subtropical cyclones diabatic energy sources baroclinic energy sources adapted from fig. 9 in beven...
TRANSCRIPT
Subtropical Cyclones
DiabaticEnergy Sources
BaroclinicEnergy Sources
Adapted from Fig. 9 in Beven (2012)30th Conference on Hurricanes and Tropical Meteorology
TCs Subtropical cyclones
Frontal cyclones
• Davis (2010) methodology:– Based on Ertel potential vorticity (PV)– Formulated in terms of two PV metrics that quantify the relative
contributions of baroclinic processes and condensation heating to the evolution of individual cyclones
• Davis (2010) methodology is similar to Hart (2003) cyclone phase space diagrams
Adapted Davis (2010) Methodology
Adapted Davis (2010) Methodology
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
absolute vorticity
425 hPa
Potential temperature anomaly Length of 6° box centered on cyclone
Adapted Davis (2010) Methodology
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
425 hPa
Ertel PV anomaly
Potential temperature anomaly Length of 6° box centered on cyclone
absolute vorticity
Adapted Davis (2010) Methodology
200 hPa
925 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
500 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
PV1/PV2 : measure of the contribution of lower-tropospheric baroclinic processes relative to the contribution of condensation heating
Adapted Davis (2010) Methodology
• Additional metric introduced to diagnose upper-tropospheric dynamical processes
• Upper-troposphericdynamical processes:(upper-tropospheric PV anomaly)
Ertel PV anomaly
300 hPa
Length of 6° box centered on cyclone
500 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
500 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
Upper-troposphericdynamical processes
(PV3)
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
• Upper-troposphericdynamical processes:(upper-tropospheric PV anomaly)
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
500 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
Upper-troposphericdynamical processes
(PV3)
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
Calculated from the 0.5° Climate ForecastSystem Reanalysis
V2 dataset
Hurricane Sandy: 6° × 6° box, NHC Best Track
Pea
ks in
PV
3
PV
1/P
V2
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
PV
U
Hurricane Sandy: 10° × 10° box, NHC Best Track
Pea
ks in
PV
3
PV
1/P
V2 P
VU
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
Hurricane Sandy: 12° × 12° box, NHC Best Track
Pea
ks in
PV
3
PV
1/P
V2 P
VU
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
Hurricane Sandy: 14° × 14° box, NHC Best Track
PV
U
PV
1/P
V2
Pea
ks in
PV
3
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
Hurricane Sandy: 16° × 16° box, NHC Best Track
PV
U
PV
1/P
V2
Pea
ks in
PV
3
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
Hurricane Sandy: 18° × 18° box, NHC Best Track
PV
U
PV
1/P
V2
Pea
ks in
PV
3
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
Hurricane Sandy: 20° × 20° box, NHC Best Track
PV
U
PV
1/P
V2
Pea
ks in
PV
3
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
500 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
Upper-troposphericdynamical processes
(PV3)
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
• Upper-troposphericdynamical processes:(upper-tropospheric PV anomaly)
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
300 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
Upper-troposphericdynamical processes
(PV3)
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
• Upper-troposphericdynamical processes:(upper-tropospheric PV anomaly)
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
Hurricane Sandy: 6° × 6° box, 500 hPa, NHC Best Track
Pea
ks in
PV
3
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
PV
U
PV
1/P
V2
Pea
ks in
PV
3
22 O
ctob
er
23 O
ctob
er
24 O
ctob
er
25 O
ctob
er
26 O
ctob
er
27 O
ctob
er
28 O
ctob
er
29 O
ctob
er
30 O
ctob
er
31 O
ctob
er
Hurricane Sandy: 6° × 6° box, 300 hPa, NHC Best Track
PV
U
PV
1/P
V2
300 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
Upper-troposphericdynamical processes
(PV3)
• Lower-troposphericbaroclinic processes:(near-surface potentialtemperature anomaly)
• Midtroposphericlatent heat release:(interior PV anomaly)
• Upper-troposphericdynamical processes:(upper-tropospheric PV anomaly)
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
500 hPa
Lower-tropospheric baroclinic processes (PV1)
200 hPa
925 hPa
Adapted Davis (2010) Methodology
Midtroposphericlatent heat release
(PV2)
Upper-troposphericdynamical processes
(PV3)
PV1/PV2 : measure of the contribution of lower-troposphericbaroclinic processes relative to the contribution of condensation heating
Calculated from the 0.5° Climate ForecastSystem Reanalysis
V2 dataset