Spatio-temporal variability of snowmelt across Svalbard during the period 2000–08 derived from QuikSCAT/SeaWinds scatterometry

Figures & data

Fig. 1.  Area of investigation: the archipelago of Svalbard between 74° and 81°N and 10° and 35°E, for the purpose of this study subdivided into regions R1–R7. About 60% (3.6×10⁴ km²) of the total land surface is glaciated with most continuous ice coverage to be found in north-eastern regions (R6 and R7). The location of automatic weather stations (AWS) on Nordaustlandet is shown.

Table 1. Meteorological data available for calibrating and validating the melt analysis of this study.

Site	Coordinates	Altitude	Region	In operation from	Source
Automatic weather station 1	22.42, 79.73	368	7 (Austfonna)	Apr 2004	Schuler et al. 2007
Automatic weather station 2	22.83, 79.77	536	7 (Austfonna)	Apr 2004
Miniature temperature-logger	24.24, 79.94	810	7 (Austfonna summit)	Apr 2004	Schuler unpubl. data
Ny-Ålesund	11.93, 78.92	8	2 (western Spitsbergen)	Aug 1974	www.eklima.met.no
Svalbard Airport	15.47, 78.25	28	1 (eastern Spitsbergen)	Aug 1975
Sveagruva	16.72, 77.88	9	1 (eastern Spitsbergen)	May 1978
Hornsund	15.50, 77.00	10	1 (eastern Spitsbergen)	Jun 1985

Fig. 2.  Nine-year time series (2000–08) of the average backscattering (σ^o_mean) for all ice-covered areas within Region 1 and Region 2 (for boundaries see Fig. 1) compared to corresponding temperature records from local weather stations.

Fig. 4.  Mean and standard-deviation patterns of (a) annual total number of melt days (ATMD) and (b) summer melt onset (SMO) with respect to the 2000–08 period of observation.

Fig. 5.  Svalbard annual total number of melt days (ATMD) and summer melt onset (SMO) anomalies relative to the 2000–08 average.

Fig. 6.  Regional averages of (a) annual total number of melt days (ATMD) and (b) summer melt onset (SMO) from 2000 to 2008.

Table 2. Regional annual total number of melt days and summer melt onset from 2000 to 2008.

	Annual total number of melt days (ATMD)												Summer melt onset (SMO)
	2000	2001	2002	2003	2004	2005	2006	2007	2008	Mean		2000	2001	2002	2003	2004	2005	2006	2007	2008	Mean
R1	89	88	99	88	99	82	121	101	108	97		162	159	145	151	144	155	118	151	148	148
R2	75	84	92	79	83	72	93	72	86	82		170	161	146	160	158	154	136	154	158	155
R3	66	95	88	63	71	80	91	80	87	80		171	161	146	169	166	157	152	159	166	161
R4	65	75	74	58	82	84	109	86	92	81		173	162	147	171	166	155	115	154	163	156
R5	79	64	81	71	74	82	119	99	106	86		166	161	146	168	166	154	114	154	152	153
R6	57	98	95	73	81	86	88	73	78	81		174	162	147	170	168	156	155	164	173	163
R7	65	101	93	73	78	86	92	81	81	83		173	162	147	170	169	158	147	163	174	163
Svalbard mean	71	87	89	72	81	82	102	85	91	84		170	161	146	166	162	156	134	157	162	157

Fig. 7.  Average QuikSCAT backscatter response for Region 1 in (a) 2000 and (b) 2006 compared to air temperature and precipitation data from local weather stations.

Fig. 8.  Synchronous melt onset over all of Svalbard: (a) σ^o_mean-time series for seven Svalbard regions in 2001, and (b) US National Centers for Environmental Prediction and US National Center for Atmospheric Research (NCEP/NCAR) maps of air-temperature fields from 9 to 15 June 2001.

Fig. 9.  Regional σ^o_mean as a function of elevation and time for all regions in (a) 2001, (b) 2006 and (c) from January 2000 to December 2008 in Region 3.

Fig. 10.  SMO as derived from albedo studies (filled dots) presented by Winther et al. (2002), and from QuikSCAT backscatter signature (circles) at Ny-Ålesund.

Fig. 11.  Comparison of daily backscatter and air temperature measurements from 2004–08 at Austfonna summit. Horizontal lines mark σ^o_Tr in each year.

Fig. 12.  Comparison of daily air temperatures and corresponding QuikSCAT-backscatter time series from 2004 to 2007 at the location of automatic weather station 1 (AWS 1) on Etonbreen, Austfonna. Vertical lines mark dates at which winter snow had disappeared and bare ice was exposed at the surface according to local sonic ranger measurements.