climates of the periglacial region in the late pleistocene and early holocene
DESCRIPTION
CLIMATES OF THE PERIGLACIAL REGION IN THE LATE PLEISTOCENE AND EARLY HOLOCENE. R. A. Bryson and E. J. Hopkins Center for Climatic Research University of Wisconsin- Madison. - PowerPoint PPT PresentationTRANSCRIPT
CLIMATES OF THE PERIGLACIAL CLIMATES OF THE PERIGLACIAL REGION IN THE LATE PLEISTOCENE REGION IN THE LATE PLEISTOCENE
AND EARLY HOLOCENEAND EARLY HOLOCENE
R. A. Bryson and E. J. HopkinsR. A. Bryson and E. J. Hopkins
Center for Climatic ResearchCenter for Climatic Research
University of Wisconsin- MadisonUniversity of Wisconsin- Madison
WE WILL EXPLORE THE USE OF HIGH RESOLUTION WE WILL EXPLORE THE USE OF HIGH RESOLUTION PALAEOCLIMATIC MODELS TO LOOK FOR POTENTIAL PALAEOCLIMATIC MODELS TO LOOK FOR POTENTIAL
LAKE TROUT REFUGIA DURING THE LATE PLEISTOCENE LAKE TROUT REFUGIA DURING THE LATE PLEISTOCENE AND EARLY HOLOCENEAND EARLY HOLOCENE
• SALVELINUS SALVELINUS NAMAYCUSHNAMAYCUSH CAN CAN DO VERY WELL IN DO VERY WELL IN SHALLOW COLD SHALLOW COLD WATER.WATER.
• HOW COLD?HOW COLD?• WHERE WAS IT?WHERE WAS IT?
• REFUGIA, AT REFUGIA, AT ANY TIME, HAD TO ANY TIME, HAD TO BE OUTSIDE THE BE OUTSIDE THE
GLACIAL GLACIAL BOUNDARYBOUNDARY
EITHER DEEP EITHER DEEP COLD OR COLD OR SHALLOW COLD SHALLOW COLD WATER MUST WATER MUST BE FOUNDBE FOUND
COLD WATERS IN THE PASTCOLD WATERS IN THE PAST
• HOW COLD DOES THE WATER HAVE TO BE FOR A SHALLOW WATER LAKE TROUT HABITAT ?
• MODERN CONDITIONS IN THE SOUTHERN TUNDRA SUPPORT SALMONIDS IN ABUNDANCE IN SHALLOW LAKES AND
STREAMS.
HOW COLD?HOW COLD?
THE MAXIMUM TEMPERATURE IN THIS AREA MIGHT GIVE AN APPROXIMATE TEMPERATURE THRESHHOLD FOR SHALLOW WATER REFUGIA
SURFACE WATERS IN SHALLOW LAKES AND SURFACE WATERS IN SHALLOW LAKES AND STREAMS REACH MAXIMUM TEMPERATURES STREAMS REACH MAXIMUM TEMPERATURES CLOSE TO AVERAGE AIR TEMPERATURE IN CLOSE TO AVERAGE AIR TEMPERATURE IN JULYJULY
13-15° C. APPEARS TO BE APPROPRIATEAS A MAXIMUM TEMPERATURE
Station Latitude Longitude Elevation July Temp C
Ennadai 61.13 N 100.9 W 357 m 12.8
Churchill 58.75 N 94 W 35 m 11.9
Chesterfield 63.75 N 91.83 W 15 m 8.9
Baker Lake 64.3 N 96 W 18 m 10.9
FOR MODELING PAST CLIMATES WE FOR MODELING PAST CLIMATES WE WILL USE A MACROPHYSICAL HIGH WILL USE A MACROPHYSICAL HIGH RESOLUTION MODELRESOLUTION MODEL THIS MODEL IS SITE-SPECIFIC SO THAT
WE CAN IDENTIFY SMALL REGIONS SUCH AS A FRACTION OF A STATE OR FEW COUNTIES.
IT YIELDS 200 YEAR AVERAGE MONTHLY VALUES OF CLIMATIC VARIABLES.
IT RUNS ON A DESKTOP COMPUTER AND GIVES CORRECT MODERN VALUES.
BUT DOES IT WORK?
-10000-9000
-8000-7000
-6000-5000
-4000-3000
-2000-1000
0
RADIOCARBON DATE
500
550
600
650
700
750
800
850
900
950
1000
AN
NU
AL
PR
EC
IP. f
rom
MO
DE
L m
m
750
775
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825
850
875
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925
950
975
1000
AN
NU
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PR
EC
IP. from
PO
LL
EN
mm
MODEL Pannual POLLEN Pannual 010207
MODEL VS POLLEN ANALOG COMPARISONPRECIPITATION- LILY LAKE vs GRAND MARAIS, MN
COMPARISON OF PRECIPITATION COMPARISON OF PRECIPITATION RECONSTRUCTION FROM POLLEN DATA RECONSTRUCTION FROM POLLEN DATA COMPARED TO THE MODEL FOR THE ISLE COMPARED TO THE MODEL FOR THE ISLE ROYALE REGIONROYALE REGION
THE MODEL IS CORRECT FOR THE PRESENTTHE MODEL IS CORRECT FOR THE PRESENT
-10000-9000
-8000-7000
-6000-5000
-4000-3000
-2000-1000
0
RADIOCARBON DATE
10
11
12
13
14
15
16
JU
LY T
EM
PE
RA
TU
RE
fro
m M
OD
EL
C
16
17
18
19
JU
LY T
EM
PE
RA
TU
RE
from
PO
LL
EN
C
MODEL Tjuly POLLEN Tjuly 010207
MODEL VS POLLEN ANALOG COMPARISONTEMPERATURE- LILY LAKE vs GRAND MARAIS, MN
TEMPERATURE IN THE ISLE ROYALE TEMPERATURE IN THE ISLE ROYALE REGION FROM POLLEN AND FROM THE REGION FROM POLLEN AND FROM THE MODELMODEL
THE MODEL IS CORRECT FOR THE PRESENTTHE MODEL IS CORRECT FOR THE PRESENT
-20000-18000
-16000-14000
-12000-10000
-8000-6000
-4000-2000
0
RADIOCARBON DATE BP
-10
-5
0
5
10M
EA
N A
NN
UA
L T
EM
PE
RA
TU
RE
C
10
15
20
25J
ULY
TE
MP
ER
AT
UR
E C
ANNUAL TEMP. JULY TEMP. 000824
MODELED TEMPERATURE HISTORYPRESTON, MN
THE SOUTHERN DRIFTLESS AREA WAS THE SOUTHERN DRIFTLESS AREA WAS COLD ENOUGH IN THE LATE GLACIAL COLD ENOUGH IN THE LATE GLACIAL TIMETIME
-14000 -12000 -10000 -8000 -6000 -4000 -2000 0
RADIOCARBON DATE BP
0
1000
2000
3000
4000
5000
6000
7000
AN
NU
AL
SN
OW
FA
LL
mm
000824
MODELED SNOWFALL HISTORY PRESTON, MN
BUT THERE WAS MUCH SNOWBUT THERE WAS MUCH SNOW
-20000-18000
-16000-14000
-12000-10000
-8000-6000
-4000-2000
0
RADIOCARBON DATE BP
-10
-5
0
5
10M
EA
N A
NN
UA
L T
EM
PE
RA
TU
RE
C
5
10
15
20
25J
ULY
TE
MP
ER
AT
UR
E C
ANNUAL TEMP. JULY TEMP. 000825
MODELED TEMPERATURE HISTORYEAU CLAIRE AP, WI
THE NORTHERN DRIFTLESS AREA WAS THE NORTHERN DRIFTLESS AREA WAS BETTERBETTER
-20000-18000
-16000-14000
-12000-10000
-8000-6000
-4000-2000
0
RADIOCARBON DATE BP
-6
-4
-2
0
2
4
6
8
10M
EA
N A
NN
UA
L T
EM
PE
RA
TU
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C
10
15
20
25J
ULY
TE
MP
ER
AT
UR
E C
ANNUAL TEMP. JULY TEMP. 001015
MODELED TEMPERATURE HISTORYMAUSTON, WI
IT APPEARS THAT EVEN THE DRIFTLESSIT APPEARS THAT EVEN THE DRIFTLESSAREA WAS TOO WARM BY 15000 BPAREA WAS TOO WARM BY 15000 BP
WAS DEEPER WATER AVAILABLE BY THEN?
Glacial Lake WisconsinGlacial Lake WisconsinClayton and Attig (1989)Clayton and Attig (1989)
The Region at 14,000 yr BPThe Region at 14,000 yr BP(from Illinois State Museum)(from Illinois State Museum)
The 15000-13000 BP CrunchThe 15000-13000 BP Crunch
It appears that during this interval shallow It appears that during this interval shallow waters may have been too warm for Lake waters may have been too warm for Lake Trout.Trout.
Somewhat deeper waters may have been Somewhat deeper waters may have been cold enough due to much colder winters in cold enough due to much colder winters in this interval than at present.this interval than at present.
Where were they at that time?Where were they at that time?
ConclusionConclusion
• We conclude that We conclude that Salvelinus namaycushSalvelinus namaycush could could have readily survived the Ice Age in cold surface have readily survived the Ice Age in cold surface waters, with no deep cold water available.waters, with no deep cold water available.
• Modeling periglacial climates suggests that the Modeling periglacial climates suggests that the best Late Glacial refugia may have been the best Late Glacial refugia may have been the Driftless Area.Driftless Area.
• It would appear that the transition to the It would appear that the transition to the Holocene may have been the most restricted Holocene may have been the most restricted habitat time.habitat time.
ContactsContacts
Center for Climatic ResearchCenter for Climatic Research1225 W. Dayton St.1225 W. Dayton St.Madison, WI 53706Madison, WI 53706
Reid A. BrysonReid A. [email protected]@facstaff.wisc.edu
Edward J. HopkinsEdward J. [email protected]@meteor.wisc.edu