climatology and variability of the ice-ocean-atmosphere ...€¦ · climatology and variability of...
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Climatology and variability of the ice-ocean-atmosphere-terrestrial system on the Yamal
Uma Bhatt1, Donald A. Walker2, Martha K. Raynolds2, Howard E. Epstein4, Gensuo Jia5, Josefino C. Comiso6 Jorge E Pinzon6, Compton J. Tucker6
1Geophysical Institute & Dept. Atmospheric Sciences at U. Alaska Fairbanks (UAF), 2Institute of Arctic Biology at UAF, 4Dept. of Env. Sci. at University of VA, 5CAS, Beijing China, 6NASA Goddard Space Flight Center
Poster presented at the LCLUC Science Team Meeting, Bethesda, MD, 20-22 April 2010
Motivation and Methods Goal: Investigate the role of seasonality in current
understanding of tundra-climate relationships
New GIMMS-NDVI3g for the Arctic
Technical Information•The GIMMS data set uses a histogram matching approach with periodogram parameter regularization•To ensure spatial coherence, temporal consistency among the AVHRR NDVI record and ensure continuity for the coming missions: National Polar Orbiting Operational Environmental Satellite System (NPOESS) and Preparatory project (NPP).•An apparent 72N spatial discontinuity in the previous GIMMS-NDVIg product was fixed by using histogram matching from:
•SeaWIFS instead of SPOT which doesn't collect data above 720N•May-September instead of January-December to avoid terminator effects leaking into the parameters.•An integration of NOAA-18 and NOAA-17 NDVI data.
•NDVI3g is ready for distribution for all continents (for more information contact [email protected]).
NOAA 7 NOAA 9 NOAA 11 NOAA 14 NOAA 16
NOAA 17/18
NO9
SeaWIFS!
SPOT!Terra/Aqua
NPP
81 | 83 | 85 87 | 89 | 91 | | 93 | 95 | | 99 | 01 | 97 | 05 03 07 09 | | | 11
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NDVIg NDVI3g
NPOESS
Data: Use 25 km resolution SSMI passive microwave Bootstrap Sea Ice Concentration (SIC), AVHRR Surface Temperature (Ts), and new GIMMS
NDVI3g for the Arctic over the 1982-2008 period. Methods: Standard climate
trend and correlation analysis techniques applied to regional (Modified Treshnikov basins)
time series of Maximum NDVI, Time Integrated NDVI,
Summer Warmth Index, and sea ice concentration
constructed using data within 50-km of Arctic coastlines
(ocean & land) . Map delineating regions used in this research. Color highlights 50-km coastal regions.
NDVI = (NIR-R)/(NIR+R) NIR: spectral reflectance in near-infrared band
(0.725-1.1 μm) & R: red chlorophyll absorbing portion of spectrum (0.58-0.68 μm)
AcknowledgementsThis study was supported by grants NSF ARC-0531180, NASA NNG6NE00A, NSF ANS-0732885, NSF ARC-0902175, NASA Land Cover Land Use Change on the Yamal Peninsula.
References• Pinzon, J. E., E. Pak, C.J. Tucker, 2009 (submitted), A revised AVHRR 8-km NDVI Data Set -
Compatibility with MODIS and SPOT Vegetation NDVI Data, American Geophysical Union EOS Transactions.
• U.S. Bhatt, D.A. Walker, M.K. Raynolds, J.C. Comiso, H.E. Epstein, G.Jia, R. Gens, J.E. Pinzon, C.J. Tucker, C.E. Tweedie, and P.J. Webber, 2010 (in revision): Circumpolar Arctic tundra vegetation change is linked to sea-ice decline, Earth Interactions.
Contrast N. America and Eurasia
[Bhatt et al., 2010]
-60 -40 -20 0 20 40 60 80
-60 -40 -20 0 20 40 60 80
W. BeringW. ChukchiE. Siberian
LaptevE. Kara
W. KaraBarents
Grnlnd SeaDavis Str.Baffin BayCan. Arch.
BeaufortE. Chukchi
E. BeringEurasia
N. AmericaN. Hemis.
SWI Trend
Sea Ice Trend
Percentage Change (1982-2008)
Sea Ice Area
Summer Warmth Index
***** *** ***
*** * *** * * **
-8 -4 0 4 8 12 16
-8 -4 0 4 8 12 16
W. BeringW. ChukchiE. Siberian
LaptevE. Kara
W. KaraBarents
Grnlnd SeaDavis Str.Baffin BayCan. Arch.
BeaufortE. Chukchi
E. BeringEurasia
N. AmericaN. Hemis.
MaxNDVI
TI-NDVI
Percentage Change (1982-2008)Time Integrated NDVI
Maximum NDVI
*
**
****** * *
•Trends are larger in N. America•Variability is larger in Eurasia •North Slope: Largest magnitude NDVI & SWI increases•High Arctic: Largest % increases in MaxNDVI and SWI•Bering/W.Chukchi: NDVI decline•Eurasia: small summer warming
N. Hemisphere
-25% (3.2)24% (1.4) 2% (0.075)5% (0.010)
Eurasia
-28% (5.7)16% (1.9)
2% (0.102)2% (0.128)
N. America
-23% (3.4)30% (1.6)
3% (0.073)9% (0.010)
0
0.25
0.5
0.75
0
2
4
6
1985 1990 1995 2000 2005
Max
ND
VI TI-N
DV
I
0
0.25
0.5
0.75
0
2
4
6
1985 1990 1995 2000 2005
Max
ND
VI TI-N
DV
I
0
0.25
0.5
0.75
0
2
4
6
1985 1990 1995 2000 2005
Max
ND
VI TI-N
DV
I
0
10
20
30
40
50 0
20
40
60
80
1001985 1990 1995 2000 2005
Sum
mer
War
mth
Inde
x (˚
C m
onth
)
Sea Ice C
oncentration (%)
0
10
20
30
40
50 0
20
40
60
80
1001985 1990 1995 2000 2005
Sum
mer
War
mth
Inde
x (˚
C m
onth
)
Sea Ice C
oncentration (%)
0
10
20
30
40
50 0
20
40
60
80
1001985 1990 1995 2000 2005
Sum
mer
War
mth
Inde
x (˚
C m
onth
)
Sea Ice C
oncentration (%)
50-km region
0
20
40
60
80
100
1980 1985 1990 1995 2000 2005 2010
14-20May
28May-3Jun
11-17Jun
25Jun-1Jul
9-15Jul
16-22Jul
23-29Jul
30Jul-5Aug
6-12Aug
20-26AugYear
50-km and full tundra domains similar
0
10
20
30
40
50 0
20
40
60
80
1001985 1990 1995 2000 2005
Sum
mer
War
mth
Inde
x (˚
C m
onth
)
Sea Ice C
oncentration (%)
-38% 4.2% 0
0.25
0.5
0.75
0
2
4
6
1985 1990 1995 2000 2005
Max
ND
VI TI-N
DVI
0.9% 2.1%
•Sea ice (blue) shows significant decreases.
•SWI (red) and NDVI (greens) display very small positive trend.
-60
-50
-40
-30
-20
-10
0
10
20
-6
-4
-2
0
2
4
6
8
10
jan0
4ja
n18
feb0
1fe
b15
mar
01m
ar15
mar
29ap
r12
apr2
6m
ay10
may
24ju
n07
jun2
1ju
l05
jul1
9au
g02
aug1
6au
g30
sep1
3se
p27
oct1
1oc
t25
nov0
8no
v22
dec0
6de
c20
Yamal Land Ts 50kmTs std trend
*
0
20
40
60
80
100
120
140
160 -40
-20
0
20
40
60
80
jan04
jan18
feb01
feb15
mar01
mar15
mar29
apr12
apr26
may10
may24
jun07
jun21
jul05
jul19
aug02
aug16
aug30
sep13
sep27
oct11
oct25
nov08
nov22
dec06
dec20
Yamal 50km icemean std trend
* ** ** * ** ** *
MaxNDVI Biweekly April-October
Sea Ice weekly
Surface Temp weekly
-0.4
-0.2
0
0.2
0.4
0.6
0.8
0
0.2
0.4
0.6
7_apr_a
8_apr_b
9_may_a
10_m
ay_b
11_jun_a
12_jun_b
13_jul_a
14_jul_b
15_aug_a
16_aug_b
17_sep_a
18_sep_b
19_oct_a
20_oct_b
YamalYamal-std
Yamal-trend
* * * * * *
Weekly Sea Ice Trends & Variability
Weekly Ts Trends & Variability
Bi-weekly NDVI Trends & Variability
0
200
400
600
800
1000
jan1
8
mar
01
apr1
2
may
24
jul0
5
aug1
6
sep2
7
nov0
8
dec2
0
80s var90s var
00s varYamal
0
20
40
60
80
100
jan1
8
mar
01
apr1
2
may
24
jul0
5
aug1
6
sep2
7
nov0
8
dec2
0
80s mean
90s mean
00s mean
Yamal
•Ice decreasing trends in spring and fall•90’s spring earlier & 00s spring earlier and fall later•90’s variability was higher from Mar-Aug & Sep-Nov
0
10
20
30
40
50
60
jan1
8
mar
01
apr1
2
may
24
jul0
5
aug1
6
sep2
7
nov0
8
dec2
0
Var 80sVar 90s
Var00sYamal
-30
-20
-10
0
10
20
jan1
8
mar
01
apr1
2
may
24
jul0
5
aug1
6
sep2
7
nov0
8
dec2
0
80savg 90s avg 00'sYamal
•Ts is highly variable • 90’s spring was warmer•90’s variability was higher from Feb-Jul
0
100
200
300
400
500
600
1_ja
n_a
3_fe
b_a
5_m
ar_a
7_ap
r_a
9_m
ay_a
11_j
un_a
13_j
ul_a
15_a
ug_a
17_s
ep_a
19_o
ct_a
21_n
ov_a
23_d
ec_a
Var*10^5 80s
Var *10^5 90s
Var*10^5 00s
Yamal
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
1_jan_a
3_feb_a
5_mar_a
7_apr_a
9_may_a
11_jun_a
13_jul_a
15_aug_a
17_sep_a
19_oct_a
21_nov_a
23_dec_a
80s
90s
00s
Yamal
•NDVI increase primarily in spring.• 00’s spring slightly earlier green up, • 90’s variability was higher from May-Aug
Main Findings• Greening has not changed much on Yamal
• Land temperatures have warmed slightly in fall and even cooled in spring
• Sea ice shows significant declines with earlier melt and later freeze up.
• On a weekly (biweekly) time scale the 1990s had the most variability (El Niño and Pinatubo?)
Regional Trends
Decadal Means Decadal Variance
Decadal Means Decadal Variance
Decadal Means Decadal Variance