Thursday, December 15, 2011

Snowy September

Initiation of the 2011-12 wet season has been rather unusual at Quelccaya. A typical, dry August continued into the first week of September, and then the remainder of the month was quite snowy. Net accumulation for the month amounted to 30-40cm, ranking 2011 as one of the snowiest Septembers in our short record (since 2004). Both October and November were relatively dry, with no net accumulation apparent in telemetry data through early December. In this sense, wet-season initiation resembles that of last year; no surprise given continuing La Nina conditions in the Tropical Pacific.

Monday, August 8, 2011

AWS GigaPan

This image of the weather station is tiled composite which allows you to zoom in and explore the station in detail. In this case, 54 images from a robotic camera were stitched together to form a 43° field of view comprised of 24,128 x 12,048 pixels. GigaPan is a development of the Global Connection Project; read more and find links to images and equipment here, and click here or "GigaPan" on the image below to open a fullsize version in another tab.

The GigaPan page for this image has a series of "snapshots" which provide detail on each of the AWS components and sensors. If we missed any, please let us know!

Friday, July 22, 2011

Vamos a la playa!

Quelccaya fieldwork for 2011 is complete. Although we experienced greater lower-elevation snowfall and higher summit wind speeds than in previous years, fantastic personnel and considerable persistence prevailed. During 6 days up top at the weather station, we recovered data, performed annual service, restored telemetry, collected air samples (for the stable isotopic composition of water vapor), installed an automated "RimeCam", shot GigaPans, and conducted snowpit measurements. Meanwhile, other members of the group documented previously unknown aspects of bird ecology (e.g., another species roosting in crevasses; a collection of bird photos from the trip is here). Data are actively being organized and archived, even as initial inspection begins.

From Quelccaya the group dispersed for home, Bolivia, and coastal Perú. Several days in Paracas National Reserve was the perfect way for two of us to wrap up the trip. Traveling by Oltursa bus - with wifi - was relaxing and comfortable.

A sampling of photos follows, showing (top to bottom) the AWS ready for another wet season, departure from the summit, and a Paracas beach; more soon! Special thanks this year to Carsten Braun, Koky Casteñeda, and as always - Felix Vicencio and family.

Tuesday, June 28, 2011

Cusco Arrival

Smooth traveling to Cusco, arriving yesterday on time and with all 11 pieces of baggage! After a quick nap we began hydrating and hiking (slowly), adjusting to the altitude. With the Inti Raymi festival over, Cusco is less busy than we've experience in recent years. The second image above provides a unique perspective on our hotel (...actually a compositing mistake, the artistic merit of which we are debating).

Arriving before us from Scripps is another member of our group, Dave Chadwell. Dave was a member of the 1983 team which drilled Quelccaya's first ice core, and is back with high-accuracy GPS equipment attempting to relocate his strain network on the glacier and assess the magnitude of thinning over ~20 years. It has been very pleasant getting to know him, and we look forward to having him Dave along.

The next few days will be filled by organizing and acclimatizing, with departure for the field on Friday.

[UPDATE Tues. evening:  we had a brief chance to meet with Meredith Kelly (Dartmouth College) and Colby Smith this morning, on their way through Cusco after a very successful effort coring lakes around the Quelccaya margin. Temperatures were lower than normal until this week, with the snowline still right at the ice margin.]

Wednesday, June 22, 2011

Blogging from anywhere!

In 1996, we periodically updated a website with reports from our fieldwork on Nevado Sajama in Bolivia (6,542 m). The Inmarsat mini-M and laptop technology worked well, despite being cumbersome and requiring several additional steps by our Climate Center manager, Frank Keimig. For this trip, we will try to send at least brief updates via a much simpler system using SMS via our Iridium phone. The following was just entered directly onto this blog, prior to the editing above:  "Test of updates by satphone."

Sunday, June 19, 2011

Fieldwork Preparations

Fieldwork at Quelccaya is most efficiently done during the dry season, now well underway. Predominantly clear skies result in low temperatures at night and abundant solar radiation during the day. This year we will visit the glacier in early July to recover meteorological measurements, service the instruments, spend time in snowpits measuring density and temperature profiles, and investigate changes in glacier thickness and marginal position.

Preparing for fieldwork in such a remote location is rather painstaking, to insure that the work goes smoothly on site. That requires attention to nitty-gritty details; there are no hardware stores anywhere near Quelccaya, and time spent modifying anything is essentially wasted. This image illustrates just some of the components required for increasing the weather station tower height. Gathering them together is bad enough, but that isn't the whole story. Some parts, such as those on the right, must be custom made on a metal lathe in the UMass Geosciences machine shop. Ace machinist John Sweeney produces these with precision suitable for a NASA mission. Even standard structural fittings (e.g., crosses at top of image) are inspected closely and molding burrs are filed off to prevent problems during assembly. They are then washed with detergent to help keep smudges off equipment such as radiometer domes.

Countless other tasks also require attention. An unexpected aspect of the forthcoming trip will be changing the GOES satellite transmitter, as telemetry suddenly ceased with the 4:46 am transmission on 24 May. Detective work at the Climate Center in conjunction with Doug Neff at Campbell Scientific suggests likely failure of the existing transmitter's GPS time-keeping function. Accompanying the new transmitter on this trip will be an assortment of other parts, some for regular replacement or recalibration and others just in case they are needed. Deciding exactly what to bring is always tricky, requiring a balance between the probability of their being needing against their weight and cost.

Wednesday, May 25, 2011

2010-11 accumulation

Snow accumulation on Quelccaya has ended in recent years by the second half of May. In some years (e.g., 2005, 2006, 2010), peak accumulation was reached during April. Only in 2009 was there a minor snowfall event after mid-May.

The pattern of accumulation this year has exactly paralleled the other La Niña year (2008) since late April, with one snowfall event of ~20 cm during the second week of May. In terms of snow depth, this year saw only ~10 cm less accumulation than 2008 and ranks second since our measurements began in 2003.

Planning is underway for fieldwork in early July. At this time detailed density and temperature profiles will be made at the weather station, which will determine accumulation for the year in more meaningful terms of water equivalence. We also hope to dig one or more snowpits upwind of the AWS to assess any precipitation gradient on the ice cap. Most importantly, this fieldwork will recover the first high-accuracy humidity measurements made at any high-elevation AWS. These 5-minute interval measurements began on 3 June last year, so now span an entire year.

Fieldwork for 2011 will also include several interesting and potentially very valuable collaborations, looking into the isotopic composition of water vapor, ice volume changes over the past 25+ years, and avian ecology. Stay tuned!

Tuesday, February 22, 2011

Snow accumulation updates

A subset of Quelccaya AWS measurements are transmitted from the station to our Climate System Research Center at UMass, via the geostationary-orbit GOES East satellite. Among the most-interesting values to follow is snowfall, which principally governs Quelccaya Ice Cap mass balance and responds rather sensitively to conditions in the Tropical Pacific Ocean (e.g., ENSO).

The 2010-11 accumulation season began late - at the end of November - by which time 30-60 cm of snow typically blankets the summit. Through December, January and February to date, accumulation has been steady, and snow depth is now at ~1.5 meters. While slightly less than normal for the date, the rate of accumulation remains high - in contrast to other years when the rate tends to decrease about now.

With the Oceanic Enso Index still low (-1.4°C), snowfall over the next month or two is expected to be above normal at the station. Another 50 cm will bring 2010-11 to the mean depth (2004-09; cf. water equivalance, determined during fieldwork), and another 100 cm will make this the greatest accumulation for the period of record. Interannual variability of snow depth is remarkably low at Quelccaya!

[UPDATE 3/10:  As of 6 March, accumulation is approaching 1.9 meters. Snowfall to this date was only greater during the 2007-08 wet season (during our relatively brief period of record, 2003 to present).]

[UPDATE 4/27:  The rate of accumulation decreased notably after early March, coinciding with the lessening OEI anomaly, with the seasonal total now at ~2.2 meters. Although only 2007-08 saw greater accumulation to this date, the annual differences are small.]

Monday, January 31, 2011

Air Temperature Measurements [updated]

Quelccaya's automated weather station (AWS) is providing a unique perspective on the tropical mid-troposphere, documenting modern climate at one of the world’s most important high-elevation paleoclimate sites. Air temperature data from the station are now available through the links below.

A brief synopsis of paleoclimate research on Quelccaya Ice Cap (with images) is available here. A paper presenting the 2003 ice core record – spanning over 1,600 years – is well underway.

In conjunction with Quelccaya paleoclimate research, meteorological instrumentation was operated at several locations on the glacier through the late 1970s and early 1980s. The objective was to begin characterizing the largely-unknown climate at high elevations in the Andes, an effort carried out collaboratively with Stefan Hastenrath. Despite working with equipment that is considered rather unreliable by today’s standards, several publications resulted.

During the 2003 ice-core drilling expedition, meteorological measurements resumed – with modern electronics, satellite telemetry, and a new tower design. Images of the new AWS can be seen at the link above, and here.

AWS data
Measuring atmospheric properties is not trivial, especially when the goal is to assess any change in central tendency, variability, or extremes over time (i.e., climate). A set of ten climate monitoring principles proposed by Tom Karl at NOAA provides a succinct starting point to learn more about issues involved.

At the summit of Quelccaya Ice Cap the AWS is seen only by high-flying birds for all but a few days each year. Consequently, all data require considerable processing and inspection to insure that measurements are valid and meaningful, and free of systematic errors. This process is underway for AWS measurements from a comprehensive suite of sensors (see images).

The first data being made available from Quelccaya are air temperature measurements from highly-accurate sensors developed for NOAA’s Climate Reference Network (CRN). These sensors are identical to those used for the CRN system, resulting from years of development by NOAA's National Climatic Data Center and their Atmospheric Turbulence and Diffusion Division. For detailed information on CRN, as well as data access, click here.

Quelccaya data
The following links provide access to provisional air temperature data. Please be sure to read the metadata document.
  metadata (PDF)
  hourly values
  monthly values

UPDATE 3/25/2014:  A complete record of quality-controlled hourly air temperatures for July 2007-June 2009 are available here, as well as the accompanying metadata, and these values should be used rather than those above - which were provisional. The full 2007-13 period has been processed, yet these are not yet available due to insufficient fan speed during early-morning hours through a portion of this period. Maximum daily temperatures were largely unaffected and this series will be available soon. Thanks for your patience.]

Contact for any questions or comments:

Friday, January 21, 2011

2010 Fieldwork Images

Fieldwork in 2010 took place in late May and early June, shortly after the accumulation season ended. Over the course of 5 days at the summit, we raised the weather station tower, added new instrumentation, and conducted snowpit measurements. The following links provide access to images of the fieldwork.

The full field season is depicted here, beginning in Cusco.

For more detail about the automated weather station (AWS), images are available here.

Ascending to the summit on May 3oth, we encountered a surprise (shown here). Equipment installed on the glacier in June of 1978 emerged from the ice after being buried for 32 years.