Estimation of Solar Insolation and Angstrom–Prescott Coefficients Using Sunshine Hours over Nepal

Table 4

Comparison of empirical constants.

Location	Altitude masl	Empirical constant (a)	Empirical constant (b)	a + b	Remark
Tikapur, Nepalgunj	>300	0.263	0.412	0.675	Nepal
Kankai, Dharan, Dipayal	300–500	0.191	0.527	0.718
Dhunibesi, Darchula, Pulchowk, Khumaltar	1001–1400	0.258	0.417	0.675
Ilam, Okhaldhunga, Lumle	1401–1800	0.224	0.561	0.785
Jiri, Musikot, Jumla	1801–3000	0.261	0.549	0.81
South China (Guangzhou)		0.171	0.555	0.726	[15]
South-west China (Lhasa)		0.214	0.552	0.766
Jodhpur	224	0.228	0.511	0.739	[40]
Mumbai	14	0.223	0.512	0.735
Pune	560	0.229	0.531	0.76
Delhi	216	0.222	0.372	0.594	[41]
Shillong	1600	0.229	0.295	0.524
Nagpur	310	0.235	0.279	0.514
Kodaikanal	2339	0.244	0.137	0.381
Bangalore	921	0.243	0.173	0.416
Nandi Hills	1474	0.242	0.178	0.42
Bangkok		0.29	0.378	0.668	[24]
Songkhala		0.264	0.491	0.755