p. k. bhartia, omar torres, nickolay krotkov, richard mcpeters, joanna joiner nasa goddard space...

P. K. Bhartia, Omar Torres, Nickolay Krotkov, Richard McPeters, Joanna Joiner

NASA Goddard Space Flight Center

Greenbelt, Maryland, USA

Measurement of Atmospheric Constituents from Space: History & State-of-Art

Satellite Techniques

Nadir-Viewing Instruments•Back-scatter UV/VIS/SWIR•Thermal IR (TIR)

Limb-viewing Instruments•Occultation (solar, lunar, stellar)

– UV, VIS, TIR

•Limb Emission– TIR, Microwave

•Limb Scattering– UV, VIS, SWIR

Merged Total Ozone Time Series (Frith et al., JGR 2014)

60S-60N

30S-30N

Fit to Eqv. Effect. Strat. Cl (EESC)

Diurnal Variation of Ozone (MLO MWR)

3 hPa Ozone Time Series

60S-60N

30S-30N

SCIAMACHY

Profile Shape Error in TOMS Total O3

Nadir View, March (sza≈lat)

85˚ sza

75˚ sza

Estimated using ozonesonde climatology (mean & covariance)

Comparison of Tropospheric Column Ozone Derived by Combining MLS and OMI

2005-2012 JJA average

Data Assimilation Trajectory Method

Direct retrieval- no MLS Model

Assessment of Space-based O3 Measurements

• Total O3

– Quality of data from BUV instruments is now roughly comparable to that from Double Brewers, which are considered the “gold standard”.

• Strat O3 Profile– Limb/occultation instruments provide high quality data

above 20 km in tropics, 15 km elsewhere.

• Trop O3 Profile

– Good quality trop O3 column, but profile information is limited.

Volcanic SO2 Record

Operational Products

• O3 Vertical Profiles (cloud top to 60 km)– 7000/day, 84S-84N, daylight only

– ~1.8 km vert res, 1 km sampling

– Number density vs alt profiles are primary

– Mixing Ratio vs p produced using assimilated GPH and temp data from NASA GMAO, which compares well with Aura/MLS

– Aerosol scattering inde at 350, 510 & 650 nm

• Aerosol Profiles (cloud top to 35 km) – Extinction at 750 and 500 nm & size info

Decrease in SO2 over the Eastern US

The Ozone Monitoring Instrument (OMI) data confirm a substantial reduction in sulfur dioxide (SO 2) values around the largest US coal power plants as a result of the implementation of SO2 pollution control measures. The figure shows average SO2 values measured by OMI on the NASA Aura spacecraft for the periods 2005-2007 and 2008-2010 over the Eastern US where the majority of large SO2 sources are located. Scientists use this information to identify anthropogenic sources of SO 2 and to estimate their emission rates. The greatest values are in violet; the lowest in green. Yellow to violet colors correspond to statistically significant enhancements in SO2 pollution in the vicinity of largest SO2 emitting coal-burning power plants indicated by the black dots.

Previous use of space-based SO2 retrievals has been limited to monitoring plumes from volcanic eruptions and detecting anthropogenic emissions from large

source regions as in China. A new spatial filtration technique allows detection of individual pollution sources in Canada and US.

Mean SO2 values for 2005-2007 Mean SO2 values for 2008-2010

0 2.7 10 molecules/cmx 16 2

power plants

Fioletov, V., et al., (2011), Geophysical Research Letters,

Increase over India

Lu, Zifeng, David G. Streets, Benjamin de Foy, and Nickolay A. Krotkov, Ozone Monitoring Instrument Observations of Interannual Increases in SO2 Emissions from Indian Coal-Fired Power Plants during 2005−2012, Environmental Science and Technology, 2013

There has been a rapid decrease in NO2 pollution in the US.

Rate of decrease in the past decade is - 4%/year.

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• Chinese NOx emissions and NO2 pollution is growing almost at a pace similar to the nation’s GDP: +7%/year

• NO2 pollution over India is also increasing +2%/year.

SNPP/Ozone Mapping & profiler Suite (OMPS)

nadir profiler

nadir mapper

limb profiler

Launched Oct 28, 2011 on Suomi NPP

Limb Scattering Technique

Line of sightTangent point

Tangent heightDiffuse upwelling radiation

Solar Radiation

Comparison with Aura MLS- Center slit

% difference (LP- MLS)

The current LP algorithm doesn’t have an explicit correction for strat aerosols

Comparison with ACE-FTS

__LP, __ACE

% Difference (LP-FTS) Diurnal effect: negative differences above ~45 km, positive near 40 km.

Std Dev of difference (%)

Comparison with High Trop Ozonesondes

35N, 87W21S, 56E

LP has ~ 1.8 km vertical and ~200 km horizontal res

Comparison with Payerne (47N, 7E) Ozonesondes

Comparison with Antarctic Ozonesondes

71S, 8W 69S, 40E

Aerosol Extinction Profiles- March 2013

Log Scale Linear Scale

Planned Instruments with BUV capability

• Deep Space Climate Observatory (DSCVR): Launch early 2015– Located at 1st Lagrange Point (1.5 million km from

Earth along the sun-earth line) to provide hourly global coverage- useful for erythemal UVB

• Sentinel 5P/TropOMI (~2016)– OMI-like products with 7 km horizontal resolution

• Geostationary Instruments (2018-2020)– TEMPO (US), GEMS (S. Korea), Sentinel 4 ( ESA)

Comparison of Satellite Total O3 Record (30S-30N)

OMI

GOME/SCIA

SBUV

GOME/SCIA-SBUV OMI-SBUV

OMI/SBUV Differences are due to use of different O3 abs x-section

High Latitude Comparison (55N-60N)

GOME/SCIA-SBUV OMI-SBUV

Key ConclusionQuality of total O3 record from satellite BUV sensors is becoming comparable

of that from best quality ground station

Altitude vs. Distance Along LOS

1.5 km

196 kmTangent Ht.

x

z

IFOV

x