Seasonal Influences upon and Long-Term Trends in the Length of the Atlantic Hurricane Season



Download 160.55 Kb.
Page3/3
Date18.10.2016
Size160.55 Kb.
#2511
1   2   3

Table 2: As in Table 1, except for TCs forming within the full Atlantic basin.




Year

SST

600 hPa relative humidity

500 hPa geopotential height

850 hPa relative vorticity

850-200 hPa vertical wind shear magnitude

Early-Starting Seasons

2012

0.04

0.09

0.21

0.18

0.21

1986

0.23

0.27

0.02

-0.01

0.30

2013

0.14

0.29

0.07

0.08

0.24

1981

0.54

0.29

0.05

0.03

0.18

2003

0.36

0.01

0.31

0.09

0.17

Late-Starting Seasons

1992

-0.36

-0.33

-0.36

-0.04

-0.34

1984

-0.26

-0.33

-0.26

-0.20

-0.24

1999

-0.14

-0.08

-0.05

-0.13

-0.27

1998

-0.47

-0.37

-0.24

-0.17

-0.35

1983

-0.47

-0.37

-0.35

-0.11

-0.28




Maximum

0.54

0.29

0.37

0.18

0.30

Minimum

-0.47

-0.37

-0.42

-0.20

-0.35

Table 3: Linear correlation coefficient, computed over the region 10°S-70°N, 150°-0°W, between the departure in the June monthly-mean field from the 1979-2014 mean June monthly-mean field and the slope of the best-fit linear regressions between the 10th percentile Atlantic TC formation date and June monthly-mean fields for the Atlantic TC seasons with the five-earliest and five-latest 10th percentile formation dates. Positive (negative) linear correlation coefficients indicate that the anomaly field in question is of like (opposite) sense to the regression field.




Year

SST

600 hPa relative humidity

500 hPa geopotential height

850 hPa relative vorticity

850-200 hPa vertical wind shear magnitude

Late-Ending Seasons

2005

0.75

0.33

0.40

0.18

0.37

2003

0.50

0.09

-0.07

0.10

-0.14

1980

-0.21

0.16

0.04

0.12

0.10

1994

-0.24

0.18

0.02

0.14

-0.17

2001

0.59

0.16

0.23

0.10

0.38

Early-Ending Seasons

1983

-0.26

-0.23

-0.14

-0.07

0.08

1997

-0.77

-0.48

-0.62

-0.28

-0.60

1993

-0.47

0.06

-0.32

-0.03

-0.51

2006

-0.29

-0.28

0.02

-0.16

-0.33

1979

-0.40

-0.25

-0.31

-0.18

-0.55




Maximum

0.75

0.38

0.44

0.18

0.68

Minimum

-0.81

-0.51

-0.62

-0.28

-0.60

Table 4: As in Table 3, except for November monthly-mean fields and the 90th percentile Atlantic TC formation date.

List of Figures

Figure 1: Formation location, as assessed utilizing National Hurricane Center “best track” data, of all Atlantic TCs forming on or prior to the 10th percentile formation date for each Atlantic TC season. For TC formation events between 1979 and 2010, the highest- probability genesis pathway determined following McTaggart-Cowan et al. (2013) is illustrated by the appropriate symbol. The genesis date within two week bins is referenced by the color given to each symbol.

Figure 2: As in Figure 1, except for Atlantic TCs forming on or after the 90th percentile formation date for each Atlantic TC season.

Figure 3: Trend, in days per year, in the 5th to 95th percentile Atlantic TC formation dates between (a) 1979-2007, (b) 1979-2006, (c) 1979-2005, (d) 1979-2004, (e) 1979-2003, (f) 1979-2002, (g) 1979-2001, and (h) 1979-2014 for TCs that formed within the Kossin (2008) subset of the full Atlantic basin. The blue line indicates the 90% confidence interval.

Figure 4: As in Figure 3, except for TCs that formed anywhere within the North Atlantic basin, for (a) 1979-2007 and (b) 1979-2014.

Figure 5: Slope of the best-fit regression line between the 10th percentile Atlantic TC formation date and June monthly-mean (a) sea surface temperature (°C), (b) 600 hPa relative humidity (%), (c) 500 hPa geopotential height (m), (d) 850 hPa relative vorticity (x10-5 s- 1), and (e) 850-200 hPa vertical wind shear magnitude (m s-1) over the domain 10°S- 70°N, 150°-0°W. A one standard deviation increase in a given monthly-mean field is associated with an n day change (shaded; positive = earlier) in the 10th percentile Atlantic TC formation date. The June monthly-mean field is contoured in each panel. Cross- hatching is utilized to identify regions where the slope of the best-fit regression line is non-zero to at least 90% (light gray), 95% (dark gray), and 99% (black) confidence.

Figure 6: As in Figure 5, except globally.

Figure 7: Standard deviation of the June monthly-mean (a) sea surface temperature (°C), (b) 600 hPa relative humidity (%), (c) 500 hPa geopotential height (m), (d) 850 hPa relative vorticity (x10-5 s-1), and (e) 850-200 hPa vertical wind shear magnitude (m s-1).

Figure 8: Slope of the best-fit regression line between the 90th percentile Atlantic TC formation date and November monthly-mean (a) sea surface temperature (°C), (b) 600 hPa relative humidity (%), (c) 500 hPa geopotential height (m), (d) 850 hPa relative vorticity (x10-5 s- 1), and (e) 850-200 hPa vertical wind shear magnitude (m s-1) over the domain 10°S- 70°N, 150°-0°W. A one standard deviation increase in a given monthly-mean field is associated with an n day change (shaded; positive = later) in the 90th percentile Atlantic TC formation date. The November monthly-mean field is contoured in each panel. Cross- hatching is utilized to identify regions where the slope of the best-fit regression line is non-zero to at least 90% (light gray), 95% (dark gray), and 99% (black) confidence.

Figure 9: As in Figure 8, except globally.

Figure 10: As in Figure 7, except for November monthly-mean fields.



Figure 1: Formation location, as assessed utilizing National Hurricane Center “best track” data, of all Atlantic TCs forming on or prior to the 10th percentile formation date for each Atlantic TC season. For TC formation events between 1979 and 2010, the highest-probability genesis pathway determined following McTaggart-Cowan et al. (2013) is illustrated by the appropriate symbol. The genesis date within two week bins is referenced by the color given to each symbol.



Figure 2: As in Figure 1, except for Atlantic TCs forming on or after the 90th percentile formation date for each Atlantic TC season.



Figure 3: Trend, in days per year, in the 5th to 95th percentile Atlantic TC formation dates between (a) 1979-2007, (b) 1979-2006, (c) 1979-2005, (d) 1979-2004, (e) 1979-2003, (f) 1979-2002, (g) 1979-2001, and (h) 1979-2014 for TCs that formed within the Kossin (2008) subset of the full Atlantic basin. The blue line indicates the 90% confidence interval.



Figure 4: As in Figure 3, except for TCs that formed anywhere within the North Atlantic basin, for (a) 1979-2007 and (b) 1979-2014.



Figure 5: Slope of the best-fit regression line between the 10th percentile Atlantic TC formation date and June monthly-mean (a) sea surface temperature (°C), (b) 600 hPa relative humidity (%), (c) 500 hPa geopotential height (m), (d) 850 hPa relative vorticity (x10-5 s-1), and (e) 850-200 hPa vertical wind shear magnitude (m s-1) over the domain 10°S-70°N, 150°-0°W. A one standard deviation increase in a given monthly-mean field is associated with an n day change (shaded; positive = earlier) in the 10th percentile Atlantic TC formation date. The June monthly-mean field is contoured in each panel. Cross-hatching is utilized to identify regions where the slope of the best-fit regression line is non-zero to at least 90% (light gray), 95% (dark gray), and 99% (black) confidence.



Figure 6: As in Figure 5, except globally.



Figure 7: Standard deviation of the June monthly-mean (a) sea surface temperature (°C), (b) 600 hPa relative humidity (%), (c) 500 hPa geopotential height (m), (d) 850 hPa relative vorticity (x10-5 s-1), and (e) 850-200 hPa vertical wind shear magnitude (m s-1).



Figure 8: Slope of the best-fit regression line between the 90th percentile Atlantic TC formation date and November monthly-mean (a) sea surface temperature (°C), (b) 600 hPa relative humidity (%), (c) 500 hPa geopotential height (m), (d) 850 hPa relative vorticity (x10-5 s-1), and (e) 850-200 hPa vertical wind shear magnitude (m s-1) over the domain 10°S-70°N, 150°-0°W. A one standard deviation increase in a given monthly-mean field is associated with an n day change (shaded; positive = later) in the 90th percentile Atlantic TC formation date. The November monthly-mean field is contoured in each panel. Cross-hatching is utilized to identify regions where the slope of the best-fit regression line is non-zero to at least 90% (light gray), 95% (dark gray), and 99% (black) confidence.



Figure 9: As in Figure 8, except globally.



Figure 10: As in Figure 7, except for November monthly-mean fields.

+Corresponding Author: Dr. Clark Evans, Atmospheric Science Program, Dept. of Mathematical Sciences, University of Wisconsin-Milwaukee, P. O. Box 413, Milwaukee, WI 53201. E-mail: evans36@uwm.edu.



Download 160.55 Kb.

Share with your friends:
1   2   3




The database is protected by copyright ©ininet.org 2024
send message

    Main page