On the relationship of in-cloud convective turbulence and total lightning Wiebke Deierling, John Williams, Sarah Al-Momar, Bob Sharman, Matthias Steiner and Cathy Kessinger

Our Purpose Examine possible relationships between lightning occurrence and turbulence production for different storm types Examine relationships over CONUS first because of good data coverage Extend examination to oceanic storms in the near future If successful, GLM on GOES-R may provide valuable information for underserved regions to help identify regions of convective turbulence

Background – Updraft and Lightning Reflectivity 5.5 km MSL - Evidence that updraft volume correlates with total lightning (Wiens et al. 2005, Deierling et al. 2008) - Large updraft volumes of higher updraft speeds are capable of producing more hydrometeors in the mixed ice phase region, promoting electrification − − Turbulence − Question: How does convective turbulence relate to total lightning?

Data Sets Used Turbulence intensity: – NEXRAD Turbulence Detection Algorithm (NTDA) Eddy Dissipation Rate (EDR) Radar reflectivity: – NTDA mosaic NTDA Turbulence PID East-West Distance [km] North-South Distance [km] Height [km Time [ms] LMA Detected Lightning In-Cloud and Cloud-to-Ground Lightning: – Measured by Lightning Mapping Array (LMA) at New Mexico and Northern Colorado LMA Flash Extent NTDA Reflectivity NTDA EDR

Growing Air Mass Storms at 21:55UTC EDR – light-moderate- severe color scale EDR LMA 3D lightning Radar Reflectivity  Higher Turbulence and lightning in upper levels of cloud.  Highest turbulence above highest lightning VHF sources above highest radar reflectivity.

Mature Air Mass Storms at 22:20UTC Radar Reflectivity EDR – light-moderate- severe color scale EDR LMA 3D lightning Radar Reflectivity

Decaying Air Mass Storms at 23:20UTC EDR – light-moderate- severe color scale EDR LMA 3D lightning Radar Reflectivity

Horizontal LMA Flash Extent Radar reflectivity volume>35 dBZ for T<0C EDR Volumes for T 0.15 Red: EDR>0.3 (multiplied by 5)

LMA Flash Extent [fl/km 2 ] Variations by Lifecycle Developing storm Mature storm Decaying storm r=0.75 r=0.87 Total Lightning vs. Z>35dBZ volume for T<0C Total Lightning vs. EDR>0.3 volume for T<0C

Horizontal Cross-Section with Height Light Moderate Severe Light Moderate Severe Reflectivity 5.5 km MSL EDR FL 150 EDR FL 330 Extreme EDR values at different height levels and horizontal lightning extent contours (magenta). During growth period of storms, the turbulent regions tend to: Have a larger area of MOD turbulence at higher levels within storms Are horizontally aligned (not necessarily vertically aligned) with lightning regions

5 min Total Lightning EDR Volume of EDR>0.2  Best correlation for total EDR volumes for EDR values >  New Mexico air mass storms, total lightning correlates best to light- moderate turbulence at FL Total Ltg & EDR volume>0.2 of Air Mass Storms in New Mexico over 2 weeks R=0.89

CO Severe Storms – Mature Stage NTDA EDR LMA 3D lightning NTDA Radar Reflectivity  Higher turbulence regions often above highest VHF source densities above highest radar reflectivity

Severe Storms – CO NTDA EDR LMA 3D lightning NTDA Radar Reflectivity  Severe storm cells on 27 May 2013  SPC reports of several tornadoes, 1 inch hail, and 60 knot winds

VHF sources35 dBZ Refl. EDR>0.15 EDR>0.3 EDR>0.4 EDR>0.3 EDR>0.15 Time [UTC] Severe Storms – CO Time –Height histograms Time [UTC]

 Higher lightning frequencies relate to higher turbulence intensities  Most storms exhibited charge centers in between the maximum reflectivity cores and peak turbulence during a storms mature stage  Regions of higher EDR are horizontally collocated with higher flash extents for air mass storms  EDR and lightning relationship looks promising for air mass storms but more complicated for severe storms, needs more investigation  Look at more storm types, including oceanic storms  Compare with modeling studies Summary & Outlook

Thank you!