Convective Extremes
Convective Extremes Debbie Abbs Contributions from: Tony Rafter, Mohar Chattopadhyay, Will Thurston, Sally Lavender, Todd Lane, John Allen, Bertrand Timbal, James Gilmore, ACCESS Team
Introduction
Understanding weather (thunderstorms, ECLs, coincident events Detection Model selection (importance of sampling) Sensitivity studies (importance of model physics) Downscaling for climate change applications Statistical analysis Future plans
Severe Thunderstorms (Allen) Australian
Australian-based discriminant analysis using MesoLAPS proximity soundings
Application to GCM outputs
Impact of climate change
Brooks et al (2003) 90% POD Related work: Timbal - Cool season tornadoes Abbs – Severe storm environments in Mk3.5
East Coast Lows (Timbal)
Early results show that the best performing diagnostic of ECL risk of formation (Laplacien of the geopotential height: a measure of the tropopause dip) provide similar results with high resolution ECMWF interim reanalyses and coarse resolution NCEP/NCAR reanalyses (i.e.: robust to model resolution): Location of maximum value of the Laplacien of Geop. H. when ECL are observed With ECMWF interim
With NCEP/NCAR
TC and rainfall (Lavender)
Coincident Events (Abbs)
A first step in the development of projections
Detection → Sampling (a)
(b)
(c)
(d)
(a)
(b)
(c)
(d)
Muib_echo_g
Sampling - genealogy (Chattopadhyay) Bccr_bcm2_0
Csiro_mk3_5
Giss_e_r
inmcm3
Cccma_1
echam5
hadcm3
Ipsl_cm4
Cnrm_cm3
Csiro_mk3_0
Gfdl_2_0
Gfdl_2_1
hadgem1
Ingv_echam4
Miroc_medres
Mri_cgcm2
Masson, D. and R. Knutti, 2011: Climate model genealogy. Geophys Res Letters, 38. (Published 23 April, 2011) “Strong similarities are seen between models developed at the same institution, between models sharing versions 8 of the same atmospheric component, and between successive versions of the same model.
“
Modelling studies Convection over Darwin (~1km) (Lane) focussing on the dynamics and evaluating how well the simulations represent the deepest convective events and intense precipitation
Qld Floods: Experimental 1.5 km → operations (Wang & Steinle)
ECLs (10 km) (Gilmour) Sensitivity of ECL precip to different physics in WRF
Modelling studies 2009 ECL (Thurston)
2007 Pasha Bulker ECL (Abbs)
What is responsible for the development of small scale circulations. Shear instability vs. convective instability?
High-res modelling for climate change (TCs) Maximum Wind Speed 35
Occurrence (%)
30 25 20
current
15
2070
Maximum wind speed: 1 grid value per storm
10 5 0 2.5
7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 Wind Speed (m/s)
IKE_18 Max
Integrated kinetic energy
30
Powell & Reinhold (2007)
Occurrence (%)
25 20 current
15
2070
10 5
Katerina
0 5
15
25
35
45
55
65
75
85
95 105 115
Maximum Integrated Kinetic Energy (TJ)
Measure of destructive potential Incorporates effects of storm size
Convective Extremes & Statistics (Rafter)
Return period curves
Depth-area curves
Future plans 1. 2. 3.
Adapt other N.W.P. diagnostics to climate change related research Synoptic drivers of extreme rainfall & coincident surge events – objective and seamless descriptors. New CMIP5 simulations 1. 2. 3. 4.
4.
ACCESS model 1. 2.
5.
7. 8.
ECLs (risk of formation, impact of large scale forcing on formation and genesis, impact of climate change) Application of ACCESS to downscaling of convective extremes in CMIP5 outputs
Downscaling for convective extremes 1. 2.
6.
Update projections (ECL, severe thunderstorms) Applied additional diagnostics regarding extreme weather events Extended rainfall events (across the ESB) Strong wind perpendicular to the coast
Driven with CMIP5 outputs Multi-model framework (RAMS, WRF, ACCESS …) to minimise sampling issues
Improved statistical analysis of downscaled outputs Development of projections (TCs) based on multiple analysis methods ………………….
Introduction
Understanding weather (thunderstorms, ECLs, coincident events Detection Model selection (importance of sampling) Sensitivity studies (importance of model physics) Downscaling for climate change applications Statistical analysis Future plans
Severe Thunderstorms (Allen) Australian
Australian-based discriminant analysis using MesoLAPS proximity soundings
Application to GCM outputs
Impact of climate change
Brooks et al (2003) 90% POD Related work: Timbal - Cool season tornadoes Abbs – Severe storm environments in Mk3.5
East Coast Lows (Timbal)
Early results show that the best performing diagnostic of ECL risk of formation (Laplacien of the geopotential height: a measure of the tropopause dip) provide similar results with high resolution ECMWF interim reanalyses and coarse resolution NCEP/NCAR reanalyses (i.e.: robust to model resolution): Location of maximum value of the Laplacien of Geop. H. when ECL are observed With ECMWF interim
With NCEP/NCAR
TC and rainfall (Lavender)
Coincident Events (Abbs)
A first step in the development of projections
Detection → Sampling (a)
(b)
(c)
(d)
(a)
(b)
(c)
(d)
Muib_echo_g
Sampling - genealogy (Chattopadhyay) Bccr_bcm2_0
Csiro_mk3_5
Giss_e_r
inmcm3
Cccma_1
echam5
hadcm3
Ipsl_cm4
Cnrm_cm3
Csiro_mk3_0
Gfdl_2_0
Gfdl_2_1
hadgem1
Ingv_echam4
Miroc_medres
Mri_cgcm2
Masson, D. and R. Knutti, 2011: Climate model genealogy. Geophys Res Letters, 38. (Published 23 April, 2011) “Strong similarities are seen between models developed at the same institution, between models sharing versions 8 of the same atmospheric component, and between successive versions of the same model.
“
Modelling studies Convection over Darwin (~1km) (Lane) focussing on the dynamics and evaluating how well the simulations represent the deepest convective events and intense precipitation
Qld Floods: Experimental 1.5 km → operations (Wang & Steinle)
ECLs (10 km) (Gilmour) Sensitivity of ECL precip to different physics in WRF
Modelling studies 2009 ECL (Thurston)
2007 Pasha Bulker ECL (Abbs)
What is responsible for the development of small scale circulations. Shear instability vs. convective instability?
High-res modelling for climate change (TCs) Maximum Wind Speed 35
Occurrence (%)
30 25 20
current
15
2070
Maximum wind speed: 1 grid value per storm
10 5 0 2.5
7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 Wind Speed (m/s)
IKE_18 Max
Integrated kinetic energy
30
Powell & Reinhold (2007)
Occurrence (%)
25 20 current
15
2070
10 5
Katerina
0 5
15
25
35
45
55
65
75
85
95 105 115
Maximum Integrated Kinetic Energy (TJ)
Measure of destructive potential Incorporates effects of storm size
Convective Extremes & Statistics (Rafter)
Return period curves
Depth-area curves
Future plans 1. 2. 3.
Adapt other N.W.P. diagnostics to climate change related research Synoptic drivers of extreme rainfall & coincident surge events – objective and seamless descriptors. New CMIP5 simulations 1. 2. 3. 4.
4.
ACCESS model 1. 2.
5.
7. 8.
ECLs (risk of formation, impact of large scale forcing on formation and genesis, impact of climate change) Application of ACCESS to downscaling of convective extremes in CMIP5 outputs
Downscaling for convective extremes 1. 2.
6.
Update projections (ECL, severe thunderstorms) Applied additional diagnostics regarding extreme weather events Extended rainfall events (across the ESB) Strong wind perpendicular to the coast
Driven with CMIP5 outputs Multi-model framework (RAMS, WRF, ACCESS …) to minimise sampling issues
Improved statistical analysis of downscaled outputs Development of projections (TCs) based on multiple analysis methods ………………….
