Daily Editorial Analysis

Why is there no snowfall in Kashmir? (GS Paper 3, Environment)

Why in news?

• January is usually the month where Kashmir and Himachal Pradesh are blanketed with snow. This winter has, however, seen these regions extremely dry. Places like Gulmarg and Pahalgam, known to be popular destinations for skiing, have been unable to offer avenues for the winter sport.
• Himachal Pradesh, a State famous for several mountain resorts, has witnessed dry slopes and valleys of brown grass.
• Records from the India Meteorological Department (IMD) suggest that Himachal Pradesh has registered its driest January since 1901, with a 99.7% shortfall in January rain compared to what is normal. Until this year, the record for the driest January was 1996, which reported a 99.6% shortfall.

What is the reason for the lack of snowfall?

• Snowfall requires adequate moisture as well as atmospheric temperatures to be zero degrees or less. Temperatures were fairly low since December.
• An analysis by the IMD in mid-January reported that maximum temperatures are running 5-8°C ‘below normal’ over the plains of north India since December 29. Minimum temperatures were also below 4 degrees Celsius at many stations of northwest India for most of January. This also resulted in a very dense fog persisting over the plains of northwest India.
• Several cities in the region reported zero visibility over the entire north-Indian plains from Amritsar to Dibrugarh across Haryana, Delhi, Uttar Pradesh and Bihar.
• While moisture and high aerosol loads contribute to fog, there were three major reasons behind the lack of snowfall and consequently  intensifying cold waves over north India. These were —

1. a drastic fall in Western Disturbances (WDs) over northwest India;
2. prevailing El-Nino conditions; and
3. the absence of a strong jet stream.

How do these three factors influence snowfall?

• Western Disturbances are storms that originate in the mid-latitude regions and travel thousands of kilometres to bring rains to northern India.
• Such WDs in the winter dissipate fog and increase the sunshine incident on the ground raising temperatures. They also, when the temperatures are low, result in snowfall and water being available as snow melts.
• The melting glaciers contribute to the water available in the Ganga, Indus and Yamuna. On the other hand, they can also bring in hail, which is destructive to standing wheat crop.
• Usually, 5-7 WDs impact northwest India during December to January. But this winter there have been none. There were two WDs in this period, but their impact was mainly confined to Gujarat, north Maharashtra, east Rajasthan and Madhya Pradesh. As a result of the lack of these rains, the Western Himalayan Region got 80% less rain than normal.

El-Nino impact:

• Prevailing El-Nino conditions over the equatorial Pacific Ocean, or warmer ocean temperatures, may also have had a role to play. However, irrespective of El Nino, or the converse, La Nina, the number of WDs in December and January have been on a decline.
• In the winter of 2022-23 (December and January), India reported its hottest ever December. The northwest region, which usually reports nearly a third of its rainfall during this season, saw an 83% rainfall deficit.

Global warming:

• In recent years, there has been a rise in these WDs in February and March that have caused flash floods, particularly in Uttarakhand and Himachal Pradesh. Last year for instance, saw record-breaking rain in February. In general, the traditional pattern of WDs have been disrupted since 2019.
• These instances of extended dry periods and intense wet spells are characteristic of global warming, as several meteorologists and climate scientists have been pointing out in recent years.

What role do the jet streams play?

• Jet streams are powerful winds, ranging from 250-320 kmph, travelling at about 12 km above mean sea level.
• They are carriers of the western disturbances but the lack of moisture means that so far, they have been contributing to the subsidence of cold air thereby enhancing the cold over north India.
• The jet streams set in after the withdrawal of the monsoon are also able to draw in moisture from the Arabian Sea.
• In recent years, the jet stream has been shifting northwards. This, emerging research suggests, is a consequence of a warming in the Arctic seas that affects the natural gradient of temperature necessary to ensure the strength and direction of the jet streams.

Is India in the midst of a snow drought?

• Snow droughts are periods characterised by significantly below-average snowfall or a lack of snow accumulation over an extended period, particularly in regions where snow is a regular and expected part of the seasonal climate.
• They are becoming increasingly prevalent globally. One notable instance of snow drought occurred in the Sierra Nevada in 2014-15, causing widespread repercussions such as water supply disruptions and losses of $2.7 billion in the agriculture sector alone. Similarly, the Italian Alps faced a critical snow drought in the early 2020s.
• The March 2022 snow water equivalent (SWE) anomaly reached a century-low, contributing to critical hydrological challenges in the Po and Adige rivers, leading to the worst-recorded hydrological drought in the summer of 2022.
• These events are not isolated but part of escalating patterns. Studies reveal an 8.4 percent decline per decade in Alpine snow cover between 1971 and 2019, with recent research highlighting a 36-day reduction in snow cover duration compared with the long-term average – an “unprecedented” decline over the past 600 years.

Trend in the northern hemisphere:

• Another study exposes a concerning trend in the northern hemisphere, with declining snowpacks in 82 of 169 river basins crucial for winter water storage. Published in January 2024, it additionally emphasises a non-linear relationship between snow and global temperature, raising concerns about widespread snow loss with continued warming.
• For context, on approximately one-third of the days in 2023, the average global temperature exceeded pre-industrial levels by at least 1.5°C. The Copernicus Climate Change Service of the European Union officially designated 2023 as the warmest year on record.

India connection:

• What’s worse is that the Hindu Kush Himalayan (HKH) region, home to approximately 54,000 glaciers, is experiencing accelerated warming, with a rate of 0.2°C per decade over the last 50 years. There’s been a 1-3 percent decrease in SWE in the Ganga and Indus River basins over the past 40 years.
• The HKH region had minimal snowfall in 2023, labelled by some experts as a “no snow year” and attributed to the absence of intense western disturbances.

Way Forward:

• In the end, the rising frequency of these events underscores the pressing need for a comprehensive understanding, proactive mitigation strategies, and adaptive measures to navigate the ever-changing dynamics of snowfall patterns.
• Only that can ensure a sustainable and resilient future for regions affected by snow droughts.