Over 20% of India reeling under drought, says US weather agency

Even as 2023 heads to be ranked as the warmest year on record globally, at least a fifth of India is undergoing drought, US national weather agency National Oceanic and Atmospheric Administration (NOAA) has said. 

“Drought conditions were confirmed over northern, eastern, and coastal southwestern parts of India on the India Drought Monitor, covering about 21.6 per cent of the nation, which is about the same as last month,” the US weather agency said.

This should raise concerns when over a third of India (based on data received by India Meteorological Department) has received large deficient rainfall since the beginning of October.  The NOAA came out with these findings on October 13.

Lands suffer low moisture

“September was drier than normal across large swathes of Asia,” said NOAA. Global temperatures in September were 1.44° C above the 20th century average of 15 °C, the US weather agency said.

According to the US National Centers for Environmental Information (NCEI), there is more than 99 per cent chance that 2023 could rank as the warmest year on record globally,  

NOAA said September 2023 was the warmest September globally in its 174-year-old history. This has resulted in a significant portion of the world’s agricultural lands continuing to suffer from low soil moisture and groundwater levels, while satellite observations showed stressed vegetation on all continents.

Warmest SSTs

“Record-warm temperatures covered 20 per cent of the world’s surface this September, which was the highest percentage of any month since the start of records in 1951,” the US weather agency said.

For the sixth consecutive month, September saw a record-high monthly global ocean surface temperature. It tied with August 2023 for the highest monthly sea surface temperature anomaly (up by 1.03° C) of any month in NOAA’s 174-year record, the agency said.

The US weather agency’s findings have been backed by the Bureau of Meteorology, Australia, which said global sea surface temperatures (SSTs) were warmest on record for their respective months during April-September 2023.

SSTs were above average across much of the northern, western and southwestern Pacific as well as the Atlantic and the Indian Ocean.  

Since the beginning of this year, NOAA’s National Centers for Environmental Information has begun calculating the global temperature anomaly every month based on preliminary data generated from authoritative datasets of temperature observations from around the globe. 

535th consecutive month

“September 2023 marked the 49th-consecutive September and the 535th-consecutive month with temperatures at least nominally above the 20th-century average. September 2023 was 0.46 °C  above the previous record from September 2020, and marks the largest positive monthly global temperature anomaly of any month on record,” said NOAA. 

The previous high anomaly was in March 2016 when the temperatures increased by 0.09°C. The past ten Septembers (2014–2023) have been the warmest ones on record. NOAA said Asia had its second-warmest September with the month being warmest in Japan. 

Hong Kong experienced 10 consecutive “very hot days”, the longest streak of such weather in the region during the month, while Pakistan had its fourth-warmest September on record.

“It was a record-warm September for Europe, Africa, North America, and South America, with Asia having the second warmest September and Australia the third warmest,” said NOAA.

It said the ongoing El Niño-dominated rainfall anomaly patterns from the eastern Indian Ocean, across the tropical Pacific, and into Central America and northern South America.

Impact on monsoon

“The South Asian monsoon was wetter than average over land, and drier to the south over the ocean, intertwined with the ENSO pattern,” it said. 

More importantly, NOAA said the January–September global surface temperature ranked highest in the 174-year record at 1.10 °C (see Table) above the 1901–2000 average of 14.1°C . This surpassed the January–September 2016 record by 0.03 °C. 

January to September was characterised by warmer-than-average conditions across much of Asia, eastern, southern, and northern North America, South America, Europe, Africa, the Arctic and Oceania. 

“Sea surface temperatures were above-average throughout most of the northern, western, and subtropical eastern Pacific, Atlantic, and Indian Oceans,” it said.

NOAA said for many continents, record heat extended back several months, increasing “evapotranspiration” which exacerbated drought in the dry areas and, in some cases, countering beneficial precipitation.

El Nino dictates

The weather continued dry over drought-plagued parts of the Indian sub-continent, the Americas, Africa, Australia, Europe, and western Russia. Asia had its fourth-warmest January–September period, said NOAA.

The US weather agency quoted the University of Maryland to say the ongoing El Niño, which emerged in June, dominated the rainfall anomaly patterns over many of the dry areas —from the eastern Indian Ocean, across the tropical Pacific and into Central America and northern South America.

NOAA said excessive warmth characterised  much of the summer, with the last 2-4 months ranking as the warmest such periods on record, continent-wide. 

Groundwater levels lower

According to the Standardized Precipitation Evapotranspiration Index (SPEI), drought plagued South-West Asia and parts of India, Russia, South-East Asia, and northern China at every time scale over the last 2 months to 4 years. 

“The lack of precipitation and high evaporation dried soils in these areas, as seen on satellite-based products, and groundwater levels were significantly lowered. Satellite observations revealed poor vegetative health from South-West Asia to northern China and Mongolia,” it said. 

According to NOAA, El Nino is expected to continue through January-March 2024, with 85 per cent chance of the weather event, which leads to drought and prolonged dry periods in Asia, extending until June.