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        GHRC also hosts a database of Atlantic and Pacific tropical storm tracks derived from the storm data published by the National Hurricane Center (NHC).
    • HS3 (2012-14)
      • Hurricane and Severe Storm Sentinel (HS3) is an Earth Ventures – Suborbital 1 mission aimed at better understanding the physical processes that control hurricane intensity change, addressing questions related to the roles of environmental conditions and internal storm structures to storm intensification.

        A variety of in-situ, satellite observations, airborne data, meteorological analyses, and simulation data were collected with missions over the Atlantic in August and September of three observation years (2012, 2013, 2014). These data are available at GHRC beginning in 2015.
    • GRIP (2010)
      • The Genesis and Rapid Intensification Processes (GRIP) experiment was a NASA Earth science field experiment in 2010 that was conducted to better understand how tropical storms form and develop into major hurricanes.

        The GRIP deployment was 15 August – 30 September 2010 with bases in Ft. Lauderdale, FL for the DC-8, at Houston, TX for the WB-57, and at NASA Dryden Flight Research Facility, CA for the Global Hawk.
    • TC4 (2007)
      • The NASA TC4 (Tropical Composition, Cloud and Climate Coupling) mission investigated the structure and properties of the chemical, dynamic, and physical processes in atmosphere of the tropical Eastern Pacific.

        TC4 was based in San Jose, Costa Rica during July 2007.

        The Real Time Mission Monitor provided simultaneous aircraft status for three aircraft during the TC4 experiment. During TC4, the NASA ER-2, WB-57 and DC-8 aircraft flew missions at various times. The science flights were scheduled between 17 July and 8 August 2007.
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      • The NASA African Monsoon Multidisciplinary Analyses (NAMMA) campaign was a field research investigation based in the Cape Verde Islands, 350 miles off the coast of Senegal in west Africa.

        Commenced in August 2006, NASA scientists employed surface observation networks and aircraft to characterize the evolution and structure of African Easterly Waves (AEWs) and Mesoscale Convective Systems over continental western Africa, and their associated impacts on regional water and energy budgets.
    • TCSP (2005)
      • The Tropical Cloud Systems and Processes (TCSP) mission was an Earth science field research investigation focused on the study of the dynamics and thermodynamics of precipitating cloud systems and tropical cyclones. TCSP was conducted during the period July 1-27, 2005 out of the Juan Santamaria Airfield in San Jose, Costa Rica.

        The TCSP field experiment flew 12 NASA ER-2 science flights, including missions to Hurricanes Dennis and Emily, Tropical Storm Gert and an eastern Pacific mesoscale complex that may possibly have further developed into Tropical Storm Eugene.
    • ACES (2002)
      • The Altus Cumulus Electrification Study (ACES) was aimed at better understanding the causes and effects of electrical storms.

        Based at the Naval Air Station Key West in Florida, researchers in August 2002 chased down thunderstorms using an uninhabited aerial vehicle, or "UAV", allowing them to achieve dual goals of gathering weather data safely and testing new aircraft technology. This marked the first time a UAV was used to conduct lightning research.
    • CAMEX-4 (2001)
      • The Convection And Moisture EXperiment (CAMEX) was a series of NASA-sponsored hurricane science field research investigations. The fourth field campaign in the CAMEX series (CAMEX-4) was held in 16 August - 24 September, 2001 and was based out of Jacksonville Naval Air Station, Florida.

        CAMEX-4 was focused on the study of tropical cyclone (hurricane) development, tracking, intensification, and landfalling impacts using NASA-funded aircraft and surface remote sensing instrumentation.
    • CAMEX-3 (1998)
      • The Convection And Moisture EXperiment (CAMEX) is a series of hurricane science field research investigations sponsored by NASA. The third field campaign in the CAMEX series (CAMEX-3) was based at Patrick Air Force Base, Florida from 6 August - 23 September, 1998.

        CAMEX-3 successfully studied Hurricanes Bonnie, Danielle, Earl and Georges, yielding data on hurricane structure, dynamics, and motion. CAMEX-3 collected data for research in tropical cyclone development, tracking, intensification, and landfalling impacts using NASA-funded aircraft and surface remote sensing instrumentation.
    • GPM Ground Validation
      • The NASA Global Precipitation Measurement Mission (GPM) Ground Validation (GV) program includes the following field campaigns:

        a) LPVEx, Gulf of Finland in autumn 2010, to study rainfall in high latitude environments

        b) MC3E, cental Oklahoma spring and early summer 2011, to develop a complete characterization of convective cloud systems, precipitation and the environment

        c) GCPEx, Ontario, Canada winter of 2011-2012, direct and remove sensing observations, and coordinated model simulations of precipitating snow.

        d) IFloodS, Iowa, spring and early summer 2013, to study the relative roles of rainfall quantities and other factors in flood genesis.

        e) IPHEx, N. Carolina Appalachians/Piedmont region May-June 2014, for hydrologic validation over varied topography.

        f) OLYMPEx, Washington's Olympic Peninsula scheduled November 2015-February 2016, for hydrologic validation in extreme coastal and topographic gradients
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    • IPHEx (2014)
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        IPHEx sought to characterize warm season orographic precipitation regimes, and the relationship between precipitation regimes and hydrologic processes in regions of complex terrain.
    • IFLOODs (2013)
      • The Iowa Flood Studies (IFloodS) experiment was conducted in the central to northeastern part of Iowa in Midwestern United States during the months of April-June, 2013.

        IFloodS' primary goal was to discern the relative roles of rainfall quantities such as rate and accumulation as compared to other factors (e.g. transport of water in the drainage network) in flood genesis.
    • GCPEX (2011-2012)
      • The GPM Cold-season Precipitation Experiment (GCPEx) occurred in Ontario, Canada during the winter season (Jan 15- Feb 26) of 2011-2012.

        GCPEx addressed shortcomings in GPM snowfall retrieval algorithm by collecting microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. Collectively the GCPEx data set provides a high quality, physically-consistent and coherent data set suited to the development and testing of GPM snowfall retrieval algorithm physics.
    • MC3E (2011)
      • The Mid-latitude Continental Convective Clouds Experiment (MC3E) took place in central Oklahoma during the April–June 2011 period.

        The overarching goal was to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that had never before been available.
    • LPVEx (2010)
      • The Light Precipitation Evaluation Experiment (LPVEx) took place in the Gulf of Finland in September and October, 2010 and collected microphysical properties, associated remote sensing observations, and coordinated model simulations of high latitude precipitation systems to drive the evaluation and development of precipitation algorithms for current and future satellite platforms.

        In doing so, LPVEx sought to address the general lack of dedicated ground-validation datasets from the ongoing development of new or improved algorithms for detecting and quantifying high latitude rainfall
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      • DISCOVER was funded by NASA’s MEaSUREs program to provide highly accurate, multi-decadal geophysical products derived from satellite microwave sensors.
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      • The SANDS project addressed Gulf of Mexico Alliance priority issues by generating enhanced imagery from MODIS and Landsat data to identify suspended sediment resulting from tropical cyclones. These tropical cyclones have significantly altered normal coastal processes and characteristics in the Gulf region through sediment disturbance.
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      • The Land, Atmosphere Near real-time Capability for EOS (LANCE) system provides access to near real-time data (less than 3 hours from observation) from AIRS, AMSR2, MLS, MODIS, and OMI instruments. LANCE AMSR2 products are generated by the AMSR Science Investigator-led Processing System at the GHRC.
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DOCUMENTATION

Documentation

Guide Documents

Dataset PI Documents

Dataset Software

CAMEX-4 LIDAR Atmospheric Sensing Experiment (LASE)

Table of Contents

Introduction
Principles of Operation
Data Naming Conventions and Data Format
Contact Information

Introduction

NASA's Lidar Atmospheric Sensing Experiment (LASE) system was operated during the the Fourth Convective and Moisture Experiment (CAMEX-4) to characterize water vapor fields in the vicinity of hurricanes. While remote sensing of the hurricane environment was the primary objective of CAMEX-4, there were also separate flights to study thunderstorm structure, precipitation systems, and atmospheric water vapor profiles. This portion of CAMEX-4 was known as KAMP, Keys Area Microphysics Project. The objective of the KAMP flights was to improve quantitative precipitation estimates from passive and active microwave instruments. LASE was operated during both CAMEX-4 and KAMP.

LASE was operated from the NASA DC-8 aircraft in the nadir and zenith modes simultaneously. Six DC-8 flights were made in the vicinity of hurricanes and four KAMP flights were made into areas of heavy rain convection. In addition, there were two instrument check flights and one calibration flight over the Andros Island site during the CAMEX-4 period between August 18 and September 24, 2001. LASE collected profile data using a combination of three water vapor absorption cross-sections over a period of more than 70 hours.

Data may be obtained from the GHRC (see contact information below), or directly from the CAMEX-4 web page. The LASE homepage is found at http://asd-www.larc.nasa.gov/lidar/cmx4/camex4.html from which additional information may be found.

Principles of Operation

LASE is an airborne DIAL (Differential Absorption Lidar) system used to measure water vapor, aerosols, and clouds throughout the troposphere. This system uses a double-pulsed Ti:sapphire laser, which is pumped by a frequency-doubled flashlamp-pumped Nd:YAG laser, to transmit light in the 815-nm absorption band of water vapor. The Ti:sapphire laser wavelength is controlled by injection seeding with a diode laser that is frequency locked to a water vapor line using an absorption cell. LASE operates by locking to a strong water vapor line and electronically tuning to any spectral position on the absorption line to choose the suitable absorption cross-section for optimum measurements over a range of water vapor concentrations in the atmosphere. During CAMEX-4, LASE operated from the NASA DC-8 using strong and weak water vapor lines in both the nadir and zenith modes, thereby simultaneously acquiring data below and above the aircraft. The strongly absorbing, temperature insensitive water vapor line at 817.2231 nm (12236.5603 cm-1) with a line strength of 4.060E-23 cm, linewidth of 0.0839 cm-1, and lower energy state of 224.838 cm-1 was used during CAMEX-4. Line strength accuracy is estimated to be 2% and linewidths have agreed with other measurement to within 2 0iving an overall accuracy of absorption cross-section of less than 3% (Poinsardin and Browell, 1997). Effective absorption cross-section profiles were calculated at the on-line and off-line wavelengths and the side-line positions, and corrections for Doppler broadening, pressure shift, water vapor line width, spectral purity, molecular density, and aerosol scattering ratio were used in water vapor mixing ratio retrievals (Ismail et al., 1989).

Absolute water vapor distributions will be derived from the LASE measurements across the troposphere from 0-14 km over a mixing ratio range of about 20 g/kg to 0.01 g/kg. The initial archive contains only the nadir water vapor distributions. The LASE nadir water vapor profiles have a vertical resolution of 330 m. For all flights, the LASE nadir water vapor profiles have a temporal averaging period of 3 minutes, which corresponds to a horizontal distance of about 42 km. Other temporal averaging periods can be produced upon request. Previous water vapor comparisons have shown the LASE water vapor mixing ratio measurements have an accuracy of better than 60r 0.01 g/kg, whichever is larger, across the troposphere (Browell et al., 1997).

In addition to measuring water vapor mixing ratio profiles, LASE simultaneously measures aerosol backscattering profiles at the off-line wavelength near 815 nm. Profiles of the aerosol scattering ratio, defined as the ratio of aerosol scattering to molecular scattering, are determined by normalizing the scattering in the region containing enhanced aerosol scattering to the expected scattering by the "clean" (molecular only) atmosphere at that altitude. For these CAMEX-4 measurements, the LASE nadir and zenith aerosol scattering ratio profiles have a vertical resolution of 60 m for all nadir measurements and for zenith measurements in flights 8, 10, 11, and 12 (zenith measurements in all other flights have a resolution of 2 km due to extensive clouds). Both nadir and zenith aerosol scattering ratio profiles have a horizontal resolution of 9 seconds (~2.1 km).

Data Naming Conventions and Data Format

The data files archived at the GHRC are tarred into daily files that have the format:

c4dlase_2001.246_010409.tar

where c4dlase is the dataset identifier, 2001.246 is the year.day-of-year, 010409 is the mission number

When 'untarred', the daily file will extract two data files and numerous image files. Their naming convention is as follows:

bcyyyymmdd.cm4
wcyyyymmdd.cm4
cm4_nnnn.gif

where 'bc' and 'wc' are file type identifiers used in the read software, 'cm4' identifies this as a CAMEX-4 file, yyyy is the four digit year, mm is the two digit month and dd is the two digit day. In the image file, nnnn represents the different types of image files (e.g. asr, h2o, etc).

These are described in greater detail in LASE_CAMEX-4_data_documentation.pdf which is the document prepared by the data producer.

Format specification for Data Exchange by Steve E. Gaines and R. Stephen Hipskind may be found either online at http://cloud1.arc.nasa.gov/solve/archiv/archive.tutorial.html which has been converted to PDF format here. LASE uses format number 2310.

There is a program written to read the Gaines/Hipskind format 2310 for LASE/CAMEX-4 ascii archive files. It is echoed below, or may be found in a file named c4dlase_rd_cm4_2310.pro.

pro rd_cm4_2310,fn,max_pts,rec,ohdr,odata,scale,flag,rm_flags=rm_flags
; Reader for gaines/hipskind format 2310 for LASE/CAMEX-4 ascii archive files.
; 12/3/2000 sk
; modification 7/25/2001 mbc:
; keyword rm_flags - removes interpolation and in situ data flags
; input -- name of archive file
; output
; -- max_pts, size of largest profile
; -- rec, number of profiles in the file
; -- ohdr, fltarr, array of header info
; time, elapsed seconds from start
; number of values in the profile
; gps altitude of first data word, meters
; altitude increment, meters
; gps altitude of aircrage, meters
; time, hrs
; time, min
; time, sec
; gps latitude, degrees N
; gps longitude, degrees E
; -- odata, 2 dim array of data, sized max_pts, rec
; -- scale, array of scale factors for data
; -- flag, array of bad data flags for data
;
; Limitations -- the data matrix is not altitude aligned. This can be done
; with the information in the profile headers. For each profile,
; the third header entry is the altitude of the first data word, the fourth
; header entry is the altitude interval between consecutive data values.
; for example, to calculate the altitude profile for profile 10
; i= 10
; alt_arr= findgen(ohdr(1,i)) * ohdr(3,i) + ohdr(2,i)
; plot,odata(*,i),alt_arr
;

openr,l,fn,error = err,/get
if(err ne 0) then begin
print, -2, !err_string
stop
endif

; read header saving scale and flag values only

aline=''
rd_cnt= 0
readf,l,num_head,num_format
if(num_format ne 2310) then begin
print,' Wrong archive format file = ',num_format
print,' Expected format 2310 only!
return
endif
rd_cnt= rd_cnt+1
for i=1,9 do begin
readf,l,aline
rd_cnt= rd_cnt+1
endfor
readf,l,nvar
rd_cnt= rd_cnt+1
readf,l,scale
rd_cnt= rd_cnt+1
readf,l,flag
rd_cnt= rd_cnt+1
readf,l,aline
rd_cnt= rd_cnt+1
readf,l,nhdr
rd_cnt= rd_cnt+1
h_scale=fltarr(nhdr)
h_flag=lonarr(nhdr)
readf,l,h_scale
h_scale= [1.0,h_scale] ; time (elapsed secs) + header values
rd_cnt= rd_cnt+1
readf,l,h_flag
rd_cnt= rd_cnt+1
while(rd_cnt lt num_head) do begin
readf,l,aline
rd_cnt= rd_cnt+1
endwhile
; read data assuming LASE 11 hrs max at full resolution (6 sec/rec)
max_recs= 11.*60./.1
max_points= 500
hdr=fltarr(nhdr+1,max_recs)
h=fltarr(nhdr+1)
rec=0
data=fltarr(max_points,max_recs)
while not(eof(l)) do begin
readf,l,h
hdr(*,rec)= h * h_scale
x=lonarr(h(1)) ; length of profile varies
readf,l,x
x = x * scale
if (keyword_set(rm_flags)) then undo_flags2,x
data(0:h(1)-1,rec)= x
rec= rec+1
endwhile
rec=rec-1
print,' Done reading ',rec,' records from '+fn
free_lun,l
;
; cleanups
;
max_pts=max(hdr(1,*))
print,' Largest profile has ',max_pts,' values.'
flag= flag*scale
orig_h_flag=h_flag
h_flag= h_flag*h_scale(1:*)
odata=replicate(h_flag(1),max_pts,rec)
for i=0, rec-1 do begin ; resize data to largest profile
odata(0:max_pts-1,i)= data(0:max_pts-1,i)
endfor
ohdr=fltarr(nhdr+1,rec)
for i=0, nhdr do begin
xx= hdr(i,0:rec-1)
ohdr(i,*)= xx
endfor
end

pro undo_flags2,profiles

flag1=where((profiles gt 9000.1) and $
(profiles lt 13000.),count1)
flag2=where((profiles gt 99000.1) and $
(profiles lt 103000.) and $
(profiles ne 99999.9) and $
(profiles ne 99999.0),count2)
flag3=where((profiles gt 999000.1) and $
(profiles lt 1003000.),count3)
flag4=where((profiles gt 990) and $
(profiles lt 1100),count4) ; H2O only!!!!!!!!!
if (count1 gt 0) then profiles(flag1)=profiles(flag1)-10000.
if (count2 gt 0) then profiles(flag2)=profiles(flag2)-100000.
if (count3 gt 0) then profiles(flag3)=profiles(flag3)-1000000.
if (count4 gt 0) then profiles(flag4)=profiles(flag4)-1000.

return
end

Contact Information

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/

 

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