Sentences with phrase «sahelian precipitation anomalies»

Precipitation anomalies have been stronger and covered larger areas in some earlier centuries than during the twentieth century,» according to Fredrik Charpentier Ljungqvist, historian and climate researcher at Stockholm University and lead author of this study.

As is typical, August precipitation anomalies varied significantly around the world.

As is typical, precipitation anomalies during June 2014 — August 2014 varied significantly around the world.

As is typical, precipitation anomalies during September — November 2015 varied significantly around the world.

As is typical, precipitation anomalies during November 2015 varied significantly around the world.

As is typical, precipitation anomalies during December 2015 varied significantly around the world.

The AMO has been linked to multi-year precipitation anomalies over North America, and appears to modulate ENSO teleconnections (Enfield et al., 2001; McCabe et al., 2004; Shabbar and Skinner, 2004).

As the effects of temperature anomalies on the PDSI are small compared to precipitation anomalies (Guttman, 1991), the PDSI is largely controlled by precipitation changes.

The first study explored the temporal evolution of atmospheric circulation and US precipitation anomalies during multi-year La Niña events.

Analysis showed that the AMV warming drives a modification of the Walker Circulation that creates precipitation anomalies over the whole tropical belt.

California's Blue Oaks are sensitive to changes in precipitation, and based on their tree rings scientists have reconstructed California's precipitation anomalies.

Time series of January - November precipitation anomalies in California from the historical record.

2013 year - to - date precipitation anomalies.

If they did they would show more than two small (1/8 page) graphs of simulated and observed values for temperature and precipitation anomalies (figures 9.5 a in TAR4 for temperature and 9.18 a for precipitation.

Figure 2 shows the observed precipitation anomaly (top panel), the model generated precipitation anomaly with SST forcing only (middle panel), and the model generated precipitation anomaly with the effects of observed SSTs and the added dust source (bottom panel).

Figure 2, at right: Spatial extent and magnitude of precipitation anomalies for 1932 - 1939.

Something of bigger concern locally is the precipitation anomaly chart for the next 6 months.

It is instructive to compare these numbers with those characteristic of a set of the years during 1979 — 2012 with no or only one major regional extreme event (in terms of land surface temperature and land precipitation anomalies) in the NH midlatitudes, from late April / early May to late September / early October, as reported yearly since 1993 in the World Meteorological Organization statements on the status of the global climate (see also ref.

Interannual NAO and associated SAT and precipitation anomalies.

Alaska Statewide temperature and precipitation anomalies are calculated with respect to the 1971 - 2000 base period.

Anomalies are shown in a globally complete Robinson projection, and in polar stereographic projections for the northern and southern hemispheres that do not encompass the regions of the deep tropics where precipitation anomalies are most uncertain.

Bottom row: Annual precipitation anomaly for 2017 relative to the annual average for the period 1981 - 2010.

With regard to precipitation anomalies in summer, ERA - Interim shows above average rainfall for Greece and the west of Turkey, whereas E-OBS indicates that these areas are below average.

The AMO has been linked to multi-year precipitation anomalies over North America, and appears to modulate ENSO teleconnections (Enfield et al., 2001; McCabe et al., 2004; Shabbar and Skinner, 2004).

Top row: Annual European precipitation anomalies from 1979 to 2017, relative to the annual average for the period 1981 - 2010.

Precipitation anomaly for winter, spring, summer and autumn 2017 relative to the respective seasonal average for the period 1981 - 2010.

Tree - ring records of precipitation anomalies and of temperature allowed them to reconstruct a 500 - year history of snow water equivalent in the Sierra Nevada.

The higher resolution of E-OBS shows a large positive precipitation anomaly over the Alps and the satellite soil moisture product shows above average soil moisture for a larger region than ERA - Interim.

When averaging over the whole domain, the annually averaged precipitation anomaly is small at -0.02 mm / day, just slightly below average.

Vector wind analyses were computed to explain the composite seasonal precipitation anomaly results in terms of different circulation patterns associated with these two wet groups.

Modelled isotopic anomalies clearly reflect climatic changes and, particularly in the tropics, are more regionally coherent than the precipitation anomalies.

Annual precipitation anomalies vary about zero, with relatively dry periods centered on 0.5 and 1.4 ka.»

This report discusses our current understanding of the mechanisms that link declines in Arctic sea ice cover, loss of high - latitude snow cover, changes in Arctic - region energy fluxes, atmospheric circulation patterns, and the occurrence of extreme weather events; possible implications of more severe loss of summer Arctic sea ice upon weather patterns at lower latitudes; major gaps in our understanding, and observational and / or modeling efforts that are needed to fill those gaps; and current opportunities and limitations for using Arctic sea ice predictions to assess the risk of temperature / precipitation anomalies and extreme weather events over northern continents.

It remains uncertain what role Atlantic SST anomalies play in generating the low - frequency Pacific wind response and the simulated North American precipitation anomalies in CTL.

Seasonally simulated precipitation anomalies, therefore, are very likely lower bounds on what might actually fall during the coming winter if the simulated atmospheric setup actually occurs.

We consider «moderate» temperature and precipitation anomalies to be those that exceed 0.5 SDs («0.5 SD») and «extreme» temperature and precipitation anomalies to be those that exceed 1.5 SDs («1.5 SD»).

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).

Luo L., D. Apps, S. Arcand, H. Xu, M. Pan and M. P. Hoerling (April 2017): Contribution of temperature and precipitation anomalies to the California drought during 2012 — 2015.

(D) The unconditional probability of a — 1.5 SD seasonal precipitation anomaly (blue curve) and the conditional probability that a — 1.5 SD seasonal precipitation anomaly occurs in conjunction with a 1.5 SD seasonal temperature anomaly (red curve), for each of the four 3 - mo seasons.

In addition, the probability of a — 1.5 SD precipitation anomaly increases in spring (P < 0.001) and autumn (P = 0.01) in 2006 — 2080 relative to 1920 — 2005, with spring occurrence increasing by ∼ 75 % and autumn occurrence increasing by ∼ 44 % — which represents a substantial and statistically significant increase in the risk of extremely low - precipitation events at both margins of California's wet season.

The Bottom panels (C and D) show the unconditional probability (across the ensemble) that the annual precipitation anomaly is less than — 0.5 SDs, and the conditional probability that both the annual precipitation anomaly is less than — 0.5 SDs and the temperature anomaly is greater than 0.

(C) The probability that a negative precipitation anomaly and a positive temperature anomaly equal to or exceeding a given magnitude occur in the same 12 - mo period, for all possible 12 - mo periods (using a 12 - mo running mean; see Materials and Methods), for varying severity of anomalies.

P values are shown for the difference in occurrence of — 1.5 SD precipitation anomalies between the Historical period (1920 — 2005) and the RCP8.5 period (2006 — 2080).

However, the occurrence of — 0.5 SD precipitation anomalies has not increased in recent years (40 % in 1896 — 2014 and 40 % in 1995 — 2014)(Fig. 2 A and B).

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).

This increase implies a transition to a permanent condition of ∼ 100 % risk that any negative — or extremely negative — 12 - mo precipitation anomaly is also extremely warm.

The Top panels (A and B) show the time series of ensemble — mean standardized temperature and precipitation anomalies.

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.

In addition, the number of multiyear periods in which a — 0.5 SD precipitation anomaly co-occurs with a 0.5 SD temperature anomaly more than doubles between the Historical and RCP8.5 experiments (Fig. 4A).

(A) Histogram of the frequency of occurrence of consecutive August — July 12 - mo periods in which the 12 - mo precipitation anomaly is less than — 0.5 SDs and the 12 - mo temperature anomaly is at least 0.5 SDs, in historical observations and the LENS large ensemble experiment.