The Mauna Kea Weather Center: the need for custom forecasts Steven Businger, Tiziana Cherubini and R. Lyman

The Mauna Kea Weather Center: the need for custom forecasts – Telescope mirror temperature – Telescope wind shake – Precipitable water – Seeing and C n Forecasts of Observing Quality MKWC HPC System

2 - Weather Hazard Mitigation – Tropical cyclones – Cold frontal passages – Upper level troughs/lows – Strong subtropical highs (strong summit winds) – Kona lows

Brief History of Weather Center l Memorandum of understanding between UH Meteorology & IfA established the Mauna Kea Weather Center in July l Three principal objectives: (i) Provide weather forecasts and nowcasts for MKO. (ii) Determine and forecast conditions that provide the best astronomical observing conditions. (iii) Communicate forecasts, meteorological data, and imagery to observatories.

Current Status l MKO forecasts issued twice daily, Monday through Friday MKO forecasts l Twice Daily WRF runs l Satellite and model data feeds from NWS & Unidata l Satellite and model graphics presented on web site l Comprehensive data archive maintained l New WRF products under development l WRF case study research ongoing

Synergy with Broader Community

l WRF is an NCAR- and community-supported research and forecast model. l Data assimilation effort (LAPS) for WRF in collaboration with NOAA ESRL. l Data sharing, web distribution, and data archive development in collaboration with Unidata and UH Meteorology. l GPS IPW in collaboration with UH Geophysics and NOAA. l Calibration and assimilation of lightning data in collaboration with ONR and NASA. l COSMIC project: refractivity data from limb-sounding technique l Utilization of high performance computer resources available at NCAR and MHPCC.

mkwc.ifa.hawaii.edu Two Linux Servers provide – –Data ingest –Data assimilation and WRF input –Graphic/Web –Redundant product distribution –Archive function

Silicon Mechanics HPC The MKWC HPC system is comprised of 16 compute nodes, 128 CPUs (Intel Xeon L5420 Quad-Core 2.50GHz), with high-speed communication links between nodes (Infiniband cards and switches). The system includes a RAID-6 storage component.

Key Variables in Twice-Daily MKWC Forecasts l Cloud cover, fog, precipitation l Summit winds and temperature l Precipitable water l Seeing, C n 2, and wind profiles

Research Challenge: Seeing Forecasting l Obtain fine vertical and horizontal resolution forecasts of temperature, wind profiles and turbulence related variables from WRF  C n 2 algorithm prediction l Provide optical turbulence parameters by integrating the C n 2 profiles l Validate and refine the optical turbulence algorithm

The MKWC has been issuing operational quantitative seeing forecasts since the summer of seeing forecasts A posteriori, the forecaster qualitatively/quantitatively validates his forecast, thus gaining experience. An inventory of the daily data received at the MKWC is under construction. This will allow observed weather conditions to be correlated to observed seeing conditions.inventory Learning from the daily forecast experience

Quantitative validation Learning from the daily forecast experience

l Study sensitivities of Cn2/seeing forecasts. l Tune model physics configurations to increase overall accuracy. l Incorporate 3-D VAR data assimilation into model & assess impacts. l Investigate weather patterns leading to especially good or bad seeing. l Comprehensive WRF forecast validation. MKWC Goals

l Increase the skill of conventional and seeing forecasts with help of validation statistics. l Provide forecast variables with finer temporal and spatial resolution. l Issue longer-term seeing forecasts.

Book on Seeing The measurement and impact of Atmospheric Turbulence and Refractivity on the Propagation of Extraterrestrial Radiation Introduction 1. Atmospheric Turbulence Authors 1.1 Atmospheric turbulence from the perspective of a meteorologist………….………………..(Raman) 1.2 Atmospheric turbulence for astronomy…………………………………………….………..….(Vernin) 2. Instrumentation for Observing Optical Turbulence 2.1 Remote optical turbulence sensing: present and future………………………….………..(Tokovinin) 2.2 Standard and commonly used optical turbulence profilers ……………………..………(Chun et al.) 2.3 Seeing by site monitors versus VLT image quality …………………………………...(Sarazin et al.) 3. Adaptive Optics - Interferometry 3.1 Introduction to Adaptive Optics: The Quest for Image Quality……….…(Businger, Tokovinin et al.) 4. Modeling Optical Turbulence 4.1 The “Missing Link” Between Meteorology and Astronomy…………………………...(Simons & Roy) 4.2 Optical Turbulence Modeling and Forecast. Towards a new era for ground-based astrononmy………………………………………….(Masciadri) 4.3 An operational perspective for modeling optical turbulence……………………………….…(MKWC)

Status l Most of the papers have been reviewed. l Formatting l Glossary l Editing issues l Deadlines: –Draft by the end of the year –Published by spring 2009

Thank you to the contributors April 14, 2008http://mkwc.ifa.hawaii.edu/guide

Questions?