Observing Climate with Satellites:Are We on Thin Ice?

Compton TuckerNASA/Goddard Space Flight Center

Greenbelt, Maryland USA

Why NASA? Why NASA?

NASA uses space for exploration NASA uses space for exploration & scientific discovery& scientific discovery

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Hubble Hubble ImagesImages

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Looking downBahamas

Earth Sensing Requires Using Unique Frequencies

• Atmospheric temperature soundings: 23.8, 31.4, 50.0-58.0, 89.0, 150.0, & 183.0 GHz

• Sea ice detection: 22.0, 19.0, & 37 GHz• Sea level radar altimetry: 5.3, 13.6, 18.0, 21-22,

& 37 GHz• Ocean Salinity: 1.26, 1.413, 23.8, & 36.5 GHz

Summary of Talk

• Observations not beliefs• Satellites & spectrum allocation v. important• Sun constant since late 1970s• Earth is warming• Greenhouse gases/human activities are

responsible, ice sheets are melting...

• Residence time of CO2 is LONG...

Definitions

Without proper definitions, logical discourse is impossible.

Without logical discourse, nothing can be accomplished.

Confucius

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Is the Earth Warming?

• Surface thermometers increasing• Atmospheric temp. increasing• Glaciers• Sea Ice• Ocean temperatures increasing• Sea level rising• Sun no change

melting

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Fundamental discovery that the TSI is ~1361 W m-2, not 1366 W m-2

Total Solar Irradiance Record

TIM

-4.5 W m-2

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Total Solar Irradiance Record

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• In the satellite record, total solar irradiance varied by ~one part in 500one part in 500• T ~ 0.1˚CT ~ 0.1˚C, nearly all associated with the ~11-year solar cyclesolar cycle

Global Warming—Keep it Simple• The Earth warms, sea level rises• The Earth cools, sea level falls

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~60% thermal expansion~60% thermal expansion

~40 glacial melt~40 glacial melt

Tide Gauge Measurements

About +1.5 ft in 150 years

At the maximum

extent of the last ice age,

sea level was over 400 feet

lower.

Florida was about twice its current

size

Last Glacial Maximum Sahulland

When the ice melted, sea level rose

1.7 m/100 yr

Scandinavian Post-Glacial Rebound

Stockholm, Sweden

Sea level can be very accurately measured by satellites

C band (5.3 GHz) & Ku band (13.6 GHz), +18, 21, & 37 GHz for

water vapor correction

rise = 1.5’/150 yr

Gravity Recovery & Gravity Recovery & Climate ExperimentClimate Experiment

500 km orbit500 km orbit

220 km separation220 km separation

Distance accuracy Distance accuracy 0.001 mm0.001 mmFFgg = G( m = G( m11*m*m22)/r)/r22

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Greenland Ice Mass Flux from GRACE mascon solution

Photo Credit: Roger Braithwaite

(update to Luthcke et al. Science (update to Luthcke et al. Science 2006) 2006)

1 Giga-ton = 1 Billion metric tons1 Giga-ton = 1 Billion metric tons

1,200 Giga-ton ~ 1,300 1,200 Giga-ton ~ 1,300 kmkm33 of ice or 310 mi of ice or 310 mi3 3 of of iceice

3.4 mm of global sea 3.4 mm of global sea level rise.level rise.

NASA GSFC mascon solution (update to

Luthcke et al. Science 2006)

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Antarctica & Alaska GRACE

Antarctic Ice Sheet Mass Variation from GRACE

NASA GSFC Global Mascon Solution (Luthcke et al. 2012)

V12 (mascons iterated, corrected for geocenter, ICE5G and LIA/GIA correction for GOA)

Gravity: FGravity: Fgg = G( m = G( m11*m*m22)/r)/r22

Static gravity field

Photo by K. Steffen, U. of ColoradoNASA

Arctic & Antarctic Sea Ice

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Satellite Detection of Sea IceHigher rate of microwave emission from Higher rate of microwave emission from

sea ice than from open water. Emissivity sea ice than from open water. Emissivity indicated is for wavelength of 1.55 cm/19 indicated is for wavelength of 1.55 cm/19 GHz. 22 GHz & 37 GHz used for water GHz. 22 GHz & 37 GHz used for water vapor corrections. vapor corrections.

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Arctic Sea Ice studied since the 1950s…

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Arctic Sea Ice Minima Update

19 GHz, 22 GHz, & 37 GHz

Antarctic Sea Ice Minimum Update

19 GHz, 22 GHz, & 37 GHz

Antarctica is a continent surrounded by ocean – the Arctic Ocean the opposite

Measured Surface Temperature the past 150 yearsMeasured Surface Temperature the past 150 years12 warmest years are still: 1998 & 2001-201112 warmest years are still: 1998 & 2001-2011

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A UC Berkeley reanalysis effort funded in part by the Koch brothers

Global Atmospheric & Surface TemperaturesPassive microwave sensing at 22.8, 31.4, 50-58, 89-90, 150, & 183 GHz

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Dave Keeling

Historical data: Now = 2008

05,00010,000Time 33

The fraction of CO2 remaining in the air, after emission by fossil fuel burning, declines rapidly at first, but 1/3 remains in the air after a century and 1/5 after a millennium (Atmos. Chem. Phys. 7, 2287-2312, 2007).

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375

400

1950 1960 1970 1980 1990 2000 2010 20208.03

8.08

8.13

8.18

8.23

8.28

8.33

8.38

pH

Year

CO2

conc.(ppm)

CO2 Time Series in the North Pacific

CO2 = (1.738 ± 0.0293)x – 3105.9r2 = 0.94

pCO2 = (1.855 ± 0.224)x – 3364r2 = 0.310

pH = (-0.0019 ± 0.00025)x + 11.82r2 = 0.265

Mauna Loa atmospheric CO2 (ppmv)Aloha seawater pCO2 (µatm)Aloha seawater pH

Ocean Acidification from Increasing Atmospheric CO2 – Global Warming’s Evil Twin

From Richard A. FeelyNOAA/Pacific Marine Environmental Laboratory

Used with permission 35

Arctic Tundra Photosynthesis: Who?

GIMMS 3g NDVI set

and global NDVI trends

Temperature increases at higher northern latitudes:

Tundra photosynthesis, Sea ice, and Greenland surface melt

Arctic Tundra Biomass Work: How?

Arctic Tundra Biomass Work: Where?

Raynolds et al. 2012

Change in zonal Arctic phytomass

Arctic AVHRR-MODIS Comparison

Unequivocal Signs of Global Warming

• Night-time temperatures increasing more than day-time temperatures

• Winter temperatures increasing more than summer temperatures

• Upper atmosphere cooling & lower atmosphere warming

• Poles warming faster than equator• More extreme weather, more active

hydrological cycle

Climate & the Global Energy Balance

Through cosmic good fortune Earth has

retained water in the liquid phase for billions of years.

Climate sensitivity: very stable, slight initial forcing + feedback = glacial, inter-

glacial cycles. 43

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320

360

400

440

480

520

560

600

1900 1950 2000 2050 2100 2150

Atm

osph

eric

CO

2 (p

pmv)

Oil

Gas

Coal

Biosphere

Business-as-Usual(2% annual growth until 50% depletion, then 2% annual decline)

(deforestation)

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280

320

360

400

440

480

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560

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1900 1950 2000 2050 2100 2150

Atm

osph

eric

CO

2 (p

pmv)

Oil

Gas

Coal

Biosphere

Alternative Case: Coal Phaseout(+2%/yr to 2012; +1%/yr to 2022; linear shutdown between 2025-2050)

(deforestation)

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Climate Change?

Extra Material

Tropical Glaciers

“Ice asks no questions, presents no arguments, reads no newspapers listens to no debates.It is not burdened by ideology and carries no political baggage as it changes from solid to liquid. It just melts.”

From A World Without Ice by Henry Pollack, 2009

Nature’s best thermometer, perhaps its most sensitive and unambiguous indicator of climate change, is ice.

Areas Studied

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Cordillera Blanca Peru 2006 from ISSCordillera Blanca Peru 2006 from ISS

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New World Tropical Glacier area by elevation

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Formerly the World’s highest ski area

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Chacaltaya, Bolivia5,300 m/17,500’

Unequivocal Signs of Global Warming

Unequivocal Signs of Global Warming

Unequivocal Signs of Global Warming

Unequivocal Signs of Global Warming

Unequivocal Signs of Global Warming

Unequivocal Signs of Global Warming

June, July, & August 2011 were OFF THE CHARTS in Texas

Climate change?

Climategate: The Lion That Squeaked

Pounds CO2 per 1,000,000 BTUs

Natural Gas 115Petroleum 150Coal 220Tar Sands 250-290Oil Shale 300+2 phase changes takes a lot of energy!

Tar Sands—Dirty fuel, cook with CH4, requires double refining, uses huge quantities of water

Where does the heat go?

• oceans: 18.2 x 1022 J – warms the oceans • cryosphere: 1.1 x x 1022 J – melts ice water • atmosphere: 0.6 x 1022 J – warms the air

Sea Level & COSea Level & CO22/Temp from Ice Cores/Temp from Ice Cores

NASA’s Earth-NASA’s Earth-viewing viewing

satellitessatellites

Not pictured: Not pictured: SeaWiFS, SeaWiFS,

Landsat-5, and Landsat-5, and NOAA’s GOES & NOAA’s GOES & POES satellitesPOES satellites

What’s crucial?What’s crucial?Free & open Free & open data policy!data policy!

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