Quantifying the Role of Tropospheric Relative Humidity on the Development of Tropical Cyclones

Transcription

1 Quantifying the Role of Tropospheric Relative Humidity on the Development of Tropical Cyclones 1 R., 2 B. Ríos-Berríos Tang and S. S. 1University of Puerto Rico at Mayagüez 1Significant Opportunities in Atmospheric Research and Science 2 (SOARS) protégé, National Center for Atmospheric Research, 3University of Miami Image credit: NOAA/ Environmental Visualization Lab. 3 Chen

2 Why do we need to better understand TC development?

3 Why do we need to better understand TC development? One day later

4 Scope We are trying to understand how the tropospheric relative humidity affects the processes leading to TC development. A few studies had been conducted to address this issue: - Bister and Emanuel (1997) - Nolan (2007) - Ortt and Chen (2011) The sensitivities of a forming TC on tropospheric moisture has not been quantified in detail in any of the previous studies.

5 Methods Approach Idealized 2-D simulations with different initial moisture environments Calculation of efficiencies and budgets Comparison with 3-D realtime forecasts Experimental design Axisymmetric Simplified Pseudoadiabatic Entropy Conserving Hurricane (ASPECH) model Advanced Research Weather Research and Forecasting (ARW) model

6 Methods Approach Idealized 2-D simulations with different initial moisture environments Calculation of efficiencies and budgets Comparison with 3-D realtime forecasts Experimental design Axisymmetric Simplified Pseudoadiabatic Entropy Conserving Hurricane (ASPECH) model Advanced Research Weather Research and Forecasting (ARW) model

7 Methods Initial vortex Initial sounding for case RH = 60% T Td

8 Results 100% 80% 60% 40% 0% 20%

9 Results *tgenesis = t(ike = 3IKE0)

10 RH and Vt averaged for 1-12 hrs after initialization RHabovePBL = 0% RHabovePBL = 60% RHabovePBL = 100% Vt

11 12-hr period when genesis occurs RHabovePBL = 0% RHabovePBL = 60% RHabovePBL = 100% tgenesis = hrs tgenesis = 81.3 hrs tgenesis = 25.7 hrs *tgenesis = t(ike = 3IKE0)

12 12-hr period when all storms have reached quasi-steady state RHabovePBL = 0% RHabovePBL = 60% RHabovePBL = 100%

13 Methods Approach Idealized 2-D simulations with different initial moisture environments Calculation of efficiencies and budgets Comparison with 3-D re altime forecasts Experimental design Axisymmetric Simplified Pseudoadiabatic Entropy Conserving Hurricane (ASPECH) model Advanced Research Weather Research and Forecasting (ARW) model

14 Conversion of APE efficiency Radiation EAPEtoKE = Conv. of APE to KE Generation of APE Diffusion of heat and water vapor KE APE Surface fluxes Dissipative heating Paulius (2007)

15 Conversion of APE efficiency EAPEtoKE = Conv. of APE to KE Generation of APE Diffusion of heat and water vapor KE APE 1-EAPEtoKE moistening Surface fluxes Dissipative heating

16 Conversion of APE efficiency EAPEtoKE = Conv. of APE to KE Generation of APE 1-EAPEtoKE moistening

17 Mean Conversion of APE Efficiency EAPEtoKE = spinning-up

18 Mean Conversion of APE Efficiency 1-EAPEtoKE moistening

19 Methods Approach Idealized 2-D simulations with different initial moisture environments Calculation of efficiencies and budgets Comparison with 3-D realtime forecasts Experimental design Axisymmetric Simplified Pseudoadiabatic Entropy Conserving Hurricane (ASPECH) model Advanced Research Weather Research and Forecasting (ARW) model

20 Comparison with 3D forecasts

21 Comparison with 3D forecasts

22 Comparison with 3D forecasts Convective features and rainbands

23 Comparison with 3D forecasts

24 Concluding Remarks Question

25 Concluding Remarks Question Seeking for an answer Sensitivity to initial tropospheric RH When downdraft activity stops, RI occurs

26 Concluding Remarks Question Seeking for an answer Quantifying our answer Sensitivity to initial tropospheric RH Precip. efficiency increases with time When downdraft activity stops, RI occurs APE is used to moisten the troposphere

27 Concluding Remarks Question Seeking for an answer Quantifying our answer Comparing to real cases Sensitivity to initial tropospheric RH APE is used to moisten the troposphere Different timescales Hypothesis: convective features in the outer region

28 Acknowledgements Science mentors: Drs. Brian Tang and Shuyi Chen SOARS Team U. of Miami / RSMAS NOAA EPP Travel Award

29 Questions??? NOAA P3 Ocean Heat content mission on TC Bonnie (7/25/2010)

30 Concluding remarks Sensitivity to the initial tropospheric relative humidity Moistening of the inner core up to the upper troposphere Downdraft activity prevents systems from spinning-up Efficiencies Precip. efficiency increases with time APE is used to moist the troposphere and then spin-up the winds Comparison between 2D and 3D Convective features and rainbands in the outer region