GPM Ground Validation Pluvio Precipitation Gauge Field Campaign: LPVEx

Table of Contents

Introduction

The Pluvio Precipitation gauge does continuous, automatic measurement of liquid and solid precipitation using a high resolution electronic weighing system. This dataset contains both one minute measurement and a cumulative record of the accumulation and intensity for liquid, solid, and mixed precipitation. The new generation Pluvio was designed by OTT Hydromet in Kempten, Germany. Pluvio data is gathered from multiple field experiments as part of the Global Precipitaton Measurement (GPM) mission Ground Validatation campaign..

Campaign

The Global Precipitation Measurement (GPM) mission Ground Validation (GV) campaign will use a variety of methods for validation of GPM satellite constellation measurements prior to launch of the GPM Core Satellite, which is currently scheduled for July 2013. The validation effort will entail numerous GPM-specific and joint-agency/international external field campaigns, using state of the art cloud and precipitation observational infrastructure (polarimetric radars, profilers, rain gauges, disdrometers). Surface rainfall will be measured by very dense rain gauge and disdrometer networks at various field campaign sites. These field campaigns will account for the majority of the effort and resources expended by Global Precipitation Measurement (GPM) mission Ground Validation (GV).

LPVEx

The Light Precipitation Evaluation Experiment (LPVEx) took place in September and October 2010 in the Gulf of Finland to characterize the ability of CloudSat, the Global Precipitation Mission (GPM) Dual-frequency Precipitation Radar (DPR), and existing/planned passive microwave (PMW) sensors such as the GPM microwave imager (GMI) to detect light rain and evaluate their estimates of rainfall intensity in high latitude, shallow freezing level environments. The experiment leveraged in situ microphysical property measurements, coordinated remote sensing observations, and cloud resolving model simulations of high latitude precipitation systems to conduct a comprehensive evaluation of precipitation algorithms for current and future satellite platforms. The campaign will use these measurements to better understand the process of light rainfall formation at high latitudes and augment the currently limited database of light rainfall microphysical properties that form the critical assumptions at the root of satellite retrieval algorithm.The Pluvio data files provide 1 minute measurements, total rainfall for a continuous period of precipitation, and toatl liquid water equivalent measured from snowfall observations. More detailed information on the datda format and data levels of the pluvio and related instruments s can be found here.

The Pluvio instruments were located at 3 sites in Finland: Harmaja, Emasalo, and Jarvenpaa. The coordinates of these sites are:

Harmaja:     Lat: 60 degrees 06' 16.02" N ; Lon: 24 degrees 58' 28.80" E
Emasalo:     Lat: 60 degrees 12' 13.38"N ; Lon: 25 degrees 37' 28.49" E
Jarvenpaa:   Lat: 60 degrees 29' 05.05" N; Lon: 24 degrees 04' 56.14" E

Instrument Description

The Pluvio Precipitation Gauge is a high resolution electronic weighing system, which does continuous, automatic measurement of liquid and solid precipitation. The weight of precipitation in the collecting container is measured by an electronic weighting load cell, using the balance principle. Liquid or solid precipitation is measured immediately with no time delay for melting of solid precipitation. The new OTT Pluvio² reliably and accurately measures both the amount and the intensity of liquid, solid, and mixed precipitation. There are filter algorithms to compensate for influences of wind, temperature,and evaporation. This instrument has a very robust design which resists adverse environmental conditions and protects the load cell from impacts

File Naming Convention

Data are available in 3 types of files: 1 minute measurements from Pluvio, raintable and snowtable. The one-minute data are raw measurement files and are level 1A ; the raintable and snowtable files are level 3. The naming conventions respecitively are

pluvio_<site>_yyyymmdd_1min.txt.
pluvio_<site>_raintable.txt       
pluvio_<site>_snowtable.txt  

where,

pluvio =  Pluvio precipitation gauge
site =   Represents the location of the instrument (sites are listed under each campaign)
yyyymmdd = is the year, month and day of the data
1min = 1 minute measurement from the Pluvio.
txt =   ASCII formatted files.

Data Format

These data are in ASCII format. Raintable and snowtable data are available.

Raintable filecontain the total amount of rainfall measured for a continuous period of precipitation, and the snowfalltable files measure the toatl liquid water equivalent from snowfall observatons.

Format of each line:

column 1 - year
column 2 - day of year
column 3 - beginning of precipitation (HH:MM)
column 4 - day of year
column 5 - ending of precipitation (HH:MM)
column 6 - number of precipitation ofr snowvfall observations (minutes)
column 7 - rainfall accumulation (mm), or total liquid water equivalent snowfall (mm)

Example:

 2010  258   13:55  258   18:15   44    7.78
 2010  258   20:00  258   20:20    5    0.93
 2010  259   00:15  259   00:20    2    0.09
 2010  259   03:40  259   03:45    2    0.06

 2010  293   00:43  294   07:41  381   10.59   
 2010  294   11:20  294   11:20    1    0.05
 2010  295   08:48  295   08:48    1    0.05
 2010  297   08:35  297   11:36   39    1.10

Additional information about the Pluvio precipitation gauge can be found in the following PI supplied document:

Data Format - Pluvio2

Contact Information

The data producers are:

Walter A.Petersen
NASA Marshall Space Flight Center
Huntsville, Alabama, 35805

Larry Carey
Earth Systems Science Center
UAHuntsville
Huntsville, AL 35805

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: ghrc@eos.nasa.gov
Web: http://ghrc.nsstc.nasa.gov/