PRESENTATION BY

ASHNEEL CHANDRA

ENVIRONMENT, SUSTAINABLE DEVELOPMENT AND CLIMATE CHANGE

SCHOOL OF ENGINEERING AND PHYSICS

INTRODUCTION

Cyclones are a common natural disaster in our Pacific islands and causes loss of lives and costs the government millions of dollars to aid in recovery

Many methods have been developed using satellite data and imagery to track cyclones, however, accurate prediction of TC intensity is still needed

Radio atmospherics more commonly known as ‘sferics’ are the electromagnetic radiation occurring in the Extremely Low Frequency (ELF: < 3kHz) and Very Low Frequency (VLF: 3 – 30 kHz) released by lightning activity

For ELF-VLF radio waves, the earth and lower ionosphere act as a waveguide (EIWG) allowing these radio waves to propagate by multiple reflections

The World Wide Lightning Locations Network (WWLLN) was setup with collaboration from various research institutions across the globe to detect strong lightings all over the world

Broad Question

Tropical cyclone morphology and methods of tracking and intensification

Specific Question

Tropical cyclone morphology in the South Pacific region and tracking using VLF radio waves

• (Price et al., 2009) have shown that lightning frequencies in storms could account of about 67% of daily variability in maximum sustained wind speeds and hence predict storm intensification.

• (Abarca et al., 2010) found after studying 24 Atlantic based tropical cyclones that lightning density in the inner core could be of potential use to distinguish between intensifying and non-intensifying storms.

• (Mendoza and Pazos, 2009) have been able to link TC activity to the 22 year solar cycle.

• Geomagnetic activity has been observed to influence cyclonic storms over the North India Ocean (Selvaraj and Uma).

• While sea surface temperature (SST) plays a role in the genesis of TCs, the ocean heat content contained between the sea surface and the depth of the 26°C isotherm, also referred as Tropical Cyclone Heat Potential (TCHP), has been shown to play a more important role in TC intensity changes (Shay et al., 2000).

OBJECTIVES

• Analyze lightning activity in the South Pacific Region for the cyclone and non-cyclone seasons.

• Quantify the variation in lightning activity along cyclone tracks during stages of cyclone development.

• Investigate any correlation between the occurrence of cyclones with solar and geomagnetic activities.

• Examine upper-ocean water properties during cyclonic storms using sea surface temperature and wind speed parameters.

METHODOLOGY

Non-Experimental design strategy with the ex post facto sub strategy will be used

Variables

• Lightning frequencies

• Geomagnetic activity as measured by 𝑘𝑝 index

• Hurricane intensity (The Saffir-Simpson Hurricane Wind Scale)

• Sea surface temperature

• Wind speeds (1 min averaged)

South Pacific region is defined as the region bounded between 0 - 40°S latitudes and 135°E - 120°W longitudes for the purpose of this study.

TCs forming in this region or passing this region at some point in their lifetime will be considered

No ethical issues arise during this research

DATA ANALYSIS

• Lightning data available for the past two years available from the WWLLN Lab at SEP will be analyzed to find variations during cyclone and no cyclone seasons

• Lightning frequencies during TCs occurring in the South Pacific region over the past 10 years will be observed and quantified during the evolution of the TC. Hourly data for TCs will be obtained using the cubic spline method with the use of MATLAB software.

• Geomagnetic activity data for the past 40 years will be analyzed and compared with TC intensification over the years to see if there is any correlation. TC intensification rates will be calculated for the cyclones occurring over the 40 year period along with 𝑘𝑝 index during these

years and correlational analysis done with the help of IBM SPSS software and MATLAB

• Sea surface temperature (SST) data along with literature values of relevant constants will be used to determine energy extracted by TCs from the ocean to see if there is any correlation between TC intensity and energy extracted. SST will be obtained along cyclone tracks. TC intensity as well as energy extraction estimates will be made with the use of physical formulae of inner-core enthalpy flux mentioned in literature.

WORK PLANTASK TO BE PERFORMED DATES PERSONNEL ASSIGNED TO TASK NO. OF DAYS REQUIRED

Obtaining background informationand theory and carrying out literature review on the objectives.

21 July – 31 October 2014 Researcher 102

Obtaining, storing, sorting data.

1 August – 30 November 2014

Researcher 122

Analysing TC and lightning data

1 November – 31 December 2014

Researcher 61

Examining and analysing geomagnetic activity data for past 40 years

1 January – 31 January 2015

Researcher 31

Analysing upper-oceandata pre-, during and after cyclonic storms.

1 February – 31 March 2015

Researcher 59

Thesis write-up 1 March – 31 May 2015 Researcher 92

Corrections and improvements suggested by supervisor

1 June – 28 June 2015 ResearcherSupervisor Co-Supervisor

28

Thesis submission 29 June – 30 June 2015 Researcher 2

BUDGET

CATEGORY UNIT COST MULTIPLYING FACTORS COSTS

1. EQUIPMENT

PC $2,000 (est.) 1 $2,000

External hard disk $200 (est.) 2 $400

1. SUPPLIES

Printing and photocopying

$200 1 $200

Thesis printing, copying and binding

$300 1 $300

Interlibrary loan $600 1 $600

TOTAL $3,500

PLAN FOR PROJECT MANAGEMENT

This project will be managed by the principle investigator with the guidance and advice of the supervisor and co-supervisor

Work schedule will be followed closely for timely completion of this research

CONCLUSION

After this research is complete, it is hoped that the findings will be of great benefit to the weather and forecasting sector

Enable us to understand TC intensification using VLF radio waves generated during lightning

Help us identify and understand long term trends in TC intensification due to solar and geomagnetic activity in the South Pacific region

REFERENCES

• DOWDEN, R., HOLZWORTH, R., RODGER, C., LICHTENBERGER, J., THOMSON, N., JACOBSON, A., LAY, E., BRUNDELL, J., LYONS, T. & KEEFE, S. 2008. World-wide lightning location using VLF propagation in the Earth-ionosphere waveguide. Antennas and Propagation Magazine, IEEE, 50, 40-60.

• EMANUEL, K. 2003. TROPICAL CYCLONES. Annual Review of Earth and Planetary Sciences, 31, 75-104.

• MENDOZA, B. & PAZOS, M. 2009. A 22 yr hurricane cycle and its relation with geomagnetic activity. Journal of Atmospheric and Solar-Terrestrial Physics, 71, 2047-2054.

• PRICE, C., ASFUR, M. & YAIR, Y. 2009. Maximum hurricane intensity preceded by increase in lightning frequency. Nature Geosci, 2, 329-332.

• SELVARAJ, R. S. & UMA, R. Geomagnetic disturbances and Cyclonic Activity over the North Indian Ocean during 22nd Solar Cycle. J. Ind. Geophys. Union (April 2011), 15, 95-100.

• TERRY, J. P. 2007. Tropical cyclones: climatology and impacts in the South Pacific, Springer.

• ZHANG, W., ZHANG, Y., ZHENG, D. & ZHOU, X. 2012. Lightning Distribution and Eyewall Outbreaks in Tropical Cyclones during Landfall. Monthly Weather Review, 140, 3573-3586.