Raytheon Polar Services Company UNITED STATES ANTARCTIC PROGRAM 2004 AWS-AMRC-AMPS Annual Joint Meeting - Charleston, SC South Pole Meteorology Kathie Hill 9 June 2004 Raytheon Polar Services Company Denver, Colorado Photo: Kris Perry, South Pole winter over Meteorologist

Advancing Polar Science Raytheon Polar Services Company We will discuss……. Objectives of the South Pole Meteorology department South Pole Met support and data integrity issues Implemented upgrades and those to come Comparison study and planned switch over to new Met system

Advancing Polar Science Raytheon Polar Services Company South Pole Meteorology Department Objectives Support –Aviation –Station Ops –Science –Antarctic Forecasting –47 Year Data Record –Annual race around the world

Advancing Polar Science Raytheon Polar Services Company Contributing Factors to Inconsistencies in the South Pole Data Record Inconsistency in: –Observing practices season to season –Climatological calculations over the 47 year history Lack of documentation and tracking: –Instrument modification, replacement and performance –Station practices Improperly maintained instrumentation and software –Inability to obtain maintenance and calibration information on current instrumentation suite –Processing software modification uncontrolled

Advancing Polar Science Raytheon Polar Services Company South Pole Meteorology Improvements SPSM Met system Implementation (Jan 04) –Integrates surface data –Provides 1-minute resolution data –Desktop display of surface data –Addition of optical instruments (clouds, visibility) –Provides redundancy for winds, temps and pressure Historical data validation project (in process) –Identifying incorrect climate data –Build more consistency in historical database

Advancing Polar Science Raytheon Polar Services Company South Pole Meteorology Improvements Instrumentation tracking database (FY 05) –Provides reporting on instrument maintenance, calibration and performance to researchers –Ensures maintenance and calibration schedules are maintained Station observer practices defined and documented (FY 04) –Builds consistency in surface data season to season DIGI-Cora III Upper Air System Installation (FY 04) –Improved radiosonde technology and reporting capabilities –Sonde calibration prior to launch Version controlled surface observation processing software (FY 04) –Ensure consistency in climate data processing Published data comparison study (FY 05) –Clean switch over with documented comparison between the old and new systems

Advancing Polar Science Raytheon Polar Services Company Installation of the new SPSM Met system (OS-21) OS-21 was installed at South Pole in January, 04 –System comprised of two instrumentation suites Skiway (approach end): winds, visibility, clouds, ambient light (AL) Visibility, clouds and AL function only during flight season, winds function year round Clean Air: winds, pressure, temps, RH, solar radiation All instruments function year round Photo: Kris Perry, South Pole winter over Meteorologist

Advancing Polar Science Raytheon Polar Services Company Sensor suite and systems for OS-21 Visibility sensor: Belfort, model Ambient light sensor: Belfort, model 6300 Ceilometer: Eliasson, CBME-40A Solar Radiation sensor: Li-Cor pyranometer, LI-200SA Barometers: Druck, RPT-410 Temp/RH sensors: RM Young, Windbirds: RM Young, SQL 2000 Server and database Visual displays in Met office and Comms

Advancing Polar Science Raytheon Polar Services Company OS-21 – Parts is parts Field Data Collection Unit (FDCU): Collects, processes sensor data and sends to the Terminal Data Acquisition Unit (TDAU) via Ethernet connection. FDCU houses barometers (3), Zeno 3200 datalogger, serial sensor expansion module (SSEM), comms links and power supply. Resides at the bottom of tower. Terminal Data Acquisition Unit (TDAU): Responsible for data acquisition, processing, formatting, sorting, distribution of data received from FDCU. Is MS SQL 2000 Server, resides in the NOC.

Advancing Polar Science Raytheon Polar Services Company Visual Display of OS-21 Includes Network Connection to South Pole LAN providing graphical displays (via AWA software) directly to Met office and Comms Allows Comms to provide wind and altimeter data on demand with no need to contact Met office. Avoids conversion errors by providing calculated altimeter as opposed to a visual chart conversion Photo: Kris Perry, South Pole winter over Meteorologist

Advancing Polar Science Raytheon Polar Services Company Initial OS-21 Comparisons - Visibility Limitations – provided by Coastal Environmental Systems Isolated fog causes the most problems: Lower visibility if fog is localized to sensor Fog confined to skiway may go unreported When visibility changes rapidly, OS-21 observation will lag actual weather (several minutes). Algorithm responds more quickly to rapidly decreasing visibility than rapidly increasing visibility. On bright, sunny days with haze, sensor will report higher visibility than observer. NWS advises: Reduce reported vis 50% if it’s bright enough to wear sunglasses and there’s haze or thin fog with clear sky above (a typical day during the South Pole summer).

Advancing Polar Science Raytheon Polar Services Company Visibility: SPSMS vs. Observer Initial Analysis 337 METAR observations were compared for the month of February, 2004 Very limited amount of data, study is extremely limited and high level at this time Photo: Paddy Douglas, South Pole Logistics Supervisor

Advancing Polar Science Raytheon Polar Services Company Initial Comparison Results Visibility - SPSMS vs. Observer 41% of observations matched exactly 15.4% of observations had SPSMS calling lower visibilities than observer 43.6% of observations had Observer calling lower visibilities than SPSMS –96.4% of matching observations called unlimited (9999) visibilities –61.5% observer is calling unlimited (9999) visibility –51% SPSMS is calling unlimited (9999) visibility Photo: Kris Perry, South Pole winter over Meteorologist

Advancing Polar Science Raytheon Polar Services Company Visibility – Frequency Distribution 41% no difference – overwhelmingly during high visibility situations 33% within 1 ¼ miles 26% differ between 1 ¼ SM 6 SM – need to explore these situations more extensively

Advancing Polar Science Raytheon Polar Services Company Visibility Comparative Breakdown During high visibility situations, observer and OS-21 compare extremely well except for a few specific circumstances OS-21 calling lower visibility and observer is calling unlimited, it is probably due to prop wash or localized ice crystals near the instrument, yet to be proved out next summer Observer calling lower visibilities than OS-21 –51% show OS-21 calling unlimited visibilities while the observer is calling on average over 1 ¾ SM less (prop wash?) Calls for more intensive investigation FY04, can’t just assume OS-21 is correct, needs to be validated with observed visibilities

Advancing Polar Science Raytheon Polar Services Company Performance of OS-21 Ceilometer Ceilometer –South Pole cloud heights difficult to determine –Observer support only, no plans to rely on ceilometer for cloud observations –Currently, data only available during flight season –Readings are a result of a 30 minute average – Cannot report cloud types, therefore cannot anticipate changes in weather based impending cloud conditions. –Can’t distinguish between clear and unable to determine –May lag actual weather due to rapid changes –Laser Beam Ceilometer only sees one spot. But 30-min. average creates accurate observation in stable conditions.

Advancing Polar Science Raytheon Polar Services Company Current South Pole Ceilometer Status Began experiencing issues with the ceilometer on February 2 nd Limited comparisons at this time All that is currently known is that ceilometer did determine clouds vs clear consistently with observer and at a coverage close to what observer called Fog can cause inaccurate readings Pole ceilometer currently in storage for the winter Will add insulated “Sponge Bob pants” FY05 and bring back on line Will attempt to keep ceilometer running as long in to winter as possible Photo: Kris Perry, South Pole winter over Meteorologist

Advancing Polar Science Raytheon Polar Services Company Outstanding Issues Report file formats will be changing (surface and upper air) Difference in calculation of climatological averages –NCDC method –WMO method –Re-issue of previous years climate files Corrected climate data files Disparate data records existing within different organizations (NCDC, AMRC, BAS) Need published comprehensive comparison study