About the author:
Gertrud Nöth is deputy head of the Press and Public Relations at the Deutscher Wetterdienst (DWD), Germany’s National Weather Service. She has talked to DWD weather forecaster Christian Paulmann who spent six austral summer seasons at the German Neumayer Station in Antarctica. In this contribution to Polar Prediction Matters, Nöth writes about Paulmann’s meteorological work, about DWD’s role in Antarctica and, about how the COVID-19 pandemic has complicated weather forecasting in the southern high latitudes.
The original version of this article (in German) has been published here.
Antarctica is the driest, windiest and coldest continent on Earth, with an annual mean temperature of minus 49 degrees Celsius (°C). The German Neumayer Station is in Dronning Maud Land (DML), where, alongside Germany, ten other countries operate research stations, which can be reached by air or sea, with ease and safety of access being weather-dependent. This is where Germany’s National Weather Service (Deutscher Wetterdienst, DWD) comes in.
In terms of weather forecasting, Antarctica is classified into four regions: Germany, and thus the German Weather Service, provides forecasting services for Dronning Maud Land (DML) within the so-called DROnning Maud Land Air Network (DROMLAN) network, a non-profit organization launched in July 2002. To the west of the DROMLAN territory, responsibility for weather forecasting and consultations lies with the British Met Office, to the east with Australia, and in between, including the geographic South Pole, it is with the National Weather Service of the United States.
Named after Norway’s first Queen Maud, the boundaries of Dronning (Norwegian for “Queen”) Maud Land (DML) territory have not been officially defined, but it extends approximately from 20°west to 45 east and from about 65°south over the coastal ice shelves to about 85°south. That is well over 2,000 kilometres from north to south, and along the east-west coastline, DML stretches about 2,500 kilometres.
Eleven countries (Belgium, Finland, Germany, India, Japan, the Netherlands, Norway, Russia, Sweden, South Africa, and the United Kingdom) operate research stations in DML under the terms of the Antarctic Treaty, some of which are manned all year round. One of them is the German Neumayer III Station on the Ekström Ice Shelf at 70°40’S 8°16’W. The station can only be reached and therefore supplied safely by air and sea during the austral summer between late October and early March. But even during this period, weather is the limiting factor for all human activities. Getting there, as well as moving around and doing research, requires meteorological information to ensure safe operations – and this is the DWD’s task in the DML region.
“These assignments during the Antarctic summer on site give you a feeling of adventure. However, they demand a great sense of responsibility and a high level of risk awareness, independence and flexibility as well as social and professional competence“, says Christian Paulmann, graduate meteorologist and team leader of the DWD’s Antarctic consulting and shipboard meteorological services and often on-site himself. “You are on your own in many extreme situations. But all in all, I can say that I am always rewarded with a unique experience in a hostile but fascinating world.”
But let’s start at the beginning.
Six Hours Instead of Ten Days
It usually takes at least ten days to sail to DML from Cape Town, some 4,000 kilometres away. Since 2002, DROMLAN have used the limited time window available for international research during Antarctic summer very effectively to transport people and supplies to this part of the Antarctic. Air supplies can be delivered to the three runways in DML by intercontinental aircraft from Cape Town within five to six hours. Within Antarctica, people and supplies are transported by specially equipped smaller aircraft and helicopters.
The DROMLAN season is divided into three time periods: between mid-October and laate November, a DWD meteorologist based in Cape Town supports all logistics activities to, and in, DML. Between late November and early February, a DWD meteorologist lives and works at Neumayer Station in DML. During a third period from late January to early March, a DWD meteorologist again provides support from Cape Town.
Specially Trained Meteorologists
Every year, nine employees from the German Alfred Wegener Institute (AWI) running the station spend the winter at the Neumayer Station, including a cook, a doctor, who is also the station leader, and various scientists. They remain at the station for about 15 months. During the austral winter, they are virtually cut off from the outside world from a meteorological point of view. Flights can only be operated in emergencies and at considerable risk, and boat trips are impossible. Some of the overwinterers do actually receive a meteorological induction from the DWD and AWI before their trip to Antarctica, but this only covers weather observation, the basics of Antarctic weather and how to utilize the information available.
The DWD’s Marine Meteorological Services division in Hamburg provides them and the entire international DROMLAN community with support for a range of operations and requirements. DWD has five meteorologists who are specially licensed and trained to provide Antarctic forecasting services. Outside the DROMLAN season, meteorological consultations are only provided on special request.
Sensitive Start and End Times
“From a meteorological point of view“, says Christian Paulmann, “experience shows that the weather during phases 1 and 3 is much less stable than in December and January, the Antarctic ‘midsummer’. This is due to the solar radiation, which varies greatly over the course of the year and which is also crucial to life and survival in Antarctica. Here, we are talking about the transition from the polar night with no solar radiation to the polar day with 24 hours of sunshine. The transitional seasons are associated with a variety of very distinct degrees of change that happen at a different speed, for example in the ocean, on the Antarctic ice sheet, and in the atmosphere. This, in turn, has a huge impact on weather and, above all, storm activity, particularly during spring between October and November.”
Unfortunately, these periods coincide with the beginning and end of the DROMLAN season where logistics are extremely important: in these time windows, the entire infrastructure required for flight operations to Antarctica has to be set up and dismantled, and most of the people and freight have to be transported to and from DML. This is why the work of the Cape Town-based meteorologists is so important at the beginning and end of a DROMLAN season. Weather conditions in phase 2 are slightly more stable but, according to Christian Paulmann, “all three phases are challenging“. Tongue in cheek, he adds that no one has yet written a book on weather forecasting in Antarctica. In other words, the experience of DWD meteorologists plays a key role in interpreting and mastering the wide range of Antarctic weather events in such a way that meteorological advice can be guaranteed for air and ship crews or scientists on site.
Flights, as well as supply trips by ship to DML depart from Cape Town. The partners for intercontinental flights between the end of October and the beginning of March are the Antarctic Logistic Centre International (ALCI, Cape Town, South Africa) and the Norwegian Polar Institute. For continental flights within Antarctica, other aircraft operated by ALCI and sometimes AWI’s POLAR aircraft fleet are used. The German research icebreaker RV Polarstern also departs from Cape Town for the Neumayer Station during these months, as well as supply ships sailing to other research stations in DML. The British operator White Desert, a for-profit business, also organises intercontinental and continental flights, but only in the high-price tourist sector. Cooperation between forecasters and White Desert is growing, both for reasons of flight safety and to the extent that White Desert also assumes duties in the DROMLAN network and carries out weather observations.
Forecasting a Lot with Little Data
Up-to-date weather observations are rare in DML. In addition to the weather observations from temporarily manned research stations which are not fed into the global data network, there are about ten weather stations in this huge area. For the most part, the territory has no meteorological infrastructure to speak of. By way of comparison: the DWD operates around 2,000 meteorological measuring stations in the Federal Republic of Germany, distributed over an area of around 358,000 km2. The DWD’s meteorologists in DML are therefore highly dependent on other data sources. Alongside the few weather reports, they evaluate the data from the daily radiosonde ascents carried out at a handful of locations in DML as well as webcam images, for example from the runways at the DML stations Troll (Norway) and Novolazarevskaya (Russia). High-resolution images from polar-orbiting weather satellites are also a particularly important source of data, with a dedicated satellite reception system installed at the Neumayer Station for this purpose.
In addition, the meteorologists work with DWD’s weather forecast model as well as with weather forecast information provided by the European Centre for Medium-Range Weather Forecasts (ECMWF), the U.S. National Oceanic and Atmospheric Administration (NOAA), and the Antarctic Mesoscale Prediction System (AMPS) of the University Corporation for Atmospheric Research (UCAR, Boulder, USA). This information is transmitted to the meteorologist on-site at Neumayer station via a secure DWD SFTP server, e-mail, and the Internet.
Comprehensive Task Portfolio
With the help of this data basis, as well as special training and experience, DWD meteorologists at the Neumayer Station perform a comprehensive portfolio of tasks every day. At all DML research stations, work and experiments are carried out in the immediate vicinity of the stations, and research expeditions across the Antarctic continent or trips made to bases further inland are being planned here. For example, AWI maintains the Kohnen base 550 kilometres southeast of the Neumayer station, at an altitude of about 3,000 metres. During the summer months – when temperatures do not fall below ‑30 °C – the base is temporarily manned. “Whether and when the scientists leave for the base or return from there depends entirely on the weather. A reliable weather forecast is essential for such activities”, explains Christian Paulmann.
One of the tasks of the meteorologist at Neumayer Station is to provide marine forecasts for supply and research vessels travelling along the DML coastline. Despite the increase in air traffic to Antarctica, the sea route is still used, for example, to deliver heavy equipment to the ‘ice harbour’ in Atka Bay on the edge of the ice shelf. Roughly 10 to 18 kilometres northeast of Neumayer Station, mooring in Atka Bay presents an additional challenge during loading and unloading in bad weather as well as onwards transport of deliveries to the station proper.
Flight Schedules “Yes!”, Punctuality Not Necessarily
Most meteorological information is provided for aviation. The DWD meteorologists at Neumayer Station advise the crews on supply flights to the various national stations in DML, on research flights over the ice sheets and oceans and on helicopters, which mainly operate between ships and research stations.
Every season, there are around thirty intercontinental return flights, all operated by ALCI and NPI, between Cape Town and Dronning Maud Land. In addition, the British private company White Desert flies up to 30 times from Cape Town to a blue-ice runway in DML called Wolfs Fang Runway (WFR, formerly the first blue-ice runway in DML and originally called Blue One). Occasionally there are also unscheduled flights, for example for medically necessary evacuation or to transport high-ranking political delegations. Out of season, there may at the most be some emergency search and rescue (SAR) flights. Flight schedules do exist, but depending on the weather, a flight may sometimes arrive and leave with a week’s delay on one of the three blue-ice runways in DML. These runways are about three kilometres long and 60 metres wide. They are located on blue-ice fields where the bare ice is visible openly on the surface. Their advantage is that, due to the natural processes, there are hardly any snow deposits and yet they are so stable that heavy aircraft can land and take off on them. The reliable and robust Russian aircraft type Ilyushin IL76, which has an unladen weight of around 92,000 kilograms (92 tonnes), has proven particularly suitable here. More sensitive aircraft types – in terms of meteorological measurements – are also used, such as Airbus or Boeing, and business jets. Each aircraft type has different landing weather requirements, which poses a further challenge.
The DWD’s aeronautical meteorological service is responsible not only for the numerous airfields near research stations, but also for the three-blue ice runways managed by ALCI and NPI. These runways are located at the Russian Novolazarevskaya Station and the Norwegian Troll Station, both manned year round, and at the Perseus Airstrip, which has been in operation since November 2019 and is located close to the Belgian Princess Elisabeth Antarctica (PEA) Station only used in summer. Intercontinental flights to White Desert’s blue-ice runway WFR still obtain their meteorological information from an external South African company. White Desert now also relies on AWI’s and DWD’s DROMLAN meteorological services for their continental flights
Famous ‘Point of No Return’
“Another special challenge for the meteorologist is that no transport aircraft can fly to Antarctica and back without refuelling,” says Christian Paulmann. The flights from Cape Town take about six hours and the pilot can turn back up to about one hour before the scheduled landing time in Antarctica in order to guarantee a safe return to Cape Town; after that, the aircraft is past the famous ‘point of no return’. “For our meteorological consultations, this means that we often have to forecast exactly and in extremely narrow time corridors when a landing on one of the blue-ice runways is possible. In the last season 2019/20, we, unfortunately, had the first boomerang flight, but this was mainly due to extreme safety regulations imposed by an airline with little previous experience in Antarctica. Otherwise, there has not been a single boomerang flight since the first season in 2002/2003, where a pilot had to turn back before the point of no return due to deteriorating weather conditions,” said Christian Paulmann full of pride.
Experience the Weather as Forecast
In principle, the DWD meteorologists are on standby 24 hours a day, seven days a week for the two-month assignment at Neumayer Station. Officially, the working day starts at 6 a.m. and ends around 8 p.m. The word ‘day’ is to be understood in the best sense of the word – in the Antarctic summer the meteorologist only sees a few hours of the night. After inspecting the data, they prepare a weather report for the next four days for all stations in DML as well as an aeronautical meteorological report and a forecast specifically for the runways, both for the current day and for the following four to five days. This is followed by individual aeronautical meteorological forecasts for continental and intercontinental flights as well as for research flights. Scientists at Neumayer Station receive an additional separate weather briefing to enable them to plan their research work, and there are also individual consultations for land, sea and air expeditions for all researchers working in DML. The meteorologists must always take current weather data, if available, into account in the briefings and forecasts. Most consultations are sent by e-mail, but sometimes the information may be provided by phone, SMS, radio or personally.
“Many of these tasks initially appear routine, but due to the low spatial density of high-quality meteorological reports and the extreme climate conditions in Antarctica, the weather is almost always the limiting factor for research work. When preparing aeronautical meteorological reports, in particular, we must always bear in mind that there is no infrastructure here as we know it from other countries, such as double visibility measurements or wind masts on runways,” explains Christian Paulmann. “You are really in close touch with the weather and as a meteorologist, you experience first-hand if your weather forecasts are accurate. Special emphasis is on the parameters ‘contrast’ and ‘horizon’ as these are extremely important for flight safety, especially over snow and ice. They are used for three-dimensional orientation in airspace and play a subordinate role in civil aeronautical meteorological services outside the polar regions. The most impressive phenomena for meteorologists, however, are the storms. They can last up to a week and achieve such a brute force that they not only prevent flying and outdoor work but simply prevent us humans from surviving unprotected in the open air. “
Everything Different in Season 2020/21
The 2020/21 season would have been Christian Paulmanns’s seventh on-site assignment – but because of the COVID-19 pandemic, everything is different this time. The otherwise frequent intercontinental ALCI, NPI and White Desert flights have been reduced to only eleven in the 2020/21 season due to COVID‑19 restrictions. The start of the season was postponed three weeks to mid-November. Some countries are using the direct sea route to Antarctica instead of aircraft, including the German Alfred Wegener Institute with RV Polarstern, for example. Only one continental Basler BT-67 aircraft is operating in Dronning Maud Land at the moment, with many summer-only stations not being used at all this season. All other DROMLAN members have limited their activities to the bare essentials, e.g. the maintenance of stations and measuring instruments and of course replacing the station crews.
The deployment of DWD meteorologists has been adapted to this new situation: there are no on-site missions, neither in Cape Town nor at Neumayer Station. All meteorological consultations are provided remotely from the DWD’s Marine Meteorological Office in Hamburg. And this is uncharted territory: the few DWD meteorologists qualified in this field have the necessary professional expertise to do this, but they miss the closeness to the customer that is so important for such a sensitive forecast area as Antarctica. Caused by the huge lack in particular of aircraft weather observations, the numerical weather models are also suffering from COVID‑19 and associated restraints in global weather observations. The latter are crucial for both the quality of the models and their forecast period, and all the more so in areas with very little data.
The season was continued to be divided into individual periods among the DWD colleagues. On most days, the complete product portfolio was offered, although not for all stations. This means a ten-hour working day for remote meteorological consultation, too. In some periods where there was no air traffic, however, the meteorologists could limit their work to a few products per day and occasionally take a day off, although they continued to be on permanent standby.
The start of the season in November, supervised by Christian Paulmann, proved to be very tough due to very bad weather. The workload was high from the very beginning, with flight delays of several weeks. “But even from afar, I still feel ‘addicted’ to the Antarctic weather and the work for DROMLAN“, adds Christian Paulmann. For example, for the first time in his professional life, he had the chance to predict a mean wind speed of 90 knots (166 km/h) and gusts of up to 100 knots (185 km/h) at the edge of a deep low which, with a core pressure of 938 hPa, was moving directly along the western DML coast. Although hurricanes can reach even higher wind speeds, the wind fields of the cyclonic storms in mid and sub-polar latitudes are much larger and last much longer. In some places, for example, the storms reached speeds of over 60 knots (wind force 11–12) over several days! This is invariably accompanied by a white-out, extremely dangerous. Everyone was anxiously waiting to see how the rest of the season will turn out. Mid-December to the beginning of February was Christian Paulmann’s next turn for remote consultation.
About the Antarctic climate
With an annual mean temperature of minus 49 degrees Celsius (°C), Antarctica is the coldest region on Earth, with East Antarctica being colder than West Antarctica. Annual mean temperatures on the plateau in the interior of the continent, which reaches an altitude of 4,000 metres, are ‑55 °C and thus colder than the coastal region where temperatures can reach 0 °C in summer. The Antarctic Peninsula, which protrudes far to the north, is the warmest region in Antarctica. On its western coasts, annual mean temperatures are only slightly below 0 °C, and in summer temperatures have occasionally exceeded 15 °C. Antarctica is also the windiest region on Earth, with average speeds of 33 km/h. Typical are the catabatic fall winds, which blow from the polar plateau towards the coasts and can be accompanied locally by peak gusts of up to 350 km/h. In some coastal sections, there are over 300 storm days (from wind force 9) per year. In addition, there are deep low-pressure systems in mid- and sub-polar latitudes which are particularly active in coastal areas and especially in the transitional seasons. Antarctica is the driest continent on Earth, a desert of snow and ice. It has low levels of precipitation, even though snow falls on an average of 170 days per year. Annual precipitation ranges from 200 mm in the interior to 600–1,000 mm on the coast. Fog is rare and only occurs along the coast and on islands.