1. Satellite passive
microwave
measurements of
the climate crisis
Chelle Gentemann
Oceanographer
Remote Sensing Scientist
Pangeo Open Science Community
pangeo.io
ChelleGentemann
cgentemann
1

2. https://mishtalk.com/economics/hurr
icane-forecasts-may-revert-to-1970-
accuracy-due-to-5g-conflict
Ocean
temperature

3. https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.nature.com%2Farticles%2Fs41558-018-0318-3&psig=AOvVaw34ZEGG4C9eW725qRNqUel
F&ust=1633033643541000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCKiIw8mCpfMCFQAAAAAdAAAAABAJ
Trends in snow cover
Soil Moisture
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.semanticscholar.org%2Fpaper%2FApplications-of-microwave-remote-sensing-of-soil-Lakh
ankar-Krakauer%2Ffe813d15d54130ae6259f1e51aff099a83504e13&psig=AOvVaw0ycX8ZlgeRw09Tyr0dcgm-&ust=1633035233188000&source=image
s&cd=vfe&ved=0CAsQjRxqFwoTCJCP272IpfMCFQAAAAAdAAAAABAD
Sea Ice
Coral Reef

4. The PMW climate record 1987 - present
Data utilized by virtually every operational
NWP center in the world: NCEP, NHC, US
Navy, UK Met Office, ECMWF, Meteo-France,
JMA, AUS BOM, India NCMRWF…..
Kang, C., et al. (2020). Global Soil Moisture Retrievals From the Chinese
FY-3D Microwave Radiation Imager. IEEE Transactions on Geoscience and
Remote Sensing. PP. 1-15. 10.1109/TGRS.2020.3019408.

5. Microwave spectrum
Different parts of the microwave spectrum react differently to changes in the geophysical parameters.
Lower frequencies are sensitive to the surface and much less affected by atmosphere (which is the reason why they
are used for telecommunication).
Higher frequencies are sensitive to the atmosphere (water vapor, clouds) and see very little radiation from the surface.
Atmospheric temperature profiling by microwave sounders sensitive to oxygen absorption band (50 – 60 GHz).

6. Changing by Alisa Singer
"As we witness our planet transforming around us we watch, listen, measure … respond."
www.environmentalgraphiti.org – 2021 Alisa Singer.
AR6 Climate Change 2021:
The Physical Science Basis

15. Image credit: NOAA

16. Climate impact
drivers
PMW data
contributions
17 out of 35
variables

17. What have we learned since AR5 (2013)?
A plain language summary: Stuff is bad, we have to do something now.
We now have 50 years of LandSAT, 40 years of PMW ----- long enough to start to
understand variability….
AR6 new: A dedicated chapter to extreme weather events, which have been linked
with greater confidence to rising temperatures.
PMW data are critical to understanding accuracy of climate predictions, improving
climate parameterizations, especially as the next generation of models move
towards higher spatial resolutions
CarbonBrief prepared a comparison between the two reports. New AR6 topics are not included.
https://www.carbonbrief.org/ipcc-how-the-ar6-wg1-summary-for-policymakers-compares-to-its-predecessor

18. Arctic sea ice
AR5: E.5 A nearly ice-free Arctic Ocean
in September before mid-century is likely for
RCP8.5 (medium confidence). A projection of
when the Arctic might become nearly ice-free
in September in the 21st century cannot be
made with confidence for the other scenarios.
AR6: B.2.5 The Arctic is likely to be
practically sea ice-free in September at least
once before 2050 under the five illustrative
scenarios considered in this report, with more
frequent occurrences for higher warming
levels.
RFI - impact low

19. Arctic Amplification
AR5: E.1 The Arctic region
will warm more rapidly than
the global mean (very high
confidence).
AR6: B.2.1 It is virtually
certain that the Arctic will
continue to warm more than
global surface temperature,
with high confidence above
two times the rate of global
warming.
Dataset innovations, particularly more comprehensive representation of polar regions, and the availability of
new datasets have led to an assessment of increased global surface temperature change relative to the
directly equivalent estimates reported in AR5
RFI - impact limited

20. Hydrological amplification
AR5: E.2 Changes in the global water
cycle in response to the warming over
the 21st century will not be uniform.
The contrast in precipitation between
wet and dry regions and between wet
and dry seasons will increase, although
there may be regional exceptions.
AR6: B.3.2 There is strengthened
evidence since AR5 that the global
water cycle will continue to intensify as
global temperatures rise (high
confidence), with precipitation and
surface water flows projected to
become more variable over most
land regions within seasons (high
confidence) and from year to year
(medium confidence).
RFI - impact high

21. Heat Extremes
AR5: E.1 It is virtually certain
that there will be more frequent
hot and fewer cold temperature
extremes over most land areas
on daily and seasonal
timescales as global mean
temperatures increase. It is very
likely that heat waves will occur
with a higher frequency and
duration.
AR6: B.2.2 Every additional
0.5C of global warming causes
clearly discernible increases in
the intensity and frequency of
hot extremes, including
heatwaves (very likely).
RFI - impact low-med

22. Drought Extremes
AR5: SPM.1 Increases in intensity and/or duration
of drought: Low confidence [for the early 21st century];
and likely (medium confidence) on a regional to global
scale [for the late 21st century].
AR6: B.2.2 Discernible changes in intensity and
frequency of meteorological droughts, with more regions
showing increases than decreases, are seen in some
regions for every additional 0.5C of global warming
(medium confidence). Increases in frequency and intensity
of hydrological droughts become larger with increasing
global warming in some regions (medium confidence).
RFI - impact high

23. Rainfall Extremes
AR5: E.2 Extreme precipitation events over most
of the mid-latitude land masses and over wet
tropical regions will very likely become more
intense and more frequent by the end of this
century, as global mean surface temperature
increases.
AR6: B.2.4 It is very likely that heavy precipitation
events will intensify and become more frequent in
most regions with additional global warming. At
the global scale, extreme daily precipitation
events are projected to intensify by about 7% for
each 1C of global warming (high confidence).
RFI - impact high

24. Marine Extremes
Sustained periods of anomalously high
near-surface temperatures that can lead to
severe and persistent impacts on marine
ecosystems – have become more frequent
over the 20th century (high confidence).
Since the 1980s, they have approximately
doubled in frequency (high confidence) and
have become more intense and longer
(medium confidence).
https://www.frontiersin.org/articles/10.3389/fmars.201
9.00734/full
RFI - impact high

25. Cyclone Activity
AR5: SPM.1 Increases in intense tropical
cyclone activity: Low confidence [for the early
21st century]; and likely (medium confidence)
on a regional to global scale [for the late 21st
century].
AR6: B.2.4 The proportion of intense
tropical cyclones (categories 4-5) and peak
wind speeds of the most intense tropical
cyclones are projected to increase at the
global scale with increasing global warming
(high confidence).
The observed trend in the number of tropical cyclones per year from
1980-2018. Red to yellow indicates an increase in the number of
cyclones per year, while purple to green indicates a decrease.
Source: Murakami et al. (2020)
RFI - impact low

26. https://mishtalk.com/economics/hurr
icane-forecasts-may-revert-to-1970-
accuracy-due-to-5g-conflict
Ocean
temperature
Affected
by RFI

27. Ocean RFI
● ground / ship based
○ Ascension Island, Hawaii, Netherlands
● GeoStationary Satellites
○ Media Broadcasts (TV, Radio)
■ Power
■ Direction
■ Frequency
● *Glint Angle*
○ A.K.A. “RFI Angle”

28. Land RFI
Land emission - primarily in 7GHz channel
This image from 2002, yes it is much worse
now.
SMOS:
“The transmissions contaminating the data
were due to two main reasons: either
emissions in adjacent bands that were
leaking into the protected region owing to
excessive power levels, or illegal
transmissions within 1400-1427 MHz”
Fig. 1. Global maps of means of AMSR-E
brightness temperature spectral difference
(RI = T B T B ) for July 2002. The statistics
are derived by aggregating data within 0.25
latitude and longitude bins. Color scale units
are in Kelvins
https://trs.jpl.nasa.gov/bitstream/handle/2014
/40892/04-1697.pdf?sequence=1
https://www.space.com/9294-blinded-satellite-gains-ground-radio-i
nterference-battle.html

29. Wideband Radiometry:Interference
*courtesy, SMOS ESA

30. Land RFI over Japan
● Human Radio-Frequency Interference (RFI) is an increasing threat to remote
sensing measurements globally
● Faulty cable boxes in installed in Japan, suddenly made soil-moisture science
unattainable over the whole country
* courtesy, SMOS RFI report
Slide: Sid Misra

31. RFI at higher frequencies
*courtesy, McKague et al.,** courtesy, D. Draper
2004 2007 2009
RFI as observed by AMSRE (top) and GMI (bottom) at 19
GHz, due to Geostationary Satellite TV
Slide: Sid Misra

32. Both 11 and 19 GHz over land and ocean
Only affects either asc or dsc passes, but not both (geometry)
Growing problem, but possible solution

33. Threats to Remote Sensing
Slide: Sid Misra

34. Climate impact
drivers
PMW data
contributions
17 out of 35
variables

35. Weather • PMW contributing up to
25% in skill of forecast
Microwave Measurements
*courtesy, Earth Science and Applications from Space.

36. Passive Microwave data for Climate

37. Passive Microwave Needs
- Mesh antenna to increase spatial
resolution (~50km to ~10 km)

39. 70% of the world is covered by the ocean which
provides heat and moisture to the atmosphere drivin
weather and climate variability
Passive Microwave Needs
https://goodmorninggloucester.com/2021/06/11/early-morning-sea-fog-over-the

40. At the ocean surface, the exchange of heat and moisture fuel
atmospheric weather and climate and ocean variability.

41. This can shift
regional weather
patterns
Affecting weather
across the U.S.
Models show us
that….
storms in the Eastern
Pacific respond to 25
km air sea fluxes
Archambault et al., 2013
This also happens in the Gulf Stream / Europe