Govt working to better predict weather and climate events, control rains

The plan involves launching at new satellite in collaboration with ISRO for weather profiling in the atmosphere, and increasing by ten-fold, the number of observation stations, rain gauges, radiosonde (a meteorological device that measures atmospheric parameters and transmits it back to ground stations) and wind profilers deployed in the country. 

Apart from that, the ministry is also looking to develop expertise where it can deploy aircraft for cloud intervention and observation, Ravichandran explained.

Ravichandran added that as the country grapples with extreme weather events, including severe and long heatwaves and uneven and excessive rainfall, the ministry also plans to incorporate artificial intelligence and machine learning technology with physics-based numerical models in its forecast models to have a better indication of such conditions in the future.

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For context, the ministry of earth sciences is tasked with providing forecasting services for weather, climate, ocean and coastal state, hydrology, seismology, and natural hazards. 

It is also mandated to explore and harness marine living and non-living resources in a sustainable manner for the country and to explore the three poles of the Earth (Arctic, Antarctic and Himalayas). 

The ministry also primarily runs two schemes—the Prithvi programme and the deep-sea mission. The new project or programme will be in addition to these.

Decoding the weather

According to Ravichandra, not only are there more frequent extreme weather events, but even normal seasonal and climactic conditions have changed significantly, which make them extreme.  

According to him, earlier, clouds, especially during the monsoon season, used to be spread across a larger area, but now they are small and intense because of the higher water-holding capacity of the atmosphere. 

“What is happening now is that it is holding more water vapour and then suddenly it is falling; that is what is extreme right now. Spatial distribution of rainfall has changed, which means somewhere we are receiving more rain and no rain at all in other places, creating two problems—flooding and drought," Ravichandran said.

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“In the monsoon period earlier, it would rain for about 80-120 days; at least 80 days and spread across the country. Now, in eight days, everything is pouring. Both spatial and temporal patterns are changing due to warming and water holding capacity of the atmosphere," the earth sciences secretary added.

Following last year’s patchy monsoon and prolonged dry spells caused by El Nino and before the start of the June-September southwest monsoon season, the India Meteorological Department (IMD) had forecast that the country would record normal to above-normal rainfall this monsoon season. 

Clouded by challenges

After the hot, humid and severe heatwaves witnessed in June, surplus rainfall in July in some regions in the northeast has caused flood-like situations there.

Consequently, to predict weather and climatic conditions with a greater degree of accuracy, Ravichandran said that the government needs to bolster its infrastructure, install radars and satellites and develop expertise to intervene in clouds.

“The problem is our ability to understand the atmosphere is less. Tropical weather is much more complex than mid-latitude and polar regions. We are unable to capture the processes that happen in about 10-12 kms. Today morning, if some clouds form and it rains in the evening, we are unable to forecast it. Suppose an earthquake is happening. Can we forecast? No—there is no science. There may be science, but we don't know. Similarly, if any problem is happening within 12 kms, it is very difficult to forecast," he noted about the challenge in forecasting weather accurately. 

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For context, at present, the IMD-MoES weather modelling system has a resolution of 12 kms, whereas the ministry plans to improve the resolution to six kms. Similarly, the resolution of the regional modelling system is expected to be improved from three kms to one km.

“To address the issue and understand weather variabilities, we need to have more observations and increase the frequency of observations. The second thing is we need to go for higher model resolution. Now, we have model resolution of about 12 kms. To go to four-six kms, we need more compute power. Therefore, we are planning to increase our AWS (automatic weather stations), radars, radiosonde, rain gazers by ten-fold and install at least one satellite for profiling of each region," Ravichandran said.

A plan for all seasons

The central government currently maintains an infrastructure involving roughly 39 radars, 1,000 AWSs, around 60 radiosondes and approximately 5,000-6,000 rain gauges.

“We want to know what is happening in the entire atmosphere and for that, we need a dedicated satellite to probe the atmosphere columns. As of now, we have none. At present, we are indirectly inferring from various satellites, like cloud motion vectors, but we want to profile each height," Ravichandran expounded on the plan to monitor various weather profiles through satellites. 

“It could be one or two satellites. I am not sure of the exact number yet, but ISRO will be helping us with it."

“Another thing we are now going for is a numerical model or science-based model that has many (weather) assumptions. Because of the assumptions, we will be able to capture the atmospheric processes, maybe 80%. To get better accuracy than this, we need to fuse both data-driven model (AI and ML) and numerical model," the secretary said.

This will help the ministry predict weather events more accurately and use that information to take better countermeasures in consultation with other ministries and stakeholders to combat its harmful effects. 

The next step

The ministry has already started working on the project, and it is now engaged in deciding the technical and observation requirements of the project. 

Following this, it plans to invite inputs from various other government bodies and ministries for their requirements and other details.

“Hopefully, by November, we will put this up to the government. It is early to comment on targets and fund requirements. First, we will have to ask for budget approval. Once it is approved, then only we will be able to set a target," said Ravichandran. 

“It will be a new project aiming at improving our forecast and a little bit to intervene in the weather."

“If we see clouds or rain coming on 15 August, I can fly and disturb the weather and stop the rain for some time. It is called cloud intervention. Cloud seeding, a part of cloud intervention, is also there in the pipeline. We will need aircraft with observation (systems) for that, which is also a part of our plan," Ravichandran explained.