Last Update: 7 Jan 2013
VERDI: Vertical Distribution of Ice in Arctic Clouds.   Inuvik, Northwest Territories, Canada, 10 April - 20 May, 2012

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VERDI — A Study on Arctic Clouds

Arctic Climate Change

The Arctic is the region on our planet where climate change has its strongest effects, with the highest temperature increase observed and predicted. This is partly due to the peculiarities of the Arctic, such as the albedo feedback effect: Warmer temperatures cause snow and ice to melt, and darker soil or water replaces the bright snow/ice surface. As darker surfaces absorb more solar energy than white ones, the surface temperature is increased even more.

The Arctic heats up the most: This plot shows the difference (in centigrades or Kelvin) between the average spring (March–May) temperature of the years 1998–2011 and of the years 1963–1992. Source: NASA GISS.

The Role of Clouds

Clouds also play an important role in the Arctic climate, as they block solar energy from the surface (cooling effect), but they also keep thermal infrared radiation from escaping from the surface into space (warming effect). Because the Sun reaches the Arctic only during a part of each year, Arctic boundary-layer clouds tend to have a warming effect on a global and annual average. However, an accurate desciption of these clouds in climate models requires solid knowledge about their occurence and their actual properties. One of the properties that influences the optical properties of the clouds is their ice content. At temperatures between −40 and 0 degrees, clouds consist of a mixture of liquid water droplets and ice crystals. Only below −40 degrees all water is frozen. In order to describe the optics of such clouds, we need to know the amount and the distribution of ice in those clouds.

Glories like this are products of light scattering by water droplets. Their structure contains clues about the droplet size distribution within the top layer of the cloud.

About us

The scientific expedition VERDI (short for Vertical Distribution of Ice in Arctic Clouds) is a cooperation project of various German research institutes with the goal to measure the microphysical and optical properties of Arctic boundary-layer clouds, and to investigate the effects that those clouds can have on the energy budget in the Arctic atmosphere. The VERDI participants have successfully performed airborne measurements of the microphysical and radiative properties of clouds in the Canadian Arctic (based in the town of Inuvik in the Northwest Territories) in April and May 2012, and are now working on the data processing and evaluation.

Our Team comes from several German research groups:
Leipzig Institute for Meteorology (LIM) Spectral and hyperspectral solar radiation
Alfred Wegener Institute (AWI) Aircraft operation, logistics, cloud/aerosol lidar, sea-ice thickness, sun photometry
Karlsruhe Institute for Technology (KIT) Diffraction patterns of cloud particles
Forschungszentrum Jülich (FZJ) Microphyical sampling of cloud particles
Max Planck Institute for Chemistry, MainzAerosol characterization
Institute for Atmospheric Physics, Mainz Microphysical sampling of cloud particles
Institute for Atmospheric Physics, German Aerospace Microphysical sampling of cloud particles

For a more detailed overview of the scientific background of VERDI, visit the Science link on the left menu.

Time Line 2013

28-29 MayData Meeting Mainz

Time Line 2012

26-27 NovData Meeting Leipzig
23-25 MayDe-Integration Muskoka
21-22 MayFerry to Muskoka
25 Apr-20 MayVERDI Flights
24 AprReconfig to VERDI
20-23 AprBird Flights
18-19 AprFerry to Inuvik
17 AprTest Flight Muskoka
10-16 AprIntegration Muskoka
27 Feb-7 MarIntegration Bremerhaven

Time Line 2011

31 DecemberDeadline for personal forms for AWI
30 NovemberDeadline for technical documentation of instruments
6-7 OctoberPreparation meeting Bremerhaven (minutes @)


24 May 2012

VERDI is history! The instrumentation has been taken off our reliable Polar 5 aircraft. Everything is stored in boxes and is waiting for being shipped back to Germany; some boxes are already on their way. Muskoka has warm and sunny weather, and everything is lush and green. A huge contrast to the freezing cold we experienced in the beginning of VERDI. Thanks to all who helped us: Lake Central Air Services, Kenn Borek Air, the Aurora Research Institute, the town and people of Inuvik, Environment Canada, the DLR Inuvik Satellite Station staff, and most of all Martin and Franzi for their work and patience with us!

19 May 2012

The Polar 5 departs from Inuvik to go to Muskoka airport, Ontario. The trip includes one overnight stay in Winnipeg.

18 May 2012

We packed the equipment and prepared the Polar 5 for the ferry flight back to Muskoka, Ontario. The last official group meeting at 6 pm was combined with the first barbecue of the year, on the sunny porch of Aurora's great row houses.

17 May 2012

Even during our last research flight, we found some ice crystals in the same cloud region!

16 May 2012

The third flight into the same cloud area. A few ice crystals.

15 May 2012

The second flight into the same cloud area. Some ice particles were observed, although it was not very cold.

14 May 2012

Finally flying again. There is a low cloud deck on the southern Beaufort Sea, and it seems today's flight is the first of a series in the same cloud area.

12 May 2012

A few days off, because of warm air from the south, so there won't be any ice in the clouds. Colder air should come back in the next few days.

10 May 2012

Flight into a low cloud which contained no ice. A second higher layer was just dissolving when we arrived to probe it.

8 May 2012

Flight into two low cloud decks over the MacKenzie delta. Thin aerosol was observed above.

7 May 2012

Day off.

6 May 2012

Ground day with some repair works, waiting for spares, and too complex clouds. The weather forecast doesn't look very promising, either.

5 May 2012

Flight over and through a low cloud layer over the Beaufort Sea, while a weather system with complex and high clouds is moving in toward Inuvik from the south. The flight was successful, but a second in-situ probe failed for unknown reasons.

4 May 2012

No flight today. We lost one power circuit on yesterday's flight and need to look into it.

3 May 2012

Flight into a patchy, low cloud that was further north than it should have been according to the forecast. Although it was thin, we could probe it at three altitude levels.

2 May 2012

Messy cloud situation; no flight today.

1 May 2012

Messy cloud situation; no flight today.

30 April 2012

Today's flight brought us into an extensive mixed-phase clouds, and we probed various types of ice particles at many different altitudes between 500 and 12,000 feet.

29 April 2012

Today we probed a very nice, stable layer of low clouds. They contained both liquid water droplets (which were 20 micrometer in size at the top of the cloud, and 10 micrometer in the middle) and a few ice crystals.

28 April 2012

The aircraft is grounded for a day for maintenance.

27 April 2012

Low clouds, but conditions are good enough for flying. We take this opportunity and do two flights in a row! Good conditions with low clouds over the sea ice, and no high clouds above us. We observed ice particles in the mid-level clouds, while the low clouds (which form from the open water leads in the ice) contained only super-cooled liquid water droplets.

26 April 2012

Low clouds, no flight conditions.

25 April 2012

First (test) flight with the in-situ instrumentation. The instruments work fine; some require heating in this cold environment.

24 April 2012

No flight today. The Polar 5 is re-configured for the full VERDI instrumentation: The EM Bird is taken off, and PMS cloud-particle sensors are installed.

23 April 2012

Third science flight for the sea-ice project.

22 April 2012

Second science flight for the sea-ice project.

21 April 2012

First science flight for the sea-ice project.

19 April 2012

The Polar 5 and the crew have arrived in Inuvik!

9 April 2012

The Polar 5 has arrived in Muskoka, Ontario. In the next days, the aircraft will be prepared for the VERDI measurements.

5 April 2012

The VERDI research license has been issued by the Aurora Research Institute, Inuvik, Canada.

6 March 2012

A test flight with the P5 and the VERDI instrumentation was conducted with views of Heligoland, Bremen, and Bremerhaven harbour at night.

31 January 2012

The Environmental Impact Screening Committee (EISC) has exempt VERDI from the environmental screening procedure. With this document, this prerequisite for the research license has been fulfilled.

27 January 2012

The instrument integration in Bremerhaven has been postponed to the 9th week of the year, with test flights scheduled for Mon/Tue 5/6 March. The sea survival training at AWI is on 29th Feb and 1st March.

9 January 2012

The NWT Research License Application for VERDI has been submitted.

22 December 2011

The VERDI website is released.

21 December 2011

The Environmental Impact Screening Application and the Yukon Scientists and Explorers License Application for VERDI have been submitted.

VERDI Home   Eike Bierwirth, LIM, Stephanstr.3, 04103 Leipzig, Germany.
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