Doldrums are characterized by

The doldrums, also known as the Intertropical Convergence Zone (ITCZ), are characterized by a belt of uniform low pressure located near the equator [c1][t6]. This region is formed where the trade winds from the Northern and Southern Hemispheres converge [c1][t2]. Due to intense solar heating, the air in this zone expands and rises through convection, creating a permanent low-pressure trough [c2][t6]. Because the air movement is primarily vertical, surface winds are extremely light, weak, or absent, leading to the 'calm' conditions for which the belt is famous [c3][t4]. While the region is associated with high humidity and heavy precipitation due to moisture-laden trade winds and convective cloud formation [c3][t6], the defining pressure characteristic is its uniform low pressure rather than high pressure or high wind velocity [c1][c2].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Equatorial Low-Pressure Belt or 'Doldrums' > p. 311
2. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 14: Climate > Pressure and Planetary Winds > p. 139
3. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > Climate > p. 312
4. [4] https://education.nationalgeographic.org/resource/wind/
5. [5] https://www.sciencedirect.com/topics/earth-and-planetary-sciences/intertropical-convergent-zone