With the installation of two airglow spectrometers, one at Mallorca, Spain and one at Sicily, Italy, in autumn 2011 the CESAR measurement campaign has successfully started. Its goal is the investigation of atmospheric wave signatures generated by severe weather in the Mediterranean.

The emission of gravity waves and infrasound by severe weather cyclones is investigated within the project CESAR ("Charakterisierung des differentiellen Energiegehaltes von Vb-Zyklonen ueber die Quantifizierung abgestrahlter Schwere- und Infraschallwellen in der Atmosphaere"). The change of the energy content of these atmospheric waves is supposed to be a direct measure for the changing energy content of a cyclone. It is investigated within a measurement campaign whether this so-called "differential energy content" of a cyclone can be recorded in the stratosphere and mesopause by the observation of atmospheric wave dynamics in radiosonde, airglow spectrometer and satellite based measurements.

Data from four GRIPS ("Ground-based infrared P-branch spectrometer") instrument sites, two radiosonde starting facilities and satellite overpasses are used within the campaign. Measurements are performed at Palma de Mallorca, Spain, in Catania, Italy and at the UFS Schneefernerhaus, MOH Hohenpeissenberg as well as at DLR Oberpfaffenhofen in southern Germany (see map). The GRIPS data are available at WDC-RSAT using the following link: NDMC Operational Data Products page.

CESAR is funded by the Bavarian State Ministry of the Environment and Public Health (BayStMUG) and performed by the German Aerospace Center (DLR) in cooperation with the University of Augsburg (UNA). The project started in November 2009 and has a duration of three years, including a measurement campaign as described above. Cooperation partners within this campaign are the Agencia Estatal de Meteorologia (AEMET, Spain), the Istituto Nazionale di Geofisica e Vulcanologia (INGV, Italy), the Deutscher Wetterdienst (DWD, Germany), the Zentralanstalt fuer Meteorologie und Geodynamik (ZAMG, Austria) and the Applied Physics Laboratory (APL, USA).

For more information please contact wdc@dlr.de.

Applying the GOME-2 instrument on MetOp-A enables a quantification of the SO2 amounts detected in the vicinity of the Islandic volcano. For this analysis, the total SO2 mass detected by GOME-2 in the region from 120° West to 30° East and from 40° to 80° North was integrated. Beginning on May 22nd the amount SO2 increased to up to 500 kilotons. The intensity of Grimsvötn’s eruption decreased after May 23rd, leading to a decrease of the SO2 residing in the atmosphere. The integration of the SO2 mass was performed on the basis of level 2 (L2) data which are routinely processed at DLR on behalf of EUMETSAT. To determine the SO2 mass correctly, the applied algorithm accounts the measurement with the optimal observation geometry (disregarding further measurements that took place at the same geolocation).

For more information please contact wdc@dlr.de.

The GOME-2 SO2 data can be accessed via
http://wdc.dlr.de/data_products/SERVICES/GOME2NRT/so2.php

The 4th NDMC meeting will be held from 10-12
May, 2011 at DLR in Oberpfaffenhofen in Bavaria, Southern Germany. Main topics of the meeting will be a status report, presentations on results of the NDMC campaign on gravity waves and other scientific results including technological innovations, reports on the NDMC thematic areas, and discussion about how to further develop NDMC.

For more information:
1st-Announcement.pdf
Preliminary Agenda

Network for the Detection of Mesopause Change (NDMC) http://wdc.dlr.de/ndmc

For more information please contact wdc@dlr.de.

The first NDMC InterComparison Campaign (NICC-1) has been started at the Observatory ALOMAR in Norway initiated by the German Remote Sensing Data Center (DFD) of the German Aerospace Center (DLR). The Infrared-Spectrometer GRIPS 9 (Ground-based Infrared P-branch Spectrometer) was successfully installed at ALOMAR in November 2010 and measures OH temperatures in the mesopause region at about 87 km height. These measurements will be continued until April 2011 in order to inter-compare the GRIPS results with collocated temperature measurements from other OH-spectrometers and OH-imagers as well as lidars and satellite-based instruments. The results of NICC-1 will be published on the NDMC website. The Figure shows the first measurement of GRIPS 9 in ALOMAR, Norway.

Full article

Network for the Detection of Mesopause Change (NDMC) http://wdc.dlr.de/ndmc

NRT Quicklooks are available on the NDMC website: http://wdc.dlr.de/ndmc/content.php?mId=204&cId=110

For more information please contact wdc@dlr.de.

Anyone wanting to enter the city centre of Munich by car after October 1st 2010 should have a green or yellow emission sticker on the windscreen of his car. From that day on the next stage of the clean air plan of the city of Munich will be activated. The goal is to improve the air quality in Munich in accordance with regulations set up by the European Union.

Full article

Air quality forecast data for Bavaria can be accessed via http://wdc.dlr.de/data_products/projects/promote/BY-forecast/

Air quality forecast are provided daily for the following 72 hours. The system is based on the POLYPHEMUS/DLR air quality system and the WRF-model for meteorological simulation.

Forecasts are also available as overlays to GoogleEarth using this file.

Wintertime in the southern hemisphere is in full swing: The “precursor” of an ozone hole, a boiler shaped vortex over the South Pole has developed, preventing exchange of air masses between polar and middle latitudes. Daily analyses of GOME-2 data, evaluated at DLR on a routine basis on behalf of EUMETSAT and assimilated at DFD into a 4D-Var-Model, show that this polar vortex does not stay symmetrical to the pole but is being deformed continuously: Similar to the dough of a cake the air mass in this boiler above the South Pole is being kneaded all the time. For scientists this is of significant interest, as large-scale waves in the atmosphere, so-called planetary waves, are responsible for these deformations. There is some evidence that due to climate change the intensity of these waves will be changed, going along with changes of the global air flow pattern.

Full article

For more information please contact wdc@dlr.de.

Figure: 84h trajectory analysis of hypothetical particles started on 13 August 2010 12UTC between 0 and 1000m in the region of Bryansk (53.3°N, 34.4°E), based on GSF data.

Due to high temperatures of more than 40°C and the absence of precipitation the forest and peat fires in Russia could not be stopped so far. In case that radioactive particles originating from the nuclear reactor disaster of Chernobyl in 1986 have been risen up into the atmosphere by the strong fires, they may be undergo long-range transport. The 84h trajectory analysis of DLR shows the dispersion of hypothetical particles emitted in the region of Bryansk between surface and 1000 m on 13 August 2010 at 12UTC. The forecast reveals that the particles are transported in north-western and northern directions independently of their emission height and that they will have reached the Baltic Sea 24 hours after their release. Afterwards a separation takes place depending on their travel height. Particles in the lower atmospheric layers are transported in northern direction. Particulate matter that is uplifted into higher tropospheric layers due to the prevailing meteorological conditions follow the winds to northern and eastern directions.

For more information please contact wdc@dlr.de.

Latest near-real time data from MetOp/GOME-2 reveals a very impressive SO2 plume from Iceland towards Ireland. The maximum content of SO2 is about 9 Dobson Units. During the last few days a significant reactivation of the SO2 emissions by Eyjafjalla could be observed.

From NOAA-19 AVHRR data received on April 20th in the early morning before sunrise (5:54 CEST) hotpots can be seen for the first time. The red arrows point at two green-blueish coloured areas, a larger and a smaller one. Such hotspots can be identified through the use of a mid-infrared channel (wavelength: 3.7 µm), since an increase of the temperature generally results in a high signal response in this spectral region. The obvious intensification and extension of the hotspots indicate that Eyjafjalla potentially started to eject more lava and therefore less amount of ashes.

Daily NRT Cloud Coverage by APOLLO NOAA/AVHRR can be found in the WDC-RSAT data base:
http://wdc.dlr.de/apollo/index.php

Archives directories with all scenes processed so far start here.

This study shows the air masses being emitted from the volcano Eyjafjallajökull residing over Europe during the time of DLR-Falcon's flight at 19 April, 2010. The flight took place between 16:00 and 19:30 local time. The color code represents the actual height of the considered air parcels.

Data base: Data GFS/NCEP Analyses and Forecasts; Model FLEXTRA, 3D, kinematic

DLR operates the cloud physical parameter APOLLO (AVHRR/MSG Processing scheme Over cLouds Land and Ocean) processing scheme for EUMETSAT's METEOSAT-9 meteorological satellite. Low sun elevation conditions in morning and late afternoon hours allow the visualization of atmospheric turbidity with its spatial variability.

The time-series is available for download via the following link (zip-file, 6MB): --> click here

The time-series is available in jpg-format here.

The combination of satellite observations and atmospheric transport modelling can provide crucial information on the dispersion and transport of ash and trace gases. Besides ash also water vapour, carbon dioxide and sulphur dioxide are emitted by volcanic eruptions. Since water vapour and carbon dioxide are quite abundant in the atmosphere and high concentrations of SO2 are mainly linked to volcanoes, SO2 is a very good indicator for volcanic activity. SO2 total columns can be retrieved from GOME-2 aboard MetOp. At DLR GOME-2 data are processed routinely and atmospheric SO2 total columns are retrieved in near-real time and with a global coverage in about one day. The images show the distribution of SO2 over Iceland and Northern Europe from April 15 to 19, 2010. The movement of the plume to the east and south east with the prevailing winds can be seen. However, the GOME-2 SO2 observations and the volcanic ash index from MSG only provide a two-dimensional snapshot of the SO2 plumes. In order to derive information on the plume height, the emission source, the time of the emission and the future dispersion of the plume a trajectory ensemble matching technique. The plume height over Germany can be estimated to 4 to 8 km. Different ground-based observations of significantly elevated particulate matter and SO2 values, could already been traced back to the Eyjafjalla volcano. Finally, by means of this methodology the planning of the DLR FALCON flight on April 19, 2010 was supported.

For more information please access the GOME-2 SO2 data via
http://wdc.dlr.de/data_products/SERVICES/GOME2NRT/so2.php

AVHRR data from the NOAA series of satellites is routinely being received at the German Remote Sensing Data Center (DLR-DFD). This satellite image, acquired on April 17, 2010 by NOAA-19, shows the ash emitted by the volcano Eyjafjallajokull in Southern Iceland as a blue-greyish cloud formation. Being diverted first in a southern direction by Northern winds, the cloud drifted southeastwards due to winds caused by a low pressure system east of Iceland. Due to its dispersion above Central Europe, the ash cloud is not as visible as directly above the crater.

Daily NRT Cloud Coverage by APOLLO NOAA/AVHRR can be found in the WDC-RSAT data base:
http://wdc.dlr.de/apollo/index.php

Archives directories with all scenes processed so far start here.

There is evidence for the approaching end of the winter also in the stratosphere:
Large-scale dynamic activity has been increasing since mid December 2009 and seems to collapse during the next days - an indication for the reversal from winter to summer circulation.

Full article

For more information on the Dynamic Activity Index (DAI) based on OMI data please visit
http://wdc.dlr.de/data_products/DYNAMICS/dai_latest.php

Total Column Ozone based on OMI data:
http://wdc.dlr.de/sensors/omi/

For more information on the Network for the Detection of Mesopause Change (NDMC), please visit: http://wdc.dlr.de/ndmc

From September 01 to October 31, 2009, the first global NDMC (Network for the Detection of Mesopause Change) measurement campaign has been successfully conducted, over 20 members of the international NDMC association participated in this global experiment. The main objective of this campaign was to investigate hemispheric asymmetries and planetary wave activities in the mesopause region deriving the intensity and temperature from the OH and O2 emissions in the airglow layer using optical instruments such as spectrometers and photometers.
The World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT), which is hosted by the German Remote Sensing Data Center (DLR-DFD) has been designated as the NDMC data center and served as the data and communication platform during the campaign. The scientific results of the campaign will be presented and discussed at the next NDMC Meeting in May, 10-14, 2010.
NDMC is a global program with the mission to promote international cooperation among research groups investigating the mesopause region (80-100 km) in order to reliably detect and monitor climate change signals. NDMC will conduct regular global NDMC campaigns once a year usually at the equinox period focusing on the coordinated investigation of atmospheric variability at all time scales and the development of improved measurement methodologies, analysis and modelling techniques. The initial emphasis is on mesopause region airglow techniques utilizing the existing ground-based and satellite measurement capabilities.

Link to the BMDI publication:
Klüser and Schepanski, Rem. Sens. Environ., 113, 2009

A new mineral dust product for Meteosat Second Generation (MSG), the Bitemporal Mineral Dust Index (BMDI), has been developed at DLR-DFD providing five years of daily dust observations from MSG.
While traditional aerosol optical depth retrievals do not distinguish between the contributions of different aerosol species to the total aerosol signal, the BMDI is sensitive to mineral dust only and thus can be used to analyse effects directly connected to the presence of mineral dust. Such effects include e.g. aerosol cloud interactions and their impact on precipitation, where the aerosol type is a crucial factor.
The image shows five years of BMDI (30 day running mean) together with precipitation observations (from the Tropical Rainfall Measuring Mission) over the West-African Sahel region, where mineral dust is reported to have a great influence on monsoon strength and desertification. The BMDI dataset, covering five years, provides the ability to separate the effects of dust and of other aerosols such as from biomass burning on cloudiness and precipitation; e.g. one focus of aerosol-cloud-interaction studies at DLR-DFD is the reduction of Sahelian monsoon precipitation by Saharan dust.

On September 01, 2009, the first global NDMC (Network for the Detection of Mesopause Change) measurement campaign has started. The main objective of this campaign is to investigate primarily hemispheric asymmetries and planetary wave activities in the mesopause region. Prime focus will be on the intensity and temperature derived from the OH and O2 emissions in the airglow layer using optical instruments such as spectrometers and photometers. It will be completed by October 31, 2009. The World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT) will serve as the data and communication platform for the campaign.

For more information on NDMC, please visit: http://wdc.dlr.de/ndmc

During a ceremony on July 22, 2009 at the World Meteorological Organization (WMO) in Geneva a „Memorandum of Understanding“ (MoU) was signed designating the World Data Center for Remote Sensing of the Atmosphere (WDC-RSAT) operated by the German Remote Sensing Data Center (DFD) as an official World Data Center of the WMO. The document was signed by the CEO of the German Aerospace Center (DLR), Prof. Wörner, the Secretary General of WMO, Dr. Jarraud, and the Director of the German Remote Sensing Data Center (DFD), Prof. Dech. Also present was the President of the Deutscher Wetterdienst (DWD), Mr. Kusch, in his capacity as the Permanent Representative to WMO for Germany.

Full article

The Normalized Difference Vegetation Index (NDVI) is a measure of the greenness of vegetation. Data from the Advanced Very High Resolution Radiometer (AVHRR) sensor on board of the NOAA weather satellites are received and processed at DLR-DFD on a daily time step since the beginning of the 1990. DLR-DFD uses these data to derive the NDVI as daily, weekly, 10-days (decadal) and monthly composites.
Calculating the mean NDVI for the decadal composites of each month a reference NDVI composite can be derived which can be regarded as the mean greenness of the vegetation. Subtracting the actual decadal composite and the reference decadal composite gives a view on the growth characteristics in comparison to the long term mean (anomaly).
The NDVI anomaly for the time span from May 1st to May 10th, 2009, over central Europe reveals an unusual warm and rainy beginning of May shown as an increase in the actual decadal NDVI of up to 0.2 NDVI value.

Full article

Fig.1: GOME-2 measurements of SO2

Fig.2: 60 hours forecast of the SO2 plume

After an inactive phase of 20 years Alaska’s Mount Redoubt volcano erupted explosively on 23rd March 2009 at 5:38 UTC. Four further eruptions followed. Each of these eruptions lasted 4 to 20 minutes and sent ash clouds up to 15-18 km. The ash has been moved northward due to the wind direction. For safety reasons Alaska Airlines cancelled 19 flights out of Anchorage, the most populous city in Alaska.
Measurements of the GOME-2 (Global Ozone Monitoring Experiment) instrument on board MetOp reveal large amounts of sulphur dioxide (SO2) ejected by the volcano (Fig. 1). As part of a volcano activity monitoring service DLR-DFD provides forecasts of the time-spatial distribution of the volcanic ash and SO2-cloud. Figure 2 shows a 60 hours forecast based on forward trajectory ensembles started between 0 and 20 km above sea level. Three days after the first eruption ash particles and trace gases that have been lifted up above 15 km will reach the middle of the state Alberta, Canada.

Mount Redoubt volcano is still unstable and further eruptions are expected.

For more information please contact wdc@dlr.de
or access the GOME-2 SO2 data via http://wdc.dlr.de/data_products/SERVICES/GOME2NRT/so2.php

An aerosol retrieval method called Synergetic Aerosol Retrieval (SYNAER) applied to MetOp instruments AVHRR/GOME-2 was combined with a chemical transport model MATCH/DLR with the help of an advanced data assimilation procedure. Based on Desroziers et al., 2001 newly adapted background and observation error covariance matrices were used to characterize the relative weighting of data and model in this case study.

Full article

Stratospheric warmings are one the most dramatic phenomena of the atmosphere: this spontaneous warming of the winter stratosphere is sometimes even linked to a reversal of the large scale circulation.

Full article

GOME-2 images and value added products are available at WDC-RSAT:
http://wdc.dlr.de/sensors/gome2

On 4th November 2008 the atmospheric sensor GOME-2 (Global Ozone Monitoring Experiment) detected a big SO2-plume over Yemen with sulphur dioxide amounts of more than 40 DU. So far no observation from ground nor any eye-witness have reported on the eruption. With the aid of backward trajectory analysis a trajectory density map was generated and so it was possible to derive further information about the eruption source and characteristics.
The images show the SO2 column over the volcanic region as measured by GOME-2 (left) and the corresponding trajectory density of the SO2-plume (right).
Following the analysis the source is located close to Erta Ale volcano in the dessert of Danakil in Ethiopia. At the north flank of Erta Ale are two small volcanoes called Alu and Dalaffilla which are the most probable eruption source.

The trajectory matching technique also enables to estimate the height of the SO2 plume and the eruption time. The sulphur dioxide plume reached heights up to 14 km. The eruption time window lies between 8 and 12 UTC on 3rd November.
For more information please contact wdc@dlr.de.

The GOME-2 SO2 data can be accessed via
http://wdc.dlr.de/data_products/SERVICES/GOME2NRT/so2.php

The O3M-SAF products from DLR: total O3, total NO2 and tropospheric NO2 from GOME-2 are being distributed regularly as pre-operational near-real-time and off-line products. These products already fulfill the user requirements and an initial validation was carried out.

The full operational status can be reached after the validation of a complete year of data is assessed. To this purpose, the O3M-SAF Operational Readiness Review Meeting (ORR-B) took place at DLR Oberpfaffenhofen in October 29-30. The review board recommended to upgrade the status of the product
- Total O3 (NTO/O3 and OTO/O3)
- Total NO2 (NTO/NO2 and OTO/NO2)
- Tropospheric NO2 (NTO/TropoNO2 and OTO/TropoNO2)
- Total SO2 (OTO/SO2)
to operational.

The O3M-SAF Steering Group will considerer the recommendation of the review board during the next meeting (25-26 Nov.) and take an official decision.

GOME-2 images and value added products are available at WDC-RSAT:
http://wdc.dlr.de/sensors/gome2

After being inactive for more than 200 years the Kasatochi volcano on the Aleutian Islands erupted on 07th August 2008 around 22:00UTC. An ash cloud spread out about 800 km in a counterclockwise spiral leading Alaska Airlines to cancel 44 flights between 10th to 11th August 2008. Apart from volcanic ash, the Kasatochi emitted large amounts of sulphur dioxide (SO2), an atmospheric trace gas. Whereas the ash particles got deposited after a few days, the trace gas dispersed throughout the whole northern hemisphere. The atmospheric sensor GOME-2 (Global Ozone Monitoring Experiment) delivered global near-real-time SO2 data showing the hemispheric transport of the SO2 plume and the formation of separate curls by the wind. The plume arrived over Europe on 14th August 2008 and took 7 more days for reaching Alaska again.

Further information you can get here:
http://wdc.dlr.de/data_products/SERVICES/GOME2NRT/so2.php

The Advanced Very High Resolution Radiometer (AVHRR) on board of the NOAA-18 satellite observes on a daily basis the status of the globe. The German remote Sensing Data Center (DFD) of the German Aerospace Center (DLR) receives the raw data of AVHRR in Oberpfaffenhofen for the European area and process the data to so called value added product. One product is the Sea Surface Temperature (SST) of the Mediterranean Sea representing the mean water temperature of each week (so called weekly composites).

The map shows the mean SST for the time period from July 28th to August 3rd, 2008. In the eastern part of the Mediterranean Sea and in the eastern part of the Black Sea the water temperature is above 30°C. In the western part of the Mediterranean Sea especially in the strait of Gibraltar cold water of about 15°C from the Atlantic flows toward the Mediterranean Sea.White areas are either land or water bodies with a temperature of 15°C (e.g. Gulf of Biscaya). The dark red color represents clouds (e.g in the Eastern part of the Black Sea). The highest water temperature is 29.25°C.

For more information on SST and for getting SST-products, please visit:
Sea Surface Temperature information page
SST Products

Total amount of nitrogen dioxide (NO2) in the atmosphere above Europe derived from one year of data from the GOME-2 instrument on Metop-A (March 2007 - February 2008).

The GOME (Global Ozone Monitoring Experiment)-2 scanning spectrometer on board Metop-A is now delivering hourly reports on the amount of nitrogen dioxide (NO2) in the Earth's troposphere. A sophisticated data processing system, which produces maps showing global NO2 concentrations based on processed GOME-2 data, was developed by the German Aerospace Center (DLR). NO2, together with aerosols and ozone, is one of the most important contributors to air pollution.

The GOME-2 NO2 products are available in near real time, i.e. 2 hours and 30 minutes after observation, making it possible to track changes in global tropospheric NO2 on a daily basis.

Further information you can get here:
DLR press release
WDC-GOME-2 sensor page
GOME-2 NRT Products - Tropospheric NO2 Column

Phytoplankton uses chlorophyll and light-harvesting pigments for absorbing incoming light. The absorbed energy is then transferred in a complex bio-chemical cycle to sugar integrating carbon dioxide (the process is called photosynthesis) dissolved in the water. When phytoplankton population increases under favourite conditions (e.g. availability of nutrients, light and optimal water temperature) the surface water gets coloured from brown to green and light-blue.

A similar algae bloom along the western coast of Ireland was observed last year in May 03, 2007. The algae bloom spreads about 600km from the north of Ireland to the south.

Further information you can get here:
WDC MERIS sensor page

Japan Aerospace Exploration Agency (JAXA), National Institute for Environmental Studies (NIES) and Ministry of the Environment (MOE) ("Three Parties") started Greenhouse gases Observation SATellite(GOSAT) Project some years ago. GOSAT project is contributing to GEOSS 10-Year Implementation Plan through GEOSS tasks: CL-06-02 "Key Climate Data from Satellite Systems", DA-07-03 "Virtual Constellations", and EC-06-01 "Integrated Global Carbon Observation (IGCO) ."

While the time of the launch of GOSAT is approaching in early 2009, the Three Parties issued a Research Announcement (RA) of GOSAT on April 7,2008.
This RA solicits a proposal for calibration, processing algorithm, validation, carbon balance estimation and application using GOSAT data.
If you are interested in it, please take time to visit following site:
http://www.gosat.nies.go.jp/eng/proposal/proposal.htm

The latest eruptions of Etna started on 10 May 2008 around 16:00 CEST. The first eruption lasted for about 4 hours and was dominated by heavy activity of the south-eastern crater.

Apart from the emission of lava, the eruption at Etna emitted large amounts of sulphur dioxide (SO2), a colourless and toxic trace gas, into the atmosphere. The SO2 was measured the day after the eruption, 11 May, by the atmospheric sensor GOME-2 (Global Ozone Monitoring Experiment) on the EUMETSAT satellite, MetOp-A. The SO2 plume had been transported eastwards and could be traced over Greece, with sulphur dioxide amounts of more than 20 DU. Trajectory analysis revealed that the sulphur dioxide was injected into the atmosphere by Etna up to a height of 12 km. The path of the volcanic cloud could be tracked for two more days as it moved further eastwards. On the third day after the eruption the sulphur dioxide cloud moved over Iran and the next day it could still be detected over Turkmenistan.

Further information you can get here:
DLR press release
WDC-GOME-2 sensor page
GOME-2 NRT Products - Total SO2 column

http://wdc.dlr.de/sensors/gome2/movies

Animations are based on GOME-2 Level 2 data which are operationally assimilated into the 3D-Chemical Transport Model ROSE/DLR.

This winter one minor ozone loss episode evolved over North America / Europe. It took place in the last decade of January and first decade of February 2008.

In addition "seasonal" animations for particular episodes (e.g. autumn 2007) are available.

On January 28th 2008 the weather condition was very permitting to induce gravity waves in the atmosphere on the lee sides of the Eastern Alps and the Dinarides. A cold air outbreak towards the Balkans with a north-north-westerly stream direction can be seen in the AVHRR composites indicated by stationary lens-shaped clouds south of Vienna, over the central part of the Adriatic Sea and offshore the border between Greece and Albania.

Gravity waves play a prominent role in our understanding of atmospheric dynamics through carrying energy and momentum. These phenomena are not well represented in today's climate models which is currently recognized as a significant deficiency.

Daily NRT Cloud Coverage by APOLLO NOAA/AVHRR can be found in the WDC-RSAT data base:
http://wdc.dlr.de/apollo/index.html

Archives directories with all scenes processed so far start here.

The four-dimensional variational analysis method (4D-Var) allows a consistent characterization of the actual atmospheric chemical state. Therefore, calculations using chemical-transport models and the most recent observations of atmospheric constituents are taken into account.

The left image shows ozone and related species in 20km altitude from an analysis based on GOME-2 ozone measurements for December 20th, 2007. An area with reduced ozone values is visible above the Northern Atlantic. As ozone depends both on transport and chemistry information on other species is needed to pin down key processes. CH4 is a rather passive gas in the lower stratosphere. Therefore, its distribution describes to some extent the influence of transport effects on air masses. HNO3 on the other hand is a reservoir gas. It binds ozone depleting NO2. Thus it’s a primer for the stratosphere’s ozone depletion potential.

Daily stratospheric analysis can be found in the WDC-RSAT data base:
http://wdc.dlr.de/data_lib/METOP-A/GOME2/L4/
For example, the daily Northern Hemisphere ozone quicklook is located here:

An aerosol retrieval method called Synergetic Aerosol Retrieval (SYNAER) was transferred from ENVISAT to MetOp instruments: radiometer Advanced Very High Resolution Radiometer (AVHRR) and spectrometer Global Ozone Monitoring Experiment - 2 (GOME-2). The high spatial resolution (2048 x 2048 km frames) of AVHRR was combined with accurate spectral resolution of GOME-2.

The image shows the aerosol optical depth values for two MetOp orbits over Europe and Africa at 21 May 2007. There is large improvement of the pixel coverage in comparison with ENVISAT AATSR/SCIAMACHY measurements (512 x 512 km frames). Cloud pixels in the image were excluded.

For more information on the SYNAER methodology please klick here.

Every year in the southern hemisphere spring, a considerable chemical reduction in ozone is observed in the lower and middle stratosphere. The term "ozone hole" was coined to describe this phenomenon. Its expansion shows a pronounced annual cycle. Its interannual size varies considerably over the years, but the ozone layer shows no signs of overall recovery.
The Antarctic ozone hole has now been observed for the first time by the new GOME-2 instrument (Global Ozone Monitoring Instrument 2). GOME-2 is onboard the EUMETSAT MetOp Earth observation satellite launched on 12 October 2006.
As part of EUMETSAT project AGORA, the GOME-2 ozone data are regularly refined using data assimilation methods at DLR's German Remote Data Sensing Centre. There, the ozone data are combined with models which describe the meteorology, physics and chemistry of the atmosphere. This allows thorough mapping of the ozone layer and a prediction of ozone distribution. These models can also provide additional information not available from the measurements alone. One example is the determination of the chemical depletion rates of ozone.

It was noticeable in mid-September this year that the spread of the ozone hole had undergone a strong reversal (red curve in the illustration). This was caused by unusual meteorological conditions leading to warmer-than-average temperatures in the south polar stratosphere. Therefore it can not be regarded as an indication of the recovery of the ozone layer.

It was exactly 20 years ago that the Montreal Protocol decided as an international environmental protection treaty in favour of banning CFCs. Since then, 191 states have signed the protocol. In the meantime, other classes of substances, so-called partially halogenated CFCs, are being blamed for the reduction in ozone. That is why UNEP (the United Nations Environment Programme) is committed to getting rid of these substances over the next decade.

Further information you can get here
DLR press release
WDC-GOME-2 sensor page
Current antarctic ozone hole size
Animation of the Antarctic ozone vertical column density during September 2007

A hot-spot processor to detect fires during day and night using mid-infrared night-time data from AVHRR has been run to produce maps showing the locations of larger fires. A burning area of about 1000 square meters per AVHRR-pixel (> 1 square kilometer) is sufficient to increase the mid-infrared signal significantly.

The images from August 2007 show the southern part of Greece (Peloponne) where an extreme heat wave strongly influences the beginning of wild fires. The burning fires are indicated in red on the hotspot map overlayed on a color composite of the AVHRR scene.

Beside the hot-spot maps based on AVHRR data, MERIS-RGB images of August 2007, can be downloaded as KMZ files showing the fires on the Peloponnes peninsula.

• August 24, 2007 (right-click to download the files)
• August 30, 2007 (right-click to download the files)

MERIS data are received and processed by DLR-DFD in the frame of the ESA-GEMEL project (ESA-AO 1413).

For more information on fire products at DLR-DFD please send an email to wdc@dlr.de or have a look on the web page of DLR's Center for Satellite Based Crisis Information ZKI.

The Global Ozone Monitoring Experiment-2 (GOME-2) is one of the new-generation European instruments carried on MetOp, which has been jointly established by ESA and EUMETSAT. GOME-2 will continue the long-term monitoring of atmospheric ozone and minor trace gases, such as nitrogen dioxide (NO2), started by GOME on ERS-2 and SCIAMACHY on Envisat. The GOME-2 instrument is a scanning spectrometer that measures the Earth's backscattered radiance and extraterrestrial solar irradiance in the ultraviolet and visible part of the spectrum (240-790 nm). GOME-2 observes four times smaller ground pixels (80 x 40 km) than GOME on ERS-2, and provides a global coverage within about one day.

This image shows tropospheric NO2 columns over Europe (left) and South-East Asia (right) in April 2007, as measured by GOME-2. Nitrogen dioxide is one of the most important contributors to air pollution. Clearly visible in this image are the high tropospheric NO2 concentrations over large urban and industrial areas of Europe and South-East Asia, especially over China. In the last decades, the NO2 pollution in the populated areas of China has increased strongly, mainly because of increased traffic and industrial activities. With the GOME-2 instrument, nitrogen dioxide can be measured worldwide on a daily basis, and at a city-size scale. The NO2 columns are derived from GOME-2 (ir)radiance measurements using the Differential Optical Absorption Spectroscopy (DOAS) method. For the calculation of the tropospheric NO2 column, an Air Mass Factor calculated from an assumed tropospheric NO2 profile is used.
For more information contact wdc@dlr.de.