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The re- ice to another facility for safekeeping only a few hours earlier. MoRan, I addressed over tribal members and Freeport em- See also: ployees to explain the importance of the project to understanding local to global climate changes. After 4. Tropical glaciers, recorders and indica- ernment that allowed us to inish the drilling and take the cores tors of climate change, are disappearing globally. Annals of out of Papua Fig. So all ended well and we hope to go back Glaciology 52 59 : Diaz1 and Thomas W.

In this study we focus on the vertical proiles of climate ing are becoming manifest in the region. A number of studies variables related to both surface temperature and precipitation published over the past few decades have documented changes in changes in the Hawaiian Islands. Evidence tions from climate change projections, such as those found in the for changes on interannual time scales, such as ENSO, and lower latest Intergovernmental Panel on Climate Change Fourth frequency variations have been discussed elsewhere e.

We examined a suite of climate variables that and Chen, Our results are consistent with previous studies in showing a mean temperature, and speciic and relative humidity at standard signiicant warming trend, especially evident at higher elevations.

Statistical signiicance of the linear mountainous areas of the world. A study by Cao et al. HaleNet is a network of climate monitoring stations, both sites in most months. The irst three sta- 0. The TWI is a tions were installed along the leeward transect in A recent study of projected changes in tions in surface temperature relate to free-atmosphere values. The 1 Excerpted from Diaz, H. Giambelluca, and J. Analysis Figure 1 gives the total linear trend change over the period at each standard pressure level for mean temperature.

For a more complete set of igures and a summary table of the trends, see Diaz et al. Greater warming at the higher elevations agrees well with the indings of GDL, who found that surface warm- ing was enhanced at the higher elevation stations. A number of studies have examined relative changes in surface and free air temperature, with an eye toward elucidating inter alia possible differences between the long-term records at surface sites and the shorter upper air record Seidel and Free, ; Pepin and Norris, ; Pepin and Seidel, While in many instances tempera- ture changes at higher surface elevations are consistent with those derived from those at nearby upper air stations, in other instances Figure 1.

Total linear trend change for the period — in mean annual tem- this agreement was lacking. Values were calculated in two ways: one using the time series of annual values at each level red lines , and second using pentad averages to smooth the We note that surface temperature data from two long-term high variability and extract a more robust estimate orange curves.

Since the occurrence The apparent peak warming rate at mb, may relect the ob- of freezing temperatures on the higher slopes of Maui and the served increase in the frequency of occurrence of the trade wind Big Island is ecologically signiicant, we compared the frequency inversion Cao, ; Cao et al.

The results, shown in Figure 3 base height and the original inversion top height. The ied with elevation as a result of greenhouse warming IPCC, radiosonde data from Hilo indicate a signiicant decrease in the Trend in annual mean height meters of the freezing level isotherm over Figure 3. Thick line gives the 5-year running mean.

Thick line gives the 5-year running means. Sea surface temperature an open question Diaz and Bradley, ; Lu et al. The base of the TWI varies seasonally with an important from the point of view of ecosystem impacts, but that average inversion base height of — m, or between the may also inluence societal concerns such as those related to wa- and hPa standard pressure levels plotted in Figure 1.

The ter resources. Our results are consistent with previous studies in inversion top—the level at which the temperature resumes de- showing a signiicant warming trend, especially evident at higher creasing with height—is generally below the hPa level Cao, elevations. In particular, we document a decrease in the frequency ; Cao et al. In Diaz et al. The temporal changes are dominated by ENSO vari- ment with analogous studies done for other mountainous areas of ability and the secular trend, which is also conlated with decadal the world.

The thermodynamic changes indicated in Figures 1 and 6 of Diaz et al. In the Mitas and Clement studies discrepancies were examined between the strength of the Hadley Circulation ob- tained from the suite of available Reanalysis products and results derived from the 20th century coupled simulations forced with Figure 4. Mean annual values shown by thick line. Data courtesy of Paul Jokiel. Reference additional external forcings such as sulfate aerosols, volcanic source: Jokiel and Brown Eischeid, C.

Duncan, and R. Our goal was to reproduce Variability of freezing levels, melting season indicators, and the vertical changes in temperature, RH, and SHUM ield using snow cover for selected high-elevation and continental regions vertical proile data from these two sites.

However, we concluded in the last 50 years, Climatic Change, 59, 33— Therefore, we are unable to present an Changes in the vertical proiles of mean temperature and hu- analysis of changes in the vertical humidity proile based on the midity in the Hawaiian Islands. Nevertheless, our overall indings are strongly 77, 21—25 suggestive of warming throughout the lower troposphere in the region of the Hawaiian Islands leading to lower frequency Giambelluca, T.

Diaz, and M. Press, Cambridge, U. Global warming, regional warming trend and a possible enhancement of the regional me- trends and inshore environmental conditions inluence coral ridional Hadley circulation.

Kistler, R. Keimig, H. Diaz, and D. Dool, H. Kruk, M. Evaluating the impacts of Cao, G. Local Storms, Savannah, GA. Cao, G. Giambelluca, D.

Stevens, and T. Loope, L. Vulnerability of island Inversion variability in the Hawaiian trade wind regime, tropical montane cloud forests to climate change, with special J. Chu, P. Interannual and interdecadal Lu J. Vecchi, and T. Expansion of the rainfall variations in the Hawaiian Islands, J.

L, doi Diaz, H. Bradley eds. The Hadley Circula- Mitas, C. Has the Hadley cell been tion: Present, Past and Future. Dordrecht: Kluwer Academic strengthening in recent decades? Recent changes in tropi- Mitas, C. Recent behavior of cal freezing heights and the role of sea surface temperature. Wigley, J. Boyle, D. Gaffen, J. Hnilo, D. Nychka, D. Parker, and K. Statistical signiicance of trends and trend differences in layer- Pepin, N.

An examination of the average atmospheric temperature time series. Comparison of lower-tropo- doi Pepin, N. A global comparison of surface and free-air temperatures at high elevations, J. Geo- Timm, O. Synoptic-statistical approach phys. Quan, X. Change in Clim. Dordrecht: Kluwer Academic Publishers, 85— Civil Environ. However, long-term monitoring shows that 1 Secchi depth transparency has declined by 10 m since , 2 the rate of 14C primary productivity continues to increase at about 5 percent per year, and 3 thick growths of attached algae cover portions of the once-pristine shoreline Goldman et al.

Additionally, like many lakes world-wide, Lake Tahoe has been affected by non-native species that were either intentionally introduced or were part of a large pattern of regional invasion Kamarath et al. Figure 2 lists some additional basic facts about the Figure 1. Environmental statistics about Lake Tahoe. The latter ind- well as loss of oxygenated habitat for salmonids. The hydrology data were also used in a stormwater routing and water Figure 3.

Figure 3 shows the information low in the study design. Estimated changes in flood frequency for the Upper Truckee River for rain-on-snow events decline Fig.

From to , the Tahoe basin contributed on average 23 percent ranging from percent of the annual yield of the Truckee River at Farad, near the CA-NV border. In 20 out of the last years, however, the lake level has fallen below the natural rim.

If climate change increases the frequency or persistence of levels below the rim, the consequences for water supply in the Truckee River basin could be severe. We used the 21st Century down-scaled Figure 5. Modeled annual minimum Palmer Drought Severity Index at two sta- temperature and precipitation daily output from two General tions for two scenarios in the Tahoe Basin. Without complete ventilation, dis- 10 solved oxygen will be lost from the mid-deep water column with 5 the release of nutrients from the anoxic bottom sediments Figs.

Release of soluble reactive phosphorus from the bed of Lake Tahoe for impacts of climate change on nutrient and sediment loading from two emission scenarios, based on results from GFDL climate model and the Lake urban runoff can be offset by aggressive implementation of BMPs. Clarity Model. Simulated level of Lake Tahoe over the 21st Century, for two emission scenarios. Downscaling and sediment lux to the lake including BMP implementation with Constructed Analogues: Daily Precipitation and Tempera- and erosion control , and increased water conservation efforts in ture Fields Over the United States.

California ClimateChange the Truckee River basin. Report no. Aquatic CR. The Warming of Lake Tahoe. Climatic Change Invasions 3: Coats R. Climate change in the Tahoe basin: regional Riverson J. Projected low nutrient and sediment loads trends, impacts and drivers Climatic Change Pages Davis, CA. Water Resour. Davis, doi CA: Univ. Tahoe Environ.

Tague, and G. E Grant. Vulnerability of paper demonstrates that for basins across the Western Cordillera water supply from the Oregon Cascades to changing climate: of the US, spatial differences in drainage rates and groundwater Linking science to users and policy.

Global Environmental response times associated with geologic and geomorphic settings Change, In Tague and Grant we used a conceptual mathematical In the past decade, empirical observations and hydrologic models model to develop a general relationship among changes in water have shown that one of the primary climate warming impacts on inputs either as snowmelt or precipitation, subsurface drainage streamlow is through changes in the spatial and temporal pat- eficiency, and summer streamlow responses.

Application of this terns of snow accumulation and melt Bales et al. The timing of snowmelt controls when months. Reduced snow accumulation and earlier melt have been shown to decrease summer water availability for human water users and both aquatic and terrestrial ecosystems Rood et al. At the same time changes in precipitation patterns, includ- ing increases in intensity and frequency of drought, have the potential to compound these effects Luce and Holden As the climate continues to warm, resource managers need accurate predictions of these effects across a range of scales.

While the general relationships among warming, snowmelt and streamlow are understood, a key challenge is providing assessments at local watershed scales relevant to resource decisions. Spatial patterns of sensitivity of snow accumulation and melt re- lect topographic complexity of mountain environments.

In Tague and Grant , we showed that spa- tial patterns of streamlow response to warming relect not only sensitivity to changes in snow accumulation and melt but also Figure 1. Mean daily discharge for September against annual maximum day running average of mean watershed snow water equivalent depth SWE.

From Tague and Grant Environmental characteristics of the study regions. We The implication of these differences can be seen by applying a then applied a spatially distributed hydrology model, RHESSys similar 1. Paradoxi- Regional hydro-ecologic simulation system , to four watersheds cally, our results show that slower draining, deep groundwater that differ in terms of both geologic characteristics and snowmelt dominated watersheds are likely to have more water in summer patterns Table 1 We used the model to compare changes in but subject to the greatest absolute summer water losses under September streamlow as a function of annual peak snow-water a 1.

A slow draining watershed equivalent SWE , spatially averaged across the watershed Fig. As expected, all watersheds showed increases in late summer the summer streamlow reduction with a 1.

Fast-draining water- perature, when compared with faster draining watersheds with sheds, such as those underlain by granite in the California Sierras similar timing of peak snowmelt. The faster draining watersheds, or deeply dissected volcanics in the western Cascades of Oregon, in contrast, have greater reductions in spring low.

Our results however, showed less sensitivity to inter-annual variation in peak highlight the importance of geological factors in interpreting hy- SWE relative to slower draining, deeper groundwater dominated drologic response to climate change, and argue for a geo-climatic systems such as the Oregon High Cascades.

Our results assessing climate change impacts in mountain regions throughout show that it is the combination of the timing of snowmelt and the the globe. Institutions within some sectors were deeper groundwater-dominated High Cascades and more respon- found to be better positioned to effectively respond to changes sive, shallow subsurface low-dominated Western Cascades. We in water resources, while others had substantial barriers to being conducted in-depth, semi-structured interviews with water users able to lexibly adapt to changing conditions.

For example, the and other stakeholders representing speciic water uses in the adaptability of Oregon chub is enhanced by the spatial lex- McKenzie River watershed, seeking to understand vulnerability ibility associated with its ability to establish and relocate new to changing streamlow regimes.

We presented users with model- populations within and outside the watershed. From an institu- ing results, and asked respondents to assess how changing water tional perspective, listing as part of Endangered Species Act has availability would impact their activities.

We found that vulner- supported spatially detailed analysis and thus isheries managers abilities were determined in part by the spatial scale and timing of have ability to integrate spatial distinctions in streamlow into re- water use and the lexibility of those users in time and space Fig.

Further the regulatory framework in which isheries 3. For example, in the case of ish habitat for endangered spe- conservation occurs supports periodic review and facilitates the cies, bull trout currently rely on the colder refuguia of the High integration of new scenarios as they become available. Cascade system, which is commonly perceived by some isheries managers as more stable and less sensitive to climate change.

This lexibility is in contrast to the institutional constraints that Our hydrologic modeling results, however, suggest that summer the U. Army Corps of Engineers, which manages the two main streamlow in these systems will actually show greater losses reservoirs in the McKenzie watershed, operate under. The strategic importance of the High Cascade region on estimates of lood risk that were developed years ago Figure 2. RHESSys estimates of change in average day of year flow between baseline and 1.

Mean unit discharge is computed by averaging RHESSys estimates of daily streamflow normalized by drainage area for each day of year for 30 year climate record. Assessing sensitivity and adaptability, including factors related to response capacity of water users with respect to climate change effects on streamflow in the McKenzie River watershed.

From Farley et al. Our interviews with managers underscore a years. Because the rule curves are Congressionally authorized, broad need across many water resource sectors for spatially ex- any change in these rules requires a detailed evaluation of the hy- plicit information and prediction across a range of scales on how drologic, economic, and environmental tradeoffs of any proposed streamlow regimes are likely to change in the future.

Hamlet, and D. Impli- system that includes 13 major reservoirs and multiple demands cations of global climate change for snowmelt hydrology in the and rule curves. While the Corps recognizes the need to adapt to twenty-irst century.

Hydrological Processes 23 7 : Even for smaller-scale water managers, such Bales, R. P Molotch, T. H Painter, M. D Dettinger, R. Mountain hydrology of the western tional lexibility, the time and costs associated with infrastructural United States.

Water Resources Research 42 8 : Adam, and D. Potential are tailored to spatial differences in streamlow responses to impacts of a warming climate on water availability in snow- warming. Nature November 17 : In summary, we are learning that a combination of both geologi- Changes in the timing of snowmelt and evaluating watershed sensitivity to streamlow changes at scales streamlow in Colorado: a response to recent warming.

Journal relevant for water resource managers. Geologically-mediated of Climate 23 9 : — One of the key chal- Kapnick, S. Causes of recent changes in lenges to incorporating this insight into water resource planning western North American snowpack. Climate Dynamics: 1— Declining annual stream- streamlows. This is a problem because many watersheds of low distributions in the Paciic Northwest United States, interest to water and isheries managers are ungaged or have short — Geophysical Research Letters 36 6.

In these cases, strategies to infer Maurer, E. Uncertainty in hydrologic impacts of climate drainage eficiency directly from mapped geology are needed; change in the Sierra Nevada, California, under two emis- we are working on this now.

Climatic Change 82 3 June 1 : Cayan, and M. D Dettinger. Changes in the Paciic Northwest. Journal of Hydrometeorology 7 5 toward earlier streamlow timing across western North Ameri- October 1 : Journal of Climate 18 8 : — Rood, S. Pan, K. M Gill, C. G Franks, G. M Samuelson, Tague, C. Groundwater dynamics medi- and A. Declining summer lows of Rocky ate low-low response to global warming in snow-dominated Mountain rivers: Changing seasonal hydrology and probable alpine regions.

Water Resources Research, W Journal of Hydrology : — Zielinski, and E. Journal of Wildlife Management, The Important Role of Predators in Ecosystems Predators have important effects on the structure of biological communities, not only because the act of killing and eating other species transfers energy and nutrients but also because their consumption of prey, and their simple presence, affect the dis- tribution of herbivores which, in turn, affect the abundance and distribution of plants.

An American marten Martes americana photographed at a baited mammalian predators and to collect information that will help chicken and remotely triggered camera station in the Sierra Nevada of California. California has already lost some key mammalian predators i.

Thus, the disproportionately important Distribuion functional roles of mammalian predators are already reduced in montane forest ecosystems in California, and elsewhere in North Some of our recent work has focused on the distributional dy- America Laliberte and Ripple We focus our research on namics of the marten Fig. The highest density of detections was located in the largest protected area in the region, Lassen Volcanic National Park. This is in stark con- trast to the historical distribution, which found that martens were evenly distributed in the region during the early s, including at lower elevation sites Fig.

Records 5 - 10 11 - 20 21 - 30 Over 30 N 0 25 50 75 kilometers Figure 2. Distribution of historical records Grinnell et al. Bold lines represent the boundaries of the historical distribution as represented in Grinnell et al.

Black dots in the historical map represent one or more records depending on size. Black dots in the contemporary map represent one or more track plate or camera stations per sample unit depending on size where a marten was detected — ; open circles represent sample units with no detections. Concern about the decreasing distribution of martens in some regions of the Paciic states has been voiced for decades Dixon , Kucera et al.

Historical and contemporary distributions were formally com- pared in the Sierra and Cascades of California by contrasting the locations of animals trapped for their fur in the early s Grin- nell et al.

These surveys revealed changes in the distributions of a number of carnivore species, in- cluding the marten, isher, wolverine and Sierra Nevada red fox. Historically, the marten was reported to occur throughout the higher elevations of this region but our survey results indicated that populations are now reduced in size and fragmented Fig.

Figure 3. Predicted probability surface of top performing model with detection results for American martens in northeastern California. Inset depicts the region where independent test data were available. Historical B. Contemporary Cascades as a whole. Perhaps, we thought, the type of changes Marten Marten that occurred at SEF, when aggregated over the larger region, ac- Records Detecions Naional Forest Survey Locaions counted for the larger changes seen in the earlier regional work?

However, GIS analysis comparing older vegetation maps from Boundaries Reserves with maps from revealed a loss and fragmentation of important marten habitat Moriarty et al. This included a decrease in predicted habitat patch size, core area, and total amount of marten habitat in the study area, as well as an increase in distance between important habitat patches. The sensitivity of martens to forest fragmentation is well established e. Northeastern California, primarily the Cascades mountains in Cali- Potvin et al.

As a result of this , national forest boundaries thin lines and the reserves as of i. The bold lines indicate improve habitat quality for martens and that this same approach the boundaries of the historical distribution of martens Grinnell et al. The Cause? The change in marten distribution at SEF occurred rapidly; more The loss of marten distribution seems clear, but what is less clear rapidly than changes in the lora and fauna that affect martens is the cause.

This is dificult to ascertain with data from such a might be expected to change due to climate. Yet, marten is a large region; what is necessary instead is a more focused look species that may not fare well given the predicted changes in at a smaller area that may have experienced a loss of martens vegetation distribution as a result of warming climates.

The true over this same period and to ask what may have caused the loss ir Abies sp. This is where our recent work in the Sagehen Experi- ish in area Lenihan et al. Thus, marten Moriarty et al. SEF has hosted a number of seminal populations have experienced rapid changes in their habitat as studies on marten ecology in California, but the unique element a result of timber harvest and may experience additional loss of of this body of work is that most of these studies also included a habitat with climate change.

Martens were assumed to samples collected from the northern Sierra and southern Cascades be very common in the SEF in the s and s but anecdotal in the early s with samples we have collected recently. This observations suggested that they had become quite rare at SEF. We hope that other public land managers will follow this lead and consider marten habitat in future management plans. Also encouraging is the creation, by the Lassen NF, of a marten habitat connectivity plan Kirk and Zielinski Second, in February a wolverine was veri- ied to occur on the Tahoe NF, the irst veriied record of this species in California in over 80 years Fig.

Genetic tests indicated that it had a high likelihood of originating from the wolverine population in Idaho Moriarty et al. Then, in August of , biologists who were conduct- ing camera surveys for another purpose were amazed to have photographed a red fox near Sonora Pass in the central Sierra Nevada, which was later veriied from a genetic sample to be a Sierra Nevada red fox B. Sacks, UC-Davis, unpubl.

Since then at least three additional individual foxes have been photographed by biologists S. Rich, Stanislaus National Forest, C. Stermer, California Fish and Game, pers. As exciting as the discovery of a second population of Sierra Nevada red foxes, is the recent news that these individuals are a remnant of a population that originally occurred in the southern Sierra Nevada, genetically distinct from the small population at LVNP B.

Restoration of populations of the montane carnivores of California will require coordinated effort by managers, conservationists and the public. We will require new science that identiies important habitat and plans for Figure 5.

American marten Martes americana detections in, and immediately north of, the Sagehen Experimental Forest, California during 9 previous surveys Spencer , Zielin- maintaining connections among habitat patches, now ski , Martin , and during 3 surveys in — Moriarty et al. However, recent Stations with and without marten detections are indicated by large and small solid circles, respectively. Dixon, and J.

Fur-bearing mammals of California. University of California Press, Berke- ley. Hargis, C. Bissonette, and D. The in- luence of forest fragmentation and landscape pattern on Ameri- can martens. Journal of Applied Ecology Kirk, T. Developing and testing a landscape habitat suitability model for the American marten Martes americana in the Cascades mountains of California.

Landscape Ecology Modeling functional hab- itat connectivity of the American marten Martes americana Figure 6. Initial photograph of the male wolverine Gulo gulo that was pho- tographed at a remote camera station in February on the Tahoe National in northeastern California using least-cost corridors.

Report to Forest in the Sierra Nevada of California. This was the first verifiable evidence of the Lassen National Forest. The camera was part of a grid of similar cameras set to document the occurrence of American marten Martes tion, Arcata, California. Kucera, T. Zielinski, and R. The cur- the species themselves as they demonstrate their extraordinary rent distribution of American marten in California.

California abilities to disperse to suitable habitat or unexpectedly reveal Fish and Game Our Laliberte, A. Range contractions of efforts, combined with their characteristics, will help maintain North American carnivores and ungulates. Bioscience mammalian carnivores and the important functions they contrib- Lawler, J. Safford and E. In press. Mar- References tens and ishers in a changing climate.

In Aubry, K. Bissonette, J. Fredrickson, and B. Zielinski, M. Raphael, G. Proulx, and S. Buskirk, editors. American marten: a case for landscape-level management. Resources Conference, pages Washington, D. Lenihan, J. Brown, R. Spalding, D. ReVelle, E. Tagliaferri, S. Worden, Nature , The Kamil Crater in Egypt 2. Bland, N. Artemieva, Meteorit. Earth Impact Database, www. Press, Oxford, Antonio Zeoli,1 Ali M. Collins, H. Melosh, R. Marcus, Meteorit.

Aly A. Folco, Geostand. Artemieva, Nature , Herd et al. Hussein and F. Porcelli provided diplomatic support; the Egyptian Army, logistical support; G. Negro, field assistance; small craters on Earth occur on decadal to secular atic searches SOM. Speranza and P. Rochette, helpful discussion; the time scales 1, 2. However, small craters are rare nel produced by the explosion of the impactor upon European Commission Marie Curie Actions—RTNs on Earth because they are rapidly eroded, and hypervelocity collision with the target Fig.