Sentences with phrase «observed changes in precipitation»

Observed changes in precipitation and aspects of surface hydrology are described in more detail by Trenberth et al. (2007), Section 3.3.

«What causes the observed changes in precipitation and temperature is not something we have addressed because of the difficulties in doing so just based on observational records,» Villarini says.

Not exact matches

Attributable human - induced changes in the likelihood and magnitude of the observed extreme precipitation during Hurricane Harvey.

To see how increased temperatures might contribute to the reductions in the river's flow that have been observed since 2000, Udall and Overpeck reviewed and synthesized 25 years of research about how climate and climate change have and will affect the region and how temperature and precipitation affect the river's flows.

The changes shown in these maps compare an average of the model projections to the average temperature and precipitation benchmarks observed from 1971 - 2000.

However, the simulations indicate that the sea - ice driven precipitation changes resemble the global rainfall patterns observed during that drought, leaving the possibility that Arctic sea - ice loss could have played a role in the recent drought.

«Observing rainfall in an El Niño year is especially interesting because the prevailing precipitation patterns change, often in extreme ways.

The westerlies in the Northern Hemisphere, which increased from the 1960s to the 1990s but which have since returned to about normal as part of NAO and NAM changes, alter the flow from oceans to continents and are a major cause of the observed changes in winter storm tracks and related patterns of precipitation and temperature anomalies, especially over Europe.

This is addressed by evaluating change in global or large - scale patterns in the frequency or intensity of extremes (e.g., observed widespread intensification of precipitation extremes attributed to human influence, increase in frequency and intensity of hot extremes) and by event attribution methods.

In part because of large intrinsic variability, no evidence was found for changes in extreme precipitation attributable to climate change in the available observed record.&raquIn part because of large intrinsic variability, no evidence was found for changes in extreme precipitation attributable to climate change in the available observed record.&raquin extreme precipitation attributable to climate change in the available observed record.&raquin the available observed record.»

These results are based on a comparison of observed and multi-model simulated changes in extreme precipitation over the latter half of the twentieth century analyzed with an optimal fingerprinting technique.

Changes in extreme precipitation projected by models, and thus the impacts of future changes in extreme precipitation, may be underestimated because models seem to underestimate the observed increase in heavy precipitation with wChanges in extreme precipitation projected by models, and thus the impacts of future changes in extreme precipitation, may be underestimated because models seem to underestimate the observed increase in heavy precipitation with wchanges in extreme precipitation, may be underestimated because models seem to underestimate the observed increase in heavy precipitation with warming.

Visible changes in hydrological cycle have been observed in the form of changing precipitation patterns, cropping patterns, droughts, water availability periods, frequency and intensity of heatwaves, precipitation events and weather - induced natural disasters.

Joseph Bast, who works with the group, highlighted some of the group's conclusions in Forbes: There is little risk of global food insecurity owing to higher levels of CO2, as higher CO2 will greatly aid plant productivity; «No changes in precipitation patterns, snow, monsoons, or river flows that might be considered harmful to human well - being or plants or wildlife have been observed that could be attributed to rising CO2»; and little risk to aquatic or dry - land ecosystems.

Before we accept AGW there is a lot more work to be done to exclude natural variability as the explanation for the observed changes in temperature and precipitation.

Osborne, J. M., Lambert, H. Groenendijk, M., Harper, A.B., Koven, C.D., Poulter, B., Pugh, T.A.M., Sitch, S., Stocker, B.D., Wiltshire, A. and Zaehle, S. 2015: Reconciling precipitation with runoff: observed hydrological change in the midlatitudes.

For the entire Northern Hemisphere, there is evidence of an increase in both storm frequency and intensity during the cold season since 1950,1 with storm tracks having shifted slightly towards the poles.2, 3 Extremely heavy snowstorms increased in number during the last century in northern and eastern parts of the United States, but have been less frequent since 2000.11,15 Total seasonal snowfall has generally decreased in southern and some western areas, 16 increased in the northern Great Plains and Great Lakes region, 16,17 and not changed in other areas, such as the Sierra Nevada, although snow is melting earlier in the year and more precipitation is falling as rain versus snow.18 Very snowy winters have generally been decreasing in frequency in most regions over the last 10 to 20 years, although the Northeast has been seeing a normal number of such winters.19 Heavier - than - normal snowfalls recently observed in the Midwest and Northeast U.S. in some years, with little snow in other years, are consistent with indications of increased blocking (a large scale pressure pattern with little or no movement) of the wintertime circulation of the Northern Hemisphere.5 However, conclusions about trends in blocking have been found to depend on the method of analysis, 6 so the assessment and attribution of trends in blocking remains an active research area.

The observed global greening has occurred in spite of all the many real and imagined assaults on Earth's vegetation that have occurred over the past several decades, including wildfires, disease, pest outbreaks, deforestation, and climatic changes in temperature and precipitation, more than compensating for any of the negative effects these phenomena may have had on the global biosphere.

Although there is as yet no convincing evidence in the observed record of changes in tropical cyclone behaviour, a synthesis of the recent model results indicates that, for the future warmer climate, tropical cyclones will show increased peak wind speed and increased mean and peak precipitation intensities.

[2] Bhend J, Whetton P (2013) Consistency of simulated and observed regional changes in temperature, sea level pressure and precipitation.

When I found that changes in observed precipitation were largest in autumn, and did not find the same patterns of precipitation in climate models outputs, I really became skeptical about the use of climate models.

We conclude by underlining that the observed variation of glacier surface and SLA changes could be explained by the increase of temperature and decrease of precipitation in recent years.

Hoerling: «We can also say with high confidence that no appreciable trend toward either wetter or drier conditions has been observed for statewide average precipitation since 1895» — «At present, the scientific evidence does not support an argument that the drought there is appreciably linked to human - induced climate change... In short, the drought gripping California has been observed before.

Observed changes in short term precipitation intensity from previous research and the anticipated changes in flood frequency and magnitude expected due to enhanced greenhouse forcing are not generally evident at this time over large portions of the United States for several different measures of flood flows.

Ozone depletion in the late twentieth century was the primary driver of the observed poleward shift of the jet during summer, which has been linked to changes in tropospheric and surface temperatures, clouds and cloud radiative effects, and precipitation at both middle and low latitudes.

With wNA forest loss, there are significant declines in both precipitation and temperature during the early growing season, however it is the change in the relative humidity that dominates the observed increase in VPD.

I conclude that the observed global aridity changes up to 2010 are consistent with model predictions, which suggest severe and widespread droughts in the next 30 — 90 years over many land areas resulting from either decreased precipitation and / or increased evaporation.

Average precipitation is changing in many regions with both increases and decreases and there is a general tendency for increases in extreme precipitation observed over land areas.

The impacts of climate change on freshwater systems and their management are mainly due to the observed and projected increases in temperature, sea level and precipitation variability (very high confidence).

The widespread trend of increasing heavy downpours is expected to continue, with precipitation becoming less frequent but more intense.13, 14,15,16 The patterns of the projected changes of precipitation do not contain the spatial details that characterize observed precipitation, especially in mountainous terrain, because the projections are averages from multiple models and because the effective resolution of global climate models is roughly 100 - 200 miles.

Rigorous analyses have shown that natural variability alone can not explain the observed long - term trends of changing extremes in temperature and precipitation.12

Changing distributions of temperature, precipitation, and carbon dioxide could affect the potency of plant allergens, 43 and there has been an observed increase of 13 to 27 days in the ragweed pollen season at latitudes above 44 ° N. 43

CAS = Commission for Atmospheric Sciences CMDP = Climate Metrics and Diagnostic Panel CMIP = Coupled Model Intercomparison Project DAOS = Working Group on Data Assimilation and Observing Systems GASS = Global Atmospheric System Studies panel GEWEX = Global Energy and Water Cycle Experiment GLASS = Global Land - Atmosphere System Studies panel GOV = Global Ocean Data Assimilation Experiment (GODAE) Ocean View JWGFVR = Joint Working Group on Forecast Verification Research MJO - TF = Madden - Julian Oscillation Task Force PDEF = Working Group on Predictability, Dynamics and Ensemble Forecasting PPP = Polar Prediction Project QPF = Quantitative precipitation forecast S2S = Subseasonal to Seasonal Prediction Project SPARC = Stratospheric Processes and their Role in Climate TC = Tropical cyclone WCRP = World Climate Research Programme WCRP Grand Science Challenges • Climate Extremes • Clouds, Circulation and Climate Sensitivity • Melting Ice and Global Consequences • Regional Sea - Ice Change and Coastal Impacts • Water Availability WCRP JSC = Joint Scientific Committee WGCM = Working Group on Coupled Modelling WGSIP = Working Group on Subseasonal to Interdecadal Prediction WWRP = World Weather Research Programme YOPP = Year of Polar Prediction

Other factors for the observed 7 percent increase in runoff from 1936 to 1999 could be changes in ice and permafrost melt or changes in the seasonality of precipitation and runoff, he said.

They looked at the observed behavior within latitude bands in which the modeled precipitation changes were more or less of the same character.

Obviously, climate models whose hindcasts differ in sign from what is observed (Zhang et al., 2007), or which indicate that human influences are indistinguishable from natural changes (Sarojini et al., 2012) possess no skill in identifying a human - induced climate signal on observed precipitation across the U.S. and therefore should not be used to make future projections.

The first paper cited notes (caveating that observational uncertainties are considerable) that models do not match observed changes in subtropical relative humidity or in global precipitation.

Changes in some types of extreme events have already been observed, for example, increases in the frequency and intensity of heat waves and heavy precipitation events (see FAQ 3.3).

While surface temperature show a significant warming over western Himalayas in the last few decades, the observed regional precipitation changes are irregular and not spatially coherent.

She continues by observing that «it is likely that both extreme weather events (storms, floods, heat waves) and changes in mean temperatures, precipitation and sea - levels will in many cases contribute to increasing levels of mobility.»

«We show that anthropogenic forcing has had a detectable influence on observed changes in average precipitation within latitudinal bands, and that these changes can not be explained by internal climate variability or natural forcing.

Anthropogenic influences have contributed to observed increases in atmospheric moisture content in the atmosphere (medium confidence), to global - scale changes in precipitation patterns over land (medium confidence), to intensification of heavy precipitation over land regions where data are sufficient (medium confidence), and to changes in surface and subsurface ocean salinity (very likely).

[10] Observed trends in precipitation and floods over Europe are in line with these future projections, however their climate change signal is quite complex.

«With an early arrival of monsoon - like atmospheric circulation in June, the heavy precipitation that occurred in northern India was a once - in - a-century event; however, analyses of observed and simulated June precipitation provide evidence that human - caused climate change has increased the likelihood of such an event.»

Observed changes in regional temperature and precipitation can often be physically related to one another.