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News  Dieter Klaes – EPS Programme Scientist
In our continuing series of interviews with key members of the MetOp team, we spoke with EUMETSAT’s Polar System (EPS) Programme Scientist for MetOp-A, Dieter Klaes. What does being the EUMETSAT Polar System (EPS) Programme Scientist for the MetOp-A mission involve?
As EPS Programme Scientist I work with my team within the EPS System Team. My team is responsible for ensuring all scientific aspects of the Programme are taken into account. These tasks included a deep involvement in the development phase of EPS, in particular the development of the data processing, and the test and commissioning. With a team of scientists with specialist knowledge for each of the five processing chains (ATOVS and AVHRR Level 1 and level 2, IASI Level 2, ASCAT Leve1 1, GOME-2 Level 1 and GRAS Level 1), we specified the algorithms and product formats for the processing chains.
The team was also heavily involved in the testing and acceptance of the operational processor. We also provide instrument auxiliary data, like nonlinearity corrections and calibration parameters for several of the instruments. We are now part of the product and science commissioning team, of which I am the deputy team leader. This team involves experts from science, operations, software and instruments.
Since the beginning of the programme we have had science advisory groups and research groups, jointly convened with ESA for GRAS, GOME-2 and ASCAT, and jointly with CNES for IASI. The IASI Sounding Science working Group was also related to a research announcement for IASI, and the group is composed of the Principal Investigators of this Announcement of Opportunity.
The most important involvement of the coming months will be the commissioning phase after the launch in July. In this phase we need to make sure that the users will get all the products we have committed according to specifications. The MetOp series of satellites has come together as a result of international contribution. What role have the different space and industrial agencies played in this process? EPS is Europe’s contribution to a joint European/US operational polar satellite system (Initial Joint Polar System (IJPS). EPS covers the mid-morning (AM) orbit, whereas the U.S. part continues to cover the afternoon (PM) orbit. The cooperation agreement includes the exchange of instruments, exchange of data and coordinated operations, data and services.
EPS is an integrated European effort. EUMETSAT has the overall System responsibility and provides the majority of the funding. EPS was developed in cooperation with EUMETSAT, ESA, CNES and Industry.
The main users will be the national meteorological services of our Member States and co-operating states. One main application in operational meteorology will be the assimilation of the sounder data into numerical weather prediction (NWP) models. Furthermore the MetOp-A data will also contribute to climate monitoring and environmental monitoring. IASI and GOME-2, for instance, can measure atmospheric constituents and hence contribute to atmospheric chemistry. We can monitor the ozone amount in the atmosphere and check whether the implementation of the Montreal protocol will lead to a recovery of the ozone layer, or if global warming will contribute to further ozone depletion.
The operational character of the mission will assure that there will be continuous high quality measurements over at least 14 years, which will observe variability and trends. All data and products will be archived, and we expect a wealth of new and innovative uses of the data in particular from instruments like IASI.
Users will get the EPS/MetOp-A data and products in several ways. Global operational near-real time products will be delivered to users via the EUMETSAT EUMETCast service, i.e. in the same way users get MSG data and products. The delivery delay is 2 hours and 15 minutes after sensing for Level 1 and 3 hours after sensing for Level 2 products. Most products will be delivered in the BUFR format. EUMETCast is a very cost-effective and flexible system that has been developed by EUMETSAT and is currently expanding to carry more products and to reach more users. In addition, global users will receive a subset of the product over the Global telecommunication System (GTS), a network dedicated to meteorological products distribution, which will include a subset of IASI level 1 and ATOVS and IASI Level 2 products.
The measurements are also directly broadcast from the satellite. There is the Advanced HRPT (High Resolution Picture Transmission) service, which contains all mission data and has a bandwidth of three Mbits/sec. There is also the digital LRPT (Low Resolution picture Transmission) service, which contains the full set of ATOVS sounding data (AMSU-A, HIRS/4, MHS) and a set of three JPEG-compressed AVHRR channels. LRPT replaces the former analogue APT (Automatic Picture Transmission) service.
All data and products will be archived in the UMARF (Unified Meteorological Archive and Retrieval Facility) and can be retrieved by users via the archive portal on our web-page. Finally EPS data and products will also be available via the EUMETSAT Advanced Retransmission Service (EARS). This includes ATOVS, AVHRR and ASCAT products from about 10 HRPT stations in partner organisation, which provide nearly total coverage of the Northern Hemisphere with a timeliness of 30 minutes. What is your involvement over the lifetime of the satellite?
Support to the commissioning of the MetOp satellites – commissioning of data and products; Product and processing improvement; Proposal, specification and development of Day-2 products, according to user requirements; Provision of instrument parameters for future MetOp satellite instruments; Support in trouble shooting for product processing; Continuous product validation; Cross-calibration; Support of Re-processing of mission data; Calibration monitoring; Research Announcement of Opportunity; Convene the Science Advisory Groups and the IASI Sounding Science Working Group; and Training and Education.
The MetOp-A instruments fulfil a variety of mission objectives, which are satisfied by the different instruments. Most of the payload on MetOp-A contributes to the operational sounding of temperature and moisture: ATOVS and AVHRR provide continuity and commonality with the NOAA-satellites, IASI provides the required hyper spectral capability and GRAS makes use of radio occultation technology for sounding. The suite of ATOVS instruments and the IASI instrument are used in a synergistic way. The AVHRR/3 imager supports them. AMSU-A provides as a microwave instrument the (nearly) all-weather capability. The GOME-2 and IASI instruments have the capability to monitor the ozone total column and profiles and the components related to the ozone chemistry in the atmosphere. The GOME-2 instrument on MetOp-A is a result of the experience gained over a number of years of operations and data analysis with the GOME-1 instrument on ERS-2. The products derived from GOME-2 will include the trace gases involved in the ozone chemistry as well as ozone total column amount and ozone profiles.
Additionally, it is expected that aerosol properties, as Absorbing Aerosol Indication, Aerosol Optical Depth and Aerosol Type (desert dust, smoke and volcanic ash) can be derived. Finally, clear sky and cloudy UV fields are expected to be derived. It is also anticipated that the retrieval of the trace gases like ozone, N2O, CO and CH4 is possible with IASI.
The Advanced Wind Scatterometer (ASCAT) will provide wind speed and direction using a model, which relates them to the normalised radar backscattering cross section. Further potential of ASCAT lies in the measurement of sea ice boundaries and sea ice concentration and type. Land surface applications are supported with AVHRR and this continues a service available already for two decades. These include Normalized Differential Vegetation Index, desertification monitoring, fire detection and snow cover monitoring.
Numerous scatterometer applications over land have been shown using scatterometer data from the ERS satellites. New methods for the retrieval of soil moisture will be exploited operationally in the EPS Ground Segment to provide information for NWP in near-real time. Further applications, which ASCAT may support, are monitoring of snow and ice coverage and vegetation type and coverage.
Temperature and humidity are two important atmospheric parameters and are not easy to measure. The instruments compliment each other and will be used in synergy. Infrared Soundings, for example, will not be able to penetrate through clouds. By combining these data with those of microwave instruments, which are nearly not affected by clouds, temperature and humidity soundings can be provided also in partly cloudy and cloudy areas. One can, by using the microwave data, correct for the cloud contamination of a sounding pixel. Some parametres cannot be derived by IR instruments (for example cloud liquid water content and total liquid water content), but can be with microwave instruments. GRAS makes use of the GPS (Global Positioning System) constellation of 24 satellites distributed in six orbital planes around the globe.
The GRAS instrument in near polar orbit at 824 km will observe over 500 occultations per day distributed quite uniformly over the globe. Assimilation of GRAS data into NWP is expected to provide improvements of the representation of the polar stratosphere. As GRAS is a self-calibrating instrument, it will be useful for generating a climate data record.
Absolutely. We have the innovative IASI instrument, which will provide sounding data at hyper spectral resolution and enable temperature and moisture soundings with an unprecedented accuracy. We have also instruments, which were embarked on research missions and which are now flown on an operational mission: ASCAT and GOME-2. The predecessors of these instruments were flown on ERS satellites, but not on the NOAA satellites. Finally we have the GRAS instrument, which introduces the radio occultation technique with GPS signals into an operational meteorological mission for the first time. What have you enjoyed most about working on the MetOp series of satellites so far? Working on a set of innovative and demanding instruments was certainly one extremely exciting part of my work on EPS/MetOp. To deal with the development of algorithms to exploit the data of instruments like IASI, GOME, ASCAT and GRAS was a challenge and also fun – and a lot to learn.
The other fun aspect, and where I also learnt a lot, was to build the science team and to work with extremely good and competent people in a very demanding environment, both schedule wise and also in terms of tasks to fulfil. I have to pay tribute to the excellent team without which all the achievements would not have been possible.
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