ATM 521 Tropical Meteorology FALL 2009 ATM 521

  • Slides: 30
Download presentation
ATM 521 Tropical Meteorology FALL 2009

ATM 521 Tropical Meteorology FALL 2009

ATM 521 Tropical Meteorology Instructor: Room: Phone: E-mail: SPRING 2008 Chris Thorncroft ES 226

ATM 521 Tropical Meteorology Instructor: Room: Phone: E-mail: SPRING 2008 Chris Thorncroft ES 226 518 442 4555 chris@atmos. albany. edu Aim of Course: To describe and understand the nature of tropical weather systems and their role in the tropical climate, including emphasis on the interactions between dynamics and convection. Course Assessment: 1. Homework 2. Class exam on Wednesday 14 th October 3. Final exam on Tuesday 15 th Dec. 8. 00 -10. 00 am Text Books: There is no recommended text book for this course. 15% 30% 55%

ATM 521 Tropical Meteorology SPRING 2008 Lecture Plan: 1. Introduction 2. Tropical Convection (including

ATM 521 Tropical Meteorology SPRING 2008 Lecture Plan: 1. Introduction 2. Tropical Convection (including MCSs) 3. Large-scale Tropical Circulations 4. Kelvin waves 5. Easterly waves 6. Tropical Cyclones Dry spells Flooding: Ghana 07 Flooding: New Orleans 05

1. INTRODUCTION Where are the tropics and what makes them special? Zonal and time

1. INTRODUCTION Where are the tropics and what makes them special? Zonal and time mean circulations Asymmetric circulations

2. TROPICAL CONVECTION Conditional Instability, CAPE, tephigrams Vertical profiles of conserved variables

2. TROPICAL CONVECTION Conditional Instability, CAPE, tephigrams Vertical profiles of conserved variables

MESOSCALE CONVECTIVE SYSTEMS Structure, propagation and longevity issues will be discussed as well as

MESOSCALE CONVECTIVE SYSTEMS Structure, propagation and longevity issues will be discussed as well as their impact on larger scales. See Houze, R. A. , Jr. , 2004: Mesocale convective systems Rev. Geophys. , 42, 10. 1029/2004 RG 000150, 43 pp.

MESOSCALE CONVECTIVE SYSTEMS TRMM based MCS climatology over Africa and tropical Atlantic for June-July-August

MESOSCALE CONVECTIVE SYSTEMS TRMM based MCS climatology over Africa and tropical Atlantic for June-July-August Rainfall Percentage of MCSs with significant ice scattering Stratiform Rain Fraction Average Lightning flash density Schumacher and Houze (2006) QJRMS : Less stratiform rain over sub-Saharan Africa than Atlantic but, Stratiform rain increases in monsoon season compared to pre-monsoon season due to (i) reduced upper-level shear? , (ii) reduced impact of dry SAL? , (iii) other?

3 LARGE-SCALE TROPICAL CIRCULATIONS Key features of the West African Monsoon Climate System during

3 LARGE-SCALE TROPICAL CIRCULATIONS Key features of the West African Monsoon Climate System during Boreal summer Heat Low SAL AEJ ITCZ Observations and theory of monsoons Theories for large-scale motion Emphasis given to West African Monsoon Cold Tongue

4. KELVIN WAVES Easterly waves are the dominant synoptic weather system in the Africa.

4. KELVIN WAVES Easterly waves are the dominant synoptic weather system in the Africa. Atlantic sector but they also exist in other basins (e. g. Pacific) We will discuss their structure and theories for their existence and growth including how they interact with MCSs (see next slides).

5. EASTERLY WAVES Easterly waves are the dominant synoptic weather system in the Africa.

5. EASTERLY WAVES Easterly waves are the dominant synoptic weather system in the Africa. Atlantic sector but they also exist in other basins (e. g. Pacific) We will discuss their structure and theories for their existence and growth including how they interact with MCSs (see next slides).

Diagnostics for highlighting multi-scale aspects of AEWs 315 K Potential Vorticity (Coloured contours every

Diagnostics for highlighting multi-scale aspects of AEWs 315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1

315 K Potential Vorticity (Coloured contours every 0. 1 PVU greater than 0. 1 PVU) with 700 h. Pa trough lines and easterly jet axes from the GFS analysis (1 degree resolution), overlaid on METEOSAT-7 IR imagery.

6. TROPICAL CYCLONES Observations and theory of tropical cyclones including issues that relate to

6. TROPICAL CYCLONES Observations and theory of tropical cyclones including issues that relate to genesis, structure and track

6. TROPICAL CYCLONES Key weather systems in the West African and Tropical Atlantic regions

6. TROPICAL CYCLONES Key weather systems in the West African and Tropical Atlantic regions An ideal region to study scale interactions including how they impact downstream tropical cyclogenesis SAL TC AEWs MCSs

FINAL COMMENTS The course is fundamentally about the interactions between dynamics and convection, combining

FINAL COMMENTS The course is fundamentally about the interactions between dynamics and convection, combining observations, modeling and theory. Ultimately a major motivation for research in this area is to improve our ability to predict tropical convection (over a range of space and timescales). This remains a major challenge and MUCH remains to be learned. The above is a major motivation for the proposed Year Of Tropical Convection (YOTC) a WCRP/THORPEX supported virtual field campaign that will likely begin during 2008. It is also a motivation for a joint AMMA-THORPEX Working Group that exists to evaluate and develop forecasting methods for the West African region. More information about both these activities will be provided during the course.