NO3− fluxes
upper inlet
NO
T
2_
L_
PM
_
O3
HN
L_
PM
NO
T
3_
L_
NO3−
1.0
PM
H
O_
ON
L_
PM
NO
T
2_
L_
PM
_
O3
HN
L_
HNO3
PM
light intensive
10.0
NO3−
L_
HNO3
O_
ON
NO2−
1.0
H
lower inlet
mixing ratio [pmol / mol]
dark intensive
10.0
HONO
mixing ratio [pmol / mol]
lower inlet
PM
PM
PM
PM
H_
H_
H_
H_
_
_
T
T
3
_
_
2
3
O
NO
NO
NO
HN
HO
PM
NO
T
3_
NO3−
PM
PM
PM
PM
H_
H_
H_
H_
_
_
T
T
3
_
_
2
3
O
NO
NO
NO
HN
HO
HNO3
NO3−
NO2−
HONO
2
1.0
NO2−
1.0
10.0
NO2−
10.0
light intensive
HONO
mixing ratio [pmol / mol]
dark intensive
HNO3
mixing ratio [pmol / mol]
upper inlet
22
HONO
Beine et al.
L_
PM
4
6
8
Figure 1. Box-and-whisker plots of the nitrogen measurements at the lower and upper inlet (lower and
upper row, respectively) during the dark and light intensive (left and right column, respectively). In the box
the middle line shows the median, the box includes 50% of the distribution, and the whiskers extend to
95% of the distribution [Systat 9, 1999].
NO3− fluxes
Beine et al.
23
40
20
10
0
-10
-20
-30
Intensive
N
HO
2
PM
2
NO
_
_
TD
PM
O
HN
3
_
_D
PM
3
NO
_
_
TD
NO3−
O
_
_D
HNO3
-50
NO2−
-40
HONO
delta (low - high) [pmol/mol]
30
dark
light
PM
Figure 2. ∆ (low – high) of nitrogen species during the two intensives. Only ∆ HNO was statistically
3
significantly different from zero. During the dark intensive the mean ∆ HNO was –2.90 pmol mol-1 (95%
3
4
6
confidence interval from –5.56 to –0.24, p=0.0356), during the light intensive ∆ HNO was –5.49 pmol
3
mol-1 (95% confidence interval from –9.39 to –1.59, p=0.0072).
NO3− fluxes
2
4
6
Ion balance: Anions - Cations [neq/m3]
Ion balance: Anions - Cations [neq/m3]
Beine et al.
200
24
200
acidic
150
150
100
100
50
50
0
0
-50
-50
Particles
alkaline
-100 -100
60
65
10570
11075
115 120 125 130 135 140
Day
of2001
Year
2001
Day
of
Year
Day of Year
2001
coarse
fine
Figure 3. Ion balance for the high line during both intensives at Ny-Ålesund: (Cl− + NO2− + Br− + NO3− +
SO42−) – (Na+ + NH4+ + K+ + Mg2+ + Ca2+) [neq m-3] for coarse (> 2.5 µm aerodynamic diameter) (blue
circles) and fine (< 2.5 µm) particles (red stars).
NO3− fluxes
Beine et al.
Surface snow stratigraphy on 4 may
27 April snowfall
3-4 may wind crust
≈ 10 cm
29 April snowfall
25
25 April snowfall
18-20 April snowfalls
Fresh-looking snow crystals
Recognizable particles
Wind packed small particles
Small rounded grains
Melt-freeze layer
Faceted crystals
2
Figure 4. Surface stratigraphy
of the snowpack near the
Amundsen mast. The total
thickness of the snowpack is
about 40 cm.
NO3− fluxes
Beine et al.
28
HNO3 flux [nmol h-1 m-2]
40
20
0
-20
-40
-60
-80
115
120 125 130 135
Day of year 2001
140
2
4
6
Figure 7. HNO3 flux above the snow surface derived from denuder measurements at 2 cm and 180 cm
above the snow surface.