Лёд и Снег · 2020 · Т. 60 · № 1

УДК 551.32

doi: 10.31857/S2076673420010021

Изменения высоты поверхности и баланс массы

ледникового купола Академии Наук на Северной Земле

¹Высшая техническая школа инженеров телекоммуникаций Мадридского политехнического университета, Мадрид, Испания;

²Институт географии РАН, Москва, Россия

^*francisco.navarro@upm.es

Surface-elevation changes and mass balance

of the Academy of Sciences Ice Cap, Severnaya Zemlya

F.J. Navarro^1*, P. Sánchez-Gámez¹, A.F. Glazovsky², C. Recio-Blitz¹

¹ETSI de Telecomunicación, Universidad Politécnica de Madrid; ²Institute of Geography, Russian Academy of Sciences, Moscow, Russia

^*francisco.navarro@upm.es

Received November 5, 2019 / Revised November 20, 2019 / Accepted December 13, 2019

Keywords: Arctic, glacier mass balance, ice cap, ice surface-elevation change, Severnaya Zemlya.

Summary

We have determined the surface-elevation change rates of the Academy of Sciences Ice Cap, Severnaya Zemlya,

Russian Arctic, for two different periods: 2004-2016 and 2012/2013-2016. The former was calculated from differ-

encing of ICESat and ArcticDEM digital elevation models, while the latter was obtained by differencing two sets

of ArcticDEM digital elevation models. From these surface-elevation change rates we obtained the geodetic mass

balance, which was nearly identical for both periods, at -1,72±0,67 Gt a^-1, equivalent to -0,31±0,12 m w.e. a^-1

over the whole ice cap area. Using an independent estimate of frontal ablation for 2016-2017 of -1,93±0,12 Gt a^-1

(-0,31±0,12 m w.e. a^-1), we get an estimate of the climatic mass balance not significantly different from zero,

at 0,21±0,68 Gt a^-1 (0,04±0,13 m w.e. a^-1), which agrees with the near-zero average balance at a decadal scale

observed during the last four decades. Making an observationally-based assumption on accumulation rate, we

estimate the current total ablation from the ice cap, and its partitioning between frontal ablation, dominated by

calving (~54%) and climatic mass balance, mostly surface ablation (~46%).

Citation: Navarro F.J., Sánchez-Gámez Р., Glazovsky A.F., Recio-Blitz C. Surface-elevation changes and mass balance of the Academy of Science Ice Cap,

Severnaya Zemlya. Led i Sneg. Ice and Snow. 2020. 60 (1): 29-41. [In Russian]. doi: 10.31857/S2076673420010021.

Поступила 5 ноября 2019 г. / После доработки 20 ноября 2019 г. / Принята к печати 13 декабря 2019 г.

Ключевые слова: Арктика, баланс массы ледника, изменения высоты ледниковой поверхности, ледниковый купол, Северная Земля.

На основе разновременных ЦМР установлены скорости изменения высоты поверхности ледни-

кового купола Академии Наук на Северной Земле за два периода: 2004-2016 и 2012/2013-2016 гг.

и определён геодезический баланс его массы (-1,72±0,67 Гт/год). Сделан расчёт климатиче-

ского баланса массы (0,21±0,68 Гт/год) и полной абляции (-3,18 Гт/год) ледника, где на отёл прихо-

дится ≈54%, а на поверхностную абляцию - ≈46%.

Introduction

the mass losses from the Russian Arctic to the end of

the 21st century have been projected to increase con

The Russian Arctic, which is made up of the ar

siderably [5], with an expected contribution to sea-

chipelagos of Novaya Zemlya, Severnaya Zemlya

level rise varying between 9.5±4.6 and 18.1±5.5 mm

and Franz Josef Land, had a total glacierized area of

in sea-level equivalent over 2010-2100, depending on

51 592 km² in 2000-2010 [1] and an estimated total

the emission scenario [6]. Hence the interest of an ac

ice volume of 16 839±2205 km³ [2]. In spite of cur

curate knowledge of the current mass losses from the

rent regional climate warming [3], the recent ice-mass

Russian Arctic. There are, however, substantial dif

losses from the Russian Arctic have been moderate,

ferences among the various estimates of current mass

at ~11±4 Gt a^-1 over 2003-2009 [4], which is much

losses, not only among those obtained using different

lower than other Arctic regions such as the Canadian

techniques, such as ICESat altimetry versus GRACE

Arctic, the Greenland periphery or Alaska, even when

gravimetry, but also among those obtained using a

specific (per unit area) losses are considered. However,

common technique. For instance, Moholdt et al. [7]

 29 

Ледники и ледниковые покровы

found mass changes of -9.8±1.9 Gt a^-1 using ICESat

briefly outline the main previous studies on regional

data and -7.1±5.5 Gt a^-1 using GRACE data, both

mass balance available in the literature.

for the same period October 2003 - October 2009.

The climate of Severnaya Zemlya can be consid

The spread among the GRACE estimates is also rather

ered as a polar desert with both low temperatures and

large. For instance, mass changes of -4.6±5.4 Gt a^-1

low precipitation [7]. The atmospheric circulation is

have been found for April 2003 - March 2011 [7], of

dominated by high-pressure areas over Siberia and the

-5±3 Gt a^-1 for January 2003 - December 2010 [8],

Arctic Ocean, and low pressure over the Barents and

of -15.4±11.9 Gt a^-1 for February 2004 - Janu

Kara seas [20, 21]. There is a south-north gradient in

ary 2008 [9], and of -6.9±7.4 Gt a^-1 for February

precipitation, with the Kara Sea as a probable moisture

2004 - January 2012 [9]. These differences among

source [21, 22]. This precipitation gradient is demon

the GRACE estimates can be attributed to the non-

strated by the decrease of the ELA in Severnaya Zem

overlapping study periods, to GRACE’s large footprint

lya, as we move from south to north, from ~600 m for

(~250 km), and to uncertainties in the glacier-isostat

the Vavilov Ice Cap, ~400 m for the Academy of Sci

ic adjustment correction, which is known to be poorly

ences Ice Cap and ~200 m for Schmidt Island [16, 23].

constrained in this region [10].

There are two permanent weather stations in the

Since most of the recent ice-mass losses in the Rus

region, Golomyanny and Fedorova (Fig. 1, a of [19]),

sian Arctic have occurred in Novaya Zemlya (~80%),

providing meteorological records from the 1930s to

while only the the remaining ~20% correspond to

the present [20, 24]. The mean annual surface air

Severnaya Zemlya and Franz Josef Land [7], most re

temperatures recorded at these stations are of -14.7

cent studies have focused on Novaya Zemlya. A par

and -15 °C, respectively, with Fedorova register

ticular aim has been to determine the main drivers (cli

ing a mean July temperature of 1.5 °C for the period

mate, glacier dynamics) of the large ice-mass losses

1930-1990 [24]. Mean annual precipitation is also

from Novaya Zemlya [7, 11, 12]. Recent work has re

similar for both weather stations, at ~0.19 m w.e. for

vealed that the retreat rates of the marine-terminating

Golomyanny and ~0.20 m w.e. for Fedorova [20, 24].

outlet glaciers of Novaya Zemlya’s may have slowed

However, Zhao et al. [22] showed that NCEP-NCAR

down [13]. The study of the mass balance of Severna

reanalysis summer temperatures at free air 850 hPa

ya Zemlya glaciers [14-16] or Franz Josef Land [17]

geopotential height over Severnaya Zemlya [25] have

has received comparatively lower attention by the west

weak correlations with the summer mean tempera

ern literature. This motivated our work in a previous

tures measured at Golomyanny Island station. They

paper [18], which had a wider scope, dealing with the

noted that this station is located within the Severna

short-term and long-term variations of ice-surface ve

ya Zemlya archipelago 130 km away from the ice cap

locity, and associated ice discharge variations, the stress

to the southwest into the Kara Sea, at only 7 m a.s.l.,

regime, the surface-elevation changes and their asso

and is strongly influenced by the ocean environ

ciated mass-balance changes. In the present paper, we

ment due to sea-ice melting in summer. Addition

expand the discussion by Sánchez-Gámez et al. [18],

ally, Opel et al. [26] found no correspondence be

focusing on the surface-elevation changes and the geo

tween the number of melt layers in an ice core drilled

detic mass balance of the Academy of Sciences Ice Cap,

at the Academy of Sciences Ice Cap summit and the

and, in particular, on the possible factors controlling its

Golomyanny station summer surface air tempera

long-term changes and trends in climatic mass balance.

tures. On the other hand, Zhao et al. (2014) found

that the total number of melt days on Severnaya Zem

lya was strongly correlated with NCEP-NCAR re

Study site

analysis summer temperatures. For these reasons, we

have not used in our analysis the temperature data

General data for the Academy of Sciences Ice

from Golomyanny and Fedorova stations, but, in

Cap has been presented in the companion paper [19],

stead, the NCEP-NCAR reanalysis temperatures.

so we will not repeat it here. We will focus here on

Neither the precipitation data at Golomyanny and

presenting the climatic conditions of Severnaya

Fedorova stations are representative of the conditions

Zemlya, and the Academy of Sciences Ice Cap in

at the ice cap, which receives a higher amount of pre

particular, as these are most relevant for mass bal

cipitation of ~0,4 m w.e. a^-1 [21] than the amount re

ance, which is the focus of this paper. We will also

corded at Golomyanny and Fedorova stations.

 30 

F.J. Navarro et al.

An automatic weather station installed close to the

very accurate (~15 cm) where gently sloping topogra

summit of Academy of Sciences Ice Cap between May

phy is present [34]. Most observations used in our study

1999 and May 2000 provided temperature information

correspond to spring 2004 (see further details in [18]).

for the air and the shallow snow [27]. The mean an

We also used the ArcticDEM derived from high-reso

nual air temperature was -15.7 °C, whereas the average

lution submetre satellite imagery from the WorldView

temperature of the uppermost 10 m of snow/firn was

and GeoEye satellite constellations [35]. The surface

warmer at -10.2 °C, because of the latent heat released

heights retrieved from this imagery are adjusted using

by the refreezing of percolating surface meltwater. Dur

ICESat-derived altimetry as a reference [36, 37]. Ice-

ing the summer months of July and August tempera

free land surrounding the ice cap served to vertically ad

tures were commonly above the freezing point, causing

just the strips, and as a reference to check the quality of

snowmelt and a decrease in snow height [27].

the DEMs. The horizontal resolution of the strip DEM

Regarding longer-term past temperature evolu

product is 2 m, whereas that of the mosaic DEM prod

tion, an ice core drilled at the summit of the Acad

uct is 10 m. The vertical accuracy of these datasets de

emy of Sciences Ice Cap has provided a temperature

pends on the use of ground-control points as a final step

record for the last 275 years, inferred from δ¹⁸O con

for DEM vertical position refinement. When no ground

centrations in the ice core. This record shows a mini

control is available, the DEM accuracy relies on the ac

mum in 1790 followed by an increasing overall trend

curacy of the sensor’s rational polynomial coefficients,

up to present but with a double maximum in the first

and is typically in the order of 4 m [36, 37]. The DEM

half of the 20th century [28, 29]. This increasing tem

strips used for this study correspond to the years 2012,

perature trend helps explaining the role of the Kara

2013 and 2016 (see further details in [18]).

Sea as a moisture source in the area [26, 22]. It also

Ice-surface elevation change rates and associated

explains the increase in sea-salt content at low alti

mass changes. We estimated decadal-scale average sur

tudes on the ice cap, especially during warm sum

face-elevation change rates for 2004-2016 by differenc

mers [29]. The increase in moisture in the region has

ing ICESat altimetry data form 2004 and ArcticDEM

also been influenced by the decreasing trend of sea-

strips from 2016. We also calculated short-term eleva

ice cover in the Arctic beginning in the 1980s [30].

tion changes using pairs of ArcticDEM strip products

The overall picture of temperature change in the last

from 2012/2013-2016. The elevation change rates were

decades is especially critical for the Arctic region,

split into 25-m height bins using an ice-cap hypsom

with a tipping point at the beginning of the 1980s [31].

etry calculated from the ArcticDEM mosaic product.

The mass balance of the ice caps on Severnaya

Mean elevation change rate values were calculated for

Zemlya and their response to climate change has been

individual drainage basins and for increments of ice-

addressed by a set of papers by Bassford et al. [14-16].

cap hypsometry. Volume change rates were converted

For the Academy of Sciences Ice Cap in particular,

to mass loss rates (geodetic mass balance) using an ice

Moholdt et al. [32], using ICESat altimetry togeth

density of 900 kg m^-3. This assumes Sorge’s law [38],

er with older DEMs and velocities from Landsat im

i.e. that there is no changing firn thickness or density

agery, calculated the geodetic mass balance and the

through time and that all volume changes are of glacier

calving flux for various periods during the last three

ice. Two error sources were considered: the error de

decades, showing that variable ice-stream dynamics

rived from the differencing of the two datasets and, for

dominated the mass balance of the ice cap.

calculations involving ICESat data, the extrapolation

error associated to an estimation made in an area out

side of the region covered by the ICESat altimetry data.

Data and methods

The error of the elevation difference was calculated as

the square root of the sum of the squares of the mea

Ice-surface elevation data. We used surface-eleva

surement errors of the two elevation sources involved.

tion data from various sources and periods to derive

Dividing this error by the number of years between the

surface-elevation change rates and volume changes.

acquisitions considered provided the elevation change

In particular, we used ICESat elevation data from ver

rate error. The extrapolation error was estimated from

sion 34 of the GLAH06 altimetry product [33], based

the difference, within the same height bins, of the cal

on acquisitions by the Geoscience Laser Altimeter Sys

culated point-wise elevation change rates from ICESat

tem (GLAS) onboard ICESat [34]. ICESat altimetry is

altimetry and the mean elevation change rate from the

 31 

Ледники и ледниковые покровы

Table 1. Mean annual surface-elevation and mass-change rates for the main marine-terminating drainage basins of the Acade-

my of Sciences Ice Cap. Mass-change rates are calculated assuming an ice density of 900 kg m^-3.

Values were calculated from both ICESat-ArcticDEM and ArcticDEM-ArcticDEM differencing, which represent decadal (2004-

2016) and recent, shorter-term (2012/13-2016) average values, respectively. ICESat elevation changes were extrapolated hypsomet

rically. The rates for some basins during 2012/13-2016 are not given because of insufficient coverage of the WorldView images

(which are the basis for the ArcticDEM) in 2012/13

Таблица 1. Среднегодовые значения скоростей изменения высот поверхности и массы для основных ледосборных бас-

сейнов купола Академии Наук, заканчивающихся в море. Скорости изменения массы рассчитаны исходя из плотно-

сти льда 900 кг/м³.

Значения были рассчитаны по разностям ЦМР ICESat-ArcticDEM и ArcticDEM-ArcticDEM. Эти разности характеризу

ют средние изменения соответственно за более чем десятилетний период (2004-2016 гг.) и более короткий современный

период (2012/13-2016 гг.). Изменения высот ICESat экстраполировались гипсометрически. Скорости изменения высот

для некоторых бассейнов в 2012/13-2016 гг. не приведены из-за недостаточной обеспеченности космическими снимка

ми WorldView (которые служат основой для ArcticDEM) для 2012/13 г.

Surface-elevation change rate

Mass-change rate

Drainage basin

ICESat-ArcDEM

ArcDEM-ArcDEM

ICESat-ArcDEM

ArcDEM-ArcDEM

2004-2016, m a^-1

2012/13-2016, m a^-1

2004-2016, Gt a^-1

2012/13-2016, Gt a^-1

North

-0,05±0,10

-0,05±0,12

West

0,06±0,07

0,05±0,06

-0,10±0,10

-0,12±0,11

-0,06±0,07

-0,07±0,07

-0,28±0,11

-0,58±0,18

-0,10±0,04

-0,21±0,08

South

-0,20±0,13

-0,02±0,01

-1,31±0,33

-1,21±0,24

-0,33±0,08

-0,30±0,06

Southeast

-0,14±0,08

-0,05±0,03

-1,00±0,14

-0,95±0,26

-0,75±0,11

-0,71±0,17

-1,02±0,13

-0,84±0,21

-0,44±0,06

-0,36±0,10

WorldView strip DEMs. In the case of the short-term

total mass balance into climatic mass balance and fron

changes in surface elevation, which were calculated by

tal ablation. The latter term refers to the ice mass losses

differencing pairs of ArcticDEM strips, the errors in el

by calving, subaerial frontal melting and sublimation,

evation change rate were estimated by comparing two

and subaqueous frontal melting at the nearly-vertical

ArcticDEMs on ice-free land. This analysis provided an

calving fronts [39]. Subaerial frontal melting and subli

RMSE value of 0,91 m for the height differences. Final

mation can be neglected in comparison with the other

ly, the errors for the basin-wide mass change rates were

terms. Submarine melting is assumed to be small for the

calculated using error propagation.

Academy of Sciences Ice Cap, because no substantial

Climatic mass balance. Neglecting basal melt

retreat has been observed along the ice fronts of its near

ing or freezing, the mass-balance rate

for a given

ly-stagnant parts [32]. Consequently, in our case study

basin is calculated as

total frontal ablation can be considered nearly equiva

lent to calving flux or to ice discharge.

M· = B

· + D

· = ∫ b

^·dS + ∫ d

^·dp,

(1)

where is the climatic mass-balance rate (surface mass

balance plus internal balance) and is the calving flux,

Results

calculated as a surface integral of its local value , over

the area S of the glacier basin, and a line integral of the

Surface-elevation changes and associated mass

local value

, along the perimeter P of its marine-ter

changes. The calculated surface-elevation change

minating margin, respectively [39]. The calving flux

rates, together with their associated mass change

term is always negative, as it represents a rate of mass

rates (geodetic mass balance) are shown in Table 1

loss. If we know the calving flux (given in the compan

and Figs. 1-3. The surface-elevation changes, at a

ion paper [19]) and the mass-balance rate derived from

decadal scale during 2004-2016, and at a shorter-

the surface-elevation changes (calculated in this paper),

term scale during 2012/2013-2016, are similar, ex

then we can use Equation 1 to estimate the climatic

cept for Basin B. The thinning rate for Basin B during

mass balance for each basin and thus the partitioning of

the most recent period is double than that of the first

 32 

F.J. Navarro et al.

Fig. 1. Surface-elevation change

rates 2004-2016 for the Acade

my of Sciences Ice Cap derived

from ICESat-ArcticDEM differ

encing.

The background image of the ice cap

is the ArcticDEM mosaic product

Рис. 1. Темпы изменения вы

сот поверхности в 2004-2016 гг.

ледникового купола Академии

Наук, полученные на основе

разности данных ICESat-Arctic

DEM.

Фоновое изображение леднико

вого купола представляет собой

мозаику ArcticDEM

period. The decadal-scale surface-elevation change-

rate map displayed in Fig. 1 shows a general thinning

pattern for all marine-terminating basins and a state

close to balance for the land-terminating northern and

marine-terminating western drainage basins. Com

paring Fig. 1 with the surface velocity field in Fig. 2

of the companion paper [19], we note that the thin

ning is largest for the basins with ice streams drain

ing to the southeast and east (Basins BC, C and D).

Drainage Basin A, which has the slowest ice-stream

flow, shows only limited average thinning, though with

greater thinning in its upper part and thickening at

lower elevations. The thinning pattern is similar for all

fast-flowing basins. The highest thinning rates occur

where flow converges from the accumulation areas at

the heads of the major ice streams (see Figs. 2 and 3).

Mass balance. As discussed in the Methods section,

we calculated the climatic mass balance from the total

mass balance and the calving flux using Equation 1.

The total mass balance was obtained from surface-el

evation changes using the geodetic method. As we are

interested in the current climatic mass-balance, we took

the geodetic mass balance for the period 2012/13-2016.

Fig.

2. Surface-elevation change rates of Drainage Basin

However, no geodetic mass-balance data were avail

BC for 2012/13-2016, derived from ArcticDEM-Arctic

DEM strip differencing.

able for certain basins (North, West, South, South

White represents no data

east) because of the lack of coverage by WorldView

Рис. 2. Темпы изменения высот поверхности ледо-

images. For these basins, we took the geodetic mass

сборного бассейна BC за 2012/13-2016 гг., получен

balance for the period 2004-2016. We assume that

ные на основе вычисления разности ArcticDEM-

this does not imply a significant difference, because

ArcticDEM.

the changes in surface-elevation change rates between

Белым цветом показаны участки, где данные отсутствуют

 33 

Ледники и ледниковые покровы

Fig. 3. Surface elevation change rates 2012/13-2016 for basins B (a), D (b) and C (c), derived from ArcticDEM-Arc

ticDEM strip differencing.

White represents no data

Рис. 3. Темпы изменения высот поверхности в 2012/13-2016 гг. для ледосборных бассейнов B (a), D (b)

и C (c), полученные на основе вычисления разности ArcticDEM-ArcticDEM.

Белым цветом показаны участки, где данные отсутствуют

both periods were very small, almost negligible, for the

negligible, except for Basin B. Therefore, we focus

drainage basins with WorldView coverage in both pe

here on analysing, at a basin scale, the main chang

riods. The results for the geodetic mass balance, with

es in thinning rates between the two periods stud

detail by basin, are shown in Table 2. For the whole

ied by Moholdt et al. [32] (1988-2006 and 2003-

ice cap, we obtained a total geodetic mass balance

2009) and our own results. Note that our study

-1.72±0.67 Gt a^-1 (-0.31±0.12 m w.e. a^-1). Since

period 2004-2016 partly overlaps with one of the pe

the calving flux calculated in the companion paper [19]

riods (2003-2009) analysed by Moholdt et al. [32].

-1.93±0.12 Gt a^-1 (-0.35±0.02 m w.e. a^-1),

When comparing Moholdt’s data with our own data,

we get a climatic mass balance

0.21±0.68 Gt a^-1

it is important to be aware that our Basins North

(0.04±0.13 m w.e. a^-1), not significantly different from

and West are grouped together as ‘North’ in Moho

zero. The total mass balance of the ice cap is therefore

ldt et al. [32] study, while our basins South, BC and

dominated by the calving flux.

Southeast are grouped as ‘Others’ in their study.

The basins North (land-terminating) and West

(marine-terminating, but with slow flow), have re

Discussion

mained fairly stable along the whole set of peri

ods analysed by Moholdt et al. [32] and ourselves.

Evolution of the surface-elevation change rates dur-

Basin A presents in 2004-2016 thinning at its upper

ing recent decades. As mentioned in the results sec

part and thickening at lower elevations, as it did dur

tion, the changes in thinning rate between our study

ing both periods analysed by Moholdt et al. [32],

periods (2004-2016 and 2012/13-2016) have been

who indicated a surge-like elevation change pattern,

 34 

F.J. Navarro et al.

Table 2. Partition of the total mass balance (calculated by the geodetic method) into climatic mass balance and frontal ablation

for the drainage basins of the Academy of Sciences Ice Cap.

The geodetic mass balance has been derived from ArcticDEM-ArcticDEM differencing for 2012/13-2016, except for the basins

marked with an asterisk, for which ICESat-ArcticDEM differencing for 2004-2016 has been used. The frontal ablation data corre

spond to the period November 2016 - November 2017 (see the companion paper [19])

Таблица 2. Разбиение общего баланса массы (рассчитанного геодезическим методом) на климатический баланс массы

и фронтальную абляцию для ледосборных бассейнов ледникового купола Академии Наук.

Геодезический баланс массы получен на основе разности ArcticDEM-ArcticDEM за 2012/13-2016 гг., за исключением

бассейнов, отмеченных звёздочкой, для которых использовалась разность ICESat-ArcticDEM за 2004-2016 гг. Данные по

фронтальной абляции соответствуют периоду ноябрь 2016 - ноябрь 2017 (см. сопутствующую статью [19])

Drainage Basin

Gt a^-1

m w.e. a^-1

Gt a^-1

m w.e. a^-1

Gt a^-1

m w.e. a^-1

North*

-0,05

-0,04

-0,05

-0,04

West*

0,05

0,11

-0,06

-0,07

-0,11

-0,04

-0,03

-0,06

-0,21

-0,52

-0,03

-0,07

-0,18

-0,44

South*

-0,02

-0,18

0,02

0,23

-0,04

-0,46

-0,3

-1,09

0,11

0,4

-0,41

-1,49

Southeast*

-0,05

-0,13

0,03

0,08

-0,08

-0,21

-0,71

-0,86

-0,02

-0,69

-0,83

-0,36

-0,76

0,08

0,17

-0,44

-0,93

Ice cap total

-1,72

-0,31

0,21

0,04

-1,93

-0,35

in agreement with the surface velocity fields of the

riod, of -2.56±0.26 m a^-1 on average in 1988-2006,

1995 InSAR data of Dowdeswell et al. [23]. Moholdt

compared with ca. -1 m a^-1 in the two most recent

et al. [32] also noted a decrease in ice flow, and cor

periods (see Fig. 3, b and Table 3, the latter in terms

respondingly in dynamic instability, between 1988-

of mass balance). Basin D has also shown widespread

2006 and 2003-2009, indicating glacier deceleration.

thinning in all periods, but with a slowly decreasing

Our own data suggest continued deceleration during

trend, which is an indication of sustained fast flow and

the period 2004-2016, with differences in surface-

results in large cumulative thinning (see Fig. 3, c).

elevation change rates between the upper and lower

Overall, we observe a larger dynamic thinning and a

parts greater than 0.8 m a^-1 (see Fig. 1).

larger contribution to mass loss by the marine-terminat

The surface-elevation change rate in Basin B de

ing southern and eastern drainage basins for 2004-2016

creased, from -1.26±0.31 m a^-1 in 1988-2006, to

and for 2012/13-2016, in comparison with the results

-0.28±0.11 in 2004-2016 and to -0.58±0.18 m a^-1 in

of Moholdt et al. [32] for 2003-2006. This largest thin

2012/13-2016. The structure of its spatial changes (see

ning, most relevant at the zones of onset of ice-stream

Figs. 1 and 3, a) is of special interest, because it shows

flow, is an indication of dynamic instability.

a surge-like pattern, with current marked thinning in

Evolution of the mass-balance rates during recent de-

the upper part of the basin (ca. -2 m a^-1) and thick

cades. The estimates of the total mass balance of the

ening in the lower part of the ice stream (ca. 1 m a^-1).

Academy of Sciences Ice Cap during the last three de

Basins South, BC and Southeast showed a transi

cades, with detail by basin, are shown in Table 3. All

tion from a near-balance value of -0.02±0.10 m a^-1 in

mass balances were obtained by the geodetic meth

2003-2006 to thinning in 2004-2016 (surface-eleva

od, which has the limitations derived from the use of

tion change rate of -0.59±0.17 m a^-1). This transition

Sorge’s law. Possible changes in the area of the ice

is more marked if Basin BC is considered separately, as

cap, if significant, would involve a further limitation.

its surface-elevation change rate is of -1.31±0.33 m a^-1

Dowdeswell et al. [23] reported an ice-cap area of

for 2004-2016, due to the initiation of ice stream flow

5575 km², based on Landsat images from 1988. Mo

in this basin sometime between 2002 and 2016, as dis

holdt et al. [32], analysing multitemporal satellite im

cussed in the companion paper [19].

agery from Corona and Landsat satellites acquired be

Basin C presented widespread thinning during all

tween 1962 and 2010, concluded that there have been

periods, but with largest changes during the earliest pe no clear trends in the fluctuations of terminus posi

 35 

Ледники и ледниковые покровы

Table 3. Mass balance rates (geodetic mass balance) for the main drainage basins of the Academy of Sciences Ice Cap and over

different periods.

Basin «North» here groups our basins North and West, and «Others» groups our basins South, BC and Southeast. These names are

used for compatibility with Moholdt et al. [32]. The values used for computing the Ice Cap total in this study are marked with an as

terisk, i.e. we have taken the values for 2012/13-2016 and, when unavailable, those for 2004-2016. All values are given in m w.e. a^-1

except those in the last row, given in Gt a^-1

Таблица 3. Значения баланса массы (геодезический баланс массы) для основных ледосборных бассейнов ледникового

купола Академии Наук и разных периодов.

Здесь бассейн «North» включает в себя наши бассейны North и West, а бассейн «Others» - наши бассейны South, BC и

Southeast. Эти названия были использованы для возможности сравнения с данными Мохолдта с соавторами [32]. Значе

ния, используемые для вычисления общей величины Ice Cap total в данном исследовании, отмечены звёздочкой, т.е. мы

взяли значения за 2012/13-2016 гг. и, если они отсутствуют, за 2004-2016 гг. Все значения даны в метрах водного экви

валента в год, за исключением значений в последней строке, приведённых в Гт/год

This study

Moholdt et al. [32]

Drainage Basin

ICESat-ArcDEM

ArcDEM-ArcDEM

1988-2006 m w.e. a^-1

2003-2009 m w.e. a^-1

2004-2016 m w.e. a^-1

2012/13-2016 m w.e. a^-1

Basin North

0,03±0,18

0,07±0,06

0±0,08*

0,14±0,23

0,14±0,09

-0,09±0,09

-0,11±0,10*

-1,13±0,28

-0,23±0,12

-0,25±0,10

-0,52±0,16*

-2,30±0,23

-0,86±0,09

-0,90±0,13

-0,86±0,23*

-1,57±0,26

-1,11±0,11

-0,92±0,12

-0,76±0,19*

Others

-0,29±0,23

-0,02±0,09

-0,53±0,15*

Ice Cap total

-0,55±0,16

-0,19±0,05

-0,31±0,12

Ice Cap total

-3,06±0,89 Gt a^-1

-1,06±0,28 Gt a^-1

-1,72±0,67 Gt a^-1

tions of the various basins of the Academy of Scienc

(2016/17 vs. 2012/13-2016); 2) the mass balances

es Ice Cap. They calculated a total area loss of the ma

given for certain basins for 2012/13-2016 actually

rine-terminating glaciers of 5 km² during 1988-2009,

correspond to 2004-2016, due to unavailability of

including several cases of small local advance and re

WordView images for those basins in 2012/13-2016.

treat. The corresponding rate of ice-volume loss was of

Taken together, the results in Table 2 of [19] and

only 0.02 km³ a^-1, which is insignificant in terms of ice-

Table 3 of this paper indicate that the total mass bal

cap mass balance. Our own observations, using Land

ance of the ice cap is nearly equivalent to the calving

sat-7 and Sentinel-2 optical images from July 2002 and

losses, which means that the long-term climatic mass

March 2016, respectively, showed local advances and

balance has remained close to zero since 1988.

retreats of the eastern and southern marine margins of

The scarce earlier observations of climatic mass

up to ca. 1-2 km with respect to the margins of Moho

balance available for the Vavilov Ice Cap on October

ldt et al. [32], but the net change in area was negligible

Revolution Island, some 120 km to the south of the

and thus we used their same ice-cap area of 5570 km².

Academy of Sciences Ice Cap, also indicate a near-

The total mass balances shown in Table 3 are

zero average balance of -0.03 m a^-1 for the periods

similar, although with reversed sign, to those of

1975-1981 and 1986-1988 [40]. Mass-balance mod

the calving fluxes presented in Table 2 of the com

elling experiments by Bassford et al. [14], also for the

panion paper [19]. The largest difference (ca.

Vavilov Ice Cap, give a similar value of -0.02 m a^-1

0.3-0.4 Gt a^-1, for 2003-2009), is attributed to the

for the whole period 1974-1988. Although all of these

use by Moholdt et al. [32] of Basin North as an ana

estimates suggested a large interannual variability,

logue for the climatic mass balance of the whole ice

such year-to-year variations have limited interest in

cap (the slightly positive climatic mass balance of

the context of this discussion, as we only have avail

Basin North multiplied by the area of the whole ice

able average mass-balance estimates over periods of

cap accounts for this difference). The second larg

several years, up to more than a decade. Therefore, me

est difference corresponds to the most recent peri

may conclude that the climatic mass balance of the

od, and it could be attributed to two facts: 1) the pe

Academy of Sciences Ice Cap has remained close to

riods analysed in both tables are close but not equal

zero on average for the last four decades.

 36 

F.J. Navarro et al.

Possible factors controlling long-term changes and

analysis of the deep ice core drilled at the ice-cap

trends in climatic mass balance. Thinking of possi

summit in 1999-2001. Deuterium excess (the dif

ble controlling factors, summer air temperature

ference between the two stable water-isotope ratios

and precipitation seem the most evident to analyse.

δ¹⁸O and δD) in precipitation depends mainly on

Using NCEP-NCAR and ERA-Interim reanalysis

the evaporation conditions in the moisture-source

data for Novaya Zemlya and Severnaya Zemlya from

region, and to a lesser extent on the condensation

1995-2011, Zhao et al. [22] studied the influence of

temperatures. The main factors controlling the pro

summer (June-September) mean 850 hPa geopoten

cess are the relative air humidity and the sea-surface

tial height temperature on snowmelt. They analysed

temperature (SST) and, to a lesser degree, the wind

the trends of both total melt days (TMD) and melt

speed during evaporation. Based on the relationship

offset date (MOD). For Severnaya Zemlya, the tem

between deuterium excess and SST, Opel et al. [26]

perature trends during 1995-2011 were of 0.80 °C de

observed that in hemispherically warmer periods the

cade^-1 (NCEP-NCAR, p-value < 0.05) and

Academy of Sciences Ice Cap receives more pre

0.88 °C decade^-1 (ERA-Interim, p-value = 0.065).

cipitation from moisture evaporated at lower SSTs,

Zhao et al. [22] found a positive correlation between

for example due to a northward shift of the mois

mean TMD and the average June-September NCEP-

ture source. Since most precipitation on Severnaya

NCAR air temperature at 850 hPa, with the slope

Zemlya is brought by air masses moving from the

of the linear regression of 10 days °C^-1 (r = 0.843,

south and southwest, the Kara Sea is likely to be a

p-value < 0.0001). Using simple regression, they also

regional moisture source and its sea-ice cover would

found that the TMDs of Severnaya Zemlya are signif

be the main factor influencing summer and autumn

icantly anti-correlated to the Laptev Sea (r = -0.735,

evaporation. Lower sea-ice cover in the Kara Sea

p-value < 0.001) and Kara Sea (r = -0.678, p-val

would allow higher evaporation rates and enhance

ue < 0.003) September sea-ice extent. However, since

the contribution of regional moisture to precipita

sea-ice extent and glacier surface melting can co-re

tion over the Academy of Sciences Ice Cap. Moho

spond to the regional temperature increase, Zhao

ldt et al. [32] searched for some evidence of this pre

et al. [22] used additionally partial correlation analy

cipitation increase for Novaya Zemlya and Severnaya

sis to remove the large-scale influence of air tempera

Zemlya, finding a slightly higher precipitation rate in

ture on both variables. Upon removal of these effects,

2004-2009 with respect to the mean for 1980-2009,

partial correlation analysis suggested that glacier melt

especially for Novaya Zemlya. For Severnaya Zem

on Severnaya Zemlya was still statistically anti-cor

lya, its climatic mass balance close to zero suggests

related to the Laptev Sea and Kara Sea sea-ice ex

that the recent precipitation anomaly is also likely to

tent. An explanation can be that reduced offshore

be real, as it provides the most reasonable mecha

sea-ice concentration, i.e. increased open-water frac

nism to counterbalance the observed increasing melt

tion, can enhance onshore advection of sensible and

trend. In summary, the near-equilibrium climatic

latent heat fluxes [41]. However, even if long-term

mass balance of the Academy of Sciences Ice Cap

changes in summer (and annual) temperatures have

(and most generally of Servernaya Zemlya) is prob

been observed during our analysed period [18], and

ably the result of two opposing effects. On one hand,

regional sea-ice concentration has also shown a clear

sea-ice cover loss would enhance precipitation by

decreasing trend [18], these changes seem to have ex

exposing larger areas of open water to evaporation.

erted only a minor impact on the long-term climatic

On the other, these larger areas of open water would

mass balance estimates for the Academy of Sciences

allow onshore advection of heat fluxes from warm

Ice Cap, which remain close to zero. An explanation

ing mixed ocean layers, accelerating surface melt on

suggested by Zhao et al. [22] is that sea-ice reduction

the ice cap. With the climatic mass balance remain

exposes larger areas of open water in summer to evap

ing near zero, the role of the calving flux is critical in

oration and change the large-scale atmospheric circu

determining the total mass balance of the Academy

lation, which results in increased summer precipita

of Sciences Ice Cap.

tion over the Arctic [42, 43].

Total ablation and its partitioning between fron-

For the Academy of Sciences Ice Cap, the in

tal ablation and surface ablation. For the projections

fluence of sea-ice concentration on precipitation

of future contributions of glacier wastage to sea-lev

has been observed by Opel et al. [26], through their

el rise, it is of interest to know the relative contribu

 37 

Ледники и ледниковые покровы

tions of surface ablation and frontal ablation to the

0.46 m w.e. a^-1 [28], frontal ablation would have rep

total ablation. Frontal ablation is equivalent, in our

resented ~42% of the total ablation over the period

case study, to calving flux, which has been calculat

2012-2016, with the remaining ~58% corresponding

ed in the companion paper [19]. But we also need an

to surface ablation. We conclude that calving loss

estimate of surface ablation. To get it, we subtracted

es are a substantial component, in fact about half of

from our calculated climatic mass balance for 2012-

the total mass loss from the Academy of Sciences Ice

2016 (0.21±0.68 Gt a^-1; see section ‘Results’) an es

Cap. This value is higher than a previous estimate by

timate of the total accumulation over the ice cap.

Dowdeswell et al. [23] for the Academy of Scienc

This estimate of accumulation was based on the mea

es Ice Cap in 1995, of ~40%. It is also higher than

sured net accumulation at the ice-cap summit and

the available estimates for other large Arctic ice caps

its variation with altitude, as done by Dowdeswell

such as Austfonna, for which Dowdeswell et al. [49]

et al. [23], and is described below.

estimated that calving accounted for 30-40% of total

At the summit of the Academy of Sciences Ice

ablation, or Svalbard as a whole, for which Błaszczyk

Cap, analysis of an ice core detected the layers of

et al. [50] gave an estimate of 17-25%.

maximum radioactivity (in terms of Cesium¹³⁷) corre

sponding to the 1963 atmospheric nuclear tests and to

the 1986 Chernobyl event. The resulting average net

Conclusions

accumulation rates were 0.45 m w.e. a^-1 from 1963

to 1999, and 0.53 m w.e. a^-1 from 1986 to 1999 [44].

Our analysis leads to the following main conclu

Later analyses by Fritzsche et al. [28] gave an average

sions:

accumulation rate of 0.46 m w.e. a^-1 over 1956-1999

1. The average total geodetic mass balance of the

based on stable-isotope investigations. These values

ice cap during 2012-2016 was of -1.72±0.27 Gt a^-1,

are also in agreement with the mean annual net mass

which is equivalent to -0.31±0.05 m w.e. a^-1 over the

balance of 0.43-0.44 w.e. a^-1 observed by Zagoro

entire ice cap area.

dnov [45] for 1986/87 using structural-stratigraphic

2. The average climatic mass balance of the

methods, although in disagreement with the annu

ice cap during 2012-2016 (similar to that for 2004-

al-layer thickness of 0.26-0.28 m suggested by Kle-

2016), was not significantly different from zero, at

mentyev et al. [46] and used by Kotlyakov et al. [47]

0.21±0,68 Gt a^-1, or equivalently 0.04±0.13 m w.e. a^-1.

for dating the Academy of Sciences ice core drilled

This agrees with the scarce in-situ observations in the

in 1986/87. On the other hand, measurements else

region during the 1970s and 1980s, and with remote-

where in Severnaya Zemlya suggest that annual pre

sensing estimates by other authors for 1988-2006 and

cipitation decreases with altitude from 0.45 at the ice-

2003-2009. The average climatic mass balance has thus

cap summit to 0.25 m w.e. a^-1 close to sea level [48].

remained around zero during the last four decades.

Assuming, a value of 0.30 m w.e. a^-1 as average ac

3. Our estimated average total ablation (surface ab

cumulation rate over the entire ice cap, as done by

lation plus frontal ablation) over the period 2012-2016

Dowdeswell et al. [23], we obtained a total accumula

is of -3.18 Gt a^-1, of which frontal ablation (dominat

tion of 1.67 Gt a^-1. If, instead, we had used as ice-cap

ed by calving) accounts for ~54% and the remaining

averaged accumulation rate its upper bound, given by

~46% corresponds to surface ablation. Calving losses

the net accumulation rate at the ice cap summit of

are, therefore, an important contributor to the mass

0.46 m w.e. a^-1 [28], the total accumulation over the

losses from the Academy of Sciences Ice Cap.

ice cap would have been of 2.56 Gt a^-1.

4. Since the climatic mass balance has remained

Since our estimate of climatic mass-balance is

close to zero over the last four decades, in spite of re

of 0.21 Gt a^-1, the surface ablation will thus be of

gional warming, the total mass balance of the ice cap

-1.46 Gt a^-1. If we add the frontal ablation (most

has been driven mainly by calving.

ly calving) of -1.72 Gt a^-1, we get a total ablation of

-3.18 Gt a^-1. This implies that iceberg calving rep

Acknowledgments. This study has received funding

resents, on average, ~54% of the mass losses over

from the European Union’s Horizon 2020 research

2012-2016, with the remaining 46% correspond

and innovation programme under grant agreement

ing to surface ablation. If we had considered, in

No 727890 and from Agencia Estatal de Investig

stead, the upper bound for the accumulation rate of

ación under grant CTM2017-84441-R of the Spanish

 38 

F.J. Navarro et al.

Estate Plan for R & D. Support to AG by the Russian

5570 км². Используя независимую оценку фрон

Fund for Basic Research grant 18-05-60109 is also

тальной абляции за 2016-2017 гг., которая равна

acknowledged. DEMs were provided by the Polar

-1,93±0,12 Гт/год (-0,31±0,12 м вод. экв./ год),

Geospatial Center under NSF OPP awards 1043681,

получаем оценку климатического баланса массы

1559691 and 1542736.

ледникового купола, существенно не отлича

ющуюся от нуля и равную 0,21±0,68 Гт / год

(0,04±0,13 м вод. экв./год), что вполне согласу

Расширенный реферат

ется с почти нулевым средним балансом, наблю

давшимся в течение последних четырёх десяти

Определены скорости изменения высоты по

летий. Обсуждаются также возможные факторы,

верхности ледникового купола Академии Наук

которые управляют долгосрочными изменени

на о. Комсомолец (архипелаг Северная Земля в

ями и трендами климатического баланса массы,

Российской Арктике) за два периода: 2004-2016

включая температуру, осадки, сплочённость мор

и 2012/13-2016 гг. Скорости для первого пери

ских льдов, относительную влажность воздуха,

ода рассчитаны на основе разности цифровых

температуру поверхности моря и скорость ветра.

моделей высот ICESat и ArcticDEM, а для вто

Используя данные об аккумуляции, измеренной

рого периода - на основе разности двух набо

на вершине ледникового купола, и высотный гра

ров цифровых моделей высот ArcticDEM. Ис

диент аккумуляции накопления, оцениваются

ходя из этих скоростей изменения высоты

полная аккумуляция и, следовательно, полная

поверхности и предполагая, что плотность льда

абляция ледникового купола как -3,18 Гт / год.

равна 900±17 кг/м³, оценён геодезический баланс

Далее рассчитывается, в какой пропорции пол

массы купола, который был почти одинаков для

ная абляция распределяется между фронтальной

обоих периодов и составил -1,72±0,67 Гт/год, что

абляцией, в которой преобладает отёл (≈54%), и

эквивалентно потерям -0,31±0,12 м вод. экв./год

климатическим балансом массы, в основном по

на всей площади ледникового покрова, равной

верхностной абляцией (≈46%).

References

tenberg S., Bolch T., Sharp M., Ove Hagen J., van den

Broeke M., Paul F. A reconciled estimate of glacier

1. Pfeffer W., Anthony A., Bliss A., Bolch T., Cogley G., Gard-

contributions to sea level rise: 2003 to 2009. Science.

ner A., Ove Hagen J., Hock R., Kaser G., Kienholz C.,

2013, 340: 852-857. doi: 10.1126/science.1234532.

Miles E., Moholdt G., Mölg N., Paul F., Radić V., Rast-

5. Radić V., Bliss A., Beedlow C., Hock R., Miles E., Cog-

ner P., Raup B., Rich J., Sharp M., The Randolph Con-

ley G. Regional and global projections of twenty-first

sortium. The Randolph Glacier Inventory: a globally

century glacier mass changes in response to climate sce

complete inventory of glaciers. Journ. of Glaciology.

narios from global climate models. Climate Dynamics.

2014, 60: 537-552. doi: 10.3189/2014JoG13J176.

2013, 42: 37-58. doi: 10.1007/s00382-013-1719-7.

2. Huss M., Farinotti D. Distributed ice thickness and vol

6. Huss M., Hock R. A new model for global glacier change

ume of all glaciers around the globe. Journ. of Geo

and sea-level rise. Frontiers in Earth Science. 2015, 3:

phys. Research: Earth Surface. 2012, 117: 1-10. doi:

1-22. doi: 10.3389/feart.2015.00054.

10.1029/2012jf002523.

7. Moholdt G., Wouters B., Gardner A. Recent mass

3. Hartmann D., Klein Tank A., Rusticucci M., Alexan-

changes of glaciers in the Russian High Arc

der L., Brönnimann S., Charabi Y., Dentener F., Dlu-

tic. Geophys. Research Letters. 2012, 39: 1-5. doi:

gokencky E., Easterling D., Kaplan A., Soden B.,

10.1029/2012gl051466.

Thorne P., Wild M., Zhai P. Intergovernmental Panel

8. Jacob T., Wahr J., Pfeffer W., Swenson S. Recent contri

on Climate Change 2013. Observations: Atmosphere

butions of glaciers and ice caps to sea level rise. Nature.

and Surface. In: The Physical Science Basis: Working

2012, 482: 514-518. doi: 10.1038/nature10847.

Group I. Contribution to the Fifth Assessment Report

9. Matsuo K., Heki K. Current ice loss in small glacier sys

of the Intergovernmental Panel on Climate Change

tems of the Arctic islands (Iceland, Svalbard, and the

Cambridge University Press, Cambridge, United

Russian High Arctic) from satellite gravimetry. Ter

Kingdom and New York, NY, USA. 2013: 159-254.

restrial Atmospheric and Oceanic Sciences. 2013, 24:

doi: 10.1017/CBO9781107415324.008.

657-670. doi: 10.3319/tao.2013.02.22.01(tibxs).

4. Gardner A., Moholdt G., Cogley J., Wouters B., Arendt A.,

10. Svendsen J., Gataullin V., Mangerud J., Polyak L. The

Wahr J., Berthier E., Hock R., Pfeffer W., Kaser G., Lig-

glacial history of the Barents and Kara sea region. In

 39 

Ледники и ледниковые покровы

Developments in Quaternary Sciences. Elsevier, 2004:

21. Bolshiyanov D., Makeyev V. Arkhipelag Severnaya Zem-

369-378. doi: 10.1016/s1571-0866(04)80086-1.

lya: Oledeneniye, Istoriya Razvitiya Prirodnoy Sredy.

11. Carr J., Stokes C., Vieli A. Recent retreat of major

Severnaya Zemlya Archipelago: Glaciation and Histor

outlet glaciers on Novaya Zemlya, Russian Arc

ical Development of the Natural Environment. St. Pe

tic, influenced by fjord geometry and sea-ice condi

tersburg: Gidrometeoizdat, 1995: 216 p. [In Russian].

tions. Journ. of Glaciology. 2014, 60: 155-170. doi:

22. Zhao M., Ramage J., Semmens K., Obleitner F. Re

10.3189/2014jog13j122.

cent ice cap snowmelt in Russian High Arctic and

12. Melkonian A., Willis M., Pritchard M., Stewart A. Re

anti-correlation with late summer sea ice extent. En

cent changes in glacier velocities and thinning at No

vironmental Research Letters. 2014, 9: 045009. doi:

vaya Zemlya. Remote Sensing of Environment. 2016,

10.1088/1748-9326/9/4/045009.

174: 244-257. doi: 10.1016/j.rse.2015.11.001.

23. Dowdeswell J., Bassford R., Gorman M., Williams M.,

13. Carr J., Bell H., Killick R., Holt T. Exceptional retreat

Glazovsky A., Macheret Y., Shepherd A., Vasilenko Y.,

of Novaya Zemlya’s marine-terminating outlet gla

Savatyuguin L., Hubberten H., Miller H. Form and flow

ciers between 2000 and 2013. The Cryosphere. 2017, 11:

of the Academy of Sciences Ice Cap, Severnaya Zem

2149-2174. doi: 10.5194/tc-11-2149-2017.

lya, Russian High Arctic. Journ. of Geophys. Research.

14. Bassford R., Siegert M., Dowdeswell J., Oerlemans J.,

2002, 107: 1-16. doi: 10.1029/2000jb000129.

Glazovsky A., Macheret Y. Quantifying the mass balance

24. Dowdeswell J., Ove Hagen J., Björnsson H.,

of Ice Caps on Severnaya Zemlya, Russian high Arctic.

Glazovsky A., Harrison W., Holmlund P., Jania J., Ko-

I: climate and mass balance of the Vavilov Ice Cap. Arc

erner R., Lefauconnier B., Ommanney S., Thomas R.

tic, Antarctic, and Alpine Research. 2006, 38: 1-12. doi:

The mass balance of Circum-Arctic glaciers and recent

10.1657/1523-0430(2006)038[0001:qtmboi]2.0.co;2.

climate change. Quaternary Research. 1997, 48: 1-14.

15. Bassford R., Siegert M., Dowdeswell J. Quantify

doi: 10.1006/qres.1997.1900.

ing the mass balance of Ice Caps on Severnaya Zem

25. Kalnay E. and 21 others. The NCEP/NCAR 40-year

lya, Russian high Arctic. II: modeling the flow of the

reanalysis project. Bulletin of the American Me

Vavilov Ice Cap under the present climate. Arctic,

teorological Society. 1996, 77(3): 437-472. doi:

Antarctic, and Alpine Research. 2006, 38: 13-20. doi:

10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2.

10.1657/1523-0430(2006)038[0013:qtmboi]2.0.co;2.

26. Opel T., Fritzsche D., Meyer H., Schütt R., Weiler K.,

16. Bassford R., Siegert M., Dowdeswell J. Quantifying the

Ruth U., Wilhelms F., Fischer H. 115 year ice-core

mass balance of Ice Caps on Severnaya Zemlya, Rus

data from Akademii Nauk Ice Cap, Severnaya Zem

sian high Arctic. III: sensitivity of Ice Caps in Sever

lya: high-resolution record of Eurasian Arctic climate

naya Zemlya to future climate change. Arctic, Ant

change. Journ. of Glaciology. 2009, 55: 21-31. doi:

arctic, and Alpine Research. 2006, 38: 21-33. doi:

10.3189/002214309788609029.

10.1657/1523-0430(2006)038[0021:qtmboi]2.0.co;2.

27. Kuhn M. Severnaja automatic weather station data

17. Zheng W., Pritchard M., Willis M., Tepes Paul., Gour-

(Severnaja Zemlja). In: The response of Arctic ice

melen N., Benham T., Dowdeswell J. Accelerating gla

mass to climate change (ICEMASS). Third year report

cier mass loss on Franz Josef Land, Russian Arctic.

(January-December 2000). European Commission,

Remote Sensing of Environment. 2018, 211: 357-375.

Framework IV, Environment and Climate Research

doi: 10.1016/j.rse.2018.04.004.

Programme (DG XII), contract ENV4-CT970490.

18. Sánchez-Gámez P., Navarro F., Benham T., Glazovsky A.,

Oslo, University of Oslo. 2000, 7-8-7-14.

Bassford R., Dowdeswell J. Intra- and inter-annual vari

28. Fritzsche D., Schütt R., Meyer H., Miller H., Wil-

ability in dynamic discharge from the Academy of Sci

helms F., Opel T., Savatyugin L. A 275 year ice-core re

ences Ice Cap, Severnaya Zemlya, Russian Arctic, and

cord from Akademii Nauk Ice Cap, Severnaya Zemlya,

its role in modulating mass balance. Journ. of Glaciol

Russian Arctic. Annals of Glaciology. 2005, 42: 361-

ogy. 2019, 65 (253): 780-797. doi: 10.1017/jog.2019.58.

366. doi: 10.3189/172756405781812862.

19. Sánchez-Gámez P., Navarro F.J., Dowdeswell J.A., De

29. Opel T., Fritzsche D., Meyer H. Eurasian Arctic climate

Andrés E. Surface velocities and calving flux of the

over the past millennium as recorded in the Akademii

Academy of Sciences Ice Cap, Severnaya Zemlya.

Nauk ice core (Severnaya Zemlya). Climate of the Past.

Led i Sneg. Ice and Snow. 2020, 60 (1): 19-28. doi:

2013, 9: 2379-2389. doi: 10.5194/cp-9-2379-2013.

10.31857/S2076673420010020

30. Stroeve J., Serreze M., Holland M., Kay J., Malan-

20. Alexandrov E., Radionov V., Svyashchennikov P. Snow

ik J., Barrett A. The Arctic’s rapidly shrinking sea ice

cover thickness and its measurement in Barents and

cover: a research synthesis. Climatic Change. 2011, 110:

Kara seas. In: Research of climate change and interac

1005-1027. doi: 10.1007/s10584-011-0101-1.

tion processes between ocean and atmosphere in polar

31. Hansen J., Ruedy R., Sato M., Lo K. Global surface

regions. Trudy of the Arctic and Antarctic Research In

temperature change. Reviews of Geophysics. 2010, 48:

stitute: St. Petersburg, 2003, 446: 99-118. [In Russian].

RG4004. doi: 10.1029/2010rg000345.

 40 

F.J. Navarro et al.

32. Moholdt G., Heid T., Benham T., Dowdeswell J. Dy

Materialy Glyatsiologicheskikh Issledovaniy. Data of

namic instability of marine-terminating glacier ba

Glaciological Studies. 1992, 75: 35-41. [In Russian].

sins of Academy of Sciences Ice Cap, Russian High

41. Rennermalm A., Smith L., Stroeve J., Chu V. Does sea

Arctic. Annals of Glaciology. 2012, 53: 193-201. doi:

ice influence Greenland ice sheet surface-melt? En

10.3189/2012aog60a117.

vironmental Research Letters. 2009, 4: 024011. doi:

33. Zwally H.J., Schutz R., Hancock D., Dimarzio J.

10.1088/1748-9326/4/2/024011.

GLAS/ICEsat L2 Global Land Surface Altimetry

42. Serreze M., Barrett A., Stroeve J. Recent changes in

Data (HDF5), Version 34. Boulder, Colorado USA:

tropospheric water vapor over the arctic as assessed

NASA National Snow and Ice Data Center Distributed

from radiosondes and atmospheric reanalyses. Journ.

Active Archive Center. 2014. doi: 10.5067/ICESAT/

of Geophys. Research: Atmospheres. 2012, 117: 1-21.

GLAS/DATA211.

doi: 10.1029/2011jd017421.

34. Zwally H.J., Schutz B., Abdalati W., James A., Bent-

43. Francis J. The where and when of wetter and drier:

ley C., Bernner A., Bufton J., Dezio J., Hancock D.,

disappearing Arctic sea ice plays a role. Environmen

Harding D., Herring T., Minster B., Quinn K., Palm S.,

tal Research Letters. 2013, 8: 1002. doi: 10.1088/1748-

Spinhirne J., Thomas R. ICESat’s laser measurements

9326/8/4/041002.

of polar ice, atmosphere, ocean, and land. Journ. of

44. Fritzsche D., Wilhelms F., Savatyugin L., Pinglot J.,

Geodynamics. 2002, 34: 405-445. doi: 10.1016/s0264-

Meyer H., Hubberten H., Miller H. A new deep ice core

3707(02)00042-x.

from Akademii Nauk Ice Cap, Severnaya Zemlya,

35. Porter C., Morin P., Howat I., Noh M., Bates B., Pe-

Eurasian Arctic: first results. Annals of Glaciology.

terman K., Keesey S., Schlenk M., Gardiner J.,

2002, 35: 25-28. doi: 10.3189/172756402781816645.

Tomko K.,Willis M., Kelleher C., Cloutier M., Husby E.,

45. Zagorodnov V.S., Klementyev O.L., Nikiforov N.N.,

Foga S., Nakamura H., Platson M., Wethington M.,

Nikolaëv V.I., Savatyugin L.M., Sasunkevich V.A. Hy

Williamson C., Bauer G., Enos J., Arnold G., Kram-

drothermal regime and ice formation in the central

er W., Becker P., Doshi A., D'Souza C., Cummens P.,

part of the Akademiya Nauk glacier, Severnaya Zem

Laurier F., Bojesen M. ArcticDEM. Harvard Dataverse,

lya. Materialy Glyatsiologicheskikh Issledovaniy. Data of

V1. 2018. doi: 10.7910/DVN/OHHUKH.

Glaciological Studies. 1990, 70: 36-43. [In Russian].

36. Noh MJ., Howat I. Automated stereo-photogram

46. Klementyev O., Korotkov I., Nikolaev V. Glaciologi

metric DEM generation at high latitudes: surface ex

cal studies on the ice domes of Severnaya Zemlya in

traction with TIN-based search-space minimization

1987-1988. Materialy Glyatsiologicheskikh Issledovaniy.

(SETSM) validation and demonstration over glaciated

Data of Glaciological Studies. 1988, 63: 25-26. [In

regions. GIScience & Remote Sensing. 2015, 52: 198-

Russian].

217. doi: 10.1080/15481603.2015.1008621.

47. Kotlyakov V., Zagorodnov V., Nikolayev V. Drilling on

37. Noh M.J., Howat I., Porter C., Willis M., Morin P. Arctic

ice caps in the Soviet Arctic and on Svalbard and pros

Digital Elevation Models (DEMs) generated by Surface

pects of ice core treatment, in Arctic research: Advanc

Extraction from TIN-Based Search space Minimization

es and prospects. Proc. of the Conference of Arctic and

(SETSM) algorithm from RPCs-based Imagery. AGU

Nordic Countries on Coordination of Research in the

Fall Meeting Abstracts. 2016: EP24C-07.

Arctic. Leningrad, December 1988. 1990, 2: 5-18.

38. Bader H. Sorge’s law of densification of snow on high

48. Bryazgin N.N., Yunak R.I. Air Temperature and Pre

polar glaciers. Journ. of Glaciology. 1954, 2: 319-323.

cipitation on Severnaya Zemlya During Ablation and

doi: 10.3189/s0022143000025144.

Accumulation Periods. In: Geographical and Glacio

39. Cogley, J., Hock R., Rasmussen L., Arendt A., Baud-

logical Studies in Polar Countries. St. Petersburg: Gi

er A., Braithwaite R., Jansson P., Kaser G., Möller M.,

drometeoizdat, 1988: 70-81. [In Russian].

Nicholson L., Zemp M. Glossary of glacier mass bal

49. Dowdeswell J., Benham T., Strozzi T., Hagen J. Iceberg

ance and related terms. IHP-VII Technical Docu

calving flux and mass balance of the Austfonna Ice

ments in Hydrology No. 86, IACS Contribution No. 2,

Cap on Nordaustlandet, Svalbard. Journ. of Geophys.

UNESCO-IHP, Paris, 2011: 114 p. doi: 10.1017/

Research. 2008, 113 (F3). doi: 10.1029/2007jf000905.

S0032247411000805.

50. Błaszczyk M., Jania J., Hagen J. Tidewater glaciers of

40. Barkov N.I. New data on the structure and develop

Svalbard: recent changes and estimates of calving flux

ment of the Vavilov Ice Dome, Severnaya Zemlya.

es. Polish Polar Research. 2009, 30 (2): 85-142.

 41 