Sentences with phrase «sd drought years»

Most 1 - SD drought years have occurred when conditions were both dry (precipitation anomaly < 0) and warm (temperature anomaly > 0), including 15 of 20 1 - SD drought years during 1896 — 2014 (Fig. 2A and Fig.

Circles show the years in which the PMDI exhibited a negative anomaly exceeding — 1.0 SDs, which are referred to as 1 - SD drought years in the text.

Rather, the observed doubling of the occurrence of 1 - SD drought years has coincided with a doubling of the frequency with which a negative precipitation year produces a 1 - SD drought, with 55 % of negative precipitation years in 1995 — 2014 co-occurring with a — 1.0 SD PMDI anomaly, compared with 27 % in 1896 — 1994 (Fig. 1 A and B).

This increase in the occurrence of 1 - SD drought years has taken place without a substantial change in the probability of negative precipitation anomalies (53 % in 1896 — 2014 and 55 % in 1995 — 2014)(Figs. 1B and 2 A and B).

All 20 August — July 12 - mo periods that exhibited a — 1.0 SD PMDI anomaly also exhibited a — 0.5 SD precipitation anomaly (Fig. 1B and 2E), suggesting that moderately low precipitation is prerequisite for a 1 - SD drought year.

Not exact matches

During 1995 — 2014, 6 of the 8 moderately dry years produced 1 - SD drought (Fig. 1A), with all 6 occurring in years in which the precipitation anomaly exceeded — 0.5 SD and the temperature anomaly exceeded 0.5 SD (Fig. 1C).

For example, of the 63 negative precipitation years during 1896 — 2014, 15 of the 32 warm — dry years (47 %) produced 1 - SD drought, compared with only 5 of the 31 cool — dry years (16 %)(Fig. 2A).

We find that years with a negative PMDI anomaly exceeding — 1.0 SDs (hereafter «1 - SD drought») have occurred approximately twice as often in the past two decades as in the preceding century (six events in 1995 — 2014 = 30 % of years; 14 events in 1896 — 1994 = 14 % of years)(Fig. 1A and Fig.

For example, during 1896 — 2014, 1 - SD drought occurred in 15 of the 28 years (54 %) that exhibited both a — 0.5 SD precipitation anomaly and a positive temperature anomaly, but in only 5 of the 20 years (25 %) that exhibited a — 0.5 SD precipitation anomaly and a negative temperature anomaly (Fig. 2A).