From Polstracc
The POLSTRACC Summer Meeting has taken place in Klingenmünster, and latest results on dynamic processes, polar stratospheric clouds, cirrus clouds and chemical processes in the Arctic lowermost stratosphere were presented. The POLSTRACC special issue in the journals ACP and AMT is now open for submissions.
Summer Meeting

The POLSTRACC Summer Meeting is scheduled for 05.-06. July 2017. We are looking forward to discuss the latest results from the POLSTRACC/GW-LCYCLE/SALSA data.

After an exciting Science Workshop in Klingenmünster, the scientific evaluation of the POLSTRACC/GW-LCYCLE/SALSA data proceeds. The next meeting is planned for summer 2017 at the same location.

After the POLSTRACC/GW-LCYCLE/SALSA Campaign was concluded successfully in March 2016, the first POLSTRACC Science Workshop is scheduled for 09.-10. November 2016 in Klingenmünster, Germany.

With the dismounting of the payload completed, this now finally concludes the POLSTRACC/GW-LCYCLE/SALSA campaign. We would like to thank all who have contributed to make this campaign a great success! With the campaign itself completed, the focus of the work will now shift towards the scientific analysis of the data.

The HALO Kuratorium (supervisory board) visited on Monday, 21 March the POLSTRACC/GW-LCYCLE/SALSA campaign in Oberpfaffenhofen. With the two proud coordinators Björn-Martin Sinnhuber and Hermann Oelhaf on the ladder. (Photo: DLR:
HALO Kuratorium

The final HALO science flight of the joint POLSTRACC/GW-LCYCLE/SALSA campaign was successfully completed today. HALO science flight PGS_21 went north again to probe the same air masses that have been observed during PGS_19 five days later to investigate transport and mixing of polar vortex air during the stratospheric final warming. A refueling stop was included to reach as high as possible. Because the foreseen airports for refueling in central Scandinavia had adverse surface conditions, we changed plans on short notice and made the refueling stop in Kiruna. (The photo of the HALO start in Oberpfaffenhofen was in fact taken the day before during the BAHAMAS calibration flight.)
HALO start

HALO science flight PGS_20 was successfully completed today. The flight was particularly tailored to meet the SALSA objectives, with a southernmost latitude of 25°N. A refueling stop in Faro was included on the way back.

With a detour via Greenland and a fuel stop in Kangerlussuaq to probe polar vortex air masses as part of science flight PGS_19, HALO now arrived in Oberpfaffenhofen. We plan for one or two more science flights in the coming days to investigate transport and mixing of polar air masses into mid latitudes and to meet the SALSA objectives.
HALO return

Gravity waves over northern Greenland were the focus of HALO science flight PGS_18. The turbulence associated with the strong gravity waves was well noticed on board. (Photo by Björn-Martin Sinnhuber: Gravity waves seen over Greenland.)
Gravity waves over Greenland

HALO took off for science flight PGS_17 and is now on its way to Greenland.

(Photo by Andreas Minikin.) PS: Meanwhile HALO savely returned and the flight was very successful, as far as we can tell this at the moment. A refueling stop was performed in Kangerlussuaq, Greenland.

Take off for PGS_17

HALO savely returned from the successful science flight PGS_16 that went to the southern tip of Greenland to investigate gravity waves and to probe trace gas structures south of Iceland. A refueling stop was performed in Keflavik, Iceland. On-board operators (from left to right): Jens Krause, Florian Obersteiner, Thomas Gulde, Stefan Kaufmann. Not shown: Mathieu Quatrevalet. Photo: Jens Krause.
On board HALO during PGS_16

Gavity waves and a the tropopause structure around a small polar low off the coast of Norway were the focus of HALO science flight PGS_15 that was successfully completed on 29.02.2016.

The second Kiruna phase of the POLSTRACC mission started with HALO science flight PGS_14. During this 9h40min flight we probed aged polar vortex air masses west of Greenland in the Canadian Arctic (photo by Jens Krause). Polar stratospheric clouds were observed over the Norwegian Sea.
PGS_14 over Greenland

HALO has just returned from science flight PGS_13 that went up to 87°N and included a hexagon pattern around Spitsbergen to probe gravity waves. This concludes the first Kiruna phase of the POLSTRACC/GW-LCYCLE/SALSA mission.

With PGS_12 today we finished successfully another 9 hrs HALO science flight. Highlights of the flight were long stretches of PSC observations by the WALES lidar, crossing of the subtropical jet north of Ireland with ozone going down from 900 ppbv to as low as 25 ppbv and high partriculate NOy at the same flight level, and a flight leg under defined constant solar zenith angle conditions for chemistry observations by the mini-DOAS instrument.

HALO and Falcon are performing coordinated flights today to probe gravity waves over Southern Scandinavia. (HALO research flight PGS_11). We took the opportunity of having both aircrafts at the apron for a group photo. (Photo by Sonja Gisinger, DLR)
Group photo with HALO and Falcon

Gravity waves over Iceland were the aim of HALO research flight PGS_10 today. A hexagon flight pattern was performed for tomographic observations of the gravity waves by the GLORIA imaging infra-red spectrometer, together with the release of drop sondes. Moreover this flight provided important measurements inside cold cirrus clouds.

The figure by Isabell Krisch and Peter Preusse, FZ Jülich, shows the flight path, overlaid on the predicted gravity wave field.

Flight path of PGS_10 and predicted gravity wave field
HALO research flight PGS_09 into the high Arctic north of Greenland took place under almost continuous PSC coverage. Excellent lidar observations were performed, coordinated with overpasses of the CALIPSO satellite, together with other important measurements.

(Photo by Steffen Gemsa, DLR).

PSCs on research flight PGS_09
HALO is in the air again for research flight PGS_08 towards Iceland, Greenland and Spitsbergen. (Photo by Björn-Martin Sinnhuber)
HALO leaving for PGS_08
The HALO research flight PGS_07 today was performed very successfully. The flight went south from Kiruna, over Denmark and back along the Norwegian coast. A first quicklook of the data suggests exciting findings with enhanced NOy and nitric acid containing particles at HALO flight levels. (Photo by Björn-Martin Sinnhuber)
HALO is back after a successful flight

Today we prepared HALO for a long science flight from Kiruna towards Greenland. Unfortunately, the flight had to be cancelled and HALO pulled into the hangar again due to prohibitive ground conditions with icing of the aircraft. Weather conditions did not improve during the day, so we are now planning for a HALO science flight for tomorrow, 18.01.2016. (Photo by Björn-Martin Sinnhuber)
The flight had to be cancelled

After a successful 8 hour science flight, HALO has now arrived in Kiruna this evening. This flight took HALO from Oberpfaffenhofen south to 35°N, around Malta and then up to 72°N before coming in to Kiruna, providing measurements from the edge of the Arctic vortex right into its centre. With the arrival of the Falcon aircraft earlier today, this marks the start of the first Kiruna phase of the joint POLSTRACC/GW-LCYCLE/SALSA campaign.
HALO arrival

With the completion of the early winter survey flight yesterday, 21 December 2015, we now conclude the first phase of the POLSTRACC/GW-LCYCLE/SALSA mission in Oberpfaffenhofen. The survey flight went from Oberpfaffenhofen northwards, around Spitsbergen at 81°N, and back over Scandinavia (see actual flight path shown). First results look very promising with many strong tracer filaments, and Arctic air masses on the northernmost flight leg. There were still some instrumental issues, but overall most instruments worked very well again and promise excellent data. An ozone sonde launch and ground-based lidar operations were coordinated with the station in Ny-Alesund, Spitsbergen: thanks to the AWI staff for the great collaboration. This Arctic stratospheric winter seems to be exceptionally cold so far and the early winter measurements from our flights provide an excellent reference for the upcoming measurements from the Kiruna phases.
Flight Path

HALO has just started for the early winter survey flight. The flight today probes the early polar vortex and leads into the Arctic around Spitsbergen, to Scandinavia, and back to Oberpfaffenhofen. (Photo by Wolfgang Woiwode, KIT)
North Flight
The first long science flight of the joint POLSTRACC/GW-LCYCLE/SALSA mission was completed successfully (see photo by S. Gemsa, DLR). The flight profile was particularly tailored to match the scientific objectives of the SALSA mission component. As usual at the beginning of a mission, there are still some issues regarding instrument reliability and performance. The next scientific flight is scheduled for next Monday.
SALSA Flight
A three hours instrument test flight was completed and turned out to be very useful. Some instrumental issues have been identified and are being fixed right now. (PLANET screen shot shows flight path.)
Test Flight
The inflight EMC test has been completed sucessfully (see photo by P. Preusse, FZJ). Flight planning for the scientific flights is in progress.
EMC Flight
The EMC flight is now scheduled for Tuesday 08.12.2015 and we are considering the options for a first long science flight later that week. Flight planning is in full swing (see photo by T. Leder, DLR).
Flight Planning

All necessary documentation needed for achieving the Permit to Fly (PfF) has been submitted to the Federal Aviation Office (Luftfahrtbundesamt, LBA). The pre-briefing for preparing the EMC flight has been completed today. Count-down plans for a possible flight on 3 or 4 December 2015 have been agreed on. We are now waiting for clearance from the LBA.

The ground-based EMC tests have been completed successfully on 17 and 18 November 2015. Short status and planning meetings are scheduled for 25 November 2015 (11 am) and 1 December 2015 (2 pm). The functionality of the IRIDIUM satellite link as high-latitude back-up for INMARSAT has been tested successfully on 23 November 2015 to allow chat funcionality for operators also north of ~70°N. (Photo by Wolfgang Woiwode, KIT)
EMC Test
The Integration Phase of the POLSTRACC/GW-LCYCLE/SALSA payload has started. The instrument integration will be finished until mid of November and will be followed by certification and ground-based EMC tests. The inflight EMC test is scheduled for the first week of December.
Integration Phase

The Critical Design Review of the combined HALO payload for POLSTRACC/GW-LCYCLE/SALSA and WISE has been performed successfully on 23 June 2015, and no major technical problems have been identified. "Design Freeze" is scheduled for 17 July 2015. The finalization of the instrument Interchange Control Documents is scheduled for mid of September 2015 and will be followed by the "Final Critical Design Review" at the beginning of October 2015.

The Critical Design Review of the POLSTRACC-Payload of HALO is scheduled for 23 June 2015 at DLR, Oberpfaffenhofen.

The POLSTRACC mission will be presented at the European Geosciences Union General Assembly 2015 (Vienna, 12-17 April 2015) in the AS3.12 Polar Ozone and Polar Stratospheric Clouds Session on Thursday, 16 April.

Flight planning associated to the joint POLSTRACC/SALSA/GW-LCYCLE (PGS) campaigns was exercised at the Mission Rehearsal at DLR-IPA, Oberpfaffenhofen.

The instrument test integration during the "Stellprobe" (02.-06.02.2015) at DLR, Oberpfaffenhofen was finished successfully. On 05.02.2015, the Preliminary Design Review was performed and the timeline for the mission preparation phase was refined. During the Status Meeting at the same day, logistic aspects of the campaign phases in Kiruna and scientific flight scenarios were discussed. The Mission Rehearsal is scheduled for 26.-27.03.2015 at DLR, Oberpfaffenhofen.

The "Stellprobe" is scheduled for 02.-06.02.2015 at DLR, Oberpfaffenhofen. In the same week, a Status Meeting will take place at the same location.

POLSTRACC General Meeting at KIT, Karlsruhe: Discussion of the timeline, payload, flight operations, certification and logistics of the joint POLSTRACC, GW-LCYCLE and SALSA campaigns. Data products for scientific flight planning are presented and a Mission Rehearsal is planned for early 2015 at DLR, Oberpfaffenhofen.

POLSTRACC Kick-Off-Meeting, DLR Oberpfaffenhofen

POLSTRACC/ROMIC meeting at KIT, Karlsruhe: The scientific objectives of POLSTRACC/GW-LCYCLE are sharpened and the HALO payload configuration is discussed.