# Presentation: 405257

## Total Lightning Observations With New and Improved

**Total Lightning Observations With New and Improved**
**Los Alamos Sferic Array (LASA) **
** **
- Xuan-Min Shao,
- Mark Stanley, Jeremiah Harlin, Amy Regan, Morrie Pongratz, Mike Stock
*Space and Remote Sensing Sciences Group, ISR-2*
*Los Alamos National Laboratory*

- Southern Thunder Workshop , Ft. Worth, 07/25-27/05

## Florida LASA

**Florida LASA**
**Eight stations deployed in April, 2004**

- Deployed
- April, 2004

- Operated via
- Internet

- Sensor on
- Roof

## GPS Block IIF: V-GLASS 

**(**_**V**_**HF **_**G**_**lobal **_**L**_**ightning **_**A**_**nd **_**S**_**evere **_**S**_**torm Monitor)**** **

-                         _MISSION_
-       Global VHF Lightning and Total
-     Electron Content (TEC) Monitoring
-       Lightning detection as proxy for
-            monitoring deep convection
-           An extension of an already-
-                scheduled DoD mission
-            using existing h/w and s/w
-                       _PLATFORM_
- Platform:	GPS Constellation
-                        (24 Block IIF/III satellites)
- Altitude: 	20,000 km
- Launches: 	2007-2011
-                         _SENSORS_
- Type:	Broadband VHF receivers
- Capability:  Event time, 3D location, TEC
- Lightning/sec/sat:   ~  1 - 10
- Coverage:	1 gnd stat.  (regional, real-time)
-                  ~ 4 gnd stats. (global, real-time)

- V-Sensor

## Samples of E-Field Changes

**ELVES observed by ISUAL**

- 8 ms

- 1 ms

**Samples of E-Field Changes**

**IC**

**+CG**

**-CG**

**Energetic -CG**

## 	New processing algorithm allows each peak detected and located 

**	****New processing algorithm allows each peak detected and located **
**	****(1) Convert E-field to power, (2)detect power peaks, (3) match peaks among stations, (4) time-tag matched peaks, (5) locate peaks.**

- Hilbert Transform

- Match peaks among stations

## 	Air mass, afternoon storms monotonically produce ~3-4 time more ICs than CGs, and uniformly produce NBs

**	****Air mass, afternoon storms monotonically produce ~3-4 time more ICs than CGs, and uniformly produce NBs**
**	**

## 	Frontal storms associated with variable IC/CG ratios, depending on storm stages, and only selectively produce NBs

**	****Frontal storms associated with variable IC/CG ratios, depending on storm stages, and only selectively produce NBs**

## Radar

**Radar**

**EdotX**

**LASA vs. NEXRAD: able to outline structures of active storm cells. Can be used to now-cast severe storms**

## 2-D location accuracy, < 0.5 km near the dense array

**2-D location accuracy, < 0.5 km near the dense array**

**Located 8 of 13 triggered return strokes at Camp Blanding in 2004**
**Peak currents: 3.6-17.8 kA**
**Location errors: 20-156 m with an average 91 m. **

## Detection efficiency

**Detection efficiency**
**A few kAs within 100km, 25 kA at 600 km. 2-5 more ICs than CGs within 100 km**

## Daily trigger rate: 106 – 107

**Daily trigger rate: 10****6**** – 10****7**

## 3-D capability for lightning near the dense array

**3-D capability for lightning near the dense array**
**Total of 724 in 4 minutes, 120 are return strokes**

## 3-D observation of small cell

**3-D observation of small cell**
**Notice the source height development. 498 pts in 50 min**

## Great Plains Array deployed in April, 2005

**Great Plains Array deployed in April, 2005**
**Algorithms development underway**

## LASA captured a handful lightning events that are tightly associated with TGFs detected by RHESSI satellite. 

**LASA captured a handful lightning events that are tightly associated with TGFs detected by RHESSI satellite. **
**All waveforms are similar but exotic. No NB was found associated with TGF**

## Measured attenuation agrees with simulation: a possible tool for soil conductivity and water content mapping 

**Measured attenuation agrees with simulation: a possible tool for soil conductivity and water content mapping **
**(meters deep into earth, progress underway)**

- Blue: PLK
- Green: GNV
- Red: TPA
- Black: TLH

**Spectrum ratios between inland and DAB stations. **
**More attenuation at farther stations.  **
**Path to TPA more conductive than to GNV?**

- LB cutoff freq

## Summary

** ****New LASA FLN operated continuously since April, 2004**
** ****Captures full waveforms without any trigger dead time**
** ****Detects several to several tens events per flash**
** ****Can readily distinguish ICs, CGs, and NBs**
** ****3-D capability for lightning near the dense array**
** ****Great Plains Array started operation in April, 2005**
** ****Compared to other observations, e.g., TGF, Sprit. **