S Kipfstuhl, HA Kjaer, M Koutnik, T Kuramoto, P Kohler, T Laepple, A Landais, PL Langen, LB Larsen, D Leuenberger, M Leuenberger, C Leuschen, J Li, V Lipenkov, P Martinerie, OJ Maselli, V Masson-Delmotte, JR McConnell, H Miller, O Mini, A Miyamoto, M Montagnat-Rentier, R Mulvaney, R Muscheler, AJ Orsi, J Paden, C Panton, F Pattyn, JR Petit, K Pol, T Popp, G Possnert, F Prie, M Prokopiou, A Quiquet, SO Rasmussen, D Raynaud, J Ren, C Reutenauer, C Ritz, T Rockmann, JL Rosen, M Rubino, O Rybak, D Samyn, CJ Sapart, A Schilt, AMZ Schmidt, J Schwander, S Schupbach, I Seierstad, JP Severinghaus, S Sheldon, SB Simonsen, J Sjolte, AM Solgaard, T Sowers, P Sperlich, HC Steen-Larsen, K Steffen, JP Steffensen, D Steinhage, TF Stocker, C Stowasser, AS Sturevik, WT Sturges, A Sveinbjornsdottir, A Svensson, JL Tison, J Uetake, P Vallelonga, RSW van de Wal, G van der Wel, BH Vaughn, B Vinther, E Waddington, A Wegner, I Weikusat, JWC White, F Wilhelms, M Winstrup, E Witrant, EW Wolff, C Xiao and J Zheng (2013), Eemian interglacial reconstructed from a Greenland folded ice core. Nature Version: 1 493 (7433) 489-494, issn: 0028-0836, ids: 075GF, doi: 10.1038/nature11789
  • Hanna, E, JM Jones, J Cappelen, SH Mernild, L Wood, K Steffen and P Huybrechts (2013), The influence of North Atlantic atmospheric and oceanic forcing effects on 1900-2010 Greenland summer climate and ice melt/runoff. Int. J. Climatol. Version: 1 33 (4) 862-880, issn: 0899-8418, ids: 104EE, doi: 10.1002/joc.3475
  • Colgan, W; Rajaram, H; Anderson, RS; Steffen, K; Zwally, HJ; Phillips, T; Abdalati, W (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, doi: 10.3189/2012JoG11J081
  • McGrath, D; Steffen, K; Rajaram, H; Scambos, T; Abdalati, W; Rignot, E (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, doi: 10.1029/2012GL052413
  • Tedesco, M; Luthje, M; Steffen, K; Steiner, N; Fettweis, X; Willis, I; Bayou, N; Banwell, A (2012), Measurement and modeling of ablation of the bottom of supraglacial lakes in western Greenland. Geophys. Res. Lett. Version: 1 39 , Art. No. L02502, issn: 0094-8276, ids: 880GO, doi: 10.1029/2011GL049882
  • Liang, YL; Colgan, W; Lv, Q; Steffen, K; Abdalati, W; Stroeve, J; Gallaher, D; Bayou, N (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, doi: 10.1016/j.rse.2012.03.020
  • Box, JE, X Fettweis, JC Stroeve, M Tedesco, DK Hall and K Steffen (2012), Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers. Cryosphere Version: 1 6 (4) 821-839, issn: 1994-0416, ids: 998NJ, doi: 10.5194/tc-6-821-2012
  • McGrath, D, K Steffen, T Scambos, H Rajaram, G Casassa and JLR Lagos (2012), Basal crevasses and associated surface crevassing on the Larsen C ice shelf, Antarctica, and their role in ice-shelf instability. Ann. Glaciol. Version: 1 53 (60) 10-18, issn: 0260-3055, ids: 095BU, doi: 10.3189/2012AoG60A005
  • Hanna, E, P Huybrechts, J Cappelen, K Steffen, RC Bales, E Burgess, JR McConnell, JP Steffensen, M Van den Broeke, L Wake, G Bigg, M Griffiths and D Savas (2011), Greenland Ice Sheet surface mass balance 1870 to 2010 based on Twentieth Century Reanalysis, and links with global climate forcing. J. Geophys. Res.-Atmos. Version: 1 116 , Art. No. D24121, issn: 2169-897X, ids: 871OH, doi: 10.1029/2011JD016387
  • Phillips, T; Leyk, S; Rajaram, H; Colgan, W; Abdalati, W; McGrath, D; Steffen, K (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, doi: 10.1016/j.rse.2011.04.029
  • Steen-Larsen, HC, V Masson-Delmotte, J Sjolte, SJ Johnsen, BM Vinther, FM Breon, HB Clausen, D Dahl-Jensen, S Falourd, X Fettweis, H Gallee, J Jouzel, M Kageyama, H Lerche, B Minster, G Picard, HJ Punge, C Risi, D Salas, J Schwander, K Steffen, AE Sveinbjornsdottir, A Svensson and J White (2011), Understanding the climatic signal in the water stable isotope records from the NEEM shallow firn/ice cores in northwest Greenland. J. Geophys. Res.-Atmos. Version: 1 116 , Art. No. D06108, issn: 2169-897X, ids: 741LO, doi: 10.1029/2010JD014311
  • Colgan, W; Rajaram, H; Anderson, R; Steffen, K; Phillips, T; Joughin, I; Zwally, HJ; Abdalati, W (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, doi: 10.3189/002214311797409668
  • Fausto, RS, AP Ahlstrom, D Van As and K Steffen (2011), Present-day temperature standard deviation parameterization for Greenland. J. Glaciol. Version: 1 57 (206) 1181-1183, issn: 0022-1430, ids: 864GC
  • Colgan, W; Steffen, K; McLamb, WS; Abdalati, W; Rajaram, H; Motyka, R; Phillips, T; Anderson, R (2011), An increase in crevasse extent, West Greenland: Hydrologic implications. Geophys. Res. Lett. Version: 1 38 , Art. No. L18502, issn: 0094-8276, ids: 823PQ, doi: 10.1029/2011GL048491
  • Muto, A, TA Scambos, K Steffen, AG Slater and GD Clow (2011), Recent surface temperature trends in the interior of East Antarctica from borehole firn temperature measurements and geophysical inverse methods. Geophys. Res. Lett. Version: 1 38 , Art. No. L15502, issn: 0094-8276, ids: 807PF, doi: 10.1029/2011GL048086
  • McGrath, D, W Colgan, K Steffen, P Lauffenburger and J Balog (2011), Assessing the summer water budget of a moulin basin in the Sermeq Avannarleq ablation region, Greenland ice sheet. J. Glaciol. Version: 1 57 (205) 954-964, issn: 0022-1430, ids: 836NP
  • Mernild, SH, IM Howat, Y Ahn, GE Liston, K Steffen, BH Jakobsen, B Hasholt, B Fog and D van As (2010), Freshwater flux to Sermilik Fjord, SE Greenland. Cryosphere Version: 1 4 (4) 453-465, issn: 1994-0416, ids: 698FK, doi: 10.5194/tc-4-453-2010
  • Mernild, SH, GE Liston, K Steffen and P Chylek (2010), Meltwater flux and runoff modeling in the ablation area of Jakobshavn Isbrae, West Greenland. J. Glaciol. Version: 1 56 (195) 20-32, issn: 0022-1430, ids: 642YK
  • Phillips, T, H Rajaram and K Steffen (2010), Cryo-hydrologic warming: A potential mechanism for rapid thermal response of ice sheets. Geophys. Res. Lett. Version: 1 37 , Art. No. L20503, issn: 0094-8276, ids: 704YK, doi: 10.1029/2010GL044397
  • Mernild, SH, GE Liston, K Steffen, M van den Broeke and B Hasholt (2010), Runoff and mass-balance simulations from the Greenland Ice Sheet at Kangerlussuaq (Sondre Stromfjord) in a 30-year perspective, 1979-2008. Cryosphere Version: 1 4 (2) 231-242, issn: 1994-0416, ids: 618XR, doi: 10.5194/tc-4-231-2010
  • Ettema, J, MR van den Broeke, E van Meijgaard, WJ van de Berg, JE Box and K Steffen (2010), Climate of the Greenland ice sheet using a high-resolution climate model - Part 1: Evaluation. Cryosphere Version: 1 4 (4) 511-527, issn: 1994-0416, ids: 698FK, doi: 10.5194/tc-4-511-2010
  • McGrath, D, K Steffen, I Overeem, SH Mernild, B Hasholt and M van den Broeke (2010), Sediment plumes as a proxy for local ice-sheet runoff in Kangerlussuaq Fjord, West Greenland. J. Glaciol. Version: 1 56 (199) 813-821, issn: 0022-1430, ids: 709AL, doi: 10.3189/002214310794457227
  • Fausto, RS, AP Ahlstrom, D van As, SJ Johnsen, PL Langen and K Steffen (2009), Improving surface boundary conditions with focus on coupling snow densification and meltwater retention in large-scale ice-sheet models of Greenland. J. Glaciol. Version: 1 55 (193) 869-878, issn: 0022-1430, ids: 544RH
  • Munneke, PK, MR van den Broeke, CH Reijmer, MM Helsen, W Boot, M Schneebeli and K Steffen (2009), The role of radiation penetration in the energy budget of the snowpack at Summit, Greenland. Cryosphere Version: 1 3 (2) 155-165, issn: 1994-0416, ids: 576QS
  • Mernild, SH, GE Liston, CA Hiemstra, K Steffen, E Hanna and JH Christensen (2009), Greenland Ice Sheet surface mass-balance modelling and freshwater flux for 2007, and in a 1995-2007 perspective. Hydrol. Process. Version: 1 23 (17) 2470-2484, issn: 0885-6087, ids: 485EG, doi: 10.1002/hyp.7354
  • Rial, JA, C Tang and K Steffen (2009), Glacial rumblings from Jakobshavn ice stream, Greenland. J. Glaciol. Version: 1 55 (191) 389-399, issn: 0022-1430, ids: 483CP
  • Doherty, SJ, S Bojinski, A Henderson-Sellers, K Noone, D Goodrich, NL Bindoff, JA Church, KA Hibbard, TR Karl, L Kajefez-Bogataj, AH Lynch, DE Parker, IC Prentice, V Ramaswamy, RW Saunders, MS Smith, K Steffen, TF Stocker, PW Thorne, KE Trenberth, MM Verstraete and FW Zwiers (2009), LESSONS LEARNED FROM IPCC AR4 Scientific Developments Needed To Understand, Predict, And Respond To Climate Change. Bull. Amer. Meteorol. Soc. Version: 1 90 (4) 497-513, issn: 0003-0007, ids: 445FI, doi: 10.1175/2008BAMS2643.1
  • Mernild, SH, GE Liston, CA Hiemstra and K Steffen (2008), Surface Melt Area and Water Balance Modeling on the Greenland Ice Sheet 1995-2005. J. Hydrometeorol. Version: 1 9 (6) 1191-1211, issn: 1525-755X, ids: 386DD, doi: 10.1175/2008JHM957.1
  • Hall, DK, JE Box, KA Casey, SJ Hook, CA Shuman and K Steffen (2008), Comparison of satellite-derived and in-situ observations of ice and snow surface temperatures over Greenland. Remote Sens. Environ. Version: 1 112 (10) 3739-3749, issn: 0034-4257, ids: 356SO, doi: 10.1016/j.rse.2008.05.007
  • Rignot, E and K Steffen (2008), Channelized bottom melting and stability of floating ice shelves. Geophys. Res. Lett. Version: 1 35 (2) , Art. No. L02503, issn: 0094-8276, ids: 254DR, doi: 10.1029/2007GL031765
  • Hanna, E, P Huybrechts, K Steffen, J Cappelen, R Huff, C Shuman, T Irvine-Fynn, S Wise and M Griffiths (2008), Increased runoff from melt from the Greenland Ice Sheet: A response to global warming. J. Clim. Version: 1 21 (2) 331-341, issn: 0894-8755, ids: 256CF, doi: 10.1175/2007JCLI1964.1
  • Wang, L, M Sharp, B Rivard and K Steffen (2007), Melt season duration and ice layer formation on the Greenland ice sheet, 2000-2004. J. Geophys. Res.-Earth Surf. Version: 1 112 (F4) , Art. No. F04013, issn: 2169-9003, ids: 244QE, doi: 10.1029/2007JF000760
  • Cullen, NJ, K Steffen and PD Blanken (2007), Nonstationarity of turbulent heat fluxes at Summit, Greenland. Bound.-Layer Meteorol. Version: 1 122 (2) 439-455, issn: Jun-14, ids: 131WX, doi: 10.1007/s10546-006-9112-2
  • Painter, TH, NP Molotch, M Cassidy, M Flanner and K Steffen (2007), Instruments and methods - Contact spectroscopy for determination of stratigraphy of snow optical grain size. J. Glaciol. Version: 1 53 (180) 121-127, issn: 0022-1430, ids: 161IK, doi: 10.3189/172756507781833947
  • Nghiem, S. V., K. Steffen, G. Neumann and R. Huff (2007), Snow accumulation and snowmelt monitoring in Greenland and Antarctica. Version: 1 DYNAMIC PLANET: MONITORING AND UNDERSTANDING A DYNAMIC PLANET WITH GEODETIC AND OCEANOGRAPHIC TOOLS IAG Symposium on Dynamic PlanetIAG Symposium on Dynamic Planet 130 31-+, Cairns, AUSTRALIACairns, AUSTRALIA, AUG 22-26, 2005AUG 22-26, 2005, Ed. Tregoning, P; Rizos, C, issn: 0939-9585, isbn: 978-3-540-49349-5
  • Alfieri, JG, PD Blanken, DN Yates and K Steffen (2007), Variability in the environmental factors driving evapotranspiration from a grazed rangeland during severe drought conditions. J. Hydrometeorol. Version: 1 8 (2) 207-220, issn: 1525-755X, ids: 162BK, doi: 10.1175/JHM569.1
  • Cullen, NJ, T Molg, G Kaser, K Hussein, K Steffen and DR Hardy (2006), Kilimanjaro Glaciers: Recent areal extent from satellite data and new interpretation of observed 20th century retreat rates. Geophys. Res. Lett. Version: 1 33 (16) , Art. No. L16502, issn: 0094-8276, ids: 081QD, doi: 10.1029/2006GL027084
  • Box, JE, DH Bromwich, BA Veenhuis, LS Bai, JC Stroeve, JC Rogers, K Steffen, T Haran and SH Wang (2006), Greenland ice sheet surface mass balance variability (1988-2004) from calibrated polar MM5 output. J. Clim. Version: 1 19 (12) 2783-2800, issn: 0894-8755, ids: 057ZT, doi: 10.1175/JCLI3738.1
  • Nghiem, SV, K Steffen, G Neumann and R Huff (2005), Mapping of ice layer extent and snow accumulation in the percolation zone of the Greenland ice sheet. J. Geophys. Res.-Earth Surf. Version: 1 110 (F2) , Art. No. F02017, issn: 0148-0227, ids: 940UH, doi: 10.1029/2004JF000234
  • Orr, A, E Hanna, JCR Hunt, J Cappelen, K Steffen and AG Stephens (2005), Characteristics of stable flows over Southern Greenland. Pure Appl. Geophys. Version: 1 162 (10) 1747-1778, issn: 0033-4553, ids: 948LW, doi: 10.1007/s00024-005-2691-x
  • Hanna, E, P Huybrechts, I Janssens, J Cappelen, K Steffen and A Stephens (2005), Runoff and mass balance of the Greenland ice sheet: 1958-2003. J. Geophys. Res.-Atmos. Version: 1 110 (D13) , Art. No. D13108, issn: 2169-897X, ids: 950CQ, doi: 10.1029/2004JD005641
  • Steffen, K, SV Nghiem, R Huff and G Neumann (2004), The melt anomaly of 2002 on the Greenland Ice Sheet from active and passive microwave satellite observations. Geophys. Res. Lett. Version: 1 31 (20) , Art. No. L20402, issn: 0094-8276, ids: 867XJ, doi: 10.1029/2004GL020444
  • Smith, LC, YW Sheng, RR Forster, K Steffen, KE Frey and DE Alsdorf (2003), Melting of small Arctic ice caps observed from ERS scatterometer time series. Geophys. Res. Lett. Version: 1 30 (20) , Art. No. 2034, issn: 0094-8276, ids: 736XE, doi: 10.1029/2003GL017641
  • Thomas, RH; Abdalati, W; Frederick, E; Krabill, WB; Manizade, S; Steffen, K (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, doi: 10.3189/172756503781830764
  • Zwally, HJ; Abdalati, W; Herring, T; Larson, K; Saba, J; Steffen, K (2002), Surface melt-induced acceleration of Greenland ice-sheet flow. Science Version: 1 297 (5579) 218-222, issn: 0036-8075, ids: 571UT, doi: 10.1126/science.1072708, PubMed ID: 12052902
  • Dassau, TM, AL Sumner, SL Koeniger, PB Shepson, J Yang, RE Honrath, NJ Cullen, K Steffen, HW Jacobi, M Frey and RC Bales (2002), Investigation of the role of the snowpack on atmospheric formaldehyde chemistry at Summit, Greenland. J. Geophys. Res.-Atmos. Version: 1 107 (D19) , Art. No. 4394, issn: 0148-0227, ids: 635YT, doi: 10.1029/2002JD002182
  • Honrath, RE, Y Lu, MC Peterson, JE Dibb, MA Arsenault, NJ Cullen and K Steffen (2002), Vertical fluxes of NOx, HONO, and HNO3 above the snowpack at Summit, Greenland. Atmos. Environ. Version: 1 36 (15-16) 2629-2640, Art. No. PII S1352-2310(02)00132-2, issn: 1352-2310, ids: 569QU, doi: 10.1016/S1352-2310(02)00132-2
  • Jacobi, HW, MM Frey, MA Hutterli, RC Bales, O Schrems, NJ Cullen, K Steffen and C Koehler (2002), Measurements of hydrogen peroxide and formaldehyde exchange between the atmosphere and surface snow at Summit, Greenland. Atmos. Environ. Version: 1 36 (15-16) 2619-2628, Art. No. PII S1352-2310(02)00106-1, issn: 1352-2310, ids: 569QU, doi: 10.1016/S1352-2310(02)00106-1
  • Helmig, D, J Boulter, D David, JW Birks, NJ Cullen, K Steffen, BJ Johnson and SJ Oltmans (2002), Ozone and meteorological Summit, Greenland, boundary-layer conditions at during 3-21 June 2000. Atmos. Environ. Version: 1 36 (15-16) 2595-2608, Art. No. PII S1352-2310(02)00129-2, issn: 1352-2310, ids: 569QU, doi: 10.1016/S1352-2310(02)00129-2
  • Bromwich, DH; Cassano, JJ; Klein, T; Heinemann, G; Hines, KM; Steffen, K; Box, JE (2001), Mesoscale modeling of katabatic winds over Greenland with the Polar MM5. Mon. Weather Rev. Version: 1 129 (9) 2290-2309, issn: 0027-0644, ids: 465XN, doi: 10.1175/1520-0493(2001)129<2290:MMOKWO>2.0.CO;2
  • Nghiem, SV, K Steffen, R Kwok and WY Tsai (2001), Detection of snowmelt regions on the Greenland ice sheet using diurnal backscatter change. J. Glaciol. Version: 1 47 (159) 539-547, issn: 0022-1430, ids: 546BT, doi: 10.3189/172756501781831738
  • Cassano, JJ; Box, JE; Bromwich, DH; Li, L; Steffen, K (2001), Evaluation of polar MM5 simulations of Greenlands atmospheric circulation. J. Geophys. Res.-Atmos. Version: 1 106 (D24) 33867-33889, issn: 2169-897X, ids: 522DE, doi: 10.1029/2001JD900044
  • Mosley-Thompson, E, JR McConnell, RC Bales, PN Lin, K Steffen, LG Thompson, R Edwards and D Bathke (2001), Local to regional-scale variability of annual net accumulation on the Greenland ice sheet from PARCA cores. J. Geophys. Res.-Atmos. Version: 1 106 (D24) 33839-33851, issn: 2169-897X, ids: 522DE, doi: 10.1029/2001JD900067
  • Steffen, K and J Heinrichs (2001), C-band SAR backscatter characteristics of Arctic Sea and land ice during winter. Atmos.-Ocean Version: 1 39 (3) 289-299, issn: 0705-5900, ids: 487VE
  • Thomas, RH and PARCA Investigators (2001), Program for arctic regional climate assessment (PARCA): Goals, key findings, and future directions. J. Geophys. Res.-Atmos. Version: 1 106 (D24) 33691-33705
  • Steffen, K and J Box (2001), Surface climatology of the Greenland ice sheet: Greenland climate network 1995-1999. J. Geophys. Res.-Atmos. Version: 1 106 (D24) 33951-33964, issn: 2169-897X, ids: 522DE, doi: 10.1029/2001JD900161
  • Cullen, NJ and K Steffen (2001), Unstable near-surface boundary conditions in summer on top of the Greenland ice sheet. Geophys. Res. Lett. Version: 1 28 (23) 4491-4493, issn: 0094-8276, ids: 496YJ, doi: 10.1029/2001GL013417
  • Comiso, JC and K Steffen (2001), Studies of Antarctic sea ice concentrations from satellite data and their applications. J. Geophys. Res.-Oceans Version: 1 106 (C12) 31361-31385, issn: 0148-0227, ids: 513WB, doi: 10.1029/2001JC000823
  • Box, JE and K Steffen (2001), Sublimation on the Greenland ice sheet from automated weather station observations. J. Geophys. Res.-Atmos. Version: 1 106 (D24) 33965-33981, issn: 2169-897X, ids: 522DE, doi: 10.1029/2001JD900219
  • Abdalati, W; Steffen, K (2001), Greenland ice sheet melt extent: 1979-1999. J. Geophys. Res.-Atmos. Version: 1 106 (D24) 33983-33988, issn: 2169-897X, ids: 522DE, doi: 10.1029/2001JD900181
  • Shuman, CA, K Steffen, JE Box and CR Stearns (2001), A dozen years of temperature observations at the summit: central Greenland automatic weather stations 1987-99. J. Appl. Meteorol. Version: 1 40 (4) 741-752, issn: 0894-8763, ids: 420TV, doi: 10.1175/1520-0450(2001)040<0741:ADYOTO>2.0.CO;2
  • Weaver, RLS, K Steffen, J Heinrichs, JA Maslanik and GM Flato (2000), Data assimilation in sea-ice monitoring. Version: 1 ANNALS OF GLACIOLOGY, VOL 31, 2000 International Symposium on the Verification of Cryospheric Models 31 327-332, SWISS FED INST TECHNOL, ZURICH, SWITZERLAND, AUG 16-20, 1999, Ed. Steffen, K, issn: 0260-3055, ids: BR60H, isbn: 0-946417-26-1, doi: 10.3189/172756400781820039
  • Steffen, K; Abdalati, W; Sherjal, I (1999), Faceted crystal formation in the northeast Greenland low-accumulation region. J. Glaciol. Version: 1 45 (149) 63-68, issn: 0022-1430, ids: 193LX, doi: 10.3189/S002214300000304X
  • Anklin, M, RC Bales, E Mosley-Thompson and K Steffen (1998), Annual accumulation at two sites in northwest Greenland during recent centuries. J. Geophys. Res.-Atmos. Version: 1 103 (D22) 28775-28783, issn: 2169-897X, ids: 142JB, doi: 10.1029/98JD02718
  • Abdalati, W; Steffen, K (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
  • Serreze, MC; Key, JR; Box, JE; Maslanik, JA; Steffen, K (1998), A new monthly climatology of global radiation for the Arctic and comparisons with NCEP-NCAR reanalysis and ISCCP-C2 fields. J. Clim. Version: 1 11 (2) 121-136, issn: 0894-8755, ids: YY523, doi: 10.1175/1520-0442(1998)011<0121:ANMCOG>2.0.CO;2
  • Stroeve, J and K Steffen (1998), Variability of AVHRR-derived clear-sky surface temperature over the Greenland ice sheet. J. Appl. Meteorol. Version: 1 37 (1) 23-31, issn: 0894-8763, ids: YQ932, doi: 10.1175/1520-0450(1998)037<0023:VOADCS>2.0.CO;2
  • Abdalati, W; Steffen, K (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, doi: 10.1029/97GL01706
  • Abdalati, W; Steffen, K (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, doi: 10.1175/1520-0442(1997)010<0165:SOTGIS>2.0.CO;2
  • Stroeve, J, A Nolin and K Steffen (1997), Comparison of AVHRR-derived and in situ surface albedo over the Greenland ice sheet. Remote Sens. Environ. Version: 1 62 (3) 262-276, issn: 0034-4257, ids: YD929, doi: 10.1016/S0034-4257(97)00107-7
  • Steffen, K and T DeMaria (1996), Surface energy fluxes of arctic winter sea ice in Barrow strait. J. Appl. Meteorol. Version: 1 35 (11) 2067-2079, issn: 0894-8763, ids: VV053, doi: 10.1175/1520-0450(1996)035<2067:SEFOAW>2.0.CO;2
  • Stroeve, J, M Haefliger and K Steffen (1996), Surface temperature from ERS-1 ATSR infrared thermal satellite data in polar regions. J. Appl. Meteorol. Version: 1 35 (8) 1231-1239, issn: 0894-8763, ids: VE128, doi: 10.1175/1520-0450(1996)035<1231:STFAIT>2.0.CO;2
  • ABDALATI, W; STEFFEN, K (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, doi: 10.1029/95GL00433
  • ABDALATI, W; STEFFEN, K; OTTO, C; JEZEK, KC (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, doi: 10.1080/01431169508954473
  • STEFFEN, K and J HEINRICHS (1994), FEASIBILITY OF SEA-ICE TYPING WITH SYNTHETIC-APERTURE-RADAR (SAR) - MERGING OF LANDSAT THEMATIC MAPPER AND ERS-1 SAR SATELLITE IMAGERY. J. Geophys. Res.-Oceans Version: 1 99 (C11) 22413-22424, issn: 0148-0227, ids: PR668, doi: 10.1029/94JC01398
  • STEFFEN, K; ABDALATI, W; STROEVE, J (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, doi: 10.1007/BF01030497
  • STEFFEN, K and JE LEWIS (1988), SURFACE TEMPERATURES AND SEA ICE TYPING FOR NORTHERN BAFFIN-BAY. Int. J. Remote Sens. Version: 1 9 (3) 409-422, issn: 0143-1161, ids: N4477
  • STEFFEN, K (1986), ICE CONDITIONS OF AN ARCTIC POLYNYA - NORTH WATER IN WINTER. J. Glaciol. Version: 1 32 (112) 383-390, issn: 0022-1430, ids: F8398
  • STEFFEN, K and A OHMURA (1985), HEAT-EXCHANGE AND SURFACE CONDITIONS IN NORTH WATER, NORTHERN BAFFIN-BAY. Ann. Glaciol. Version: 1 6 178-181, issn: 0260-3055, ids: AUT51
  • STEFFEN, K (1985), WARM WATER CELLS IN THE NORTH WATER, NORTHERN BAFFIN-BAY DURING WINTER. J. Geophys. Res. Oceans Version: 1 90 (NC5) 9129-9136, ids: AQS38, doi: 10.1029/JC090iC05p09129