Atmosphere Monitoring

Global data assimilation of Sentinel 5p O3 retrievalsAntje Inness (ECMWF) & the CAMS team

AtmosphereMonitoring • CAMS provides global 5-day forecasts of atmospheric composition

twice every day

• Horizontal resolution about 40 km x 40 km

• Data assimilation is used to provide the best possible initial conditions for these forecasts

• Assimilated species in NRT: O3, CO, NO2, SO2 & AOD

• GHG system (CO2 &CH4) that runs a few days behind NRT (See talk Jérôme Barré)

• Reanalysis of atmospheric composition (2003 - onwards) available from atmosphere.copernicus.eu

I n t r o d u c t i o n

AtmosphereMonitoring

A t m o s p h e r i c c o m p o s i t i o n d a t a u s e d i n N R T

Instrument Satellite Provider Type

MLS AURA NASA O3 ProfilesOMI AURA NASA O3 Total columnGOME-2 Metop-AB Eumetsat O3 Total column

SBUV-2 NOAA-19 NOAA O3 layersOMPS Suomi-NPP NOAA /

EUMETSATO3 Profiles

TROPOMI S5P ESA O3 Total column

IASI MetOp-AB LATMOS/ULB Eumetsat

CO Total column

MOPITT TERRA NCAR CO Total column

OMI AURA KNMI NO2 Tropospheric column

GOME-2A/2B METOP A/B Eumetsat NO2 Tropospheric column

GOME-2A/2B METOP A/B Eumetsat SO2 Tropospheric column

MODIS AQUA / TERRA NASA AOD,fire radiative power

PMAp METOP-AB EUMETSAT AOD

StatusSeptember 2019

Atmosphere Monitoring 2019 Ozone hole

AtmosphereMonitoring

2 0 1 9 o z o n e h o l e

2019 ozone hole is • very unusual• exceptionally small• displaced off the pole• well forecast by CAMS

Calculated for area south of 60⁰S

< 220 DU

AtmosphereMonitoring • Chemical ingredients: Ozone depleting substances (e.g. CFCs)

• Isolated conditions: Polar Vortex• Low temperatures (<-78⁰C):

– Formation of Polar Stratospheric Clouds (PSCs)– Reaction on surfaces of PSCs convert reservoir species to more active species

(e.g. ClO) => enhancing O3 depletion– PSCs can lead to denitrification (i.e. removal of NOx that could convert ClO

back into reservoir species ClONO2)

• Sunlight: O3 depletion begins when sunlight returns to polar region

• End of O3 hole:– End of SH spring/early summer– Warming destroys PSCs and breaks down the vortex => mixing in of O3 rich

air and mixing out of O3 poor air

I n g r e d i e n t s f o r O z o n e h o l e f o r m a t i o n

AtmosphereMonitoring • Stratosphere warms (can be 50⁰C in a few days) and polar vortex

weakens

• Major sudden Stratospheric Warming (SSW) if winds reverse to easterlies and vortex breaks down

• Planetary scale waves from the troposphere can propagate into stratosphere during winter where they dissipate

• More common in NH where circulation is more disturbed (orography, land sea contrast)

• Last major SSW in SH was in 2002 when polar vortex split

• Currently SH is experiencing a (major?) SSW

• Polar vortex is ‘pushed’ away from the Pole and stratosphere considerably warmer than usual

S u d d e n S t r a t o s p h e r i c W a r m i n g

25 Sep 2002

AtmosphereMonitoring

S t r a t o s p h e r i c T e m p i n S e p 2 0 1 9 & 2 0 1 8

16 Sept 2019 16 Sept 2018

AtmosphereMonitoring

Z o n a l m e a n T e m p e r a t u r e a t 1 0 h P a

1 Aug – 16 Sept 2019 1 Aug – 16 Sept 2018Zonal mean T in ⁰C

• Polar vortex weakens (more mixing)• Amount of PSCs reduced Weaker/ smaller ozone hole

Total column O3 from CAMS on 16 September 2019 and 2018

Dobson Units

16 September 2019 16 September 2018

Ozone and temperature profiles at South Pole from CAMS and ozone sondes on 8 Sept 2019 and from climatology

Temperature [⁰C]

8 Sep 2019

8 Sep 2019

Ozone [mPa]

2003-2018 climatology

2003-2018 climatology

Climatology from CAMS reanalysis 2003-2018:atmosphere.copernicus.eu

Ozone and temperature profiles on 4 September 2019 at Marambio and Belgrano

Ozone [mPa] Temperature [⁰C]

SondeMarambio

SondeBelgrano

Dobson Units

Ozone column 4 September 2019

x x

AtmosphereMonitoring • CAMS ozone analyses and forecasts agree well with ozone sondes

• 2019 ozone hole is exceptionally small

• Likely to be one of the smallest since 1980s

• Meteorological/ dynamical reasons: Sudden Stratospheric Warming in SH

• Not a sign that ozone hole problem is solved!

• Forecast for the next 5 days

O z o n e h o l e s u m m a r y a n d o u t l o o k

AtmosphereMonitoring • CAMS ozone analyses and forecasts agree well with ozone sondes

• 2019 ozone hole exceptionally small

• Likely to be one of the smallest since 1980s

• Due to meteorological/ dynamical reasons: Sudden Stratospheric Warming in SH

• Not a sign that ozone hole problem is solved!

• Forecast for the next 5 days

O z o n e h o l e s u m m a r y a n d o u t l o o k

AtmosphereMonitoring

M o r e i n f o r m a t i o n

• More info about the ozonehole: atmosphere.copernicus.eu/monitoring-ozone-layer

• Satellite monitoring plots on: atmosphere.copernicus.eu/charts/cams_monitoring/

AtmosphereMonitoring

S u d d e n S t r a t o s p h e r i c W a r m i n g 2 0 1 9

Temperature and geopotential at 10 hPabetween 1 Aug – 16 Sep 2019