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image of the eye of Hurricane Earl
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GRIP

Genesis and Rapid Intensification Processes

The Genesis and Rapid Intensification Processes (GRIP) field experiment was conducted 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 used to observe and characterize the lifecycle of hurricanes.

The GRIP deployment had bases in Ft. Lauderdale, Florida, for the DC-8; at Houston, Texas, for the WB-57; and at NASA Dryden Flight Research Facility, California, for the Global Hawk. This campaign capitalized on a number of ground networks, airborne science platforms (both manned and unmanned), and space-based assets. 

The field campaign was executed according to a prioritized set of scientific objectives. In two separate science solicitations, NASA selected a team of investigators to collect NASA satellite and aircraft field campaign data with the goal of conducting basic research on problems related to the formation and intensification of hurricanes.

The spaceborne and airborne observational capabilities of NASA put it in a unique position to assist the hurricane research community in addressing shortcomings in the current state of the science. The relatively recent launch of several new satellites, the prospect of using a high-altitude UAS for hurricane surveillance, and the emergence of new remote sensing technologies offered new research tools that needed to be explored and validated. Of great importance were new remote sensing instruments for wind and temperature that can lead to improved characterization of storm structure and environment.

Study DatesAugust 15 - September 30, 2010
RegionTropical Atlantic, Gulf of Mexico, Eastern North Pacific, Caribbean Sea
Season of StudyBoreal fall, boreal summer
Focus AreaHurricanes

DC-8 Instruments

Instrument NameAcronymInvestigatorsTypeProduct Description
Airborne Second Generation Precipitation RadarAPR-2

PI:
Steve Durden, JPL

Co-I:
Simone Tanelli,
Ziad Haddad,
JPL

13/35-GHz dual-frequency Doppler radar

Direct: Lag-0 and lag-1 raw data at 13 and 35 GHz, co- and cross-pol. 

Derived:
HH (co-pol) radar reflectivity at 13 and 35 GHz
Linear Depolarization Ratio (LDR) at 13 and 35 GHz
Vertical Doppler velocity profiles at 13 and 35 GHz

For selected cases:
• Vertical air motion
• Rainfall rate
• Drop-size distribution mean size (or equivalent)

Cloud Aerosol and Precipitation Spectrometer  CAPS

PI:
Andrew Heymsfield, NCAR

Aaron Bansemer, NCAR

Spectrometer + Imaging ProbeDirect: aerosol particle properties, particle size distribution
Cloud Spectrometer and ImpactorCSIImpactorDirect: total cloud liquid water/ice
Precipitation and Imaging ProbePIPImaging Probe

Direct: particle size distribution

Derived products of CAPS-CSI-PIP:
Extinction, effective radius, mean/median cloud particle diameter, ice/liquid water content, radar reflectivity

Doppler Aerosol WiNd lidarDAWN

PI:
Michael J. Kavaya,
NASA LaRC

CO-I:
Robert M. Atlas, NOAA Atlantic Oceanographic and Meteorological Laboratory (AOML)

Jeffrey Y. Beyon,
Grady J. Koch,
Upendra N. Singh,
Bo C. Trieu,
Jirong Yu,
NASA  LaRC

G.David Emmitt, Simpson Weather Associates

Doppler Lidar

Direct: Backscattered light frequency vs. time/range 

Derived:
Vertical profiles of u, v, and w components of 3-D wind in the region below the aircraft.  Various vertical and horizontal resolutions are possible.

Vertical profiles of LOS wind for the five (5) azimuth angles.

Vertical profiles of relative aerosol backscatter (at 2-microns wavelength and circularly polarized light and 30-deg nadir angle), in the region below the aircraft, for the five (5) azimuth angles.

Vertical profiles of wind turbulence in the region below the aircraft, for the five (5) azimuth angles.

Correlations of the data products vs. height.

DC-8 DropsondeDropsondePI:
Jeff Halverson,
NASA GSFC
RadiosondeDirect:
Vertical profiles of pressure, temperature, humidilty, and wind
Langley Aerosol Research Group ExperimentLARGE

PI:
Bruce Anderson,
Gao Chen,
NASA LaRC

Co-I:
Jack Dibb,
University of New Hampshire

Thanos Nenes,
Georgia Tech

Jason Dunion,
Robert Black,
NOAA HRD

In situ aerosol sensors including condensation nuclei counters, optical particle spectrometers, an aerodynamic particle sizer, multi-wavelength particle-soot absorption photometers, and integrating nephelometers

Direct:
Condensation Nuclei
Aerosol Particle Size
Cloud Condensation Nuclei Spectra
Scattering Humidity  
Dependence
Absorption at 405, 532, and 781 nm
Scattering at 450, 550, and 700 nm
Black Carbon Mass, Size
Soluble Ion Composition

Derived:
In Flight (to DC-8 data system)
*Scattering coefficient
* Particle number density
* Displays of size distributions and other parameters

Field Archive (<24 hrs):
* Optical Properties: scattering, absorption, SSA, Angstrom exponents, etc.
* Particle number densities, surface areas, and volumes over 5 discreet size ranges
* CCN at single saturation

Lidar Atmospheric Sensing ExperimentLASE

PI:
Syed Ismail, NASA LaRC

Co-I:
Richard Ferrare, Johnathan Hair
NASA LaRC

Lidar

Direct: Water vapor mixing ratio, aerosol scattering ratio, and cloud distributions.

Derived:
Relative humidity, precipitable water vapor profiles, aerosol backscatter, aerosol extinction, and aerosol optical thickness profiles (815 nm).

Meteorological Measurement SystemMMS

PI:
Paul Bui
NASA ARC

CO-I:
Cecilia Chang & Jonathan Dean-Day,
Bay Area Environment Research Institute (BAERI)

In situ sampling

Direct:
DGPS Positions;
Velocities;
Accelerations;
Pitch, Roll;
Heading;
Angle-of-Attack;
Angle-of-Sideslip;
Dynamic Total Pressures;
Total Temperatures

Derived:
Static pressure;
Static temperature;
Three-dimensional wind vector;
Potential Temperature;
True-Air-Speed;
Turbulence

Global Hawk Instruments

Instrument NameAcronymInvestigatorsTypeProduct Description
Global Hawk DropsondeDropsonde

PI:
Gary Wick,
NOAA ESRL

CO-I:
Michael Black,
NOAA HRD

Dropsonde

Direct:
Wind, temperature, pressure and relative humidity

Derived:
Vertical wind (from dropsonde fall speed), dropsonde location (directly from GPS or from integrating the winds using the aircraft location.

JPL High Altitude MMIC Sounding RadiometerHAMSR

PI:
Bjorn Lambrigtsen,
JPL

Co-I:
Shannon Brown, JPL

Microwave Radiometer

Direct: Brightness temperatures

Derived: Vertical profiles of temperature, water vapor, liquid water

High-Altitude Imaging Wind and Rain Airborne ProfilerHIWRAP

PI: 
Gerald Heymsfield, NASA

CO-I:
Liua Li,
GSFC

James Carswell, Remote Sensing Systems (RSS)

Doppler Radar

Direct:
Reflectivity
Doppler
Surface wind speed, direction
Horizontal. wind speed/direction in precip/cloud regions
Vertical Wind
Precipitation Rate

Derived:
Reflectivity CAPPI’s
Nadir vector wind profile
Wind vectors on CAPPI’s
Ocean surface winds

Lightning Instrument PackageLIP

PI: 
Rich Blakeslee,
NASA MSFC

Co-I:
Monte Bateman,
Universities Space Research Association

Doug Mach,
UAHuntsville

Electric field mills, Conductivity Probe

Direct: Lightning, electric fields, air conductivity

Derived: Electric current (especial storm electric current) derived by combining electric fields and conductivity measurements.

WB-57 Instruments

Instrument NameAcronymInvestigatorsTypeProduct Description
Hurricane Imaging RadiometerHIRAD

PI:
Timothy Miller, NASA/MSFC

Co-I:
Eric Uhlhorn, NOAA HRD

Chris Ruf, University of Michigan

Linwood Jones, University of Central Florida (UCF)

Mark James, NASA/MSFC
(Lead Engineer)

Radiometer

Direct: Brightness temperature at 4, 5, 6, and 6.6 GHz

Derived:
Ocean surface wind speed, and rain rate