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Abstract

Abstract. Erica Lindgren PO Box 462 Bethlehem, NH 03574 ehl4@cisunix.unh.edu

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Abstract

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  1. Abstract • Erica Lindgren • PO Box 462 Bethlehem, NH 03574 • ehl4@cisunix.unh.edu The western tropical Pacific region is a hot spot of interest for today’s atmospheric scientists, but how much do we truly know? Previously unprocessed data from the island of New Guinea has allowed insight into the area’s climate change with trends that only partially agree with those determined by others. To look into the climate change in this region, radiosondes, MSU and OLR satellite data, surface data from elevations up to 3800 m, NCEP Reanalyses, and EOF analysis were used. Through these new datasets, warming in the lower troposphere over New Guinea was found to be possibly more significant than surface warming. Several different time periods were analyzed due to dataset discontinuities with the following general trends noted. From the 1950s to present, warming occurred at both the surface and in the lower troposphere. From 1979 to present, warming was found at surface whereas cooling was found in the lower troposphere. Finally, from 1994 to present, both the surface and the lower troposphere warmed, but the warming increased with altitude. These results show that choice of study interval significantly influences the resulting trends due to significant decadal fluctuations. The discrepancies that we see between sparse New Guinea data and surrounding warm-pool data imply that atmospheric features over New Guinea, likely related to the ITCZ, may be important in understanding tropospheric change in this region.

  2. New Guinea’s Climate Regime Change Insurgent Temperatures recruit more to their cause

  3. Where in the World is New Guinea? q

  4. S S S Surveyed Site S S S S S S S S S

  5. Why New Guinea New Guinea’s land area is less than 0.3% of the world's surface area, but is: • considered one of the world's mega-diversity hotspots • a storehouse for nearly five percent of the world’s biological diversity • Home to over 200 threatened species • largest and highest tropical island in the world • the largest tropical rain forest after the Amazon and the Congo • 11,000 species of plants, about 60 percent of which are endemic

  6. Importance of New Guinea • New Guinea weather largely reflects that of the west Pacific warm-pool • Influential in tropical weather and El Nino Southern Oscillation (ENSO) • Warm pool is greatest source of energy to global atmosphere, area of greatest convection, therefore strong influence on global weather Good Fellow’s Tree Kangaroo

  7. Importance of New Guinea • Island adjacent to Warm Pool • Great topographic range • Extended record puts shorter satellite record in perspective and tests shorter trends Tenkile

  8. Problem • Controversy concerning lower tropospheric temperature change especially in tropics. • Most say temp of lower trop did NOT warm for 1979-2002 as much as surface temps warmed. • What is the temp record in New Guinea and why? Black-Spotted Cuscus

  9. Methods • Several datasets were used including: • Radiosondes • MSU data • OLR • Surface Data • NCEP Reanalysis • Empirical Orthogonal Function (Factor Analysis) Alpine Wallaby

  10. Radiosondes • Weather balloons collect information as they rise into the atmosphere • Allows for vertical information • Problems : Change of instrumentation over the years, same calibration? • Time range: 1957 to present

  11. Satellites- MSU and OLR • MSU = microwave satellite unit • Observes temperatures in higher atmosphere • Problems: Interference between stratospheric vvand lower troposphere temperature affects • OLR = Outgoing long wave radiation • Measures cloud coverage in upper vvvtroposphere • Time Range: 1970’s-Present

  12. NCEP • Climate model based off of radiosonde data, satellite data, and other available data sets. • Three dimensional picture of the atmosphere, a complete description • Problems: Low resolution, suspect before 1967 (data sets mishandled) • Time Range: 1948-Present Northern Glider

  13. Surface • Surface data records contain rain and temperature data. Some have more extensive records and include humidity, dew point, wind direction and wind strength • Problems: Equipment changes, keeping stations running • Time range: 1916- Present Ground Cuscus

  14. Empirical Orthogonal Function • EOF’s have been run on a variety of datasets • Searched for signals that explain variance in different records • Gives an idea of what is affecting these records, allowing for correlation among many records Victoria Crowned Pidgeon

  15. Results • New Guinea climate is representative of wider area. • EOF 1 of NCEP Reanalysis temperature at different levels explaines 90% of variance in records. • Multi-decadal series • Non-ENSO related Pesquet's Parrot

  16. Results Example site: Madang Record from 1940 to Present Shows warming trend

  17. Surface Stations 1955-1974 1979-2003 1994-2003 1994- 2003: Warming increases with Increasing altitude

  18. NCEP at 1000 hPa- Real Temp About 0.2 per decade

  19. Monthly Average Temp at 850 hPa around New Guinea from Radiosondes at 10N and 10S (Hadley Database) • 1973 -2002: slight warming trend • 1979 -2002: no change to slight cooling • Significant differences between temp change at 10N and at 5-10 S

  20. Source: D. Parker UK Met Office

  21. 1955- 2001 Temps in Std Pressure Layers from RAOB at Lae (red, black) and Moresby (blue,pink) New Guinea Pademelon Over the last 50 years, significant warming

  22. 1994-2004 Temps in Std Layers from RAOB at Merauke, south-central New Guinea • Warming in the last decade at different pressure levels • Warming increases with increasing altitude Long-beaked Echidna

  23. NCEP Increasing temperature trends for all levels Fly River Turtle

  24. Salvadori’s Teal MSU Shows slight warming trend in lower troposphere Others say it is cooling Our other records for this time period claim cooling More data comparison is necessary

  25. OLR • Some slight increase in clouds, but mainly no change • As temperature is increase it was expected that the clouds would increase Harpy Eagle

  26. Oceans • Warming in all equatorial oceans, most significant in the warm pool (eastern Indian ocean to western tropical Pacific) and rising 0.15 degrees a decade (taken from 1941-1991). This is comparable to our warming trends at the surface Banded Rainbow Fish Freshwater Sawfish Graceful Shark

  27. Conclusions Temp Trends: + warming –cooling • Each time period has a different trend • Temperatures trends show the troposphere and surface are coupled for 50-present and 94-present time periods • 79-present shows cooling, a discrepancy that needs further vvvvinvestigation

  28. Further Study • Whether surface stations can be used to approximate free atmosphere conditions • What is causing the change • Dynamics– we have processed other meteorological data, including water vapor and winds that will aid in understanding the dynamics of the area • Cloud convection– climate interaction

  29. Acknowledgements • Thank you to: • Michael Prentice (603)- 862-4783 • R&D Program • Austrialian Bureau of Meteorology • Dave Parker of the UK Meteorology Office • PT Freeport Indonesia Northern Glider

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