# Campaign logbook
```{admonition}
Contact
Cyril Crevoisier, LMD
Véronique Piou, CNES
```
(20251014)=
## Tuesday 14th October
A challenging day for the team! A fault was detected on the ATR42. An investigation was immediately launched and the diagnosis was made at the end of the afternoon: the pitch trim was faulty. The parts needed for the repair were ordered and were due to be delivered first thing the next morning.
**Investigating the cause of the ATR42 failure © C. Crevoisier, 2025**
The ATR42 was therefore grounded for the entire day and the first flight to Madrid, in coordination with the other teams, was cancelled. This was a serious blow to morale, but the team remained motivated for the days ahead.
A big thank you to the SAFIRE team for their excellent responsiveness in identifying the fault and taking the necessary steps to repair the aircraft, but also for enabling the instruments to be powered by an external power supply, so that they could be heated while the fault was being repaired.
Meanwhile, Gerfaut and the ground-based team in Madrid continued their measurements. Multiple legs were flown close to South-Eastern sources, with the addition of 3 profiles. Sources includes 2 cement production sites and one thermal power plant. A few signals were captured despite very small wind.
**Gerfaut flight map (top) for CO2 and CH4 and evolution of their mixing ratios along the flight, with 3 profiles between 700 and 3100 ft.**
Everyone is eagerly awaiting the first joint flight to Madrid!
(20251013)=
## Monday 13th October
A new early start for today in Francazal, with hangar opened at 4:45 to start heating CHARM-F and Picarro instruments. ATR42 was taken out at 6:45 for refueling and crew boarding at 7:00. Take-off happened at 8:00 in light fog.
**SAFIRE ATR42 going out the hangar at Francazal airport and waiting while the sun rises © C. Crevoisier 2025**
Flight to Bilbao was the occasion to enjoy the Basque coast under a steady sun… that did not last while arriving at Bilbao. Decision was rapidly taken to discard the envisioned southern legs where clouds were persistent. The first legs over the oceans and the harbour went well.
**Views from the ATR42 over the French Basque coast (left), over Bilbao and the LNG terminal (middle) and over the mountains above Bilbao (right) © C. Pietras and E. Wolkiewiez, 2025**
But clouds decided to keep moving in. The aircraft found itself stuck between two layers of clouds, with light ice crystals even forming on the windows. Unfortunately, changing altitude from FL170 to FL160 did not restore good measurement conditions for the lidars, whose signal was too weak to provide relevant measurements.
After an hour on site, the decision was therefore made to leave the area and return to Francazal early. On the return journey, the ATR42 was able to fly over Lacq, but once again the clouds played their part and a low cloud formed just above the industrial site.
**Two layers of clouds and even crystal droplets call a shift in the flight legs above Bilbao © E. Wolkiewiez and C. Pietras, 2025**
Meanwhile in Madrid, the weather conditions improved and Gerfaut was able to take-off and perform a new survey.
**Views from Gerfaut Dynamic WT9 flying at 3 km around Madrid ©P. Laulhere, 2025**
However, the very weak wind above the city prevented the formation of a plume and created a kind of stationary blob above the city. A straight path cutting through this blob was therefore chosen. Measurements taken by the Picarro instrument on board the Dynamic WT9 revealed a very clear increase in **CO2 (~5ppm)** and **CH4 (~70ppb)** above the city.
**CO2 (left) and CH4 (right) mixing ratios measured by the Picarro onboard Gerfaut Dynamic WT9 over Madrid.**
In addition to providing very interested information on Madrid anthropogenic emissions, this result confirms that this type of trajectory is preferable for the ATR42 in the event of very low winds in order to test CHARM-F's ability to capture such a signal. To be tested in the coming days...
(20251012)=
## Sunday 12th October
Today was a day-off for the measurements… but the computers were on to analyze the data. Time to reflect on this past week.
As shown on the map, in the air, were already performed:
- 4 flights of SAFIRE ATR42: 2 to Fos-sur-mer, one to Bilbao and one to Barcelona, the two last ones in coordination with Gerfaut Dynamic WT9.
- 5 flights of Gerfaut Dynamic WT9: 3 in Madrid and the 2 coordinated with the ATR42 in Bilbao and Madrid.
**SAFIRE ATR42 (red) and Gerfaut DynamicWT9 (yellow) flights over the first week of AB2CD**
And ground-based EM27/SUN spectrometers of AEMET delivered a continuous times series of XCO2, XCH4 and XCO over the week. With favourable wind conditions, clear gas enhancement were observed at the sites. This is particularly well seen on the 4th and 7th of October.
**Time series of wind speed, XCO2, XCH4, XCO and XH2O as measured by the 2 EM27/SUN spectrometers deployed at Madrid during the AB2CD campaign.**
The time spirit is high and everybody is eagerly waiting for next week flights to Madrid… if weather allows!
(20251011)=
## Saturday 11th October
An early start today for the team! SAFIRE opened at 5:30 in the morning to power up the ATR42 and allow for CHARM-F and Picarro heating phase. After last checking and some coffee with croissants, the go was received from Spanish ATC. Take-off happened at 8:00, for a 4-hour flight back and forth to Barcelona.
**SAFIRE ATR42 at Francazal airport in the early morning © S. Wolff and C. Crevoisier, 2025**
On the way, amazing views over the Pyrenees mountains… while enjoying some sweets from SAFIRE crew. :smiley
**The Pyrenees seen from SAFIRE ATR42 © S. Wolff and C. Crevoisier, 2025**
The strong wind was blowing along the coast line, yielding a well-established plume of CO2 and CH4. Today targets included: Barcelona Power Station, TERSA incineration plant, Holcim cement plant, Almacen steel factory, Molins cement plant.
Several spikes of XCH4 were seen by CHARM-F in the Southern corner of the box flight, while a constant layer of aerosol was detected over all the area by LiVe at 1.5km.
After 2 hours of flight of Barcelona and a perfect coordination between the pilots and Barcelona AATC, the ATR42 went North for a 45 trip back to Francazal airport.
**Barcelona city and the LNG terminal at the harbour seen from SAFIRE ATR42 © C. Crevoisier and S. Wolff, 2025**
Meanwhile, Gerfaut Dynamic WT9 took-off from Madrid at 8:56 to land at Barcelona at 12:11, refuel and then took-off again for a 3-hour flight. Two vertical profiles were measured at the beginning and the end of the flight. The rest of the flight was devoted to several parallel legs South-West of the ATR42 track in order to catch the CO2/CH4 plume.
All in all, a great day that marks the halfway point of the campaign.
(20251010)=
## Friday 10th October
Two targets have been studied today: Fos-sur-mer and Madrid.
**Flight plans for Gerfaut Dynamic WT9 and SAFIRE ATR42 for Friday 10 October, designed to catch the plume exiting from either Madrid or Fos-sur-mer**
The ATR42 flew to Fos-sur-mer, repeating a similar pattern as on Monday 6th, but slightly tilted to take into account the wind direction. The flight took 4 hours with 2 hours on site between 15:15-17:15 local time. In addition, a missed approach at Montpellier airport was granted by ATC, in replacement of a profile at a fixed location that was not possible due to military activities. All instruments performed well.
The Dynamic WT9 flew in Madrid with a pattern specifically designed to catch the exiting plume from the city, from 13:00-16:00. In addition, a profile 0-3,500 ft was performed in the Southern part of the flight.
(20251009)=
## Thursday 9th October
Due to bad weather at all site, no flight was planned for today. But the perspectives of flying over Madrid the next day was brightening the day. Analysis of weather forecast, flight conditions, plume simulation, feedback from previous days kept the team quite busy!
Analysis of EM27/SUN measurements performed the previous days at the sites in Madrid offered some insight on the typical signals expected at these locations. When the wind was blowing in the good direction, from the city towards the spectrometer locations, a clear enhancement of XCH4 was captured (about 60 ppb, well seen between 11:00 and 13:00 UTC (13:00-15:00 local time). A plume well seen on the CH4 mixing ratio measured by the Picarro onboard Gerfaut Dynamic WT9. This type of signal should be easily captured by the active instruments onboard the ATR42.
**Analysis of Madrid measurements over the first days of the campaign. Left: CH4 mixing ratio measured by the Picarro onboard Dynamic WT9, with a clear enhancement South West of Madrid along the wond direction. Middel and right: time series of the CH4 columns measured by the 2 EM27/SUNs showing, for the same day as the aircraft measurement enhancement of 60 ppb at both sites.**
Unfortunately, some bad news arrived late in the morning, resulting in no fewer than three briefing meetings being held: a flight restriction over Madrid was received, allowing for only one of the three aircrafts to fly at a time. Since Vulcanair P68 carrying GHGSat-AV was already granted permission to fly on Friday morning as part as another ESA project, and that the weather forecast was bad for the rest of the day, it was decided to cancel the preparation for a coordinated flight over Madrid.
Next day will thus be devoted to flying over Fos-sur-mer, thanks to the excellent responsiveness offered by the French CER.
(20251008)=
## Wednesday 8th October
Today, it was time for the first ATR42 flight to Spain and the first coordinated flight of the campaign with Gerfaut Dynamic WT9. Their target: Bilbao. According to HYSPLIT simulations and weather forecast, an inland plume was expected with winds blowing from the ocean. Accordingly, ATR42 flight plan consisted of legs perpendicular to the winds. The position of each leg was chosen to maximize the chances to detect emissions from identified sources. Those include:
**ATR42 flight plan (orange legs) over the plume simulation from the HYSPLIT model, chosen to detect emissions from known sources (red points)**
Unfortunately for the team, the LNG terminal at Bilbao harbour seemed to not be operating.
All instruments performed nominally. LiVe signal was been far better over Spain than during the previous flights over France, and lower again after crossing the border on the way back to Toulouse, stemming from different aerosol loads over the two countries.
-->
**Coordinated flight between SAFIRE ATR42 and Gerfaut Dynamic WT9 as seen on [Flightradar24](https://www.flightradar24.com)**
A kudo to the Gerfaut team who had to dispatch a special team from Madrid to Bilbao to allow for refuelling and powering the Dynamic WT9 after its flight in the morning from Madrid.
**The Gerfaut team around its Dynamic WT9 ©Gerfaut, 2025**
And to end even better, the green light was given today by ENAIRE for flight over Madrid and Barcelona, in addition to Bilbao. The 4 targets of AB2CD can now be targeted, when weather allows
(20251007)=
## Tuesday 7th October
Today, the weather was fair, but the wind too low at both Bilbao or Fos-sur-mer. SAFIRE ATR42 stayed grounded, leaving the opportunity to analyse the first data gathered the previous days. Time also to plan for the rest of the week, with everyone eagerly awaiting a feedback from the Spanish authorities concerning clearance to fly over Madrid and Barcelona.
Over Madrid, ground-based EM27/SUN spectrometers continued their measurements under a fine weather.
**A view of ATR42 on board instruments and crew preparation © C. Crevoisier, 2025**
**Checking of the ATR42 engines at Francazal airport © C. Crevoisier, 2025**
(20251006)=
## Monday 6th October
The first scientific flights of AB2CD took place today. At 13:30 LT, SAFIRE ATR42 took-off for a 2 hour flight targeting industrial emissions over the Gulf of Fos-sur-mer. The raster pattern was flown at FL170 (5 000m), with each leg flown twice. Both lidars (CHARM-F and LiVe) performed well with a lot of signals captured in a well-defined channel of strong wind of about 10 m/s.
**The ATR42 (blue) flying the selected flight plan (green) as seen on the Planet screen over the Gulf of Fos-sur-mer in order to catch the expected gas plume as simulated by HYSPLIT… at the overpassing time of Sentinel-5P (yellow track)**
**The gulf of Fos-sur-mer, industrial site and tanks arrival © V. Douet, 2025**
The return journey was used to fly at a lower altitude in order to check LiVe performances and SNR closer to the ground. First analysis revealed quite a clean atmosphere, potentially stemming from the heavy rain from the previous days.
**Views around Fos-sur-mer © V. Douet, 2025**
A very succesful first scientific flight of the ATR-42 ... that lead to the first team picture of a happy crew!
**The ATR42 team in front of the research aircraft after landing from the first scientific flight. Team includes SAFIRE, DLR, ONERA and LMD.**
Meanwhile in Madrid, Gerfaut Dynamic WT9 performed its first test flight in the area. A great opportunity to discover the area and define the future flight plans. A clear methane plume was observed South-West of Madrid.
**Gerfaut Dynamic WT9 taking off from Madrid airport with a Picarro 2301 onboard, and views from the cockpit © G. Gavin, 2025**
After a cloudy morning, the 2 EM27/SUN installed at UCM and ECHEGARAY measured total columns of gases in the afternoon.
(20251006)=
## Friday 3th - Monday 6th October
A final test flight carried out on October 6th between 10:00 and 11:00 has confirmed that LiVe is working nominally! It is thus a go for the ATR42!
On Saturday 4th, the joined AEMET/ TRAGSATEC team installed both EM27/SUN at UCM and ECHEGARAY. Measurements started under a beautiful sky.
After a successful installation of Picarro instrument on board Gerfaut Dynamic WT9 by the AEROLAB team, the light aircraft flew to Madrid on Sunday 5th.
Congratulations to all the teams for a successful preparation of the campaign!
(20251002)=
## Thursday 2nd October
A test flight of SAFIRE ATR42 was performed in the South of France to assess the readiness of all instruments onboard. The team took this opportunity to fly under the Chinese DaQi-1 satellite, which carries the ACDL CO2 lidar, allowing for a direct comparison between the spaceborne and airborne lidars!
CHARM-F and passive instruments performed well, but too low a SNR was obtained with LiVe. Tests are planned for the following days to ready the lidar before the first scientific flight on Monday.
(campaign:prepa)=
## Campaign preparation
DLR and ONERA teams arrived at SAFIRE premises on September 26th to start the integration of both lidar instruments onboard the ATR42 aircraft. Initial scientific discussion for flight planning happened between on-line meetings with the other teams.