GRIP Lightning Instrument Package (LIP)

Table of Contents

Introduction

The Lightning Instrument Package (LIP) collection contains aircraft observations, which provide detailed "snapshots" of electric fields and total lightning in and around storms that were flown. The collected data is also used to help calibrate surface networks. During the GRIP campaign the LIP instrument package flew aboard the Global Hawk aircraft and consisted of six electric field mills placed at various locations on the aircraft.

The Genesis and Rapid Intensification Processes (GRIP) experiment was a NASA Earth science field experiment conducted August 5 to September 30, 2010. The major goal was to better understand how tropical storms form and develop into major hurricanes. NASA used the DC-8 aircraft, the WB-57 aircraft and the Global Hawk Unmanned Airborne System (UAS), configured with a suite of in situ and remote sensing instruments that were used to observe and characterize the lifecycle of hurricanes. This campaign also capitalized on a number of ground networks and space-based assets, in addition to the instruments deployed on aircraft from Ft. Lauderdale, Florida ( DC-8), Houston, Texas (WB-57), and NASA Dryden Flight Research Center, California (Global Hawk). More information about this Campaign can be found on the GRIP web site: http://grip.nsstc.nasa.gov/

The GRIP Lightning Instrument Package (LIP) consists of 6 rotating vane type electric field sensors along with a central computer to record and monitor the instruments. The field mills measure the components of the electric field over a wide dynamic range extending from fair weather electric fields, (i.e., a few to tens of V/m) to larger thunderstorm fields (i.e., tens of kV/m).

Field Mills

The field mills also provide a measurement of the electric charge (Q) on the aircraft. Total lightning (i.e., cloud-to-ground, intracloud) is identified from the abrupt electric field changes in the data. Often it is possible to differentiate between intracloud and cloud-to-ground discharges. Each field mill incorporates self-calibration capabilities that reduce the time required to obtain a full aircraft calibration. In addition, the electric field signals are digitized at each mill and transmitted as a digital data stream, reducing signal noise and simplifying aircraft integration. To learn more about field mill design, and how they work, visit this web site: http://www.missioninstruments.com/pages/learning/about_fm.html

File Naming Convention

The data files are of the form:

grip_lip_yyyymmdd.asc

where

yyyymmdd = year, month and day
lip = Lightning Instrument Package
asc = ASCII text file

These data are in ASCII format, and there are 12 columns of data in the file. A sample of the data columns is shown below.

The column fields from left to right are as follows:

date (day, month, year)
time (hour, minute, second, milliseconds)
Ex, Ey, Ez and Eq (in V/m)
roll, pitch, heading, latitude and longitude (in degrees)
altitude (in meters above mean sea level)

The data provider is:

Richard Blakeslee
Global Hydrology and Climate Center
320 Sparkman Dr.
Huntsville, Al. 35805
richard.blakeslee@msfc.nasa.gov

To order these data or for further information, please contact:

Global Hydrology Resource Center
User Services
320 Sparkman Drive
Huntsville, AL 35805
Phone: 256-961-7932
E-mail: support-ghrc@earthdata.nasa.gov
Web: http://ghrc.nsstc.nasa.gov/