central guam mountains after a major brushfire
DESCRIPTION
The Monsoon Circulation, Typhoon Activity, and Island Rainfall in the Western North Pacific During the Past 50 Years: Recurring Patterns and Extreme Events Mark A. Lander Water and Environmental Research Institute of the Western Pacific. Central Guam mountains after a major brushfire. - PowerPoint PPT PresentationTRANSCRIPT
The Monsoon Circulation, Typhoon Activity, and Island Rainfall in the Western North Pacific During the Past 50
Years: Recurring Patterns and Extreme Events
Mark A. Lander
Water and Environmental Research Institute of the Western Pacific
Central Guam mountains after amajor brushfire.
U
Pohnpei locator maps showing world setting and Pohnpei Island with Municipalities.
Climate of Micronesia
Climate Change?Who ya gonna believe? Me, or your own eyes? *
My own rules of thumb: Warwick Rhode Island 1960s, 1970s
First touch of frost: Last week of September
First hard freeze: Last week of October
First day max temp < freezing: Last week of November
These events now occur 2 or 3 weeks later !!
* Groucho Marx
Commonly cited recent climate anomalies
Climate change during my lifetime
Global Cooling
Global Warming
Climate Variability in USAPI during the past 50 years
• Very large year-to-year changes Annual Rainfall on Guam 50 inches to 150 inches
• Tropical Cyclones WNP Basin annual number: 20 to 40!
• ENSO
• Monsoon flow pattern
Weather makers in USAPI
• Tropical Cyclones• Monsoon trough• TUTT/TUTT Cells• ENSO• Mesoscale Convective Systems
If you’re going to change the climate of Micronesia you have to change the climate of these !
Climate of Pacific Islands1500 years BP to now
(MWP through LIA to current)
Problems:• No direct measurements, none that go
back more than 100 years (50, at best in many locations)!
• Proxy records conflicting, and yield some almost inexplicable local climate and climate changes (e.g., Washington Island).
Question for Group
• Can one use very recent global temperature behavior as proxy for larger and longer transitions: e.g., MWP to LIA?
-- Investigate positions of ITCZ and rainfall on Washington Island before, during and after the “Time Magazine Ice Age”
-- 1988 very cold La Nina-related cold water
What did it do to ITCZ?
9000
10000
1876
1880
1884
1888
1892
1896
1900
1904
1908
1912
1916
1920
1924
1928
1932
1936
1940
1944
1948
1952
1956
1960
1964
1968
1972
1976
1980
1984
1988
1992
1996
2000
2004
-50
-40
-30
-20
-10
0
10
20
30
40
Southern Oscillation Index
1988 had very cold equatorial waters. Check position of ITCZ
1988
MONSOON
Summer Monsoonof the western North
Pacific
Normal surface flow pattern(black = westerly)VS 1997(dashed-line filled = westerly).
Summer Monsoon
Surface wind flow, August 1997
Palau
Strongest Westerly Wind Burst ever Observed ! (December 1996)
Normal Monsoon
40 N
30 N
20 N
10 N
EQ100 E 140 E 160 E 180120 E
Guam
Saipan
Pohnpei Majuro
Reverse Oriented Monsoon Trough
40 N
30 N
20 N
10 N
EQ100 E 140 E 160 E 180120 E
12
3Guam
Saipan
Pohnpei Majuro
Next Trough Develops
40 N
30 N
20 N
10 N
EQ100 E 140 E 160 E 180120 E
Guam
Saipan
Pohnpei Majuro
Permian Surface winds and rainfall
Cold Tongue
The MJO
C
C
EQ
21
Put the only heat source of the entire planet over the Maritime Continenent:Easterly winds would extendacross the whole Pacific, Atlanticand to East Africa. Westerlieswould extend across the Indian Ocean.
GUAM
TC CRAIGTC ERICA
TC ESETA
SHEAR LINE
NW MONSOON
W
GMS IR 00 UTC 22 OCT
TDTD
KetsanaParma
TD??
GMS IR 00 UTC 22 OCT
TDTD
KetsanaParma
TD??Reverse-orientedMonsoon Trough
W
Super Typhoon Paka (December 1997)
Majuro
When low latitudewinds go westerly, clouds and rain are found in maxwest wind band andin associated TCs.
W.I.
Question for Group:
• How much was this flow pattern changed by past 1500-year climate changes and how much can it be changed by anticipated global warming?– Location of STR, monsoon trough, TUTT, typhoon
tracks
– ENSO effects
– Large-scale features similar even in Permian!!
Question for Group:
• Washington Island bone dry?– There would almost have to be a cold tongue (i.e., not major El Nino like all the time).
– Christmas Island also dry?• Then ITCZ must either be most of the time in the Southern
Hemisphere, or ITCZ is pushed to the north of W.I. for much of the year. (check on 1988 – a year with an extensive cold tongue).
– Meteorological “Equator” currently at 7 North!!– Palau now dry only because of El Nino (+1) and during
typical September when the monsoon trough moves well to the north.
ENSO
Micronesia Rainfall in a Warmer World
1998 HNL conference:Reduction in mean annual rainfall from shift in ENSO * More El Nino Like most of the time * More Large El Nino’s
Southern Oscillation IndexRunning Sum
-120
-100
-80
-60
-40
-20
0
20
40
1866
1870
1874
1878
1882
1886
1890
1894
1898
1902
1906
1910
1914
1918
1922
1926
1930
1934
1938
1942
1946
1950
1954
1958
1962
1966
1970
1974
1978
1982
1986
1990
1994
1998
2002
2006
July 1976
Catastrophic floodingIn the Marquesas
Micronesia-wideSevere Drought
Eastern MicronesiaDeadly Typhoon
1998
1992
1983
ENSO Time Series (SOI)
-150
-100
-50
0
50
1866
1870
1874
1878
1882
1886
1890
1894
1898
1902
1906
1910
1914
1918
1922
1926
1930
1934
1938
1942
1946
1950
1954
1958
1962
1966
1970
1974
1978
1982
1986
1990
1994
1998
2002
RED = Running Sum of time series: 0.4*(month-1) + 0.3*(month-2) + 0.1*(month-3) + RANDOM NUMBER
DARK BLUE = RUNNING SUM OF SOI 1866-2002
Pacific Interannual and Interdecadal Variability
• There is ONLY ENSO. Time series is autoregressive (several months)
with stochastic forcing. Spectral Peak at ~ 2.6 years.
• Pacific Decadal Oscillation is reddened ENSO. Time series and fields are similar, but with
longer memory because of mid-latitude mixed-layer deepening.
PDO is reddened ENSO
Question for Group:
• Has ENSO been affected by climate changes in the past 1500 years?
Frequency, strength, character
• ENSO affects almost everything in USAPI: Tropical cyclone distribution, rainfall, sea level, monsoon trough
position, and extreme events of weather elements.
1998 Climate workshop East-West Center
Consider ENSO in a warmer world:
More frequent strong El Nino’s like 1982-83 and 1997-98?
or
Climate more El Nino-like all the time?
Question: Is this the model for the past 1500 years?(MWP and LIA ??)
ENSO
RAINFALL
Micronesia Rainfall by Hour
GUAM ANNUAL RAIN
NOTE: POST-EL NINO YEARS IN RED
0
20
40
60
80
100
120
140
160
1950
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
NOTE: RED INDICATES POST EL NINO YEARS
NORMAL
0
20
40
60
80
100
120
140
160
180
200
1953
1955
1957
1959
1961
1963
1965
1967
1969
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
AN
NU
AL
RA
IN (
INC
HE
S)
KOROR ANNUAL RAIN
MAJURO ANNUAL RAIN
0
20
40
60
80
100
120
140
160
180
200
1955
1957
1959
1961
1963
1965
1967
1969
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
NORMAL
NOTE: POST-EL NINO YEARS IN REDPOHNPEI ANNUAL RAIN
NOTE: POST-EL NINO YEARS IN RED
0
50
100
150
200
250
1953
1955
1957
1959
1961
1963
1965
1967
1969
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
1992
Guam Rainfall VS Water Table
-60
-40
-20
0
20
40
1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002
-15.00
-10.00
-5.00
0.00
5.00
10.00
15.00
20.00
Integrated Guam Rainfall Anomaly (Red) VSObserved A20 Wellhead (Blue)
LONG-TERM SURPLUSES AND DEFICITS (Pohnpei)
-120
-70
-20
30
80
130
180
1953
1955
1957
1959
1961
1963
1965
1967
1969
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
2001
JANUARY OF POST-EL NINO YEAR
Pohnpei Rainfall
-6000
-4000
-2000
0
2000
4000
6000
8000
1926
1928
1930
1932
1934
1936
1938
1940
1942
1944
1946
1948
1950
1952
1954
1956
1958
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
DR
Y
--
----
W
ET
-20
-10
0
10
20
30
40
Manoa Rainfall 1921-2007 Running Accumulation
Extreme Value Analysis
0.1
0.3
0.2
0.50.4
0.6
0.8
1.0
6.05.04.0
3.0
2.0
15.0
10.0
8.0
5 10 20 30 40 50 60 2 3 4 5 6 8 1012 18 24IN MINUTES IN HOURS
DURATION
Saipan Int. Airport with
consideration of typhoons
5
20
50
100 Pongsonaon Guam
10
Pohnpeiwet day
Oct 29, 2003
INCHES
PER
HOUR
IDF chart of selected return periods at the SIA (blue dots connected by blue dashed lines). Because the cause of the extreme events is typhoons, this curve may be considered applicable for all of Saipan. The intensity-duration values measured during Typhoon Pongsona on Guam (red dots connected by red dotted line) are shown. Also, the highest Intensity-duration values measured by a newly installed rain gauge network on Pohnpei have been plotted (green dots connected by green dotted line). Without typhoons, the return-periods at all durations would be much lower.
HEAVY RAINFALL IN A TYPHOON
0
5
10
15
20
25
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
LOCAL TIME (08 DEC 2002)
RA
INF
AL
L (
INC
HE
S)
PONGSONA RAINFALL TIME SERIESAT ANDERSEN AFB
EYE PASSAGE
Max = 175 mm/hr
Questions for Group:
• How have past 1500-year climate changes affected rainfall in USAPI?
• Can USAPI extreme rainfall events be affected by global climate changes such as MWP, LIA and anticipated AGW?
• Do typhoons produce the highest rain rates at all intervals: 15 minute to 24 hour?
Questions for Group:
• Is the overall rainfall in the tropics heavier in a warmer world? *
– * I have outstanding bet with Bob Livezy regarding Singapore rainfall over the past 50 years.
• Or, are only the values of extreme rainfall elevated in a warmer environment?
– e.g., Trenberth’s claim of Katrina 7% more rain because of AGW
– Every cloud affected? Or just typhoons? (The Katrina Effect)
TYPHOONS
SUNDAY MORNING, 8 December 2002
Guam
Rota
TinianWMO International Workshop on
Tropical CycloneLandfall
Processes. Macao, China. (21- 25 March
2005)
M. LanderSlide 16
WMO International Workshop on
Tropical CycloneLandfall
Processes. Macao, China. (21- 25 March
2005)
M. LanderSlide 9
Western North Pacific Tropical Cyclone Variability
-25
-15
-5
5
15
25
35
-25
-15
-5
5
15
25
35
TS + TY
TY
JTWC Running sum of annual anomalies
1960 1970 1980 1990 2000
Active
Active
QuietQuiet
145 E
18 N
15 N
12 N
1970-79
145 E
18 N
15 N
12 N
1980-89
18 N
15 N
12 N
145 E1990-99
145 E
18 N
15 N
12 N
1970-99
Tropical Cyclone Locations
More?
Anatahan
Saipan
Tinian
Rota
Guam
140 E 150 E145 E
15 N
10 N
15 N
10 N
140 E 145 E 150 E
20
20
30
40
50
60
7080
90
100
100
90
80
70
7080 80
7060
5040
40
30
40
50
Contours (at intervals of 10) show the number of tropical storms and typhoons per 100-years expected to pass within 75 nautical miles from any map location. Analysis is based on the years 1945-97. Chart adapted from Guard, et al. (1999). Note that on this fine scale, Guam appears to have a slightly higher risk of a tropical storm or a typhoon than Saipan (60 per 100-years, versus 50 per 100-years).
PEAC Typhoon Risk Assessment
EQ
10N
20N
30N
100E 120E 140E 160E 180
"El Nino Box"
19981997
INCREASED Threat for Marshalls and GuamNEUTRAL for CHUUK (End of El Nino Year)
CHUUK
Majuro
YAP Guam
Western North Pacific Tropical Cyclone Distribution*
40 N
30 N
20 N
10 N
EQ100 E 140 E 160 E 180120 E
1
1
1
2
2
3
3
4
5
Guam
Saipan
* Tropical cyclones per 5 x 5 square per year
2007 Tropical Cyclone Distribution
EQ
10N
20N
30N
100E 120E 140E 160E 180
"El Nino Box"
20071997
Guam
Guam/CNMI For all of June, July, August and September, the weather on Guam has been rather tranquil. Winds have been very light (easterly for the most part, with a few periods of light westerly wind flow), only one tropical cyclone (Man-Yi) adversely affected the island (it generated near-gale winds for one day in early July), and there have been no extreme island-wide heavy rainfall events. In association with La Niña, monsoon southwest winds remained mostly to the west of Guam, and tropical cyclone development was also pushed to the west and north of Guam. In an environment of light wind, rainfall was produced on-island by short-lived (6-12 hr) mesoscale convective systems, and by isolated (mostly daytime) thunderstorms that affected only parts of the island on any given day. Daytime thunderstorms have produced isolated heavy rainfall totals near 2 or 3 inches in a few hours at some locations, however, over the course of a month, rainfall amounts in this weather pattern tend to average near to slightly below normal. …..
(PEAC 4th QTR 2007 Newsletter)
2007 Tranquility
Questions for Group:
• How have past 1500-year climate changes affected typhoon climate in USAPI?
• More typhoons in a warmer world?• More very intense typhoons (overall) or
as a higher proportion of all typhoons in a warmer world? (vice versa for a colder world? LIA ??)– Note 2007 Tranquility
• Track changes?
Final Questions for Group:
• How have past 1500-year climate changes affected typhoon climate in USAPI?
• Can we investigate this by studying changes to rainfall, typhoons, and extreme events during observed large departures from average climate during the past 50 to 100 years? Extrapolate to MWP and LIA?
Photo Courtesy of Roger Edson
Smoke from fuel fire
Sand from overwash
ENDSunset on Guam Post TY Pongsona