new activities to expand the caribbean sounding and surface networks the iasclip and coconet...

New activities to expand the Caribbean sounding

and surface networks

The IASCLIP and COCONet initiatives

Michael.Douglas@noaa.gov

National Severe Storms Laboratory/NOAA

Norman, Oklahoma

Two distinct activities with overlapping interests in the Caribbean region

• IASCLIP - Intra-Americas Study of Climate Processes (NOAA initiated effort to improve climate prediction over the region between North and South America)

and...

• COCONet - Continuously Operating Caribbean GPS Observational Network (NSF Funding, implemented by UNAVCO, which is “a non-profit membership-governed consortium, facilitates geoscience research and education using geodesy.”

Science questions related to COCONet

COCONet principal objective is to measure crustal motion

Source: COCONet proposal

Source: UNAVCO

Typical GPS site

Bedrock (ideally)

Source: UNAVCO

Precipitable Water and Slant Water

• SW can be estimated along single GPS ray paths

• Simultaneous observations along 10-12 ray paths

• PW is essentially an average of SW (after they have been

scaled to zenith)

(From Braun and Rockin 2001 AMS)

Precipitable Water and Slant Water

Suominet real-time displays provide the PW and output from the surface station, among other things...

PW value is 1) high time resolution and 2) absolute accuracy to compare with other measurements

(From Vaisala VXT520 users manual)

Used for GPS-MET Temp and Pressure data

Not ideal for wind measurementsbut inexpensive ~$2K

COCONET OVERLAPS IASCLIP TO CERTAIN DEGREE

Mexico GPS network also being planned...~100 sites

Fig courtesy PEnglehart/ADouglas

May-Oct PW climo (mm)

PW values don’t explain precip variability at small spatial scales

Where GPS PW really helps - detecting biases in radiosonde data and Providing long-term trends that are believable - Reanalysis validation

Suspicious!Suspicious!

Possible radiosonde networkwith adaptive (white) sites

(was part of JHT proposal this year)COCONet sites close to all RAOB sites

IASCLIP = Intra Americas Study of Climate Processes

A CLIVAR-VAMOS Monsoons Program (FY09 - FY14)

Possible radiosonde networkwith adaptive (white) sites

(was part of JHT proposal this year)

IASCLIPWeb site...

IAS centerpiece: Western Hemisphere Warm Pool (WHWP)

2000

Small WHWP

Fewer tropical storms

2005

Large WHWP

More tropical storms

IASCLIP: Predicting IAS summer climateEmphasis on extreme events

1. Identifying and Quantifying Sources of Predictability

(WHWP, Local vs. Remote Influences, Land-Atmosphere Interactions, NASH, LLJ, Orography …)

2. Climate foci: TC activity, dry summers, Midwest floods, early/late rainy season onset, Mid-summer drought anomaly

3. Multi-Space and Time scale Issues:

WHWP scale — How SST is forced by large scale phenomena (ENSO, NAO, Amazon); how WHWP affects moisture flows, vertical shear, CAPE

Mesoscale — diurnal heating and orography modify large scale regime over islands & Central America

Sfc in-situ (small islands) — rain gauges, solar radiation & wind to provide ground truth for large scale models and verify/improve satellite products over ocean areas.

Sfc in-situ (large islands, isthmus) — provide data for understanding scale interactions and for downscaling. (This is where people live, so forecasts are critical in these areas.)

Soundings: evaluate need and feasibility of regular observations in priority areas, perhaps adaptively.

Add thermistor chains to NDBC buoys — 3D development of warm pool & heat budget.

Can be real-time for climate monitoring (CPC, NCDC) and hurricane forecasting (NCEP, NHC, also some NWS local offices).

Could be fine-tuned as needed to satisfy changing needs of research community.

An IASCLIP monitoring effort should evolve into a sustainable climate observing system for the region.

Advantages of monitoring efforts

Caribbean soundings are historically unreliable(compare with San Juan at bottom) - CHUAS needs reworking

Lack of GPS-reported T(z) profiles in the IAS (1999-2005)

What is lacking in ocean measurements?

Failed Nov-22-2009

Failed Jan 13 2011

Buoys costly to maintain, slow to fix...

Small islands in Caribbean region- a unique opportunityfor establishing low cost surface and raob sites

Colombian and Jamaican islands...with facilities and logistical arrangements

Jamaican cays

Serranilla

Pedro Cay, Jamaica

Inexpensive radiosonde systems can be used for adaptive tropical soundings, simplifying logistics and reducing annual costs.

IASCLIP may apply this concept for higher spatial density measurements at lower temporal resolution. Same procedure can be applied to measuring hurricane environment .

Possible radiosonde networkwith adaptive (white) sites

(was part of JHT proposal this year)

Adaptive obs’s ~$75K / summer

Possible surface met sites in western Caribbean (some overlap possible between IASCLIP and COCONet)

Current NOAA Met buoys in red - may add thermistor chains for IASCLIP

Why are all these observations important?

• Allow for more effective use of hurricane aircraft resources

• Better specification of climate and its long-term variability

Summary

1. GPS-Met sites going into Caribbean region starting this year (10) and next year (40). Substantial Mexican GPS-Met network likely - timeline and details unclear at the moment.

2. IASCLIP observational component should be a mix of mostly climate-oriented measurements, though some have potential for real-time hurricane analysis/forecasting. Funding of IASCLIP uncertain.

3. The above are likely to provide an improved envelope of observations for hurricane-focused measurements for research and forecasting.