Latest News Editor's Choice

News / National

Zimbabwe's US$400 000 cloud seeding programme takes off

by Staff reporter
15 Jan 2024 at 05:14hrs | Views
IT'S a humid Friday afternoon and there are only two aircraft on the tarmac at the Joshua Mqabuko Nkomo International Airport in Bulawayo that are about to take off.

One of them is a commercial aircraft bound for South Africa with a lot of passengers on board. The other one is a five-seater private plane ready to take off with just two people, a pilot and a passenger.

The passenger is Ms Violet Ngwenya, a Meteorological Services Department (MSD) technician.

She is about to embark on the ambitious journey into the realm of atmospheric manipulation — cloud seeding, a Government initiative to enhance rain probability in the southern parts of the country.

Ms Ngwenya is carrying a brown cylinder-shaped container containing hydrophilic substances, set to be release into the clouds to trigger the formation of rain droplets, cleansing the polluted air below.

In the quest to control weather patterns and combat the effects of drought, scientists have long experimented with cloud seeding. This process involves modifying clouds to encourage precipitation, primarily through the introduction of certain substances that serve as nuclei for water droplets to form around.

Cloud seeding typically involves the dispersion of substances such as silver iodide, potassium iodide or liquid propane into clouds. These substances act as catalysts, encouraging the formation of ice crystals within clouds and subsequently promoting the coalescence of these crystals into raindrops or snowflakes, depending on the prevailing atmospheric conditions.

One of the primary motivations behind cloud seeding is to address the impacts of climate change, such as prolonged droughts and erratic weather patterns.

A week ago, Government launched a US$400 000 cloud seeding programme for the northern and southern parts of the country to induce more rains in the wake of El Nino-induced drought and high temperatures.

Farmers in the Matabeleland region hailed the introduction of cloud seeding saying the initiative could come in handy considering that their crops were already showing moisture distress and dwindling water sources for livestock.

Ms Ngwenya, one of two cloud seeders based in Bulawayo and servicing the southern parts of the country, started cloud seeding nine years ago.

She believes that induced rains could be a solution, especially under the El Nino weather conditions.

Likening cloud seeding to a pregnant woman who is struggling to deliver a child prompting doctors to induce an assisted delivery, Ms Ngwenya said the process enhances rainfall.

"We induce the clouds to give rains. The clouds would be ready, but still not producing rain. So what we do is like what they do to pregnant women, they are induced into giving birth. So we would be helping the clouds to produce rain because sometimes they don't produce," she said.

Ms Ngwenya noted that despite cloudy and overcast skies in areas such as Bulawayo, it hasn't rained and she attributed it to the El Nino phenomenon.

She said cloud seeding is effective and could be the only hope for the Matabeleland region.

This comes particularly in the wake of MSD warning of heavy rains in some parts of the country including several districts in Matabeleland which were projected to receive torrential downpours of over 50mm from Thursday.

Ms Ngwenya said she first communicates with her colleagues in the office for directions before the plane takes off.

"So today we are going to Plumtree, Tsholotsho and West Nicholson. Before taking off, we have to communicate with our central forecast in Harare. Usually, at 11AM, there is some observation around the country and we use that to identify the cloud development around the country," she said.

"The central forecast is the one that identifies the areas that we should go to."

Ms Ngwenya said some of the areas that have benefited from the cloud seeding exercise since it started early this week are Nkayi in Matabeleland North, Kezi in Matabeleland South, Chiredzi in Masvingo and Zvishavane in the Midlands.

She said they can take up to four hours to conduct cloud seeding and the process depends on where the cloud is located.

"I have flown for up to four hours and it depends on the route. For example, if you go to Victoria Falls, it can take longer and today (yesterday) we are not going too far so we might take an hour," said Ms Ngwenya.

She said while airborne she would be communicating with the pilot on which cloud to approach.

Another cloud seeder Mr Batisani Ndlovu nicknamed "The Rainmaker" said there is evidence rains were received in the places that they seeded during the week.

 "Cloud seeding is one of the best ways of inducing rain. There is a type of convective cloud which we are supposed to induce. We don't seed all the clouds, there is a particular type of cloud and we know that when you seed that particular cloud, rains are imminent," he said.

"If you go right around the cloud and come back you will see that the windows of the aircraft are wet, then you will know that it will be raining. It does take time."

Mr Ndlovu said they sometimes fly between 8 000 and 9 000 feet high above sea level to cloud seed.

"While cloud seeding, we meet different kinds of weather phenomena. There is that cloud called the cumulonimbus, but that one is better because it gives you a warning 20km before you reach it," he said.

"The aircraft will be bumpy hence we try by all means to avoid such a cloud. Sometimes the cloud is so fast and you start feeling the turbulence, but we have experienced pilots and so far, we have not experienced any problems."

Source - The Chronicle