• Considered in 2009• Startup commitment by JPL in 2010• Partnership with DWR initiated in 2011• Funding committed by NASA in 2012• First snow-free flights Aug 2012 (Tuolumne)• First snow-on acquisition Apr 3 2013 (Tuolumne)• First 24 hour turnaround late April 2013• Expansion of California to include Lakes, Merced, Kings, Rush in 2014• Expansion to include Cherry/Eleanor (2016) and San Joaquin (2017)• 50th full Tuolumne acquisition (2018)• 240 snow-on acquisitions by ASO (2013-2018)

9/17/2018 2

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• ~75% annual precipitation in CA from snow• Seasonal loading of reservoirs

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Water Supply• Less hedging in water supply decisions• Increase wet year allocations for groundwater recharge• Avoid being overly conservative in dry years• Better information for environmental allocations and management• Benefits across dry and wet yearsFlood Management• Defensibility of decisions• Avoided litigation• Avoided property loss• Avoided false alarmsHydropower• Optimization• Value of foreseeable opportunitiesIndirect• Forest Management: fire management, tree mortality, ecosystem

health• Recreation and transportation: trail maintenance, ski area, Caltrans• Landslide and avalanche risk assessment

“What you’ve done there is created essentially new reservoir spacewithout need for environmental impact statements or decades of lawsuits!” – Wes Monier, Turlock Irrigation District

Courtesy of Roger Bales, UCM

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What these measurements give us for April-July (seasonal) runoff forecast errors

Dozier, 2012

1 in 5 years, errors 40%

1 in 2 years, errors 20%

j p l . n a s a . g o vSource: Wes Monier (TID)

“We’ve got to get the water out of there because we have all this snow and we don’t know what’s going to happen,” Glen Pearson said.

South Feather Water and Power water district manager Matt Colwell also talked about balancing the water level and said predicting how much water would come into the reservoir is a stochastic process, which means random variables can affect the reliability of the prediction.

The Mercury News, 24 March 2017

Snow depth• Riegl Q1560 dual

laser scanning lidar• 1064 nm • Full-waveform • 60° field of view

Snow albedo• CASI-1500 Imaging

Spectrometer• 72 bands between

0.35 and 1.05 μm• 40° field of view

• Wall to wall mapping of SWE and albedo

• Weekly flights in winter and spring

• 24 hour turnaround of distributed products and modeling/management distillations

GNSS/IMU – Applanix AP60RTX GNSS correction

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California ASO Program

9/17/2018 14

ASO also operates in the Colorado River Basin, Rio Grande River Basin, and the European Alps

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0

20

40

60

80

ASO: Kings Basin, All except North Fork 04/26/2018

Mea

n S

WE

(in

)

4100

4500

4900

5300

5700

6100

6500

6900

7300

7700

8100

8500

8900

9300

9700

1010

0

1050

0

1090

0

1130

0

1170

0

1210

0

1250

0

1290

0

1330

0

1370

0

1410

0

Elevation (ft)

0

20

40

60

80

ASO: Kings Basin, North Fork 04/26/2018

Mea

n S

WE

(in

)

0

1400

3500

4300

5400

6400

6800

7200

7600

8000

8400

8800

9200

9600

1000

0

1040

0

1080

0

1120

0

1160

0

1200

0

1240

0

Elevation (ft)

April 2, 2015March 30, 2016

Frank Gehrke, CA DWRCalifornia’s Snow Groundhog

March 31, 2017

ASO – Tuolumne River Basin5 year SWE volume

2017Top 5 year

2015Bottom year

Q = SWER2 = 0.9959

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Bulletin 120 RFC Snow-17 and National Water Model

Active effort with DWR, Cooperators, etc.

Active effort with National Water Model team at

National Center for Atmospheric Research

Highway 120, Yosemite National Park

Snow depth (m)

DanaMeadows

Merged point cloud: point density ~1 pt/m2

Ferraz et al, 2018

Ferraz et al, 2018

Merged point cloud: point density ~15 pt/m2

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• CDEC distribution of ASO data is underway

• Just as 100s of scientific papers have been written based on Snow Surveys data out of CDEC distribution, ASO data will anchor new generation of scientific understanding

• Presently 30 universities worldwide are using ASO data for graduate theses 60 and research

• These provide feedback to improved physical and applied understanding

j p l .nasa .gov