Index: For_developers/Sphinx/source/ecmwf_data.rst
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--- For_developers/Sphinx/source/ecmwf_data.rst	(revision ba9923062b4af98cbdd20c4101c305766fc728f5)
+++ For_developers/Sphinx/source/ecmwf_data.rst	(revision f20342a474e36967cf41b6e992ab0fd6992624c4)
@@ -7,27 +7,27 @@
 
 
-The European Centre for Medium-Range Weather Forecasts (`ECMWF`_), based in Reading, UK, is an independent intergovernmental organisation supported by 34 states. It is both a research institute and a full time operational service. It produces global numerical weather predictions and some other data which is fully available to the national meteorological services in the `Member States`_, Co-operating States and the broader community. Especially, the published re-analysis datasets are made available to the public with some limits in specific datasets.
+The European Centre for Medium-Range Weather Forecasts (`ECMWF`_), based in Reading, UK, is an independent intergovernmental organisation supported by 34 states. It is both a research institute and a 24 h / 7 d operational service. It produces global numerical weather predictions and some other data which are fully available to the national meteorological services in the `Member States`_, Co-operating States, and to some extend to the broader community. Specifically, re-analysis data sets are made available to the public, however, with some limitations for specific data sets.
 
-The amount and structure of the available data from ECMWF is very complex. The operational data changes regularly in time and spatial resolution, physics and parameter. This has to be taken into account carefully and each user has to investigate his dataset of interest carefully before selecting and retrieving it with ``flex_extract``.
-The re-analysis datasets are consistent in all the above mentioned topics over their whole period but they have each their own specialities which makes treatment with ``flex_extract`` special in some way. For example, they have different starting times for their forecasts or different parameter availability. They also have differences in time and spatial resolution and most importantly for ``flex_extract`` they are different in the way of providing the vertical coordinate. 
+There is vast amount and of data with a complex structure available from ECMWF. The operational data undergo changes with respect to temporal and spatial resolution, model physics and parameters available. This has to be taken into account carefully and every user should have a clear idea of the data set intended to be used before retrieving it with ``flex_extract``.
+Each re-analysis data set is homogeneous with respect to resolution etc., but the different re-analyses alll have specific properties which requires a corresponding treatment with ``flex_extract``. For example, the starting times of the forecasts may be different, or the availability of parameters (model output variables) may vary. They also differ in their temporal and spatial resolution, and - most importantly for ``flex_extract`` - there are differences in the way how the vertical wind component may be accessed. 
 
-There is much to learn from ECMWF and their datasets and data handling and this might be confusing at first. We therefore collected the most important information for ``flex_extract`` users. In the following sections the user can use them to get to know enough to understand how ``flex_extract`` is best used and to select the parameters of the ``CONTROL`` files. 
+As there is much to learn about ECMWF and its data sets and data handling, it might be confusing at first. Therefore, we have here collected the information which is most important for ``flex_extract`` users. Study the following sections to learn how ``flex_extract`` is best used, and to select the right parameters in the ``CONTROL`` files. 
 
 
 :doc:`Ecmwf/access`
-    Description of available access methods to the ECMWF data.
+    Description of available  methods to access the ECMWF data.
 
 :doc:`Ecmwf/msdata`
-    Information about available data and parameters for member state users which can be retrieved with ``flex_extract``
+    Information about available data and parameters for member-state users which can be retrieved with ``flex_extract``
 
 :doc:`Ecmwf/pubdata`
-    Information about available data and parameters for the public datasets which can be retrieved with ``flex_extract``
+    Information about available data and parameters for the public data sets which can be retrieved with ``flex_extract``
 
 :doc:`Ecmwf/hintsecmwf`
-    Collection of hints to best find information to define the dataset for retrievement and
-    to define the ``CONTROL`` files.
+    Collection of hints to best find information to define the data set for retrieval, and
+    to define the content of the ``CONTROL`` files.
 
 :doc:`Ecmwf/ec-links`
-    Link collection for additional and useful information as well as references to specific dataset publications.
+    Link collection for additional and useful information as well as references to publications on specific data sets.
 
 
