iSWGR

NASA (international) Snow Working Group for Remote Sensing

 Snow from Air & Space:Building a Vision

Mission: To engage U.S. and international science communities in building a vision for future snow remote sensing efforts, including but not limited to, future NASA missions, to promote international collaboration, and engage in capacity-building within the U.S. and international snow remote sensing communities.

iSWGR History

• Visible mapping of snow covered area (SCA) starts w/TIROS satellites in 1962.

• Continues using ESSA, NOAA, GOES and today MODIS and Landsat satellites.

• Combined these have produced a climate data record that is key evidence for climate change.

NOAA visible climate data record

1973 1998 2007

Nov 1966

Oct 1972

May 1975 1980-81 1990s

May 1999

Feb 1997 Feb 2004

ESSA, NOAA, GOESSeries

Weekly 190 kmdigitized

METEOSAT&

GMS added

Reanalysis of 1966-71

IMS 24 km IMS 4 km4

Slide courtesy of Dave Robinson/Rutgers Univ.

iSWGR History cont.

• But SCA is not SWE. This led to two lines of development:• Gamma ray detection of SWE in the mid-west (on-going).• Satellite microwave remote sensing of snow depth and/or snow

water equivalent (SWE) begins in 1970s-80s.

• MW algorithms are simplistic, operational products tend to be limited in accuracy and resolution.

• But these continue to improve with newer regional algorithms and ingestion of ground-based data.

The Satellite Passive Microwave Time Series

Scanning Microwave Multichannel Radiometer (NIMBUS-7)October 1978-August 1987• Relatively narrow swath; shut down every other day

Special Sensor Microwave Imager (DMSP F8, F10, F11, F12, F13, and F15) June 1987-present (F15 - degraded)• Well calibrated inter-sensor

time series

Special Sensor MicrowaveImager/Sounder (DMSP F16, F17, F18)November 2006-present

• Includes sounding frequencies;continuity with DMSP F15

Advanced Microwave ScanningRadiometer (AQUA)June 2002-October 2011

• Improved spatial resolution;addition of 6.9 and 10.7 GHz

Advanced Microwave Scanning Radiometer 2 (GCOM-W)May 2013-present

Sapiano et al, TGARSS, 2013

Passive Microwave Derived Snow Products:‘Standalone’ Snow Water Equivalent

AMSR-E standard product (Kelly, 2008; Tedesco, Kim and others)• Shallow snow detector (89 GHz)• Considers forest fraction• Utilizes 10 GHz for deep snow• Dynamic coefficients for grain size

AMSR-2 standard product (Kelly)

NSIDC (Armstrong and Brodzik, 2002)• Close to the original Chang approach• Correction for vegetation• Static coefficients

NOAA Office of Satellite and Product Operations• Snow depth and SWE available online• Poorly documented

Environment Canada regional products (Goodison; Goita, Derksen and others)• Empirical, static algorithms• Questionable transferability

300

0

iSWGR History cont.

• But gamma tends to be unsuitable for mountain basins, and passive microwave satellite products have resolutions that are too coarse for most hydrologic uses.

• So a group of snow remote sensing scientists begin a series of efforts in 2000 that nearly resulted in a dedicated SWE satellite mission.

• CLPX (2000-2004) SCLP

CLPX: Cold Lands Processes Experiments

SCLP: Snow & Cold Lands Processes Mission

SCLP was a radar + passive microwave mission selected in the 2007 NRC Decadal Survey for Earth Applications from Space. Assigned to Tier 3 category, currently unfunded.

The National Research Council recognizes the need for a U.S. snow mission, but such a mission faces technological hurdles and stiff competition. At the 2012 Chapman Conference on Remote Sensing of the Terrestrial Water Cycle, iSWGR was started and has been working toward realizing that mission and revitalizing U.S. snow research. We need to expand that group to user groups like you. . . .

1952Floods were caused by rapid melt of an above-normal snow cover in eastern Montana, North Dakota, and South Dakota. Record and near record flooding occurred on the Milk River, several tributaries to the Missouri River in North and South Dakota, James River, Big Sioux River, and the Missouri Mainstem.

1993An unusual combination and sequence of hydrometeorological events occurred in the spring and summer of 1993 which culminated in the widespread Midwest flooding known as The Great Flood of 1993. The flooding occurred as a result of a previous wet fall, normal to above-normal snow accumulation, rapid spring snowmelt accompanied by heavy spring rainfall, and heavy rains in June and July.

1995During the spring of 1995, unseasonably warm temperatures in February and March resulted in snow melt which saturated the ground. This, along with repeated heavy rains in the Midwest during March, April, and May, produced significant flooding on many streams and rivers in the Dakotas, Nebraska, Iowa, Kansas, and Missouri, as well as other states.

http://nasasnowremotesensing.gi.alaska.edu/

Comments & Questions?