Ellen Gray

GPM flying over Earth with a data swath visualized.
Summary will be updated on Fridays through the remainder of the campaign. Latest Update: 2/29/12 Date: February 25 Time: 1600 UTC Event Type: Lake Effect Aircraft: DC-8 Summary: The DC-8 flew home to Dryden Research Flight Center (DRFC) along some points that intersected with light orographic snows in New England and Lake Effect Snows in New York State. The DC-8 intersected snow over the White Mountains near Berlin and Green Mountains south of Rutland before vectoring near Utica, NY, crossing a Lake Effect Snow band southeast of Syracuse, and then traversing just north of a band across the...
NASA's D3R radar at the GCPEx field campaign.
By Ellen Gray, NASA Goddard Space Flight Center Original www.nasa.gov Feature (published 1/31/12) Predicting the future is always a tricky business -- just watch a TV weather report. Weather forecasts have come a long way, but almost every season there's a snowstorm that seems to come out of nowhere, or one that's forecast as 'the big one' that turns out to be a total bust. In the last ten years, scientists have shown that it is possible to detect falling snow and measure surface snowpack information from the vantage point of space. But there remains much that is unknown about the fluffy white...

Snowflakes!

This image of falling snowflakes was taken by the Snow Video Imager (SVI) at one of the auxiliary ground sites, the Steamshow Fairgrounds, 5 miles (8km) south of the main CARE site, during a light snowfall on Saturday, January 21. The SVI is set up about two feet off the ground and the snowflakes are falling from top to bottom through the frame. They can be seen here in different three-dimensional orientations at 5x magnification. In the top left corner and the center right, you can see two examples of classic six-sided dendrite snowflakes. The other flakes with crystals growing up and down
GPM's Snow Ground Validation Underway JacobAdmin Mon, 01/23/2012
The GPM Cold-season Precipitation Experiment (GCPEx) to measure falling snow is currently underway in Ontario, Canada. The field campaign, which runs from January 17 to February 29, 2012, is designed to improve satellite estimates of falling snow and test ground validation capabilities for GPM. Learn more about GCPEx: Airborne Campaign to Measure Falling Snow (press release) GCPEx Overview GCPEx Campaign Blog Ground Validation Image Gallery GPM on Twitter GPM on Facebook

Laying the Groundwork - First Photos from the Field!

GPM's ground validation scientist, Walt Petersen sent us our first photos from the CARE site in Ontario, Canada. Snow's already on the ground, now we're just waiting for more to fall! The University of Bonn ADMIRARI Radiometer deployed at the CARE site. It measures microwaves that are naturally emitted from Earth's surface to determine water vapor and cloud and liquid water in the air column. Credit: NASA / Walt Petersen The NASA D3R radar deployed at the CARE site. This radar scans the air column for snow falling from the clouds to the ground. It uses two frequencies that together can

Day 1: GCPEx Commences

Today the GPM Cold-weather Precipitation Experiment (GCPEx) officially began, and instead of snow, all that came down from the sky was cold rain. Location of the GCPEx experiment Fortunately Environment Canada's Weather Office says significant snow (and, yes, freezing rain, too) is on the horizon for Southern Ontario, where ground stations instrumented to within an inch of their lives are situated. The main GCPEx ground station is at the Centre for Atmospheric Research Experiments (CARE) in Egbert, Ontario, about 44 miles (70 km) north of Toronto and about 27 miles (44 km) southeast of Lake
GCPEx logo on falling snow background
By Ellen Gray, NASA Goddard Space Flight Center Original www.nasa.gov Press Release (published 1/12/12) Beginning Jan. 17, NASA will fly an airborne science laboratory above Canadian snowstorms to tackle a difficult challenge facing the upcoming Global Precipitation Measurement (GPM) satellite mission -- measuring snowfall from space. GPM is an international satellite mission that will set a new standard for precipitation measurements from space, providing next-generation observations of worldwide rain and snow every three hours. It is also the first mission designed to detect falling snow...

Scientists Gather in Denver for the 2011 PMM Science Team Meeting

Over 150 scientists from 10 different countries are meeting in Denver, Colorado, to discuss rain and snow and how to measure them from space. Only once a year members of the Precipitation Measurement Missions (PMM) Science Team come together to discuss the science surrounding both the current Tropical Rainfall Measuring Mission (TRMM) and the upcoming Global Precipitation Measurement (GPM) mission that will launch in 2014. The four-day meeting opened on Monday, November 7th with a focus on the mission status for both TRMM and GPM, and continues with breakout sessions, scientific presentations
GPM flying over Earth with a data swath visualized.
NASA technicians spun the GPM satellite up to just over 10 RPM in Goddard Space Flight Center’s High-Capacity Centrifuge facility March 31 2011. Put Some Spin On It If you've ever taken a fast curve in a car, you've felt your body pushed outward, away from the curve. That outward push is centrifugal force, and the faster you turn, the more it pushes you away from the center. Spinning on the centrifuge does the same thing to the satellite -- except the centrifugal forces are a lot bigger -- capable of going up to 30 times the force of gravity, or "g's." GPM's test went up to seven g's. But...
GPM on the High Capacity Centrifuge
In the clean room at NASA Goddard Space Flight Center in Greenbelt Md., the Global Precipitation Measurement (GPM) mission's Core satellite is steadily taking shape. Set to measure rainfall worldwide after launch in 2014, GPM's two solar panels are the latest components currently undergoing rigorous testing before being integrated with the spacecraft, a process that began seven months ago when the main structural elements went on an unusual ride. GPM moves from the clean room to the test chamber on a dolly without wheels. Compressed air is pumped out under airpads that float the Spacecraft on...