The primary objective of the European eXport of Precursors and Ozone by long-Range Transport (EXPORT) project is to characterise and quantify the photochemical air pollution both forming over Europe and being exported eastwards from Europe. The data held at BADC was collected during a co-ordinated 3 aircraft flying campaign in August 2000 based at Oberpfaffenhofen in Southern Germany. Measurements were made of many photochemical parameters including ozone, its precursors, other oxidants and both gas phase and particulate tracers in the air over Europe and that being transported eastwards out of Europe. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A772 for the EXPORT project. The flight was from Oberpfaffenhofen to Romania and back. After an uneventful pre-flight the aircraft departed just under five minutes behind schedule. There were a few tense moments when it was realised that the GPU was in danger of running out of fuel. This was replaced but it is obvious that procedures need to be put in place to eliminate this risk! Diplomatic problems were also encountered with the Romanian authorities. The DLR and MRF clearances appeared to have been muddled and at 10:56 GMT we were refused entry to the Romanian air space. MRF base sorted the problem, receiving a signal authorising clearance at 11:17 GMT. Fortunately, the intended operating area had shifted westward and a suitable region was located in eastern Hungary. The mission scientists were happy with the polluted air, which was sampled. At the southern extent large convective cells were encountered but conditions were more stable to the North. No major instrument problems were noted during the flight. Overall the flight was reasonably successful.

The primary objective of the European eXport of Precursors and Ozone by long-Range Transport (EXPORT) project is to characterise and quantify the photochemical air pollution both forming over Europe and being exported eastwards from Europe. The data held at BADC was collected during a co-ordinated 3 aircraft flying campaign in August 2000 based at Oberpfaffenhofen in Southern Germany. Measurements were made of many photochemical parameters including ozone, its precursors, other oxidants and both gas phase and particulate tracers in the air over Europe and that being transported eastwards out of Europe. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A771 for the EXPORT project. The flight was from Boscombe to Oberpfaffenhofen. The main aim of the flight was to transit from Boscombe Down to Oberpfaffenhofen. However, it was also the first, and only, opportunity to test the recently refitted instruments. In particular, it had been requested that the peroxide instrument should be tested at altitude, in order to check for leaks. The flight did not get of to a good start, as power was lost, due to the GPU running out of fuel. A faulty oxygen regulator was then noted, which had to be repaired before take-off. We delayed slightly and a full warm-up of the NOxy was not achievable but the operator was happy to go on the basis that it was a test flight. The flight showed up a few problems: the peroxide lost flow on ascent to FL190; the CN counter kept switching off; the Leeds GC (ORAC) was noisy and there were spikes on the JO1D and jNO2 lower radiometers. All in all it was a useful test; giving confidence in most of the instruments.

The primary objective of the European eXport of Precursors and Ozone by long-Range Transport (EXPORT) project is to characterise and quantify the photochemical air pollution both forming over Europe and being exported eastwards from Europe. The data held at BADC was collected during a co-ordinated 3 aircraft flying campaign in August 2000 based at Oberpfaffenhofen in Southern Germany. Measurements were made of many photochemical parameters including ozone, its precursors, other oxidants and both gas phase and particulate tracers in the air over Europe and that being transported eastwards out of Europe. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A773 for the EXPORT project. The flight was over southern and eastern Germany. Transport of Pollution through a Warm Conveyor Belt From Oberpfaffenhofen the route was first to the far SW of Germany. However, in order to avoid the worst of the cloud (for the NOxy calibration) some retracing of our steps was required. Once at the south western waypoint, the plan was then to cross the front in a square wave pattern, travelling in a north eastern direction and increasing in altitude between runs. This was carried out successfully. We remained within the belt of cloud for much of the flight. The flight appears to have been rather successful. Certainly transport of CO, HCHO, NOx and NOy (including PAN), out of the boundary layer, was very clear. The highest CO mixing ratios (ca. 150 ppb) were found at around 10:40 during a run at FL100. PAN at this time was estimated to be nearly 1 ppb. The following runs at FL120 and FL140 also showed elevated CO etc but CO maxima decreased with altitude. Whether all of the transport was due to the conveyor or if some of it was due to convection remains to be seen. The mixing ratio of ozone throughout the cloudy region was fairly constant (around 50 - 60 ppb); indicating that there had been limited photochemical processing. Once clear of the northern edge of the cloud, the aircrew carried out a 50ft approach to an airfield in Leipzig. This allowed sampling of the boundary layer in the region and was quite a contrast to the rest of the flight. High SO2 readings (ca. 2 ppb) and high NOx readings (TECO NOx ca. 18 ppb) were observed but it should be noted that these were not concurrent: the maximum in NOx following that in SO2 by ca. 5 mins. During this time period the CN was off scale (the CO peaked at around 200 ppb and ozone was reduced to around 30ppb). The high concentrations of primary pollutants were unsurprising given the observation of large industrial chimneys etc in the area. There were a fair number of instrument problems. The lower jNO2 and jO1D radiometers were found to go to full-scale for short periods. The HORACE TAS and TAT were clearly erroneous for a period of around half-an-hour starting at around 9:45 GMT. The flow in the PSAP instrument could not be maintained and missing 'O' rings needed replacing at the beginning of the flight. The FWVS was also found to drop down to -70.5°C fairly regularly. Early problems with the CO instrument (blown fuse) were soon rectified. All other chemistry equipment appeared to work well, despite the very wet conditions. The Met Office midday analysis showed the surface cold front stretching from Northern France to the triple point at the Baltic Sea. The path across Germany was fairly closely matched by the flight plan.

The African Easterly Jet (AEJ) is part of a climatic system which is of critical importance to African and global weather and climate, but is poorly observed and not well represented in model analyses. For the JET2000 project the Met Office Met Research flight (MRF) aircraft performed four flights, involving transects along and across the jet and the baroclinic zone, to make observations of unprecedented resolution for this part of the world. 110 dropsondes were dropped along the fight path. The Meteorological Research Flight (MRF) was a Met Office facility, which flew a well-instrumented C-130 Hercules aircraft for atmospheric research purposes. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A780 for the JET2000 project. The flight was located over Niamey, Niger.

The African Easterly Jet (AEJ) is part of a climatic system which is of critical importance to African and global weather and climate, but is poorly observed and not well represented in model analyses. For the JET2000 project the Met Office Met Research flight (MRF) aircraft performed four flights, involving transects along and across the jet and the baroclinic zone, to make observations of unprecedented resolution for this part of the world. 110 dropsondes were dropped along the fight path. The Meteorological Research Flight (MRF) was a Met Office facility, which flew a well-instrumented C-130 Hercules aircraft for atmospheric research purposes. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A782 for the JET2000 project. The flight was located over Cape Verde and Niamey, Niger.

The primary objective of the European eXport of Precursors and Ozone by long-Range Transport (EXPORT) project is to characterise and quantify the photochemical air pollution both forming over Europe and being exported eastwards from Europe. The data held at BADC was collected during a co-ordinated 3 aircraft flying campaign in August 2000 based at Oberpfaffenhofen in Southern Germany. Measurements were made of many photochemical parameters including ozone, its precursors, other oxidants and both gas phase and particulate tracers in the air over Europe and that being transported eastwards out of Europe. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A775 for the EXPORT project. The flight was over Germany, Austria, Czech and Slovak Reps, and Poland. Study of PBL Air over Czech Republic and southern Poland contrasted with Uplifted (N. American) air at ca. 25,000ft The aim of the experiment was to observe two areas of polluted air, as forecast by RDF trajectory forecasts and the NILU model. The first area was forecast to be over the Czech Republic / southern Poland at low levels and the second was forecast to be over southern Poland / Germany at higher altitudes (ca. 26,000 to 29,000ft. Both the Mystere and Falcon aircraft only planned to sample the higher altitude polluted layer. The results from the Mystere were planned to feed back to the C-130, after sampling the low level air. Indeed communications from the Mystere were passed to the C-130 but probably made little difference to the eventual plan. The flight was very interesting. The main science started with a profile into an airfield at Ostrava, Czech Republic. Bottles were filled during the descent into the airfield. These should show 'chemical age' difference above and below the boundary layer. Below the inversion at around FL045, a rather heavily polluted boundary layer was sampled in the Czech Republic / southern Poland. Several runs were carried out in this air, mostly at an altitude of approximately 3,000ft above ground. The flight area was mostly very heavily polluted, with several factory chimneys and at least one power station that was passed several times. Once above a more rural area the levels of primary pollutants dropped significantly, possibly indicating that a significant fraction of the primary pollutant concentrations were due to the local sources. The aircraft remained in the PBL for quite some time. This was partly due to the requests of the mission scientists but also because of having to wait to go into Polish airspace. The second part of the flight was at higher level, between ca. 26,000 and 29,000ft, in order to sample uplifted air forecast to be of N. American origin. The air was certainly rich in CO (up to around 100ppb) but interestingly the ozone was anti-correlated with the CO. It is possible that the air had been uplifted in convection, in which case the ozone concentration might be anti-correlated with the CO, if there has been insufficient time for photochemical processing. Alternatively, boundary layer air (from either N. America or Europe) may have mixed with dry, ozone-rich UTLS air. Most instruments performed well, the exception being the PSAP, which was very noisy. The NOxy worked well but reported loss of flow into the NOy1 inlet (NOy minus HNO3), above ca. FL240. Meteorology The surface chart showed a weak ridge of high pressure over central Europe. The midday analysis showed a frontal feature stretching from the North Sea, across NE Germany and into Southern Poland. Some troughing of the upper air.

The primary objective of the European eXport of Precursors and Ozone by long-Range Transport (EXPORT) project is to characterise and quantify the photochemical air pollution both forming over Europe and being exported eastwards from Europe. The data held at BADC was collected during a co-ordinated 3 aircraft flying campaign in August 2000 based at Oberpfaffenhofen in Southern Germany. Measurements were made of many photochemical parameters including ozone, its precursors, other oxidants and both gas phase and particulate tracers in the air over Europe and that being transported eastwards out of Europe. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A776 for the EXPORT project. The flight was over Germany, Austria, Czech and Slovak Reps, and Poland.

The primary objective of the European eXport of Precursors and Ozone by long-Range Transport (EXPORT) project is to characterise and quantify the photochemical air pollution both forming over Europe and being exported eastwards from Europe. The data held at BADC was collected during a co-ordinated 3 aircraft flying campaign in August 2000 based at Oberpfaffenhofen in Southern Germany. Measurements were made of many photochemical parameters including ozone, its precursors, other oxidants and both gas phase and particulate tracers in the air over Europe and that being transported eastwards out of Europe. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A774 for the EXPORT project. The flight was overGermany, Austria, Czech and Slovak Reps, and Poland. The sortie was flown without any major problems. The mission scientists opted to do more levels in Nitra Slovakia, with level runs at FL70, 90, 130, 150 and 200. There was some confusion with calibrations and zeros, which had not been integrated into the sortie brief. This resulted in effectively extending each run from 10 to 15 minutes. The Falcon was operating in the area at the same time. At one point they flew underneath us at FL90, while we were at FL120 flying eastbound. We then transited north to Poland, via the Czech Republic. An additional 50' approach to Pardevice airport was added into the sortie before the final transit back to Oberpfaffenhofen. Heavy cloud and precipitation was encountered on the return transit to a very wet Oberpfaffenhofen.

The African Easterly Jet (AEJ) is part of a climatic system which is of critical importance to African and global weather and climate, but is poorly observed and not well represented in model analyses. For the JET2000 project the Met Office Met Research flight (MRF) aircraft performed four flights, involving transects along and across the jet and the baroclinic zone, to make observations of unprecedented resolution for this part of the world. 110 dropsondes were dropped along the fight path. The Meteorological Research Flight (MRF) was a Met Office facility, which flew a well-instrumented C-130 Hercules aircraft for atmospheric research purposes. The flight was located over Cape Verde and Niamey, Niger. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A779 for the JET2000 project.

The African Easterly Jet (AEJ) is part of a climatic system which is of critical importance to African and global weather and climate, but is poorly observed and not well represented in model analyses. For the JET2000 project the Met Office Met Research flight (MRF) aircraft performed four flights, involving transects along and across the jet and the baroclinic zone, to make observations of unprecedented resolution for this part of the world. 110 dropsondes were dropped along the fight path. The Meteorological Research Flight (MRF) was a Met Office facility, which flew a well-instrumented C-130 Hercules aircraft for atmospheric research purposes. This dataset contains airborne atmospheric and chemistry measurements taken on board the Met Office C-130 Hercules aircraft flight A781 for the JET2000 project. The flight was located over Niamey, Niger.